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This study aimed to determine the impact of various pressures on the functional composition of OCH (Odonata, Coleoptera, and Heteroptera) in streams within the northwest Rif region of Morocco. We examined how OCH traits respond to human-induced pressures in selected stream sites in Morocco’s northwestern Rif region. OCH specimens were collected from 36 sites using a Surber sampler with dimension of 20 × 20 cm and mesh size of 500 µm over the course of two years, from 2021 to 2023. We measured physico-chemical and hydraulic parameters such as temperature, pH, DO, and NO-3. Sixty-seven trait attributes from 11 trait classes were assigned to the collected OCH taxa at the family level. Following the delineation of sites along the gradient of impacts in the study area, we categorized 7 sites as slightly impacted sites (SISs), 19 sites as moderately impacted sites (MISs), and 10 sites as heavily impacted sites (HISs). We successfully identified and categorized the traits as either vulnerable or tolerant based on RLQ models. Traits such as reproductive cycles per year and tegument respiration, which were positively correlated with SISs in the RLQ model and also positively correlated with depth and chlorine, were identified as vulnerable traits. Crawling locomotion and full water swimming were identified as tolerant traits. The distribution patterns of the OCH taxa revealed a robust correlation between the taxa and the sampling sites. Notably, taxa such as Nepidae, Naucoridae, and Corixidae exhibited widespread distribution and a strong association with the SISs. On the other hand, traits related to living macroinvertebrate food sources and reproduction in vegetation, specifically clutches, exhibited a negative correlation with total dissolved solids. Incorporating OCH functional traits into biomonitoring programs allows for a more comprehensive assessment of river ecosystems. This approach provides a nuanced understanding of how different stressors impact the community composition and overall ecological health.

Herbivorous fish can mediate spatial competition between algae and corals, which is crucial for coral ecosystems. However, in areas with limited coral coverage like the Mexican tropical Pacific (MTP), this dynamic is not fully understood. This study, using a functional trait approach and ordination analysis, explores whether herbivorous reef fish assemblage influences the benthic habitat components or if physicochemical factors define the habitat variability in the MTP's Cleofas and Marietas insular systems. We analyzed if this relationship persisted across systems and over time, and identified species traits tied to habitat variability. Island comparison analyses between Cleofas and Marietas reveal that both herbivorous reef fish and physicochemical variables shape the habitat. Cleofas had larger mobile herbivorous fish that formed groups related mostly to macroalgae cover. In contrast, temporal analysis of Marietas shows that the habitat is primarily shaped by physicochemical variables with herbivorous fish being mainly small farmer species related to branching corals. Notably, these closely situated insular systems present varied ecosystem mediators, influenced by diverse drivers including fish traits and environmental factors. This study underscores the potential of employing a framework of ecological species traits combined with ordination methods to unravel the distinct site dynamics that contribute to the persistence of coral ecosystems within the MTP. [ABSTRACT FROM AUTHOR]

This study aimed to determine the impact of various pressures on the functional composition of OCH (Odonata, Coleoptera, and Heteroptera) in streams within the northwest Rif region of Morocco. We examined how OCH traits respond to human-induced pressures in selected stream sites in Morocco's northwestern Rif region. OCH specimens were collected from 36 sites using a Surber sampler with dimension of 20 × 20 cm and mesh size of 500 µm over the course of two years, from 2021 to 2023. We measured physico-chemical and hydraulic parameters such as temperature, pH, DO, and NO-3. Sixty-seven trait attributes from 11 trait classes were assigned to the collected OCH taxa at the family level. Following the delineation of sites along the gradient of impacts in the study area, we categorized 7 sites as slightly impacted sites (SISs), 19 sites as moderately impacted sites (MISs), and 10 sites as heavily impacted sites (HISs). We successfully identified and categorized the traits as either vulnerable or tolerant based on RLQ models. Traits such as reproductive cycles per year and tegument respiration, which were positively correlated with SISs in the RLQ model and also positively correlated with depth and chlorine, were identified as vulnerable traits. Crawling locomotion and full water swimming were identified as tolerant traits. The distribution patterns of the OCH taxa revealed a robust correlation between the taxa and the sampling sites. Notably, taxa such as Nepidae, Naucoridae, and Corixidae exhibited widespread distribution and a strong association with the SISs. On the other hand, traits related to living macroinvertebrate food sources and reproduction in vegetation, specifically clutches, exhibited a negative correlation with total dissolved solids. Incorporating OCH functional traits into biomonitoring programs allows for a more comprehensive assessment of river ecosystems. This approach provides a nuanced understanding of how different stressors impact the community composition and overall ecological health. [ABSTRACT FROM AUTHOR]

