ANT 154B Course notes- Lecture _15

ANT 154B Course notes- Lecture _15 - ANT 154BN Course notes...

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Unformatted text preview: ANT 154BN Course notes Lecture #15: Biogeography and diversity: comparing communities 24 February 2011 Key terms and concepts are indicated in blue Outline 1. Explaining differences among primate communities 2. Patterns in diversity 1. Explaining differences among primate communities Review: Summary of general patterns that require explanation: Comparing primate communities Madagascar: abundance 502 of nocturnal, solitary, 3 folivorous species 2 ￿. ɢ. ￿ʟ￿￿ɢʟ￿ ￿ɴ￿ ￿. ￿. ʀ￿￿￿ Asia: low species diversity; few small species; many suspensory species Factor 2 (25%) Table 2 1 0 –1 –2 –1 0 1 2 3 –3 America: lack of Factor 1 (28%) folivorous,resolitary polygons outlining the ‘‘ecological space’’ of the first twAfrica:prabundance of Figu 6. Superimposed o factors of the incipal components analysis occupied by each of the eight primate communities. (——), South America; (– – –), Asia - -), Mada scar; (· · ·), species; small; (-bodygasizesAfrica. large frugivores –2 Four measures of dispersion among individual species comprising each of the eight primate communities Taxonomic distance (two factors) 1·34 1·36 1·25 1·29 1·18 1·16 Taxonomic distance (all variables) 0·612 0·620 0·466 0·540 0·671 0·614 Thursday, February 25, 2010 Community Ranomafana Morondava Area of polygon 491 460 432 629 577 598 Centroid distance 1·38 1·35 1·23 1·24 1·16 1·14 4 Raleig allen 149 0·79 0·8 0·408 Why are primate communities in eachhvbiogeographic3 region so distinct? Manu 149 0·72 0·68 0·471 Kuala Lompat Ketambe Kibale Tai 1. Differences in forests leapers an l v ous o d • Few primate folivores in Americaudemthre asnmaPlhafanurniococrupy–nfrgusgoivmerosuosrtaorfbonrteearlmqeudaiatreupeodsist,iowi.th onlaygaascfaerwsttaanxdas, notably E l u d e, i i p n Mad Hypothesis: extreme seasonalityheinerAmerica Madainr forests? any consideration of t div sity of primates on 1. Differences gasca must acknowledge the vast -> highly synchronous production of leaves and fruit out in its abundance of folivores and folivore–frugivores, a phenomenon noted in many other discussions of this radiation (e.g., Tattersall, 1982; Terborgh & van Schaik, 1987). However, Few primate folivores in America: logic -> inability to fallback on leaves during periods of fruit scarcity Leaves Fruit ~ leaf availability fruit availability Prohibits falling back on leaves ANT 154B Lecture #15 course notes Few primate folivores in America: initial hypothesis page 2 of 7 1. Differences in forests? Few primate folivores in America: alternative hypothesis alternative hypothesis: body size constraints? • body size constraints? Thursday, February 25, 2010 Terborgh & van Schaik (1987) 9 1. Differences in forests? • Few frugivores in Madagascar ursday, February 25, 2010 Hypothesis: Few frugivores in Madagascar few plants that produce fleshy “primate” fruits? 11 • Madagascan fruits of low quality? Ganzhorn et al. 2009 America Madagascar fruits Thursday, February 25, 2010 America Madagascar other plant parts 14 ANT 154B Lecture #15 course notes • Few insectivores in Asia Hypothesis: few understory insects in Asia page 3 of 7 – forests exceptionally tall, relatively open understory? – less productive soils, therefore fewer young leaves for insects to feed on? • Low primate species richness (and abundance) in Asia Hypothesis: generally low productivity in Asian forests Dipterocarps • Lack of small-bodied species in Asia Hypothesis: inability to survive intense periods of resource scarcity? 2. Differences in competitor sets? • Few primate folivores in South America Hypothesis: competition with sloths? competition with leaf cutter ants? • No gum/exudate feeding primates in Southeast Asia Hypothesis: competition with pygmy squirrels? 