Selective logging is the most widespread disturbance in tropical forests, yet how it alters the nutrient balance of regenerating seedlings is poorly resolved, and most stoichiometric studies cannot separate community species turnover from within-species nutrient change. We asked whether multi-element foliar stoichiometry differs among unlogged primary, naturally regenerating, and actively restored forests in Malaysian Borneo, and whether any difference reflects species turnover or within-species adjustment. Six molar ratios (N:P, N:K, N:Ca, N:Mg, Ca:Mg, K:P) were computed for 15 species; because foliar nutrients were measured on samples bulked per species–plot, analyses used 128 deduplicated species–plot profiles. Multivariate stoichiometric composition differed among management types ( p = 0.009 ), but this was largely a by-product of which species were present: species identity explained most ratio variance, and the difference vanished when only species shared between unlogged and logged forests were compared. The wider stoichiometric “niche volume” (the spread of nutrient profiles) of logged forests was likewise turnover-driven. Calcium balance was the exception: Ca:Mg remained management-dependent after controlling for species identity (partial η ^2 = 0.105 ), foliar calcium was consistently lower in logged forests, and within shared species N:Ca rose and Ca:Mg fell after restoration; these calcium patterns were robust to excluding the lianas and the nitrogen-fixing legumes. We conclude that among-management differences in seedling foliar stoichiometry mainly reflect post-logging species turnover, with a composition-robust calcium-balance shift the principal candidate for a genuine biogeochemical change, an important caveat for using foliar stoichiometry in restoration assessment.
Disease-causing plant pathogens are an emerging global threat to forests, compromising carbon sequestration and shifting forests from carbon sinks to sources. Phytophthora agathidicida, the causal agent of a host-specific lethal root rot disease, kauri dieback, infects Agathis australis (New Zealand kauri). The disease causes progressive canopy decline and mortality of kauri, threatening forests where kauri dominate. We hypothesised that increasing kauri dieback severity would reduce growth-driven carbon fluxes while increasing mortality-driven carbon fluxes. Live vegetation carbon stocks were quantified in permanent plots across two censuses, ten years apart. Carbon sequestration was estimated as the difference between carbon growth and losses, which were modelled independently against gradients of kauri dieback severity and initial carbon stocks. We further examined how species-specific proportional contributions to stand carbon varied with total stand carbon and disease severity. Mean carbon stocks across plots were 169.9 ± 17.5 Mg ha⁻¹. Carbon sequestration declined with increasing disease severity due to both reduced productivity and greater carbon loss from mortality, with largest reductions occurring in initially carbon-dense stands. Kauri contributed the largest share of stand carbon, with its dominance increasing in carbon-rich stands owing to the concentration of biomass in large individuals. These findings show that kauri dieback threatens both the carbon sequestration and long-term carbon storage capacity of kauri forests, particularly in mature stands. Conservation efforts that prevent the spread of pathogens and reduce disease symptoms, especially in mature carbon-dense stands, are critical for maintaining the carbon storage capacity of forests.
