RESUMEN

This study investigated the dynamics of reciprocal phenotypic plasticity entailing inducible defense and offense in freshwater ciliate communities in response to altered resource supply and the extent of intraspecific trait variation. Communities consisted of Euplotes octocarinatus (intraguild prey) capable of inducible defense to escape predation, Stylonychia mytilus (intraguild predator) capable of inducible offense to expand its prey spectrum, and Cryptomonas sp. (algal resource). The extent of inducible defense was tested in ten different Euplotes strains in response to freeze-killed Stylonychia concentrate, revealing significant differences in their width and length development. In a subsequent 30-day experiment, four strains were incubated in monoculture and mixture with Stylonychia under continuous and pulsed microalgae supply. The polyclonal Euplotes population outperformed the monoclonal populations, except one, which developed the most pronounced inducible defense and retained the highest biovolume. Stylonychia fluctuated in size, but dominated all communities irrespective of clonal composition. Pulsed resource supply promoted biovolume production of both species. However, periods of resource depletion resulted in more Stylonychia resting cysts, allowing Euplotes to resume growth. Our study provides new insights into interactions of induced defense and intraguild predation under variable environmental conditions, emphasizing the relevance of intraspecific trait variation for predator-prey interactions and community dynamics.

Asunto(s)

RESUMEN

A secondary contact zone (SCZ) is an area where incipient species or divergent populations may meet, mate, and hybridize. Due to the diverse patterns of interspecific hybridization, SCZs function as field labs for illuminating the on-going evolutionary processes of speciation and the establishment of reproductive isolation. Interspecific hybridization is widely present in avian populations, making them an ideal system for SCZ studies. This review exhaustively summarizes the variations in unique traits within avian SCZs (vocalization, plumage, beak, and migratory traits) and the various movement patterns of SCZs observed in previous publications. It also highlights several potential future research directions in the genomic era, such as the relationship between phenotypic and genomic differentiation in SCZs, the genomic basis of trait differentiation, SCZs shared by multiple species, and accurate predictive models for forecasting future movements under climate change and human disturbances. This review aims to provide a more comprehensive understanding of speciation processes and offers a theoretical foundation for species conservation.

RESUMEN

AbstractIn many species, a few individuals produce most of the next generation. How much of this reproductive skew is driven by variation among individuals in fixed traits, how much by external factors, and how much by random chance? And what does it take to have truly exceptional lifetime reproductive output (LRO)? In the past, we and others have partitioned the variance of LRO as a proxy for reproductive skew. Here we explain how to partition LRO skewness itself into contributions from fixed trait variation, four forms of "demographic luck" (birth state, fecundity luck, survival trajectory luck, and growth trajectory luck), and two kinds of "environmental luck" (birth environment and environment trajectory). Each of these is further partitioned into contributions at different ages. We also determine what we can infer about individuals with exceptional LRO. We find that reproductive skew is largely driven by random variation in lifespan, and exceptional LRO generally results from exceptional lifespan. Other kinds of luck frequently bring skewness down rather than increasing it. In populations where fecundity varies greatly with environmental conditions, getting a good year at the right time can be an alternate route to exceptional LRO, so that LRO is less predictive of lifespan.

Asunto(s)

RESUMEN

PREMISE: While many studies have measured the aboveground responses of plants to mycorrhizal fungi at a single time point, little is known about how plants respond belowground or across time to mycorrhizal symbiosis. By measuring belowground responses and growth over time in many plant species, we create a more complete picture of how mycorrhizal fungi benefit their hosts. METHODS: We grew 26 prairie plant species with and without mycorrhizal fungi and measured 14 functional traits to assess above- and belowground tissue quality and quantity responses and changes in resource allocation. We used function-valued trait (FVT) modeling to characterize changes in species growth rate when colonized. RESULTS: While aboveground biomass responses were positive, the response of traits belowground were much more variable. Changes in aboveground biomass accounted for 60.8% of the variation in mycorrhizal responses, supporting the use of aboveground biomass response as the primary response trait. Responses belowground were not associated with aboveground responses and accounted for 18.3% of the variation. Growth responses over time were highly variable across species. Interestingly, none of the measured responses were phylogenetically conserved. CONCLUSIONS: Mycorrhizal fungi increase plant growth in most scenarios, but the effects of these fungi belowground and across time are more complicated. This study highlights how differences in plant allocation priorities might affect how they utilize the benefits from mycorrhizal fungi. Identifying and characterizing these differences is a key step to understanding the effects of mycorrhizal mutualisms on whole plant physiology.

