Bird exclusion on gen caterpillars 08-09

This Excel file contains the data from a field experiment evaluating the effect of bird exclusion on the density of generalist caterpillar species. The experiment was conducted over a 3-week caterpillar sampling period period in each of 2 years (2008, 2009). 2008 included 2 additional weeks of sampling (1 and 5) and these were used to obtain an independent estimate of caterpillar density per tree species. The spatial design included 6 complete blocks of 8 tree species at each of 3 field sites in each year. Note that the block identity number at each site was not necessarily consistent from year, thus a unique block2 column is given to designate block identity. Density of generalist caterpillars was calculated for each branch or sapling, designated as bagged or unbagged to indicate the bird exclusion treatment. Density is calculated as the number of generalist caterpillars divided by the estimated total leaf area of the branch or sapling. Total leaf area was originally calculated in square cm, based on the the number of leaves multiplied by the average leaf area from a sample of approximately 10 leaves from each branch.