Plant Economics Spectrum Research Articles

Predicting ecosystem productivity based on plant community traits.

With the rapid accumulation of plant trait data, major opportunities have arisen for the integration of these data into predicting ecosystem primary productivity across a range of spatial extents. Traditionally, traits have been used to explain physiological productivity at cell, organ, or plant scales, but scaling up to the ecosystem scale has remained challenging. Here, we show the need to combine measures of community-level traits and environmental factors to predict ecosystem productivity at landscape or biogeographic scales. We show how theory can extend the production ecology equation to enormous potential for integrating traits into ecological models that estimate productivity-related ecosystem functions across ecological scales and to anticipate the response of terrestrial ecosystems to global change.

Coordination of economics spectra in leaf, stem and root within the genus Artemisia along a large environmental gradient in China

AbstractAimThe plant economics spectrum provides a fundamental framework for understanding functional trait variation along environmental gradients. However, it is unclear whether there is a general whole‐plant economics spectrum across organs at the finer taxonomic scale (e.g. within genera), and if there is, which factors affect the trait coordination of the different organs. Here, we examined whether resource economics spectra of different organs (i.e. leaf, stem and root) can be integrated at the whole‐plant level within a single genus, and how environment, intraspecific variation and taxonomic scale shape the whole‐plant spectrum.LocationChina.Time period2018.Major taxa studiedArtemisia.MethodsWe sampled 1,022 individuals of 62 Artemisia species in central and eastern China to test trait coordination patterns from organ to whole‐plant level. From the resource economics spectrum perspective, 15 traits were chosen to represent the trade‐off between structural and nutrient investments, including organs’ C, N, P and dry matter content, specific leaf area, specific stem length and specific root length.ResultsPairwise trait correlations and the trade‐off patterns along the resource economic axis were consistent at both organ and whole‐plant levels. Environmental gradients did not strongly affect the correlations among leaf, stem and root economics spectra, that is, the intraspecific variation weakened but did not mask this coordination. Taxonomic scale did not affect the degree of trait coordination as the genus‐wide whole‐plant economics spectrum also emerged within each of the three subgenera.Main conclusionsOur results support the hypothesis that the coordination of economics spectra across organs forms a whole‐plant economics spectrum representing a ‘fast–slow’ resource management strategy, which is robust to recent evolution (genotypic variation, even for species within a single genus) and present‐day environmental variation. Further studies should elucidate in which circumstances or phylogenetic branches the coordinated pattern found for Artemisia is representative of other widely distributed genera.

Shifts in Community Vegetative Organs and Their Dissimilar Trade-Off Patterns in a Tropical Coastal Secondary Forest, Hainan Island, Southern China

The ecology of functional features highlights the importance of the leaf economic spectrum (LES) in understanding plant trade-offs between conservative and commercial resource use. However, it is still unclear whether changes in the plant attributes of various vegetative organs can be altered and whether the plant economic spectrum (PES) is categorized by multiple vegetative organs. We investigated a total of 12 functional features of 174 woody tree species, with leaf and stem attributes, on Hainan Island. We used principal component analysis (PCA) to analyze the changes in attributes and connections to understand how the plant trade-offs differ. We detected that stem organic matter (SOM) and stem organic carbon (SOC) contributed most to the first principal component, followed by leaf organic matter (LOM) and leaf organic carbon (LOC). Using Spearman correlation analysis, we determined that leaf total nitrogen (LTN) and specific leaf area (SLA), LTN and leaf total phosphorus (LTP), and finally stem total nitrogen (STN) and stem total phosphorus (STP) were positively significantly correlated. These significant variations in the traits of nutrients are regulated, while the morphological traits of aboveground vegetative organs are diverse. The coexistence of species and community assembly can increase our knowledge on the tropical coastal secondary forests. Furthermore, our outcomes can help us to better understand the restoration of habitats and green infrastructure design, suggesting that selecting different species across multiple trait axes can help ensure functionality at the maximum level.

The fern economics spectrum is unaffected by the environment.