Asunto(s)

RESUMEN

Urban environments are warmer than the rural surroundings, impacting plant phenotypic traits. When plants are present over areas with contrasted conditions such as along urbanization gradients, their phenotypes may differ, and these differences depend on different processes, including phenotypic plasticity, maternal environmental effects and genetic differentiation (local adaptation and/or genetic drift). Successful establishment of alien species along environmental gradients has been linked to high phenotypic plasticity and rapid evolutionary responses, which are easier to track for species with a known residence time. The mechanisms explaining trait variation in plants in urban versus rural microclimatic conditions have received little attention. Using the alien Veronica persica as model species, we measured leaf traits in urban and rural populations and performed a reciprocal common-garden experiment to study how germination, leaf, growth, and flowering traits varied in response to experimental microclimate (rural or urban) and population origin environment (rural or urban). Veronica persica displayed phenotypic plasticity in all measured traits, with reduced germination, development, and flowering under urban microclimate which suggests more stressful growing conditions in the urban than in the rural microclimate. No significant effect of the rural or urban origin environment was detected, providing no evidence for local adaptation to urban or rural environments. Additionally, we found limited signs of maternal environmental effects. We noted the importance of the mother plant and the population identities suggesting genetically based differences. Our results indicate that urban environments are more hostile than rural ones, and that V. persica does not show any adaptation to urban environments despite genetic differences between populations.

Asunto(s)

RESUMEN

Organisms respond to their environment in various ways, including moving, adapting, acclimatising or a combination of responses. Within estuarine habitats, organisms are exposed to naturally variable environmental conditions. In urbanised estuaries, these natural variations can interact with human stressors such as habitat modification and pollution. Here, we investigated trait variation in the golden kelp Ecklonia radiata across an urban estuary - Sydney Harbour, Australia. We found that kelp morphology differed significantly between the more human-modified inner and the less modified outer harbour. Kelp individuals were smaller, had fewer laminae, and lacked spines in the inner harbour where it was warmer, more contaminated and less light was available. Inner harbour populations were characterised by lower tissue nitrogen and higher lead concentrations. These findings provide insights into how environmental variation could affect kelp morphology and physiology, and the high trait variation suggests adaptive capacity in E. radiata.

Asunto(s)

RESUMEN

Plant species respond to varying plant species diversity and associated changes in their abiotic and biotic environment with changes in their phenotype. However, it is not clear to what degree this phenotypic differentiation is due to genotype diversity within populations or phenotypic plasticity of plant individuals. We studied individuals of 16 populations of the clonal herb Taraxacum officinale grown in plant communities of different species richness in a 17-year-old grassland biodiversity experiment (Jena Experiment). We collected 12 individuals in each population to measure phenotypic traits and identify distinct genotypes using microsatellite DNA markers. Plant species richness did not influence population-level genotype and trait diversity. However, it affected the expression of several phenotypic traits, e.g. leaf and inflorescence number, maximum leaf length and seed mass, which increased with increasing plant species richness. Moreover, population-level trait diversity correlated positively with genotype richness for leaf dry matter content (LDMC) and negatively with inflorescence number. For several traits (i.e. seed mass, germination rate, LDMC, specific leaf area (SLA)), a larger portion of variance was explained by genotype identity, while variance in other traits (i.e. number of inflorescences, leaf nitrogen concentration, leaf number, leaf length) resided within genotypes and thus was mostly due to phenotypic plasticity. Overall, our findings show that plant species richness positively affected the population means of some traits related to whole-plant performance, whose variation was achieved through both phenotypic plasticity and genotype composition of a population.

RESUMEN

Among-individual variation in predator traits is ubiquitous in nature. However, variation among populations in this trait variation has been seldom considered in trophic dynamics. This has left unexplored (a) to what degree does among-individual variation in predator traits regulate prey populations and (b) to what degree do these effects vary spatially. We address these questions by examining how predator among-individual variation in functional traits shapes communities across habitats of varying structural complexity, in field conditions. We manipulated Chinese mantis (Tenodera sinensis) density (six or twelve individuals) and behavioral trait variability (activity level by movement on an open field) in experimental patches of old fields with varying habitat complexity (density of plant material). Then, we quantified their impacts on lower trophic levels, specifically prey (arthropods > 4 mm) and plant biomass. Predator behavioral variability only altered prey biomass in structurally complex plots, and this effect depended on mantis density. In the plots with the highest habitat complexity and mantis density, behaviorally variable groups decreased prey biomass by 40.3%. In complex plots with low mantis densities, low levels of behavioral variability decreased prey biomass by 32.2%. Behavioral variability and low habitat complexity also changed prey community composition, namely by increasing ant biomass by 881%. Our results demonstrate that among-individual trait variation can shape species-rich prey communities. Moreover, these effects depend on both predator density and habitat complexity. Incorporating this important facet of ecological diversity revealed normally unnoticed effects of functional traits on the structure and function of food webs.

