Global trait–environment relationships of plant communities (original) (raw)
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A global meta-analysis of the relative extent of intraspecific trait variation in plant communities
Ecology letters, 2015
Recent studies have shown that accounting for intraspecific trait variation (ITV) may better address major questions in community ecology. However, a general picture of the relative extent of ITV compared to interspecific trait variation in plant communities is still missing. Here, we conducted a meta-analysis of the relative extent of ITV within and among plant communities worldwide, using a data set encompassing 629 communities (plots) and 36 functional traits. Overall, ITV accounted for 25% of the total trait variation within communities and 32% of the total trait variation among communities on average. The relative extent of ITV tended to be greater for whole-plant (e.g. plant height) vs. organ-level traits and for leaf chemical (e.g. leaf N and P concentration) vs. leaf morphological (e.g. leaf area and thickness) traits. The relative amount of ITV decreased with increasing species richness and spatial extent, but did not vary with plant growth form or climate. These results hi...
PLANT FUNCTIONAL TRAITS AND ENVIRONMENTAL VARIATIONS
2013
Since the original Darwin's definition of "functional traits" as predictors (proxies) of organism performance, a growing scientific community, mainly over the last three decades, used the "traitbased" approach to address fundamental ecological and multi-scale questions. The strong link between plant functional traits (PFTs), vegetation processes and ecosystem services, makes this approach particularly promising in the study of vegetation responses to environmental changes (i.e. land use change, climate change, management pressures, etc.). Despite the high amount of papers available, there are many questions still open. In this PhD thesis I describe several applications of the trait-based approach in forest and grassland mountain ecosystems, to explore: (i) the patterns and functional clonal groups and (ii) of community-level PFTs of the herb layer along a coppice forest succession; (iii) the intraspecific variability of PFTs in contrasting grasslands habitats; (iiii) the effects of simulated extreme climatic events on grassland ecosystems. The table below (Tab. 1) summarizes the four approaches.
The plant traits that drive ecosystems: Evidence from three continents
Journal of Vegetation Science, 2004
Question: A set of easily-measured (‘soft’) plant traits has been identified as potentially useful predictors of ecosystem functioning in previous studies. Here we aimed to discover whether the screening techniques remain operational in widely contrasted circumstances, to test for the existence of axes of variation in the particular sets of traits, and to test for their links with ‘harder’ traits of proven importance to ecosystem functioning.Location: central-western Argentina, central England, northern upland Iran, and north-eastern Spain.Recurrent patterns of ecological specialization: Through ordination of a matrix of 640 vascular plant taxa by 12 standardized traits, we detected similar patterns of specialization in the four floras. The first PCA axis was identified as an axis of resource capture, usage and release. PCA axis 2 appeared to be a size-related axis. Individual PCA for each country showed that the same traits remained valuable as predictors of resource capture and utilization in all of them, despite their major differences in climate, biogeography and land-use. The results were not significantly driven by particular taxa: the main traits determining PCA axis 1 were very similar in eudicotyledons and monocotyledons and Asteraceae, Fabaceae and Poaceae.Links between recurrent suites of ‘soft’ traits and ‘hard’ traits: The validity of PCA axis 1 as a key predictor of resource capture and utilization was tested by comparisons between this axis and values of more rigorously established predictors (‘hard’ traits) for the floras of Argentina and England. PCA axis 1 was correlated with variation in relative growth rate, leaf nitrogen content, and litter decomposition rate. It also coincided with palatability to model generalist herbivores. Therefore, location on PCA axis 1 can be linked to major ecosystem processes in those habitats where the plants are dominant.Conclusion: We confirm the existence at the global scale of a major axis of evolutionary specialization, previously recognised in several local floras. This axis reflects a fundamental trade-off between rapid acquisition of resources and conservation of resources within well-protected tissues. These major trends of specialization were maintained across different environmental situations (including differences in the proximate causes of low productivity, i.e. drought or mineral nutrient deficiency). The trends were also consistent across floras and major phylogenetic groups, and were linked with traits directly relevant to ecosystem processes.
