Trait-based Approach Research Articles

Trait-based classification and environmental drivers of phytoplankton functional structure from anthropogenically altered tropical creek, Thane Creek India

The present study on variability in phytoplankton functional structure through a trait-based approach described the species-trait-environmental relationship and its possible impact on ecosystem functioning. Based on trait similarities 102 phytoplankton species were clubbed into 14 distinct functional groups. Among others, FGs-XI and XII (small size, chain-forming species with medium to high SA:V ratio and space between cells in chain) were the most dominant due to their competitive advantage in resource utilization and avoidance of loss processes. The morphological traits space between cells and cellular protrusion along with temperature and ammonia played a decisive role in their seasonal succession. Eutrophication in Thane Creek favors the dominance of anti-grazing traits which increases the phytoplankton biomass through efficient resource acquisition but can encumber the energy transfer efficiency. The dominance of HAB species impedes ecosystem functioning which raises public health concerns. The strong correlation of environmental variables with phytoplankton functional structure reinforces the practical implementation of a trait-based approach for understanding phytoplankton community dynamics under varying environmental conditions.

The devil is in the details: exploring how functionally distinct round goby is among native fish in the Baltic Sea

Understanding the characteristics and conditions that make non-indigenous species (NIS) successful at establishing in recipient communities is a key in determining their potential impacts on native species, as well as to improve management actions such as prevention of future invasions. The round goby (Neogobius melanostomus) is one of the most widespread non-indigenous fish species in the Northern Hemisphere, including the coastal zones of the Baltic Sea. The impacts of round goby in the Baltic Sea are pronounced and multifaceted, yet our knowledge regarding the underlying assembly processes determining its establishment is limited. To overcome this knowledge gap, we applied a trait-based approach to assess the degree of niche overlap and functional (trait) similarity between round goby and native fish species in coastal areas from the Baltic Sea, based on the functional distinctiveness metric. Our results show that round goby is generally quite similar (or not dissimilar) to the native fish of the regional species pool, at least in terms of its overall trait composition. Conversely, round goby demonstrates pronounced differences compared to the native community in its display of parental care and territorial behaviour. Such differences in individual traits could play an important role in round goby’s invasion success in the Baltic Sea, including its interactions with native species (e.g. competition). Our results and their potential implications may be highly relevant for conservation and management if integrated within existing risk assessment tools for biological invasions in order to prioritise and enhance the effectiveness of preventative actions towards the expansion of round goby.

Identification of functional traits responsible for environmental vulnerability of Cedrus deodara in temperate forests of Western Himalaya

Climate change is impacting forest tree species adversely and making the ecological system vulnerable. The present study attempts to assess the internal vulnerability of Cedrus deodara occurring in nine sub-types of temperate forests in Western Himalaya, India via a plant functional trait-based approach. Internal vulnerability was assessed based on sensitivity and adaptive capacity through proposing an index using IPCC framework. Sensitivity was determined based on various traits (indicators) of light harvesting, carbon assimilation, nutrient content, and water budget, whereas adaptability was defined based on light harvesting efficiency, water use efficiency, resource use efficiency, and nutrient limitation. Sensitivity was maximum in Dry Deodar Forest (0.51) and Low-Level Blue Pine Forest (0.51) and minimum in Western Mixed Coniferous Forest (o.38), however adaptability was maximum in Kharsu Oak Forest (0.65) and Moist Deodar Forest-II (0.65) with minimum adaptability for Ban Oak Forest (0.53). In Ban Oak Forest, Low-Level Blue Pine Forest and Moist Deodar Forest-II high stomatal conductance compensates the low chlorophyll achieving homeostasis state for photosynthesis. Negative minimum temperature (-6.95 to −2.04 °C) in winters followed by high monsoon rainfall (417.74 to 1256.13 mm) causes high sensitivity amongst the C. deodara population in Low Level Blue Pine Forest, Dry Deodar Forest and Moist Deodar Forest-II; and adaptability was majorly affected by water availability i.e., excessive monsoon rainfall in Ban Oak Forest (1962.45 mm) and least rainfall in Neoza Pine Forest (349.50 mm). Overall, the vulnerability was high in Low Level Blue Pine Forest (0.46), Ban Oak Forest (0.45) and Dry Deodar Forest (0.45). Present study identified key traits for species vulnerability therefore management intervention should orient towards those silvicultural operations which may reduce relative water use of the species and may also facilitate for improved photosynthesis i.e., through water provision and density management of the C. deodara dominated forests in Himalayan region. The study concludes that a unified approach for managing species of the forest may be disadvantageous and detrimental to forest conservation. Rather site-specific management approach, which led to incremental response to the identified traits may support the conservation of species.