The plant economics spectrum describes the trade-off between plant resource acquisition and storage, and sheds light on plant responses to environmental changes. However, the data used to construct the plant economics spectrum comes mainly from seed plants, thereby neglecting vascular non-seed plant lineages such as the ferns. To address this omission, we evaluated whether a fern economics spectrum exists using leaf and root traits of 23 fern species living under three subtropical forest conditions differing in light intensity and nutrient gradients. The fern leaf and root traits were found to be highly correlated and formed a plant economics spectrum. Specific leaf mass and root tissue density were found to be on one side of the spectrum (conservative strategy), whereas photosynthesis rate, specific root area, and specific root length were on the other side of the spectrum (acquisitive strategy). Ferns had higher photosynthesis and respiration rates, and photosynthetic nitrogen-use efficiency under high light conditions and higher specific root area and lower root tissue density in high nutrient environments. However, environmental changes did not significantly affect their resource acquisition strategies. Thus, the plant economics spectrum can be broadened to include ferns, which expands its phylogenetic and ecological implications and utility.

Floral and reproductive traits are an independent dimension within the plant economic spectrum of temperate central Europe.

Major dimensions of plant ecological strategies have been widely studied bringing forward the concept of 'economic spectra' of plants. Sexual reproductive traits, 'floral traits', have been largely neglected in this context, despite their strong link to fitness. Here, we aimed at integrating floral traits into the dimensionality of plant form and function so far dominated by vegetative traits. We used principal component analyses and constructed trait networks to assess the correlation structure of leaf, belowground, plant size-related, and floral traits. We studied forbs within two independent datasets; one compiled from central European trait databases and one sampled in the Austrian Alps. Floral traits defined the second dimension of trait variability within both datasets, while plant size determined the first dimension. Floral traits were largely independent from the leaf economic spectrum. Flower size, however, positively scaled with plant size and leaf size. Mating system was the most well-connected trait across modules of plant tissue/organ types. The independence of floral traits was consistent also after accounting for phylogenetic relationships between species. Floral traits explained a unique part of the variation in plant form and function and thus, likely play a distinctive ecological role within the whole plant economic spectrum.

Towards an animal economics spectrum for ecosystem research

Abstract The framework of the plant economics spectrum advanced our understanding of plant ecology and proved as a unifying concept across plant taxonomy, growth forms and biomes. Similar approaches for animals mostly focus on linking life‐history and metabolic theories, but not on their application in ecosystem research. To fill this gap, we propose the animal economics spectrum (AES) based on broadly available traits that describe organismal size, biological times and rates. To exemplify the feasibility and general usefulness of constructing the AES, we compiled data on adult and offspring body mass, life span, age at first reproduction, reproductive and metabolic rate of 98 terrestrial taxa from seven selected animal classes and mapped these taxa into an exemplary quantitative trait space. The AES consists of two principal axes related to reproductive strategies and the pace of life; both axes are linked by animal metabolism. The AES thus closely mirrors seminal ideas on fundamental life‐history strategies and more recent discoveries and developments in the fields of life‐history and metabolic theories. Furthermore, we find associations between the positions of animals within the AES and taxonomy, thermoregulation and body plan. The AES shows that key dimensions describing different ecological strategies of animals can be depicted with functional traits that are relatively easily accessible for a broad spectrum of animal taxa. We suggest future steps towards an application of the AES in ecosystem research aiming at the understanding of ecological processes and ecosystem functions. Additionally, we urge for databases that compile comparable functional traits for a large proportion of animals, but also for further groups of organisms with the ultimate goal to map the economics spectrum of life. The framework of the AES will be relevant for understanding ecological processes across animal taxa at species, community and ecosystem levels. We further discuss how it can facilitate predictions on how the functional composition and diversity of animal communities can be affected by global change. Read the free Plain Language Summary for this article on the Journal blog.

