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Understanding species distributions and diversity gradients is a central challenge in ecology and requires prior knowledge of the functional traits mediating species' survival under particular environmental conditions. While the functional ecology of plants has been reasonably well explored, much less is known about that of animals. Ants are among the most diverse, abundant and ecologically significant organisms on earth, and they perform a great variety of ecological functions., In this study, we analyse how the functional species traits present in ant communities vary along broad gradients in climate, productivity and vegetation type in the south-western Mediterranean., To this end, we compiled one of the largest animal databases to date: it contains information on 211 local ant communities (including eight climate variables, productivity, and vegetation type) and 124 ant species, for which 10 functional traits are described. We used traits that characterize different dimensions of the ant functional niche with respect to morphology, life history and behaviour at both individual and colony level. We calculated two complementary functional trait community indices ('trait average' and 'trait dissimilarity') for each trait, and we analysed how they varied along the three different gradients using generalized least squares models that accounted for spatial autocorrelation., Our results show that productivity, vegetation type and, to a lesser extent, each climate variable per se might play an important role in shaping the occurrence of functional species traits in ant communities. Among the climate variables, temperature and precipitation seasonality had a much higher influence on functional responses than their mean values, whose effects were almost lacking., Our results suggest that strong relationships might exist between the abiotic environment and the distribution of functional traits among south-western Mediterranean ant communities. This finding indicates that functional traits may modulate the responses of ant species to the environment. Since these traits act as the link between species distributions and the environment, they could potentially be used to predict community changes under future global change scenarios. [ABSTRACT FROM AUTHOR]

Anthropogenically increased input of nitrogen (N) and phosphorous (P) have led to a severe reduction of plant species richness in European semi-natural grasslands. Although it is well established that this species loss is not trait neutral, a thorough analysis of the effects of nutrient addition on trait based functional diversity and functional composition, independently of species loss, is lacking so far. We compiled data on the plant species abundance (relevé's) of 279 Nardus grasslands from nine European countries, across a gradient of soil N and P content. Functional diversity (Petchy and Gaston's FDc, weighted FDc and quadratic entropy) and mean trait composition were calculated for each relevé, based on 21 functional traits. Differences in functional diversity and functional composition were related to differences in soil N, atmospheric N deposition, soil P and pH, while controlling for geographic location and species richness. All functional diversity measures decreased with increasing soil N, with wFDc also decreased by soil P, independent of species loss. This was accompanied by clear shifts in functional trait composition, associated with shifts from below-ground competition for nutrients to above-ground competition for light. This resulted in a decrease in insect-pollinated therophytes and chamaephytes and an increase in long-lived, clonal graminoids and hemicryptophytes under increasing soil N and P. These functional community changes can be expected to alter both ecosystem functioning and service provisioning of the studied grasslands. Our research emphasizes the importance of a reduction of both N and P emission throughout Europe for sustainable conservation of these communities. [ABSTRACT FROM AUTHOR]

Abstract: The study investigates the effect of the salinity gradient on the functional composition, functional diversity and functional redundancy of soft-bottom communities in the south-western Baltic Sea. For this purpose, three different areas were selected and compared using a biological trait approach. Functional diversity was calculated by using Rao's Quadratic Entropy as a measure and functional redundancy by the ratio between functional and species diversity. Despite a high variability due to different other occurring environmental gradients, a clear shift in functional composition was visible using the BTA approach. The changes were most distinct for the traits, longevity and larvae type if the analyses were based on the biomass of the species, whereas abundance-based analyses tend to show less clear results. Along the same gradient, functional diversity and functional redundancy tended to increase if biomass data were used in the analysis. On the other hand no changes could be observed in the functional diversity when the abundance of the species was used. The result of the BTA showed a trend from long-lived and highly specialised species towards short-lived ubiquitous species with decreasing salinity. However, dominance of ubiquitous species in brackish waters seems to buffer the functional loss. Therefore it can be followed that by gaining functional redundancy the robustness of the benthic ecosystem to environmental changes increases. [Copyright &y& Elsevier]