Journal of Ecology, 2012
1. Environmental control and dispersal limitation are both essential processes in plant community assembly and species distribution. Although numerous studies in the past decade have examined their importance as determinants of community composition, remarkably little is known about interspecific differences in the importance of these two processes. 2. To quantify these interspecific differences, we compared the importance of environmental factors and space as correlates of species distribution among 24 understorey plant species in a Japanese cool-temperate forest by performing variation partitioning at the species level. Specifically, we hypothesized that the importance of environment and space differs among species, and these differences can be partly predicted from the functional traits and ⁄ or phylogenetic identity of each species. 3. The unique contributions of both environment and space were significant in the community-level analysis. However, at the species level, the relative and absolute sizes of the unique contributions of environment and space differed considerably among the 24 species. Environment and space were not necessarily significant variables explaining the distribution of many species. 4. No significant relationships were found between the unique contribution of environment and the four functional traits tested, that is, dispersal mode, seed mass, plant height and specific leaf area among the 24 species. In contrast, the unique contribution of space was significantly larger in species with no dispersal mechanisms than in animal-dispersed species. No significant phylogenetic signal was detected for the unique contribution of environment or space, suggesting that importance of environmental control and dispersal limitation as determinants of species distribution is evolutionarily labile. 5. Synthesis. Our results suggest that the relative and absolute importance of different processes of community assembly (i.e. environmental control and dispersal limitation) differs remarkably among species even within a single community. These interspecific differences may be explained in part by interspecific differences in dispersal mode.
Climate-trait relationships exhibit strong habitat specificity in plant communities across Europe
Nature Communications, 2023
Ecological theory predicts close relationships between macroclimate and functional traits. Yet, global climatic gradients correlate only weakly with the trait composition of local plant communities, suggesting that important factors have been ignored. Here, we investigate the consistency of climate-trait relationships for plant communities in European habitats. Assuming that local factors are better accounted for in more narrowly defined habitats, we assigned > 300,000 vegetation plots to hierarchically classified habitats and modelled the effects of climate on the community-weighted means of four key functional traits using generalized additive models. We found that the predictive power of climate increased from broadly to narrowly defined habitats for specific leaf area and root length, but not for plant height and seed mass. Although macroclimate generally predicted the distribution of all traits, its effects varied, with habitat-specificity increasing toward more narrowly defined habitats. We conclude that macroclimate is an important determinant of terrestrial plant communities, but future predictions of climatic effects must consider how habitats are defined. Predicting the effects of a changing climate on the diversity and functioning of the ecosphere requires an understanding of how climate drives the distribution of plant species and ecosystem properties 1,2. Ecosystem functioning, such as productivity and nutrient cycling, is strongly determined by the functional composition of the plant community 3-6. Functional traits represent species' life-history strategies 7 , and are often summarized with a few main, largely independent, axes of variation, such as the fast-slow continuum 8 , as reflected in the leaf-economics spectrum 9 , the species' reproductive strategy 10 , the plant size spectrum 7 , and the continuum of collaboration with mycorrhizal fungi 11. A foundational, yet globally weakly supported, assumption in trait-based ecology is that the geographical distribution of dominant functional traits in plant communities is shaped by macroenvironmental gradients, independently of taxonomy 12-14. Here, we addressed this assumption by studying the consistency of macroclimate-trait relationships among European plant communities.
