The worldwide leaf economics spectrum

In hyperdiverse tropical forests, the key drivers of litter decomposition are poorly understood despite its crucial role in facilitating nutrient availability for plants and microbes. Selective logging is a pressing land use with potential for considerable impacts on plant–soil interactions, litter decomposition, and nutrient cycling. Here, in Borneo's tropical rainforests, we test the hypothesis that decomposition is driven by litter quality and that there is a significant “home‐field advantage,” that is positive interaction between local litter quality and land use. We determined mass loss of leaf litter, collected from selectively logged and old‐growth forest, in a fully factorial experimental design, using meshes that either allowed or precluded access by mesofauna. We measured leaf litter chemical composition before and after the experiment. Key soil chemical and biological properties and microclimatic conditions were measured as land‐use descriptors. We found that despite substantial differences in litter quality, the main driver of decomposition was land‐use type. Whilst inclusion of mesofauna accelerated decomposition, their effect was independent of land use and litter quality. Decomposition of all litters was slower in selectively logged forest than in old‐growth forest. However, there was significantly greater loss of nutrients from litter, especially phosphorus, in selectively logged forest. The analyses of several covariates detected minor microclimatic differences between land‐use types but no alterations in soil chemical properties or free‐living microbial composition. These results demonstrate that selective logging can significantly reduce litter decomposition in tropical rainforest with no evidence of a home‐field advantage. We show that loss of key limiting nutrients from litter (P & N) is greater in selectively logged forest. Overall, the findings hint at subtle differences in microclimate overriding litter quality that result in reduced decomposition rates in selectively logged forests and potentially affect biogeochemical nutrient cycling in the long term.

Section: Discussionmentioning

confidence: 99%

Land use not litter quality is a stronger driver of decomposition in hyperdiverse tropical forest

Both

Elias

Kritzler

et al. 2017

“…There is strong evidence for trade‐offs associated with leaf functioning, stem construction, plant hydraulics, and the division of reproductive effort into few large or many small seeds (Henery and Westoby 2001; Wright et al. 2004; Chave et al. 2009; Poorter et al.…”

Section: Introductionmentioning

confidence: 99%

Quantifying and understanding reproductive allocation schedules in plants

Wenk

Falster

2015

101

A plant's reproductive allocation (RA) schedule describes the fraction of surplus energy allocated to reproduction as it increases in size. While theorists use RA schedules as the connection between life history and energy allocation, little is known about RA schedules in real vegetation. Here we review what is known about RA schedules for perennial plants using studies either directly quantifying RA or that collected data from which the shape of an RA schedule can be inferred. We also briefly review theoretical models describing factors by which variation in RA may arise. We identified 34 studies from which aspects of an RA schedule could be inferred. Within those, RA schedules varied considerably across species: some species abruptly shift all resources from growth to reproduction; most others gradually shift resources into reproduction, but under a variety of graded schedules. Available data indicate the maximum fraction of energy allocated to production ranges from 0.1 to 1 and that shorter lived species tend to have higher initial RA and increase their RA more quickly than do longer‐lived species. Overall, our findings indicate, little data exist about RA schedules in perennial plants. Available data suggest a wide range of schedules across species. Collection of more data on RA schedules would enable a tighter integration between observation and a variety of models predicting optimal energy allocation, plant growth rates, and biogeochemical cycles.

“…The PCA axis 1 and the correlation results confirmed the trait trade‐offs between nutrient concentrations, photosynthetic rates, and construction cost in bryophytes (Shipley, Lechowicz, Wright, & Reich, 2006; Wang, Bao, Feng, & Lin, 2014; Wright et al., 2004). The high Chl mass , A mass , and nutrient photosynthetic use efficiencies of the Polytrichaceae in comparison with other species agree with previous research (Marschall & Proctor, 2004).…”

Section: Discussionmentioning

confidence: 99%

Comparisons of photosynthesis‐related traits of 27 abundant or subordinate bryophyte species in a subalpine old‐growth fir forest

Wang

Bader

Liu

et al. 2017

Bryophyte communities can exhibit similar structural and taxonomic diversity as vascular plant communities, just at a smaller scale. Whether the physiological diversity can be similarly diverse, and whether it can explain local abundance patterns is unknown, due to a lack of community‐wide studies of physiological traits. This study re‐analyzed data on photosynthesis‐related traits (including the nitrogen, phosphorus and chlorophyll concentrations, photosynthetic capacities, and photosynthetic nutrient use efficiencies) of 27 bryophyte species in a subalpine old‐growth fir forest on the eastern Tibetan Plateau. We explored differences between taxonomic groups and hypothesized that the most abundant bryophyte species had physiological advantages relative to other subdominant species. Principal component analysis (PCA) was used to summarize the differences among species and trait values of the most abundant and other co‐occurring subdominant species. Species from the Polytrichaceae were separated out on both PCA axes, indicating their high chlorophyll concentrations and photosynthetic capacities (axis 1) and relatively high‐light requirements (axis 2). Mniaceae species also had relatively high photosynthetic capacities, but their light saturation points were low. In contrast, Racomitrium joseph‐hookeri and Lepidozia reptans, two species with a high shoot mass per area, had high‐light requirements and low nutrient and chlorophyll concentrations and photosynthetic capacities. The nutrient concentrations, photosynthetic capacities, and photosynthetic nutrient use efficiencies of the most abundant bryophyte species did not differ from co‐occurring subdominant species. Our research confirms the links between the photosynthesis‐related traits and adaptation strategies of bryophytes. However, species relative abundance was not related to these traits.