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SUMMARY PROJECT A five-year research program is proposed to expand the theory of community assembly from its current base of correlative inferences to one grounded in process-based conclusions derived from controlled field and laboratory experiments. Northern pitcher plants, Sarracenia purpurea, and their community of inquiline arthropods and rotifers, will be used as the model system for the proposed experiments. There are three goals to the proposed research. (1) Inquiline assemblages that colonize pitcher plants will be developed as a model system for understanding community assembly and persistence. (2) Field and laboratory experiments will be used to elucidate causes of inquiline community colonization, assembly, and persistence, and the consequences of inquiline community dynamics for plant leaf allocation patterns, growth, and reproduction, as well as within-plant nutrient cycling. Reciprocal interactions of plant dynamics on inquiline community structure will also be investigated experimentally. (3) Matrix models will be developed to describe reciprocal interactions between inquiline community assembly and persistence, and inquilines' living host habitats. As an integrated whole, the proposed experiments and models will provide a complete picture of linkages between pitcher-plant inquiline communities and their host plants, at individual leaf and whole-plant scales. This focus on measures of plant performance will fill an apparent lacuna in prior studies of pitcher plant microecosystems, which, with few exceptions, have focused almost exclusively on inquiline population dynamics and interspecific interactions. Plant demography of S. purpurea will be described and modeled for the first time. Complementary, multi-year field and greenhouse experiments will reveal effects of soil and pitcher nutrient composition on leaf allocation, plant growth, and reproduction. Press and pulse field experiments will reveal effects of leaf age and size on inquiline community colonization and persistence. Markovian models of inquiline community assembly and pitcher plant leaf allocation that describe these reciprocal interactions will be fully integrated with a matrix model of pitcher plant growth. The results also will illustrate consequences of nutrient limitations in northern bogs by clarifying the relative importance of N- and P-limitation on growth of a common bog plant. Most generally, the data gathered will enable the development, refinement, and testing of a mathematical model of community assembly in a dynamic habitat. This model will elucidate mechanistic links among community assembly, composition, and persistence; nutrient production and transfer; leaf ecophysiology; and plant growth. The results will lead to a more general and predictive understanding of community assembly and will be applicable to many other systems in which colonizing assemblages interact with living hosts, including other inquiline systems, host-parasite interactions, and plant-herbivore communities. This proposal for Research at an Undergraduate Institution (RUI) will provide undergraduates with opportunities to participate in research and develop skills in mathematical modeling. The requested support will also facilitate improvements in the research and teaching infrastructure at Mount Holyoke College.
TABLE OF CONTENTS Total No. of Pages in Section Project Summary Table of Contents Project Description RESULTS FROM PRIOR NSF SUPPORT PROJECT DESCRIPTION General Objectives Theoretical Motivation Why Pitcher Plants Preliminary Data Matrix Models of Plants, Inquilines, and their Interactions Hypotheses to be Tested Experimental Design Feasibility Responsibilities of the PIs Significance of the Proposed Research Summary of Proposed Experiments (Table 1) RUI IMPACT STATEMENT D E References Cited Biographical Sketches AARON M. ELLISON NICHOLAS J. GOTELLI F Summary Proposal Budget MOUNT HOLYOKE COLLEGE UNIVERSITY OF VERMONT G Current and Pending Support AARON M. ELLISON NICHOLAS J. GOTELLI H I Facilities, Equipment and Other Resources Special Information/Supplementary Documentation 1 1 3 14 5 4 1 1 15 Page No. (Optional) A-1 B-1 C-1 C-1 C-2 C-2 C-2 C-3 C-5 C-6 C-7 C-8 C-13 C-13 C-13 C-14 C-15 D-1 E-1 E-1 E-3 F-1 F-1 F-8 G-1 G-1 G-2 H-1 I-1
Section A B C
CERTIFICATION OF RUI ELIGIBILITY
RESULTS FROM PRIOR NSF SUPPORT A. M. Ellison BSR-91-07195 -- "RUI: Animal-plant interactions in mangrove communities" (12/91-5/95), $162,000 DEB-92-53743 -- Presidential Faculty Fellow (PFF) Award, "Marine Environmental Ecology: Teaching, Research and Conservation" (9/92-9/97 + no-cost extension to 9/98), $500,000 DEB-97-41904 -- "REU Supplement to DEB-92-53743" (6/97-8/97), $5,000 Research accomplishments -- These three awards supported a diverse set of projects addressing animalplant interactions in tropical mangrove forests. Projects included: interactions between epibenthic marine invertebrates and mangrove growth and production (Ellison & Farnsworth 1992, Farnsworth & Ellison 1996a, Ellison et al. 1996); studies of insect herbivory in mangrove forests (Farnsworth & Ellison 1991, 1993, 1997); global biogeography of mangroves and associated gastropods (Ellison et al. 1998); growth and establishment of mangrove seedlings and saplings (Ellison & Farnsworth 1993, 1996a; Farnsworth & Ellison 1996b); responses of mangroves to global climate change (Farnsworth et al. 1997, Ellison & Farnsworth 1997); and evaluations of conservation and management of mangroves (Ellison & Farnsworth 1996b, Farnsworth & Ellison 1997) and other tropical wetlands (Ellison 1998). A full list of the 24 publications supported by these concurrent awards is given in section I of the Literature Cited section of this proposal. Educational infrastructure and human resource development -- The PFF award outfitted an undergraduate ecology teaching lab; supported construction in the greenhouse at Mount Holyoke of four mangrove mesocosms originally used for the research described by Ellison & Farnsworth (1997) and now used by introductory biology, intermediate ecology & evolution, and advanced ecology classes; and allowed for purchase of capital equipment used by the PI and undergraduates in ecology classes and by undergraduates who are engaged in independent research in the PI's lab. In addition, support from the PFF award was used for curricular enhancement of the environmental studies program, which the PI has chaired since 1992. In accordance with requirements of the PFF award, the PI continued full teaching responsibilities (normally 6-9 contact hrs/wk) during the award period These three awards supported 11 senior independent honors projects, 16 summer interns working in Belize and South Hadley, 10 work-study students (a total of 28 students) in the PI's lab during 6 academic years and one sabbatical. These undergraduates are now in academic positions (1), graduate school (6), secondary school teaching (2), government jobs (2) or the private-sector work-force (15). Two students are still enrolled at Mount Holyoke. The PFF award supported a full-time technician in the PI's lab. The PI's primary collaborator, E. J. Farnsworth, completed her Ph.D. at Harvard University in 1997 with partial support from these grants. International collaborations were developed and are continuing with H. Daz (IVIC, Caracas) and B. B. Mukherjee (Bose Institute, Calcutta). N. J. Gotelli BIR-96-12109 -- "EcoSim: A proposal for null models software." (8/96-7/97), $50,000. This SGER grant supported initial development of computer software (EcoSim) for null model analysis in community ecology (available free at http://www.uvm.edu/~biology/ Faculty/EcoSim/). The current version of EcoSim (1.10) is a Windows 95 application that features a graphical user interface, data base editor, data import and export, on-line help, and complete modules for analysis of niche overlap and species diversity.
DEB-91-18962 -- "Ant lion zones: consequences of high-density predator aggregations." (1/92-6/95), $143,917. This study examined: effects of climate on aggregations of predaceous ant-lion larvae (Neuroptera: Myrmeleontidae) (Gotelli 1993); avoidance behavior of ant-lion prey (Gotelli 1996); and intra- and interspecific competition within ant-lion aggregations (Gotelli 1997). These studies resulted in 7 publications (see section II of Literature Cited), including two books (Gotelli 1995, Gotelli & Graves 1996). This award supported research projects by, and training of two graduate students, four undergraduate students, and eight high school students. The PI's current research on ant lion movement strategies and population dynamics (DEB-96-15708) and work of the PI's graduate student, Amy Arnett, on geographic variation in ant lion life history and population genetics (DEB-97-01122), both follow from results of projects supported by this award.
PROJECT DESCRIPTION I. General Objectives There are three goals to this proposed research. First, we develop inquiline assemblages that colonize pitcher plants as a model system for understanding community assembly and persistence. Second, we use a combination of field and laboratory experiments to elucidate causes of inquiline community colonization, assembly, and persistence, and the consequences of inquiline community dynamics for plant leaf allocation patterns, growth, and reproduction, as well as within-plant nutrient cycling. Third, we develop matrix models to describe reciprocal interactions between colonizing assemblages and their living host habitats. Taken together, our experiments and models will provide a complete picture of linkages between pitcherplant inquiline communities and their host plants, at individual leaf and whole plant scales. By focusing on measures of plant performance, we will fill an apparent lacuna in prior studies of pitcher plant microecosystems, which have focused almost exclusively on inquilines (but see Bradshaw & Creelman 1984, Chapin & Pastor 1995). Our results also will illustrate consequences of nutrient limitations in northern bogs (Bridgham et al. 1996, Verhoeven et al. 1996, Bedford et al. 1998) by clarifying the relative importance of and P-limitation on growth of a common bog plant. More generally, our data will allow us to further develop, refine, and test a mathematical model of community assembly in a dynamic habitat. This model will help expand the theory of community assembly from its current base of correlative inferences drawn from statistical analysis of observed patterns to one grounded in process-based conclusions derived from controlled experiments. II. Theoretical Motivation The search for general mechanisms of community assembly remains a major focus in community ecology (Drake 1990, Samuels & Drake 1997). Diamond (1975) first suggested that communities on islands could be characterized by a set of "assembly rules" deterministic patterns of distribution and abundance controlled by interspecific competition. Other investigators have extended and refined these assembly rules, hypothesizing preferred assemblages of species ("favored states" of Fox & Brown 1993) and relatively constant proportions of species sets defined empirically or statistically (Wilson & Roxburgh 1994, Wilson et al. 1995). Supporters of assembly rules argue that competition, in the form of resource preemption or competitive hierarchies, structures communities (e.g., Diamond 1975, Gilpin et al. 1986, Drake 1991). Critics of assembly rules assert that they are tautologies lacking predictive power (Connor & Simberloff 1979), or that evidence for consistent patterns of community structure, much less for assembly rules, is not
compelling (Wiens 1980). The research that we propose here presents a more powerful, explicitly experimental methodology for elucidating rules for community assembly. Most research to date on community assembly has not been experimental, with the notable exceptions of laboratory microcosm studies by Drake (1991, Drake et al. 1993), Sommer (1991), Lawler (1993), and field studies of Weiher & Keddy (1995). A major controversy over null models and statistical analysis has dominated this literature for over 20 years (Connor & Simberloff 1979, Diamond & Gilpin 1982; Wilson 1995; Stone et al. 1996). One weakness of this literature is that interactions of species with habitats have been neglected (Gotelli & Graves 1996). Either habitat variation has been ignored (Connor & Simberloff 1979), or it has been treated as a simplistic constraint in null models (Gotelli et al. 1997). Community assembly does not take place in static habitats, however, and interactions between assembling communities and their habitat may generate deterministic assembly rules. Biogenic structures can create considerable habitat complexity (Jones et al. 1997) that modifies subsequent colonization and generates community assembly rules (Dean 1981, Pringle 1985, Diamond 1986). Models of plant succession (e.g., Connell & Slatyer 1977) recognize that environments change as a result of colonization. However, these models are phenomenological, and mechanisms of facilitation, inhibition, and tolerance do not elucidate interactions between biotic habitat structures and assembling communities. In this proposal, we develop Markov models of the reciprocal interactions between a colonizing animal community and a growing plant "host," the northern pitcher plant, Sarracenia purpurea. We hypothesize that the animal community responds to changes in plant architecture, and plant architecture, growth, and reproduction in turn respond to nutrient production by the animal community. III. Why Pitcher Plants? Pitcher plants (families Sarraceniaceae, Nepenthaceae, Cephalotaceae) are excellent model systems for studies linking community assembly with habitat dynamics because these growing plants support speciesspecific inquiline communities in their pitchers (e.g., Beaver 1983, Fish 1983). Leaves (Sarraceniaceae) or tendrils (Nepenthaceae, Cephalotaceae) are modified into pitcher-shaped organs (Arber 1941) that fill with rainwater and digestive enzymes. Nepenthaceae and southern (U.S.) species of Sarraceniaceae digest prey directly with plant-secreted proteolytic enzymes (Heslop-Harrison 1978), while Sarracenia purpurea, the focus of the proposed research, derives nutrients, primarily N and P, from prey that are decomposed by pitcher-inhabiting inquilines (Hepburn et al. 1920, Plummer & Kethley 1964, Williams 1966, Christensen 1976, Bradshaw 1983, Bradshaw & Creelman 1984, Heard 1994b, Chapin & Pastor 1995). Numerous studies have described intra- and interspecific interactions among pitcher-plant inquilines (e.g., Addicott 1974, Forsyth & Richardson 1975, Bradshaw 1983, Bradshaw & Holzapfel 1992, Mogi & Young 1992, Miller et al. 1994) and food web structures of these specialized communities (e.g., Beaver 1983, Ratsirason & Silander 1996). Few studies, however, have addressed direct relationships between pitcher plants and their inquilines (Judd 1959, Plummer & Kethley 1964, Fish & Hall 1978, Bradshaw 1983, Bradshaw & Creelman 1984). Although Judd (1959) and Fish & Hall (1978) noted temporal variability in inquiline colonization of the northern pitcher plant Sarracenia purpurea, they attributed this observed variation only to leaf age. Cameron et al. (1977) noted that "studies on the fauna [are] hampered by the dual nature of the system where the life cycle of [the fauna] is superimposed on the seasonal cycle of the plant." We propose to exploit this "dual nature of the system" to study experimentally inquiline community assembly, composition, and persistence in pitchers of S. purpurea, and to examine how changes in inquiline community structure affect leaf-scale ecophysiology, whole-plant development, and production of new "inquiline habitat" (pitchers). We will develop a stage-based matrix model of pitcher plant demography that synthesizes these processes.