The analysis of plant trait composition has raised significant interest among freshwater ecologists as a complementary approach for assessing the effects of environmental change on ecosystem functions. In this study, we investigated patterns of functional traits of the aquatic macrophyte assemblages of 74 lotic ecosystems of Greece, and we identified associations between species traits and environmental variables (hydromorphological and physicochemical parameters) through testing the hypothesis that the environmental features determine the spatial structure of traits. We allocated 12 traits to a total of 39 hydrophyte species, and we conducted RLQ and fourth corner analysis to explore relationships between species, trait composition, and environmental gradients. Based on the results of the RLQ, a hierarchical cluster analysis was conducted to identify groups of plants that share common trait characteristics. Plants were discriminated into five discrete groups based mostly on their life form (e.g., free-floating, rooted submerged etc.) and their ecological preference for nitrogen levels. Hydromorphological parameters had a higher contribution than physicochemical variables in explaining the total variance of the trait data, with water abstraction, channel substrate, and hydrologic alteration being the most important. Our analysis did not reveal significant bivariate relationships between single traits and environmental parameters, although the five groups of macrophyte assemblages appeared to associate with certain environmental gradients. Free-floating and emergent plants were related to higher concentrations of nutrients, whereas rooted submerged plants were related to higher oxygen concentration and increased pH. In addition, free-floating plants were highly associated with metrics of hydromorphological change. Our findings showed clear discrimination of macrophytes based on their functional composition and association of traits with environmental gradients. Thus, further research could explore whether macrophyte functional groups can serve as indicators of environmental change and the overall ecosystem health. [ABSTRACT FROM AUTHOR]

In the Arctic, climate-driven alterations to the quality and quantity of organic matter reaching the seafloor will likely affect benthic food web function. We used biomass-weighted diversity measures based on trophic traits (those related to feeding behaviours, e.g., mobility, size, food source), stable isotope ratios (δ15N and δ13C), and taxonomy to assess linkages between benthic food web structure and indicators of food supply in the shelf and slope ecosystems of the Canadian Beaufort Sea and Amundsen Gulf (down to 500 m). Benthic communities across both regions used a similar diversity of sedimentary organic matter sources according to stable isotopes, despite known differences between regions in organic matter input and benthic–pelagic coupling. Shelf-edge and upper-slope communities exhibited relatively high trophic trait diversity, which likely reflected the exploitation of pulsed food inputs associated with dynamic processes at the shelf break that affect the production and advection of organic matter to the benthos. Pairwise relationships between trophic traits and sedimentary proxies of benthic food supply were not significant at the regional scale. However, cluster analyses supported the notion that trophic trait composition was influenced by proximity to the shelf edge, where food supply is influenced by episodic events that may not be reflected by in situ sedimentary proxies. Our findings add to growing evidence that evaluating trophic traits composition may provide more information regarding functional responses to changes in benthic food supply than either isotopic or taxonomic diversity indices alone.

