Biology 1 Chapter 21 Ecosystems
Do Now • Which of the following shows the organizational level of a biome from the broadest category to the most specific category? • A. biome population community ecosystem organism • B. biome ecosystem community population organism • C. biome community ecosystem population organism • D. biome ecosystem population community organism
Biomes • Biomes-large climatic regions that contain a number of smaller but related ecosystems within them. • May exist in more than one location on Earth, but each location has a similar climate.
Terrestrial Biomes-Tundra • Tundra-cold and largely treeless • Permafrost-permanently frozen layer of soil under the surface • Small slow growing plants like grass, moss • Short growing season • Few nutrients in soil due to low temperatures that hinder decay
Tropical Forest • Tropical forest-occur near the equator • Stable temperatures • Abundant rainfall • Two seasons: One wet & one dry • Have the highest species richness of all biomes • Tropical dry forest-have long dry seasons during which the trees lose their leaves • Tropical rain forest-characterized by long wet seasons and tall trees and plants that grow year-round.
Competition for light is intense in a tropical rain forest. • Canopy-a continuous layer of treetops which shades the forest floor. • Jungle-dense growth found along riverbanks and in disrupted areas where sunlight can reach the forest floor. • Epiphytes-small plants that live on the branches of tall trees; produce their own food • Ex. Mosses, orchids, and bromeliads
Temperate Forest • Occur in eastern North America, western and central Europe, and northeastern Asia • Distinct seasons • Moderate climate • Characterized by the type of tree that is most common • Two Types: Deciduous and Coniferous
Temperate Deciduous Forest-lose all of their leaves in the fall and regrow them in the spring. • Have pronounced precipitation with precipitation unevenly distributed through the years. • Trees have broad, thin leaves with a large surface area • Large areas have been cut down for timber or cleared for human inhabitation.
Taiga-Forested biome dominated by coniferous trees • Also known as the boreal forest or temperate coniferous forest • Long winter with snow covers and insulates the ground, protecting tree roots. • Plants are adapted for long, cold winters, short summers, and nutrient-poor soil. • Waxy, needle-shaped leaves remain on the tree all winter long and adapt against water loss.
Grasslands • Dominated by a variety of grasses • Known by different names in different parts of the world • North America-Prairies • Asia-Steppes • South America-Pampas • Africa-Veldts
Temperate Grasslands-usually form in the interior of continents with rainfall patterns that make these areas too dry to support trees. • Have rich, fertile soil • Support large herds of grazing animals • Can survive repeated grazing and fires because the actively growing part of the plant is at or below the ground. • Many have been transformed into farmland
Savanna-tropical or temperate grasslands that have scattered deciduous trees and shrubs • Have more rainfall than deserts • Have alternating wet and dry seasons • Some trees shed their leaves during the dry season • Support large numbers of herbivores and carnivores
Chaparral-dominated by dense, spiny shrubs and scattered clumps of coniferous trees • Mild, rainy winters and hot, dry summers with periodic fires • Found mainly in coastal settings.
Desert-areas that receive an average of less than 10 inches of rainfall per year • Cold desert-hot in summer but cold in winter • Great Basin and Gobi Desert • Vegetation is sparse and consists of plants that have waxy coatings • Animals avoid heat of the day by hiding or burrowing
Do Now • Which choice below lists the biomes in order from lowest precipitation amounts to highest precipitation amounts? • A. desert, temperate deciduous forest, grasslands, tropical rainforest • B. grasslands, desert, tropical rainforest, temperate deciduous forest • C. desert, grasslands, temperate deciduous forest, tropical rainforest • D. grasslands, desert, temperate deciduous forest, tropical rainforest • Answer: C
Do Now • A pod of dolphins hunting and feeding on a school of fish is an example of • A. a community interaction. • B. a biome interaction. • C. a population interaction. • D. an ecosystem interaction. • Answer: A
Aquatic Ecosystems:Ocean Zones • Photic Zone-the part of the ocean that receives sunlight • Aphotic Zone-the zone where sunlight cannot penetrate • Zones relative to the ocean’s edges: • Intertidal • Neritic • Zonesrelative to the open ocean: • Pelagic-not near coast • Benthic-sea floor
Intertidal Zone-the area of shoreline that is twice daily covered by water during high tide and exposed to air during low tide.
Neritic Zone-Extends from the intertidal zone over the continental shelf and to relatively shallow water • The most productive zone in the ocean. • Upwelling-strong currents that carry nutrients from the ocean bottom and mix them with nutrients contained in runoff from land. • Plankton-communities of small organisms that drift with the ocean currents • Coral reefs-built by coral animals over long periods of time
Oceanic Zone-encompasses the deepest parts of the ocean • About half of the photosynthesis that occurs on Earth takes place in the oceanic zone
Estuary-occurs where freshwater rivers and streams flow into the sea • Ex. Bay, mud flat, mangrove swamp, salt marsh • Shallow water receives light, & rivers deposit large amounts of minerals • Contain Sphagnum moss
Freshwater Zones • Lakes and ponds are divided into two categories: • Eutrophic lakes-rich in organic matter and vegetation, so the waters are relatively murky. • Oligotrophic lakes-contain little organic matter and the bottom is usually sandy or rocky
River/stream-body of freshwater that flows down a gradient toward its mouth.
Freshwater wetlands-areas of land that are covered with fresh water for at least part of each year. • Most productive freshwater ecosystem • Important stopovers for migratory birds • Provide protection for spawning organisms. • Act as filters to clean pollutants out of the water • Act as flood control
Two types of wetlands: • Marshes-contain non-woody plants • Swamps-contain woody plants
Do Now • Which choice below lists the biomes in order from lowest average temperatures to highest average temperatures? • A. taiga, tropical rainforest, grasslands • B. taiga, temperate deciduous forest, savanna • C. tundra, grasslands, taiga • D. tundra, savanna, temperate deciduous forest • Answer: B