Plant Community Diversity Research Articles

Mycorrhizal Symbiosis Increases Plant Phylogenetic Diversity and Regulates Community Assembly in Grasslands.

The intricate mechanisms controlling plant diversity and community composition are cornerstone of ecological understanding. Yet, the role of mycorrhizal symbiosis in influencing community composition has often been underestimated. Here, we use extensive species survey data from 1315 grassland sites in China to elucidate the influence of mycorrhizal symbiosis on plant phylogenetic diversity and community assembly. We show that increasing mycorrhizal symbiotic potential leads to greater phylogenetic dispersion within plant communities. Mycorrhizal species predominantly influence deterministic processes, suggesting a role in niche-based community assembly. Conversely, non-mycorrhizal species exert a stronger influence on stochastic processes, highlighting the importance of random events in shaping community structure. These results underscore the crucial but often hidden role of mycorrhizal symbiosis in driving plant community diversity and assembly. This study provides valuable insights into the mechanisms shaping ecological communities and the way for more informed conservation that acknowledges the complex interplay between symbiosis and community dynamics.

Paralleled grazing and mowing differentially affected plant community diversity and productivity in a semi-arid grassland

BackgroundNumerous previous studies have investigated the effects of grazing or mowing on plant community diversity and productivity in grasslands; however, few have deliberately made sound comparison between the effects of paralleled grazing and mowing in terms of biomass removal on plant community diversity and productivity in semi-arid grasslands. Using a 4-year field manipulative experiment, we investigated how moderate intensity of domestic cattle (Bos taurus) grazing and mowing can affect plant community diversity and productivity in the semi-arid grassland in northeastern China, with the attempt to find a better management practice.ResultsOur results showed that grazing significantly increased plant species richness by 9% but did not change plant biomass, whereas mowing did not alter plant species richness but significantly reduced total plant biomass and root biomass by 18% and 12%, respectively, and significantly altered plant community composition, reflected by 32% increase of grass to forb biomass ratio.ConclusionsCattle grazing exerted a neutral effect on plant biomass and a positive effect on plant species richness, suggesting that cattle grazing is a better management practice compared to the paralleled mowing, but longer-term experiments are needed to explore the lasting influences of grazing vs. mowing on grassland productivity, plant diversity and the sustainability.

Diversity patterns of herbaceous community in environmental gradients of dehesa ecosystems

Dehesa is a unique ecosystem associated with high biodiversity, that integrates trees, livestock, and pasture, making agro-pastoral production compatible with sustainability. However, in the last few decades, a manifold of factors have caused a decline in tree vitality, density, and coverage, leading to long-term changes in species composition and ecosystem structure. This study aims to determine changes in the diversity of the herbaceous plant community in relation to environmental characteristics, the phytosanitary state of the holm oak (Quercus ilex L. subsp. ballota (Desf.) Samp.), and possible interactions with biotic agents, including Phytophthora cinnamomi. For this purpose, the floristic composition and alpha diversity of the understory were assessed in two dehesa stands in Southern Spain. Additionally, the spatial heterogeneity (beta diversity) patterns of herbaceous plants were evaluated in relation to a climatic gradient and subplot orientation at the regional, plot, tree, and subplot scales. Our findings show that microsite features and climate substantially impact the herbaceous plant community in dehesa stands. Annual precipitation is a crucial factor affecting the diversity and biomass of herbaceous plants on a broader, regional scale, consistent with its role as a limiting factor in the Mediterranean climate. However, site-level differences, such as soil clay content and plot slope angle, positively correlate with plant biodiversity, growth, and richness, varying with the Biodiversity Index considered. Moreover, microsites resulting from the combined effects of plot and tree are the main drivers of dissimilarities between samples, as expressed by beta diversity. Contrary to our initial hypothesis, our results reveal no significant association between tree health and herbaceous biodiversity decline.

Impact of Plant Community Diversity on Greenhouse Gas Emissions in Riparian Zones.

