Abstract
The decomposition of leaf litter constitutes a major pathway of carbon and nutrient cycling in terrestrial ecosystems. Though it is well established that litter decomposition varies among species, most leaf litter decomposes not alone, but in mixture with litter from heterospecifics. The consequences of this mixing, and of the role of multiple dimensions of plant biodiversity, for litter decomposition are ambiguous, with past research suggesting that mixing diverse litter can speed up, slow down, or have no effect on decomposition. Furthermore, different chemical constituents of litter decompose at different rates, and the consequences of diversity for each of these rates are not completely understood. We created litterbags corresponding to 49 different litter mixtures ranging from one to 12 temperate forest species and allowed them to decompose over 2 yr in a common garden in temperate eastern Minnesota, USA. Following collections at 2, 4, 12, and 24 months, we assessed total mass loss and changes in four classes of litter carbon (soluble cell contents, hemicellulose and bound proteins, cellulose, and lignin/acid unhydrolyzable recalcitrants). Species varied in litter decomposition rate (losing from 8% to 41% of total mass) and they lost soluble cell contents (up to 64% of ash-free mass) and hemicellulose and bound proteins (69%) much more rapidly over 2 yr than they lost cellulose (40%) and acid-unhydrolyzable residues (12%). A variety of macro- and micronutrients supported litter decomposition, with calcium, in particular, promoting it. In mixtures of litter from 2, 5, or 12 species, neither species richness nor phylogenetic diversity was associated with deviations from expected decomposition rates based on monocultures. Yet more functionally diverse litter mixtures lost labile carbon (soluble cell contents and hemicellulose) significantly more slowly than expected. This novel finding of the effect of litter diversity not on total litter decomposition, but on the decomposition of a particular class of litter compounds elucidates potential consequences of biodiversity for cycling of nutrients and energy in forest ecosystems.
| Original language | English (US) |
|---|---|
| Article number | e01407 |
| Journal | Ecological Monographs |
| Volume | 90 |
| Issue number | 3 |
| DOIs | |
| State | Published - Aug 1 2020 |
Bibliographical note
Funding Information:All authors conceived of and designed the experiment and contributed to data analysis and writing. J. J. Grossman conducted field and laboratory work and wrote the first draft of the manuscript. This work was supported by the U.S. National Science Foundation Long-Term Ecological Research (DEB-0620652 and DEB-1234162) and Dimensions of Biodiversity (DEB-1342872) Programs. J. J. Grossman was supported by a Doctoral Dissertation Fellowship from the University of Minnesota; fellowships from the Crosby, Rothman, Wilkie, Anderson, and Dayton Funds and by the department of Ecology, Evolution, and Behavior; and a visiting fellowship at the Arnold Arboretum of Harvard University. The authors wish to thank Charlotte Riggs, Xiaojing Wei, Hanna Dort, Ada Breitenbucher, Aspen Ward, Marcela Sofía Vaca Sánchez, Allen J. Butterfield, ZhaaZhaawaanong Greensky, Silvia Ecaterina García Jain, Cathleen Nguyen, Chris Buyarksi, Rachel Baumann Manzo, Ben Grossman, and Jill Herman for assistance with field and laboratory procedures. Rebecca Montgomery and Peter Reich both contributed to the design and execution of the FAB experiment, upon which the work reported here was based.
Funding Information:
All authors conceived of and designed the experiment and contributed to data analysis and writing. J. J. Grossman conducted field and laboratory work and wrote the first draft of the manuscript. This work was supported by the U.S. National Science Foundation Long‐Term Ecological Research (DEB‐0620652 and DEB‐1234162) and Dimensions of Biodiversity (DEB‐1342872) Programs. J. J. Grossman was supported by a Doctoral Dissertation Fellowship from the University of Minnesota; fellowships from the Crosby, Rothman, Wilkie, Anderson, and Dayton Funds and by the department of Ecology, Evolution, and Behavior; and a visiting fellowship at the Arnold Arboretum of Harvard University. The authors wish to thank Charlotte Riggs, Xiaojing Wei, Hanna Dort, Ada Breitenbucher, Aspen Ward, Marcela Sofía Vaca Sánchez, Allen J. Butterfield, ZhaaZhaawaanong Greensky, Silvia Ecaterina García Jain, Cathleen Nguyen, Chris Buyarksi, Rachel Baumann Manzo, Ben Grossman, and Jill Herman for assistance with field and laboratory procedures. Rebecca Montgomery and Peter Reich both contributed to the design and execution of the FAB experiment, upon which the work reported here was based.
Publisher Copyright:
© 2020 by the Ecological Society of America
Keywords
- IDENT
- biodiversity–ecosystem function
- cellulose
- dimensions of biodiversity
- functional diversity
- hemicellulose
- lignin
- litterbags
- phylogenetic diversity
- soluble cell contents
- tree diversity experiments