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3.1.Biodiversity
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Biodiversity What is all the fuss about?
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Biodiversity A measure of the biological richness of an area taking into account the number of species, community complexity and genetic variation within populations OR The amount of biological or living diversity per unit area. It includes the concepts of species diversity, habitat diversity and genetic diversity It is a measure of the species richness. This is a product of the number of different species and their relative abundance
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Each Species and Process…
Is key to the overall function of earth In general Diversity = Stability Biodiversity is Nature’s insurance policy against change The source of all natural capital for human use The way chemical materials are cycled and purified The end result of millions of years of evolution and irreplaceable
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Species Diversity Is the number of species or organisms per unit area found in different habitats of the planet.
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Species Diversity How many different species are there?
1.75 million known Many more unknown 5 – 50 million or more
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Biodiversity of Species
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Species Diversity Simpson’s diversity index is a good indicator
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Species Diversity The spread of individuals between species is more important than the total number of individuals in a habitat.
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Species diversity Product of two variables:
Species richness (number of species) Species evenness (relative proportions)
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Diversity includes High values of “D” suggests a stable and ancient site A low value of “D” could suggest pollution, recent colonization, or agricultural management Index normally used in studies of vegetation but can be applied to comparisons of diversity of any species
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Genetic Diversity Is the total number of genetic characteristics of a specific species within a population.
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Genetic Diversity larger population = greater genetic diversity
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Genetic Diversity Also referred to as genetic variability
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How does diversity exist?
Natural Selection = survival of the fittest Fitness = a measure of reproductive success If all individuals are variable And populations produce large numbers of offspring without increase in population size And resources are limited And traits are heritable
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Genetic Diversity Low genetic diversity and resulting poor sperm quality has made breeding and survivorship difficult for cheetahs. Moreover, only about 5% of cheetahs survive to adulthood
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Habitat Diversity Range of different habitat per unit are in an ecosystem or biome (niches per unit area). If habitat diversity is conserved than this usually leads to the conservation of species and genetic diversity.
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Habitat Diversity Variety of forests, deserts, grasslands, lakes, oceans, coral reefs, wetlands, and other biological communities, (niches per unit area).
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Habitat Diversity Most important range of niches
High genetic diversity More diverse species more genetic variation
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Why is biodiversity important?
Diversity = stability Nature’s insurance policy against change The source of all natural capital for human use The way chemical materials are cycled and purified The end result of millions of years of evolution and irreplaceable
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Biodiversity: Why should we care?
Diverse ecosystems are more stable and more healthy More resistant to damage from factors like climate change and spread of disease Provides important ecological services to humans Biodiversity is useful to us as humans Recreation Food Goods Medicine
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Ecological Services of Biodiversity
Flow of material, energy in the biosphere Photosynthesis Pollination Soil formation and maintenance Nutrient cycling Moderation of weather extremes Purification of air and water
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Important “stuff” From biodiversity
Food, fuel, ecosystems, species, fiber, lumber, paper…. 90% of all food crops 40% of all medicines and 85% of all antibiotics Willow Tree - Aspirin Pacific Yew – Taxol (cancer drug)
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Hot spots Biodiversity hotspot – a region with a high level of biodiversity that is under threat from human activities.
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The 19 Most Biodiverse countries in the world
The 19 Most Biodiverse countries in the world. What is the Problem with this?
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Biodiversity Hotspots need special consideration
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HOTSPOTS: These areas need emergency conservation attention
Especially rich in endemic plant and animal species (found nowhere else in the world) They cover on 1.4% of world land area Mostly tropical forests Contain 60% of identified terrestrial biodiversity 55% of all primates, 22% of all carnivores 1.1 billion people living in poverty near these sites $500 million annually would go far to ensure their preservation
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Critical and endangered
Projected Status of Biodiversity 1998–2018 Critical and endangered Threatened Stable or intact ANTARCTICA NORTH AMERICA EUROPE AFRICA ASIA SOUTH AUSTRALIA Pacific Ocean Antarctic Circle Tropic of Cancer Tropic of Capricorn Indian Atlantic 150° 90° 60°E 0° 30°W 120° 60° 30°N 30°S Arctic Circle
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Critics say that hotspots:
Focus on vascular plants and ignore animals. Do not represent total species diversity or richness. Focus on places that have already lost habitat, not those that are losing it. Do not consider genetic diversity. Do not consider the value of services: e.g. water resources.
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