Data from: Tritrophic interactions at a community level: effects of host-plant species quality on bird predation of caterpillars
| Main Authors: | Singer, Michael S., Farkas, Timothy E., Skorik, Christian M., Mooney, Kailen A. |
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| Format: | info dataset Journal |
| Terbitan: |
, 2011
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/4936649 |
Daftar Isi:
- Effects of plant traits on herbivore-carnivore interactions are well documented in component communities, but are not well understood at the level of large, complex communities. We report on a two-year field experiment testing mechanisms by which variation in food quality among eight temperate forest tree species alters avian suppression of an assemblage of dietary generalist caterpillars. Plant quality and bird effects varied dramatically among tree species; high quality plants yielded herbivores of 50% greater mass than those on low quality plants, and bird effects ranged from near zero to 97% reductions in caterpillar density. We also find evidence for two mechanisms linking host-plant quality to bird effects. Statistically controlling for caterpillar density, birds had relatively strong effects on the herbivores of low quality plants, as predicted by the slow-growth/high-mortality hypothesis. At the same time, caterpillar density increased with plant quality, and bird effects were density-dependent. Consequently, the net effect of birds was strongest on the herbivores of high quality plants, a dynamic we call the high-performance/high-mortality hypothesis. Host-plant quality thus changes highly generalized herbivore-carnivore interactions by two complementary but opposing mechanisms. These results highlight the inter-relatedness of plant-herbivore and herbivore-carnivore interactions, and thus the importance of a tritrophic perspective.
- Focal herbivore final mass 04-08This excel file contains data on the final mass of 7 focal lepidopteran species reared on the 8 focal tree species of this study. These data were collected over 5 years (2004-2008) from field-sampled caterpillars that were subsequently reared in the laboratory on wild-harvested leaves from the same tree species from which they were sampled. These data were analyzed to quantify variation in host-plant quality among the 8 tree species.Bird exclusion on gen caterpillars 08-09This 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.