Anthropogenic pollution from urban and agricultural activities continually affects freshwater ecosystems in Africa, adversely affecting water quality and biodiversity. In this study, we explored the responses of macroinvertebrate functional feeding groups (FFGs) to an urban-agricultural disturbance in the Niger Delta Region, aiming to examine their utility for long-term monitoring of urban-agricultural disturbance in the region. We sampled 17 sites in 11 rivers between 2008 and 2012. We classified the sites into urban, agricultural, and reference (control) sites based on the watershed land-uses and reach-scale anthropogenic disturbance. Permutational multivariate analysis of variance showed that physical and chemical variables differed significantly between the site groups (P < 0.05) across the land-use types in the study area. Multivariate analysis of similarity (ANOSIM) indicated that urban land-use had more effect on FFGs than agricultural activities, differing significantly from the forested sites (P < 0.05). Macroinvertebrate FFGs such as collectors-filter, collector-gatherers, and scrapers/grazers were identified as sensitive FFGs of urban-agricultural pollution. These FFGs showed strong negative associations with physical and chemical indicators increasing urban-agricultural pollution (e.g. conductivity, nutrients, and turbidity) and favoured by DO at the reference sites. Conversely, shredders and predators were tolerant, indicating significant positive associations with increasing urban-agricultural pollution. They were associated with variables such as temperature, BOD and nitrates. Overall, this study revealed that urban and agricultural pollution differentially affected macroinvertebrate functional feeding groups, and indicator FFGs were identified. This provided further insights on urban-agricultural land-use effects on Afrotropical riverine systems and using FFGs as reliable indicators of ecosystem integrity. [ABSTRACT FROM AUTHOR]

Seabirds are top predators in coastal and pelagic ecosystems that forage at sea but return to land regularly during the breeding season (i.e., central place foragers). This unique life history strategy is directly related to their biological traits and helps define their role as top predators in marine systems. We analysed the effects of physiographic characteristics of nesting islands (area, elevation, and distance from the continent, as predicted by the General Dynamic Model of Oceanic Island Biogeography) and oceanographic variables from waters surrounding nesting islands that tend to be characterised by steep gradients (temperature, salinity, and primary productivity) on the trait diversity of nesting seabird assemblages on islands of the south-eastern Pacific Ocean. Four biological traits related to species’ life history and feeding strategy were used to calculate two indices, the Functional Richness and Rao’s Quadratic entropy. We used fourth-corner and RLQ analysis to determine the relationship between biological traits and environmental variables. Island physiography and primary productivity in the waters surrounding nesting islands significantly affected seabird trait diversity, which gradually decreased from Chilean coastal islands to the distant Polynesian Islands. The traits for body mass and clutch size showed a significant positive relationship with primary productivity. We identified three assemblages of seabirds that had contrasting trait structures. These were defined as the Galapagos, Coastal Chile, and south-eastern Oceanic islands assemblages, and reflected the adaptations of three different species pools to specific oceanographic conditions. Our results suggest that food-related constraints might be one of the most critical environmental filters that shaped the current trait structure of nesting seabird assemblages on the islands in the eastern South Pacific Ocean.

Heterogeneity in riverine habitats acts as a template for species evolution that influences river communities at different spatio‐temporal scales. Although birds are conspicuous elements of these communities, the roles of phylogeny, functional traits, and habitat character in their niche use or species' assembly have seldom been investigated. We explored these themes by surveying multiple headwaters over 3000 m of elevation in the Himalayan Mountains of India where the specialist birds of montane rivers reach their greatest diversity on Earth. After ordinating community composition, species traits, and habitat character, we investigated whether river bird traits varied with elevation in ways that were constrained or independent of phylogeny, hypothesizing that trait patterns reflect environmental filtering. Community composition and trait representation varied strongly with increasing elevation and river naturalness as species that foraged in the river/riparian ecotone gave way to small insectivores with direct trophic dependence on the river or its immediate channel. These trends were influenced strongly by phylogeny as communities became more clustered by functional traits at a higher elevation. Phylogenetic signals varied among traits, however, and were reflected in body mass, bill size, and tarsus length more than in body size, tail length, and breeding strategy. These variations imply that community assembly in high‐altitude river birds reflects a blend of phylogenetic constraint and habitat filtering coupled with some proximate niche‐based moulding of trait character. We suggest that the regional co‐existence of river birds in the Himalaya is facilitated by this same array of factors that together reflect the highly heterogeneous template of river habitats provided by these mountain headwaters. [ABSTRACT FROM AUTHOR]