3. Historical/biogeographical contingencies? Historical/biogeographical accidents Adaptive potential differs among radiations Recent extinctions Few primate folivores in America: alternative hypothesis • sensory constraints ANT 154B Lecture #15 course notes sensory constraints (Heymann 2001) page 4 of 7 - most South American primates (except Alouatta) lack color vision 3. Historical/biogeographical contingencies? Few primate folivores in America: alternative hypotheses • sensory constraints - most South American primates (except Alouatta) lack color vision Yellow-blue axis Dominy & Lucas (2001) Thursday, February 25, 2010 eaten 26 blueyellow axis Red-green axis Dominy & Lucas (2001) Thursday, February 25, 2010 27 probably a combination of ecological and historical factors Diversity indices depend on both species richness and evenness 2. Patterns in diversity Recall: vs. Less diverse for a given richness, diversity increases with evenness More diverse vs. Temporal variation for a given evenness, diversity increases with richness ANT 154B Lecture #15 course notes Species richness changes over time page 5 of 7 Proportion of Species 100 80 60 40 20 0 Early Miocene Pliocene Monkeys Apes Knoll 1984 first true primates (57-34 mya) Thursday, February 25, 2010 33 Spatial variation Species-area curves Additional habitat or ecosystem types increase species richness The Diversity and Conservation of Papua’s Ecosystems / 759 Figure 5.1.4. SchematiPrimatem of specrichnesserelated cosystem diversity. The c diagra species ies richn ss and e to latitude graph shows species-area cur ves for two landscapes. Landscape 1 (solid line) is stem ty Some other broad trends comprised of a single ecosyEquator pe (A). As more area is sampled the total number of species recorded increases, but slope decreases as an increasing proportion of the total species richness of ecosystem A is recorded. Landscape 2 Latitude (dashed line) is comprised of three ecosystem types (A, B, C). The species-area cur ves for the two landscapes are equivalent as long as sampling is confined to ecosystem A. However, as sampling begins in ecosystem B the species-area cur ve in Landscape 2 increases sharply as many new species are recorded in this new ecosystem type. Sampling of ecosystem C results in another rapid increase in total species richness in Landscape 2. This schematic shows that for any sampling area (e.g., a ) species richness is higher in landscapes containing multiple ecosystem types than in landscapes comprised of a single ecosystem type (e.g., s2 s1). As is the case in many subjects within ecology and conservation biology, the more we learn about ecosystems the more we realize how connected and interdependent they are. As noted above, classification of ecosystems into discrete ‘‘types’’ masks African primates, Eeley & Lawes 1999 the facThursday, Februarye are many important interactions among them. For example, 43 t that ther 25, 2010 seagrass ecosystems provide an important functional link and buffer between reefs and mangrove ecosystems (Chapters 5.3 and 5.4) and forest ecosystems provide Primate ANT 154B Lecture #15 course notes species richness related to latitude page 6 of 7 Equator American primates, Eeley & Lawes 1999 Thursday, February 25, 2010 44 Rapoport’s Rule: Species found near the equator have narrower geographic ranges Africa: Rapaport’s Rule Equator Rapoport’s Rule Equator America: Species found near the equator have narrower geographic ranges Rainfall and primate species richness Species Lawes near African primates, Eeley & found1999 45 Rainfall and primate species richness Thursday, February 25, 2010 the equator have narrower geographic ranges American primates, Eeley & Lawes 1999 Thursday, February 25, 2010 46 ANT 154B page 7 o Primate Rainfall andLecture #15 course notes primate species richness species richnessf 7 and plant productivity South America, Kay et al. 1997 13024leaching?ay et al . Ec olog y: K P roc. Natl . changesSin 4 (1997) Acad . Sci . U A 9 productivity? Primate species richness and plant productivity Ec olog y: Kay et al . FIG. 2. ( A ) Neotropical primate species richness as a function of rainfall (island dat a removed). (B ) Tree species richness as a function of rainfall (dat a f rom 37 lowland Neotropical localities in ref. 60). ( C ) Number of wet months [as defined by monthly rainfall exceeding 100 mm (61)] as a function of yearly rainfall. Seasonalit y estimates were gathered either f rom reports ac c ompanying the site dat a or f rom climatic maps (10). (D ) Plant productiv it y (indexed by litter fall) as a function of rainfall [dat a f rom 88 lowland tropical localities f rom Asia and the Neotropics (62)]. Using the loess method for local regression (63, 64), lines are fit for each independent variable given rainfall. P roc. Natl . Acad . Sci . U ebruary 25, 2010 o n e c o u l d p r e d i c t t h a t t h e n u m b e r o f p r i m a t e s p e c i es t h a t c a n c oex ist in a forest area is deter mined primarily by seasonalit y. Fig. 2C is a plot of seasonalit y (number of months w ith rainfall exceeding 