Presentation on theme: "Chapter 50 An Introduction to Ecology and the Biosphere."— Presentation transcript:
Chapter 50 An Introduction to Ecology and the Biosphere
Ecology u The study of the interactions between organisms and their environment.
Organisms u All living things. u Studied at many levels.
Ecology - levels 1. Organismal Ecology 2. Population Ecology 3. Community Ecology 4. Ecosystem Ecology 5. Biosphere Ecology
Environment u Abiotic Factors: non-living factors. Ex: Temperature, Light, Water Nutrients u 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 u Effects biological processes. u Ex: u Cold – cells will rupture if they expand while freezing. u Hot – many proteins denature above 45 o C. u Point – life can only exist over a fairly narrow temperature range.
Water u Review the properties of water from Chapter 3. u Cells must maintain a correct water potential (keep from exploding or drying out).
Sunlight u Provides energy for Photo- synthesis, which drives most food webs. u Plants often compete for light because of shading or absorption of light by deep columns of water.
Wind u Effects temperature and water conditions for many organisms. u May carry abrasive particles that limit plant growth by killing the SAM areas.
Rocks and Soil u Physical structure, pH, mineral composition of rocks and soil limit where plants can grow. Ex. Se soils. u Plants limit what animals can be found in an area.
Disturbance u Disturbance is often an important part of an environment. u Allows organisms to re-colonize an area. u Ex: Fire Humans Wind
Climate u Shapes environments and what organisms can live in a particular area.
Climatic Factors u Solar Radiation and Latitude u Axis Tilt/Seasons u Air/Water Circulation Patterns
Solar Radiation and Latitude u Changes the amount of light and energy delivered per surface area.
Savanna u Rich in herbivores and predator species. u Only major biome not found on North America.
Desert u Characterized by plants adapted to dry growing conditions. u Climate: u Dry (<30cm/yr). u May be cold or hot. u Often found in areas of descending air masses. u Low productivity, but still fairly diverse in species.
Light Zones u Photic - Enough light for Photo- synthesis. Red light lost rapidly as depth increases. u Aphotic - Lacks enough light for Photosynthesis and depends on food made in photic zone for energy. Part of the most extensive biome on the planet.