The present study investigates the influence of seasonal dynamics on macrobenthic assemblages in four seasons of 2017–2018 from the central sector of Indian Sundarbans which is under the constant threat of climate change. Besides taxonomic analysis, a trait-based approach has also been applied to assess the change in their ecosystem functioning. The maximum species density (11675 ± 11883.31 ind. m−2) was observed during the spring season which declines considerably in the monsoon season (5875 ± 6224.08 ind. m−2). A total of 95 macrobenthic taxa were recorded from Sundarbans and they were dominated by families like Capitellidae, Donacidae, Magelonidae, Nereididae, Paraonidae and Spionidae. Overall, polychaetes have shown higher taxonomic and functional variation than other groups. Opportunistic polychaete species have shown a prominent compositional shift during post-monsoon seasons. Both the univariate and multivariate analyses have shown a significant relation between macrobenthic composition and environmental parameters. SIMPER has depicted that environmental parameters made the station 4 unique for several types of molluscs like Acteocina estriata, Stenothyra deltae and Meretrix meretrix during spring. Trait percentages also showed a seasonal succession pattern and among the trait categories, burrowers and deposit feeders dominated the estuary. A gradual increase in suspension feeders in spring has been noticed. RLQ approach with fourth-corner analysis was used to unravel the relationship between traits and environmental parameters. Hence, the present study provided a comprehensive idea about the species composition along with their trait categories from such a dynamic habitat. That could be the first stepping stone for a long term monitoring of macrobenthic assemblages from this largest delta on earth.

Aim: Species introductions have reshaped island faunas for the last 200 years, often threatening native biodiversity. Approximately equal numbers of native and alien species currently co‐occur in the New Zealand avifauna, but they show distinct habitat use. Antagonistic interactions, habitat affinities and legacies of introduction history may concur to explain their segregation along habitat gradients. To investigate these processes, we explored how habitat, ecological traits and introduction history relate with the current composition of bird assemblages. Location: New Zealand Taxon: Birds Methods: We analysed 917 bird point counts spread along habitat and elevation gradients in the Canterbury region, South Island and related 10 ecological traits to landscape composition using a three‐table ordination method known as "RLQ analysis", accounting for spatial autocorrelation and phylogeny. We tested whether alien species' positions in the RLQ were related to proxies of introduction history. Results: Eighteen endemic, 11 native and 19 alien species were distributed along a gradient from forest to open‐habitat assemblages, in relation to foraging mode, nesting site and body size. A second gradient segregated species between native and exotic forests according to territoriality, sedentarity and diet. Traits accounted for the separation of native and alien bird species in forests, but not in open habitats. Phylogenetic signals emerged from the separation of native and alien species by forest type, and spatial structures suggested a landscape‐level, rather than regional or local determinism. These correlations were independent of introduction history, although open‐habitat assemblages tended to host alien species introduced later in time. Main conclusions: Habitat type and resource availability explain the spatial partitioning of New Zealand bird assemblages between native and alien species more consistently than competitive exclusion. We conclude that trait‐mediated ecological differences among species have likely played a predominant role in species' segregation among landscapes, while maintaining endemic bird assemblages in native forests. [ABSTRACT FROM AUTHOR]

