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Chapter 56 The Biosphere. The study of the interactions between organisms and their environment. Ecology. Organisms. All living things. Studied at many levels. Ecology - levels. 1. Organismal Ecology 2. Population Ecology 3. Community Ecology 4. Ecosystem Ecology 5. Biosphere Ecology.
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The study of the interactions between organisms and their environment. Ecology
Organisms • All living things. • Studied at many levels.
Ecology - levels 1. Organismal Ecology 2. Population Ecology 3. Community Ecology 4. Ecosystem Ecology 5. Biosphere Ecology
Environment • Abiotic Factors: non-living factors. Ex: Temperature, Light, Water Nutrients • Biotic Factors: effect of other organisms. Ex: Competition, Predation
Abiotic Factors 1. Temperature 2. Water 3. Sunlight 4. Wind 5. Rocks and Soil 6. Disturbance
Temperature • Effects biological processes. • Ex: • Cold – cells will rupture if they expand while freezing. • Hot – many proteins denature above 45 oC. • Point – life can only exist over a fairly narrow temperature range.
Water • Review the properties of water from Chapter 3. • Cells must maintain a correct water potential (keep from exploding or drying out).
Sunlight • Provides energy for Ps, which drives most food webs. • Plants often compete for light because of shading or absorption of light by deep columns of water.
Wind • Effects temperature and water conditions for many organisms. • May carry abrasive particles that limit plant growth by killing the SAM areas.
Rocks and Soil • Physical structure, pH, mineral composition of rocks and soil limit where plants can grow. Ex. Se soils. • Plants limit what animals can be found in an area.
Disturbance • Disturbance is often an important part of an environment. • Allows organisms to re-colonize an area. • Ex: Fire Humans Wind
Climate • Shapes environments and what organisms can live in a particular area.
Climatic Factors • Solar Radiation and Latitude • Axis Tilt/Seasons • Air/Water Circulation Patterns
Solar Radiation and Latitude • Changes the amount of light and energy delivered per surface area.
Result • Poles: less light • Equator: more light • The unequal heating causes air and water to circulate.
Seasons • Caused by the Earth's tilt. • Day length changes over time. • Many organisms are restricted in range by how well they adapt to changing seasons.
Global Air Patterns • Air rises when heated, sinks when cools. • Zones of rising/sinking are created. • Earth's rotation causes zones to "twist”.
Result • Air circulation patterns. • Rainfall patterns. • rising air: wet areas • descending air: dry areas
Biomes • Broad geographical regions with characteristic communities of organisms.
Biomes Controlled by: • Temperature • Water • Geography
Tropical Forests • Areas covered with dense growth of trees and vines. • Climate: • Warm temperatures. • Constant day length. • High water.
Tropical Forests • Have the greatest diversity of species of any area on Earth. • Soil is usually very infertile. Most of the nutrients are in the plant life. • One of the most endangered Biomes.
Savanna • Grasslands with a few trees. • Climate with three growing seasons: • Cool and dry • Hot and dry • Warm and wet
Savanna • Rich in herbivores and predator species. • Only major biome not found on North America.
Desert • Characterized by plants adapted to dry growing conditions. • Climate: • Dry (<30cm/yr). • May be cold or hot. • Often found in areas of descending air masses. • Low productivity, but still fairly diverse in species.
Chaparral • Characterized by spiny evergreen shrubs. • Climate: • Mild rainy winters • Hot summers • Ex: Southern California
Chaparral • Maintained by fires. • Plants adapted to periodic fires by seeds or re-growing from the roots.
Temperate Grasslands • Grasses and other herbs are the dominant vegetation. • Climate: • Intermediate water • Relatively cold winters
Grasslands • Very productive for agriculture. (wheat, corn) • Need disturbance (fires) to keep trees out. • Come in several types: • Tall grass • Short grass
Temperate Forests • Deciduous trees dominate. • Climate: • Relatively high rain • Cold winters • Very little natural area left. • Good diversity of species.
Taiga • Coniferous trees dominate. • Climate: • Long cold winters • Short wet summers • Long summer daylength
Taiga or Boreal Forest • Relatively low species diversity. • Being logged at an alarming rate.
Tundra • Grasses and sedges dominate. • Climate: • Very cold and dry • Low light in winter
Tundra • Permafrost present. • Plants low in height. • Poor species diversity.
Altitude and Latitude • Mirror each other. Their Biomes are similar because the environments are similar. • Ex: Alpine = Tundra
Fresh water Biomes • Have <1% salt concentration. • Strongly influenced by temperature and light. • Classification – based on water flow patterns.