Asunto(s)

RESUMEN

Variations in functional traits serve as measures of plants' ability to adapt to environment. Exploring the patterns of functional traits of desert plants along elevational gradients is helpful to understand the responses and adaptation strategies of species to changing environments. However, it is unknown whether the relationship between functional traits and elevation is affected by differences in the species' elevational distributions (elevation preference and species' range). Importantly, most researches have concerned with differences in mean trait values and ignored intraspecific trait variation. Here, we measured functional traits of desert plants along a wide elevational gradient in the Tibetan Plateau and adjacent areas and explored functional trait patterns over elevation in species with different elevational distributions. We decomposed trait variation and further investigated characterizations of intraspecific variation. Ultimately, the main drivers of trait variation were identified using redundancy analysis. We found that species' elevational distributions significantly influenced the relationship of functional traits such as plant height, leaf dry matter content, leaf thickness, leaf nitrogen and carbon content with elevation. Species with a lower elevational preference showed greater trait variation than species with a higher elevational preference, suggesting that species that prefer high elevation are more conservative facing environmental changes. We provide evidence that interspecific trait variation in leaf thickness and leaf carbon content decreased with increasing species' range, indicating that increased variations in resistance traits within species make greater responsiveness to environmental changes, enabling species a wider range. Elevation, temperature and precipitation were the main drivers of trait variation in species with a low elevational preference, while the effect of precipitation on trait variation in species with a high elevational preference was not significant. This study sheds new insights on how plants with different elevational distributions regulate their ecological strategies to cope with changing environments.

Asunto(s)

RESUMEN

Ascertaining the traits important for acclimation and adaptation is a critical first step to predicting the fate of populations and species facing rapid environmental change. One of the primary challenges in trait-based ecology is understanding the patterns and processes underpinning functional trait variation in plants. Studying intraspecific variation of functional traits across latitudinal gradients offers an excellent in situ approach to assess associations with environmental factors, which naturally covary along these spatial scales such as the local climate and soil profiles. Therefore, we examined how climatic and edaphic conditions varied across a ~160-km latitudinal gradient to understand how these conditions were associated with the physiological performance and morphological expression within five spatially distinct populations spanning the latitudinal distribution of a model species (Stylidium hispidum Lindl.). Northern populations had patterns of trait means reflecting water conservation strategies that included reduced gas exchange, rosette size and floral investment compared to the southern populations. Redundancy analysis, together with variance partitioning, showed that climate factors accounted for a significantly greater portion of the weighted variance in plant trait data (22.1%; adjusted R2 = 0.192) than edaphic factors (9.3%; adjusted R2 = 0.08). Disentangling such independent and interactive abiotic drivers of functional trait variation will deliver key insights into the mechanisms underpinning local adaptation and population-level responses to current and future climates.

RESUMEN

BACKGROUND AND AIMS: Elevation is a major factor shaping plant populations on a global scale. At the same time, reproductive traits play a major role in plant fitness. With increasing altitude and increasingly harsh conditions, decreases in pollinator visitation rates, sexual investment, seed set, and heterozygosity (due to increased selfing) are expected. In response, selection and/or phenotypic plasticity could lead to an increase in plants' floral displays to increase their attractiveness to pollinators and compensates for the negative fitness impacts of reduced pollinator activity. A large body of literature tests these hypotheses at the among-species level, but empirical evidence at the population level (i.e., wihin-species), where adaptive change may occur, is still limited to species-specific studies. Unravelling the global patterns of change in the reproductive traits, flower visitation rates and heterozygosity of plant populations across variable environmental conditions, especially climate can help us to understand how species are able to cope with shifting conditions associated with global change, particularly in mountains. Here, we used meta-analytic approaches to assess the reproductive changes of plant populations in response to elevation on a global scale. METHODS: We used a data set with 243 paired populations of plants at 'lower' and 'higher' elevations, spanning an elevation range of 0-4380 m asl and taken from 121 angiosperm species and 115 published studies. We analyzed changes in flower number, size and longevity, pollen production, flower visitation rate, seed set and expected heterozygosity.We then tested whether the observed patterns for each trait were dependent upon plant phylogeny and various ecogeographical factors and species traits. KEY RESULTS: We found no evidence of elevation having a global effect on the reproductive traits of angiosperm populations. This null global pattern was not affected by geograph or phylogenetics. CONCLUSIONS: Our results suggest that changes in reproductive traits, flower visitation rates, and heterozygosity in plant populations across elevations are specific to each species and ecosystem. Hence, macroevolutionary (across species) and macroecological patterns of elevation of plant reproduction reported previously are apparently not simply the outcome of microevolutionary changes (within species). This apparent specificity of response across plant species poses difficulties in predicting the effects of global changes and, specifically, climatic changes, on the fate of plant species, populations, and communities.

