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Biodiversity. Learning Objectives. Understand biodiversity and how to sample plants and animals. Define the terms species , habitat and biodiversity Explain how biodiversity may be considered at different levels; habitat, species and genetic D
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Learning Objectives • Understand biodiversity and how to sample plants and animals • Define the terms species, habitat and biodiversity • Explain how biodiversity may be considered at different levels; habitat, species and genetic • D • Discuss current estimates of global biodiversity • Explain the importance of sampling in measuring the biodiversity of a habitat • Describe how random samples can be taken when measuring biodiversity Success criteria
Key Term Definitions • Species • A group of organisms whose members are similar to each other in morphology, physiology, biochemistry and behaviour; who can interbreed to produce fertile offspring • Habitat • Place where an organism or population lives • Biodiversity • Number and variety of living things to be found in the world/ecosystem/habitat
Biodiversity Biodiversity can be considered at different levels • Habitat • Range of habitats that different species live in • Species • Number of different species and the abundance of each species in an area • Genetic • Genetic variation between individuals of the same species (variation of alleles)
Global Biodiversity Discuss current estimates of global biodiversity • Catalogue of life • Current estimate of known species: 1,7300,000 • Some scientist believe this is only 10% of total. Why? • Find new species • Evolution and speciation are continuing • Species becoming extinct • Only takes into account number of species not number of individuals or variation
Sampling • Important in measuring the biodiversity of a habitat • Individuals too numerous to count all in habitat e.g. bacteria, fungi • Select small portion of habitat to study • Multiply number of individuals found by area
Measuring Biodiversity • Method for taking random samples • Take samples at regular distances across the habitat • Use random numbers generated by a computer (assign coordinates to habitat) • Select coordinates from a map of the area and use a GPS to find exact position in habitat • Number of samples depend on size of habitat and biodiversity (if comparing two habitats take same number in each) • Prepare table of results before start
Measuring Biodiversity: Small Plants • Measure percentage ground cover using a quadrat or percentage cover using a point frame (10 needles, each plant touching a needle counts as 1% cover) • Can measure abundance on ACFOR (abundant, common, frequent, obvious, rare) scale, not able to do stats on this • Transect • Line transect: along large habitat, record plants touching line at intervals • Belt transect: move quadrat along line
Measuring Biodiversity: Animals • Nets sweeping the ground • Trees: knock branches with stick and collect in plastic on floor
Measuring Biodiversity: Animals • Pitfall trap collects small soil animals • Tullgren funnel collects small animals from leaf litter • Light trap collects flying insects
Why Measure Habitats? • Study to investigate effects of humans • Provide data to give assessments of environmental impact • Allow us to reduce our impact