ECOSYSTEMS & BIOMES ECOSYSTEMS SUPPORT LIFE MATTER CYCLES THROUGH ECOSYSTEMS ENERGY FLOWS THROUGH ECOSYSTEMS BIOMES CONTAIN MANY ECOSYSTEMS

ECOSYSTEMS SUPPORT LIFE Living things depend on the environment Biotic factors interact with an ecosystem Many abiotic factors affect ecosystems

Living things Depend on the Environment Ecology: scientific study of how organisms interact with their environment & all other organisms in that environment. Ecosystem: particular environment & all the living things that are supported by that environment. (pond or desert) Biotic factor = living part of ecosystem. Living things depend on ecosystem for food, air, water & other survival needs. Plants are important biotic factor (important food source, can block sunlight & affect temp., roots hold soil in place, clean air, etc.) Animals are also imp. Biotic factor (beaver builds dams, large herds may eat grassland & cause erosion; coral gives food & cover in oceans.

Many Abiotic Factors affect Ecosystems Abiotic factors are the physical & chemical parts of an ecosystem. Physical (temp., water, sunlight) & chemical (minerals, compounds in soil/water) factors determine the types of organisms that an ecosystem can support. Some abiotic factors are: temperature, light, soil, and water.

Abiotic Factor: Temperature TEMPERATURE: Affects types of plants that will do well (thereby determining what animals). Tropics support lush plants supporting many types of organisms (monkey, birds, reptiles, etc.) Animals are sensitive to temperatures too. Musk oxen have thick fur & can survive in very cold temp. (-40 o F), but water buffalo with light coat lives where it only gets about 48 o F.

Abiotic Factor: Light The strength of sunlight in an area determines the types of plants found there (cacti in strong light, moss & ferns in weaker light/blocked light) Light is factor in ocean too: deep ocean with little light has very different organisms, compared to shallow water organisms. Light can be captured through photosynthesis in the first hundred meters below the ocean’s surface. Sunlight warms the Earth’s surface & atmosphere. Energy from the sun supports most life on Earth. Plants capture sun’s energy to make food via photosynthesis. This gives food for other organisms.

Abiotic Factor: Soil Soil: mixture of small rock and mineral particles. Organisms within soil break down remains of dead plants & animals. This decay is important in giving raw materials to living parts of ecosystem. Characteristics of soil affect plant growth. If a lot of decaying, organic matter, can hold water well (unlike sandy soil or clay soil). Minerals in soil also affect plant growth.

Abiotic Factor: Water All living things need water to carry out life processes. Plants need it for photosynthesis, animals need it to digest food & release energy stored in food. If Ecosystem has lots of water, can support many different types of plants & thereby animals. Tropical rain forest is the wettest ecosystem & holds the most diverse organisms. Deserts have very limited plants & animals.