100 mm) as a function of rainfall. Seasonalit y decreases steadily w ith increaFebruary all u2010 the Thursday, sed rainf 25, p to level of 2500 mm year and then reaches a plateau and does not dimin ish, in c ontrast w ith a decline in primate species richness. Therefore, pronounced seasonalit y may play a role in limiting the max imum number of sy mpatric primates but does not ex plain the decline in primate richness at high levels of rainfall. Histor ical Geog raphy. Historical and geog raphic factors clearly have played an import ant role in shaping plat y rrhine faunal richness (Table 1). Holding rainfall levels and dr y South american primates, Kay et al. 1997 season lengths nearly c onst ant, there are, on average, more primate species per site in larger than in smaller geographically restricted areas. For example, Amazon localities averaged America, South 9 sy mpatric species, Orinoc o and northern c oast al localities have one – half as many species, and the smallest geographic regions (islands and the regions north and west of the A ndes) have the 48 fewest species. I n t h e P l e i s t o c e n e R e f u g i a h y p o t h es i s ( 7 1 ) , P l e i s t o c e n e geog raphic f ragment ation of hitherto more w idely distributed Amazon ian species into smaller forest f ragments promoted genetic divergence and speciation. Then, when the geog raphic isolation was removed, the newly evolved species c ould achieve sy mpatr y thereby increasing species richness. New ev idence calls into question whether such forest blocks Kay et al. 1997 49 r t ion p 2010 Table 1.v iRegua a a o n loc l p im y ec m c n t s Thursday, February 25,lant productivity.alllvyriatilln ipreaserntalte spsyies riphaesric primate species were phy- rainfall exceeding 100 mm) as a function of rainfall. Seasy mpatric species, Orinoc o and northern c oast al localities have Means and SD are given in c olumns 4 – 6. NA, not available. sonalit y decreases steadily w ith increased rainfall up to the FhG. rea.cheLaocatl aregresseison lioinlea– hfaoaradpranryeaponisenpancians wecthefstthsesogntarphechregiohe I 3 s pl a e u and do nes lf s m im s tec ss,orth e d sri s llonege A r des)i ave t ns e e d the ma ,e level of 2500 mm year and t en ( s nds n the gi specia s erilchnn ssr,imate soecalsit y (newmtbser cios. wet months per year), and e d c i n e i e p sea s p n i e u es pe ef not d home messages f Takeimin ish, in c ontrast w ith richness. Therefore, pronolanedpeasdnacitivmt y pls ya folnction of trainleistocTheRefueia areofit sissin1), tPleistocene I n h e P fall. e n e lin g s h y p t h e u ( 7 g h e p u n c t s ro o u l t y i a y a a a r u e in limiting the max imum number of sy mpatric primates but geog raphic f ragment ation of hitherto more w idely distriblneen s rtmvariation 3i,gh theSstructure aandst apeciteiscaltocsmalpextantragments pro- communities is probably o i s p i echniicquess(a6 h 64).els ee Taedle m zon iandiversityooflearisosns. primate e t in lev m r fore t f 1.dBroadx plain the decli oes not e biogeographic ate r hn u t b A 2 for s tis i n FIG. 4. Species richness of Neotropica of rthe ll. ainfa result of a combination of ecological oandenetic divergence and speciation. Then, when the m ted g historical factors. Histor ical Geog raphy. Historical and geog raphic factors geog raphic isolation was removed, the newly evolved species primarily f r uit, leaves, insects, or gum, as a actually ex isted (73). Moreouvear, iine ty mpacrasheroby plcaetayirrhpeces,richness. o he t y te e f in r s ng s inies clearly have played an import ant role in shaping plat y rrhine c ld ch ev s ) c o d n a all l c e an d e erg c n a n ud s i s w including 2.faunal richnesspecies .eHelnit gerviidenevels of dgdrneticaninumberleoftfactors, heghestuch haetarea, slatitude, rainfall, and Primate s (Table 1r richnessnfcorrelates e y with New vv idenee cc ls is to quieetson ug t e r s s t for st block FIG. 2. ( A ) Neotropical primate species richness as a function of rainfall (island dat a removed). (B ) Tree species richness as a function of rainfall (dat a f rom 37 lowland NeotropTablle calitiReinona.l 60).iation iumoealoprwmtamospecieasricefnned by monthly rainfall exceeding 100 mm (61)] as a ical o 1. es gi ref var ( C ) N n lbcr f i e te nths [ s d h i ess function of yearly rainfall. Seasonalit y estimaeesonere gathered eiArer frank reporcs latic o,mpanying ctihe, snte dat a ainffall m clDratimontps ,(10). (D ) th ea rom L o t a i c es n Spe es i im y c ma hs n R t gi w R or ro Plant productiv it y (indexed by litter fall) as a function of rainfall [dat a f rom 88 lowland tropical localities f rom Asia and the Neotropics (62)]. Using Amaz (6 I 9 r 1 (f . l . 