Linking soil nutrients and traits to seedling growth: A test of the plant economics spectrum

Investigating the link among plant growth rates, traits and local environmental heterogeneity is necessary for understanding forest dynamics and community assembly. Although recent results showed that aboveground traits are key for determining organism’s performance and main resource-use strategies, it is clear that organism performance is influenced by both above- and below-ground traits. However, we have limited understanding about how belowground strategies change in response to soil fertility and determine plant performance. We hypothesize that belowground traits have significant effects on plant performance and that shifts in soil nutrient variability are associated to shifts belowground traits. We tested these hypotheses by surveying plant communities including 3969 seedlings represented by 49 common species over a 10-year period, measured soil nutrients, including total nitrogen (TN), phosphorus (TP) and potassium (TK), and leaf and root traits to examine the links among soil nutrients, traits and growth. We first examined the coordination of leaf and root traits of community level, then used traits to predict individual and species mean height growth rate (RGRh). Finally, we tested for shifts in traits in response to gradients of soil nutrients. We found that community-level traits tended to be multidimensional. Species with acquisitive leaf traits, e.g., high leaf area ratio (LAR), phosphorus content (LP), specific leaf area (SLA) and low leaf dry matter content (LDMC), exhibited high growth rates. However, root traits were weak predictors of RGRh, all root traits were not significantly correlated to RGRh of species, only root tissue density (RTD), specific root area (SRA) and length (SRL) was significantly correlated with RGRh of individuals. Community-weighted mean traits only significantly changed along the gradients of limiting soil nutrients, especially for TK and TP. Species with high LN, SLA, root nitrogen content, SRA and SRL, and low tissue density associated with high TK and TP. Ultimately, multidimensional trait variations, and weak links between root traits and growth only partly support the plant economics spectrum (correlation among traits along one axis), but emphasizes that, beyond root traits, other resource uptake processes of roots should be linked to plant performances. Our findings provide further insights into the understanding of how ecological strategies regulate plant performances and shape potential responses of plant communities to environmental change.

Genotypic variation of plant biomass under nitrogen deficiency is positively correlated with conservative economic traits in wheat.

Plant functional traits, including leaf and root economic traits, are important for understanding the composition and function of ecosystems. However, plant functional traits of crop species and the relationships between them, and their responses to environmental variations are not fully understood. In the present study, the traits in the leaf and root economics spectrum (LES and RES) and plant biomass were investigated in 14 wheat genotypes grown with sufficient or limited nitrogen (N) supply. We found that N had significant impacts on the LES and RES traits and on the relationships among them. Our results generally supported the hypothesized LES, but did not support the RES or plant economics spectrum concept among wheat plants regardless of N treatment. More importantly, we found that more conservative leaf and root economic traits are beneficial for shoot biomass accumulation in wheat plants grown with limited N supply, and for the improvement in the tolerance of wheat to N stress. The data presented suggest that growth conditions should be accounted for when studying trait-to-trait relationships, and that more conservative resource use strategies could be used as promising targets for wheat breeding programs with limited N input.

Seed production of co-occurring species: Regenerative strategies, plant economic spectrum or architectural constraints?

Although plant clonality is an important reproductive strategy complementing seed reproduction, their interrelationship is seldom studied. We evaluated how plant clonality, together with plant economics spectrum and architectural constraints, affect the generative reproduction characteristics of co-existing grassland species. For this purpose, we collected data on seed number, seed mass and seed yield (seed mass x seed number) per shoot of 56 herbaceous species from temperate grasslands in the White Carpathian Mts. (SE Czech Republic).Clonality had a weaker effect on seed traits than leaf economics and plant architecture. Metamer size showed the strongest relationship to seed number per shoot, while leaf dry matter content and canopy height were the most important factors affecting average seed mass in the studied species. Seed yield was affected by both leaf nitrogen and metamer size but only for plants with long lived shoots (di- and polycyclic). The negative correlation between seed mass and seed number per shoot for our dataset was confirmed.Our study did not support the idea that clonality is the most important factor affecting seed production in grassland species and pointed out complex relationships of coordinated traits in coexisting species.

