NRC 261 1st Edition Lecture 4 Outline of Last Lecture I Medieval Europe II Era of Abundance III Era of Exploitation a Yellowstone Protection Act 1894 IV Era of Protection 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 Measures f Jurisdiction g Legal Status VIII How does history of legislation reflect changes in attitudes values Outline of Current Lecture II Wildlife Diversity a Parts of Ecosystems b Scale of Ecosystems III Interactions a Trophic Levels b Energy Loss c Niche IV Habitat a Food b Water c over Thermal d Cover Behavioral e Space Current Lecture Ecosystems Habitats What 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 know what is essential consequences to losing species or changing environments example wolves being reintroduced to Yellowstone less elk but also less coyotes 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 byproducts of humans ex polar bears in isolation area far from humans were found with pollution 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 eats the 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 available for herbivores to consume not able to be passed onto the next trophic level plants need to use that 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 of them 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 average population 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 because some 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 prairie dogs only live where there are prairie dogs Niche overlap every species has a unique niche individual organisms can live outside of their 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 the northern 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 things that are really important and others that are less so habitat is NOT just vegetation good habitat for wolves lots of prey vegetation they can live in the arctic the desert lush temperate forests couldn t be described in terms of vegetation few people who want to kill them in general a good habitat is a place where a species is relatively safe from threats Food Abundance distribution more is better food is easier to get digest costs less energy wise ex leopard graph show good correlation between amount of food and of leopards 600 kg of prey is required to support 3 kg of leopard more food makes reproduction easier ex lion compares biomass prey and cub survival more food females in better condition and better