A feedback loop between management, intraspecific trait variation and harvesting practices.

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.

Bridging the Gaps: Exploring Aquatic–Terrestrial Connectivity through the Trait-Based Ecology of Riparian Predatory Arthropods

Riparian predatory arthropods represent one of the main trophic links between lotic and terrestrial ecosystems along riverine landscapes. The use of the trait-based approach promises to enhance our understanding of how these predatory communities interact with their environment through their response to various drivers of change and through their trophic interactions. We reviewed the scientific literature focused on the interaction between drivers of community change (natural and anthropogenic) and the functional traits and functional diversity components that characterize riparian ground beetles and spiders and, ultimately, on their role as cross-ecosystem trophic links. We highlight land use changes and river regulations as the strongest drivers that change the communities we study, often through various interacting mechanisms that favor the replacement of riparian specialists with generalist species, thus altering aquatic–terrestrial connectivity and the resilience of riverine arthropod consumers. Tropical regions and traits related to community responses to extreme climatic events (e.g., submersion tolerance and desiccation resistance) are less studied, while inconsistent patterns are noticed for well-studied traits, especially for spiders (e.g., their feeding preference response to aquatic subsidy availability and their body size response to flooding and bank hydrological connectivity). Future research should focus on the aforementioned drivers and knowledge gaps, along with the functional diversity changes in predatory arthropod communities along environmental and anthropogenic impact gradients, in order to improve riparian conservation.

Changes in the Functional Role of the Tejo Estuary (Portugal, Europe) According to Fish Ecological Guilds

Estuaries are extremely productive ecosystems, providing habitats for numerous aquatic species and crucial ecological services. The Tejo estuary, one of the largest European estuaries, has been thoroughly studied, and its important functional role as a nursery for several commercially important fish species is already established. In the present work, a trait-based approach was applied to functionally describe the fish community structure of the Tejo estuary and to enlighten potential changes in the ecosystem functioning at this level, following environmental changes expected to occur. To predict the distribution of species from the two most representative ecological guilds of the Tejo estuary, estuarine residents and marine migrants, species distribution models were built using an ensemble technique (combining forecasts of single models). The predictions obtained were more accurate for the marine migrants and the species distribution was strongly related with salinity, whereas estuarine species, were also influenced by depth, habitat type and river flow. The potential distributions of these ecological guilds showed that marine migrants will tend to use upstream areas in the estuary, where salinity is lower. Nonetheless, salinity is expected to increase as extreme weather events such as droughts tend to occur more frequently, decreasing favorable habitat availability for these species, and thus threatening the crucial role this ecosystem plays for these species.

The joy of being frightened: Fear experience in psychopathy.

Psychopathic traits are associated with abnormalities in fear processing. While traditional theories focus on a lack of fear, Hosker-Field etal. (2016) provided a new perspective. They suggested that individuals with elevated psychopathic traits may experience threatening situations with appreciation or positivity, resulting in reduced negative fear responses and heightened positive responses (fear enjoyment hypothesis, FEH). Our study aimed to refine Hosker-Field etal.'s (2016) study design, addressing methodological limitations and improving the inconsistent operationalization of fear experience in the literature. In an online sample of 353 participants from the general population, we examined the relationship between the FEH and relevant psychopathic traits, specifically those derived from the PCL-R framework (i.e., SRP 4 Factor 1), and from a more trait-based approach to psychopathy with assumed links to fearlessness (i.e., TriPM Boldness). By employing linear mixed effect models, we extended Hosker-Field etal.'s correlational analysis and provided further evidence for the FEH, particularly in relation to psychopathic traits measured using the PCL-R framework. The results regarding Boldness, however, are somewhat inconclusive. The present study enhances existing research on fear deficits in psychopathy by assessing the subjective experience of individuals facing threat.

