RNR test 2 notes - RNR Study Guide Exam 2 Forests Forest...

RNR test 2 notes
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RNR Study Guide Exam 2 Forests Forest Controversies Forest Values Open and Closed forests Hardwoods and Softwoods Hardwood: a species of tree, such as oak, hickory, and maple that has relatively hard wood, in contrast to the soft woods of the conifers such as spruce and pine. DECIDUOUS Softwood: a species of tree such as spruce, pine, and fir that has softer wood than hardwood trees such as oak and hickory. CONIFERS Stand Forest Succession Climax Community The stable terminal stage of an ecological succession. Secondary Forests Old-Growth Forests Snags Factors that determine tree survival and distribution Shade-tolerant and shade-intolerant species Seed dispersal and germination
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Pattern and rate of growth Tolerance of soil type Size/age at maturity Resistance to fire—surface fires and crown fires Surface Fires: “cool”, low level fire Burns undergrowth and litter Removes competing plants which is positive for the tree Releases nutrients into the soil Kill Fungi, which are bad for the tree Improves wildlife forage Prescribed burning is an important forest management too—makes forest much more healthy Crown Fires: extremely destructive Burn entire forests More common in fire—suppressed areas Litter accumulation Forest, wildlife, erosion impacts Fire = Negative Impact? Used to be considered negative. After research fire is considered to be a key role in forest ecology. -Thick, Fire-resistant bark -Rapid regeneration after fire -Some trees include fire in their life history—need fire to reproduce -Fire climax trees: Giant sequoia, Longleaf pine—need fire to reproduce Diseases and parasites Parasite fungi = most destructive Viruses, Bacteria, Nematodes, Mistletoe Most destructive on tree farms
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Exotics problematic (chestnut blight, Dutch Elm) Insects Bark Beetles of pine and fir trees Wood borers Larval insects: defoliators—eating the leaves Sucking insects, like aphids Pollution, SPMS, Ozone Industrial urban areas in MDCs Acid rain, ozone, and SPM: dust, soot, asbestos, heavy metals Leaf and bark damage, increased susceptibility to pathogens World Forest Forest cover 34% of world’s terrestrial biomes Forestland decreasing in approx. 55% of countries, increasing about 32% 0.22% loss of forest area/year during 1990’s Deciduous needleleaf- baldcypress= lowest Deciduous broadleaf= 2 nd lowest Evergreen needleleaf= 3 rd lowest Evergreen broadleaf= highest Firewood shortages 50% of annual harvest is used for heating and cooking By 2000, 3 billion people in 77 LDCs with firewood shortages Burden on poor and women(bc women go out and get wood) Burn manure and crop waste Economic impacts of fuel changes—wood burning stoves =economic loss Fuel wood consumption: South America and North Africa increase- they could switch to charcoal Increasing World Forest Yields LDCs must plant more trees Increase efficiency, switch to other fuels
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