ENVIRONMENTAL SCIENCE

1. ENVIRONMENTAL SCIENCE EXAM II POWER POINT

2. ECOLOGY Can be studied at various levels (e.g., population, community, ecosystem)

3. Population Ecology Population – a group of individuals of the same species living in a given area Limiting factors are essential resources that are in short supply. They influence the size (N) of a population

4. Population is increased by Births Immigration Indirectly by technology, medicine, green revolution et.

5. Population is decreased by Deaths Emigration Indirectly by diseases, catastrophes etc.

6. Exponential population growth N doubles each generation Produces a J shaped curve IS NOT REALISTIC over the long term

7. Logistic growth N increases exponentially until the carrying capacity (K) is reached Produces an S shaped curve (theoretical) with oscillations around K (realistic) With oscillations around K, realistic for many species

8. K selected species Produce few, relatively large offspring Lots of parental care Reproduce at relatively later ages

9. r selected species Produce many, relatively small offspring Little to no parental care Reproduce at relatively young age

11. Community Ecology Community – a group of individuals of different species living in a given area Limiting factors are essential resources that are in short supply. They also influence communities.

12. Community Ecology Structure influenced by • Abiotic factors • History of the area • Random events • Predator-prey interactions • Interspecific interactions

13. Abiotic factors

14. History of area

15. Random occurrences

16. Predator-prey interactions predation, parasitism, herbivory where one species feeds on members from other species. Predators do the eating and are almost always animals, but prey may be animals, plants, fungi, protists, or bacteria.

17. Robert Payne’s Keystone predator experiment The experiment had two treatments, enclosures with Pisaster and enclosures without Pisaster. The findings were that species diversity went down without Pisaster and was high with Pisaster. This is mostly because mussels become the dominant species and out compete other organisms.

18. Interspecific Competition Interspecific competition is competition for limiting resources between individuals of different species (on the contrary intraspecific competition is competition for limiting resources between individuals of the same species).

19. Interspecific Competition II Each species that is present in the community has a niche that is the role that that species plays in the community. The niche of each species is multidimensional and three of these dimensions are most commonly studied: place, time and resource.

20. Interspecific Competition III Two species cannot occupy the same niche in a given area without one of the species going extinct (which is what happens when humans and the species that are associated with us occupy new areas- we drive the other species that need the same resources to extinction

21. Interspecific Competition IV Robert MacArthur’s warblers

22. Other Interspecific Interactions

23. Commensalism is a type of symbiosis where the members of one species benefit from the association while the members of the other species are neither benefited nor harmed. Cattle Egret eating insects disturbed by the buffalo

24. Mutualism is a type of symbiosis where the members of both of the species benefit from the interaction.

25. Predation or Parasitism is also a type of symbiosis where members of one of the species benefits while the other is harmed

26. Biomes Terrestrial biomes are classified according to the predominant vegetation and are characterized by adaptations of organisms to that particular environment

27. Tundra The northernmost tundra is characterized by the presence of grasses, shrubs, and lichens (no trees), permafrost, cold temperatures, and little precipitation. Animals found there include musk oxen, lots of mosquitoes and other biting insects, ptarmigan, and arctic hares. Major environmental concerns are drilling and transporting oil.

28. Tiaga or Coniferous forest biome South of the tundra is the Tiaga (AKA Northern Coniferous Forest Biome or Boreal Forest) which has a short summer season (expect for coastal areas) and is characterized by the presence of conifers, bears, moose, deer, foxes, snowshoe hares etc. The winters are cold and there is a moderate to high amount of precipitation depending on the geographic location. Soils are usually nutrient-poor and acidic. Environmental concerns include overharvesting of timber.

29. Temperate deciduous forest The temperate deciduous forest biome is characterized by abundant precipitation, deep rich soil, broad-leafed deciduous trees, a long growing season, maple, oaks, deer, raccoons etc. Much of these forests are already gone

30. Tropical Dry forest Inthe tropics, the tropical dry forest (AKA Tropical deciduous forest) occurs in relatively dry areas (at least for part of the year), rains can be heavy during the rainy season, but the dry season lasts about half of the year. Consequently, the species found there are adapted to these wide variations in water availability or they may migrate when necessary. Deforestation and wide spread grazing have caused environmental problems.

31. Temperate Grassland The temperate grassland biome is characterized by an intermediate amount of precipitation, relatively flat terrain, grasses (short-grass prairie or tall grass prairie), lack of trees, periodic fires, rich soils, pronghorn, prairie dogs, coyotes, etc. Much of this biome has been taken over for grazing land and agriculture.

32. Savanna Tropical grasslands are referred to as savannas. They have some trees and rainy seasons. Lots of grazers and their predators occur there and some of them migrate seasonally.

33. Chaparral The chaparral biome is a grassland/shrub/small tree biome. There is insufficient precipitation to support trees. It is a warm biome and most importantly is it is fire-prone and fire-dependent.

34. Desert The desert biome is characterized by a lack of precipitation (except rare to occasional downpours, lots of sand, mesquite trees, cacti, lizards, rodents etc). Environmental concerns include increasingly large cities (dependent on irrigation), expanding deserts from semi-arid regions, and the fragile nature of this biome. Many deserts are hot (at least during the day), but there are cold deserts

35. Tropical Rain Forest The tropical rainforest biome is characterized by a great deal of precipitation, relatively constant warm temperatures, the highest biodiversity, nutrient-poor soil, monkeys, jaguars, lots of amphibians, etc. Environmental concerns include deforestation (at a rate of an area the size of Washington each year). If this continues these forests will be gone in 100 years or less.

36. Temperate rainforest There are also temperate rainforests where the temperature does not remain constant but rainfall is heavy (e.g., of the Pacific Northwest with lots of slugs and the spotted owl. Timber harvest is one of the biggest concerns in this biome.