Highly structured populations of deep-sea copepods associated with hydrothermal vents across the Southwest Pacific, despite contrasting life history traits

Hydrothermal vents are extreme environments, where abundant communities of copepods with contrasting life history traits co-exist along hydrothermal gradients. Here, we discuss how these traits may contribute to the observed differences in molecular diversity and population genetic structure. Samples were collected from vent locations across the globe including active ridges and back-arc basins and compared to existing deep-sea hydrothermal vent and shallow water data, covering a total of 22 vents and 3 non-vent sites. A total of 806 sequences of mtDNA from the Cox1 gene were used to reconstruct the phylogeny, haplotypic relationship and demography within vent endemic copepods (Dirivultidae, Stygiopontius spp.) and non-vent-endemic copepods (Ameiridae, Miraciidae and Laophontidae). A species complex within Stygiopontius lauensis was studied across five pacific back-arc basins at eight hydrothermal vent fields, with cryptic species being restricted to the basins they were sampled from. Copepod populations from the Lau, North Fiji and Woodlark basins are undergoing demographic expansion, possibly linked to an increase in hydrothermal activity in the last 10 kya. Highly structured populations of Amphiascus aff. varians 2 were also observed from the Lau to the Woodlark basins with populations also undergoing expansion. Less abundant harpacticoids exhibit little to no population structure and stable populations. This study suggests that similarities in genetic structure and demography may arise in vent-associated copepods despite having different life history traits. As structured meta-populations may be at risk of local extinction should major anthropogenic impacts, such as deep-sea mining, occur, we highlight the importance of incorporating a trait-based approach to investigate patterns of genetic connectivity and demography, particularly regarding area-based management tools and environmental management plans.

Long-term trends in functional diversity of exploited marine fish in the Azores’ archipelago: past and present

IntroductionEffective fisheries management requires monitoring and quantifying changes in exploited fish communities. Concerns about global fisheries sustainability have led to innovative approaches. Functional diversity, rooted in ecological theory, offers valuable insights into fishery activities and ecosystem processes. A trait-based approach was used to investigate the functional diversity of landed fish species in the Azores archipelago from 1980 to 2021.MethodsLandings data of exploited Actinopterygii and Elasmobranchii were provided by the Azores Fisheries Auction Services (LOTAÇOR/OKEANOS-UAc Fisheries Database). A trait matrix was built, incorporating 12 functional traits assigned to each species, capturing their importance in marine ecological processes. The Quickhull algorithm for convex hull was employed to calculate the volume occupied by the species in the four-dimensional functional space. Functional diversity (FD) was measured using three indices: functional richness (FRic), functional evenness (FEve), and functional divergence (FDiv). Trends in FD indices over the past 42 years were visualized using Generalized Additive Models (GAM) with interaction terms.Results and discussionGAM analysis revealed significant variations in the functional space and FD metrics over time. FRic exhibited peaks in the 1980s and 2010s, declining in the 1990s and from the 2010s onwards, indicating diversification in target species. The recent decrease in FRic can be attributed to the absence of catches of species with unique traits. The distribution of landings and trait combinations showed higher regularity in the functional space during the 1980s and 1990s (high FEve). Actinopterygii species targeted in the 1980s and 1990s had lower trait divergence (low FDiv) compared to those targeted from the 2000s onwards (high FDiv). Variability in FD can be linked to changes in fishing practices, species availability, market demand, environmental factors, and local regulations. This study underscores the importance of considering FD metrics alongside species richness and abundance when assessing the potential effects of fisheries on marine ecosystems and sustainable use of fishery resources.