Root Growth Dynamics and Structure in Seedlings of Four Shade Tolerant Mediterranean Species Grown under Moderate and Low Light

Specific functional traits such as shade tolerance or leaf habits can enhance root growth dynamics and structure of planted seedlings in the understory of planted forests. We assessed how low and moderate light levels (17 and 33% of full sunlight, mimicking after-thinning stocking) affect the root growth dynamics and structure of four late successional trees, three deciduous (Acer monspessulanum L., Quercus pyrenaica Willd and Sorbus torminalis (L.) Crantz) and one evergreen (Quercus ilex L.) species. Rooting depth, dynamics and structure were mainly explained by species functional differences. Roots of deciduous trees elongated faster and deeper and were larger than the roots of the evergreen Q. ilex. Among deciduous trees, S. torminalis had the lowest root growth. Specific leaf area and nutrient concentration were positively related to root growth, highlighting the importance of traits related to the plant economic spectrum, as determinants of species root growth differences. Moderate light level slightly enhanced root growth and decreased the specific leaf area (SLA). Species differences in water potential under drought were positively related to rooting depth, evidencing the importance of its role in overcoming drought stress during seedling establishment. These findings can guide the selection of late successional, shade tolerant tree species for underplanting thinned Mediterranean plantations and provide insights into their ecology.

Huff and puff and blow down: invasive plants traits response to strong winds at the Southern Oceanic Islands

Invasions constitute a major driver of biodiversity changes. Insular plant communities are particularly vulnerable to invasions and are relevant models for investigating mechanisms supporting the establishment and spread of introduced plants. Terrestrial flora of sub‐Antarctic islands must often thrive in highly windy habitats, thus imposing strong mechanical constraints on individuals. Many alien plants at the sub‐Antarctic islands are of tropical or temperate origins, where they were exposed to less stringent wind conditions. As wind likely represents a strong environmental filter for the successful establishment and further geographic spread of plants, they should have developed responses to resist and successfully colonize the Iles Kerguelen. We studied responses to wind of three herbaceous species that are invasive at Iles Kerguelen. We sampled plant individuals at different locations, under windy and sheltered conditions. Traits related to wind avoidance and tolerance and to resource acquisition were measured. We additionally assessed individual performance (biomass) to determine the consequences of trait variations. We focused on trait mean and variance, in particular, through the calculation of hypervolumes. This study emphasized that wind has important effects on plant economics spectrum, including traits involved in mechanical avoidance and light acquisition, with varying strategies, which seem to depend on the biological type of the species (grass versus non‐grass). Wind generally reduces individual performance, and this negative effect is not direct but operates through the modification of plant trait values. Furthermore, analyses performed at the hypervolume scale indicate that not only functional trait mean but also its variability account for plant performance. The existence of contrasting growth strategies to cope with local environmental conditions suggests that invaders will be able to occupy different niches, which may ultimately impact local communities. Our results highlight the importance of considering multi‐traits responses to meaningfully capture plant adjustments to stress.

Influences of the bark economics spectrum and positive termite feedback on bark and xylem decomposition.

The plant economics spectrum integrates trade-offs and covariation in resource economic traits of different plant organs and their consequences for pivotal ecosystem processes, such as decomposition. However, in this concept stems are often considered as one unit ignoring the important functional differences between wood (xylem) and bark. These differences may not only affect the performance of woody plants during their lifetime, but may also have important "afterlife effects." Specifically, bark quality may strongly affect deadwood decomposition of different woody species. We hypothesized that (1) bark quality strongly influences bark decomposability to microbial decomposers, and possibly amplifies the interspecific variation in decomposition by invertebrate consumption, especially termites; and (2) bark decomposition has secondary effects on xylem mass loss by providing access to decomposers including invertebrates such as termites. We tested these hypotheses across 34 subtropical woody species representing five common plant functional types, by conducting an insitu deadwood decomposition experiment over 12-month in two sites in subtropical evergreen broad-leaved forest in China. We employed visual examination and surface density measurement to quantify termite consumption to both bark and the underlying xylem, respectively. Using principal component analysis, we synthesized seven bark traits to provide the first empirical evidence for a bark economics spectrum (BES), with high BES values (i.e., bark thickness, nitrogen, phosphorus, and cellulose contents) indicating a resource acquisitive strategy and low BES values (i.e., carbon, lignin, and dry matter contents) indicating a resource conservative strategy. The BES affected interspecific variation in bark mass loss and this relationship was strongly amplified by termites. The BES also explained nearly half of the interspecific variation in termite consumption to xylem, making it an important contributor to deadwood decomposition overall. Moreover, the above across-species relationships manifested also within plant functional types, highlighting the value of using continuous variation in bark traits rather than categorical plant functional types in carbon cycle modeling. Our findings demonstrate the potent role of the BES in influencing deadwood decomposition including positive invertebrate feedback thereon in warm-climate forests, with implications for the role of bark quality in carbon cycling in other woody biomes.

