| 1. |
- Kattge, Jens, et al.
(författare)
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TRY plant trait database - enhanced coverage and open access
- 2020
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Ingår i: Global Change Biology. - : Wiley-Blackwell. - 1354-1013 .- 1365-2486. ; 26:1, s. 119-188
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Tidskriftsartikel (refereegranskat)abstract
- Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.
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| 2. |
- Flores, Olivier, et al.
(författare)
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An evolutionary perspective on leaf economics : phylogenetics of leaf mass per area in vascular plants
- 2014
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 4:14, s. 2799-2811
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Tidskriftsartikel (refereegranskat)abstract
- In plant leaves, resource use follows a trade-off between rapid resource capture and conservative storage. This worldwide leaf economics spectrum consists of a suite of intercorrelated leaf traits, among which leaf mass per area, LMA, is one of the most fundamental as it indicates the cost of leaf construction and light-interception borne by plants. We conducted a broad-scale analysis of the evolutionary history of LMA across a large dataset of 5401 vascular plant species. The phylogenetic signal in LMA displayed low but significant conservatism, that is, leaf economics tended to be more similar among close relatives than expected by chance alone. Models of trait evolution indicated that LMA evolved under weak stabilizing selection. Moreover, results suggest that different optimal phenotypes evolved among large clades within which extremes tended to be selected against. Conservatism in LMA was strongly related to growth form, as were selection intensity and phenotypic evolutionary rates: woody plants showed higher conservatism in relation to stronger stabilizing selection and lower evolutionary rates compared to herbaceous taxa. The evolutionary history of LMA thus paints different evolutionary trajectories of vascular plant species across clades, revealing the coordination of leaf trait evolution with growth forms in response to varying selection regimes.
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| 3. |
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| 4. |
- Kuppler, Jonas, et al.
(författare)
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Global gradients in intraspecific variation in vegetative and floral traits are partially associated with climate and species richness
- 2020
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 29:6, s. 992-1007
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Tidskriftsartikel (refereegranskat)abstract
- AimIntraspecific trait variation (ITV) within natural plant communities can be large, influencing local ecological processes and dynamics. Here, we shed light on how ITV in vegetative and floral traits responds to large‐scale abiotic and biotic gradients (i.e., climate and species richness). Specifically, we tested whether associations of ITV with temperature, precipitation and species richness were consistent with any of four hypotheses relating to stress tolerance and competition. Furthermore, we estimated the degree of correlation between ITV in vegetative and floral traits and how they vary along the gradients.LocationGlobal.Time period1975–2016.Major taxa studiedHerbaceous and woody plants.MethodsWe compiled a dataset of 18,401 measurements of the absolute extent of ITV (measured as the coefficient of variation) in nine vegetative and seven floral traits from 2,822 herbaceous and woody species at 2,372 locations.ResultsLarge‐scale associations between ITV and climate were trait specific and more prominent for vegetative traits, especially leaf morphology, than for floral traits. The ITV showed pronounced associations with climate, with lower ITV values in colder areas and higher values in drier areas. The associations of ITV with species richness were inconsistent across traits. Species‐specific associations across gradients were often idiosyncratic, and covariation in ITV was weaker between vegetative and floral traits than within the two trait groups.Main conclusionsOur results show that, depending on the traits considered, ITV either increased or decreased with climate stress and species richness, suggesting that both factors can constrain or enhance ITV, which might foster plant‐population persistence in stressful conditions. Given the species‐specific responses and covariation in ITV, associations can be hard to predict for traits and species not yet studied. We conclude that consideration of ITV can improve our understanding of how plants cope with stressful conditions and environmental change across spatial and biological scales.
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| 5. |
- Lehsten, Dörte, et al.
(författare)
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Simulation of Water Level Fluctuations in Kettle Holes Using a Time Series Model
- 2011
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Ingår i: Wetlands. - : Springer Science and Business Media LLC. - 0277-5212 .- 1943-6246. ; 31:3, s. 511-520
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Tidskriftsartikel (refereegranskat)abstract
- Kettle holes are widespread in moraine landscapes. Their hydrological properties may be very vulnerable to changes in climatic conditions. To increase our knowledge of how kettle holes function and how they may be affected by climate change requires a model that can be applied to a variety of them regardless of their properties. We used the PIRFICT time series model to simulate the water levels in kettle holes over the last 50 years. For model calibration we applied time series of two-year lengths. We observed correlations between climate indices and water level statistics with a delayed response of one year. The results show a decrease in autumn low water levels and an increase in water level fluctuations. These effects correspond to observed increased summer evaporation and winter precipitation, and imply that the habitat quality dynamic of kettle holes depends on climatic conditions. With the prognosis of even warmer and dryer summers in Europe in the future, conservation strategies for kettle holes should include the effects of climate change.