Plant community succession can impact greenhouse gas (GHG) emissions from the soil by altering the soil carbon and nitrogen cycles. However, the effects of community landscape diversity on soil GHG emissions have rarely been fully understood. Therefore, this study investigated how plant landscape diversity, structure type, and species composition, affect soil GHG emissions in a riparian zone. Soil GHG emissions were assessed by measuring the air samples collected from four study sites, which have different plant community structure types and species compositions (natural sites with complex plants, landscaped sites with fruit trees and grasses, untended sites with ruderals, and farmland sites), using the static chamber method. Significant differences were observed in soil carbon dioxide (CO2; p < 0.001), nitrous oxide (N2O; p < 0.001), and methane (CH4; p = 0.005) emissions. The untended site with ruderals exhibited the highest CO2 emissions, while N2O emissions increased as plant community diversity decreased. All sites acted as sinks for CH4 emissions, with decreased CH4 uptake efficiency in more diverse plant communities. The Mantel test and variance partitioning analysis revealed soil microbial biomass as an indirect influencer of GHG emissions. This study could help predict soil GHG emissions and their global warming potential under future changes in the island riparian zones.

Consistent generalization of plant-hummingbird networks despite increasing vegetation cover across a tropical urban landscape

Human activities, particularly urbanization, profoundly impact ecosystems often resulting in biotic homogenization. Whether or not urban landscapes can sustain diverse pollinator and plant communities is an important question to be addressed. Here, we investigated the influence of urbanization on plant-hummingbird interaction networks in a large tropical city, Belo Horizonte, Brazil. We recorded 13198 legitimate interactions between seven hummingbirds and 57 plant species across 12 local networks. Urban landscapes exhibited predominantly generalized networks, maintaining this pattern across varying vegetation cover and floral resource abundance. Although some functionally specialized hummingbirds with long bills were recorded performing more specialized interactions, urban environments did not generally support specialized networks. Nevertheless, network specialization did increase with the proportion of native nectar plants, emphasizing their importance for maintaining some specialized interactions. Furthermore, we observed a positive effect of plant richness, but not of flower abundance, on hummingbird abundance, indicating that it is not only the amount of flowers, but the diversity of floral resources that may be a key factor in maintaining hummingbirds. Therefore, promoting a diverse assemblage of native plants in urban green areas is crucial for sustainable pollinator communities. Our study highlights that while a biodiverse urban landscape will require careful urban vegetation planning considering both floral resource diversity and availability, vegetation cover per se may not be sufficient to mitigate the negative impacts of urbanization. Maintaining a diverse vegetation with different life forms, flowering phenology, and especially of native plants across the urban landscape is needed to create welcoming spaces for pollinators.

Nitrogen‐fixing plants increase soil nitrogen and neighbouring‐plant biomass, but decrease community diversity: A meta‐analysis reveals the mediating role of soil texture

Abstract Several recent regional studies have cast doubt on the widespread assumption that nitrogen‐fixing plants (N‐fixers) act as facilitators of neighbouring plant communities. We conducted a meta‐analysis to synthesize the effects of N‐fixers on plant communities and to understand how ecological context moderates these effects. We analysed studies that assessed paired effects of N‐fixers and non‐fixers on soil N, neighbouring‐plant (non‐fixer) biomass and plant community diversity; ecological moderators included climate, soil texture and N‐fixer growth form and invasive status. N‐fixers led to higher soil N and neighbouring‐plant biomass, but lower community diversity compared to non‐fixers. The effect of N‐fixers on neighbouring‐plant biomass was strongly mediated by soil texture; N‐fixer invasive status and growth form were also significant mediators of the facilitative effects of N‐fixers. Synthesis: N‐fixer effects lie on a continuum between facilitation and suppression that is moderated by intrinsic and extrinsic processes, and this analysis provides insight into how these factors moderate the effects of N‐fixers. Overall, N‐fixers facilitate neighbour biomass but suppress diversity, though high variation in these effects can be explained in part by ecological context.

