allows for a a fairly accurate population estimation when direct counts are impossible. Less harmful to most species Accuracy doesn't depend on the assessment of avaible habitat The reliability can be affected by... Mixing in the population Immigration/ emigration Diseases the size of the marked and recaptured samples Predators On small, slow moving organisms who are easy to capture/gather together. example: snails On large, quick moving organisms who are hard to capture/gather together example: turkey vulturesBenfits: Drawbacks: Most Effective Least Effective N = [(n1 x n2)/m2] THE LINCOLN INDEX Count how many the of organism you are investigating there are. Put non toxic and non conspicuous markings on the organisms you counted. Put the organisms back into their population Wait 7-10 days to intermingle with the population again. Gather a new Sample Count how many of the organism are in the new sample, then count the number of the organism that had the marking from the last sample within this new sample Insert the orginal sample number, the second sample number, and the number recaptured into the equation Steps: 18.104.22.168.5.6.7.N1= the first sample number N2= the second sample number M2= number recaptured
D = 1-(En(n-1)/N(N-1)) THE SIMPSON'S DIVERSITY INDEX Add the individual species populations to get N . Determine N × (N - 1) . Work out n × (n - 1) for each species, where n is the number of individuals in each species. Sum all the values in step 3. Divide the sum obtained in step 4 by the value obtained in step 22.214.171.124.4.5.
SWEEP NETS USED TO COLLECT DATA TO MONITOR ALFALFA PESTS WHEN ALFALFA PLANTS GROW TO A CERTAIN HIGHT. OR FOR ANY PLANTS TO COLLECT PESTS. BENEFITS- SPEEDY AND SIMPLE TO USE. ALLOWS FOR A COLLECTION OF DIVERSE SPECIES OF BUGS TO STUDY THAT ARE FOUND ON PLANTS LIMITATIONS- NOT GOOD AT SAMPLING SHORT PLANTS LIKE GRASS AND ONCE THE PLANT REACHES OVER 30CM YOU START TO MISS ALOT OF THE INSECTS AS THE NET DOES NOT REACH THAT FAR MOST EFFECTIVE- SWING THE NET IN A 180 ARC SO THAT THE NET RIM STRIKES THE TOP 6-8 INCHES OF THE PLANT LEAST EFFECTIVE- NOT KEEPING THE NET PARALLEL TO THE GROUND