Understanding the impact of marine protected areas on the distribution and composition of fishes is key to the protection and management of coral reef ecosystems, and especially for fish-based activities such as SCUBA diving and recreational fishing. The aim of this research is to compare the ichthyofauna structure in three areas in the eastern part of Los Canarreos archipelago in Cuba with different management schemes: Cayo Campos-Cayo Rosario Fauna Refuge (CCCR), Cayo Largo Ecological Reserve (CL) and non-protected area (nMPA), and considering habitat differences and depth variation. A total of 131 video transects were conducted using diver operated stereo-video (stereo-DOV) in November, 2015 in backreef and forereef along the CCCR, CL and the adjacent nMPA. We recorded 84 species and 27 functional groups suggesting high complementarity of functions. Several multispecies schools were observed along surveys, which explain the biomass peaks in some sites, mainly for Lutjanidae, Haemulidae and Carangidae. A concerning issue was the bare representation of critical functional groups and threatened species. The effect of sites nested within habitats was significant and the most important driver structuring fish assemblages, while MPA condition was not evident. Favorable habitat features (habitat heterogeneity and surrounding coastal ecosystems) are likely enhancing fish assemblages and counteracting the effects of pouching derived from insufficient management. We recommend immediate actions within a strategy of precautionary management including, but not limited to, the appointment of staff for the administration of CL, frequent monitoring and effective enforcement., Competing Interests: The authors declare that they have no competing interests., (© 2022 Navarro-Martínez et al.)

Question Variability in species function is often studied by using phylogenetic relatedness as a surrogate for functional similarity between species, rather than by measuring functional traits directly. The phylogenetic-based method is far less data-intensive than trait-based methods. However, to what extent community-level variability in species function is driven by phylogenetic history has rarely been explored in terms of composition and diversity. In this paper we test this empirically by asking: do differences in the functional composition and diversity of species assemblages (i.e. plots) along an environmental gradient mirror differences in phylogenetic structure? Location Coastal dune communities of the Tyrrhenian coast of Italy. Methods We calculated fuzzy-weighted mean trait values and the Rao index for dominant species in 405 plots using 16 functional traits that were measured in the field or from other sources. Based on a phylogenetic distance matrix among species obtained from an aged phylogenetic supertree, we applied matrix correlation tested against appropriate null models to calculate how much of the plot-to-plot variability in functional composition (measured through fuzzy weighting) and diversity (measured with the Rao index) is predicted by the corresponding phylogenetic metrics. Results At the species pool level there was evidence for a phylogenetic signal in trait variation. Furthermore, we found that differences in species functional diversity among plots were closely related to their phylogenetic variability, but this was not true for functional composition. Conclusions The results show that even when there is evidence of phylogenetic trait conservatism at the species pool level, phylogeny may be unable to capture all aspects of functional community structure. This emphasizes the need for caution when interpreting measures of phylogenetic community structure as proxies of functional community structure. [ABSTRACT FROM AUTHOR]

Highlights: [•] Carabid species richness or evenness did not differ in samples separated by 24 years. [•] Carabid community and trait composition changed after mitigation of intensification. [•] More omnivorous, mobile, spring breeding, and large species were found after mitigation. [•] A functional approach provided a more mechanistic view of carabid response to land use changes. [Copyright &y& Elsevier]

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Question Do leaf functional traits describe variation in the intensity of management in semi-natural grasslands? Location Mugello, North Apennines, Italy. Methods In an ecologically homogeneous area, we identified four grassland management practices (three different stocking rates and abandonment for 10 or more years). We measured leaf functional traits ( LFT) of three dominant grass species - leaf dry matter content ( LDMC), specific leaf area ( SLA) and leaf N concentration ( LNC) - in two permanent sampling plots per treatment for two consecutive years. Statistical tests and multivariate analysis were employed to compare the traits and analyse their sensitivity in responding to the different management intensities. Results The robustness of LDMC and SLA in grass species ranking was confirmed. Weighted LDMC and SLA were able to differentiate the most intensely managed site from the others. Conclusions The results of the weighted LDMC and the weighted SLA encourage further studies aimed at the development of a LFT database for the most common grass species of Apennine semi-natural grasslands. This could be of great help in the development of indicators able to support the formulation of rational management plans for conservation and sustainable animal production. [ABSTRACT FROM AUTHOR]