Improving restoration outcomes of boreal Sphagnum-dominated peatlands after peat-extraction: The key role of phosphorus fertilization

Fertilization is a common and effective restoration practice for some ecosystems. However, there are still knowledge gaps about the long-term effectiveness and impact of phosphorus fertilization during the restoration of degraded boreal Sphagnum peatlands using the Moss Layer Transfer Technique. Data gathered from 114 peatland sectors restored 1 to 25 years ago, encompassing around 2900 surveyed plots in Eastern Canada, were analyzed to investigate the influence of fertilization on plant re-establishment (cover, height, and aboveground biomass accumulation) and community composition. Fertilization with a low phosphorus dosage (1.64 g P m−2) of granular phosphate rock (P2O5; NPK 0–13-0) proved to accelerate peatland vegetation recovery by favoring a shift in plant community composition towards a Sphagnum dominance. This shift was encouraged by the fast colonization of Polytrichum strictum after fertilization, a nurse plant that stabilizes the peat substrate and facilitates the subsequent establishment of Sphagnum. Phosphorus fertilization increased by 42 % Sphagnum cover 25-year post-restoration and increased approximately by 15 % aboveground biomass accumulation 20-year post-restoration. Conversely, without fertilization, the success of restoration and long-term vegetation trajectories were uncertain. Phosphorus fertilization led to an increase in plant richness in the first 5 to 10 years after restoration and enhanced spatial heterogeneity in species composition throughout the later stages of restoration (20–25 years), suggesting that fertilization may foster dynamic, diverse plant communities. This study emphasizes fertilization's key role in restoring boreal Sphagnum peatland plant communities, especially in areas prone to episodes of freeze-thaw cycles, strongly advocating for the mandatory inclusion of phosphorus fertilization in the restoration process.

The Relationships between Plant Community Stability and Diversity across Different Grassland Types and Their Association with Environmental Factors in the Habahe Forest Area, Xinjiang

The Relationships between Plant Community Stability and Diversity across Different Grassland Types and Their Association with Environmental Factors in the Habahe Forest Area, Xinjiang

Do linear clearings in boreal peatlands recover? Comparing taxonomic, phylogenetic, and functional plant diversity

Land-use changes and anthropogenic disturbances are major threats to biodiversity, affecting ecosystem function and recovery. In boreal Alberta, Canada, petroleum development has led to extensive landscape fragmentation, notably through linear clearings created for seismic exploration that remove surface vegetation and microtopography. Despite partial recovery on forested seismic lines, peatland recovery is often arrested, impacting wildlife and carbon dynamics. Restoration efforts employ silviculture techniques to create microtopography and foster tree growth, but the efficacy of restoration treatments in restoring peatland plant diversity remains uncertain. We compared taxonomic, phylogenetic, and functional diversity of understory plant communities across treated and untreated seismic lines, alongside reference sites in treed bogs and fens. Treated lines generally had a twofold increase in plant height, leaf dry matter content, and foliar nitrogen and phosphorus contents compared to reference sites. In bogs, treated lines differed from reference conditions driven by increases in herbaceous taxa, while fens displayed disparities mainly in taxonomic and phylogenetic diversity. Differential responses of bogs and fens underline the necessity for tailored management strategies. Changes in plant diversity away from restoration targets have implications for ecosystem recovery, emphasizing the importance of long-term monitoring to evaluate the effectiveness of silviculture techniques in restoring boreal peatland plant communities.

Increasing biochar diversity promotes impacts of plant diversity on remediating cadmium in the soil

Abstract Biochar is a promising material for soil remediation. However, most studies testing roles of biochar in soil remediation have considered the use of single types of biochar, and the role of biochar diversity, as well as its interaction with species diversity of plant communities, has rarely been considered. We hypothesize that biochar diversity can influence impacts of plant diversity on soil remediation. We grew grassland communities consisting of three or six plant species in a Cd-contaminated soil mixed with one, two or four types of biochar, with no grassland community and no biochar addition as the controls. Without plant communities or with communities consisting of three species, total Cd was significantly lower in the soil mixed with four types of biochar than in the soil without biochar or mixed with one or two types of biochar. With communities consisting of six species, total Cd decreased with increasing number of biochar types. Without biochar addition, soil total Cd was not influenced by species richness, but with biochar addition, it was lower in the presence of communities with six species than in the absence of plant communities irrespective of how many types of biochar were added. Also, soil total Cd was lower in the presence of communities with six than with three plant species when two or four types of biochar were added. Our study indicates that increasing biochar diversity can promote the impact of plant diversity on remediating soil contaminated by heavy metals such as cadmium.

