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Abstract Plant ecological strategies are shaped by numerous functional traits and their trade‐offs. Trait network analysis enables testing hypotheses for the shifting of trait correlation architecture across communities differing in climate and productivity.We built plant trait networks (PTNs) for 118 species within six communities across an aridity gradient, from forest to semi‐desert across the California Floristic Province, based on 34 leaf and wood functional traits, representing hydraulic and photosynthetic function, structure, economics and size. We developed hypotheses for the association of PTN parameters with climate and ecosystem properties, based on theory for the adaptation of species to low resource/stressful environments versus higher resource availability environments with greater potential niche differentiation. Thus, we hypothesized that across community PTNs, trait network connectivity (i.e., the degree that traits are intercorrelated) and network complexity (i.e., the number of trait modules, and the degree of trait integration among modules) would be lower for communities adapted to arid climates and higher for communities adapted to greater water availability, similarly to trends expected for phylogenetic diversity, functional richness and productivity. Further, within given PTNs, we hypothesized that traits would vary strongly in their network connectivity and that the traits most centrally connected within PTNs would be those with the least across‐species variation.Across communities from more arid to wetter climates, PTN architecture varied from less to more interconnected and complex, in association with functional richness, but PTN architecture was independent of phylogenetic diversity and ecosystem productivity. Within the community PTNs, traits with lower species variation were more interconnected.Synthesis. The responsiveness of PTN architecture to climate highlights how a wide range of traits contributes to physiological and ecological strategies with an architecture that varies among plant communities. Communities in more arid environments show a lower degree of phenotypic integration, consistent with lesser niche differentiation. Our study extends the usefulness of PTNs as an approach to quantify tradeoffs among multiple traits, providing connectivity and complexity parameters as tools that clarify plant environmental adaptation and patterns of trait associations that would influence species distributions, community assembly, and ecosystem resilience in response to climate change.
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Plant functional trait uncertainty can outweigh climate scenario uncertainty in tundra ecosystem productivity
Summary Predicting shifts in species composition with global change remains challenging, but plant functional traits provide a key link to scale from plant to community and ecosystem levels. The extent to which functional trait shifts may mediate ecosystem response to climate change remains a critical question.We ran point‐scale Community Land Model (CLM) simulations with site‐specific functional trait and phenology observations to represent alpine tundra growth strategies. We validated our results with site observations and compared parameterized results to those using the default parameterization. We then quantified the relative contribution of plant functional trait shifts vs climate change scenarios (and the resulting phenological shifts) to uncertainty in future tundra ecosystem productivity outcomes.We found that using community‐specific functional traits and phenology observations significantly improved productivity estimates compared with overestimates in a default simulation. Uncertainty in potential plant trait shifts often had a larger effect on ecosystem productivity responses than uncertainty in the forced response from different climate change scenarios.These findings highlight the key role of functional traits in shaping vegetation responses to climate change and the value of incorporating site‐level measurements into land models to more accurately forecast climate change impacts on ecosystem function.
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- PAR ID:
- 10652740
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- New Phytologist
- ISSN:
- 0028-646X
- Format(s):
- Medium: X
- Associated Dataset(s):
- View Associated Dataset(s) >>
- Sponsoring Org:
- National Science Foundation
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Abstract Plant traits are useful proxies of plant strategies and can influence community and ecosystem responses to climate extremes, such as severe drought. Few studies, however, have investigated both the immediate and lagged effects of drought on community‐weighted mean (CWM) plant traits, with even less research on the relative roles of interspecific vs. intraspecific trait variability in such responses.We experimentally reduced growing season precipitation by 66% in two cold‐semi‐arid grassland sites in northern China for four consecutive years to explore the drought resistance of CWM traits as well as their recovery 2 years following the drought. In addition, we isolated the effects of both interspecific and intraspecific trait variability on shifts in CWM traits.At both sites, we observed significant effects of drought on interspecific and intraspecific trait variability which, in some cases, led to significant changes in CWM traits. For example, drought led to reduced CWM plant height and leaf phosphorous content, but increased leaf carbon content at both sites, with responses primarily due to intraspecific trait shifts. Surprisingly, these CWM traits recovered completely 2 years after the extreme drought. Intraspecific trait variability influenced CWM traits via both positive and negative covariation with interspecific trait variability during drought and recovery phases.These findings highlight the important role of interspecific and intraspecific trait variability in driving the response and recovery of CWM traits following extreme, prolonged drought. Read the freePlain Language Summaryfor this article on the Journal blog.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1111/nph.70740