RESUMEN

Changes in climate and grazing intensity influence plant-community compositions and their functional structure. Yet, little is known about their possible interactive effects when climate change mainly has consequences during the growing season and grazing occurs off growing season (dormant season grazing). We examined the contribution of trait plasticity to the immediate responses in the functional structure of plant community due to the interplay between these two temporally disjunct drivers. We conducted a field experiment in the northern Mongolian steppe, where climate was manipulated by open-top chambers (OTCs) for two growing seasons, increasing temperature and decreasing soil moisture (i.e., increased aridity), and grazing was excluded for one dormant season between these two growing seasons. We calculated the community-weighted mean (CWM) and the functional diversity (FD) of six leaf traits. Based on a variance partitioning approach, we evaluated how much of the responses in CWM and FD to OTCs and dormant season grazing occur through plasticity. The interactive effect of OTCs and the dormant season grazing were detected only after considering the role of trait plasticity. Overall, OTCs influenced the responses in CWM more than in FD, but the effects of OTCs were much less pronounced where dormant season grazing occurred. Thus, warming (together with decreased soil moisture) and the elimination of dormant season grazing could interact to impact the functional trait structure of plant communities through trait plasticity. Climate change effects should be considered in the context of altered land use, even if temporally disjunct.

Asunto(s)

RESUMEN

BACKGROUND: Over the past decade, theory and observations have suggested intraspecific variation, trait-based differences within species, as a buffer against biodiversity loss from multiple environmental changes. This buffering effect can only occur when different populations of the same species respond differently to environmental change. More specifically, variation of demographic responses fosters buffering of demography, while variation of trait responses fosters buffering of functioning. Understanding how both responses are related is important for predicting biodiversity loss and its consequences. In this study, we aimed to empirically assess whether population-level trait responses to multiple environmental change drivers are related to the demographic response to these drivers. To this end, we measured demographic and trait responses in microcosm experiments with two species of ciliated protists. For three clonal strains of each species, we measured responses to two environmental change drivers (climate change and pollution) and their combination. We also examined if relationships between demographic and trait responses existed across treatments and strains. RESULTS: We found different demographic responses across strains of the same species but hardly any interactive effects between the two environmental change drivers. Also, trait responses (summarized in a survival strategy index) varied among strains within a species, again with no driver interactions. Demographic and trait responses were related across all strains of both species tested in this study: Increasing intrinsic growth and self-limitation were associated with a shift in survival strategy from sit-and-wait towards flee. CONCLUSIONS: Our results support the existence of a link between a population's demographic and trait responses to environmental change drivers in two species of ciliate. Future work could dive deeper into the specifics of phenotypical trait values, and changes therein, related to specific life strategies in different species of ciliate and other zooplankton grazers.

Asunto(s)

RESUMEN

There is strong trait dependence in species-level responses to environmental change and their cascading effects on ecosystem functioning. However, there is little understanding of whether intraspecific trait variation (ITV) can also be an important mechanism mediating environmental effects on ecosystem functioning. This is surprising, given that global change processes such as habitat fragmentation and the creation of forest edges drive strong trait shifts within species. On 20 islands in the Thousand Island Lake, China, we quantified intraspecific leaf trait shifts of a widely distributed shrub species, Vaccinium carlesii, in response to habitat fragmentation. Using a reciprocal transplant decomposition experiment between forest edge and interior on 11 islands with varying areas, we disentangled the relative effects of intraspecific leaf trait variation versus altered environmental conditions on leaf decomposition rates in forest fragments. We found strong intraspecific variation in leaf traits in response to edge effects, with a shift toward recalcitrant leaves with low specific leaf area and high leaf dry matter content from forest interior to the edge. Using structural equation modeling, we showed that such intraspecific leaf trait response to habitat fragmentation had translated into significant plant afterlife effects on leaf decomposition, leading to decreased leaf decomposition rates from the forest interior to the edge. Importantly, the effects of intraspecific leaf trait variation were additive to and stronger than the effects from local environmental changes due to edge effects and habitat loss. Our experiment provides the first quantitative study showing that intraspecific leaf trait response to edge effects is an important driver of the decrease in leaf decomposition rate in fragmented forests. By extending the trait-based response-effect framework toward the individual level, intraspecific variation in leaf economics traits can provide the missing functional link between environmental change and ecological processes. These findings suggest an important area for future research on incorporating ITV to understand and predict changes in ecosystem functioning in the context of global change.