Topography and soil variables drive the plant community distribution pattern and species richness in the Arjo-Diga forest in western Ethiopia.

Understanding plant community characteristics, distributions, and environmental relationships is crucial for sustainable forest management. Thus, this study examined the relationships between plant community composition and topographic and soil variables within the Arjo-Diga forest. Vegetation data were collected from 72 nested plots (30 × 30 m2 and 2 × 2 m2) systematically laid along nine transects spaced 300 to 700 m apart. Environmental variables, including soil properties and anthropogenic disturbance, were recorded within each main plot. Agglomerative hierarchical cluster analysis and canonical correspondence analysis (CCA) using R software were employed to identify distinct plant community types and examine their relationships with environmental factors. The Shannon‒Wiener diversity index was calculated to quantify and compare species diversity among the identified community types. The analysis revealed five distinct plant community types: 1: Maesa lanceolata-Ehretia cymosa, 2: Trichilia dregeana-Flacourtia indica, 3: Acacia abyssinica-Millettia ferruginea, 4: Combretum collinum-Croton macrostachyus, and 5: Terminalia macroptera-Piliostigma thonningii. The CCA results highlighted the significant influence (p < 0.05) of altitude, CEC, TN, and disturbance on species distribution and plant community formation. The findings indicate that variation in plant communities is closely associated with altitude, TN, and CEC, as well as with disturbance factors such as human interventions, with elevation being the most influential factor. Based on these findings, it is recommended that conservation plans consider the effects of human interventions to address the challenges in conserving forests in the future. Additionally, further research efforts should focus on mitigating disturbance factors and understanding the environmental variables that affect forests to improve their protection.

No general support for functional diversity enhancing resilience across terrestrial plant communities

AbstractAimUnderstanding the mechanisms promoting resilience in plant communities is crucial in times of increasing disturbance and global environmental change. Here, we present the first meta‐analysis evaluating the relationship between functional diversity and resilience of plant communities. Specifically, we tested whether the resilience of plant communities is positively correlated with interspecific trait variation (following the niche complementarity hypothesis) and the dominance of acquisitive and small‐size species (following the mass ratio hypothesis), and for the context‐dependent effects of ecological and methodological differences across studies.LocationGlobal.Time Period2004–2021.Major Taxa StudiedVascular plants.MethodsWe compiled a dataset of 69 independent sites from 26 studies that have quantified resilience. For each site, we calculated functional diversity indices based on the floristic composition and functional traits of the plant community (obtained from the TRY database) which we correlated with resilience of biomass and floristic composition. After transforming correlation coefficients to Fisher's Z‐scores, we conducted a hierarchical meta‐analysis, using a multilevel random‐effects model that accounted for the non‐independence of multiple effect sizes and the effects of ecological and methodological moderators.ResultsIn general, we found no positive functional diversity–resilience relationships of grand mean effect sizes. In contrast to our expectations, we encountered a negative relationship between resilience and trait variety, especially in woody ecosystems, whereas there was a positive relationship between resilience and the dominance of acquisitive species in herbaceous ecosystems. Finally, the functional diversity–resilience relationships were strongly affected by both ecological (biome and disturbance properties) and methodological (temporal scale, study design and resilience metric) characteristics.Main ConclusionsWe rejected our hypothesis of a general positive functional diversity–resilience relationship. In addition to strong context dependency, we propose that idiosyncratic effects of single resident species present in the communities before the disturbances and biological legacies could play major roles in the resilience of terrestrial plant communities.

Annual temperature, body size, and sexual size dimorphism in the evolution of Pyrgomorphidae.