2358 (624) 3.22 (2.36) the loess method for local regression on 3, 64), lines are fit for each independent va4i4 ble given .4ain2a9l1) ra Orinoc o and N.E. c oast II 14 4.64 (2.41) 2277 (851) 2.71 (2.20) one c ould predict that the numrterorfwest oftAspes ies that can III season lengths n3.arly1c75nst ant,96here )are, o.33a(3.rage, more e 33 ( . o ) 23 t (978 No b h o p r i m a e ndec 6 2 n ve 20) c oex ist in a forest area is dslter mifnTdinpdimarily by season- I V primate 1pecies per si2e in larger than in smaller Neographically e and o e r i r ad s t gA I 2400 alit y. Fig. 2C is a plot of seaMaraci´ y s(lnnd, ber ap´mBrathls w ith V son al a I a um Am ofa, on zi t restricted areas. For example, Amazon localities6averaged 9 1 2 1600 South american primates, Kay et al. 1997 rainfall, trend lines of local richness of N 50 logegnetically sAreaaarate ocaleifore S3ecm,in lionainfallarsDragon,thsi, n other ep r nk L b it es, n p ies l R ye Re ion y mo n rainfall closely approx imate (and do Amazon o r d s , b e f o r e t h e P l e i s t o c e n e .4( 7 2 )). T358 (624)t h e .22 r2.3a)t c l a d o I 44 9 1 (2.91 2 hus, 3 g(e6 w f rom) those of productiv it y whereas t Orinoc o and N.E. c oast II 14 4.64 (2.41) 2277 (851) 2.71 (2.20) rhine sign ificantly f rom those for tree specie North ogwest i c At i m e d e p t hI o f s y m p a t r i c33 (1.a5)y r2396 (978) s p e.c3 es 0) u g g es t s r e n of ndes II 6 3. p l 7 t 2 3 i (3.2 s Question to Iponderidad leistocene I V efugia1 if they2 ex isted,00playedNlA ttle or no sland ot hrin P f T at 24 R , i alit y. This tight link bet ween product M a r a c ´ I s l a n d , A m a p´ , B r a z i l a a V 1 2 1600 6 i ar g p in n i n s p . A, ot availab . richn to in pri Meanr o l e D n eeivthe ipaucityNt yninsectivorous r i c h n es s . species in Asia relative ess othermates also may ac c ount f s and S thatxen l a c olumng 4 – 6l aof r r h i n eles p e c i es primate Some have suggested Prto uctivit y. A nother hypothesiinsectsain imost sed plant od the scarcity of understory s is th t ncrea Asian forests. in primate species richness w ith altitu continents is due productiv it y leads to increased species richness of an imals part for the decline w ith latitude, both o because at higher pr study it , sp this hypothesis. Your study should bser ved in other t axa. Design an observational, ,comparative oductivtoytestecialized species maint ain are o incorporate ia ilit y (5, 7 within t pr among biogeographic rests i mo t considerationvofbvariation 4). Planandoductiv it y in tropical foareas.sCan syou think of geography has demonstrable inf lu Bio alternative r explain the d by litter fall F primate s litter fall as in Asia? How wouldhyou test a (Table 1) but does no hypotheses to eadily indexerelative lack.ofig. 2D plotinsectivores a function Sout Americ these? of rainfall. A strik ing similarit y is noted bet ween plant proun imodal pattern of primate species Imagine you havedunlimited d primaae speciesofctime,s andmpare Ftosan A and of dedicated undergraduate uctiv it y anfunds, t decade ri hnes (c o access ig . 2 army repeated among biogeog raphic regions research assistantsoth increase w ith aroundl the world. ax imum at 2500 D). B willing to travel rainfal up to a m in primate c ommun ities f rom south Asi mm year and then fall of f at higher rainfall levels. A n ex plapattern is not obser ved in Af rican prim Is this topic amenable to experimental manipulation? Why or why not? nation for this link age may be found in soil nutrient levels and sites have been sampled w ith rainfall available energ y in ec osystems. In areas w ith ver y high rainfall, Preliminar y analyses indicate that, w leaching depletes the level of nutrients and depresses plant in the Neotropics and in tropical As g row th (75). A lso, at ver y high levels of rainfall, cloud c over species numbers and biomass of birds a reduces solar radiation reaching the photosynthetic organs of when c omparing more productive f loo plants, which limits plant production (67, 76, 77). ...
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This note was uploaded on 04/05/2011 for the course ANT 154bn taught by Professor Debello during the Winter '10 term at UC Davis.

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