The study of organisms and their environment Ecology The study of organisms and their environment

ECOSYSTEMS All of the biotic parts (living, such as bacteria, fungi, animals, etc.) and the abiotic parts (nonliving, such astemperature, wind, water, etc.) together make up an ecosystem

A Stable Ecosystem: Population numbers fluctuate at a predictable rate Supply of resources fluctuate at a predictable rate Energy flows through the ecosystem at a fairly constant rate over time

There are limiting factors in an ecosystem that control the number of individuals that can live there Limiting factors are space, food, water, mates, oxygen, nitrogen in soil, etc. Limiting factors limit the number of individuals that can inhabit an ecosystem Limiting factors cause competition among organisms

Limiting factors determine the carrying capacity – maximum number of individuals that can live in an ecosystem

Niche The combination of where an organism fits into the food web, the specific habitat in which it lives, how it obtains food, their behavior, etc.

Exponential Human Population Growth Has Placed Tremendous Strains on the Environment for Resources

HUMAN POPULATION GROWTH HAS AN EFFECT ON: Food shortages Large amounts of waste produced Lowers the amount of available fertile soil Demand for land has led to deforestation which can increase erosion rates

Increases acids produced in the atmosphere due to burning of fuels from cars, factories, etc. Higher production of chemicals that can damage the environment (CFCs for example) Decreases the availability of renewable and nonrenewable resources

Contribute to poorer air quality Decreases the amount of clean water Larger amounts of waste products Some waste products are not biodegradable or are toxic to the environment (Freon for example) Use of chlorofluorohydrocarbons (CFCs) contributes to the depletion of the ozone layer that protects the earth from UV rays from the sun

Burning of fossil fuels for energy and transportation increases greenhouse gases released into the atmosphere (mostly CO2), which increases global temperatures that affect sea levels, climate and atmospheric composition

GEOCHEMICAL CYCLES Movement of a particular form of matter through the living and nonliving parts of an ecosystem Earth is a closed system, because matter changes form but is neither created nor destroyed; it is used over and over again

CARBON CYCLE Carbon is recycled as CO2 is used in photosynthesis to make sugars, then given as during cellular respiration as sugars are broken down for energy

NITROGEN CYCLE Nitrogen is fixed by bacteria in the soil; they take atmospheric nitrogen and convert it in nitrates that plants can use

WATER CYCLE

BIOTIC AND ABIOTIC FACTORS Biotic factors are the living parts of an ecosystem (plants, animals, fungi, bacteria, etc.) Abiotic factors are the nonliving parts of an ecosystem (temperature, pH, light, oxygen, nitrogen, soil, etc.)