Section 4 - Biomes and Aquatic Ecosystems
Ecosysystem: The community of organisms that live in a particular area, along with non living surroundings.
Biome: A group of land ecosystems with similar climates and organisms
Aquatic: Living or found in or near water
Biome: a group of land ecosystems with similar climates and organisms
Canopy: a leafy roof formed by tall trees
Understory: a layer of shorter plants that grow in the shade of a forest canopy
Desert: an area that receives less than 25 centimeters of precipitation per year.
Grassland: an area that is populated mostly by grasses and other non woody plants, receiving 25 to 75 centimeters of rain per year.
Savanna: a grassland close to the equator that receives as much as 120 centimeters of rain per year.
Deciduous Tree: trees that shed their leaves and grow new ones each year.
Coniferous Tree: a tree that produces the seeds in cones and that has needle-shaped leaves.
Tundra: an extremely cold, dry biome
Permafrost: soil that is frozen all year
Estuary: a habitat in which the freshwater of a river meets the salt water of an ocean
Intertidal Zone: the area between the highest high-tide line and lowest low-tide line
Neritic Zone: the region of shallow ocean water over the continental shelf
- There are 6 major biomes that most ecologists study:
- Rain Forest:
- Deciduous Forest:
- Boreal Forest:
- It is mostly the climate - temperature and precipitation - in an area that determines its biome.
- Why? It is the climate that limits the species of plants that can grow in an area. The species of plants determine the kinds of animal organism that live there.
Rain Forest: an area that receives plenty of rain in this biome, that creates a large variety of plant life.
- Two types:
- Temperate: plenty of rain however the temperature is moderate
- Tropical: plenty of rain with very high temperature
- Trees in the rain forest form several distinct layers:
- Canopy - is the leafy roof of the forest
- Understory - second layer of shorter trees and vines that grow well under the shade of the canopy
- Forest Floor - very dark, little sunlight reaches, so very little plant life.
Desert: an area that receives less than 25 centimeters of rain per year.
- The amount of evaporation exceeds the precipitation
- Organisms must adapt in order to survive in this biome.
Grassland Biomes: an area that is populated mostly by grasses and other non woody plants
- Receive more rain than desert - 25 to 75 cm of rain per year, but still not enough to for trees to grow. Commonly known as a prairie.
- Savanna - a grassland that receives up to 120cm rain per year. Scattered shrubs and small trees grow.
- Grasslands are home to many of the largest animals, i.e., elephants, bison, antelopes, zebras, rhinoceroses, giraffes, and kangaroos. They graze to maintain the grasslands (mow the lawns), and keep young trees and bushes from competing with the grass for water and sunlight.
- Receive enough rain, at least 50 centimeters of rain per year.
- Temperatures vary greatly - usually there are 4 seasons
- The growing season lasts about 5 to 6 months.
- The variety of plants create many different habitats.
- Winter time, many animals will hibernate (a reduced body activity similar to sleep where animals rely on stored fat in their bodies to survive).
Boreal (Taiga) Forest:
- Filled with spruce and fir trees
- Chilly fall air.
- Coniferous tree - trees that produce their seeds in cones and have leaves shaped like needles.
- Very cold winters.
- Coniferous trees have adapted to the cold climate and have developed thick, waxy needles that prevent water from evaporating.
- The food chain consists of animals that feed off the producers, coniferous tree seeds. I.e., squirrels, insects, and birds.
- Herbivores eat the tree bark and new shoots (the part of a new plant that is just beginning to grow above ground). I.e., hares, moose, and beavers.
- Predators include wolves, bears, owls, and lynxes.
- Extremely cold and dry.
- Very little precipitation, not much more than a desert.
- Most of the soil has been frozen for years.
- Permafrost is the term to describe frozen soil.
- During summertime, the frozen soil thaws at the top layer.
- Rainwater cannot soak into permafrost, therefore causing puddles and marshy areas.
- Producers include mosses, grasses, shrubs, and dwarf trees.
- Most plant growth occurs in the short summer.
- The sun does not set during midsummer North of the Arctic Circle.
- The animals include lots of insects in the summer, which birds migrate north in order to feed on them.
- Caribou, foxes, wolves and arctic hares grow thick fur coats in the harsh winter. Caribou feed of lichens (a small plant that grows on rocks and walls) that are under the snow. The wolves feed off of the weak Caribou in the herd.
Mountains & Ice:
- These are not part of any major biome.
- Mountain climate, plant and animal life can change from its base and its summit.
- For instance, the base might resemble grasslands, the middle sections might resemble deciduous and boreal forests, the summit might resemble a treeless tundra.
- Ice covers many parts of the lands on earth, i.e., Antarctica and Greenland.
- Organisms on ice covered land include penguins, polar bears, and leopard seals.