An Introduction To Ecology Chapter 52

Ecology – study of interactions between organisms and environment. Consists of abiotic (nonliving; i.e. temperature, light, etc) and biotic (living) factors.

Population – group of individuals of same species living in an area. Community – all organisms of all species that live in an area. Ecosystem – above plus abiotic factors. Biosphere – sum of all ecosystems.

Distribution affected by temperature, water, sunlight, wind, and rocks and soil. Type of each will determine what can live there.

Temperature and water are biggest factors. Biomes – major types of ecosystems. Determined by proximity to equator, closeness to ocean, mountains, etc.

Aquatic biomes 2 types – marine and freshwater. Stratified vertically – photic zone (light) and aphotic zone (little light). Bottom of aquatic is benthos – food is detritus that falls from above.

Freshwater – close to shore – littoral zone. Open water – limnetic zone. A Lakes classified by nutrients – 1 eutrophic – shallow and nutrient- rich; 2 oligotrophic – deeper and nutrient-poor.

Oligotrophic lake

Eutrophic lake

B Wetlands – area covered with water; supports plants. C Estuaries – area where freshwater meets ocean. Intertidal zone – land meets water. D Coral reefs – dominated by coral.

Wetlands

Estuary

Coral Reef

E Oceanic pelagic biome – away from shore. Abyssal zone – lowest part of benthos; deep-sea hydrothermal vents help chemoautotrophic organisms.

Abyssal zone

Terrestrial biomes Defined vertically from the canopy at top to the permafrost at the bottom. A Tropical forest – little light reaches ground because of deep canopy. Rainfall determines life in area.

Tropical Forest In Madagascar

B Savanna – scattered trees and grasses. Fire helps increase diversity. Has rainy season. C Temperate grassland – seasonal drought, fires prevent tree growth. Most used for farming.

Savanna

Grasslands

D Deserts – sparse rain, some are cold. Plants have structures to allow survival (i.e. water storage, alternative forms of photosynthesis) E Chaparral – evergreen shrub; long, hot, dry summers with fires.

Desert

Chaparral

F Temperate deciduous forest – small mammals, leaves fall during autumn. G Taiga – cone-bearing trees, trees have needles. H Tundra – permafrost covers ground, low diversity.

Deciduous forest

Coniferous forest

Tundra