Environmental Sciences Course Biomes and Biodiversity

Terrestrial Biomes Aquatic Ecosystems Biodiversity and Species Definitions - Benefits of Biodiversity - Threats to Biodiversity Human Caused Reductions Biodiversity Protection University Of Palestine ENVI0052 Outline

University Of Palestine ENVI0053 BIOMES Biomes Areas sharing similar climate, topographic and soil conditions, and roughly comparable communities. Defined according to the prevailing plants Temperature and Precipitation are among the most important determinants in biome distribution.

University Of Palestine ENVI0054 BIOMES

University Of Palestine ENVI0055 World Biomes

University Of Palestine ENVI0056 Of the most important biomes on earth: Deserts Grasslands Tundra Mediterranean Tropical Moist Forests Wetlands

Deserts Characterized by low moisture levels and precipitation that is infrequent and unpredictable from year to year. Wide daily and seasonal temperature fluctuations. Soils are easily disturbed by human activities, and slow to recover. Plants exhibit water conservation characteristics. University Of Palestine ENVI0057

8 Grasslands Communities of grasses, seasonal herbaceous flowering plants, and open savannas. Few trees due to inadequate rainfall. Large daily and seasonal temperature fluctuations. Frequent grass fires. A habitat for roaming herds of ungulates.

University Of Palestine ENVI0059 Tundra Short growing season. Cold, harsh winters. Water locked up much of the year. Most animals migrate south or downhill in winter. Low biological productivity, low diversity, and low resilience.

University Of Palestine ENVI00510 Tundra

University Of Palestine ENVI00511 Mediterranean Hot, dry summers and cool, moist winters. Receive their rainfall during the winter months Dominated with small, leathery, waxy leaves. Landscape commonly experiences fires.

University Of Palestine ENVI00512 Tropical Moist Forests Cloud Forests - High mountains with heavy fog and mist. Tropical Rainforests - More than 200 cm annual rainfall with warm-hot temperatures year-round. - Rapid decomposition and nutrient cycling. - Thick acidic soil.

University Of Palestine ENVI00513 Wetlands Land surface is saturated or covered with water at least part of the year. 1.Swamps -Wetlands with trees. 2.Marshes - Wetlands without trees. 3.Bogs and Fens - Waterlogged soils that tend to accumulate peat. Water usually shallow enough to allow full sunlight penetration. Trap and filter water, and store runoff.

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University Of Palestine ENVI00517 Aquatic Ecosystems Freshwater Ecosystems Marine Ecosystems

University Of Palestine ENVI00518 Freshwater Ecosystems Include standing waters of ponds and lakes, as well as flowing waters of rivers and streams. Cover relatively little total area, but biologically distinctive. Extremely varied due to individual site conditions

19 Critical Aquatic Characteristics Dissolved Substances Suspended Matter Depth Temperature Flow Rate Bottom Characteristics Internal Convective Currents Connectivity to Other Aquatic Ecosystems University Of Palestine ENVI005

20 Water Gradients

University Of Palestine ENVI00521 Marine Ecosystems Marine ecosystems have as much variability as those on land. Food webs and communities off-shore are intricately connected to those onshore. Coral Reefs - Accumulated calcareous skeletons of colonial organisms (coral). Depth limited by light penetration. Among most endangered communities.

University Of Palestine ENVI00522 BIODIVERSITY Biodiversity - Variety of living things. Genetic Diversity - Measures variety of different versions of same genes. Species Diversity - Measures number of different kinds of organisms within a community. Ecological Diversity - Measures richness and complexity of a community.

University Of Palestine ENVI00523 BENEFITS OF BIODIVERSITY 1.Food As many as 80,000 edible wild plant species could be utilized by humans. 2.Drugs and Medicines More than half of all medicines contain some natural product. Medicine companies actively prospect tropical countries for products.

University Of Palestine ENVI00524 Benefits of Biodiversity 3.Ecological Benefits Soil formation, waste disposal, air and water purification, nutrient cycling, solar energy absorption, and biogeochemical and hydrological cycles all depend on biodiversity.

University Of Palestine ENVI00525 Benefits of Biodiversity 4. Aesthetic and Cultural Benefits Cultural diversity inextricably linked to biodiversity. Ecotourism can be an important form of sustainable economic development.

University Of Palestine ENVI00526 THREATS TO BIODIVERSITY Extinction - Elimination of a species. A species becomes extinct when the last existing member of that species dies 1.Normal Process In undisturbed ecosystems, background rate appears to be one species per decade. 2.Human impacts: human have accelerated extinction rate, causing perhaps hundreds to thousands of extinctions annually.

University Of Palestine ENVI00527 Natural Causes of Extinction -Fossil Record suggests more than 99% of all species ever in existence are now extinct. -Most went extinct before humans arrived. -Natural crisis and disasters are a major causative for extinction

University Of Palestine ENVI00528 Human-Caused Reductions in Biodiversity Habitat Destruction Most simply, any species that is unable to survive or reproduce in its environment, and unable to move to a new environment where it can do so, dies out and becomes extinct.

University Of Palestine ENVI00529 Human-Caused Reductions in Biodiversity Some surveys predict that up to 20 percent of all living populations could become extinct within 30 years (by 2028). Human activities: 1.Hunting and Fishing 2.Pollution 3.Urbanization 4.Overconsumption of natural resources