Beyond leaf habit: generalities in plant function across 97 tropical dry forest tree species.

Leaf habit has been hypothesized to define a linkage between the slow-fast plant economic spectrum and the drought resistance-avoidance trade-off in tropical forests ('slow-safe vs fast-risky'). However, variation in hydraulic traits as a function of leaf habit has rarely been explored for a large number of species. We sampled leaf and branch functional traits of 97 tropical dry forest tree species from four sites to investigate whether patterns of trait variation varied consistently in relation to leaf habit along the 'slow-safe vs fast-risky' trade-off. Leaf habit explained from 0% to 43.69% of individual trait variation. We found that evergreen and semi-deciduous species differed in their location along the multivariate trait ordination when compared to deciduous species. While deciduous species showed consistent trait values, evergreen species trait values varied as a function of the site. Last, trait values varied in relation to the proportion of deciduous species in the plant community. We found that leaf habit describes the strategies that define drought avoidance and plant economics in tropical trees. However, leaf habit alone does not explain patterns of trait variation, which suggests quantifying site-specific or species-specific uncertainty in trait variation as the way forward.

Differing Trade-Off Patterns of Tree Vegetative Organs in a Tropical Cloud Forest.

Functional trait ecology demonstrates the significance of the leaf economics spectrum in understanding plants’ trade-off between acquisitive and conservative resource utilization. However, whether trait variations of different vegetative organs are coordinated and whether the plant economics spectrum is characterized by more than one vegetative organ remain controversial. To gain insights into these questions, within a tropical cloud forest in Hainan Island, a total of 13 functional traits of 84 tree species were analyzed here, including leaf, stem and root traits. By using standardized major axis (SMA) regression and principal components analysis, we examined the trait variations and correlations for deciphering plants’ trade-off pattern. We found decreases of leaf phosphorus content, leaf nitrogen content and specific leaf area and increases of leaf mass per unit area (LMA), wood density and leaf thickness along the first principal component, while there were decreases of specific root length and specific root area and increases of root tissue density along the second principal component. Root phosphorus and nitrogen contents were significantly positively associated with the phosphorus and nitrogen contents of both stem and leaf. Wood density was significantly positively associated with LMA and leaf thickness, but negatively associated with leaf thickness and specific leaf area. Our results indicate that, in the tropical cloud forest, there is a “fast–slow” economic spectrum characterized by leaf and stem. Changes of nutrient trait are coordinated, whereas the relationships of morphological traits varied independently between plant above- and below-ground parts, while root nutrient traits are decoupled from root morphological traits. Our findings can provide an insight into the species coexistence and community assembly in high-altitude tropical forests.

Putting non-structural compounds on the map of plant life history strategies: a commentary on Schoonmaker et al.

The seminal works of J. Philip Grime established that long-lived plants, like trees, have evolved a continuum of life strategies, spanning from competitors to stress tolerators, that optimize the capture and use of resources under habitats ranging from high to low productivity, respectively (Grime 1977, 2006). Competitors succeed in productive habitats by quickly capturing resources and colonizing space; resources are invested in new biomass to foster further capture. Conversely, the stress- tolerant strategy succeeds in unproductive habitats through a slow and costly-to-construct biomass, which does not require high rates of resource inputs but at the same time is highly resistant against potential losses of the invested resources (e.g., herbivory). These two strategies are comparable to the two end points of the leaf- or plant-economic spectrum, spanning from slow-growing–resource conservative to fast-growing–resource acquisitive (Reich et al. 1997, Westoby et al. 2002, Diaz et al. 2004...