Sarracenia produces two kinds of leaves: pitchers and phyllodes (Fig. 1; see also Macfarlane 1908, Mandossian 1966). Whereas pitchers collect water, host inquilines, capture prey, and accumulate nutrients, phyllodes are flat and are solely photosynthetic organs that probably are more efficient at photosynthesis than pitchers (Givnish et al. 1989) in part because pitcher morphology reduces surface area intercepting light (Kingsolver 1979). Despite detailed information on the anatomy of Sarracenia pitchers (Arber 1941, Adams & Smith 1977), no one has investigated conditions inducing phyllode production, or how they differ functionally from pitchers. Production of phyllodes not only limits opportunities for carnivory, but it also reduces habitat for inquiline communities. Our central question is: do inquiline communities supply nutrients to pitcher plants and change subsequent relative abundance of pitchers and phyllodes, and does this shift in turn change inquiline community assembly, composition, or persistence?
production of pitchers and phyllodes by a single Sarracenia individual. In brief, Givnish et al. (1984) suggested that pitchers should be relatively inefficient at photosynthesis, but carnivory should be selected for as long as marginal photosynthetic costs of pitchers are outweighed by marginal gains in nutrient uptake deriving from carnivory. In high-sun environments such as open bogs, light levels are likely to be well above saturation, while extremely low nutrients available in bogs should lead to large marginal gains from carnivory. Surprisingly, key parameters needed to evaluate this model -- simultaneous measurements of light levels, photosynthetic rates, nutrients available to roots, and those derived from carnivory -- are unavailable in the literature for any carnivorous plant (see reviews by Lttge 1983, Givnish et al. 1989, Adamec 1997). Moreover, since research on Sarracenia has been focused on inquiline community structure and dynamics, virtually all existing data are derived from single, individual pitchers (e.g., Cameron et al. 1977, Weiss 1980, Joel & Gepstein 1985, Joel & Heide-Jrgensen 1985). However, nutrients are translocated among pitchers (Plummer & Figure 2 -- Conceptual model (after Kethley 1964) and initiation of leaf and inflorescence primordia are Givinsh et al. 1984) proposing that initiated one year before leaves and flowers fully develop. Thus, carnivory should evolve whenever the carbon gain and nutrient uptake in one year which may be marginal difference between dependent on pitcher:phyllode ratio, carnivory, and inquiline photosynthetic benefits of non- activities could affect the next year's pitcher:phyllode ratio, carnivorous leaves (P) and which in turn will affect possibilities for carbon gain, carnivory, photosynthetic costs of carnivorous and presence and abundance of inquilines. This observation also leaves (C) exceeds 0 (slope of dashed lines > 0). We adapt this conceptual suggests the need for multi-year experiments; however, past framework as a physiological mechanism experiments on effects of nutrient levels on pitcher plant growth for within-plant phenotypic shifts from have covered one growing season or less (Plummer & Kethley production of pitchers to phyllodes (or 1964, Bradshaw & Creelman 1984, Chapin & Pastor 1995).
vice-versa) that underpins our plant allocation model.
Figure 1 -- End-of-season (October 9, 1997) photograph of an individual Sarracenia purpurea at Hawley Bog, Massachusetts. All leaves produced by this individual in 1997 (8 red leaves in center) were Givnish et al. (1984) developed a conceptual model (Fig. 2) to explain phyllodes, while all leaves produced the restriction of carnivorous plants to sunny, nutrient-poor habitats. We in 1996 (7 dead, grey leaves) were adapt this model to generate hypotheses concerning the relative pitchers.
We hypothesize that both pitcher architecture and inquiline community structure will exhibit strong reciprocal interactions because both parties change on similar within-season time scales. On an annual time-scale, the inquiline community may alter pitcher plant reproduction and population growth. We intend to quantify directly the effects of inquiline communities on plant demography and seed set. In the next section, we present results of pilot and on-going studies that demonstrate our capacity to work with these plants in the greenhouse and the field, and to obtain data necessary to calibrate our models. We then develop a transition-matrix model that links assembly, composition, and persistence of inquiline communities to production of pitchers, phyllodes, and plant fitness (reproductive output). We propose a set of field and laboratory experiments to parameterize the linkages of our model and elucidate ecological mechanisms driving these linkages. IV. Preliminary Data We collected preliminary data in 1997 from a population of >5000 S. purpurea plants growing at Hawley Bog, a 40 ha ombrotrophic bog in northwestern Massachusetts. Principal components analysis of bi-weekly pitcher censuses (MaySeptember 1997) revealed three inquiline community types (Fig. 3): one dominated by mosquito (Wyeomyia smithii) and midge (Metriocnemus knabi) larvae, one dominated by rotifers (Habrotrocha rosa) and mites (Sarraceniopus gibsoni), and one dominated by the larva of a sarcophagid fly (Blaesoxipha fletcheri). All three community types, along with empty pitchers, were present in varying numbers throughout the summer (Fig. 4). These inquiline community types result from predation Figure 3 -- PCA biplot of pitcher-plant patterns by mosquito and sarcophagid larvae. Our laboratory inquiline communities at Hawley Bog (n = feeding experiments showed that both species eat rotifers 278 samples; individual points not shown). independent of the latter's density (Bedzki & Ellison 1997; see Fifty-three percent of the variance in inquiline community structure is accounted also Addicott 1974), thereby restricting rotifers to pitchers lacking larvae of these two dipterans. Sarcophagid larvae also for by the first two principal components. eat mosquito larvae; thus mosquito larvae rarely are found in pitchers inhabited by this large fly larva. The larger size of mites and midge larvae, and their tendency to inhabit pitchers bases prevented these two inquiline species from being eaten by either mosquito or sarcophagid larvae (see also Naeem 1988, Heard 1994b). Because rotifers are important sources of phosphate (PO4-P) in aquatic ecosystems (e.g., EjsmontKarabin 1984, Wen & Peters 1994), we hypothesize that they provide P to S. purpurea pitchers. Our preliminary data suggest that Habrotrocha in pitcher plants excrete 2 ng PO4-P L-1 rotifer-1 hr-1; Bedzki & Ellison 1997). For an average population of 2,000 rotifers in 25 ml of pitcher liquor, this results in a net excretion of 2.4 Fg PO4-P/d, within the same order of magnitude as the concentration of PO4-P added to inquiline-free pitchers by Chapin & Pastor
Figure 4 -- Abundance of inquiline communities at Hawley Bog, summer 1997 (n = 278 samples).
