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Chapter 52 An Introduction to Ecology and the Biosphere Planet Earth • Chapter 52-Intro to Ecology and the Biosphere • Chapter 53-Population Ecology • Chapter 54-Community Ecology • Chapter 55-Ecosystems Ecology • The study of the interactions between organisms and their environment. Ecology • Integrates all areas of biological research and informs environmental decision making. Organisms • All living things. • Studied at many levels. Ecology - levels 1. Organismal Ecology 2. Population Ecology 3. Community Ecology 4. Ecosystem Ecology 5. Landscape Ecology 6. Global Ecology See page 1145 for definitions and examples Distribution of Species • Limited by interactions between organisms and the environment. 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. Salinity 4. Sunlight 5. Rocks and soil 6. Wind 7. 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). Salinity • Salt concentration affects osmotic potential and water balance. • Most aquatic organisms are limited by their ability to osmoregulate. 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. 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. Wind • Effects temperature and water conditions for many organisms. • May carry abrasive particles that limit plant growth by killing the growth points. • Can change dispersal of organisms 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. • Temperature, precipitation, sunlight and wind. Global Climate Patterns • Determined largely by solar energy and the movement of heat across the planet. Great Ocean Currents Wind Patterns 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. • If Earth’s axis of rotation suddenly became perpendicular to the plane of its orbit, the most predictable effect would be. a) No more night and day b) A big change in the length of the year c) A cooling of the equator d) A loss of seasonal variation at high latitudes e) The elimination of ocean currents • If Earth’s axis of rotation suddenly became perpendicular to the plane of its orbit, the most predictable effect would be. a) No more night and day b) A big change in the length of the year c) A cooling of the equator d) A loss of seasonal variation at high latitudes e) The elimination of ocean currents 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. Aquatic Biomes Fresh water Biomes • Have <1% salt concentration. • Strongly influenced by temperature and light. • Classification – based on water flow patterns. Freshwater Biomes • Lakes • Wetlands • Streams and Rivers • Estuaries See Pg 1159-1160 for details Marine Biomes • Cover 3/4 of the Earth's surface. • Average 3% salt. • Controlled by light and the distance to the shore. Marine Biomes 1. Intertidal 2. Oceanic Pelagic 3. Coral Reefs 4. Benthos See page 1161-1162 Light Zones • Photic - Enough light for Ps. Red light lost rapidly as depth increases. • Aphotic - Lacks enough light for Ps and depends on food made in photic zone for energy. Part of the most extensive biome on the planet. Estuaries • Where a freshwater river meets the ocean. • Salinity variable. • Very productive Biome. Coral Reef • Characterized by coral. • Found in shallow warm waters. • Very productive. • High species diversity. Benthos • Bottom area. • Usually fed by nutrients drifting down from upper levels. • Fairly rich in life. Biomes Controlled by: • Temperature • Water • Geography Terrestrial Biomes • Recognize all, but be able to describe features of 2-3 types. • See pages 1153-1156. Tropical Forests • Areas covered with dense growth of trees and vines. • Climate: – Warm temperatures. – Constant day length. – High water. Tropical Forests 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 or Northern Coniferous Forest • Coniferous trees dominate. • Climate: – Long cold winters – Short wet summers – Long summer daylength Taiga or Northern Coniferous 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 Summary • Know what is involved with the study of “Ecology”. • Know the major factors of planet Earth that shape climate. • Know the major aquatic and terrestrial biomes and the factors that control them.