Headwater streams in Afromontane ecoregions harbour locally adapted aquatic communities. However, across many regions in Africa, these ecosystems and their unique aquatic biodiversity have been severely impacted by unsustainable land use practices. We tested the hypothesis that land use disturbances were the primary drivers of community dynamics by comparing spatial and temporal dynamics together with trait-environment relationships of macroinvertebrate communities in three headwater streams influenced by different land use practices. The three headwater streams were distinguished based on high conductivity, total dissolved solids and alkaline pH in the agriculture-disturbed stream, and low temperature in a stream whose riparian zone was invaded by non-native vegetation compared to a near-natural stream. Macroinvertebrate taxonomic diversity was, nevertheless, comparable among these three streams. Constrained canonical ordination revealed that seasonality was a major driver of macroinvertebrate dynamics that was reflected mostly by the abundances of six macroinvertebrate taxa (Baetis, Dicentroptelum, Afronurus, Tricorythus, Simulium and Cheumatopsyche), whereas land use contributed a small but significant difference. Trait-environment relationships reflected seasonal changes that included the importance of benthic substratum in winter, the occurrence of collector-gatherer invertebrates in spring and aerial breathing traits in summer. Land use-related traits were, nevertheless, reflected by gill respiration and grazer feeding traits represented by Afronurus in the near-natural stream, predator traits represented by Aeshna and Lestes in the invaded stream, and aerial respiration represented by Enithares, Orectogyrus and Rhagovelia in the agriculture-disturbed stream. Our results suggest that environmental variability associated with seasonality probably played a deterministic role within which land use disturbances operated. Overall, our study suggest that importance of using multiple metrics to unpack the patterns associated with land use disturbances in headwater streams.

Andean forests are home to a strikingly high diversity of plants, making it difficult to understand the main drivers of species assembly. Trait-based approaches, however, help overcome some challenges associated with high taxonomic complexity, providing insights into the main drivers of species coexistence. Here, we evaluated the roles of climate, soil fertility, and symbiotic root associations on shaping the assembly of six plant functional traits (leaf area, specific leaf area, dry leaf matter content, leaf thickness, leaf toughness, and wood density) along an elevational gradient in the species-rich northwestern Andean forests of Colombia. The two main axes of the correspondence RLQ analysis explained 95.75% of the variability. The first axis was associated with the leaf economic spectrum, while the second axis with the tradeoff between growth and survival. Furthermore, the fourth corner method showed that both regional (climatic variables) and local factors (soil fertility, symbiotic root associations, and light distribution) played a key role in determining plant trait assembly. In summary, our study emphasizes the importance of considering both individual size and local factors to better understand drivers of plant trait assembly along environmental gradients. [ABSTRACT FROM AUTHOR]

Disturbances often act as ecological filters through which only certain combinations of biological traits may pass. Here, we aimed to determine if an unprescribed human-started wildfire can act as a filter for stream-dwelling macroinvertebrates. To do this, we sampled three burnt and two reference streams in Los Alerces National Park (Patagonia, Argentine side). Sampling began shortly after the fire was extinguished and comprised four visits during the following seven months. We explored how functional richness, evenness, and dispersion at the community level responded to post-fire environmental changes using generalized linear mixed models. We also used RLQ and fourth-corner analysis to identify which trait modalities were specifically affected, either positively or negatively, by the fire. We found that functional richness and dispersion decreased with increasing disturbance intensity, which in this case, was best represented by increased suspended solids. In addition, all three functional metrics were significantly lower in fire-affected sites. Burnt streams were characterized by bi-multivoltine taxa and collector-gatherers, among others. Overall, our study showed how a wildfire can directly constrain the functional composition of macroinvertebrate communities, and highlighted the importance of incorporating trait-based approaches into the study of large-scale disturbances. [ABSTRACT FROM AUTHOR]

Andean forests are home to a strikingly high diversity of plants, making it difficult to understand the main drivers of species assembly. Trait-based approaches, however, help overcome some challenges associated with high taxonomic complexity, providing insights into the main drivers of species coexistence. Here, we evaluated the roles of climate, soil fertility, and symbiotic root associations on shaping the assembly of six plant functional traits (leaf area, specific leaf area, dry leaf matter content, leaf thickness, leaf toughness, and wood density) along an elevational gradient in the species-rich northwestern Andean forests of Colombia. The two main axes of the correspondence RLQ analysis explained 95.75% of the variability. The first axis was associated with the leaf economic spectrum, while the second axis with the tradeoff between growth and survival. Furthermore, the fourth corner method showed that both regional (climatic variables) and local factors (soil fertility, symbiotic root associations, and light distribution) played a key role in determining plant trait assembly. In summary, our study emphasizes the importance of considering both individual size and local factors to better understand drivers of plant trait assembly along environmental gradients.