(1995), the only other study of nutrient additions on S. purpurea growth. Thus, our data suggest that rotifers meet most or all of the demand for P by S. purpurea. Rotifers and other inquilines decrease plant tissue N:P ratios of pitchers by 6% relative to phyllodes, but N:P ratios of both pitchers (8.8) and phyllodes (9.3) imply strong N-limitation (Verhoeven et al. 1996). Other data suggest that P availability normally limits plant growth in northeastern U.S. bogs (Bedford et al. 1998; see also Richardson 1985, Richardson & Marshall 1986), but we propose that inquilines produce enough P (cf. Plummer & Kethley 1964) to make N the limiting nutrient for S. purpurea. Nitrogen fixation by bacteria within pitchers (150 Fg N pitcher-1 day-1; Prankevicius & Cameron 1991), high atmospheric deposition (and pitcher retention) of NO3-N (450 Fg/L in rainfall at Hawley Bog), and release of N by other inquilines (e.g,. Bradshaw & Creelman 1984) appear to do little to ameliorate this N limitation. The high C:N ratios we observed in both pitchers (0 = 33, n = 6) and phyllodes (0 = 38.1, n = 6) similarly suggest that availability of N limits maximum photosynthetic rates (e.g. Field & Mooney 1986, Evans 1989, Ellsworth & Reich 1992). We measured very low maximum photosynthetic rates (< 2.0 Fg CO2 m-2 s-1) of pitchers at Hawley Bog. V. Matrix Models of Plants, Inquilines, and their Interactions We propose to use a non-stationary, stage-based matrix model (Caswell 1986, Gotelli 1991) to predict pitcher plant population growth rate and size structure. Our model takes as inputs growth, survivorship, and reproduction of individual plants based on carbon and nutrient availability. Carbon fixation will be predicted by a second model describing an individual plant's allocation to phyllodes and pitchers. Nutrient availability has two components: soil nutrients and pitcher nutrients. Availability of pitcher nutrients depends not only on the number of pitchers, but also on inquiline community structure. The latter will be modeled as a Markov model of transitions among community states dependent on individual pitcher states. We hypothesize that these transitions are driven by reciprocal interactions plants and inquiline communities. The population growth model (Fig. 5) has a time-step of one year and assumes that individual plants integrate within-year variance in (1) nutrient availability; (2) inquiline community composition; and (3) leaf physiology. The population growth model does not include explicit density dependence because pitcher plants probably are not limited Figure 5 -- Stage transition model for pitcher plants. Arrows by intraspecific competition over the range of indicate permissible transitions with an annual time step of 1 densities typically observed in the field yr. (Schwaegerle 1983). Pitcher plants will be classified as juveniles (J), non-reproductives (N), or reproductives (R). Juveniles are plants < 10 cm high and usually < 3 yrs old. Under optimal (greenhouse) conditions, S. purpurea can begin reproducing in its 3rd or 4th year, when new pitchers are normally $ 10 cm high, although reproduction in the field is rare before age 5. In the field, juveniles are easily distinguishable from potentially reproductive plants by non-overlap in their size distributions (Ellison, unpublished). Reproductive plants produce a single flowering stalk, and when pollinated, yield > 1000 seeds (Gotsch & Ellison 1997). Only one of the transition probabilities in this model is constant. The probability that a reproductive plant reverts in the following year to the non-reproductive state (PRN) equals (1.0 annual
probability of mortality for reproductive plants) because plants produce no new leaves in years when they flower, and consequently rarely flower for two consecutive years. PRN will be estimated from field monitoring of natural plant cohorts (Experiment 1, below). The other five transitions in the model are functions of soil and pitcher nutrient levels. These levels, in turn, depend on plant allocations to pitchers and phyllodes, and composition of inquiline communities within pitchers. The leaf allocation model describes annual allocation among pitchers and phyllodes. Juveniles and nonreproductive plants must allocate their average annual production of 7 leaves (Ellison, unpublished) among pitchers and phyllodes. Phyllodes may be more efficient photosynthetically, but Pmax is limited by N and only pitchers capture insects and nutrients for the plant. A non-reproductive plant can exist in one of 8 possible states (phyllodes:pitchers between 0:7 and 7:0). Hence, transitions between states can be modeled with an 8 8 transition matrix. Although all transitions are theoretically possible, we expect that most of the largest values in the matrix will fall near the diagonals, because pitcher plants usually add or remove only one phyllode or pitcher per year (Ellison, unpublished). This model will also have an annual timestep, and this transition determines the number of pitchers that will be available for inquiline colonization the following year. Initial estimates for transition probabilities will come from yearly censuses of a cohort of unmanipulated plants in the field (Experiment 1, below). We will also monitor leaf allocation in experiments that manipulate nutrients derived from soils and from inquiline processing chains (Experiments 2-4, below) The inquiline assembly model classifies plant pitchers into four community states: empty; mosquitoes + midges; rotifers + mites; sarcophagids. We will use a series of Markov models (Usher 1979) to describe changes between these four states in a single pitcher. The time-step for the model will be two weeks, and the model will run for 10 time steps, which represents the typical growing season length for pitcher plants in western Massachusetts. We will use field census data (Experiment 5) to estimate transition probabilities between different inquiline community states. We will compare observed and predicted community states to test for the best fit of 3 different Markov models (Tanner et al. 1996). In a first-order model, transitions depend only on the current state of the assemblage. In a second-order model, transitions depend on both the current and the previous state of the assemblage. In a semi-Markov model, transitions depend on the absolute amount of time that an assemblage has been in a particular state. The semi-Markov model may be especially useful for this community because it will accurately describe transitions from Diptera-dominated assemblages in which larvae mature and leave pitchers after a given amount of time. Tanner et al. (1996) found that the equilibrium states for all three models were similar. However, the transient dynamics of the models were quite different, which will be important in our system because of the small number of time steps (10) within a season (see Fig. 4, above, for an example of non-equilibrium patterns of inquiline community abundance in a population of S. purpurea). These transient dynamics will be examined experimentally in Experiments 6-8. VI. Hypotheses to be Tested We propose to test two fundamental, reciprocal null hypotheses regarding linkages between community structure and temporally predictable habitat changes in pitcher-plant communities that derive from our models and observations to date: ! Inquilines produce no detectable changes in the ratio or pitchers to phyllodes and subsequent measures of plant performance: leaf nutrient status, photosynthetic rate, individual growth, seed production, or population growth.
! Seasonal variability in plant status -- leaf size or age, ratio of pitchers to phyllodes, reproductive effort -- has no impact on pitcher-plant inquiline community assembly, structure, or persistence. These two general hypotheses will be tested with a set of eight greenhouse and field experiments. Experiment 1 parameterizes the population growth model. The remaining seven experiments parameterize the other two models using ecological data collected on the interaction paths illustrated in Fig. 6. A summary of all the experiments, the models and interaction paths they address, and the experimental time line is presented in Table 1 (page C-14). Path I -- This path links inquiline communities with plant nutrient status, at the level of individual leaves, and will be addressed with Experiment 2. The results will be used to estimate parameters of our leaf allocation model. Path II -- This path links individual leaf nutrient status directly with whole-plant status, and will be addressed with Experiments 3-4. These experiments will provide additional supporting data for our leaf allocation model, and link whole-plant effects to our plant population growth model. Path III -- This path links individual pitcher status (size at opening and age) and whole-plant status (ratio of pitcher leaves to phyllode leaves) to inquiline community assembly, composition, and persistence. It will be examined with Experiments 5-6. The results will be used to estimate parameters of our inquiline assembly model.
Figure 6 -- Explicit linkages between pitcher-plants and inquilines that will be examined by our proposed experiments. For clarity, we draw arrows representing unidirectional interaction paths, but we recognize, and our experiments test, that these interaction paths may be two-way. Processing chains, have been studied thoroughly by Heard (1994b). Direct microbial decomposition of prey independent of inquiline macrofauna, here incorporated into residual variance, will be the subject of a subsequent research proposal.
Path IV -- This path links individual pitcher status (size at opening and age) and whole-plant status with prey capture rates on which inquiline communities depend for sustenance. Experiments 7-8 will clarify the importance of inquiline processing chains in providing nutrients available for plant growth. The results define links among our models of inquiline assembly, leaf allocation, and plant growth. VII. Experimental Design Experiment 1: Field demographic monitoring. We will obtain baseline values for transition probabilities of the population growth model from two bogs, Hawley Bog in Massachusetts and Molly Bog in Vermont. Field data from two locations will allow us to assess the generality of our model beyond a single site. In April 1998, we will locate and permanently flag 100 randomly-selected juvenile plants (pitcher size < 10 cm) and 100 randomly-selected adult plants (pitcher size $ 10 cm) growing at each bog. These plants will be monitored annually for four years to determine annual stage transition probabilities (Fig. 5), flowering, and seed set. We also will establish ten, randomly-located 1-m2 quadrats in each bog from which we will
remove all juveniles. Subsequent seedling recruitment in these quadrats will be used to estimate reproductive to juvenile (successful seeding) transition probabilities (as a function of local adult density). Experiment 2: Inquilines, nutrients, and leaf allocation. This experiment tests the null hypotheses that inquilines have no effect on plant nutrient content, individual leaves, or whole plants, and that there are no interactions between nutrients derived from soil and pitchers. Three hundred and eighty-four plants will be grown hydroponically in sterile quartz sand in six 2626 cm flats, each partitioned into sixteen 66 cm cells using plastic flat inserts. Seeds will be stratified for 6 weeks at 4o C prior to surface sowing (2 seeds/cell). Sown flats will be placed on greenhouse benches under natural light at 25o C and misted daily with distilled water until seedlings appear. We have obtained 85-100% germination of S. purpurea seeds within 3 weeks using this technique (Gotsch & Ellison 1997). Cells will be thinned to 1 plant/cell; extra seedlings will be transplanted into cells in which no germination occurs. Seeds will be planted in late February 1998, so that the proposed experiments can be initiated immediately upon receipt of grant support. Once seedlings begin to produce pitchers in early summer, each flat will be randomly assigned to one of four soil nutrient treatments (cf. Christensen 1976, Cresswell 1991, Chapin & Pastor 1995, Adamec 1997): control (distilled water); N-only (150 mM NH4Cl solution); P-only (20mM NaH2PO4); N+P (combination of above). Nutrients, along with balanced micronutrients (Chapin & Pastor 1995) will be mixed into distilled water and cells will be maintained at saturation by filling flats with the appropriate nutrient or control solution. Within a flat, each plant will be assigned at random (in a replicated latinsquare design) to one of the three inquiline treatments identified in our field sampling (rotifers + mites; mosquito + midge larvae; sarcophagid larvae) or an empty control. Identical inquiline communities and densities or pitcher nutrients will be maintained in each plant during each of four successive growing seasons (a press experiment, sensu Bender et al. 1984). Each pitcher on a plant will be filled half-way with distilled water, and then all pitchers on a given plant will be assigned to a single inquiline community treatment. Because pitchers vary in size and volume, inquiline communities will be assembled on a per ml (density) basis based on the average density of each species observed in our 1997 sampling: 1 mosquito per ml; 1 midge per ml; 80 rotifers per ml; 6 mites per ml; 1 sarcophagid per pitcher (independent of volume). Note that the density of mosquitoes and midges we observed in the field and that we will use in these experiments is well below that at which density-dependent interactions have been found to affect larval success or adult fecundity (Istock et al. 1976). First and second instar inquilines will be derived from current lab cultures, except for the sarcophagid, first-instars of which will be collected in mid-June. As larvae metamorphose into adults, they will be replaced to maintain constant densities of larvae throughout the growing season. As new pitchers are produced, they similarly will be half-filled with distilled water and identical inquiline communities will be introduced into the new pitchers. Inquiline communities will be fed 1g of housefly (Musca domestica) corpses once/wk. Greenhouse benches will be caged with fine screening (light reduction < 10%) to prevent unwanted colonization of pitchers or uncontrolled prey capture by pitchers. As plants outgrow their cells, they will be transplanted to prevent root-binding, and to avoid interference between leaves of adjacent plants. This experiment will run for 4 years, which is the expected length of time required for S. purpurea grown from seed to reach reproductive maturity. We expect to see, and will document, ontogenetic changes in plant responses to inquiline community structure. Experimental manipulations will be carried out during normal growing seasons (April through October) each year, and plants and inquilines will be allowed to go dormant each winter (Paterson 1971, Paterson & Cameron 1982). Except for when seeds are germinated, the greenhouse will be unheated (to allow for winter dormancy), and natural light will provide normal photoperiods for these plants.
