@article {KNZ002006, title = {Plant phylogenetic history explains in-stream decomposition at a global scale}, journal = {Journal of Ecology}, volume = {108}, year = {2020}, pages = {17-35}, abstract = {

\ \ \  1. Evolutionary history and adaptation to climate shape plant traits. Some include leaf traits that influence litter quality. Thus, evolutionary history should affect litter decomposition, a crucial ecosystem process. In addition, litter decomposition is directly influenced by climate. We consequently expect plant phylogeny, adaptation and climate to jointly influence litter decomposition. These effects and their interactions have yet to be untangled at a global scale.
\ \ \  2. Here we present an analysis of variation in litter decomposition rates in rivers and streams across 285 published studies for 239 species (from ferns to angiosperms) distributed at 494 locations world-wide. We estimated the relative contributions of climatic conditions and phylogenetic heritage on litter decomposition rates, partitioning phylogenetic from climatic effects at the site and species levels using phylogenetic eigenvector analysis and phylogenetic linear mixed models. In addition, we modelled transitions in decomposition rates under a suite of multiple adaptive-regime Ornstein\–Uhlenbeck models to test the hypothesis that natural selection has shaped clade-level litter decomposition rates.
\ \ \  3. Leaf litter decomposition rate exhibited a significant phylogenetic signal. Modelling decomposition rate as a function of location, climatic niche and phylogeny consistently recovered phylogeny alone as one of the top models in species-level analyses. Since many previous studies have focused on the same species across many locations, we also conducted analyses at the species \× site level. Both phylogenetic and climatic factors were favoured in models of this analysis, but the single most important predictor for angiosperms and for all taxa analysed together was phylogeny alone.
\ \ \  4. Synthesis. For plant species distributed globally at nearly 500 locations we found that plant phylogenetic history is a critically important predictor of litter decomposition rate in rivers and streams, explaining more of the variance in decomposition than site or climatic regime. Thus, our study demonstrates the influence of evolutionary history on suites of plant traits that shape a key ecosystem process.

}, keywords = {LTER-KNZ}, issn = {0022-0477}, doi = {10.1111/1365-2745.13262}, url = {https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1365-2745.13262}, author = {LeRoy, Carri J. and Hipp, Andrew L. and Lueders, Kate and Follstad Shah, Jennifer J. and Kominoski, John S. and Ard{\'o}n, Marcelo and W. K. Dodds and Gessner, Mark O. and Griffiths, Natalie A. and Lecerf, Antoine and Manning, David W. P. and Sinsabaugh, Robert L. and Webster, Jack R.}, editor = {Wardle, David} } @article {KNZ001810, title = {Global synthesis of the temperature sensitivity of leaf litter breakdown in streams and rivers}, journal = {Global Change Biology}, volume = {23}, year = {2017}, pages = {3064-3075}, abstract = {

Streams and rivers are important conduits of terrestrially derived carbon (C) to atmospheric and marine reservoirs. Leaf litter breakdown rates are expected to increase as water temperatures rise in response to climate change. The magnitude of increase in breakdown rates is uncertain, given differences in litter quality and microbial and detritivore community responses to temperature, factors that can influence the apparent temperature sensitivity of breakdown and the relative proportion of C lost to the atmosphere vs. stored or transported downstream. Here, we synthesized 1025 records of litter breakdown in streams and rivers to quantify its temperature sensitivity, as measured by the activation energy (Ea, in eV). Temperature sensitivity of litter breakdown varied among twelve plant genera for which Ea could be calculated. Higher values of Ea were correlated with lower-quality litter, but these correlations were influenced by a single, N-fixing genus (Alnus). Ea values converged when genera were classified into three breakdown rate categories, potentially due to continual water availability in streams and rivers modulating the influence of leaf chemistry on breakdown. Across all data representing 85 plant genera, the Ea was 0.34 \± 0.04 eV, or approximately half the value (0.65 eV) predicted by metabolic theory. Our results indicate that average breakdown rates may increase by 5\–21\% with a 1\–4 \°C rise in water temperature, rather than a 10\–45\% increase expected, according to metabolic theory. Differential warming of tropical and temperate biomes could result in a similar proportional increase in breakdown rates, despite variation in Ea values for these regions (0.75 \± 0.13 eV and 0.27 \± 0.05 eV, respectively). The relative proportions of gaseous C loss and organic matter transport downstream should not change with rising temperature given that Ea values for breakdown mediated by microbes alone and microbes plus detritivores were similar at the global scale.

}, keywords = {LTER-KNZ}, doi = {10.1111/gcb.13609}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13609}, author = {Follstad-Shah, J.J. and Kominoski, John S. and Ard{\'o}n, Marcelo and W. K. Dodds and Gessner, Mark O. and Griffiths, Natalie A. and Hawkins, Charles P. and Johnson, Sherri L. and Lecerf, Antoine and LeRoy, Carri J. and Manning, David W. P. and Rosemond, Amy D. and Sinsabaugh, Robert L. and Swan, Christopher M. and Webster, Jackson R. and Lydia H. Zeglin} }