Understanding root traits is fundamental for interpreting plant survival strategies and selecting optimal seedling ages for ecological restoration. Corethrodendron fruticosum, a common sand-fixing shrub in China’s arid regions, plays a crucial role in ecosystem stability. However, its ontogenetic root trait dynamics remain poorly understood, limiting non-invasive evaluations. To address this, we combined vegetation surveys with whole-plant excavations of 19 individuals, categorized into small, medium, and large individuals using K-means clustering. Biomass, functional traits, and C, N, P stoichiometry were analyzed to characterize lifecycle-dependent strategies. A significant ontogenetic shift toward belowground allocation occurred as plants matured, as evidenced by the root-to-shoot ratio increasing from 0.35 to 2.09. In mature individuals, coarse roots accounted for > 74
Relict populations of Taxus baccata at their southern range limits are increasingly threatened by climate-induced recruitment failure. Understanding the spatial and functional drivers of establishment in these marginal environments is critical for conservation. We analyzed recruitment dynamics in a Mediterranean Fagus sylvatica forest in Northern Greece, utilizing 30 sampling plots to evaluate how distance from nearest adult trees (possible parental) and proximity to streams dictate recruit survival and vigor. Results reveal a distinct ontogenetic shift in spatial recruitment. Seedlings (< 1.3 m height) exhibited a significant non-linear Janzen-Connell distribution, peaking at 2 m from the adult tree trunk (Quadratic GLM, p = 0.017). For the sapling stage (≥ 1.3 m height), this distribution shifted to a strict negative exponential decay (p < 0.001), identifying the adult tree sub-canopy as a vital microclimatic refuge. At the landscape scale, we identified a “quantity vs. quality” trade-off driven by a “hydraulic switch” at a 30-meter distance from the stream. Within the riparian core (≤ 30 m), recruits exhibited vigorous vertical “competitor” architecture (allometric slope β ≈ 0.85). Conversely, in the Upland Zone (> 30 m), recruits adopted a “stunted” stress-tolerator form (β ≈ 0.57) which is likely to mitigate hydraulic failure during severe Mediterranean summer droughts (< 7 mm precipitation). We propose a two-tiered conservation strategy: a 30-meter “Sanctuary Zone” to protect high-vigor phenotypes and a 100-meter buffer managed via Continuous Cover Forestry. Maintaining continuous canopy cover to provide potential nurse-plant facilitation is likely essential to safeguard the microclimatic stability required for the long-term persistence of this relict population.
Delayed self-pollination has long been recognized as a potential strategy for reproductive assurance in flowering plants. This study describes a corolla “twisting” movement that occurs during floral senescence in Iris laevigata, which brings anthers into contact with the stigma. To assess whether this movement functions as a delayed selfing mechanism, pollen viability and stigma receptivity were assessed, and seven treatments with 30 flowers each were applied. The results showed that this species was protandrous with pollen viability declining from 84.6
Climate and elevational gradients influence the spatial variation of tree diversity and community composition across tropical forest ecosystems. The present study examines how water–energy dynamics regulate tree species diversity and community turnover along the elevational gradient of Sri Lanka, a tropical island biodiversity hotspot, using data from 100 National Forest Inventory plots. We tested two hypotheses: that tree diversity declines with elevation in response to interacting reductions in temperature and precipitation, and that community compositional turnover is continuous and gradual rather than punctuated by abrupt transitions along the elevation gradient. Generalized additive models revealed a significant hump-shaped relationship between Shannon diversity and elevation, peaking at approximately 800 m a.s.l., with climate variables jointly explaining 39.7
Riparian forests are key ecological interfaces shaped by strong hydrological disturbance and geomorphological processes, yet their functional structure across broad environmental gradients remains poorly understood. We analyzed the functional structure of riparian vegetation across humid (Yungas) and semiarid (Western Chaco) ecoregions in northwestern Argentina to evaluate patterns of community assembly and propose functional targets for restoration. We sampled woody and herbaceous vegetation in riparian and adjacent forest sectors across ten sites and characterized twelve plant functional traits using a trait-based approach. Functional structure was assessed using multivariate analyses based on community-weighted means. Both ecoregion and habitat sector significantly influenced functional composition, with ecoregion explaining a larger proportion of variation. Contrary to expectations of broad-scale functional convergence, riparian communities exhibited distinct functional trait syndromes associated with regional climatic and geomorphological contexts. However, consistent differentiation between riparian and adjacent habitats was observed across ecoregions, indicating that local environmental filtering operates similarly within each region. Riparian habitats were characterized by deciduous phenology, low wood density, and anemochory dispersal trait, whereas adjacent forests were associated with evergreen phenology and autochory. These results indicate that environmental filtering in riparian systems is scale-dependent and context-specific, reflecting the interaction between fluvial disturbance and regional environmental constraints. The absence of a universal functional template highlights the need for regionally adapted restoration strategies. We propose a functional reference model that integrates hydrogeomorphological and ecological context to guide riparian restoration across contrasting ecoregions.
