Bright blue marble floating in space Biomes & Ecology Chapter 50 Spheres of life Molecules Cells (Tissues Organ Organ systems) Organisms Populations Community all the organisms of all the species that inhabit a particular area Ecosystem Biosphere 1
Factors affecting distribution Distinct global & regional patterns in the distribution of organisms Terrestrial biomes 2
Aquatic biomes Ecology Scientific study of interactions between organisms & their environment these interactions determine the distribution & abundance of organisms 3
Environmental factors Abiotic factors non-living chemical & physical factors temperature light water nutrients Biotic factors living components animals plants Biotic factors Competitors Predators / Parasites Food sources % seaweed & role of 2 herbivores 4
Abiotic factors Climate prevailing weather conditions in an area temperature water sunlight wind rocks & soil Physical factors rocks & soil Effects of climate 5
Global climate patterns Largely determined by sunlight & Earth s movement in space Seasonal changes Angle of the earth s axis is responsible for seasonal variations on Earth 6
Global air circulation Microclimates Localized effects windward leeward desert 7
Zonation in lake What factors contribute to organism distribution? Fresh water Lakes Oligotrophic nutrient poor Eutrophic nutrient rich Rivers different community supported than in ponds & lakes 8
Marine zones Marine benthos coral reef intertidal 9
Tropical rainforest distribution: equatorial precipitation: very wet temperature: always warm characteristics: many plants & animals, thin soil Savanna distribution: equatorial precipitation: seasonal, dry season/wet season temperature: always warm characteristics: fire-adapted, drought tolerant plants; herbivores; fertile soil 10
Desert distribution: 30 N & S latitude band precipitation: almost temperature: variable daily & seasonally, hot & cold characteristics: sparse vegetation & animals, cacti, succulents, drought tolerant, reptiles, insects, rodents, birds Chaparral distribution: coastal mid-latitude precipitation: seasonal, dry summer/rainy winter temperature: hot summer/cool winter characteristics: scrubby vegetation, drought-adapted, fireadapted, herbivores, amphibians, birds, insects 11
Temperate Grassland distribution: mid-latitudes, mid-continents precipitation: seasonal, dry season/wet season temperature: cold winters/hot summers characteristics: prairie grasses, fire-adapted, drought tolerant plants; many herbivores; deep, fertile soil Temperate Deciduous Forest distribution: mid-latitude, northern hemisphere precipitation: adequate, summer rains, winter snow temperature: moderate warm summer/cool winter characteristics: many mammals, insects, birds, etc.; deciduous trees; fertile soils 12
Coniferous Forest (Taiga) distribution: high-latitude, northern hemisphere precipitation: adequate to dry (temperate rain forest on coast) temperature: cool year round characteristics: conifers; diverse mammals, birds, insects, etc. Arctic Tundra distribution: arctic, high-latitude, northern hemisphere precipitation: dry temperature: cold year round characteristics: permafrost, lichens & mosses, migrating animals & resident herbivores 13
Alpine Tundra distribution: high elevation at all latitudes precipitation: dry temperature: cold year round characteristics: permafrost, lichens, mosses, grasses; migrating animals & resident herbivores Community Group of species living close enough together for potential interaction inter-species interactions competition (-/-) predation / parasitism (-/+) mutualism(+/+) commensalism (+/0) 14
Niche An organism s niche is its role in the environment Ecosystem Community of organisms plus the abiotic factors that exist in a certain area 15
Impact of ecology as a science Ecology provides a scientific context for evaluating environmental issues Rachel Carson, in 1962, in her book, Silent Spring, warned that use of pesticides such as DDT was causing population declines in many non-target organisms Learning from mistakes Introduced species transplanted species often explode to occupy a new area non-native species out-compete native species lack of competitors & predators reducing diversity examples African honeybee zebra mussel purple loosestrife 16
Zebra mussel Purple loosestrife 17
Purple loosestrife Purple loosestrife Non-native species out-compete native species lack of competitors & predators reducing diversity causing loss of food & nesting sites for animals 1968 1978 18