Exam questions for my section will be based on LECTURE material not text except where I ve used text figures or tables in lecture http ib berkeley edu courses bio1b mcq 20t ips pdf Alfred North Whitehead told us to seek simplicity and A mistrust it B embrace it C further simplify it D use it to forecast ecological change E complicate it More example questions In ecological experiments replicates are NOT A separate independent units of study B treated as identically as possible by ecologists C used to assess variability that arises from factors we didn t manipulate D unmanipulated units used to assess how results are affected by changes over space and time that we did not manipulate E used to assess variability that arises from factors we didn t manipulate 1 2 The earth s major terrestrial biomes as characterized by their dominant vegetation are most clearly separated by In ecological experiments replicates are NOT A separate independent units of study B treated as identically as possible by ecologists C used to assess variability that arises from factors we didn t manipulate D unmanipulated units used to assess how results are affected by changes over space and time that we did not manipulate E used to assess variability that arises from factors we didn t manipulate 3 A B C D E pH and temperature Precipitation and nutrient availability salinity and oxygen concentration Temperature and precipitation Nutrient availability and soil pH 4 Rain shadows and Mediterranean climates e g California if the land is warmer than the ocean moisture in marine air is not dropped until adiabatic cooling over mountains summer drought If land cooler than ocean moisture is dropped winter rains Habitats resources conditions and niches Rain shadow Eastern Sierra 5 6 Water ends up in lakes rivers or ground water Lake temperature and mixing regimes water is densest at 4oC winter and summer stratification spring and fall overturn Thermocline stratum of rapid temperature change Can separate oxygenated from hypoxic habitat Eutrophic river lake estuary nutrient rich likely to produce noxious or harmful algal blooms cyanobacteria toxic dinoflagellates Mesotrophic intermediate nutrient concentrations Oligotrophic low nutrient concentrations very clear water good water quality for humans and fish Mixing replenishes nutrients for algae in photic zone 7 River networks Easier for wind to stir nutrients in shallow basin making such lakes vulnerable to eutrophication 8 Rivers in drainage networks Downstream concentrative fluxes of water sediment solutes detritus and passive organisms Headwaters woody debris forest cover Meandering middle reaches clean gravel beds hyporheic under the stream bed habitat undercut rooted bank vegetation off river habitat Upstream and upslope dispersive backflows of mobile organisms Systematic downstream increases in discharge solar radiation and changes in sediment size habitat structure and disturbance regimes Confluence nodes pulses of enrichment adjacency of contrasting habitats refuges David Schindler s experimental lakes A 5 km2 Lowland floodplain rivers floodplain marshes or forests off channel water bodies 9 10 Camille McNeely downstream changes in energy sources to grazers 11 12 Energy carbon sources change downstream River Continuum Concept Vannote et al 1980 Estuary where rivers empty into oceans fresh water 0 salt meets salt water 3 salt tidal prisms with heavier salty water underneath Terrestrial detrital carbon e g dead leaves that fall into streams Attached algae Fine particulate detritus and phytoplankton 13 Important nurseries for offshore fisheries Tidal prism wedge of fresh water overlies denser salt water 14 Detritus dead organic matter Neritic nearshore subtidal Benthos life on substrate or bed of sea lake spring or rivers and streams 15 Pelagic Offshore beyond Continental Shelf 17 Structure Cover Food Plankton passive drifters Nekton active swimmers zooplankton phytoplankton 16
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