Resolving whole‐plant economics from leaf, stem and root traits of 1467 Amazonian tree species

It remains unclear how evolutionary and ecological processes have shaped the wide variety of plant life strategies, especially in highly diverse ecosystems like tropical forests. Some evidence suggests that species have diversified across a gradient of ecological strategies, with different plant tissues converging to optimize resource use across environmental gradients. Alternative hypotheses propose that species have diversified following independent selection on different tissues, resulting in a decoupling of trait syndromes across organs. To shed light on the subject, we assembled an unprecedented dataset combining 19 leaf, stem and root traits for 1467 tropical tree species inventoried across 71 0.1‐ha plots spanning broad environmental gradients in French Guiana. Nearly 50% of the overall functional heterogeneity was expressed along four orthogonal dimensions, after accounting for phylogenetic dependences among species. The first dimension related to fine root functioning, while the second and third dimensions depicted two decoupled leaf economics spectra, and the fourth dimension encompassed a wood economics spectrum. Traits involved in orthogonal functional strategies, five leaf traits in particular but also trunk bark thickness, were consistently associated with a same gradient of soil texture and nutrient availability. Root traits did not show any significant association with edaphic variation, possibly because of the prevailing influence of other factors (mycorrhizal symbiosis, phylogenetic constraints). Our study emphasises the existence of multiple functional dimensions that allow tropical tree species to optimize their performance in a given environment, bringing new insights into the debate around the presence of a whole plant economic spectrum in tropical forest tree communities. It also emphasizes the key role that soil heterogeneity plays in shaping tree species assembly. The extent to which different organs are decoupled and respond to environmental gradients may also help to improve our predictions of species distribution changes in responses to habitat modification and environmental changes.

Stress-resistance traits disrupt the plant economics - decomposition relationship across environmental gradients in salt marshes

Understanding how plants respond to environmental gradients and influence ecosystem functions remains a core challenge in ecology. Across species and ecosystems, plants have been shown to coordinate leaf, stem, and root traits along a gradient with optimal resource acquisition or conservation strategies at its extremes, termed the plant economic spectrum (PES), in turn driving ecosystem functioning. PES theory has been successfully applied in coastal wetlands to disentangle how the strong abiotic gradients affect ecosystem functions, such as litter decomposition. Yet, wetlands can be dominated by monospecific stands, and it remains unclear whether the PES applies within species. Here, focusing on a globally widespread salt marsh plant, Spartina anglica, we investigated: a) if the PES holds at the intraspecific level along critical abiotic stress gradients (redox potential and soil salinity); b) how intraspecific changes in plant traits along the PES affect litter decomposition; and c) whether these changes in plant strategies influence the abundance of key macro-detritivores, mediating litter decomposition. We found remarkable variation in S. anglica leaf and stem traits, coordinating along the PES and adopting a conservative strategy under stronger abiotic stress. Unexpectedly, leaves with a conservative strategy (higher leaf dry matter content and C/N ratio) attracted more macro-detritivores and decomposed faster. Other facets of litter quality beyond C/N seem to drive these counter-intuitive effects: leaves with a conservative strategy were likely more palatable because of higher protein content and lower toughness (low total carbohydrate content). Our study highlights that intraspecific trait variability can strongly drive litter decomposition, potentially impacting on the carbon storage capacity of salt marshes; and that specific stress-resistance traits can disrupt the PES - ecosystem function relationship.

Digging into the roots: understanding direct and indirect drivers of ecosystem service trade-offs in coastal grasslands via plant functional traits

Recent empirical and theoretical approaches have called for an understanding of the processes underpinning ecosystem service provision. Environmental gradients have shown effects on key plant functional traits that subsequently explain ecosystem properties of several systems. However, little is known concerning how associations between plant functional traits, including both below- and aboveground plant components, predict ecosystem properties and independently measured final ecosystem services. Here, we modeled (1) the responses of the leaf and plant economics spectrum, Plant size axis, and root growth to environmental gradients and (2) how associations between plant functional traits explain trade-offs and synergies between multiple ecosystem properties and final services. Forty-four plots were studied in a coastal marsh landscape of the German North Sea Coast. We used a partial least square structural equation model approach to test the hypothesized model. We found (1) a negative covariation between plant traits pertaining to a size axis and traits explaining both plant growth (roots and stems) and the leaf economics spectrum; (2) this trade-off responded significantly to the land use gradient and nutrient availability, which were both strongly driven by the groundwater gradient; (3) this trade-off explained an initial major trade-off between carbon stocks, at one extreme of the axis, and both the habitat value to conserve endangered plants and forage production for meat and dairy products at the other extreme. However, a secondary trade-off between nature conservation value and forage production, explained by a trade-off between leaf economics spectrum and plant growth in response to the land use intensity gradient, was also found.