Response variables to be measured will be (1) pitcherliquid nutrient concentration and pH (using ion-sensitive electrodes for NO3-N, NH3-N, and Ca, pH electrode, and standard spectrophotometric methods for PO4-P [APHA 1985, Fresnius et al. 1988]); (2) pitcher size (height, opening diameter, volume, dry mass); (3) tissue nutrient content (C, H, N, P, Ca, Mg, K) at the end of the summer (using a C-H-N analyzer, and atomic absorption spectrophotometry for P, Ca, Mg, K [Ma and Rittner 1979]); (4) rates of photosynthesis of phyllodes and pitchers (measured with a Li-Cor 6200 IRGA and custom-built cuvette; Fig. 7); (5) respiration rates of inquilines (measured with a Hansatech DW2/2 oxygen electrode); (6) rate of new leaf production and relative proportion of pitchers and phyllodes produced; (7) years Figure 7 -- Custom-built 8-L cuvette for to first reproduction and consequent seed set. measuring leaf-level and whole-plant This experiment is set up as a split-plot design, and photosynthesis of Sarracenia purpurea. A results will be analyzed using mixed-model ANOVA (for single pitcher is visible within it. The cuvette parameters measured only once, such as reproductive effort and is constructed to Li-Cor specifications and success) or mixed-model repeated-measures ANOVA (for connects to a Li-Cor 6200 photosynthesis parameters measured annually for five years, such as growth or system. A similarly constructed, 4-L cuvette nutrient content). Total sample size (n = 384) will be sufficient also has been built for smaller plants. to give statistical power > 0.90, based on sample variances reported by Chapin and Pastor (1995). A power analysis of their published data suggests that they may have failed to find an effect of nutrient treatments because their statistical power was < 0.5. All analyses will be done using S-Plus for Windows, version 4.0 (MathSoft 1997). Experiment 3: Leaf allocation and nutrients alone. This experiment tests the null hypothesis that nutrient content of the pitcher liquid by itself has no effect on plant growth, types of leaves produced, or leaf nutrient status and that there are no interactions between nutrients derived from soil and pitchers. This experiment will be structured in the same way as Experiment 2, but the inquiline community will be replaced with known concentrations of nutrient solutions: control, low N (15 mM), high N (150 mM), low P (2 mM), high P (20 mM), and the three possible N+P treatments that vary in N:P ratio (15:2, 15:20, 150:2). All pitchers will receive balanced micronutrients (Chapin & Pastor 1995). Like the previous experiment, there will be 6 flats/soil nutrient treatment, but in this experiment, there are 8 pitcher nutrient treatments (total number of plants = 384). All pitchers on a given plant will receive the same nutrient solution. Like Experiment 2, this experiment will run for 4 years as a press experiment (plants maintained in the same treatment each year). Measures of nutrient content and plant performance will be identical to those done in Experiment 2. ANOVA and repeated-measures ANOVA will be used to analyze the data. Experiment 4: Leaf allocation and nutrients under field conditions. This experiment will replicate Experiment 3 in the field to examine whether pitcher-plants in the field respond to nutrients added directly to the pitchers in the same way as these plants respond in the greenhouse. One hundred and sixty plants growing in full sun on the bog mat at Hawley Bog will be selected at random in April 1998 for this experiment. Each plant will be assigned to one of the eight nutrient treatments described above for Experiment 3. All old leaves will be removed, and new leaves will be tagged as they are produced throughout the summer with small, numbered plastic rings (bird bands; National Band & Tag Co.) around their petioles. As leaves emerge, but before pitchers open, they will be covered with fine mesh (white
polyester chiffon) bags to exclude oviposition by inquiline adults, as well as prey capture by pitchers. Bags will also prevent attack of pitchers by herbivorous moth larvae (Brower & Brower 1971). These bags reduce light availability by 23%, but on sunny days (> 2,000 Fmol m-2 s-1), light reaching pitchers is still well above photosynthetic saturation for S. purpurea (900 Fmol m-2 s-1). As pitchers open, they will be filled half-way with the assigned nutrient solution (all pitchers on a given plant will receive the same nutrient solution). In this press experiment, treatments will be maintained at weekly intervals during 4 growing seasons, and plants will be measured (as described above). In addition, permanent, shallow wells (capped PVC tubing, 30 cm long, 1 cm inner diameter, perforated at 2.5 cm intervals) will be installed adjacent to each plant. Monthly during the growing season (April - October), pore water samples from these wells will be sampled and analyzed for pH, redox potential, NO3-N, NH3-N and Ca. These soil nutrient data will further allow us to compare greenhouse and field soil nutrient conditions. Data from this experiment will be analyzed using ANCOVA (repeated measures where appropriate), with pitcher nutrient additions treated as main effects and local nutrient levels entered as covariates. Collectively, the results from Experiments 1-4 will be used to estimate (1) transition probabilities for the population growth model; (2) effects of inquiline communities on pitcher liquor and leaf nutrient supply; (3) effects of these nutrients on individual leaf nutrient content and photosynthesis in greenhouse and field conditions; (4) the transition matrix of pitcher vs. phyllode leaf production as a function of soil nutrient supply and inquiline community activity; (5) the relative importance of soiland pitcher-supplied nutrients on whole plant growth, primary productivity, and reproduction. Experiments 5: Pitcher status and inquiline community persistence. This experiment tests the null hypothesis that inquiline community persistence does not vary with either mature pitcher size, which it reaches prior to opening, or its age (time since its opening). Although Judd (1959) and Fish & Hall (1978) found effects of pitcher age on inquiline colonization dynamics, they did not examine community persistence. Since inquiline communities likely interact with pitchers in different ways, we expect that their persistence in pitchers will feed back on nutrient cycling dynamics revealed by Experiments 2-4, as well as alter plant transition probabilities identified by Experiment 1. We will set up a 3-way balanced factorial pulse (sensu Bender et al. 1984) field experiment [Pitcher Size Age Inquiline Community]. There will be two levels of pitcher size (< 10 cm tall, $ 10 cm tall), three levels of pitcher age (newly-opened, 3 weeks old, 6 weeks old), and three inquiline communities (rotifer + mite; mosquito + midge; sarcophagid). Sample size is 10 plants per treatment combination (total n = 180 plants). Pitchers will be marked as they are produced, and bagged to exclude colonization. Bags will be removed at the appropriate time (when pitchers are just opened, 3 weeks after opening, 6 weeks after opening), half-filled with distilled water, and seeded with inquiline communities (on a per volume basis) as described in Experiment 2. Pitchers will then be re-bagged to prevent additional colonization during the course of the experiment. Inquiline communities will be fed 1g of housefly corpses weekly. Just before feeding, inquiline communities will be extracted (using the suction device described by Nastase et al. 1991), individuals counted, their larval instars noted, and the sample photographed on a grey background (for later determination by digitization of larval sizes); then the communities will be returned to the pitcher. One-ml subsamples will be collected and rotifer density determined in the lab. Response variables in this experiment will be inquiline survivorship, growth (mean time between instars), and percent eclosion. In addition, we will monitor pitcher liquid chemistry (pH, NO3-N, NH3-N, Ca, PO4-P) as covariates that may contribute to observed variance in our inquiline response variables. Analysis will be by ANCOVA. This experiment will be replicated in two successive summers at Hawley Bog and Molly Bog (1999, 2000).
Experiment 6: Pitcher status and inquiline community assembly. This experiment tests the null hypothesis that inquiline community assembly does not vary with pitcher size or age. We will set up a 2way balanced factorial field experiment [Pitcher Size Age] (factor levels as in Experiment 5; n = 10 plants/treatment combination). Again, pitchers will be marked as they are produced, and bagged to exclude colonization until the appropriate time (newly-opened, 3 weeks old, 6 weeks old), when bags will be removed. Natural colonization of inquiline communities will be monitored weekly, along with prey capture rates by pitchers and pitcher-liquor chemistry as described for Experiment 5. Numbers of phyllodes and pitchers on the whole plant will be noted throughout the experiment, as oviposition by sarcophagids, mosquitoes, and mites may be affected by pitcher:phyllode ratio (cf. Heard 1994a). Response variables of this ANCOVA design will be inquiline colonization rate, community composition, survival rates, and overall community persistence. In addition to leaf status, inquiline survivorship and community persistence are likely to be affected by prey availability, which will be monitored concomitantly. This experiment will also be replicated twice at Hawley Bog and at Molly Bog (in 1999 and 2000). Concurrent with the experimental work on inquiline community assembly and persistence, we will monitor inquiline community composition of a separate, randomly-chosen group of 50 plants over the course of the same two growing seasons. We will sample these plants weekly as described above to determine background patterns in inquiline distribution and abundance. In particular, we are concerned that because of lack of exact concordance between insect phenology and plant leaf production rates, leaves used in Experiment 6 will not randomly "sample" the range of possible inquiline communities. Thus, this field monitoring will serve as a base-line control for this experiment. The results of Experiments 5 and 6 will be used to assess the relationship between individual pitcher traits (size and age) and inquiline community assembly, composition, and persistence. These data will be used to calibrate the inquiline assembly model. Moreover, these results will provide additional field data on the effects of inquiline communities on pitcher-liquor chemistry. The field monitoring component of Experiment 6 provides a critical check for possible temporal bias of field manipulations. Experiment 7: Prey capture, pitcher status, and pitcher:phyllode ratio. This experiment tests the null hypothesis that pitcher size and age, and pitcher:phyllode ratio has no effect on prey capture rate. Prey capture rates have been shown to decline with pitcher age (Judd 1959, Fish & Hall 1978, Wolfe 1981), but there have been no parallel experiments on capture rates or changes in prey composition with respect to pitcher size or whole plant status (pitchers:phyllodes). Our greenhouse populations provide us with the opportunity to examine relationships between prey capture rates by pitchers, pitcher size and age, and proportion of available pitchers per plant. Experiment 7 will be set up in the greenhouse as a two-way factorial design [Pitcher Size Age] stratified by phyllode:pitcher ratio (as available; minimum n = 10/treatment combination) following the methods of Wolfe Individual (1981). plants will be enclosed in fine-screened cages, and 30 flies will be released into each cage. Capture rates (carcasses/pitcher/day) will be assessed after 24 hours by removing pitcher-liquor from each open pitcher and counting number of drowned files. Each plant will be run on three successive days, once with lab-reared house-flies (Musca domestica), once with lab-reared fruit-flies (Drosophila melanogaster), and once with a mixed population of house-flies and fruit-flies (treatments in random order) to determine if capture rates differ with prey size and relative abundance. Prey density will not be varied, as both young and old leaves have a constant (but age-dependent) prey capture efficiency (proportion of prey captured) at prey densities < 200 flies (Wolfe 1981). Data will be analyzed using ANOVA. This experiment will be run once, in the summer of 2001. Experiment 8: Prey capture rates in the field, pitcher status, and pitcher:phyllode ratio. This experiment tests the null hypothesis that pitcher size and age, and pitcher:phyllode ratio has no effect on prey capture rate in the field. We will select 60 random plants at Hawley Bog, stratified by leaf size and age (as in Experiment 6). For ten weeks, we will monitor prey capture rates by pitchers on a daily in order
to assure accurate identification of prey. We also will set up a network of pitfall traps and sticky-traps to determine composition and abundance of potential prey items, both of which may be sources of temporal bias in our results. Data will be analyzed using ANCOVA. Multivariate indices of potential prey composition will be developed and used as covariates in the analysis. The results of Experiment 7 and 8 will be used to test for relationships between individual pitcher size and age, and relative pitcher availability on prey composition and capture rates. Since these prey form the basis of known processing-chain commensalisms among inquilines, and because the effects of inquiline processing chains on plant growth will have been assessed with Experiments 2-4, these last two experiments link our models of inquiline assembly, leaf allocation, and plant growth. VIII. Feasibility A 1,000 sq. ft. greenhouse at Mount Holyoke College will be dedicated to this research project. This greenhouse has temperature control and a reverse-osmosis system that delivers purified water needed to grow S. purpurea. Seeds for greenhouse experiments will be planted in February 1998, so that experiments can commence upon receipt of funding. Germination success is > 85% (Gotsch & Ellison 1997). Four seasons of experimental work will take plants from seedling through reproduction. Ellison's lab already maintains cultures of Wyeomyia, Metriocnemus, and Habrotrocha, and is developing culture techniques for Blaesoxipha and Sarraceniopus. Field sampling techniques needed were used successfully in 1997 to monitor inquilines and prey captured by pitchers. Ellison is permitted to do field work at Hawley Bog, which is partially owned by Mount Holyoke College. Molly Bog is owned by the University of Vermont, and Gotelli will obtain permits to work there. IX. Responsibilities of the PIs Ellison will perform all greenhouse experiments, and field work at Hawley Bog. Gotelli will conduct field work at Molly Bog. Gotelli will develop and test the matrix models of plant growth, leaf allocation, and inquiline assembly, and oversee plant nutrient analysis at the University of Vermont. Ellison will train and mentor undergraduates who are involved with field and laboratory work. In years 3, 4, and 5 of the grant, these students will travel each year for two weeks to the University of Vermont, where Gotelli will teach a short course in ecological modeling using the data generated from this project (see RUI Impact Statement, page C-15). Mt. Holyoke and the University of Vermont are within a 4 hour car drive of one another, and each year the PIs will make several visits back and forth for data collection and analysis. Both PIs will share equally in the analysis and publication of results. X. Significance of the Proposed Research Our proposed research focuses on reciprocal interactions between a colonizing inquiline community and its growing host habitat, the pitcher plant Sarracenia purpurea. Plant demography of S. purpurea will be described and modeled for the first time. Our complementary, innovative, and multi-year field and greenhouse experiments will reveal effects of soil and pitcher nutrient composition on leaf allocation, plant growth, and reproduction. Press and pulse field experiments will reveal effects of leaf age and size on inquiline community colonization and persistence. Markovian models of inquiline community assembly and pitcher plant leaf allocation that describe these interactions will be fully integrated with our model of pitcher plant growth. Most generally, our proposed research will elucidate mechanistic links among community assembly, composition, and persistence; nutrient production and transfer; leaf ecophysiology; and plant growth. The results will enhance our general understanding of community assembly and will be
applicable to many other systems, including other inquiline systems (e.g,. Maguire 1971, Koukouras 1992), host-parasite interactions, and plant-herbivore communities (e.g., Waltz & Whitham 1997), in which colonizing assemblages interacts with living host.