Wildfires are increasing in incidence and severity across coniferous forests of the western United States, leading to changes in forest structure and wildlife habitats. Knowledge of how species respond to fire‐driven habitat changes in these landscapes is limited and generally disconnected from our understanding of adaptations that underpin responses to fire.We aimed to investigate drivers of occupancy of a diverse bat community in a fire‐altered landscape, while identifying functional traits that underpinned these relationships.We recorded bats acoustically at 83 sites (n = 249 recording nights) across the Plumas National Forest in the northern Sierra Nevada over 3 summers (2015–2017). We investigated relationships between fire regime, physiographic variables, forest structure and probability of bat occupancy for nine frequently detected species. We used fourth‐corner regression and RLQ analysis to identify ecomorphological traits driving species–environment relationships across 17 bat species. Traits included body mass; call frequency, bandwidth, and duration; and foraging strategy based on vegetation structure (open, edge, or clutter).Relationships between bat traits and fire regime were underpinned by adaptations to diverse forest structure. Bats with traits adapting them to foraging in open habitats, including emitting longer duration and narrow bandwidth calls, were associated with higher severity and more frequent fires, whereas bats with traits consistent with clutter tolerance were negatively associated with fire frequency and burn severity. Relationships between edge‐adapted bat species and fire were variable and may be influenced by prey preference or habitat configuration at a landscape scale.Predicted increases in fire frequency and severity in western US coniferous forests are likely to shift dominance in the bat community to open‐adapted species and those able to exploit postfire resource pulses (aquatic insects, beetles, and snags). Managing for pyrodiversity within the western United States is likely important for maintaining bat community diversity, as well as diversity of other biotic communities. [ABSTRACT FROM AUTHOR]

Plant functional traits and plant functional groups are increasingly used to assess the effect of the change in land use on plant species or plant communities, in nature conservation projects, to detect patterns in the expansion some invasive species or to asses the processes of succession or competition in plant communities. In this study, the main objective was to identify the main plant functional groups (based on plant traits) which co-exist in different plant communities of the dry grasslands (Festucetalia valesiacae) from North-Eastern Romania using the RLQ analysis (considering the plant traits, environment characteristics and vegetation). As RLQ analysis mainly revealed a soil moisture-soil nutrients gradient along the first axis, a transition from species with traits specific to more dry conditions and less available nutrients to moister and higher nutrients availability sites was observed (from perennial species with short flowering range and traits oriented to resources retention in storage organs to annual species with long flowering range and traits oriented to resource acquisition). Plant functional groups were identified using species scores along the first two RLQ axes via k-means clustering which generated six groups displayed along the above mentioned gradients. The floristic composition of the identified functional groups suggested that, in the context of Festucetalia valesiacae vegetation type from North-Eastern Romania, plant communities developed in areas with lower values for soil moisture and nutrients could possibly be richer in autochore and barochore geophyte and hemicryptophyte species with short flowering range and mixed reproduction type. As soil moisture and nutrients increase, in the floristic composition could possibly occur more anthropochore and zoochore therophyte species with long flowering range, mainly reproducing by seeds and, also, some taller endozoochore shrubs species.

Concern regarding global change has increased the need to understand the relationship between fire regime characteristics and the environment. Pyrogeographical theory suggests that fire regimes are constrained by climate, vegetation and fire ignition processes, but it is not obvious how fire regime characteristics are related to those factors. We used a three-matrix approach with a multivariate statistical methodology that combined an ordination method and fourth-corner analysis for hypothesis testing to investigate the relationship between fire regime characteristics and environmental gradients across Spain. Our results suggest that fire regime characteristics (i.e., density and seasonality of fire activity) are constrained primarily by direct gradients based on climate, population, and resource gradients based on forest potential productivity. Our results can be used to establish a predictive model for how fire regimes emerge in order to support fire management, particularly as global environmental changes impact fire regime characteristics. [ABSTRACT FROM AUTHOR]

