NRC 261 1st Edition Lecture 4Outline of Last LectureI. Medieval EuropeII. Era of AbundanceIII. Era of Exploitation a. Yellowstone Protection Act (1894) IV. Era ofProtection a. Lacey Game & Wild Bird Preservation Act b. Migratory Bird Act (1918) c. Refuges V. Era of Game Management a. Aldo Leoplod b. Federal Duck Stamp c. Pittman Robertson Act (1937) VI.Environmental Management Era a. National Environmental Policy Act (1969) b. Endangered Species Act (1973) c. CITES (1975) d. Section 404 of Clean Water Act (1978) e. Food Security Act “Farm Bill” (1985) VII. Current Protection Measuresf. Jurisdiction g. Legal Status VIII. How does history of legislation reflect changes in attitudes & values?Outline of Current LectureII. Wildlife Diversity a. Parts of Ecosystems b. Scale of Ecosystems III. Interactions a. Trophic Levels b. Energy Loss c. Niche IV. Habitata. Food b. Water c. over-Thermald. Cover-Behavioral e. Space Current LectureEcosystems & HabitatsWhat kind of “habitat” is best for wolves?Wildlife Diversity= the richness, abundance & variability of wildlife species and communities, the ecological processes that link species to one another and the environment• diversity is the interaction of organisms with each other and their environment • John Muir — founder of the Sierra Club • everything is interconnected • the first rule is to save all the pieces—important because you don’t yet knowwhat is essential • consequences to losing species or changing environments • example: wolves being reintroduced to Yellowstone —> less elk, but also — >lesscoyotes —> more foxes —> fewer mice• CASCADES • some animals are specialized to areas and some aren’t • diagram shows the span of environments that a certain species can live in ex: short tailed shrew can live anywhere • So how does it all fit together? • depending on where species live — different food, predators etc. Parts of Ecosystems• Abiotic = non-living • elements/minerals • soil • water • air—lots of moisture, density at different altitudes etc. • Biotic = living • plants • animals • fungi Scale of Ecosystems• Spacial/geographical — some places that are contained ecosystems • island — interacts with itself only • planet = 1 giant ecosystem—no place on earth is unaffected by the by-products of humans • ex: polar bears in isolation (area far from humans) were found withpollution in their livers • time — sometimes just a 24 hour span (solar radiation, light, temp.)• some shorter = tides (12 hour period) • major processes in ecosystem can change over short or long periods of time • some longer = thousands, millions of years (global warming/climate change)• 10,000 years ago Massachusetts was under 1 mile of ice • the oldest animals have around 150 year life span — much shorter than many trees(such as sequoias that live for thousands of years) Interactions• cycling of nutrients —plant growth, the water cycle • animals die —> remains go into soil —>plants —> animals • some places lack nutrients, other places have too many (both can be bad) • Energy Flow: Food Webs • things eat other things • ex: arctic ecosystem • phytoplankton —> zooplankton —>fox —>puffin BUT the fox also eatsthe rat which also eats the puffin • not just a chain, but all interconnected • producers = plants (utilized for growth) • consumers = usually animals • herbivores : plant eaters • carnivores : meat eaters • omnivores : eat both plants and meat • Detritivores : eat dead things (decomposers) Trophic Levels• primary consumers eat primary producers• secondary and tertiary consumers eat primary consumers (they’re the predators) • loss of total energy happens as you move up the trophic chain (primary —>quaternary) • why big, fierce predators are more rare — less of them in terms of bio-mass • as position up the chain increases, so does the number of energy transfer steps Energy Loss• takes energy to stay alive (respiration) • energy from the sun —> plants — lots of that energy that isn’t availablefor herbivores to consume • not able to be passed onto the next trophic level—plants need to usethat E to live • even less energy available for carnivores than herbivores • in a given system, there’s not enough energy to sustain all that many ofthem — another reason why there are less of them than prey animals & plants • ex: Isle Royale • simple northern forest system with 3 trophic levels • major herbivore = moose (some hares) • major carnivore = gray wolf (some red foxes) • less biodiversity • scales of change in moose population & wolf population — averagepopulation of moose is 1000, average population of wolves is 20 • fewer predators — less efficient at energy conversion • vegitation can support about 1000 moose and about 20 wolves — becausesome moose energy lost in transition between steps **all systems are set up in a similar way!*Niche= ecological role of a species—how it fits into the rest of the ecosystem• niche breadth — how wide is the niche? • what is the variety of resources used? • what is the range of conditions used? • generalist = wide • ex: red fox eats a wide variety of food & lives in a wide variety of places—one of the worlds widest range carnivores • specialist = narrow • ex: black-footed ferret in U.S is endangered, they only prey on prairiedogs & only live where there are prairie dogs • Niche overlap • every species has a unique niche — individual organisms can live outside oftheir niche but populations can’t • reproduction and/or survival are compromised outside their niche (habitat) • limit — outside those limits unable to survive as a species • can share resources in space or time • ex: Warblers • canadian warblers nest all over northern U.S & canada • Kirthland warblers only nest in a certain tree that grows in thenorthern peninsula of Michigan • broad vs. narrow habitat requirements = habitat generalists vs. specialists Habitat= resources necessary to support a population over space & through time• food• water — kind, distribution, abundance • cover • space • Context • habitat “types” = generalized classifications of species associations (grassland, forest,desert, etc.) • niche • habitat is species specific • may be 1-2