In many animal species, larger body size is positively correlated with male mating success and female fecundity. However, in the case of insects, in high seasonality environments, natural selection favors a faster maturation that decreases the risk of pre-reproductive death. However, this advantageous adaptation comes at a tradeoff, resulting in a reduction in body size. Maturation time is influenced by environmental factors, such as temperature, season length, and food availability during the rains. The geographic variation in these parameters provides an opportunity to study their impact on the adaptive evolution of body size in Pyrgomorphidae grasshoppers. These grasshoppers exhibit remarkable variation in body size and wing development and can be found in diverse plant communities across Africa, Asia, Australia, and tropical America. In this study, we utilized a phylogenetic approach to examine the evolution of body size, considering climatic factors, and the influence of sexual selection on size differences between males and females. We found a positive correlation between mean annual temperature and sexual size dimorphism (SSD). Remarkably, species exhibiting a strong bias toward larger females were found to be adapted to regions with higher temperatures. In the Pyrgomorphidae family, an intermediate body size was identified as the ancestral trait. Additionally, winged male and female grasshoppers were observed to be larger than their wingless counterparts. Despite the potential conflicting pressures on body size in males and females, these grasshoppers adhere to Rench's Rule, suggesting that sexual selection on males' body size may explain the evolution of SSD.

Tree phytochemical diversity and herbivory are higher in the tropics.

A long-standing but poorly tested hypothesis in plant ecology and evolution is that biotic interactions play a more important role in producing and maintaining species diversity in the tropics than in the temperate zone. A core prediction of this hypothesis is that tropical plants deploy a higher diversity of phytochemicals within and across communities because they experience more herbivore pressure than temperate plants. However, simultaneous comparisons of phytochemical diversity and herbivore pressure in plant communities from the tropical to the temperate zone are lacking. Here we provide clear support for this prediction by examining phytochemical diversity and herbivory in 60 tree communities ranging from species-rich tropical rainforests to species-poor subalpine forests. Using a community metabolomics approach, we show that phytochemical diversity is higher within and among tropical tree communities than within and among subtropical and subalpine communities, and that herbivore pressure and specialization are highest in the tropics. Furthermore, we show that the phytochemical similarity of trees has little phylogenetic signal, indicating rapid divergence between closely related species. In sum, we provide several lines of evidence from entire tree communities showing that biotic interactions probably play an increasingly important role in generating and maintaining tree diversity in the lower latitudes.

Predictions of Aboveground Herbaceous Production from Satellite-Derived APAR Are More Sensitive to Ecosite than Grazing Management Strategy in Shortgrass Steppe

The accurate estimation of aboveground net herbaceous production (ANHP) is crucial in rangeland management and monitoring. Remote and rural rangelands typically lack direct observation infrastructure, making satellite-derived methods essential. When ground data are available, a simple and effective way to estimate ANHP from satellites is to derive the empirical relationship between ANHP and plant-absorbed photosynthetically active radiation (APAR), which can be estimated from the normalized difference vegetation index (NDVI). While there is some evidence that this relationship will differ across rangeland vegetation types, it is unclear whether this relationship will change across grazing management regimes. This study aimed to assess the impact of grazing management on the relationship between ground-observed ANHP and satellite-derived APAR, considering variations in plant communities across ecological sites in the shortgrass steppe of northeastern Colorado. Additionally, we compared satellite-predicted biomass production from the process-based Rangeland Analysis Platform (RAP) model to our empirical APAR-based model. We found that APAR could be used to predict ANHP in the shortgrass steppe, with the relationship being influenced by ecosite characteristics rather than grazing management practices. For each unit of added APAR (MJ m−2 day−1), ANHP increased by 9.39 kg ha−1, and ecosites with taller structured herbaceous vegetation produced, on average, 3.92–5.71 kg ha−1 more ANHP per unit APAR than an ecosite dominated by shorter vegetation. This was likely due to the increased allocation of plant resources aboveground for C3 mid-grasses in taller structured ecosites compared to the C4 short-grasses that dominate the shorter structured ecosites. Moreover, we found that our locally calibrated empirical model generally performed better than the continentally calibrated process-based RAP model, though RAP performed reasonably well for the dominant ecosite. For our empirical models, R2 values varied by ecosite ranging from 0.49 to 0.67, while RAP R2 values ranged from 0.07 to 0.4. Managers in the shortgrass steppe can use satellites to estimate herbaceous production even without detailed information on short-term grazing management practices. The results from our study underscore the importance of understanding plant community composition for enhancing the accuracy of remotely sensed predictions of ANHP.