This study evaluated the reliability of functional data imputed in the classification of ecological strategies according to the CSR model (competitive, stress-tolerant, ruderal) in tree species of a riparian Atlantic Forest in Brazil. Empirical data collected in situ from 68 species were compared with data imputed using the Bayesian Hierarchical Probabilistic Matrix Factorization (BHPMF) technique, considering key functional attributes such as leaf area and specific leaf area. The results showed significant divergences between the classifications based on measured and imputed data, especially for the traits directly involved in the formulation of the CSR model. While imputation overestimated selection for stress tolerance, field data indicated a greater diversity of strategies, with a greater presence of competitive species. The discrepancies point to limitations in the exclusive use of imputed data in local assessments of functional diversity, highlighting the need to integrate empirical collections and improvements in imputation methods for applications in environmental management and restoration.
Understanding the reproductive strategies of rare plant species inhabiting disturbed habitats is essential for predicting their persistence and developing effective conservation measures. Bonamia semidigyna (Convolvulaceae), a rare climber restricted to fragmented roadside habitats in India, remains poorly studied with respect to its reproductive biology. The present study investigated the floral biology, breeding system, and pollination ecology across two natural populations in Tripura, Northeast India, to evaluate factors influencing reproductive success. Pollen viability and stigma receptivity peaked during anthesis, indicating synchronized male and female functionality during the optimal fertilization period. The species exhibited high pollen production but low ovule number, resulting in a high pollen–ovule ratio suggestive of outcrossing. However, controlled breeding experiments demonstrated that B. semidigyna is self-compatible, with high fruit and seed set under both self- and cross-pollination, whereas autonomous self-pollination produced comparatively lower reproductive success. A single butterfly pollinator, Borbo cinnara, was observed visiting the flowers and effectively facilitating pollen transfer. Fruit set increased significantly with increasing single-visit pollen deposition, highlighting the importance of pollinator efficiency in reproductive success. Field observations further suggested the occurrence of pollinator-mediated self-pollination (geitonogamy), particularly under conditions of spatial isolation and asynchronous flowering among individuals. Overall, B. semidigyna exhibits a mixed mating system that combines self-compatibility with pollinator dependence for optimal reproductive output. The study highlights the ecological significance of pollinator activity in maintaining reproductive fitness and suggests that the persistence of this rare species in disturbed habitats may depend strongly on the conservation of its pollination interactions.
Seed dispersal patterns at both species and community levels are widely discussed, but evidence from literature is often limited, especially for natural grasslands. Therefore, we investigated seed dispersal patterns in a natural grassland in Argentina to estimate the reliability of adjacent fields as propagule sources for target species (i.e., native forage species). We installed two different seed trap types (pot and sticky) at distances of 0, 0.1, 2, 4 and 9 m from the vegetation boundaries of an exclosure area, mainly dominated by perennial native grasses. Additionally, we surveyed the aboveground vegetation and estimated the potential seed production for every single species. In total we found 39 plant species in the aboveground vegetation of which 34 were observed to produce seeds and 29 were caught by the seed traps. Over time, species richness, seed density and similarity (Bray-Curtis, Jaccard) to the aboveground vegetation as well as the Shannon diversity index, generally increased. However, these increases were lower at greater distances from the field boundaries, regardless of seed trap type. Overall, pot traps were more effective at catching species and achieved a higher seed density than the sticky traps. Our results highlight the importance of field boundaries as potential sources of seeds for target species and their role in enhancing biodiversity in adjacent grasslands and arable land.
Facilitative interactions are widely recognized for buffering abiotic stress and promoting plant recruitment in drylands, yet their persistence under climate warming remains poorly resolved under field conditions. Here, we experimentally test whether nurse plant facilitation can withstand increasing temperature during the most vulnerable stages of the plant life cycle. We combined open-top chamber warming (0.5–4.5 °C, consistent with CMIP6 projections) with field manipulations of microhabitat (open microsites vs. beneath Neltuma laevigata canopies) to evaluate seedling emergence and early survival of two Chihuahuan Desert cacti (Kroenleinia grusonii and Ferocactus latispinus). Warming altered emergence patterns in a species-specific manner, in some cases enhancing seedling emergence beneath nurse plants following precipitation pulses. However, these transient benefits did not translate into successful recruitment: warming consistently reduced seedling survival across both species and microhabitats, overriding the protective effects of nurse plants. Mortality was rapid and nearly complete in open microsites, and remained high even under canopy cover, indicating only partial buffering. These results suggest that facilitation operates within a constrained thermal window and may become less effective when physiological thresholds are exceeded. Consequently, climate warming is likely to shift recruitment bottlenecks from seedling emergence to post-emergence survival, effectively narrowing the regeneration niche of desert plants. By linking microclimatic buffering with demographic responses across life stages, our study provides empirical evidence for a thermal limit of facilitation and highlights its implications for community assembly and ecosystem resilience under climate change.
