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Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter
Published on: March 12, 2013
Vertical heterogeneity in predation pressure in a temperate forest canopy
Kathleen R Aikens1, Laura L Timms, Christopher M Buddle
1Department of Natural Resource Sciences, McGill University , Ste-Anne-de-Bellevue, Quebec , Canada.
Peerj
|September 7, 2013
Summary
Forest canopy height affects arthropod survival. Predation pressure decreases with height, offering better refuge in upper canopy layers for diverse arthropod groups.
Area of Science:
- Ecology
- Forest Ecology
- Predator-Prey Dynamics
Background:
- Forest canopies present vertical gradients influencing predation.
- Predation pressure variation impacts refuge quality for arthropods.
- Understanding arthropod refuge requires examining canopy stratification.
Purpose of the Study:
- To determine if different forest canopy strata offer varying refuge to arthropod groups.
- To assess the influence of vertical stratification on predation pressure.
- To compare the refuge efficacy across different canopy heights.
Main Methods:
- Combined direct and indirect experimental approaches.
- Quantified avian predator impact using exclosure cages across canopy strata (understory to upper canopy).
- Investigated invertebrate predator effects using bait trials in the same strata.
Main Results:
- Excluding birds increased arthropod densities across all strata, though effects varied by taxon.
- Both avian and invertebrate predators exhibited similar predation pressure gradients.
- Highest predation pressure was in the understory, decreasing with increasing height.
Conclusions:
- The forest canopy is heterogeneous regarding arthropod refuge from natural enemies.
- Vertical stratification significantly influences predation pressure and refuge availability.
- Arthropod refuge quality varies with canopy height, with upper layers offering better protection.
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