Alpine wetlands degradation leads to soil nutrient imbalances that affect plant growth and microbial diversity

Alpine wetlands degrade rapidly due to climate change and human activities. Studying degradation effects on flora, soil, and microbes, and their mechanisms, can aid wetland management and global carbon dynamic insights. Here, we conducted transect surveys across various levels of degradation in the Qinghai-Tibet Plateau, ranging from non-degraded to severely degraded alpine wetlands. Severe degradation reduced aboveground biomass by 72.5%. As degradation intensified, the abundance of high-quality forage plants, especially Cyperaceae, gradually declined. Degradation resulted in soil nutrient deficiencies and stoichiometric imbalances, which significantly affected plant growth and soil microbial diversity. These changes ultimately led to a decline in carbon sequestration. The diversity of microbial and plant communities’ response to degradation aligned with the “intermediate interference hypothesis.” The altered bacterial community composition, which favors oligotrophic dominance, and its nonlinear response to soil stoichiometry and pH, could explain the maintenance of diversity and species richness of microbial communities under intermediate disturbance.

The Eastern Ghat of India: A review on plant ecological perspectives

The Eastern Ghats, a discontinuous range of mountains spanning Odisha, Andhra Pradesh, Telangana, Tamil Nadu, and Karnataka has a humid tropical monsoon climate with moderate to high temperatures and heavy rainfall. The Eastern Ghats offer a diverse range of flora and fauna, including endemics. The vegetation is classified into various forest types, including moist deciduous, dry deciduous, dry evergreen, evergreen, semi-evergreen, scrub jungles, and savannah. Eastern Ghat reflects the healthy carrying capacity of the ecosystem. The Eastern Ghats boasts a diverse plant community, with over 3200 flowering plant species, largely due to geographic factors, high seasonality, and elevational variations. The Eastern Ghats, a significant biodiversity granary in India, has been the subject of numerous taxonomic and quantitative surveys. The eastern coast of India's eastern forest (Eastern Ghats) is facing a decline in plant diversity due to overexploitation, habitat destruction, and rampant grazing. This has led to species loss and extinction. The forest cover has also decreased due to anthropogenic pressures. However, there is a lack of significant research on plant species population dynamics, soil surveys, soil chemistry, geomorphology, geobotany, pedology, edaphology, and phytochemistry. To address this, modern science and technology approaches, such as geomorphometry and geobotanical studies using Remote Sensing and GIS techniques, are the need of the hour.

The multiple-mechanisms hypothesis of biodiversity–stability relationships

Long-term research in grassland biodiversity experiments has provided empirical evidence that ecological and evolutionary processes are intertwined in determining both biodiversity–ecosystem functioning (BEF) and biodiversity–stability relationships. Focusing on plant diversity, we hypothesize that multifunctional stability is highest in high-diversity plant communities and that biodiversity–stability relationships increase over time due to a variety of forms of ecological complementarity including the interaction with other biota above and below ground. We introduce the multiple-mechanisms hypothesis of biodiversity–stability relationships suggesting that it is not an individual mechanism that drives long-term biodiversity effects on ecosystem functioning and stability but that several intertwined processes produce increasingly positive ecosystem effects. The following six mechanisms are important. Low-diversity plant communities accumulate more plant antagonists over time (1), and use resources less efficiently and have more open, leaky nutrient cycles (2). Conversely, high-diversity plant communities support a greater diversity and activity of beneficial interaction partners across trophic levels (3); diversify in their traits over time and space, within and across species, to optimize temporal (intra- and interannual) and spatial complementarity (4), create a more stable microclimate (5), and foster higher top-down control of aboveground and belowground herbivores by predators (6). In line with the observation that different species play unique roles in ecosystems that are dynamic and multifaceted, the particular mechanism contributing most to the higher performance and stability of diverse plant communities might differ across ecosystem functions, years, locations, and environmental change scenarios. This indicates “between-context insurance” or “across-context complementarity” of different mechanisms. We introduce examples of experiments that will be conducted to test our hypotheses and which might inspire additional work.