Biological invasions provide unique insights into how ecological strategies and population genetic processes contribute to species success. However, decoupling the effects of functional trait divergence from population genetic structure remains challenging, particularly in biodiversity hotspots where invasive and endemic congeners coexist. This study evaluated the concordance between SSR-based population-genetic structure and field-expressed functional trait variation in invasive and endemic species of two distinct genera in the Kashmir Himalaya. We compared two invasive taxa (Ranunculus distans and Artemisia absinthium) with two narrowly endemic congeners (R. palmatifidus and A. amygdalina), combining population genetic analyses based on 12 polymorphic microsatellite loci (six per genus) with individual-level measurements of growth, leaf morphology, and biomass traits across natural populations. Invasive taxa generally maintained higher or more widely distributed genetic variation, but species-specific AMOVA showed that population structuring differed in a genus-specific manner rather than being uniformly lower in invasive congeners. In Artemisia, among-population variation was higher in the endemic A. amygdalina than in the invasive A. absinthium, whereas in Ranunculus, the invasive R. distans showed higher among-population variation than the endemic R. palmatifidus. Functional analyses revealed clear, trait-specific differentiation between invasive and endemic congeners. Invasive taxa generally occupied a more acquisitive region of trait space, particularly through greater leaf area and biomass accumulation, whereas endemic taxa showed more restricted trait distributions. Multivariate analyses indicated that functional differentiation was concordant with SSR-based population structure. Because the functional traits were measured under field conditions and SSR markers represent neutral population-level variation, these results are interpreted as associative rather than as direct evidence of genetic control over trait expression. Overall, the study suggests that demographic connectivity, lineage-specific population structuring and field-expressed functional strategies jointly contribute to the contrasting ecological performance of invasive and endemic congeners in the Himalayan Mountain ecosystems.
Ageratina adenophora is an invasive alien species, that spreads worldwide along subtropical and temperate regions. It has significant negative impacts on natural ecosystems and native flora. However, one of the procumbent native herb Geranium nepalense has been observed frequently with A. adenophora, and their trait variation could be of great significance to understand how they cope with invasion stress. This study aims to analyse trait variation in G. nepalense under A. adenophora canopy. Individual plants of G. nepalense were sampled from highly invaded, moderately invaded and uninvaded sites. The sampled individuals were assessed for ramet densities, lengths of vegetative parts, numbers of flowers and seeds, and their biomasses. The results showed a significant decrease in ramet density but increase in length of vegetative and reproductive parts under both level of invasion. Additionally, numbers of inflorescences were high in both invasion levels compared with uninvaded site; but interestingly, numbers of flowers remained constant. Further, stems and leaves accumulated high biomass under invasion with loss of biomass in seeds. These results conclude that G. nepalense tends to be longer with enlarged vegetative and floral parts under invasion and shifted from procumbent to erect herb. Overall, G. nepalense exhibits adaptive plasticity by strategically reallocating resources and shifting habit under invasion stress. However, decreased seed biomass may have potential negative effects on germination success and early development of progeny. Hence, long-term monitoring is necessary to understand how such responses will influence native plants performance, reproductive success, and persistence of responses to bring some sort of evolutionary changes.
Bilberry (Vaccinium myrtillus) and cowberry (V. vitis-idaea) are foundational species in Northern Europe. Specific leaf area (SLA) is a key trait because it specifies the relative thickness of the leaves, indicating both the plant's response to environmental conditions and its effects on the environment. Identifying factors influencing SLA is therefore essential for understanding how these plants respond to environmental perturbations like climate change and forest management, as well as feedback effects on the plant's environment. Here, we test how the SLA of these two plant species responds to overstory density and tree species composition across an extensive climatic gradient. We focused on two forest types in Sweden: dominated by an overstory of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies); hereon spruce-pine, and an overstory of Norway spruce and birch (Betula sp.); hereon spruce-birch. Our results show that the SLA of both bilberry and cowberry increases (thinner leaves) significantly with higher forest density, whereas it declines with a greater proportion of pine or birch. Increasing soil moisture had a negative effect on SLA of both species in the spruce-birch context, whereas soil fertility never was a significant determinant. Additionally, we observed that the species-specific response in SLA was related to macroclimate and leaf age, with lower SLA in colder climate and older leaves. These findings highlight the importance of considering the effects of forest structure and composition on the SLA in forest management, as shifts in SLA may have implications for ecosystem functioning under present and future climates.
