BIO.B.4 Ecology
Topic Summary for Biomes:
A biome is a group of terrestrial regional climate communities that covers a large area and is characterized by soil type, climate, and plant and animal life.
Terrestrial Biomes
In tropical rain forests, the tops of tall trees form a covering called the canopy. Shorter trees and vines form another layer called the understory. It is hot and wet all year.
Tropical dry forests are found in areas with alternating wet and dry seasons. The trees in these forests may be deciduous, meaning they shed their leaves during a particular season.
In a tropical grassland, grassy areas are spotted with isolated trees.
Deserts have less than 25 centimeters of precipitation annually.
Temperate grasslands have warm summers, cold winters, and deep soil.
Temperate woodlands and shrublands are large areas of grasses and wildflowers such as poppies interspersed with trees or shrubs.
Temperate forests are made up of deciduous and evergreen coniferous trees. Coniferous trees produce seed-bearing cones and most have waxy needles. Temperate forests have soils rich in humus, which forms from decaying leaves and makes soil fertile.
Northwestern coniferous forests have mild temperatures with cool, dry summers and abundant precipitation in fall, winter, and spring.
Boreal forests, or taiga, are dense forests of coniferous evergreens.
Tundra is characterized by permafrost, a layer of permanently frozen subsoil.
Aquatic Biomes
Aquatic ecosystems are determined mainly by the depth, flow, temperature, and amount of dissolved nutrients of the water.
The photic zone is the sunlit upper layer of water where photosynthesis can occur.
The aphotic zone is the dark lower layer where photosynthesis cannot occur.
The benthic zone is found on the bottoms of lakes, streams, and oceans. The organisms that live on the floor of a body of water are called benthos.
Freshwater ecosystems include flowing-water ecosystems, standing-water ecosystems, and freshwater wetlands. Plankton are common. They form the base of many aquatic food webs.
Estuaries are wetlands formed where rivers meet the sea. They contain a mixture of fresh and salt water. Most of the food produced in estuaries enters food webs as tiny pieces of organic matter, or detritus.
Marine ecosystems are found in the ocean.
The intertidal zone is the shallowest and closest to land. It is exposed to the rise and fall of tides each day.
The coastal ocean is the relatively shallow border of water that surrounds the continents.
The open ocean begins at the continental shelf and extends outward. The open ocean can be divided into the photic zone and the aphotic zone.
Topic Summary for Biomes:
A biome is a group of terrestrial regional climate communities that covers a large area and is characterized by soil type, climate, and plant and animal life.
Terrestrial Biomes
In tropical rain forests, the tops of tall trees form a covering called the canopy. Shorter trees and vines form another layer called the understory. It is hot and wet all year.
Tropical dry forests are found in areas with alternating wet and dry seasons. The trees in these forests may be deciduous, meaning they shed their leaves during a particular season.
In a tropical grassland, grassy areas are spotted with isolated trees.
Deserts have less than 25 centimeters of precipitation annually.
Temperate grasslands have warm summers, cold winters, and deep soil.
Temperate woodlands and shrublands are large areas of grasses and wildflowers such as poppies interspersed with trees or shrubs.
Temperate forests are made up of deciduous and evergreen coniferous trees. Coniferous trees produce seed-bearing cones and most have waxy needles. Temperate forests have soils rich in humus, which forms from decaying leaves and makes soil fertile.
Northwestern coniferous forests have mild temperatures with cool, dry summers and abundant precipitation in fall, winter, and spring.
Boreal forests, or taiga, are dense forests of coniferous evergreens.
Tundra is characterized by permafrost, a layer of permanently frozen subsoil.
Aquatic Biomes
Aquatic ecosystems are determined mainly by the depth, flow, temperature, and amount of dissolved nutrients of the water.
The photic zone is the sunlit upper layer of water where photosynthesis can occur.
The aphotic zone is the dark lower layer where photosynthesis cannot occur.
The benthic zone is found on the bottoms of lakes, streams, and oceans. The organisms that live on the floor of a body of water are called benthos.
Freshwater ecosystems include flowing-water ecosystems, standing-water ecosystems, and freshwater wetlands. Plankton are common. They form the base of many aquatic food webs.
Estuaries are wetlands formed where rivers meet the sea. They contain a mixture of fresh and salt water. Most of the food produced in estuaries enters food webs as tiny pieces of organic matter, or detritus.
Marine ecosystems are found in the ocean.
The intertidal zone is the shallowest and closest to land. It is exposed to the rise and fall of tides each day.
The coastal ocean is the relatively shallow border of water that surrounds the continents.
The open ocean begins at the continental shelf and extends outward. The open ocean can be divided into the photic zone and the aphotic zone.