Functional responses of understory plants to natural disturbance-based management in eastern and western Canada.

Natural disturbance-based management (NDBM) is hypothesized to maintain managed forest ecosystem integrity by reducing differences between natural and managed forests. The effectiveness of this approach often entails local comparisons of species composition or diversity for a variety of biota from managed and unmanaged forests. Understory vegetation is regularly the focus of such comparison because of its importance in nutrient cycling, forest regeneration, and for wildlife. However, larger scale comparisons between regions with distinct species assemblages may require a trait-based approach to better understand understory responses to disturbance. We compared the long-term effects of retention harvesting on understory vegetation in two large experimental study sites located in eastern and western regions of the Canadian boreal forest. These sites included the Sylviculture en Aménagement Forestier Ecosystémique (SAFE) experiment and the Ecosystem Management Emulating Natural Disturbance (EMEND) experiment, located in the eastern and western regions of Canada, respectively. EMEND and SAFE share common boreal understory species but have distinct tree communities, soils, and climate. Both experiments were designed to evaluate how increasing tree retention after harvest affects biodiversity. Here, we examined taxonomic richness, functional diversity, and functional composition (using community trait mean values) of understory plant communities, and also examine intraspecific trait variability (ITV) for five species common and abundant in both experiments. We observed the limited impacts of retention level on richness, functional diversity, and functional composition of understory plants 20 years postharvest. However, ITV of leaf morphological traits varied between retention levels within each experiment, depending on the species identity. Common species had different functional responses to retention level, showing species-specific reactions to environmental variation. Our result suggests that understory plant communities in the boreal forest achieve resilience to disturbance both in terms of interspecific and intraspecific functional trait diversity. Such diversity may be key to maintaining understory biodiversity in the face of future disturbances and environmental change. Our results reveal the significance of ITV in plant communities for understanding responses to forest harvesting and the importance of choosing appropriate traits when studying species responses to the environment.

Submerged macrophyte self-recovery potential behind restoration treatments: sources of failure.

When exploring the challenges of restoring degraded lakes, we often do not observe the expected results despite executing all planned activities. Our study elucidates the reasons that impede the recovery of submerged macrophytes despite ameliorated light conditions. When prolonged lake degradation occurs, subsequent efforts to increase light availability often prove insufficient, resulting in a persistent turbid water state. In this study, we attempted to determine the reasons for these failures through a germination test and propagule bank analysis conducted in bottom sediments from a severely degraded lake, which underwent restoration. Although the bottom sediments indicate relative potential in the number of oospores and seeds, their germination efficacy remained dismally low. Based on the germination test results and factors affecting the development of submerged macrophytes (physical and chemical parameters, lake morphology), we stated that improvement of light conditions in the lake could be insufficient to recover the vegetation, especially when the potential to renew diverse plant communities from sediments naturally is low. Our findings advocate for a paradigmatic shift in lake restoration strategies. A holistic approach that includes propagule bank assessments before embarking on restoration initiatives and enabling the identification of macrophyte resurgence potentials is recommended. We also advocate for a multifaceted restoration framework, emphasizing the indispensability of augmenting natural recovery mechanisms with targeted interventions. Consequently, in some cases, macrophyte reintroduction could be the only solution. By reintroducing autochthonic species to site-specific ecological dynamics, we anticipate an increased success rate in restituting submerged vegetation, thus catalyzing ecological regeneration within degraded lake ecosystems.