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| 6. |
- Lehsten, Veiko, et al.
(författare)
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Fourth-corner generation of plant functional response groups
- 2009
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Ingår i: Environmental and Ecological Statistics. - : Springer Science and Business Media LLC. - 1352-8505 .- 1573-3009. ; 16:4, s. 561-584
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Tidskriftsartikel (refereegranskat)abstract
- Plant functional response groups (PFGs) are now widely established as a tool to investigate plant-environment relationships. Different statistical methods to form PFGs are used in the literature. One way is to derive emergent groups by classifying species based on correlation of biological attributes and subjecting these groups to tests of response to environmental variables. Another way is to search for associations of occurrence data, environmental variables and trait data simultaneously. The fourth-corner method is one way to assess the relationships between single traits and habitat factors. We extended this statistical method to a generally applicable procedure for the generation of plant functional response groups by developing new randomization procedures for presence/absence data of plant communities. Previous PFG groupings used either predefined groups or emergent groups i.e. classifications based on correlations of biological attributes (Lavorel et al Trends Ecol Evol 12:474-478, 1997), of the global species pool and assessed their functional response. However, since not all PFGs might form emergent groups or may be known by experts, we used a permutation procedure to optimise functional grouping. We tested the method using an artificial test data set of virtual plants occurring in different disturbance treatments. Direct trait-treatment relationships as well as more complex associations are incorporated in the test data. Trait combinations responding to environmental variables could be clearly distinguished from non-responding combinations. The results are compared with the method suggested by Pillar (J Veg Sci 10:631-640) for the identification of plant functional groups. After exploring the statistical properties using an artificial data set, the method is applied to experimental data of a greenhouse experiment on the assemblage of plant communities. Four plant functional response groups are formed with regard to differences in soil fertility on the basis of the traits canopy height and spacer length.
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| 7. |
- Lehsten, Veiko, et al.
(författare)
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Turnover of plant trait hierarchies in simulated community assembly in response to fertility and disturbance
- 2007
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Ingår i: Ecological Modelling. - : Elsevier BV. - 0304-3800. ; 203:3-4, s. 270-278
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Tidskriftsartikel (refereegranskat)abstract
- Plant ecologists have placed increasing emphasis on a functional understanding of vegetation. One way to gain insight into the assemblage of vegetation communities is to investigate plant trait responses to environmental gradients or experimental treatments. We present simulations of responses of suites of traits to treatments differing in soil resources and disturbance intensity, in order to construct a functional response hierarchy of traits. We focus on the traits specific leaf area (SLA), plant height, seed mass and life cycle. Though only four traits are varied, these traits are connected to other traits either through trade-offs (e.g. SLA with leaf life span and relative growth rate, seed mass with seed number) or allometric rules (e.g. above-ground biomass scales positively with below-ground biomass). Thus a wide range of plant life history is represented in the simulations. We simulated the assemblage of plant types composed of these traits at two fertility levels and four disturbance treatments, i.e. every 7 years, annually, or monthly mown, and annually ploughed. We present the results of a simulation using LEGOMODEL, an individual-based, spatially explicit, ecological field model and develop a novel method to construct a functional response hierarchy of traits. A competitive ranking of plant types is constructed and subsequently translated into a functional response hierarchy of traits on the basis of the variability of trait states within the plant type ranking. The competitive superior trait states as well as the functional hierarchy change between different treatments. Except for deeply disturbed conditions, perennial plants are always superior. Tall canopy height is superior on fertile soil, as long as it is not mown monthly. High SLA is advantageous at fertile or ploughed sites. Life cycle and canopy height are always at the first two ranks of the functional hierarchy of traits. Our results concerning the advantageous trait states are in line with published field studies, except for the trait seed mass. Here LEGOMODEL predicts competitive advantage of small seeds under any treatment. The functional response hierarchy of traits presents a hypothesis to be refined by further field research as we know of no field study addressing this question. (C) 2006 Elsevier B.V. All rights reserved.
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