Asunto(s)

RESUMEN

High alpine regions are threatened but understudied ecosystems that harbor diverse endemic species, making them an important biome for testing the role of environmental factors in driving functional trait-mediated community assembly processes. We tested the hypothesis that plant community assembly along a climatic and elevation gradient is influenced by shifts in habitat suitability, which drive plant functional, phylogenetic, and spectral diversity. In a high mountain system (2400-3500 m) Región Metropolitana in the central Chilean Andes (33°S, 70°W). We surveyed vegetation and spectroscopic reflectance (400-2400 nm) to quantify taxonomic, phylogenetic, functional, and spectral diversity at five sites from 2400 to 3500 m elevation. We characterized soil attributes and processes by measuring water content, carbon and nitrogen, and net nitrogen mineralization rates. At high elevation, colder temperatures reduced available soil nitrogen, while at warmer, lower elevations, soil moisture was lower. Metrics of taxonomic, functional, and spectral alpha diversity peaked at mid-elevations, while phylogenetic species richness was highest at low elevation. Leaf nitrogen increased with elevation at the community level and within individual species, consistent with global patterns of increasing leaf nitrogen with colder temperatures. The increase in leaf nitrogen, coupled with shifts in taxonomic and functional diversity associated with turnover in lineages, indicate that the ability to acquire and retain nitrogen in colder temperatures may be important in plant community assembly in this range. Such environmental filters have important implications for forecasting shifts in alpine plant communities under a warming climate.

RESUMEN

Black sigatoka disease (BSD) is the most important foliar threat in banana production, and breeding efforts against it should take advantage of genomic selection (GS), which has become one of the most explored tools to increase genetic gain, save time, and reduce selection costs. To evaluate the potential of GS in banana for BSD, 210 triploid accessions were obtained from the African Banana and Plantain Research Center to constitute a training population. The variability in the population was assessed at the phenotypic level using BSD- and agronomic-related traits and at the molecular level using single-nucleotide polymorphisms (SNPs). The analysis of variance showed a significant difference between accessions for almost all traits measured, although at the genomic group level, there was no significant difference for BSD-related traits. The index of non-spotted leaves among accessions ranged from 0.11 to 0.8. The accessions screening in controlled conditions confirmed the susceptibility of all genomic groups to BSD. The principal components analysis with phenotypic data revealed no clear diversity partition of the population. However, the structure analysis and the hierarchical clustering analysis with SNPs grouped the population into four clusters and two subpopulations, respectively. The field and laboratory screening of the banana GS training population confirmed that all genomic groups are susceptible to BSD but did not reveal any genetic structure, whereas SNP markers exhibited clear genetic structure and provided useful information in the perspective of applying GS.

Asunto(s)

RESUMEN

Increasing studies have shown the importance of intraspecific trait variation (ITV) on ecological processes. However, the patterns and sources of ITV are still unclear, especially in the propagules of coastal vegetation. Here, we measured six hypocotyl traits for 66 genealogies of Kandelia obovata from 26 sites and analyzed how ITV in these traits was distributed across geography and genealogy through variance partitioning. We further constructed mixed models and structural equation models to disentangle the effects of climatic, oceanic, and maternal factors on ITV. Results showed that size-related traits decreased along increasing latitudinal gradients, which was mainly driven by positive regulation of temperature on these traits. By contrast, ITV of shape trait was unstructured along latitudinal gradients and did not show any dependence among environmental variables. These findings indicate that propagule size mainly varied between populations, whereas propagule shape mainly varied between individuals. Our study may provide useful insights into the ITV in propagule from different functional dimensions and on a broad scale, which may facilitate mangrove protection in light of ITV.