Plant traits show multiple degrees of variation, owing to different environmental conditions or genetic predisposition. Land-use intensification, caused by fertilization, grazing, and mowing changes the biotic and abiotic conditions of a plant’s environment. Land-use can have direct effects on plant traits, such as decreased flower height and size caused by grazing or mowing and enhanced vegetative growth upon fertilisation. Additionally, land-use can shape the plant community that indirectly affects inter or intraspecific competition for nutrition, space, and pollination for a plant individual. In this study, we aimed to elucidate the effects of land-use and associated changes in plant communities on the variation in floral morphology and rewards within and between populations. Floral traits for two common, self-incompatible meadow species – Ranunculus acris and Trifolium pratense, were recorded from semi-natural managed grasslands in Germany. Our study revealed that land-use intensity directly affected flower display size, which correlated with changes in pollen quantity and nectar sugar content. Variation in floral traits, however, varied primarily with changes in the surrounding plant community. Floral morphological traits showed lower intraspecific variation than floral reward traits. In plant-rich communities, both species increased floral display size, but this correlated with reduced pollen and nectar sugar production in R. acris and increased pollen and nectar sugar production in T. pratense, suggesting a species-specific modulation of floral traits that may have implications for plant–pollinator interactions and community-level pollination dynamics.
The complex interplay of ecological gradients, habitat heterogeneity, and species-specific traits usually shape orchid diversity and distribution in Mediterranean ecosystems. In this study, we surveyed terrestrial orchids across 65 diversified sites in northern Morocco’s Intercontinental Biosphere Reserve of the Mediterranean (IBRM). Overall, 26 orchid taxa were recorded across different substrates and environments with calcareous substrates supporting 1,775 individuals compared to 128 on siliceous ones. The Outlying Mean Index analysis revealed clear patterns of ecological specialization across environmental gradients. Five orchid species (Epipactis tremolsii Pau, Limodorum trabutianum Batt., Orchis anthropophora (L.) All., Ophrys battandieri E.G.Camus, and Orchis mascula subsp. laxifloriformis Rivas Goday B.Rodr.) exhibited strong marginality indicating high specialization associated with narrow niches and specific environmental preferences (particularly in cooler, mid- to high-elevation habitats with distinct substrates), while others were moderately specialized or generalists displaying broader tolerance (more common at higher elevations and warmer sites). The main drivers influencing orchid distribution were elevation, moisture, habitat types and substrate type. Hierarchical clustering further distinguished four ecological groups linked to specific habitat types and environmental conditions. Serapias spp. mainly occurred in high-moisture habitats, whereas most Ophrys and Orchis members preferred forested calcareous sites. Our findings underscore the importance of habitat heterogeneity and substrate type in maintaining orchid diversity, thus providing a valuable framework for conservation strategies in Mediterranean North Africa and beyond.
Biological invasions increasingly alter ecosystem structure and function, yet the mechanisms enabling sustained dominance of certain plant invaders remain incompletely integrated across taxa. This review integrates current evidence on five globally impactful species: Parthenium hysterophorus, Chromolaena odorata, Mikania micrantha, Lantana camara, and Ageratum conyzoides to identify shared functional strategies that promote ecological persistence and spread. Drawing from studies on reproductive ecology, allelopathy, soil modification, and disturbance responses, we examine how these species modify plant-soil feedbacks, suppress native regeneration, and restructure nutrient and microbial dynamics in invaded habitats. Despite differences in growth form and biogeographic history, these invaders exhibit convergent traits, including high propagule pressure, flexible germination behavior, vegetative regeneration, allelopathic potential, and broad environmental plasticity. Together, these mechanisms generate a reinforcing invasion pathway characterized by rapid colonization, competitive exclusion, and progressive ecosystem transformation. By synthesizing these cross-species patterns, we move beyond isolated case studies to propose an integrative mechanistic framework explaining sustained invasion success within Asteraceae and Verbenaceae taxa. While the ecological consequences of these invasions include biodiversity loss and altered soil functioning, their substantial biomass production and bioactive compounds also present complex management considerations. Effective control strategies must therefore address seed bank persistence, soil feedback disruption, and post-removal restoration simultaneously. Understanding the interacting ecological processes underlying invasion success is essential for predicting spread dynamics and designing adaptive management interventions under ongoing environmental change.
