Learning Objectives

Define the terms species, habitat and biodiversityExplain how biodiversity may be considered at

different levels; habitat, species and geneticDDiscuss current estimates of global biodiversityExplain the importance of sampling in measuring

the biodiversity of a habitatDescribe how random samples can be taken

when measuring biodiversity

Success criteria

Understand biodiversity and how to sample plants and animals

Key Term DefinitionsSpecies

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

BiodiversityNumber and variety of living things to be found

in the world/ecosystem/habitat

BiodiversityBiodiversity can be considered at different

levelsHabitat

Range of habitats that different species live in

SpeciesNumber of different species and the

abundance of each species in an areaGenetic

Genetic variation between individuals of the same species (variation of alleles)

Global BiodiversityDiscuss current estimates of global biodiversityCatalogue of lifeCurrent estimate of known species:

1,7300,000Some scientist believe this is only 10% of

total. Why?Find new speciesEvolution and speciation are continuingSpecies becoming extinct

Only takes into account number of species not number of individuals or variation

SamplingImportant in measuring the biodiversity of

a habitatIndividuals too numerous to count all in

habitat e.g. bacteria, fungiSelect small portion of habitat to studyMultiply number of individuals found by

area

Measuring BiodiversityMethod 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 PlantsMeasure 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

TransectLine transect: along large habitat,

record plants touching line at intervals

Belt transect: move quadrat along line

Measuring Biodiversity: AnimalsNets sweeping the

ground

Trees: knock branches with stick and collect in plastic on floor

Measuring Biodiversity: AnimalsPitfall 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 humansProvide data to give assessments of

environmental impactAllow us to reduce our impact