Selection and development of superior strains through functional trait-based approach in agarophytic red alga Gracilaria dura (Rhodophyta)

Aim: Gracilaria dura, a red agarophyte, is known for its high-quality agarose content and holds significant potential for commercial applications in aquaculture-related industries. The successful commercial utilization of seaweeds relies heavily on obtaining high-quality seed material with commercially valuable traits. Methodology: This study focuses on employing a functional trait-based approach to develop superior strains of G. dura for commercial aquaculture in India. Cultivation through an open sea farm, variations in growth, agar yield, pigments, antioxidant capacity, and primary productivity among the strains were observed. Results: The daily growth rate ranged from 0.5 to 3.5% per day, while pigment content exhibited variations in the Chlorophyll-a, R-Phycocyanin, and R-Phycoerythrin contents. Antioxidant capacity and gross primary productivity also displayed diverse ranges. From a total of 38 strains of G. dura, three were selected based on their growth and other functional traits, namely ADI0221201, VER0220090, and ADI0221202. Positive correlations were identified between growth and regeneration, as well as growth and Chl-a. Agar content showed a positive association with antioxidant capacity and productivity. 1H NMR analysis identified 12 metabolites as potential biomarkers for G. dura growth. Interpretation: All three selected strains hold promise for future commercial cultivation of Gracilaria dura. Furthermore, six additional strains were selected based on their higher growth and agar yield for targeted breeding and hybridization to enhance desirable traits. Key words: Agarophyte, Aquaculture, Functional traits, Growth, Gracilaria dura, Strain selection

Changes in crop trait plasticity with domestication history: Management practices matter.

Crop domestication has led to the development of distinct trait syndromes, a series of constrained plant trait trade-offs to maximize yield in high-input agricultural environments, and potentially constrained trait plasticity. Yet, with the ongoing transition to organic and diversified agroecosystems, which create more heterogeneous nutrient availability, this constrained plasticity, especially in root functional traits, may be undesirable for nutrient acquisition. Such agricultural systems require a nuanced understanding of the soil-crop continuum under organic amendments and with intercropping, and the role crop genetic resources play in governing nutrient management and design. In this study, we use a functional traits lens to determine if crops with a range of domestication histories express different functional trait plasticity and how this expression changes with soil amendments and intercropping. We utilize a common garden experiment including five wheat (Triticum aestivum) varietals with a range of domestication histories planted in a factorial combination with amendment type (organic and inorganic) and cropping design (monoculture or intercropped with soybean). We use bivariate, multivariate and trait space analyses to quantify trait variation and plasticity in five leaf and five root functional traits. Almost all leaf and root traits varied among varieties. Yet, amendment type was nearly inconsequential for explaining trait expression across varieties. However, intercropping was linked to significant differences in root acquisitive strategies, regardless of the varietals' distinct history. Our findings show substantial leaf and root trait plasticity, with roots expressing greater trait space occupation with domestication, but also the strong role of management in crop trait expression. We underscore the utility of a functional trait-based approach to understand plant-soil dynamics with organic amendments, as well as the role of crop genetic histories in the successful transition to low-input and diversified agroecosystems.

Psychopathy and antisocial personality disorder in the fifth edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders: An attempted replication of Wygant et al. (2016).

The fifth edition of the American Psychiatric Association's (APA) Diagnostic and Statistical Manual of Mental Disorders (DSM-5) Section III Alternative Model of Personality Disorder (AMPD) was developed to ameliorate some of the concerns of the DSM-5 Section II categorical model by moving away from the discrete boundaries of behaviorally specific criteria to a hybridized dimensional trait-based approach. Wygant et al. (2016) examined the extent to which the AMPD improved the operationalization of antisocial personality disorder to more closely align with psychopathy, a notable weakness of DSM-5 Section II (Crego & Widiger, 2015; Lynam & Vachon, 2012; Strickland et al., 2013). Wygant et al. found that the DSM-5 Section III AMPD outperformed Section II in predicting various operationalizations of psychopathy in a sample of 200 male inmates. In the spirit of the importance in exploring replication (Tackett et al., 2017), the current study sought to replicate and extend these findings by comparing the ability of the AMPD and alternative trait models to account for psychopathy. Analyses showed a partial replication of Wygant et al.'s findings, indicating that additional traits to account for psychopathy should be included in DSM-5 Section III. The current study was not preregistered. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Functional diversity does not explain the co-occurrence of non-native species within a flow-modified African river system.

