The biosphere

biosphere All organisms and the part of the Earth where they exist Hydrosphere: collection of Earth’s water bodies, ice, and water vapor Atmosphere: air blanketing Earth’s solid surface Geosphere: features of Earth’s surface-such as continents and the sea floor-and everything below Earth’s surface

Biotic and abiotic factors interact in the biosphere

climate Average long-term weather pattern of a region Microclimate: climate of a specific location within a larger area

Climate Temperature Moisture Most organisms are adapted to live within a particular range of temperatures and will not thrive outside of that range For example: the growing season of plants is primarily influenced by temperature Moisture All organisms require water On land, water can be scarce and rainfall often determines an area’s life-forms

Earth has three main climate zones Polar Tropical Temperate Influence of sunlight Air and water movement Landmasses Adaptations to climate

Earth has 6 major biomes

Biome A large region characterized by a specific type of climate and certain types of plant and animal communities

Tropical Rainforest biome Annual rainfall: 450 cm (180 in) Greatest number of species compared to any other biome May contain at least ½ all of the Earth’s species of terrestrial organisms (more than 2 million species) Infertile soils but high primary productivity

Grassland biomes Tropical grasslands Temperate grasslands Temperatures warm throughout the year Tall grasses, scattered trees and shrubs Hoofed animals Temperate grasslands Dry and warm during summer; snowy winters Short or tall grasses, depending on precipitation Many animals live below the surface to survive dry, windy conditions

Desert biome Annual rainfall: less than 25 cm (10in) each year The scarcity of water is the overriding factor influencing most biological processes in the desert The vegetation is characteristically sparse Most extensive in the interiors of continents

Temperate forest biomes Temperate Deciduous Forest Temperate Evergreen/Tropical Forest Relatively mild climates and plentiful rain Grow in areas with relatively warm summers, cold winters Annual rainfall: 75-250 cm (30-100 in) Cover much of the eastern USA Home to deer, bears, beavers, raccoons, etc. Found in other temperate areas Drier weather and different soil conditions favor the growth of evergreens Large portions of the southeastern and western USA have temperate evergreen forests Where conditions are even drier, forests give way to areas of dry shrubs, such as in the chaparral areas of coastal California and in the Mediterranean

Taiga biome Cold, wet climates promote the growth of coniferous forests Extends across vast areas of Eurasia and North America Winters are long and cold Most precipitation occurs in the summer Many large mammals, including herbivores such as elk, moose, deer and carnivores such as wolves, bears and lynxes live in the taiga

Tundra biome Between the taiga and the permanent ice surroundings of the North Pole is the open, boggy tundra Covers 1/5th of the Earth’s land surface Annual precipitation: less than 25 cm (10 in) Water is unavailable for most of the year because it is frozen The permafrost, or permanent ice, usually exists within 1 m (3 feet) of the surface Foxes, lemmings, owls, and caribou are among the inhabitants

Minor biomes Chaparral: biome characterized by hot, dry summers and cool, moist winters; also called Mediterranean shrub-land

Polar ice caps and mountains are not considered biomes Polar ice caps have no soil and no specific plant community Mountain climate, animals and plants change with elevation

Marine ecosystems The ocean can be divided into zones

MARINE ECOSYSTEMS Intertidal Zone: strip of land between high and low tide lines Neritic Zone: zone that extends from the intertidal zone out to the edge of the continental shelf Plankton: microscopic, free-floating organisms, which may be animals or protists Zooplankton: animal plankton Phytoplankton: photosynthetic microscopic protists, such as algae Bathyal Zone: zone of the ocean that extends from the edge of the neritic zone to the base of the continental shelf Abyssal Zone: depth of the ocean that lies below 2000 meters and is in complete darkness

Coastal waters contain unique habitats Coral reef: ocean habitat found in the shallow coastal waters in the tropical climate Kelp forest: ocean habitat that exists in cold, nutrient-rich shallow coastal waters, composed of large communities of kelp, a seaweed

Estuary characteristics Estuaries are dynamic environments where rivers flow into the ocean Estuary Characteristics Refuge for many species Spawning grounds Threats to Estuary Ecosystems Loss of habitat Coastal erosion

Freshwater Communities Freshwater ecosystems include moving and standing water Lakes, ponds, streams, and rivers cover only 2% of the Earth’s surface All freshwater habitats are strongly connected to terrestrial ones, with freshwater marshes and wetlands constituting intermediate habitats Many organisms are restricted to freshwater habitats including fish, plants, arthropods, mollusk, and other invertebrates

Freshwater Communities Littoral Zone A shallow zone in a freshwater habitat where light reached the bottom and nurtures plants Inhabitants: Aquatic plants, predatory insects, amphibians, small fish Limnetic Zone The area in a freshwater habitat that is away from the shore but still close to the surface Inhabitants: floating algae, zooplankton, fish

Freshwater Communities Profundal/Benthic Zone The zone in a freshwater habitat to which little sunlight penetrates Inhabitants: numerous bacteria, wormlike organisms that eat debris on the bottom Not all freshwater systems are deep enough to have a profundal zone

Wetlands Swamps, marshes and bogs Covered with a layer of water Contain a variety of water-tolerant plants Dynamic communities that support a diverse array of invertebrates, birds, and other animals One of the most productive ecosystems on Earth, exceeded only by coral reefs in diversity and concentration of species Key role in water storage basins that moderate flooding