Table 1 -- Summary of proposed experiments, including growing seasons in which each experiment will be conducted. All greenhouse experiments will be replicated in the field at Hawley Bog, while stand-alone field experiments will be conducted at both Hawley and Molly Bogs.
Exp. Location and Date 1 Hawley & Molly Bogs 5/98-10/01 Greenhouse 5/98-10/01 Greenhouse 5/98-10/01 Hawley Bog 5/98-10/01 Hawley & Molly Bogs 1999, 2000 Hawley & Molly Bogs 1999, 2000 I II II Path Model Plant population growth Leaf allocation Leaf allocation Leaf allocation Protocol Demographic monitoring. Response variables Transition probabilities between juveniles, nonreproductive adults, and reproductive adults; seed set. Leaf-level: pitcher-liquid nutrient concentration NO3-N, NH3-N, PO4-P, and Ca) and pH; leaf tissue nutrient content; Pmax of leaves and respiration of inquilines. Whole-plant level: rate of new leaf production; relative proportion of pitchers and phyllodes produced; years to first reproduction and consequent seed set. Inquiline community persistence, measured as survivorship, growth, and % eclosion. Pitcher liquor chemistry (pH, NO3-N, NH3-N, PO4-P, Ca). Inquiline community assembly, measured as colonization rate of the different species, and persistence (as in Experiment 5). Temporal bias in this experiment will be assessed with a parallel set of observations of unmanipulated plants. Prey capture rate (carcasses/pitcher/day) of monospecific and mixed populations of house-flies and fruit-flies. Prey capture rates. Temporal bias in this experiment will be assessed with a network of pitfall traps and sticky traps to monitor composition and abundance of possible prey species.
2 3 4
Soil nutrients (4) Inquiline communities (4) in a repeated-measures, split-plot design. Soil nutrients (4) Pitcher nutrients (8) in a repeated-measures, split-plot design. Pitcher nutrients (8) Soil nutrients (natural, measured) Plant stage (2) in a repeated-measures ANCOVA design. Leaf size (2) Leaf age (3) Inquiline communities (3) in a balanced, factorial design. Leaf size (2) Leaf age (3) in a balanced, factorial design.
Greenhouse 2001 Hawley Bog 2001
Leaf allocation & Inquiline assembly Leaf allocation & Inquiline assembly
Leaf size (2) Leaf age (3) in a balanced, factorial design, stratified by phyllode:pitcher leaf ratio. Leaf size (2) Leaf age (3) in a balanced, factorial design, stratified by phyllode:pitcher leaf ratio.
IMPACT OF THE PROPOSED RESEARCH ON THE EDUCATIONAL INFRASTRUCTURE AT MOUNT HOLYOKE COLLEGE (RUI Impact Statement) The proposed research will have three substantive, positive impacts on undergraduate biology education at Mount Holyoke College. First, this research project will provide opportunities for undergraduate summer research, year-long independent projects leading to senior honors theses, and termtime work-study employment. Four of the proposed experiments (Experiments 5-8) could be done as summer student research projects leading into year-long senior independent projects. Experiments 6 and 8 are well-designed for undergraduate collaborations: one student responsible for the experimental work and the other responsible for independent observation/monitoring protocols designed to account for possible experimental bias. Experiments 1-4 require long-term attention and oversight by a single individual (hence the budget request for continued support for the technician in Ellison's lab at Mount Holyoke), but similarly provide opportunities for summer research collaborations. The long-term nature of Experiments 1-4 will let students build on each other's work, encouraging a sense of continuity among student researchers. In addition, we encourage undergraduates to initiate projects related to but independent of the proposed core research (funding for such projects is available directly to undergraduates through other grants and endowed funds at Mount Holyoke). We note in particular that one undergraduate, Sybil Gotsch, obtained independent funding (in 1996) for her study of germination of S. purpurea seeds that has been submitted for publication, and which led to the development of the germination protocols used for Experiments 2, 3, and 7. Finally, work-study students will be employed to maintain lab cultures of inquilines and prey. All students working on this project will be incorporated into general activities of term-time and summer research programs in Biology, Chemistry, and Mathematics at Mount Holyoke. These include training in "science survival skills" (e.g., Feibelman, 1993) through participation in a 3-day summer workshop (supported by a grant from Howard Hughes Medical Institute), end-of-summer poster and oral presentations, participation in the annual undergraduate science symposium at Mount Holyoke, and attendance at regional and national meetings. Second, this research project will provide opportunities for student participants to develop skills in ecological modeling. During the last three years of the grant, all students involved in these projects annually will spend two weeks during Mount Holyoke's January intersession at the University of Vermont in an intensive short-course taught by the co-PI (Gotelli). The short course will teach students to use EcoSim and MatLab to model community processes. Using the community assembly model developed herein as a base, students will explore mathematical models commonly used in studies of community ecology (Gotelli 1995, Gotelli & Graves 1996). Since there is no modeling course at Mount Holyoke, this short-course will provide a new curricular opportunity for ecology students enrolled at Mount Holyoke. Working at the University of Vermont also will provide Mount Holyoke students with possibilities of working with graduate students and post-docs, role models in short supply at Mount Holyoke. Finally, the greenhouse populations of pitcher plants and the associated infrastructural modifications to the ecology research wing of the Mount Holyoke conservatory will continue to be used by students and faculty well beyond the term of this grant. Prior grants to the PI were used to develop mangrove mesocosms that are now used in introductory biology, a sophomore course in ecology & evolution, and a senior seminar in ecology. Similarly, pitcher plants are ideal model micro-ecosystems that can be used for teaching concepts in areas ranging from plant physiology through community structure. Investments in the basic research projects proposed here will pay off not only in publications by the PIs and their students, but also in longer-term improvements to the undergraduate biology curriculum at Mount Holyoke College. Both Mt. Holyoke and the University of Vermont are dedicated to high-quality undergraduate teaching. Ellison's PFF award was for excellence in teaching, research, and service. Gotelli was recently awarded the Dean's Lecturer for excellence in undergraduate teaching and research.
I. Peer-reviewed publications resulting from prior NSF support to A. M. Ellison A. Mangrove papers (main focus of BSR 91-07195, DEB 92-53743, and DEB 97-41904). Undergraduate co-authors indicated by * Ellison, A. M. & E. J. Farnsworth. 1992. Belizean mangrove-root epibionts: patterns of distribution and abundance, and effects on root growth. Hydrobiologia 247: 87-98. Ellison, A. M. & E. J. Farnsworth. 1993. Seedling survivorship, growth, and response to disturbance in Belizean mangal. American Journal of Botany 80: 1137-1145. Farnsworth, E. J. & A. M. Ellison. 1993. Dynamics of herbivory in Belizean mangal. Journal of Tropical Biology 9: 435-453. Farnsworth, E. J. & A. M. Ellison. 1996a. Scale-dependent spatial and temporal variability in biogeography of mangrove-root epibiont communities. Ecological Monographs 66: 45-66. Murren, C. J.*, & A. M. Ellison. 1996. Effects of habitat, plant size, and floral display on male and female reproductive success of the neotropical orchid Brassavola nodosa. Biotropica 28: 30-41. Farnsworth, E. J. & A. M. Ellison. 1996b. Sun-shade adaptability of the red mangrove, Rhizophora mangle (Rhizophoraceae): changes through ontogeny at several levels of biological organization. American Journal of Botany 83: 1131-1143. Ellison, A. M. & E. J. Farnsworth. 1996a. Spatial and temporal variability in growth of Rhizophora mangle saplings on coral cays: links with variation in insolation, herbivory, and local sedimentation rate. Journal of Ecology 84: 717-731. Ellison, A. M. & E. J. Farnsworth. 1996b. Anthropogenic disturbance to Caribbean mangrove ecosystems: past impacts, present trends, and future predictions. Biotropica 28: 549-565. Ellison, A.M., E. J. Farnsworth, & R.R. Twilley. 1996. Facultative mutualism between red mangroves and rootfouling sponges in Belizean mangal. Ecology 77: 2431-2444. Farnsworth, E. J., A. M. Ellison, & W.-K. Gong. 1996. Elevated CO2 alters anatomy, physiology, growth and reproduction of red mangrove (Rhizophora mangle L.). Oecologia 108: 599-609. Farnsworth, E. J. & A. M. Ellison. 1997a. Global patterns of predispersal seed predation on mangroves and its effects on seedling regeneration. Biotropica 29: 318-330. Farnsworth, E. J. & A. M. Ellison. 1997b. Global conservation ecology of mangrove ecosystems. Ambio 26: 328334. Ellison, A. M. & E. J. Farnsworth. 1997. Simulated sea-level change alters anatomy, physiology, growth, and reproduction of red mangrove (Rhizophora mangle L.). Oecologia (in press). Ellison, A. M. 1998. Wetlands of Central America. To appear in: D.F. Whigham, D. Dykjova, & S. Hejn, editors. Wetlands of the World, volume 2. Murren, C. J.* & A. M. Ellison. 1998. Seed dispersal characteristics of Brassavola nodosa (Orchidaceae). American Journal of Botany (in press). Merkt, R. E.* & A. M. Ellison. 1998. Patterns of morphological variation in the amphi-Atlantic mangrove snail, Littoraria (Littorinopsis) angulifera Lamarck. Malacologia (in review). Ellison, A. M., E. J. Farnsworth, & R. E. Merkt.* 1998. Biogeography and paleoecology of mangrove ecosystems: can invertebrates distinguish between center of origin and vicariance? To be submitted to Journal of Biogeography. B. Additional peer-reviewed publications acknowledging support of BSR 91-07195 or DEB 92-53743 Undergraduate co-authors indicated by * Ellison, A. M. 1993. Exploratory data analysis and graphic display. Pages 14-45 In: S.M. Scheiner and J. Gurevitch, editors. Design and analysis of ecological experiments. Chapman & Hall, New York. Ellison, A. M., J. S. Denslow, B. Loiselle & D. Brens M. 1993. Seed and seedling ecology of neotropical Melastomataceae. Ecology 74: 1733-1749.
Ellison, A. M., K. J. Niklas & S. Shumway. 1993. Xylem vascular anatomy and water transport of Salicornia europaea. Aquatic Botany 45: 325-339. Ellison, A. M., P. M. Dixon, and J. Ngai*. 1994. A null model for neighborhood models of plant competitive interactions. Oikos 71: 225-238. Ellison, A. M. & B. L. Bedford. 1995. Response of a wetland vascular plant community to disturbance: a simulation study. Ecological Applications 5: 109-123. Ellison, A. M. 1996. Bayesian inference for ecological research and environmental decision-making. Ecological Applications 6: 1036-1046. Blackstone, N. M. & A. M. Ellison. 1998. Metazoan development and units of evolution. American Naturalist (in review).