Assembly rules are ecological processes imposed on a regional species bank to establish the structure of communities and define diversity patterns regarding space and time. Here, we investigated the trait distribution of periphytic algae in floodplain lakes that are naturally under contrasting environmental pressures with and without flood pulse action (low and high water phases) and the relationship between functional traits and environmental variables at regional and local scales. We hypothesized that functional clustering will be related to the low water phase in local scale, based on environment filters, and functional overdispersion to the high water phase in regional scale. With respect to traits, we can expect that the flood pulse would favored the prevalence of nanoperiphyton, filamentous forms and loosely attached. For this, we conducted a two-year assessment of the structure and dynamic of periphytic algae communities regarding their functional traits in lakes belonging to two sub-basins in a subtropical floodplain (upper Paraná River floodplain). The samplings occurred during the high water phase in 2010 and 2011 and the low water phase in 2011. The functional diversity values of the communities were quantified and compared with the mean value of communities randomly generated using null models. The relationships between functional traits and environmental variables were examined using RLQ analysis. We have shown that the traits respond to abiotic factors, and they indicated overdispersion in high water phase, and higher functional diversity in most preserved environments with absence of the pulse. The flood pulse favored the prevalence of colonial life form, stalked, entangled and heterotrichous species. This study showed spatial and temporal differences in the limnological characteristics between the lakes caused by hydrological phase and local forces in different sub-basins and the importance mainly of assimilable nutrients in the evaluation of trait–environment relationships. The overdispersion result can be assigned to flood pulse, which promotes a higher probability of dispersion and colonization of new areas for rare species, disturbance and more heterogeneous habitats, allowing opportunities for resource partitioning and regeneration of different species strategies. Moreover, the higher periphytic algae functional diversity in preserved sites emphasizes the importance of understanding ecological patterns linked to environmental degradation, as well as of conservation initiatives, because variation in periphytic algal communities implies in changes in the trophic structure, dynamics and in the functioning of environments. [ABSTRACT FROM AUTHOR]

Plant functional traits and plant functional groups are increasingly used to assess the effect of the change in land use on plant species or plant communities, in nature conservation projects, to detect patterns in the expansion some invasive species or to asses the processes of succession or competition in plant communities. In this study, the main objective was to identify the main plant functional groups (based on plant traits) which co-exist in different plant communities of the dry grasslands (Festucetalia valesiacae) from North-Eastern Romania using the RLQ analysis (considering the plant traits, environment characteristics and vegetation). As RLQ analysis mainly revealed a soil moisturesoil nutrients gradient along the first axis, a transition from species with traits specific to more dry conditions and less available nutrients to moister and higher nutrients availability sites was observed (from perennial species with short flowering range and traits oriented to resources retention in storage organs to annual species with long flowering range and traits oriented to resource acquisition). Plant functional groups were identified using species scores along the first two RLQ axes via k-means clustering which generated six groups displayed along the above mentioned gradients. The floristic composition of the identified functional groups suggested that, in the context of Festucetalia valesiacae vegetation type from North-Eastern Romania, plant communities developed in areas with lower values for soil moisture and nutrients could possibly be richer in autochore and barochore geophyte and hemicryptophyte species with short flowering range and mixed reproduction type. As soil moisture and nutrients increase, in the floristic composition could possibly occur more anthropochore and zoochore therophyte species with long flowering range, mainly reproducing by seeds and, also, some taller endozoochore shrubs species. [ABSTRACT FROM AUTHOR]

