Intro to Ecology the Biosphere Chapter 52 Ecology
Intro to Ecology & the Biosphere Chapter 52
Ecology • scientific study of the interactions between organisms and the environment • an organism’s environment includes: – abiotic (non-living) components – biotic (living) components) • focuses on 4 levels of biological organization: – populations – communities – ecosystems – biosphere
Subfields of Ecology • organismal ecology – how an organism′s structure, physiology, and behavior meet the challenges posed by the environment • population ecology – how factors affect the number of individuals of a particular species live in an area • community ecology – how interactions such as predation, competition, & disease, as well as abiotic factors like disturbance, affect community structure & organization
Subfields of Ecology cont. l ecosystem ecology l focuses on energy flow and chemical cycling among the various biotic and abiotic components l landscape ecology l deals with arrays of ecosystems & how they are arranged in a geographic region l focuses on the factors controlling exchanges of energy, materials, and organisms among the ecosystem patches making up a landscape or seascape
Global Distribution of Organisms l a major factor contributing to the global distribution of organisms is dispersal: l movement of individuals away from centers of high population density or from their area of origin l limits to distribution include: l accessibility of an area (ie: dispersal) l behavior (ie: habitat selection) l biotic factors (ie: predation, competition, parasitism, disease) l abiotic factors (ie: temperature, water, sunlight, wind, soil structure/nutrients, fire, oxygen, salinity, etc. )
Climate l major components: temperature, water, sunlight, & wind l temperature & water have a major influence on the distribution of organisms l climate patterns can be described on 2 scales: l macroclimate = patterns on the global, regional, & local level l microclimate = very fine patterns, such as those encountered by the community of organisms underneath a fallen log
Macroclimate • Earth′s global climate patterns are determined largely by the input of solar energy & the planet′s movement in space – the sun′s warming effect on the atmosphere, land, & water establishes the temperature variations, cycles of air movement, and evaporation of water that are responsible for dramatic latitudinal variations in climate • proximity to bodies of water, mountain ranges, & other topographic features affect regional & local climatic variations – contributes to the patchiness of the biosphere • changing angle of the sun over the course of the year also affects local environments
Sun Intensity: Latitude Variations
Sun Intensity: Seasonal Variations
Air Circulation & Precipitation Patterns
Wind Patterns
Water Moderates Climate warm summer day
Mountains Affect Rainfall
Microclimate • many features in the environment influence microclimates by casting shade, affecting evaporation from soil, & changing wind patterns
Biomes • major types of ecological associations that occupy broad geographic regions of land or water
Aquatic Biomes account for the largest part of the biosphere in terms of area • freshwater & marine –
Aquatic Biomes cont. • many aquatic biomes are physically & chemically stratified • communities are distributed according to depth of the water, degree of light penetration, distance from shore, and open water versus bottom
Terrestrial Biomes • because there are latitudinal patterns of climate over Earth′s surface, there also latitudinal patterns of biome distribution • the impact of climate on the distribution of organisms can be seen in a climograph
Terrestrial Biomes • most terrestrial biomes are named for major physical or climatic features and for their predominant vegetation – vertical stratification of vegetation provides many different habitats for animals – terrestrial biomes usually grade into each other, without sharp boundaries at an area called an ecotone
Major Terrestrial Biomes
AQUATIC BIOMES Distribution of life is affected by: • • • LIGHT Temperature Oxygen Salinity Turbulence
Zones in lake- affect distribution of organisms
FRESHWATER BIOMES Eutrophic Lake Oligotrophic Lake River
Wetlands (top) and estuaries (bottom)
Zonation in the marine environment
Examples of marine biomes CORAL REEF TIDE POOL: Intertidal DEEP SEA VENT: Benthos
Black smoker
The distribution of major terrestrial biomes
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 grassland
Temperate deciduous forest Distribution: mid-latitudes, northern hemisphere Precipitation: adequate; summer rains, winter snow Temperature: moderate warm summer, cool winter Characteristics: many mammals, insects, birds, etc. deciduous trees; fertile soil
Temperate deciduous forest
Coniferous forests 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.
Coniferous forests
Tundra Distribution: arctic, high-latitude, northern hemisphere Precipitation: dry Temperature: cold year round Characteristics: permafrost, lichens and mosses, migrating animals & resident herbivores
Tundra
Tropical forests Distribution: equatorial Precipitation: very wet Temperature: always warm Characteristics: many plants and animals, canopy; thin, poor soil
Tropical forests
Savanna Distribution: equatorial Precipitation: seasonal, dry season/wet season Temperature: always warm Characteristics: fire-adapted, drought tolerant plants; herbivores; fertile soil
Savanna
Deserts Distribution: 30 o N and S latitude band Precipitation: very little Temperature: variable daily and seasonal; hot and cold Characteristics: sparse vegetation and animals, cacti, succulents, drought-tolerant; reptiles, insects, rodents, birds
Deserts
Chaparral Distribution: coastal mid-latitude Precipitation: seasonal, dry summer/rainy winter Temperature: hot summer/cool winter Characteristics: scrubby vegetation, drought-adapted, fir adapted; herbivores, amphibians, birds, insects
Chaparral
Threats to Ecosystem Stability Introduced Alien and Invasive Species
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