II. Peer-reviewed publications resulting from prior NSF support to N. J. Gotelli
Gotelli, N. J. 1993. Antlion zones: causes of high-density predator aggregations. Ecology 74: 226-237. Albrecht, M. 1995. New records of ant species in Oklahoma, including a South American invader. Proceedings of the Oklahoma Academy of Sciences 75: 21-24. Gotelli, N. J. 1995. A primer of ecology. Sinauer Associates, Sunderland. Gotelli, N. J. 1996. Ant community structure: effects of predatory ant lions. Ecology 77: 630-638. Gotelli, N. J. and G. L. Entsminger. 1996. EcoSim. 1.10. Null models software for ecology. Acquired Intelligence, Inc. Kesey-Bear, Burlington. Gotelli, N. J. and G. R. Graves. 1996. Null models in ecology. Smithsonian Institution Press, Washington, D.C. Gotelli, N. J. 1997. Competition and coexistence of larval ant lions. Ecology 78: 1761-1773. Arnett, A. E., and N. J. Gotelli. 1998. Geographic variation in ant lion body size and heterozygosity. Journal of Biogeography (in review).
III. Literature cited in body of proposal Adamec, L. 1997. Mineral nutrition of carnivorous plants: a review. The Botanical Review 63: 273-299. Addicott, J. F. 1974. Predation and prey community structure: an experimental study of the effect of mosquito larvae on the protozoan communities of pitcher plants. Ecology 55: 475-492. American Public Health Association (APHA). 1985. Standard methods for the examination of water and wastewater, 16th edition. APHA, Washington, D.C. Arber, A. 1941. On the morphology of the pitcher-leaves in Heliamphora, Sarracenia, Darlingtonia, Cephalotus, and Nepenthes. Annals of Botany 5: 563-578. Beaver, R. A. 1983. The communities living in Nepenthes pitcher plants: fauna and food webs. Pages 125-159 in H. Frank and L. P. Lounibos, editors. Phytotelmata: terrestrial plants as hosts for aquatic insect communities. Plexus Press, NJ Bedford, B. L., M. R. Walbridge, and A. Aldous. 1998. Patterns of nutrient availability and plant diversity of temperate North American wetlands. Ecological Applications (in press). Bender, E. A., T. J. Case, and M. E. Gilpin. 1984. Perturbation experiments in community ecology: theory and practice. Ecology 65: 1-13. Bedzki, L. A., and A. M. Ellison. 1997. Population dynamics of Habrotrocha rosa and its contribution to nutrient dynamics in the northern pitcher plant, Sarracenia purpurea. Hydrobiologia (in review). Bradshaw, W. E. 1983. Interaction between the mosquito Wyeomyia smithii, the midge Metriocnemus knabi, and their carnivorous host Sarracenia purpurea. Pages 161-189 in H. Frank and L. P. Lounibos, editors. Phytotelmata: terrestrial plants as hosts for aquatic insect communities. Plexus Press, NJ Bradshaw, W. E., and R. A. Creelman. 1984. Mutualism between the carnivorous purple pitcher plant Sarracenia purpurea and its inhabitants. American Midland Naturalist 112: 294-304.
Bradshaw, W. E., and C. M. Holzapfel. 1992. Reproductive consequences of density-dependent size variation in the pitcher plant mosquito, Wyeomyia smithii. Annals of the Entomological Society of America 85: 274-281. Bridgham, S. D., J. Pastor, J. A. Janssens, C. Chapin, and T. J. Malterer. 1996. Multiple limiting gradients in peatlands: a call for a new paradigm. Wetlands 16: 45-65. Brower, J. H., and A. E. Brower. 1971. Notes on the biology and distribution of moths associated with the pitcher plant in Maine. Proceedings of the Entomological Society of Ontario 101:79-83. Cameron, C. J., G. L. Donald, and C. G. Paterson. 1977. Oxygen - fauna relationships in the pitcher plant Sarracenia purpurea L. with reference to the chironomid Metriocnemus knabi Coq. Canadian Journal of Zoology 55: 2018-2023. Caswell, H. 1986. Life cycle models for plants. Lectures on Mathematics in the Life Sciences 18: 171-233. Chapin, C. T., and J. Pastor. 1995. Nutrient limitation in the northern pitcher plant Sarracenia purpurea. Canadian Journal of Botany 73: 728-734. Christensen, N. L. 1976. The role of carnivory in Sarracenia flava L. with regard to specific nutrient deficiencies. The Journal of the Elisha Mitchell Society 92: 144-147. Connell, J. H. and R. O. Slatyer. 1977. Mechanisms of succession in natural communities and their role in community stability and organization. The American Naturalist 111: 1119-1144. Connor, E. F. and D. Simberloff. 1979. The assembly of species communities: chance or competition? Ecology 60: 1132-1140. Cresswell, J. 1991. Capture rates and composition of insect prey of the pitcher plant Sarracenia purpurea. American Midland Naturalist 125: 1-8. Dean, T. A. 1981. Structural aspects of sessile invertebrates as organizing forces in an estuarine fouling community. Journal of Experimental Marine Biology and Ecology 53: 163-180. Diamond, J. M. 1975. Assembly of species communities. Pages 342-444 In M. L. Cody and J. M. Diamond, editors. Ecology and evolution of communities. Harvard University Press, Cambridge. Diamond, J. M. and M. E. Gilpin. 1982. Examination of the "null" model of Connor and Simberloff for species co-occurrences on islands. Oecologia 52: 64-74. Diamond, J. M. 1986. Effects of larval retreats of the caddisfly Cheumatopsyche on macroinvertebrate colonization in piedmont, USA streams. Oikos 47: 13-18. Drake, J. A. 1990. Communities as assembled structures: do rules govern pattern? Trends in Ecology and Evolution 5: 159-164. Drake, J. A. 1991. Community-assembly mechanics and the structure of an experimental species ensemble. The American Naturalist 137: 1-26. Drake, J. A., T. E. Flum, G. J. Witteman, T. Voskuil, A. M. Hoylman, C. Creson, D. A. Kenny, G. R. Huxel, C. S. Larue, and J. R. Duncan. 1993. The construction and assembly of an ecological landscape. Journal of Animal Ecology 62: 117-130. Ellsworth, D.S., and P. B. Reich. 1992. Leaf mass per area, nitrogen content, and photosynthetic carbon gain in Acer saccharum seedlings in contrasting forest light environments. Functional Ecology 6: 423-435. Ejsmont-Karabin, J. 1984. Phosphorus and nitrogen excretion by lake zooplankton (rotifers and crustaceans) in relationship to individual body weights of the animals, ambient temperature and presence or absence of food. Ekologia Polska 32: 3-42. Evans, J. R. 1989. Photosynthesis and nitrogen relationships in leaves of C3 plants. Oecologia 78: 9-19. Feibelman, P. J. 1993. A Ph.D. is not enough! A guide to survival in science. Addison-Wesley, Reading, Massachusetts. Field, C., and H. A. Mooney. 1986. The photosynthesis-nitrogen relationship in wild plants. Pages 25-55 in T. Givnish, editor. On the economy of plant form and function. Cambridge University Press, Cambridge. Fish, D. Phytotelmata: flora and fauna. Pages 1-27 in H. Frank and L. P. Lounibos, editors. Phytotelmata: terrestrial plants as hosts for aquatic insect communities. Plexus Press, NJ. Fish, D., and D. W. Hall. 1978. Succession and stratification of aquatic insects inhabiting the leaves of the insectivorous pitcher plant Sarracenia purpurea. American Midland Naturalist 99: 172-183. Forsyth, A. B., and R. J. K. Robertson. 1975. K reproductive strategy and larval behavior of the pitcher plant sarcophagid fly, Blaesoxipha fletcheri. Canadian Journal of Zoology 53: 174-179.
Fresnius, W., K. E. Quention, and W. Schneider (editors). 1988. Water analysis: a practical guide to physicochemical, chemical and microbiological water examination and quality assurance. Springer-Verlag, Berlin. Gilpin, M. E., M. P. Carpenter and M. J. Pomerantz. 1986. The assembly of a laboratory community: multispecies competition in Drosophila. Pages 33-40 in J. M. Diamond and T. J. Case, editors. Community ecology. Harper and Row, New York. Givnish, T. J., E. L. Burkhardt, R. E. Happel, and J. D. Weintraub. 1984. Carnivory in the bromeliad Brocchinia reducta, with a cost/ benefit model for the general restriction of carnivorous plants to sunny, moist nutrient-poor habitats. The American Naturalist 124: 479-497. Givnish, T. J. 1989. Ecology and evolution of carnivorous plants. Pages 243-290 in W. G. Abramson, editor. Plant-animal interactions. McGraw-Hill, Toronto. Gotelli, N. J. 1991. Demographic models for Leptogargia virgulata, a shallow-water gorgonian. Ecology 72: 457468. Gotelli, N. J. 1995. A primer of ecology. Sinauer Associates, Sunderland, Massachusetts. Gotelli, N. J., and G. R. Graves. 1996. Null models in ecology. Smithsonian Institution Press, Washington, D. C. Gotelli, N. J., N. J. Buckley, and J. A. Wiens. 1997. Co-occurrence of Australian land birds: Diamond's assembly rules revisited. Oikos 80: 311-324. Gotsch, S. G., and A. M. Ellison. 1997. Seed germination of the northern pitcher-plant, Sarracenia purpurea. Northeastern Naturalist (in review). Heard, S. B. 1994a. Imperfect oviposition decisions by the pitcher plant mosquito (Wyeomyia smithii). Evolutionary Ecology 8: 493-502. Heard, S. B. 1994b. Pitcher plant midges and mosquitoes: a processing chain commensalism. Ecology 75:16471660. Hepburn, J. S., E. Q. S. John, and F. M. Jones. 1920. The absorption of nutrients and allied phenomena in the pitchers of the Sarraceniaceae. Journal of the Franklin Institute 189: 147-184. Heslop-Harrison, Y. 1978. Carnivorous plants. Scientific American 238(2): 104-115. Istock, C.A., K. J. Vavra, and H. Zimmer. 1976. Ecology and evolution of the pitcher-plant mosquito. 3. Resource tracking by a natural population. Evolution 30: 548-557. Joel, D. M., and H. S. Heide-Jrgensen. 1985. Ultrastructure and development of the pitcher epithelium of Sarracenia. Israel Journal of Botany 34: 331-349. Joel, D. M., and S. Gepstein. 1985. Chloroplasts in the epidermis of Sarracenia (the American pitcher plant) and their possible role in carnivory -- an immunocytochemical approach. Physiologia Plantarum 63: 71-75. Jones, C. G., J. H. Lawton, and M. Shachak. 1997. Positive and negative effects of organisms as physical ecosystem engineers. Ecology 78: 1946-1957. Judd, W. W. 1959. Studies of the Byron Bog in southwestern Ontario. X. Inquilines and victims of the pitcher plant, Sarracenia purpurea L. Canadian Entomologist 91: 171-180. Kingsolver, J. G. 1981. The effects of environmental uncertainty on morphological design and fluid balance in Sarracenia purpurea L. Oecologia 48: 364-370. Koukouras, A., A. Russo, E. Voultsiadou-Koukoura, C. Dounas, and C. Chintiroglou. 1992. Relationship of sponge macrofauna with the morphology of their hosts in the North Aegean Sea. Internationale Revue Der Gestamen Hydrobiologie 77: 609-619. Lawler, S. P. 1993. Direct and indirect effects in microcosm communities of protists. Oecologia 93: 184-190. Lttge, U. 1983. Ecophysiology of carnivorous plants. Pages 489-517 in O. L. Lange, P. S. Nobel, C. B. Osmond, and H. Ziegler, editors. Physiological Plant Ecology III (Encyclopedia of Plant Physiology, volume 12C). Springer-Verlag, New York. Ma, T.S., and R. C. Rittner. 1979. Modern organic elemental analysis. Marcel-Dekker, New York. Maguire, B. J. 1971. Phytotelmata: biota and community structure in plant held waters. Annual Reviews of Ecology and Systematics 2: 439-464. Mandossian, A. J. 1966. Variations in the leaf of Sarracenia purpurea (pitcher plant). The Michigan Botanist 5: 26-35. MathSoft. 1997. S-Plus User's Guide. Data Analysis Products Division, MathSoft, Seattle, Washington.