Rethinking the Plant Economics Spectrum for Annuals: A Multi-Species Study.

The plant economics spectrum hypothesizes a correlation among resource-use related traits along one single axis, which determines species’ growth rates and their ecological filtering along resource gradients. This concept has been mostly investigated and shown in perennial species, but has rarely been tested in annual species. Annuals evade unfavorable seasons as seeds and thus may underlie different constraints, with consequences for interspecific trait-trait, trait-growth, and trait-environment relations. To test the hypotheses of the plant economics spectrum in annual species, we measured twelve resource-use related leaf and root traits in 30 winter annuals from Israel under controlled conditions. Traits and their coordinations were related to species’ growth rates (for 19 species) and their distribution along a steep rainfall gradient. Contrary to the hypotheses of the plant economics spectrum, in the investigated annuals traits were correlated along two independent axes, one of structural traits and one of carbon gain traits. Consequently, species’ growth rates were related to carbon gain traits, but independent from structural traits. Species’ distribution along the rainfall gradient was unexpectedly neither associated with species’ scores along the axes of carbon gain or structural traits nor with growth rate. Nevertheless, root traits were related with species’ distribution, indicating that they are relevant for species’ filtering along rainfall gradients in winter annuals. Overall, our results showed that the functional constraints hypothesized by the plant economics spectrum do not apply to winter annuals, leading to unexpected trait-growth and trait-rainfall relations. Our study thus cautions to generalize trait-based concepts and findings between life-history strategies. To predict responses to global change, trait-based concepts should be explicitly tested for different species groups.

To grow or survive: Which are the strategies of a perennial grass to face severe seasonal stress?

Abstract More severe seasonal stresses resulting from climate change affect the survival of perennial plant species. The growth–survival trade‐off exemplified in dormant species is a key issue to understand adaptation. As the validity of this trade‐off has yet to be tested in non‐dormant species, it was assessed by exploring the intraspecific variability of strategies to face drought and frost within perennial ryegrass. Three common gardens compared 385 European perennial ryegrass populations along a latitudinal environmental gradient over 3‐years. Persistence, productivity and physiological traits were recorded under contrasting seasonal environments. Decoupling plant responses, that is, growth under favourable summers/winters and plant survival under harsh summers/winters, showed a general trade‐off between growth potential and dehydration survival. Three groups of perennial ryegrass populations were identified according to their contrasting strategies: (a) year‐round productive but stress sensitive populations from wet areas; (b) drought‐tolerant populations with low summer growth potential from drought‐prone areas and (c) frost‐tolerant populations with low winter growth potential from frost‐prone areas. Overall, the populations surviving drought best were more resource conservative, whereas populations of the other groups were more resource acquisitive. However, such overall functional patterns were less meaningful than seasonal variations of resource acquisition potentials. The predicted potential biogeographical distribution of these groups suggests shifts of areas of suitability under climate change over the next decades in Europe. Dehydration escape and dehydration tolerance through reduction of growth potential in summer may become the strategies best adapted to an increasingly large area of Europe. The large intraspecific variability of phenological adaptations within perennial ryegrass reveals that the seasonal modulation of growth potential is crucial to plant adaptation under severe chronic abiotic stresses. The global plant economics spectrum cannot account for contrasting seasonal trade‐offs, which points out the importance of integrating phenological traits as key components of plant strategies. The identification of the trade‐off between growth potential and frost or drought stress survival in this non‐dormant species provides key knowledge to understand the future regional distribution of this major species for grassland ecosystem services. A free Plain Language Summary can be found within the Supporting Information of this article.