Questions What is the best way to identify plant indicators for monitoring the responses of semi-natural grassland communities to various management practices (i.e. burning, burning and mowing, burning and grazing)? Can a multi-trait plant functional group ( PFG) approach extract indicator species more effectively than a single-trait approach? Location Semi-natural and artificial grasslands in the northern and eastern parts of the somma of Mt. Aso, Kumamoto Prefecture, Japan. Methods We analysed a data set from 203 semi-natural and artificial grassland vegetation plots (each 1 m × 1 m), and compared species and functional compositions among the management types and between the northern and eastern locations using non-metric multidimensional scaling ( NMDS). Potential indicator species were extracted by indicator species analysis ( INSPAN) and compared with the results of single-trait and multi-trait PFG approaches, which classify plant species into groups based on individual or combinations of traits (growth form, life span, dispersal mode, flowering season and plant height). Results Only the multi-trait PFG approach successfully clustered the vegetation plots for each management type. Semi-natural burned-and-grazed grasslands in the eastern and northern regions were characterized by a specific PFG among 21 PFGs, whereas the same three PFGs characterized the burned-and-mowed semi-natural grassland of the two regions. The extracted PFGs represent combinations of vegetative, dispersal and reproductive traits (e.g. short, wind- and animal-dispersed species for grazed semi-natural grasslands; tall, summer-flowering forbs for mowed semi-natural grasslands). As compared to indicator species extracted by the multi-trait PFG approach, INSPAN extracted additional indicator species, but some of these were inappropriate. Conclusions We identified PFGs representing each management type and characterized species adaptations to different disturbance regimes, such as mowing and grazing. Among the species extracted by INSPAN, only those classified into the representative PFGs can serve as indicators for characterizing managed semi-natural grasslands. Our findings indicate that using a multi-trait PFG approach can provide reasonable plant indicators for monitoring grassland communities throughout the regions when combined with a species-based INSPAN approach. This proposed method would contribute to the conservation of plant biodiversity in threatened semi-natural grazed and mowed grasslands. [ABSTRACT FROM AUTHOR]

In this paper, a proof is given that in design methods, the relation between technical functions and their subfunctions in functional descriptions of technical products cannot be analysed as a formal relation of parthood. This result holds for design methods in which transformations of flows of energy, material and signals are accepted as functions. First, two specific categories of such technical functions are modelled. Second, the composition relation by which ordered sets of these functions define other functions is characterised. Third, it is shown that this composition relation for technical functions does not meet the basic postulates of parthood relations as given by mereology, the theory of parthood. It still may be beneficial to designing to take subfunctions informally as the parts of the functions they compose. Yet, the proof shows that when functional descriptions are formalised for, for instance, the development of automated design reasoning tools or for incorporation in engineering ontologies, the composition relation for technical functions cannot unconditionally be taken as a parthood relation. [ABSTRACT FROM AUTHOR]

Domain-specific languages allow to raise the level of abstraction by using concepts and operations of the domain. Limited applicability of these languages requires lower development costs compared to general-purpose languages. This means that different development techniques need to be used. This work is a contribution to the field of development of domain-specific languages. It analyses the current state of the field. Special attention is given to the analysis of language composition methods and identifying widespread composition techniques. Composition is analyzed not only on the level of grammars, but also on the level of language concepts. The work presents proposed approach for language development based on the standardized generic syntax that serves the role of common substrate for developed languages. The structure of language elements is defined based on principles of functional composition extended with metaprogramming capabilities. The behavior of such language is defined using a general-purpose language that provides a connection with the outer environment. Proposed techniques allow modular language development using libraries of language elements. A prototype of the system for definition and processing of new languages was developed for experimental verification of proposed techniques. This was used for development of several languages. [ABSTRACT FROM AUTHOR]

