Ecosystem Ecology

Ecology “study of the interactions between the organisms and their environment”

BioticAbiotic Living organisms Nonliving organisms Wildflower, animals, bacteria Sunlight, precipitation, temperature, soil, rock

Flow of Energy Photosynthesis a. Sun + 6 H 2 O + 6 CO 2  C 6 H 12 O O 2 b. performed by plants, algae, and some bacteria

Cellular Respiration a. C 6 H 12 O O 2  Energy + 6 H CO 2 b. fuels own metabolism and growth c. aerobic v. anaerobic

Trophic Levels/Feeding Levels

Food Chain v. Food Web ____ (modified (modified)

Scavengers a. consume dead animals (vulture) Detritivores a. break down dead tissues and waste products into smaller particles (dung beetles) Decomposers a. complete the breakdown process by recycling the nutrients from dead tissues back into the ecosystem (fungi, bacteria)

Gross Primary Productivity ex) total paycheck Net Primary Productivity ex) paycheck after taxes

Energy Flow Biomass: total mass of all living matter in an ecosystem Energy is lost at each level (heat) a. 10% gained; 90% lost b. ecological efficiency

Matter Cycles Through the Biosphere Biosphere: combination of all ecosystems on Earth Biogeochemical Cycles: movements of matter within and between ecosystems that involved biological, geological, and chemical processes

The Hydrologic Cycle 1.Evaporation 2.Transpiration 3.Infiltration 4.Precipitation 5.Condensation 6.evapotranspiration 7.Runoff

Human Activities a. harvesting trees - decreased evapotranspiration, increased runoff b. construction

The Carbon Cycle 1.Photosynthesis 2.Respiration 3.Exchange 4.Sedimentation and burial 5.Extraction 6.Combustion

Humans and the carbon cycle a. combustion of fossil fuels b. deforestation

The Nitrogen Cycle Nitrogen a. proteins and nucleic acids b. useable form  nitrates and nitrites c. earth’s atmosphere  78% nitrogen gas d. most abundant element in the atmosphere

Steps a. nitrogen fixation (nitrogen gas-N2) into ammonia-NH3) b. nitrification (ammonia to nitrites and nitrates) c. ammonification (decomposers) d. denitrification e. leaching

Human affect Deforestation Fertilizers runoff

Phosphorous Cycle Major component of DNA, RNA and ATP Doesn’t exist in atmosphere a. limited to soil and H 2 O

Steps a. weathering of phosphate rocks b. plants take up phosphate from soil and animals eat the plants c. decomposers release phosphate back in to soil d. animal excretion

Human Influence Fertilizers Runoff into aquatic ecosystem a. excess growth of algae (algal bloom) resulting in hypoxia Found in detergents

Calcium, Magnesium, Potassium and Sulfur Important in transmitting signal between cells Derived mostly from rocks and decomposed vegetation Calcium and Magnesium – limestone and marble

The Sulfur Cycle Similar to phosphorous cycle Important for proteins Found mainly in rocks and soil (coal, oil) as minerals

Steps a. Weathering b. plants and animals relationship c. decomposers - sulfates convert to hydrogen sulfide gas which escapes into atmosphere, water, soil, marine sediments * result in acid rain

Human Influence Emissions from coal-burning power plants

Ecosystem Disturbances Disturbance: event caused by physical, chemical, or biological agents that results in changes in population size a. natural and anthropogenic

Understanding Biogeochemical Cycles a. helps in determining change by disturbance b. watershed studies - watershed: all of the land in a given landscape that drains into a stream, river, lake, or wetland

Resistance v. Resilience a. resistance: measure of how much a disturbance can affect the flows of energy and matter b. resilience: rate at which an ecosystem can bounce back

Intermediate Disturbance Hypothesis a. rare disturbances  low diversity b. frequent disturbances  low diversity c. intermediate disturbances  highest diversity

Ecosystem Services Instrumental Value a. value in terms of how much economic benefit b. ecosystem services c. provisions Intrinsic Value a. moral value of an animal’s life