Plant functional traits have been proposed as a linkage between the environmental control of vegetation and ecosystem function. Identification of traits that mediate the response of plant species to the environment is well established, but the identification of effect traits and the linkage between the two sets is less developed. This was attempted for a study of eight contrasting land uses in a marginal agricultural landscape where data on vegetation, management controls of the disturbance regime, and soil characteristics, including nitrogen release, were measured simultaneously with measures of ecosystem function such as litter decomposition rates and primary productivity on 30 sites. Trait data were assembled from databases, and an iterative multivariate approach using the three table (species, trait, environment) method RLQ was employed to identify a parsimonious set of traits that predict plant species responses to the environment and a parsimonious set of traits that link vegetation to ecosystem function. The lists of response and effect traits were similar, and where differences were observed, traits were usually highly correlated with at least one trait in the other list. This approach identified a small number of traits (canopy height, leaf dry matter content, leaf size, and specific leaf area) that provide a means of linking vegetation responses to environmental change with changes in ecosystem function. Other response traits included vegetative spread strategy, start of flowering, and seed terminal velocity, but within the system studied these traits were all significantly correlated to the traits shared between the response and effect lists. [ABSTRACT FROM AUTHOR]

The trait-based approach aims to detect functional patterns in vegetation beyond specific sites or taxa. In most cases, plant traits are assumed to be linearly related to environmental gradients such as grazing intensity. To generalize results beyond specific sites, it is important to know to which extent environment-trait relationships are non-linear. Non-linearity can be a source of inconsistency among different studies according to length and studied portion of a gradient. In this study, we test if and to what extent traits relate non-linearly to a grazing gradient using data from a grassland-matorral interface in the Mediterranean rangeland of “La Crau” (SE France). Because quantification of grazing by itinerant sheep flocks is difficult, we use a marker plant, Phillyrea angustifolia, and several independent pasture indicators to estimate grazing intensity. First, we related traits to grazing using a multivariate three-table ordination method (RLQ), which assumes linear reactions of traits. To evaluate the importance of non-linearity, we applied generalized additive models (GAMs) to our data. This revealed that a third of traits studied here showed non-linear relationships to grazing. These non-linear responses cover a large spectrum including seed mass, life form, phenology dispersal- and leaf traits. The high part of non-linear relations compromises a general assumption of linear trait-environment relationships. Future works should therefore more often consider non-linear relationships using methods with no constraints on shape of response, e.g., GAM in the analysis of functional trait studies. In this way, non-linear relationships can reveal new aspects of species and community response to global change and deepen our understanding of trait-environment relations. [ABSTRACT FROM AUTHOR]

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The taxonomy-based response pattern of macroinvertebrates to sediment stress is well established, with tolerant taxa increasing in impacted conditions, while sensitive taxa decrease along a deteriorating water quality gradient. However, the distribution patterns of traits in response to environmental stress gradient, including suspended sediments, remain unclear, particularly in Africa, where trait-based studies are under-explored. We examined the distribution patterns of macroinvertebrate traits along a suspended sediment stress gradient and identified tolerant and sensitive traits for suspended sediment stress. We sampled macroinvertebrates and environmental variables seasonally in winter, spring, summer and autumn of 2016 to 2018 in eight selected sites in the Tsitsa River and its tributaries. We selected 12 traits and ecological preferences, resolved them into 47 trait attributes, and analysed them using the RLQ and fourth-corner analyses. Our results revealed that macroinvertebrate traits and ecological preferences were differentially influenced by fine suspended sediments in the Tsitsa River and its tributaries. Traits such as a preference for CPOM, collector-filtering, and a high sensitivity to oxygen depletion, were deemed sensitive to suspended sediments stress, exhibiting positive associations with the control sites, and negatively associated with any of the environmental parameters (sediment grain sizes, turbidity, TSS and EC). Tolerant indicator traits included a high tolerance of oxygen depletion, skating and a preference for FPOM. The fourth-corner analysis results indicated that suspended fine sediment grain sizes, (including coarse sand, fine silt and clay) were the most important variables influencing macroinvertebrate trait distribution patterns during the dry season, while gravel, mud and medium sand were more important during the wet season. Overall, our study provided critical insights towards trait-based responses of macroinvertebrates communities to suspended sediment stress, key information that could stimulate the development of macroinvertebrate trait-based biomonitoring tools for the assessment of suspended sediment stress in the Afrotropical region. [ABSTRACT FROM AUTHOR]