1. Soil resource availability and disturbance are widely recognized as key drivers of plant community structure. However, the relative importance of different plant traits in determining species abundance following shifts in soil resource availability and disturbance remains little studied, particularly in long-term experiments. 2. We studied trait-based plant community assembly in a 27-year grassland experiment where 25 plant species were sown into resident vegetation, after which annual manipulations of soil resource availability (five levels of superphosphate fertilizer; the highest level was also irrigated) and disturbance (three 'mob-grazed' sheep grazing intensity levels: lax, moderate, hard) were applied. We used community assembly through trait selection (CATS) models based on entropy maximization to predict species relative abundances and to quantify the relative importance of each trait in determining abundance. 3. Plant species were primarily differentiated along a trade-off axis corresponding to traits promoting rapid growth (e.g. high leaf [N] and specific leaf area [SLA]) vs. those promoting long leaf life span. Using 12 traits, the CATS model predicted >80% of the variation in the relative abundances of 51 species, suggesting that trait-based filtering was important. 4. Species with leaf attributes that reduce nutrient losses held a long-term advantage under the lowest soil resource availability, whereas those associated with a rapid growth rate became dominant under soil resource addition. Species with thinner leaves were also favoured under greater soil resource availability, which may reflect a strategy to maximize SLA without sacrificing leaf density and thus maintain leaf structural defences under grazing disturbance. Greater leaf [S] and the ability to symbiotically fix atmospheric N were favoured under greater soil resource availability. Greater plant height, thinner leaves and higher leaf [N] were favoured under lower grazing intensity. 5. Synthesis. Our results highlight the importance of species functional differences to understand how plant communities react to increases in soil resource availability and disturbance, two important and inseparable components of land-use change in grasslands world-wide. [ABSTRACT FROM AUTHOR]

Lignins isolated from the annual grassy plants oats Avena sativa, rye Secale sp., wheat Triticum sp., and barley Hordeum sp. were characterized chemically. It was found that the grassy lignins belonged to a class of compositionally heterogeneous GSH-type biopolymers and consisted of monomeric units of the guaiacyl, syringyl, and p-coumaryl types. [ABSTRACT FROM AUTHOR]

1. Ungulate herbivores may greatly alter the functional composition of plant communities through their selection of leaves with high nutrient concentrations and low structural or chemical defences. These impacts may have broader implications for ecosystem functions via changing rates of litter decomposition and the relative abundance of foliar traits. However, it is unlikely that ungulate impacts will be consistent across different vegetation types and different environmental conditions. 2. We compared shifts in abundance-weighted trait means and functional diversity indices in 88 pairs of plots fenced to exclude ungulate herbivores (exclosures) and adjacent control plots for eight foliar traits related to ungulate palatability in forest ecosystems. The stem density and basal area per species were both used to weight trait means and functional diversity indices, since these are proportional to recruitment and litter production, respectively. We also regressed exclosure effects on environmental and stand development variables to test whether context influenced the impact of ungulate exclusion. 3. There was a consistent, significant trend across seven of the eight leaf traits examined for increased palatability inside exclosure plots relative to control plots when trait means were weighted by the number of stems per species, but not when weighted by basal area. This suggests that ungulate exclosure consistently increased recruitment of palatable species, but is unlikely to have yet affected mean litter quality. Exclosure effects were linked to stand development variables, with effects being greatest in disturbed stands (where total basal area decreased and the number of stems increased), and least in stands undergoing competitive thinning. 4. Synthesis. The consistency of exclosure effects indicates that ungulate impacts on plant communities in New Zealand's indigenous forest may be reversible at zero deer density, while their dependence on stand development suggests that the ungulate control impacts may be greatest in seral shrubland or forest communities. [ABSTRACT FROM AUTHOR]

Aim We test how productivity, disturbance rate, plant functional composition and species richness gradients control changes in the composition of high-latitude vegetation during recent climatic warming. Location Northern Fennoscandia, Europe. Methods We resampled tree line ecotone vegetation sites sampled 26 years earlier. To quantify compositional changes, we used generalized linear models to test relationships between compositional changes and environmental gradients. Results Compositional changes in species abundances are positively related to the normalized difference vegetation index (NDVI)-based estimate of productivity gradient and to geomorphological disturbance. Competitive species in fertile sites show the greatest changes in abundance, opposed to negligible changes in infertile sites. Change in species richness is negatively related to initial richness, whereas geomorphological disturbance has positive effects on change in richness. Few lowland species have moved towards higher elevations. Main conclusions The sensitivity of vegetation to climate change depends on a complex interplay between productivity, physical and biotic disturbances, plant functional composition and richness. Our results suggest that vegetation on productive sites, such as herb-rich deciduous forests at low altitudes, is more sensitive to climate warming than alpine tundra vegetation where grazing may have strong buffering effects. Geomorphological disturbance promotes vegetation change under climatic warming, whereas high diversity has a stabilizing effect. [ABSTRACT FROM AUTHOR]

