Environmental Chapter 3 Ecosystems

An ecosystem is all of the living and non-living things in a given area 2 factors – Biotic – all of the living things in an environment – ex. Insects, mice, plants Abiotic – physical factors in an environment – ex. Soil, air, water

Biomes A geographic area characterized by certain types of plants and animals A biome contains even smaller ecosystems ex. Rainforest biome contains tree-top ecosystems, river ecosystems etc.

Forest Biomes Develop where there is ample rainfall and moderate temperatures Three types Temperate deciduous forests Coniferous forests Rain forests

Temperate Deciduous Forest Biome Leaves change and fall every year We live in this biome Fairly broad leaves to absorb sun Average rainfall cm Average temperature Summer: 28 ºC Winter: 6ºC

Coniferous Forest Not much change between summer and winter Consists mainly of evergreen trees which have waxy needles to prevent water loss Seeds in cones Not a lot of plants grow in the under story because of limited light Average rainfall cm Average temperature Summer: 14°C Winter: -10° C

Tropical Rain Forest Most biologically diverse Most animals live in the canopy Soil nutrient poor Rain forest quickly disappearing through farming and clear-cutting, and development Average rainfall up to 400cm Average temperature Daytime:34°C Nighttime: 20°C

Rainforest Destruction Decrease in the world’s oxygen Increase in the world’s carbon dioxide Can lead to global warming Loss of species Loss of medicines

Temperate Grasslands Grasses and some flowering plants Seed-eating mammals and herbivores Biomass is manly underground, deep roots – this allows plants to live through grazing and fires Many fires Average rainfall 25-75cm Average temperature Summer 30°C Winter 0°C

Savannas Tropical grasslands Clumps of trees Deep roots Fluctuate between rainy season and drought Average rainfall 150 cm Average temperature Dry season: 34°C Wet season: 16°C

Deserts Plants are succulent and grow far apart to avoid competition for water Most animals are nocturnal to avoid heat from sun Many animals have ways of conserving water and cooling themselves Average rainfall less than 25cm Temperature can vary greatly between night and day Average temperature Summer: 38°C Winter: 7°C

Tundra No trees because cannot make deep roots Permafrost - frozen soil Soggy area because of poor drainage Average rainfall cm Average temperature Summer: 12°C Winter: -26°C

Marine Ecosystems Salty water Almost 75% of the earth is covered in salt water Phytoplankton are the most abundant producers (perform photosynthesis) Zooplankton feed on phytoplankton Both phytoplankton and zooplankton for the base of the ocean’s food web Ocean is divided into zones

Marine Zones Intertidal – where ocean meets land. For part of the day, this zone is above water Neritic zone – water is less than 200m deep. Plants and phytoplankton live here.

Oceanic – deep water zone 0-200m is zone where photosynthesis takes place Benthic – ocean bottom

Estuaries Place where fresh water from streams and rivers flows into oceans

Freshwater Ecosystems No salt A tributary is a smaller stream that meets with other tributaries to form bigger streams Rivers are where streams meet

Moving Freshwater Fast moving – steep, towards top of mountains, younger Animals have adaptations to avoid being swept away: grow on or under rocks etc

Slow moving - less steep, towards bottom of mountain, meanders (curves), older Biotic material and sediment deposit on the bottom forming “deltas” Eventually water flows into oceans

Still Waters Ponds and lakes Three zones Littoral zone – closest to land, plants, snails, larvae Open-water zone – extends from littoral zone and goes as deep as the light will reach, bass, trout, phytoplankton Deep-water zone – no light, beneath open water, catfish, fungus, feed on dead stuff that falls from above

Wetlands Water level is near or above the surface of the ground Absorb water during heavy rains Help replenish the water supply

Marshes Treeless wetlands

Swamp Wetlands where trees and vines grow Low-lying areas besides slow-moving rivers Flooded only part of the year