Interactions of Living Things

Ecology Ecology is the study of interactions that occur among organisms and their environment.

Ecosystem An ecosystem is all the organisms living in an area and the nonliving parts of their environment.

Abiotic Factors Living or once-living environmental features are called biotic factors. Animals Plants Abiotic factors are nonliving physical features.

Abiotic Factors Atmosphere-the air that surrounds Earth Water-the major ingredient of the fluid inside the cells of all organisms.

Abiotic Factors Soil-a mixture of mineral and rock particles, the remains of dead organisms, water, and air. Sunlight-the source of energy for most life on Earth.

Abiotic Factors Temperature Most organisms’ body temperatures should stay within the range of 0 ̊C to 50 ̊C for survival. Temperature is affected by latitude; areas closer to the equator are warmer than areas farther from the equator. Elevation-distance above sea level that affects temperature, wind and soil.

Abiotic Factors Climate-an area’s average weather conditions over time, including temperature, precipitation, and wind. For most living things, temperature and precipitation are the two most important components of climate. Heat energy from the Sun creates air currents called wind.

Discussion Question What abiotic factor supplies energy for most life?

Biotic Factors A population is made up of all the organisms in an ecosystem that belong to the same species. A community is all the populations in an ecosystem.

Biomes Factors that affect biomes climate: Temperature Precipitation Major biomes-large areas with similar climates and ecosystems.

Tundra Cold, dry, treeless region Permanently frozen soil called permafrost Average winter temperature: -12 °C Average precipitation is less than 25 cm per year. Plants: mosses, grasses, small shrubs, lichens Animals: insects, ducks, geese, other birds, mice, arctic hares, reindeer

Taiga Cold forest of mostly evergreen trees. Soil thaws in the short summer Precipitation: mostly snow, 35 cm-100 cm per year.

Temperate Deciduous Forest Region with four seasons, mostly trees that lose their leaves in autumn. Temperature range from below freezing in winter to 30°C or more in summer. Precipitation: throughout the year, 75 cm -150 cm per year.

Tropical rain forests The most biologically diverse of all biomes Average temperature: 25°C Precipitation: 200 cm – 600 cm per year. Four zones: forest floor, understory, canopy, emergents Human impact: Habitats being destroyed by farmers and loggers.

Desert Driest biome, supports little plant life. Temperatures: vary from hot to cold. Precipitation: less than 25 cm per year. Soil: thin, sandy, or gravelly Plant: cactus Animal: kangaroo rat

Grasslands Prairies or plains, dominated by grasses Temperatures: temperate or tropical Precipitation: 25 cm – 75 cm per year; dry season.

Discussion Question What temperature ranges and precipitation levels support the greatest diversity of plants and animals?

Aquatic Ecosystems Rivers Streams Lakes Ponds Freshwater ecosystems- include flowing and standing water, low or no salt. Rivers Streams Lakes Ponds

Wetlands Regions wet all or most of year Lie between solid land and water Very fertile ecosystems

Salt water ecosystems 95% of Earth’s water contains high concentration of salt, or high salinity.

Open oceans Divided into lighted and dark life zones Lighted-upper 200 m and home of plankton Dark-below 200 m where animal feed on material that floats down or prey on each other.

Coral reefs Diverse and fragile ecosystems formed from coral shells of calcium carbonate

Seashores Along coastlines Intertidal zone- covered with water at high tide and exposed to air at low tide. Drastic changes in temperature, moisture, salinity, and wave action.

Estuaries Where a river meets an ocean; called bays, lagoons, harbors, inlets, sounds. Rich in nutrients Changing mixture of salt water and freshwater.

Discussion Question What is the general relationship between sunlight and aquatic life?