- Authors:
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Publication Date:
- NSF-PAR ID:
- 10355907
- Journal Name:
- Proceedings of the Royal Society B: Biological Sciences
- Volume:
- 289
- Issue:
- 1969
- ISSN:
- 0962-8452
- Sponsoring Org:
- National Science Foundation
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Abstract Understanding how biotic and abiotic interactions influence community assembly and composition is a fundamental goal in community ecology. Addressing this issue is particularly tractable along elevational gradients in tropical mountains that feature substantial abiotic gradients and rates of species turnover. We examined elevational patterns of avian community structure on 2 mountains in Malaysian Borneo to assess changes in the relative strength of biotic interactions and abiotic constraints. In particular, we used metrics based on (1) phylogenetic relatedness and (2) functional traits associated with both resource acquisition and tolerance of abiotic challenges to identify patterns and causes of elevational differences in community structure. High elevation communities were composed of more phylogenetically and functionally similar species than would be expected by chance. Resource acquisition traits, in particular, were clustered at high elevations, suggesting low resource and habitat diversity were important drivers of those communities. Traits typically associated with tolerance of cold temperatures and low atmospheric pressure showed no elevational patterns. All traits were neutral or overdispersed at low elevations suggesting an absence of strong abiotic filters or an increased influence of interspecific competition. However, relative bill size, which is important for thermoregulation, was larger in low elevation communities, suggesting abiotic factorsmore »
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Despite recent advances, we still do not understand how chronic nutrient enrichment impacts coastal plant community structure and function. We aimed to clarify such impacts by testing for differences in ecosystem productivity and multiple community metrics in response to fertilization. We established plots in 2015 consisting of control (C), nitrogen (N), phosphorus (P), and nitrogen + phosphorus (NP) treatments in a mid-Atlantic coastal grassland. In 2017 we collected aboveground biomass, functional traits, and species abundance for each plot. Our findings indicate a synergistic co-limitation, such that NP plots were more productive than all other treatments. A combination of traits responsible for competition and nutrient uptake (i.e., height and δ15N) caused trait-based divergence of N and NP plots from C and P plots. Functional trait-based composition patterns differed from species composition and lifeform abundance patterns, highlighting complexities of community response to nutrient enrichment. While trait-based functional alpha-diversity did not differ among nutrient treatments, it was positively correlated with biomass production, suggesting nutrients may impact functional alpha-diversity indirectly through increased productivity. Increased functional alpha-diversity could be a mechanism of co-existence emerging as productivity increases. These results have important implications for understanding how plant communities in low-productivity coastal systems are altered by fertilization.
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Background Assembly of species into communities following human disturbance (e.g., deforestation, fragmentation) may be governed by spatial (e.g., dispersal) or environmental (e.g., niche partitioning) mechanisms. Variation partitioning has been used to broadly disentangle spatial and environmental mechanisms, and approaches utilizing functional and phylogenetic characteristics of communities have been implemented to determine the relative importance of particular environmental (or niche-based) mechanisms. Nonetheless, few studies have integrated these quantitative approaches to comprehensively assess the relative importance of particular structuring processes.
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