Article first published online: 20 MAY 2014
© 2014 The Authors. New Phytologist © 2014 New Phytologist Trust
Volume 203, Issue 3, pages 873–882, August 2014
How to Cite
Parsons, S. A., Congdon, R. A. and Lawler, I. R. (2014), Determinants of the pathways of litter chemical decomposition in a tropical region. New Phytologist, 203: 873–882. doi: 10.1111/nph.12852
- Issue published online: 10 JUL 2014
- Article first published online: 20 MAY 2014
- Manuscript Accepted: 15 APR 2014
- Manuscript Received: 10 MAR 2014
- James Cook University School of Marine and Tropical Biology
- JCU Research Advancement Program
- Marine and Tropical Science Research Facility
- Skyrail Rainforest Institute
- Earthwatch Institute
- chemical pathways;
- climate change;
- litter quality;
- plant litter;
- soil organic matter;
- tropical rainforest
- Litter decomposition is a key ecosystem process, yet our understanding of the drivers in chemical changes in leaves during decay is limited. Our aim was to determine the comparative differences (chemical divergence or convergence) between sites and the drivers of decay pathways.
- We used the litterbag method (‘in situ’ litterfall and standardized ‘control’ leaves) in Australian tropical rainforests and near-infrared spectrometry to show the chemical pathways during decomposition (c. 360 d; 12 control sites; 17 in situ sites). Chemical convergence/divergence was determined from spectral dissimilarity and quantile regression along a mass loss moving average. The influence of environment (climate and soil) and litter quality on decay pathways was determined between sites using correlation analysis.
- Throughout the region, litter composition in both treatments converged chemically during decay. However, divergent chemical pathways were shown for some samples/sites (especially with high initial lignin, phenolics and carbon (C), poor soil phosphorus (P), sodium (Na) and more seasonal moisture), and the diversity of decay residues increased with mass loss despite overall chemical convergence.
- Our study suggests that there is general chemical convergence of leaf litter during early decay, but also that divergent chemical pathways occur in locations that experience more intense seasonal drying, and contain species or conditions that promote poor-quality litter.