Globally, there is growing concern on the occurrence of multiple non-native species within invaded habitats. Proliferation of multiple non-native species together with anthropogenic-driven habitat modifications raise questions on the mechanisms facilitating the co-occurrence of these species and their potential impact within the recipient systems. Using the Great Fish River system (South Africa) which is anthropogenically-modified by inter-basin water transfer (IBWT), as a case study, this research employed trait-based approaches to explore patterns associated with the co-occurrence of multiple non-native fish species. This was achieved by investigating the role of functional diversity of non-native and native fishes in relation to their composition, distribution and environmental relationships. Nineteen functional traits that defined two broad ecological attributes (habitat use and feeding) were determined for 13 fish species that comprised eight native and five non-native fishes. We used these data to, firstly, evaluate functional diversity patterns and to compare functional traits of native and non-native fishes in the Great Fish River system. Secondly, we employed multivariate ordination analyses (factor analysis, RLQ and fourth-corner analyses) to investigate interspecific trait variations and potential species-trait-environmental relationships. From a functional diversity perspective, there were no significant differences in most functional diversity indices between native and non-native species. Despite interspecific variation in body morphology-related traits, we also found no clear separation between native and non-native species based on the ordination analysis of the functional traits. Furthermore, while RLQ ordination showed broad spatial patterns, the fourth-corner analyses revealed no significant relationships among species distribution, functional traits and environmental variables. The weak species-trait-environment relationship observed in this study suggests that environmental filtering was likely a poor determinant of functional trait structure within the Great Fish River. Modification of the natural flow regime may have weakened the relationship between species traits and the environment as has been shown in other systems.

Major shift in the copepod functional community of the southern North Sea and potential environmental drivers

Abstract Copepods form the bulk of secondary production in marine ecosystems and are a major resource for higher trophic levels. Copepods are highly sensitive to environmental changes as they are ectotherms with a short life span whose metabolism and development depend on abiotic conditions. In turn, changes in their functional structure (i.e. functional trait composition) can have impacts on ecosystems. We examined changes in the copepod functional community in the North Sea over the past five decades, using a trait-based approach. We observed a shift around 1986–1988: the copepod community was initially dominated by larger herbivores, with a long development time, diapause ability, and highest abundances in summer. This community changed abruptly after 1986–1988, to a dominance of smaller carnivore taxa, with shorter development times, less ability to enter diapause, and that display higher abundances in autumn. This rapid reorganization could be driven by higher water temperatures, lower dinoflagellate abundances, and lower nutrient concentrations. These changes could impact adjacent trophic levels, such as phytoplankton on which several species graze or fish larvae, leading to a mismatch situation with consequences for fish recruitment. Our results emphasize the impact that global and regional changes could have on coastal ecosystems through the role played by copepods.

Changes in Leaf Functional Traits Driven by Environmental Filtration in Different Monsoon Tropical Forest Types