RESUMEN

Organisms can adapt to environmental heterogeneity through two mechanisms: (1) expression of population genetic variation or (2) phenotypic plasticity. In this study we investigated whether patterns of variation in both trait means and phenotypic plasticity along elevational and latitudinal clines in a North American endemic plant, Mimulus laciniatus, were consistent with local adaptation. We grew inbred lines of M. laciniatus from across the species' range in two common gardens varying in day length to measure mean and plastic trait expression in several traits previously shown to be involved in adaptation to M. laciniatus's rocky outcrop microhabitat: flowering time, size-related traits, and leaf shape. We examined correlations between the mean phenotype and phenotypic plasticity, and tested for a relationship between trait variation and population elevation and latitude. We did not find a strong correlation between mean and plastic trait expression at the individual genotype level suggesting that they operate under independent genetic controls. We identified multiple traits that show patterns consistent with local adaptation to elevation: critical photoperiod, flowering time, flower size, mean leaf lobing, and leaf lobing plasticity. These trends occur along multiple geographically independent altitudinal clines indicating that selection is a more likely cause of this pattern than gene flow among nearby populations with similar trait values. We also found that population variation in mean leaf lobing is associated with latitude. Our results indicate that both having more highly lobed leaves and greater leaf shape plasticity may be adaptive at high elevation within M. laciniatus. Our data strongly suggest that traits known to be under divergent selection between M. laciniatus and close relative Mimulus guttatus are also under locally varying selection within M. laciniatus.

RESUMEN

Environmental changes associated with urbanisation can exert pressure that facilitates both adaptations and plastic responses in plants. Field surveys or common garden experiments (CGE) alone cannot differentiate between the observed phenotypic traits resulting from plastic responses versus evolutionary adaptations to urban environments. We conducted a field survey of habitat environmental factors and four vegetative traits in 12 Commelina communis populations along an urban-rural gradient in the Osaka-Kobe megacity area. We collected seedlings from six of the 12 populations, transplanted them into a greenhouse, and measured six vegetative traits. We investigated correlations between pairs of measured traits in both the field survey and CGE. Plant height and leaf area increased significantly in increasingly developed land areas (DLA) in the field survey, whereas no such variations were found in the CGE, suggesting that the observed phenotypic variation was due to a plastic response to urban eutrophication. Leaf number and specific leaf area (SLA) significantly decreased with increasing DLA in the CGE, suggesting the adaptation of these traits to urban environments. Positive correlations between plant height and leaf area were only observed in urban populations in both the field survey and CGE, indicating the evolution of this trait correlation in urban environments. It has been suggested that urban environments promote both plastic response and genetic divergence of a set of traits in native plants. Our findings suggest that low leaf number, SLA, and positive plant height-leaf area correlations have evolved. In addition, larger plant size is achieved via phenotypic plasticity in urban environments.

Asunto(s)

RESUMEN

Intraspecific variation in plants is a major ecological mechanism whose local determinants are still poorly understood. In particular, the relationship between this variation and human practices may be key to understanding human-nature relationships. We argue that it is necessary to consider how human practices both influence and depend on the phenotypic variability of species of interest. Arnica montana (arnica) is a good model to study the complex interactions between human actions and plant phenotype, as (i) its ecological niche is shaped by human management actions and (ii) its variability has consequences for harvesters. Using a functional trait approach, we examined feedback loops linking management actions, plant phenotype and harvesting practices. In 27 sites in southeastern France, we measured vegetative and reproductive functional traits of arnica of interest for harvesters, and recorded management actions (grazing; mowing) and ecological variables (including height of surrounding vegetation and tree cover). We examined their effects on plant traits with linear mixed models and used path analysis to test if the effects of human management on traits are mediated by the height of surrounding vegetation. Management actions affected functional traits of arnica. Biomass removal practices (grazing, mowing) were associated with smaller plants producing smaller leaves with reduced specific leaf area. We uncovered the core role of the height of surrounding vegetation in determining this phenotype. Tree cover was associated with reduced flowering. The observed intraspecific variation in response to management actions differentially impacts the two main harvesting practices. Flower-head harvesting depends on reproductive traits that are not impacted by mowing (which is done in winter) but adversely affected by tree cover. In contrast, traits associated with large biomass under tree cover or with high surrounding vegetation are favourable for whole-plant harvesters. Our trait-based approach unveiled clear links between management actions and plant phenotype, with impacts on both vegetative and reproductive traits. These changes induced by management also affect the practices of harvesters. We thus demonstrated a feedback loop between human actions and plant phenotype and provided a novel perspective on human-related causes and consequences of plant intraspecific variability.