Nutrient cycling in most terrestrial ecosystems is controlled by moisturedependent decomposer activity. In arid ecosystems, plant litter cycling exceeds rates predicted based on precipitation amounts, suggesting that additional factors are involved. Attempts to reveal these factors have focused on abiotic degradation, soil-litter mixing and alternative moisture sources. Our aim was to explore an additional hypothesis that macro-detritivores control litter cycling in deserts. We quantified the role different organisms play in clearing plant detritus from the desert surface, using litter baskets with different mesh sizes that allow selective entry of micro-, meso- or macrofauna. We also measured soil nutrient concentrations in increasing distances from the burrows of a highly abundant macro-detritivore, the desert isopod Hemilepistus reaumuri. Macro-detritivores controlled the clearing of plant litter in our field site. The highest rates of litter removal were measured during the hot and dry summer when isopod activity peaks and microbial activity is minimal. We also found substantial enrichment of inorganic nitrogen and phosphorous near isopod burrows. We conclude that burrowing macro-detritivores are important regulators of litter cycling in this arid ecosystem, providing a plausible general mechanism that explains the unexpectedly high rates of plant litter cycling in deserts.
|Original language||American English|
|Journal||Proceedings of the Royal Society B: Biological Sciences|
|State||Published - 6 Nov 2019|
Bibliographical noteFunding Information:
This article was supported by European Research Council (grant no. ERC-2013-StG-337023 (ECOSTRESS)) and by the Israel Science Foundation (grant no. ISF-1471/12) to D.H.
Data accessibility. Data available from the Dryad Digital Repository: https://doi.org/10.5061/dryad.6nq98f5 . Authors’ contributions. D.H. and N.S. conceived this study and designed the experiments. N.S. collected and analysed the data. All authors participated in writing the manuscript, contributed critically to the drafts and gave final approval for publication. Competing interests. We declare we have no competing interests. Funding. This article was supported by European Research Council (grant no. ERC-2013-StG-337023 (ECOSTRESS)) and by the Israel Science Foundation (grant no. ISF-1471/12) to D.H. Acknowledgements. We thank Mark Bradford for his most valuable advice, three anonymous reviewers who offered helpful suggestions for improving the manuscript, Rita Dumbur for laboratory assistance and Moshe Zaguri for preliminary data.
© 2019 The Authors.
- Above-belowground interactions
- Dryland decomposition conundrum
- Litter decomposition
- Terrestrial isopod