Miller, T. C., D. Cassill, C. Johnson, C. Kindell, J. Lepis, D. McInnes, T. Bevis, D. Mehlman, and B. Richard. 1994. Intraspecific and interspecific competition of Wyeomyia smithii (Coq.) (Culicidae) in a pitcher plant communities. American Midland Naturalist 131: 136-145. Mogi, M., and H. S. Yong. 1992. Aquatic arthropod communities in Nepenthes pitchers: the role of niche differentiation, aggregation, predation and competition in community organization. Oecologia 90: 182184. Naeem, S. 1988. Resource heterogeneity fosters coexistence of a mite a midge in pitcher plants. Ecological Monographs 58: 215-227. Paterson, C. G. 1971. Overwintering ecology of the aquatic fauna associated with the pitcher plant, Sarracenia purpurea L. Canadian Journal of Zoology 49: 1455-1459. Paterson, C. G., and C. J. Cameron. 1982. Seasonal dynamics and ecological strategies of the pitcher plant chironomid Metriocnemus knabi (Diptera, Chironomidae) in southeast New Brunswick, Canada. Canadian Journal of Zoology 60: 3075-3083. Plummer, G., and J. B. Kethley. 1964. Foliar absorption of amino acids, peptides, and other nutrients by the pitcher plant, Sarracenia flava. Botanical Gazette 125: 245-260. Prankevicius, A. B., and D. M. Cameron. 1991. Bacterial dinitrogen fixation in the leaf of the northern pitcher plant (Sarracenia purpurea). Canadian Journal of Botany 69: 2296-2298. Pringle, C. M. 1985. Effects of chironomid (Insecta: Diptera) tube-building activities on stream diatom communities. Journal of Phycology 21: 185-194. Ratsirarson, J., and J. A. Silander. 1996. Structure and dynamics in Nepenthes madagascariensis pitcher plant microcommunities. Biotropica 28: 218-227. Richardson, C. J. 1985. Mechanisms controlling phosphorus retention capacity in freshwater wetlands. Science 228: 1424-1427. Richardson, C. J., and P. E. Marshall. 1986. Processes controlling movement, storage, and export of phosphorus in a fen peatland. Ecological Monographs 56: 279-302. Samuels, C. L. and J. A. Drake. 1997. Divergent perspectives on community convergence. Trends in Ecology and Evolution 12: 427-432. Schwaegerle, K. E. 1983. Population growth of the pitcher plant, Sarracenia purpurea L., at Cranberry Bog, Licking County, Ohio. Ohio Journal of Science 83: 19-22. Sommer, U. 1991. Convergent succession of phytoplankton in microcosms with different innoculum species composition. Oecologia 87: 171-179. Stone, L., T. Dayan, and D. Simberloff. 1996. Community-wide assembly patterns unmasked: the importance of species' differing geographical ranges. American Naturalist 146: 997-1015. Tanner, J. E., T. P. Hughes, and J. H. Connell. 1996. The role of history in community dynamics: a modeling approach. Ecology 77: 108-117. Usher, M. B. 1979. Markovian approaches to ecological succession. Journal of Animal Ecology 48: 413-426. Verhoeven, J. T. A., W. Koerselman, and A. F. M. Meuleman. 1996. Nitrogen- or phosphorus-limited growth in herbaceous, wet vegetation: relations with atmospheric inputs and management regimes. Trends in Ecology and Evolution 11: 494-497. Waltz, A. M., and T. G. Whitham. 1997. Plant development affects arthropod communities: opposing impacts of species removal. Ecology 78: 2133-2144. Weiher, E., and P. A. Keddy. 1995. The assembly of experimental wetland plant communities. Oikos 73: 323335. Weiss, T. E. J. 1980. The effects of fire and nutrient availability on the pitcher plant Sarracenia flava L. Ph.D. dissertation, University of Georgia, Athens. Wen, Y. N., and R. H. Peters. 1994. Empirical models of phosphorus and nitrogen excretion rates by zooplankton. Limnology and Oceanography 39: 1669-1679. Wiens, J. A. 1980. Concluding comments: are bird communities real? Acta XVII Congressus Internationalis Ornithologici 1088-1089. Wilson, J. B. 1995. Null models for assembly rules: the Jack Horner effect is more insidious than the Narcissus effect. Oikos 72: 139-144.
Wilson, J. B. and S. H. Roxburgh. 1994. A demonstration of guild-based assembly rules for a plant community, and determination of intrinsic guilds. Oikos 69: 267-276. Wilson, J. B., R. B. Allen, and W. G. Lee. 1995. An assembly rule in the ground and herbaceous strata of a New Zealand rain forest. Functional Ecology 9: 61-64. Williams, R. M. 1966. Utilization of animal protein by the pitcher plant, Sarracenia purpurea. The Michigan Botanist 5: 14-17. Wolfe, L. M. 1981. Feeding behavior of a plant: differential prey capture in old and new leaves of the pitcher plant (Sarracenia purpurea). American Midland Naturalist 106: 352-359.
BIOGRAPHICAL SKETCHES AARON M. ELLISON MARJORIE FISHER ASSOCIATE PROFESSOR OF ENVIRONMENTAL STUDIES Department of Biological Sciences and Program in Environmental Studies Mount Holyoke College, South Hadley, Massachusetts, 01075-6418, USA Tel: 413/538-2110; FAX: 413/538-2548; Electronic mail: firstname.lastname@example.org Education 1982 -- B.A. (East Asian studies/Asian philosophy), Yale University, New Haven, Connecticut. 1986 -- Ph.D. (Ecology and evolutionary biology), Brown University, Providence, Rhode Island. Recent Positions Held September 1990 - June 1996 Assistant Professor, Department of Biological Sciences, Mount Holyoke College. July 1993 - June 1996 Marjorie Fisher Assistant Professor of Environmental Studies, Mount Holyoke College. November 1993 - present Member, Five College Graduate Faculty, Department of Forestry and Wood Technology, University of Massachusetts, Amherst, Massachusetts. July 1996 - present Marjorie Fisher Associate Professor of Environmental Studies and Associate Professor of Biological Sciences, Mount Holyoke College. Recent Grants May 1991 National Science Foundation, "Animal-plant interactions in mangrove communities," BSR-91-07195, 3-1/2 years (12/91-5/95), $162,000. May 1992 National Science Foundation, Presidential Faculty Fellow Award, "Marine Environmental Ecology: Teaching, Research and Conservation," DEB-92-53743, 5 years (9/92-9/97 + no-cost extension to 9/98), $500,000. May 1996 Howard Hughes Medical Institute, "Undergraduate biology curriculum enhancement at Mount Holyoke College," HHMI 71196-505002, 4 years (8/96-8/00), $900,000. April 1997 National Science Foundation, "REU Supplement to DEB-92-53743," DEB-9741904, 3 months (6/97-8/97), $5,000. Editorial service 1994-1999 Board of Editors, American Journal of Botany 1998-2001 Board of Editors, Ecology & Ecological Monographs Relevant Publications (undergraduate co-author indicated by *) Ellison, A. M. 1991. Life-history and feeding behavior of case-bearing moths (Lepidoptera: Coleophoridae) in a New England salt marsh. Environmental Entomology 20: 857-864. Farnsworth, E. J. & A. M. Ellison. 1996. Scale-dependent spatial and temporal variability in biogeography of mangrove-root epibiont communities. Ecological Monographs 66: 4566.
Ellison, A.M., E. J. Farnsworth, & R.R. Twilley. 1996. Facultative mutualism between red mangroves and root-fouling sponges in Belizean mangal. Ecology 77: 2431-2444. Bedzki, L. A. & A. M. Ellison. 1997. Population dynamics of Habrotrocha rosa and its contribution
to nutrient dynamics in the northern pitcher plant, Sarracenia purpurea. Hydrobiologia (in review).
Gotsch, S. G.* & A. M. Ellison. 1997. Seed germination of the northern pitcher plant, Sarracenia purpurea L. Northeastern Naturalist (in review). Five Other Significant Publications Ellison, A. M. 1996. Bayesian inference for ecological research and environmental decisionmaking. Ecological Applications 6: 1036-1046. Ellison, A. M. & E. J. Farnsworth. 1996. Anthropogenic disturbance to Caribbean mangrove ecosystems: past impacts, present trends, and future predictions. Biotropica 28: 549-565. Farnsworth, E. J., A. M. Ellison, & W.-K. Gong. 1996. Elevated CO2 alters anatomy, physiology, growth and reproduction of red mangrove (Rhizophora mangle L.). Oecologia 108: 599-609. Farnsworth, E. J. & A. M. Ellison. 1997. Global conservation ecology of mangrove ecosystems. Ambio 26: 328-334. Ellison, A. M. & E. J. Farnsworth. 1997. Simulated sea-level change alters anatomy, physiology, growth, and reproduction of red mangrove (Rhizophora mangle L.). Oecologia (in press). Recent Collaborators Barbara L. Bedford, Neil Blackstone, Leszek Bedzki, Jan Conn, Humberto Daz, Philip M. Dixon, Elizabeth J. Farnsworth, Gong-Wooi Khoon, Nick Gotelli, Rachel E. Merkt, Thomas L. Millette, Barid B. Mukherjee, Courtney J. Murren, Jeannie Ngai, Karl J. Niklas, Scott Shumway, Robert R. Twilley, Graduate Students Fabian Menalled (member of Ph.D. committee) Avril de la Cretaz (member of Ph.D. committee) Suzette Stephens (member of Ph.D. committee) Dierdre Joy (member of Ph.D. committee) Gregg Moore (member of Ph.D. committee) Graduate and Post-doctoral Advisors Mark D. Bertness (Ph.D. advisor) Barbara L. Bedford (Post-doc advisor) Karl J. Niklas (Post-doc advisor) Deborah Rabinowitz (Post-doc advisor; deceased) Julie S. Denslow (Post-doc advisor)
NICHOLAS J. GOTELLI ASSOCIATE PROFESSOR Department of Biology University of Vermont Burlington, VT 05405-0086 (802) 656-0450 (Office) (802) 656-0451 (Lab) (802) 656-2914 (FAX) email@example.com (e-mail) Social Security #: 559-17-0395 Date of Birth: 27 June 1959 Spouse: Maryanne E. Kampmann
Education Florida State University, 1982-1985; Ph.D. December 1985 Florida State University, 1980-1982; M.S. June 1982 University of California, Berkeley, 1976-1980, B.S. May 1980, Phi Beta Kappa Post-graduate appointments 1995 - present. Associate Professor, Department of Biology, University of Vermont 1992 - 1994. Assistant Professor, Department of Biology, University of Vermont 1988 - 1992. Assistant Professor, Department of Zoology, University of Oklahoma 1987 - 1988. Post-Doctoral Associate, Department of Biology, Colorado State University 1985 - 1987. Lecturer, Department of Organismic, Evolutionary Biology, Harvard University Honors 1993. Fulbright Foundation. The evolution of altered host behavior. Research award, University of Oxford, Great Britain. 1997. Dean's Lecturer, College of Arts and Sciences, University of Vermont. Awarded for excellence in undergraduate teaching and scholarship. Funding 1997-1999. National Science Foundation. Behavioral strategies of sit-and-wait foragers: models of ant lion foraging. $110,000. Co-PI N. Buckley. 1997-1998. National Science Foundation. DEB-9615708. Doctoral Dissertation Improvement Grant for Amy Arnett. Geographic variation in life history traits of the ant lion, Myrmeleon immaculatus. $8,000. 1996-1997. National Science Foundation. BIR-9612109. EcoSim: A Proposal for Null Models Software. $50,000. 1992 - 1995. National Science Foundation. DEB 91-18962. Ant-lion Zones: Consequences of high-density predator aggregations. $144,000. 1989 - 1991. National Science Foundation. BSR 88-17495. The evolution of altered behaviors in parasitized animals: a cockroach-acanthocephalan model. Co-PI with J. Moore. $81,000.
