Abstract
Environmental variation in moisture directly influences plant litter decomposition through effects on microbial activity, and indirectly via plant species traits. Whether the effects of moisture and plant species traits are mutually reinforcing or counteracting during decomposition are unknown. To disentangle the effects of moisture from the effects of species traits that vary with moisture, we decomposed leaf litter from 12 plant species in the willow family (Salicaceae) with different native habitat moisture preferences in paired mesic and wetland plots. We fit litter mass loss data to an exponential decomposition model and estimated the decay rate of the rapidly cycling litter fraction and size of the remaining fraction that decays at a rate approaching zero. Litter traits that covaried with moisture in the species’ native habitat significantly influenced the decomposition rate of the rapidly cycling litter fraction, but moisture in the decomposition environment did not. In contrast, for the slowly cycling litter fraction, litter traits that did not covary with moisture in the species’ native habitat and moisture in the decomposition environment were significant. Overall, the effects of moisture and plant species traits on litter decomposition were somewhat reinforcing along a hydrologic gradient that spanned mesic upland to wetland (but not permanently surface-saturated) plots. In this system, plant trait and moisture effects may lead to greater in situ decomposition rates of wetland species compared to upland species; however, plant traits that do not covary with moisture will also influence decomposition of the slowest cycling litter fraction.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 573-584 |
| Number of pages | 12 |
| Journal | Oecologia |
| Volume | 179 |
| Issue number | 2 |
| DOIs | |
| State | Published - Oct 22 2015 |
Bibliographical note
Funding Information:We thank Chris Buyarski, Carrie Gahr, MacKenzie Kelly, Michael Kempnich, Katie Kemmitt, Christine O’Connell, Kristen Peterson, Kristen Ross, Kelsey Thurow, and Michael Wells for assistance in the field and laboratory, and anonymous reviewers for comments on a previous draft of this manuscript. This material is based upon work supported by the Cedar Creek Long Term Ecological Research Program (NSF DEB-1234162), the National Science Foundation Graduate Research Fellowship under Grant No. 00039202, and the Florence Rothman Fellowship Fund in the University of Minnesota’s College of Biological Studies.
Publisher Copyright:
© 2015, Springer-Verlag Berlin Heidelberg.
Keywords
- Cedar Creek
- Decomposition
- Hydrologic gradient
- Plant traits
- Salicaceae