Environmental Sciences Course Biomes and Biodiversity

University Of Palestine ENVI005

Terrestrial BiomesAquatic EcosystemsBiodiversity and Species Definitions- Benefits of Biodiversity- Threats to Biodiversity Human Caused ReductionsBiodiversity ProtectionUniversity Of Palestine ENVI005 *Outline

University Of Palestine ENVI005

University Of Palestine ENVI005 *BIOMESBiomes Areas sharing similar climate, topographic and soil conditions, and roughly comparable communities. Defined according to the prevailing plantsTemperature and Precipitation are among the most important determinants in biome distribution.

University Of Palestine ENVI005

University Of Palestine ENVI005 *BIOMES

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University Of Palestine ENVI005 *World Biomes

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University Of Palestine ENVI005 *Of the most important biomes on earth:DesertsGrasslandsTundraMediterraneanTropical Moist ForestsWetlands

University Of Palestine ENVI005

DesertsCharacterized 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 ENVI005 *

University Of Palestine ENVI005

University Of Palestine ENVI005 *GrasslandsCommunities 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.

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University Of Palestine ENVI005 *TundraShort 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 ENVI005

University Of Palestine ENVI005 *Tundra

University Of Palestine ENVI005

University Of Palestine ENVI005 *MediterraneanHot, dry summers and cool, moist winters.Receive their rainfall during the winter monthsDominated with small, leathery, waxy leaves.Landscape commonly experiences fires.

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University Of Palestine ENVI005 *Tropical Moist ForestsCloud 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 ENVI005

University Of Palestine ENVI005 *WetlandsLand surface is saturated or covered with water at least part of the year.Swamps -Wetlands with trees.Marshes - Wetlands without trees.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.

University Of Palestine ENVI005

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University Of Palestine ENVI005

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University Of Palestine ENVI005

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University Of Palestine ENVI005 *Aquatic Ecosystems Freshwater Ecosystems

Marine Ecosystems

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University Of Palestine ENVI005 *Freshwater EcosystemsInclude 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

University Of Palestine ENVI005

*Critical Aquatic CharacteristicsDissolved SubstancesSuspended MatterDepthTemperatureFlow RateBottom CharacteristicsInternal Convective CurrentsConnectivity to Other Aquatic EcosystemsUniversity Of Palestine ENVI005

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University Of Palestine ENVI005 *Water Gradients

University Of Palestine ENVI005

University Of Palestine ENVI005 *Marine EcosystemsMarine 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 ENVI005

University Of Palestine ENVI005 *BIODIVERSITYBiodiversity - 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 ENVI005

University Of Palestine ENVI005 *BENEFITS OF BIODIVERSITYFoodAs many as 80,000 edible wild plant species could be utilized by humans.Drugs and MedicinesMore than half of all medicines contain some natural product. Medicine companies actively prospect tropical countries for products.

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University Of Palestine ENVI005 *Benefits of BiodiversityEcological Benefits Soil formation, waste disposal, air and water purification, nutrient cycling, solar energy absorption, and biogeochemical and hydrological cycles all depend on biodiversity.

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University Of Palestine ENVI005 *Benefits of Biodiversity4. Aesthetic and Cultural BenefitsCultural diversity inextricably linked to biodiversity.Ecotourism can be an important form of sustainable economic development.

University Of Palestine ENVI005

University Of Palestine ENVI005 *THREATS TO BIODIVERSITYExtinction - Elimination of a species.A species becomes extinct when the last existing member of that species diesNormal ProcessIn undisturbed ecosystems, background rate appears to be one species per decade.Human impacts: human have accelerated extinction rate, causing perhaps hundreds to thousands of extinctions annually.

University Of Palestine ENVI005

University Of Palestine ENVI005 *Natural Causes of ExtinctionFossil 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

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University Of Palestine ENVI005 *Human-Caused Reductions in BiodiversityHabitat DestructionMost 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 ENVI005

University Of Palestine ENVI005 *Human-Caused Reductions in BiodiversitySome surveys predict that up to 20 percent of all living populations could become extinct within 30 years (by 2028).

Human activities:Hunting and FishingPollutionUrbanizationOverconsumption of natural resources

University Of Palestine ENVI005

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