Editorial Service 1992 - present. Board of Editors, Biodiversity Letters 1994 - 1997. Board of Editors, The American Naturalist Relevant Publications Gotelli, N. J., N. J. Buckley, and J. A. Wiens. 1997. Co-occurrence of Australian land birds: Diamond's assembly rules revisited. Oikos 80: 311-324. Gotelli, N. J. 1997. Competition and coexistence of larval ant lions. Ecology 78: 1761-1773. Gotelli, N. J. and G. R. Graves. 1996. Null Models in Ecology. Smithsonian Institution Press, Washington, D.C. Graves, G. R. and N. J. Gotelli. 1993. Assembly of avian mixed species flocks in Amazonia. Proceedings of the National Academy of Sciences, U.S.A. 90: 1388-1391. Gotelli, N. J. 1991. Demographic models for Leptogorgia virgulata, a shallow-water gorgonian. Ecology 72: 457-467. Five other significant publications Gotelli, N. J. 1996. Ant community structure: effects of predatory ant lions. Ecology 77: 630-638. Gotelli, N. J. 1995. A Primer of Ecology. Sinauer Associates, Inc., Sunderland, MA. Gotelli, N. J. 1993. Antlion zones: causes of high-density predator aggregations. Ecology 74: 226-237. Gotelli, N. J. 1991. Metapopulation models: the propagule rain, the rescue effect, and the core-satellite hypothesis. The American Naturalist 138: 768-776. Gotelli, N. J. and W. H. Bossert. 1991. Ecological character displacement in a variable environment. Theoretical Population Biology 39: 49-62. Recent collaborators Neil Buckley, Gary Entsminger, John Wiens, Chris Taylor, Aaron Ellison Graduate students and post-doctoral advisees Neil Buckley (Current post-doc), Marc Albrecht (Graduate student, OU), Amy Arnett (Graduate student, UVM), Jerald Johnson (Graduate student, UVM), Declan McCabe (Graduate student, UVM). Graduate and post-doctoral advisors D. S. Simberloff (Ph.D. advisor) J. K. Moore (Post-doc advisor)
BUDGET JUSTIFICATION Mount Holyoke College This is a five-year grant because four years is the minimum time necessary for pitcher plants in our experiments to reach reproductive maturity, flower, and set seed. While no experiments will be conducted during the fifth year of support, it will be used to complete model calibration and finalize manuscripts of the experiments that ran for four years. The PI requests 1 month of summer salary during the period of the award. Funding is requested to support a half-time technician in the PI's lab ($13,000 per year). This individual is experienced in aquatic chemistry, nutrient cycling, rotifer biology, and rearing inquilines. He will be responsible for water nutrient analysis, inquiline colony maintenance, greenhouse plant maintenance and experimental oversight, and additional supervision of work-study students. Most importantly, the technician provides continuity in sampling and experimental maintenance, and enables the PI to better balance his teaching and research obligations. Salaries for the technician and the PI increase at 3%/year. Three undergraduates at Mt. Holyoke will be supported by the grant during each summer field season, and two undergraduate work-study students will be supported during academic years. Fringe benefits are currently 28% for the technician, and 9% for the PI's summer salary and for undergraduate salaries and stipends. Travel funds are requested for PI to travel to UVM ($200 per year), to travel to national meetings in years 3-5 of the grant ($1,000 per year), and for mileage between Mount Holyoke College and Hawley Bog ($500 per year for an estimated 12 trips @109 miles round trip). `Participant support costs' support undergraduate summer housing at Mount Holyoke (3 students/year @ $900/summer) and will fund the travel and lodging of three Mount Holyoke undergraduates who will spend two weeks each at the University of Vermont taking a short-course in ecological modeling ($2,750 per year in years 3-5). Disposable supplies include soil and potting materials ($1,000 per year), bird bands for labeling plants ($1,000 per year), buffers and chemicals for nutrient experiments ($1,000 per year), media and supplies for rearing inquilines ($1,000 per year), and polyester chiffon for pitcher bags in years 2 and 3 ($500 per year). Mount Holyoke's indirect cost rate is 64.8% on total salaries and wages.
BUDGET JUSTIFICATION University of Vermont This is a five-year grant because four years is the minimum time necessary for pitcher plants in our experiments to reach reproductive maturity, flower, and set seed. While no experiments will be conducted during the fifth year of support, it will be used to complete model calibration and finalize manuscripts of the experiments that ran for four years. The PI requests 1-month of summer salary during the period of the award, with annual 3% increases. Travel funds are requested for the PI to travel to Mt. Holyoke ($200 per year), to travel to national meetings in years 3-5 of the grant ($1,000 per year), and weekly reimbursement for mileage between the University of Vermont and Molly Bog ($250 per year for an estimated 12 trips @ 50 miles round trip). The only equipment request is for a new IBM computer for the modeling component of the grant ($5,000). All of the computers in the PI's lab are now heavily used for simulation modeling and data entry on other projects. Nutrient analyses of plant material (950 samples per year) will be conducted at the University of Vermont's Environmental and Agricultural Testing Laboratory, at a cost of $20 per sample.
CURRENT AND PENDING SUPPORT Investigator: Aaron M. Ellison Support: Current Project Title: Mount Holyoke Faculty Fellowship: Structure and Function of Wetland Ecosystems Source of Support: Mount Holyoke College Total Award Amount: $12,000 Award Period: July 1997 - June 1998 Location of Project: Mount Holyoke College Person-months Committed to this Project: 2 months (Calendar) Support: Current Project Title: Presidential Faculty Fellow: Marine Environmental Ecology: Teaching, Research and Conservation Source of Support: NSF (Award number DEB-92-53743; REU supplement DEB-97-41904) Total Award Amount: $505,000 (includes $5,000 REU supplement) Award Period: September 1992-August 1997 (no-cost extension to August 1998) Location of Project: Mount Holyoke College and Belize, Central America Person-months Committed to this Project: 1 month (Calendar) Support: Current Project Title: Undergraduate Biology Curriculum Enhancement Program Source of Support: Howard Hughes Medical Institute (Award number HHMI 71196-505002) Total Award Amount: $900,000 Award Period: August 1996-August 2000 Location of Project: Mount Holyoke College Person-months Committed to this Project: 2 months (Calendar) Support: Pending (this proposal) Project Title: RUI: Inquiline communities in changeable pitchers: do nutrients link community assembly to dynamic habitats? Source of Support: NSF Total Award Amount: $345,951 Award Period: June 1998 - May 2003 Location of Project: Mount Holyoke College Person-months Committed to this Project: 3 months (Calendar)
Investigator: Nicholas J. Gotelli Support: Current Project Title: Behavioral strategies of sit-and-wait foragers: models of ant lion foraging Source of Support: NSF (Award number DEB-96-15708) Total Award Amount: $110,00 (Co-PI: N. Buckley) Award Period: December 1997 - December 1999 Location of Project: University of Vermont Person-months Committed to this Project: 1 month (Calendar) Support: Current Project Title: Doctoral Dissertation Improvement Grant for Amy Arnett Source of Support: NSF (Award number DEB-97-01122) Total Award Amount: $8,000 Award Period: July 1997 - June 1998 Location of Project: University of Vermont Person-months Committed to this Project: 1 month (Calendar) Support: Pending Project Title: EcoSim: A proposal for null models software. Source of Support: NSF (Proposal number DBI-97-25930) Total Award Amount: $249,940 Award Period: January 1998 - January 2001 Location of Project: University of Vermont Person-months Committed to this Project: 1 month (Calendar) Support: Pending Project Title: Doctoral Dissertation Improvement Grant for Jerry Johnson: Life history evolution in the fish Brachyraphis rhadophora: effects of predation and phylogenetic history Source of Support: NSF (Proposal number DEB-98-00868) Total Award Amount: $10,021 Award Period: April 1998 - April 2000 Location of Project: University of Vermont Person-months Committed to this Project: 0.5 month (Calendar) Support: Pending Project Title: Measuring indirect effects in stream invertebrate communities: quantifying the roles of species interactions, disturbance, and top-down/bottom-up effects. Source of Support: NSF Total Award Amount: $450,000 (Co-PI, James P. Hoffman) Award Period: June 1998 - May 2002 Location of Project: University of Vermont Person-months Committed to this Project: 1 month (Calendar)
Investigator: Nicholas J. Gotelli (continued) Support: Pending (this proposal) Project Title: Inquiline communities in changeable pitchers: do nutrients link community assembly to dynamic habitats? Source of Support: NSF Total Award Amount: $151,220 Award Period: June 1998 - May 2003 Location of Project: University of Vermont & Mount Holyoke College Person-months Committed to this Project: 1 month (Calendar)
FACILITIES, EQUIPMENT, AND OTHER RESOURCES Mt. Holyoke contains excellent facilities for carrying out this research, including a 1,000 ft2 climatecontrolled wing of the College greenhouse complex that will be dedicated for rearing pitcher plants. Through previous NSF funding (BSR-91-07195 and DEB-92-53743), Ellison has purchased substantial capital equipment (Pentium computers, SRI field-portable gas chromatograph, Li-Cor 6200 IRGA, Willd zoom dissecting microscope, Topcon autolevel, Trimble GPS, Orion 290A ph/mV meter and electrodes for pH, redox, NO3-N, NH3-N, Ca, and S, flatbed and slide scanners, Delta-T data logger) that will be used in this project. Additional equipment available for this research at Mount Holyoke includes: Spectronics digital spectrophotometer; Li-Cor LI-3000 desktop leaf area meter; CID portable leaf area meter; convection drying oven; two Li-Cor 1000 data loggers; 6 Li-Cor quantum sensors; 6 Campbell soil temperature probes; 6 Campbell relative humidity sensors; and rain gauges. Two custom cuvettes for the Li-Cor 6200 (8-L and 4-L) already have been built for this research. A reverse-osmosis system to supply pure water (125 L/day), required for pitcher plant culture, will be installed in the greenhouse in February 1998. Machine shop personnel time and facilities are provided at no cost; materials are billed at cost. Hawley Bog and Molly Bog are both on University-owned land. Permits for work at Hawley Bog are in hand, and for Molly Bog are currently being obtained. Teaching computers and classroom space at the University of Vermont will be available for the three undergraduates taking the modeling course, and Gotelli can accommodate this additional teaching load in his schedule. State-of-the-art facilities for nutrient analysis are available at the Agricultural and Environmental Testing Laboratory of the University of Vermont. Nutrient analysis will be carried out by Don Ross, the Director of the Laboratory.