In harsh high-altitude environments, trees tend to allocate more carbon to storage to ensure survival and growth under adverse conditions. However, the carbon allocation strategies of coexisting evergreen and deciduous conifers in high-altitude environments remain poorly understood. In this study, we investigated Larix principis-rupprechtii and Picea meyeri, two dominant treeline species naturally distributed on the Wutai Mountain, China. We measured the concentrations of soluble sugar, starch, and nonstructural carbohydrates (NSC) in one-year-old needles, one-year-old branches, and stems at different altitudes (approximately 1800–2750 m a.s.l.). Our results revealed that L. principis-rupprechtii showed higher NSC concentrations in both branches and stems compared with P. meyeri, whereas the NSC concentrations in the needles were similar between the two species. The concentrations of NSC and their components in most organs of L. principis-rupprechtii and P. meyeri did not decrease with increasing altitude; instead, they often increased near the treeline. In addition, compared with P. meyeri, which maintained relatively stable NSC concentrations across altitudes, L. principis-rupprechtii showed marked fluctuations among organs along the altitudinal gradient, indicating greater sensitivity to environmental variation. These findings demonstrate that L. principis-rupprechtii maintains higher NSC concentrations than P. meyeri and actively accumulates NSC under harsh environmental conditions, which may represent a physiological strategy enabling L. principis-rupprechtii to survive and persist at higher altitudes.
Global warming is altering seasonal temperature regimes. However, community outcomes tend to be species-specific and can vary greatly, making it difficult to predict vegetation responses. Plasticity in functional traits may be a key mechanism buffering species-level biomass decline under warming conditions, but which trait axes are most consequential and whether buffering operates consistently under seasonally asymmetric warming remain unclear. In this study, we aimed to test this hypothesis by manipulating year-round, summer, and winter warming in a semi-arid grassland in Mongolia. We quantified species-level biomass responses alongside plasticity in leaf height and economic traits (specific leaf area and leaf dry matter content) and assessed concurrent shifts in community-weighted mean (CWM) traits. Warming tended to alter community biomass, species richness, and CWM traits, but only CWM leaf height showed a significant overall treatment effect and pairwise differences among warming treatments, indicating a shift toward lower-stature community structure. Across species, biomass consistently responded to warming negatively, but responses were less negative in species in which leaf height and specific leaf area reduced the most. In contrast, plasticity in leaf dry matter content was not associated with biomass response, and plasticity–biomass relationships did not differ among seasonal warming treatments. Our results demonstrate that species-level plasticity along structural and leaf economic axes can buffer warming-induced biomass declines in a semi-arid grassland. In conclusion, not all plasticity is equally functional, and identifying key trait dimensions improves mechanistic predictions of plant response to climate warming.
Seed dispersal by animals and wind may form pair-growing trees (PGTs) and influence forest community dynamics via competition, but such impacts are hardly assessed, especially at the growth stage. In a temperate forest in Northeast China, we assessed the dependency probability, health, and growth of single-growing trees (SGTs) and PGTs of three dominant conifers: Abies nephrolepis (a highly shade-tolerant species currently dominant in secondary forests, wind-dispersed with potential animal secondary dispersal), Pinus koraiensis (the dominant climax species of primary mixed forests, animal-dispersed), and Picea jezoensis (a shade-tolerant species commonly associated with primary forests, wind-dispersed with animal secondary dispersal). We found that A. nephrolepis in PGTs had a higher proportion of unhealthy individuals than conspecific SGTs; heterospecific PGTs of all three species showed significantly lower relative growth rates than their SGTs (10–18
