Unit Five Ecology and Conservation Biology

1. Unit FiveEcology and Conservation Biology Biogeochemical Cycles, Energy, and Ecosystems

2. Earth’s Environmental System Ecologists study the interaction between abiotic and biotic factors in an ecosystem Ecosystems, if healthy, are in a state of dynamic equilibrium i.e. they are always undergoing some type of fluctuation in number of individuals of a species or nutrient content Dynamic equilibrium relates directly to the concept of a feedback loop

3. Earth’s Environmental System cont’d All ecosystems are open systems in that energy and matter are exchanged between them The Earth can be divided into parts: Lithosphere – rock and sediment on the various land masses Atmosphere – gases surrounding the planet Hydrosphere – the water on the Earth Biosphere – all parts of the Earth that support life

4. Earth’s Environmental System cont’d Landscape Ecologists study broad areas and attempt to learn more about the gradual changes in vegetative associations that occur over hundreds of kilometers While traditional ecologists focus their attention on ecosystems, landscape ecologists study many ecosystems at once While conducting research, both ecologists and landscape ecologists study ecotones, transition areas between two ecosystems/biomes where plants from both ecosystems/biomes are found

5. Ecotone

6. Earth’s Environmental System cont’d Producers a.k.a. flora, plants, and autotrophs, are always at the bottom of the food chain because all other living organisms depend directly or indirectly on them Producers carry out photosynthesis which supplies their cells with energy to maintain themselves and extra energy to grow

7. Earth’s Environmental System cont’d The overall production of energy by producers is called gross primary production The extra energy that producers use to grow that is in addition to the energy needed to maintain cells is called gross primary production Biomes such as desert, tundra, and open ocean have low net primary productivity

8. Biogeochemical Cycles The availability of nutrients in addition to ample amounts of sunlight and water determine what areas of the Earth have high net primary productivity In other words, it is not just water and sunlight that are important for plant growth Nutrients such as carbon , nitrogen, and phosphorus are needed for substantial plant growth

9. Carbon Cycle

10. Nitrogen Cycle

11. Phosphorus Cycle

12. Hydrologic Cycle

13. Geological Systems: How Earth Works The rock cycle is also very important to the existence of life The rock cycle is directly involved in the recycling of phosphorus Plants have to attach themselves to some type of substrate in order to survive; they cannot live freely in the air Most plants grow out of soil A few plants can live directly on top of rock - pioneer species Additionally, a few plants called epiphytes live off the ground attached to the bark of trees

14. Geological Systems: How Earth Works cont’d The rock cycle is defined as the means by which rock is formed, changed, and reformed by heat, pressure, and time Rock is divided into three categories based on how it is formed and its chemical composition Igneous – heat is required Metamorphic - heat and pressure are required Sedimentary - pressure is required

15. Geological Systems: How Earth Works cont’d The majority of the fossil record used to construct the Geologic Time Scale and additionally support the theory of evolution is found in sedimentary rock.....why?