Biodiversity

Learning Objectives Success criteria Understand biodiversity and how to sample plants and animals Success criteria 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

Key Term Definitions Species Habitat Biodiversity 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