Disturbances have created heterogeneous habitats for secondary and old-growth forests. Under the assumption that ecologically similar species have similar functional traits, numerous studies have attempted to use trait-based approaches to infer the abiotic and biotic factors that drive variations in community composition across different forests. However, the relative importance of these drivers in monsoon forests remains poorly understood. In this study, we randomly selected 86 plots and classified them into three forest types according to environmental factors: 1—secondary forests: secondary forest habitats at high elevation; 2—ecotone forests: general recovery and elevation; and 3—old growth forests: old growth at low elevations. We then compared the species and six leaf functional trait variations across the three forests and assessed their relationships with 15 environmental factors. The results showed that secondary and ecotone forests with a conservative strategy, exhibiting high dry matter content and leaf carbon content, tended to persist in stressful habitats, such as nutrient-poor soil, whereas old growth forests invested in trait values related to rapid resource acquisition with high specific leaf area, leaf nitrogen content, leaf phosphorous content, and leaf potassium content. Species with functional trait values between the secondary, ecotone, and old growth forests had clear signatures of their different strategies to persist in assemblages under distinct and opposite environmental filters. These plots were classified into three forest types according to environmental factors: (1) secondary forest at high elevation; (2) ecotone forests at general elevation; and (3) old growth forests at low elevation. Recovery time and elevation, followed by soil nutrients and light capture, were the most important factors shaping species and functional trait variations across forests. These results have demonstrated that environmental filters select plant species with distinct traits and ecological strategies. Acquisitive traits indicate higher competitive ability and faster resource acquisition for forest species that occur in areas with high soil fertility. Meanwhile, conservative traits promote the resistance of secondary species to environmental stressors in low soil fertility, suggesting that analyzing leaf functional-based trait variations to understand plant ecological strategies along an environmental gradient may improve understanding of forest dynamics in tropical monsoon forests.

A trait-based approach to assess niche overlap and functional distinctiveness between non-indigenous and native species.

Our understanding of the community assembly processes acting on non-indigenous species (NIS), as well as the relationship with native species is limited, especially in marine ecosystems. To overcome this knowledge gap we here develop a trait-based approach based on the functional distinctiveness metric to assess niche overlap between NIS and native species, using high-resolution data on benthic invertebrate communities in the Baltic Sea. Our results show that NIS retain a certain degree of similarity with native species, but display one or a few singular unique traits (e.g., bioturbation ability). Furthermore, we demonstrate that community assembly processes, including both environmental filtering and limiting similarity affect NIS establishment, but that their effects may be highly context dependent, as illustrated by pronounced spatial patterns in distinctiveness. Finally, our trait-based approach provides a generic framework applicable to other areas and organisms, to better understand and address biological invasions.

Congruence between vascular plants and bryophytes in response to ecological conditions in sustainably managed temperate forests (taxonomic- and trait-based levels)

Vascular plant species (VP) and bryophytes (B) constitute a significant portion of forest biodiversity and respond to both management intensity and natural disturbances within forests. In this study, we investigated the cross-taxa congruence between understorey VP and B at both diversity and composition levels across a wide range of sustainably managed forests in Slovenia. The taxonomic and functional characteristics of the selected plant groups were studied, with a particular emphasis on ground-dwelling species. We employed a trait-based approach to examine the functional characteristics. On average, the species richness of B in sustainably managed temperate forests increased with the corresponding number of VP. Furthermore, a moderate positive correlation in species composition between the studied groups of ground-dwelling organisms was also observed. The ground-dwelling VP and B were congruent in terms of trait-based composition, which was influenced by soil reaction and nutrients and light availability, while trait-based diversity was only slightly similar in response to moisture. A negative correlation between the composition of stress-tolerant VP and B hemeroby was found, indicating forest environments with a low level of disturbance. This is likely due to the sustainable management of Slovenian forests, where climate change and natural disturbances have intensified in recent years. A cross-taxon comparison of the two groups at four different levels, namely taxonomic-based diversity and composition and trait-based diversity and composition, revealed varying degrees of congruence. It is therefore important to monitor the status and temporal trends of both groups from different aspects to draw reliable conclusions.

Untangling the impact of plantation type and functional traits on ecosystem nutrient stocks in an experimentally restored forest ecosystem