Effects of growing conditions and source habitat on plant traits and functional group definition
2001
Plant functional groups are used to describe patterns of community organization. However, they are defined either by suites of correlated traits or by species groupings, and the responses of these two definitions to changing environmental conditions are unknown. 2. We assessed 14 growth and morphological traits under low-and high-resource conditions of 42 annual plant species from two source communities in Israel that differed in resource availability. As current theory predicts, plants growing in the high-resource treatment were larger, had twofold greater relative growth rate (RGR) and thinner leaves, and allocated less biomass to roots than plants grown in the low-resource treatment. Differences in these traits were less consistent between the two source communities. Instead, taxonomic groups ( grasses, legumes and a group of other forbs), regardless of source, differed in most characteristics. 3. Three general groups of species (functional groups) were identified in both resource treatments using cluster analysis on all 14 traits. In both resource treatments monocots were almost completely separated into one distinct cluster, regardless of source habitat, while the two other, mainly dicot, clusters were partially separated by habitat. However, the species composition and trait characterization of the dicot clusters differed strongly between treatments. Under low-resource conditions the two dicot clusters were separated by size traits and seed mass, but under high-resource conditions, they were separated by above-ground size, morphology and RGR. 4. Principal components analysis demonstrated inconsistency in relationships among traits and species groupings between treatments. The first two principal components emphasized different aspects of growth depending on the treatment; the third axis was defined by growth rates. As with the cluster analysis, plots of species scores revealed relatively little separation of species by habitat. 5. The response of each species varies for different traits and with growing conditions. Variation may differ among species within a functional group, producing different definitions of functional groups under different experimental conditions. Because most functional group analyses are performed on data collected without manipulation of growing conditions, conclusions concerning the response of species or communities to changes in environmental conditions may be problematic. Functional Ecology (2001) 15 , 85-95 1977); 'stress response syndrome' (Chapin 1991); and 'plant ecology strategy scheme' (Westoby 1998) all suggest that suites of morphological and physiological characteristics in plants are correlated with adaptive †To whom correspondence should be addressed. Present address:
Functional Ecology, 2002
1. The concept of plant functional type proposes that species can be grouped according to common responses to the environment and/or common effects on ecosystem processes. However, the knowledge of relationships between traits associated with the response of plants to environmental factors such as resources and disturbances (response traits), and traits that determine effects of plants on ecosystem functions (effect traits), such as biogeochemical cycling or propensity to disturbance, remains rudimentary. 2. We present a framework using concepts and results from community ecology, ecosystem ecology and evolutionary biology to provide this linkage. Ecosystem functioning is the end result of the operation of multiple environmental filters in a hierarchy of scales which, by selecting individuals with appropriate responses, result in assemblages with varying trait composition. Functional linkages and trade-offs among traits, each of which relates to one or several processes, determine whether or not filtering by different factors gives a match, and whether ecosystem effects can be easily deduced from the knowledge of the filters. 3. To illustrate this framework we analyse a set of key environmental factors and ecosystem processes. While traits associated with response to nutrient gradients strongly overlapped with those determining net primary production, little direct overlap was found between response to fire and flammability. 4. We hypothesize that these patterns reflect general trends. Responses to resource availability would be determined by traits that are also involved in biogeochemical cycling, because both these responses and effects are driven by the trade-off between acquisition and conservation. On the other hand, regeneration and demographic traits associated with response to disturbance, which are known to have little connection with adult traits involved in plant ecophysiology, would be of little relevance to ecosystem processes. 5. This framework is likely to be broadly applicable, although caution must be exercised to use trait linkages and trade-offs appropriate to the scale, environmental conditions and evolutionary context. It may direct the selection of plant functional types for vegetation models at a range of scales, and help with the design of experimental studies of relationships between plant diversity and ecosystem properties.
Land-plant ecology on the basis of functional traits
Trends in Ecology & Evolution, 2006
The tissue traits and architectures of plant species are important for land-plant ecology in two ways. First, they control ecosystem processes and define habitat and resources for other taxa; thus, they are a high priority for understanding the ecosystem at a site. Second, knowledge of trait costs and benefits offers the most promising path to understanding how vegetation properties change along physical geography gradients. There exists an informal shortlist of plant traits that are thought to be most informative. Here, we summarize recent research on correlations and tradeoffs surrounding some traits that are prospects for the shortlist. By extending the list and by developing better models for how traits influence species distributions and interactions, a strong foundation of basic ecology can be established, with many practical applications.