4-2 What Shapes an Ecosystem?

5. 4-2 What Shapes an Ecosystem? • Habitat is shaped by: (like an address) • Biotic factors – the ecological community. Ex. birds, trees, mushrooms, and bacteria. • Abiotic factors- the climate of an area. Ex. temperature, precipitation, and humidity.

6. Niche • The physical and biological conditions in which an organism lives and the way in which an organism uses those conditions. • Temperature it survives in • Type of food it eats • What eats it • How it obtains food • How it reproduces

7. Ex. of Niche Bull Frog(amphibians) • In or near ponds, lakes, or slow moving stream • Eats; insects, spiders, worms, small fish, and mice. • In winter, they burrow in the mud and hibernate. • Reproduction- Female bullfrogs lay eggs in water during warmer months.

8. The Niche Competitive Exclusion Principle- No two species can occupy the same niche in the same habitat. They can occupy niches that are similar. Ex. Bay Breasted Warbler Cape May Warbler Yellow-Rumped Warbler They avoid direct competition

9. Community Interactions • 1. Competition – Will result when two of the same species or different species attempt to use the same resources (food,water, light, nutrients, or space) in the same place at the same time. • Ex. Oak and Hickory trees grow tall and leaves are broad. They block out the sunlight for shorter trees.

10. Competition • Competitive Exclusion Principle- Competitions results in a winner and a loser- with the loser failing to survive.

11. Predation One organism captures and feeds on another organism. The organism that does the killing is the predator. The food organism is the prey

12. 2. Symbiosis- Any relationship where two organisms live closely together. • Mutualism – Both benefit. Ex. flowers and insects • Commensalism- One benefit and the other is not helped or harmed. ex. barnacles attach to whale skin. • Parasitism- One organism lives in or on another and harms it. The one being harmed is called the host. Ex. fleas, ticks, lice, tapeworms.

13. Ecological Succession • Series of predictable change that occur in a community over time. • Primary succession- Occurs where no soil exists. Ex. As volcanic islands form. Ex. When glaciers melt exposing bare rock.

14. Pioneer Species • Stage one primary succession. • Ex. Lichen (fungus and alga) they break down rock. When they die the material become soil. Now other plant and organisms begin to arrive. • Ex. Mosses.

15. Stage 2 accumulation stage Annuals dominate soil. Nutrient pore soil. Ex. Plants like legumes have relationship with rhizobiabacteria(nitrogen fixing) Decomposition of bacteria and fungi and waste of small animals all add to soil.

16. Soil vs. dirt • Soil is alive • Dirt is minerals

17. Stage 3 perennial herb stage • Soft tissue perennials dominate. They may take several years to reproduce. • They will out compete annuals b/c they can reproduce sexually. Annual will be present but perennials dominate. • They modify the soil for the next stage.

18. 4. shrub stage – Woody multi stemmed plants less than 10 feet. • Modify soil for the next stage…. 5. Shade intolerant trees- Require and or tolerate high sunlight. Pine tree. Fire adapted may never reach stage 6. 6. Shade tolerate- Trees can grow and thrive in shade. Ex. Oak and hickory.

19. Stage 6. Canopy forest- see picture on board. • Shade tolerate out compete shade intolerant. • If you make it to stage 6 you don’t always stay there. Ex. Tree falls from wind. Insect damage. Fire comes in. • When there is a disturbance you will see a mix of stages.

20. Stage 6 used to be called climax forest. • Ecologist are getting away from that term. Why do you think? Once you reach stage 6 you may call it Oak & Hickory forest b/c they dominate. But there is always patches of disturbance.

21. Secondary seccesion • Same as primary except no stage 1 or 2.. Ex. An old abandoned farm.

22. Old Growth vs. Immature Community 1. OG reaches stage 6. 2. OG is moist compared to IC. 3. OG highly organized many layers. Canopy, sub canopy, shrub layer. 4. OG differs in species diversity may have high or low.

23. Succession of Marine Environment • Dark ocean floor, a whale falls to the bottom and dies. Scavengers and decomposers come to the scene to feed on the whale. Ex. Sharks,, hag fish, bacteria, and amphipods. • Within a year most whale tissue is gone; crabs, snails, small fish, use site for shelter. Bottom of ocean is enriched, many worm species.

24. 3. Heterotrophic bacteria move in, feed off of oils inside decomposing bone. • As they feed they release chemicals that attract chemosynthetic bacteria. • Chemosynthetic bacteria are a food source for mussels, limpets, snails, worms, crabs, clams, etc….

25. Biomes Tropical Rain Forest Tropical Dry Forest Warm Wet & dry seasons Deciduous Hot and wet all year Broad leaf evergreen Climbing plants Nutrient poor soil

26. Biomes Tropical Savanna Desert Less than 25 cm a year. Extreme temp. changes Rich in minerals poor organic Extensive root system Warm Seasonal rainfall Frequent fires

27. Temperate Grasslands Temperate woodland and shrubland AKA chaparral Hot & dry summers Cool & moist winters Freq. fires • Mix of grasses • Fertile soil • Moderate temp. • Seasonal rain

28. Boreal Forest aka. Taiga • Long cold winter • Short warm summer • Moderate rain • Needle leaf conifers • Nutrient poor soils • Wolves, moose, spruce

29. Tundra • Permafrost • Short cool summer • Low rain • Mosses, lichen, short grasses

30. Mountain Ranges Polar Mosses, lichen, mites, polar bears, penguin, rates • As you go up it gets colder • More rainfall on one side of the mountain

34. Sec. 5-1 • Population density-Number of individuals per unit area. • Population growth- Births, deaths, immigration, and emigration.

35. Exponential growth- When individuals grow at a constant rate. see fig.5-3 • Logistic growth-when population growth slows or stops following a period of exponential growth.

36. Carrying capacity is the largest number of individuals an environment can support.

37. Do Now: If an entire lynx population disappears, What is likely to happen to the hare population on which it preys? • Objective :Explain why population rates differ from country to country.

38. Sec 5-3 • Demography- Study of human population • Demographic transitions- a dramatic change in birth and death rates.see fig.5-12 • Age structure diagrams- population profile by age. See figure 5-13

39. Future population growth • Some scientists believe that if the population growth rate does not slow down, humans will outgrow our food and other supplies. And bust will occur. • Other scientist think that technology will handle any problems with supplies and ecosystem recovery and the human population will remain stable. • What’s you opinion?