The primary objective of ecological restoration is recovering biodiversity and ecosystem functioning. While a functional trait-based approach can help understand community assembly and ecosystem function recovery during ecological restoration, there still exists a knowledge gap in assessing how functional traits indicate the mediating roles of the plant community in response to forest restoration effects on ecosystem functions. This study applied the “response-effect trait” framework to investigate experimentally whether the treatment of plantation type has an impact on community trait compositions, which in turn could affect forest ecosystem nutrient stocks – here, carbon (C) and nitrogen (N) and phosphorus (P) stocks in tree, understory, litter and soil pools at an experimental station in subtropical China. We used structural equation models (SEMs) to examine the relationships among plantation type, community weighted mean of traits, and nutrient stocks in each pool. Our results show that most of the tree and understory traits studied were response traits to plantation type. Moreover, certain traits played a significant role in mediating plantation-type effects on C, N and P stocks for understory pool (e.g., understory stem specific density and specific leaf area, tree leaf phosphorus content), and for litter and soil pools (e.g., tree leaf carbon or phosphorus content, understory specific leaf area, leaf nitrogen or phosphorus content), known as “response-effect traits”. For the tree pool, only effect traits, and no “response-effect” tree traits, were found for the N stock. Total effects of SEMs indicated that, understory or tree traits can have a greater impact than plantation type on understory or litter C, N or P stocks. After approximately 35 years of natural restoration, exotic plantations exhibited a different community trait characteristic from native plantations. The important roles of traits in mediating the effects of plantation type on non-tree pool C, N and P stocks were highlighted.

Trait-based approach of aquatic insects to track recovery of wetland ecosystems in Northeast China

Wetland restoration has received increasing attention to compensate for the continuing loss of natural wetlands and revive biodiversity and associated ecological functions. The development of methods for assessing the effectiveness of restoration measures is important for wetland management. However, most studies assessing restoration success in freshwater ecosystems are based on taxonomic biodiversity; trait-based approaches remain limited, particularly in wetland ecosystems. Here, we assess the effectiveness of wetland restoration in the Sanjiang Plain, Northeast China, based on the trait composition and functional diversity of aquatic insect assemblages. We found that functional richness in restored wetlands was significantly higher than impacted wetlands but lower than natural wetlands. Compared to natural wetlands, functional beta diversity of impacted wetlands was higher. In terms of dissimilarity between wetland types, trait composition of aquatic insects in restored wetlands showed a higher similarity to natural wetlands compared to those in impacted wetlands. Trait compositions of aquatic insect assemblages in restored wetlands were more similar to impacted wetlands in May but showed a greater similarity to natural wetlands in October. Our study shows that restoration measures have facilitated the partial recovery of functional diversity and trait composition of aquatic insect assemblages in the Sanjiang Plain wetlands. Our study confirms the potential of using trait-based approach to assess the effectiveness of wetland restoration. Given that assessments based on taxonomic and trait data can provide complementary information, we recommend incorporating both taxonomic and functional metrics and considering seasonal dynamics of wetlands in post-restoration monitoring and assessment in wetlands.

Anticipated impacts of climate change on the structure and function of phytobenthos in freshwater lakes

Climate change threatens surface waters worldwide, especially shallow lakes where one of the expected consequences is a sharp increase in their water temperatures. Phytobenthos is an essential, but still less studied component of aquatic ecosystems, and it would be important to learn more about how global warming will affect this community in shallow lakes. In this research, the effects of different climate change scenarios (SSP2-4.5 and SSP5-8.5, as intermediate and high emission scenarios) on the structure and function of the entire phytobenthos community using species- and trait-based approaches were experimentally investigated in an outdoor mesocosm system. Our results show that the forecasted 3 °C increase in temperature will already exert significant impacts on the benthic algal community by (1) altering its species and (2) trait composition (smaller cell size, lower abundance of colonial and higher of filamentous forms); (3) decreasing Shannon diversity; and (4) enhancing the variability of the community. Higher increase in the temperature (+5 °C) will imply more drastic alterations in freshwater phytobenthos by (1) inducing very high variability in species composition and compositional changes even in phylum level (towards higher abundance of Cyanobacteria and Chlorophyta at the expense of Bacillariophyta); (2) continuing shift in trait composition (benefits for smaller cell volume, filamentous life-forms, non-motile and weakly attached taxa); (3) further reducing the functional diversity; (4) increasing biofilm thickness (1.4 μm/°C) and (5) decreasing maximum quantum yield of photosystem II. In conclusion, already the intermediate emission scenario will predictably induce high risk in biodiversity issues, the high emission scenario will imply drastic impacts on the benthic algae endangering even the function of the ecosystem.