A survey of 93 wetlands in six catchments across the Maloti-Drakensberg is used to assess the distribution of plant functional types across altitudinal and wetness gradients. Altitudes range from 1,000 to 3,200 m a.s.l. Within each catchment, the wetlands were selected to cover the complete range in altitude and wetland types. In each of the selected wetlands, vegetation was sampled in 3 by 3 m quadrats covering the entire range of wetness represented in the wetland, from temporarily wet to permanently inundated soils. Plant species were allocated to one of 11 different functional types (examples are C3 grasses, C4 sedges, rosette plants, and shrubs), and the proportion of the vegetation in each sample occupied by each functional type was calculated from the species’ abundances. Canonical Correspondence Analysis shows that “wetness” clearly has the highest impact on the distribution of functional types, followed by altitude. The most important plant functional types in wetlands are grasses and sedges, however, at higher altitudes, forbs (especially rosette plants) and bulbous plants become a more prominent feature in the wetlands. The total amount of graminoids gradually decreases with altitude. The general trend is that sedges tend to increase with increasing wetness and C3 plants (grasses and sedges) increase with increasing altitude, but these effects are not independent. The distributions of C4 sedges and C4 grasses along an altitudinal gradient are quite different, and C4 grasses grow abundantly at much higher altitudes than C4 sedges. C4 sedges are very scarce at the altitudes represented in the Maloti-Drakensberg area, whereas C3 grasses occur in the permanently wet parts of the wetlands, especially at higher altitudes (normally mostly occupied by sedges). Shrubs are rare in wetlands and tend to be an indication of disturbance. This study complements previous studies on the distribution of grasses and sedges at the lower altitudes within KwaZulu-Natal, which found that at altitudes below 1,000 m a.s.l. C4 sedges were much more prominent, while forbs and rosette plants were largely absent. This confirms that C4 as an adaptation to hotter and warmer climates is sometimes a less favorable metabolism in wet high altitude areas. At high altitudes, rosette plants and bulbous plants become more competitive in wetlands, probably because grasses and sedges present at these altitudes generally grow smaller than they do in low altitude wetlands. [ABSTRACT FROM AUTHOR]

A new framework for measuring functional diversity (FD) from multiple traits has recently been proposed. This framework was mostly limited to quantitative traits without missing values and to situations in which there are more species than traits, although the authors had suggested a way to extend their framework to other trait types. The main purpose of this note is to further develop this suggestion. We describe a highly flexible distance-based framework to measure different facets of FD in multidimensional trait space from any distance or dissimilarity measure, any number of traits, and from different trait types (i.e., quantitative, semi-quantitative, and qualitative). This new approach allows for missing trait values and the weighting of individual traits. We also present a new multidimensional FD index, called functional dispersion (FDis), which is closely related to Rao's quadratic entropy. FDis is the multivariate analogue of the weighted mean absolute deviation (MAD), in which the weights are species relative abundances. For unweighted presence-absence data, FDis can. be used for a formal statistical test of differences in FD. We provide the "FD" R language package to easily implement our distance-based FD framework. [ABSTRACT FROM AUTHOR]

Abstract: The relationship of functional diversity and composition was studied in gradients of organically enriched sediments from four Mediterranean fish farms. Within-functional trait diversity was also used to examine the functional redundancy of specific functional traits. Characteristics considered to respond to different geochemical conditions of the sediment were chosen for the traits list of that organism and were classified into ecological and morphological traits. Each trait was split up into several categories chosen to encompass the range of possible attributes of all species. The abundance of species possessing the same code was summed for each sample. Functional codes analyses differentiated between the sediment types and the TOC states, confirming the sensitivity of the functional characteristics to the geochemistry of the sediment. Changes in species number and abundance in the compared sites determined the shifts of the functional processes and not the presence or absence of individual traits. The important functional codes for the homogeneity within the examined habitats were fewer in the disturbed areas indicating that the functioning of these ecosystems is significantly reduced. [Copyright &y& Elsevier]

Abstract: Evolutionary conservation of neighbouring gene pairs has been widely explored in many species, but remains poorly understood in plants. The availability of several plant genome sequences allows for an in-depth investigation of this problem in plants. Here, we analyzed the phylogenetic conservation of physically linked gene pairs in nine plant genomes and compared the conservation in different orientations. We also examined several potential determinants to detect whether they affect the conservation of neighbouring gene pairs. Our results suggested that among the three types of neighbouring gene pairs, closely linked parallel pairs might be the least conserved. Intergenic distance was shown to be a major determinant of linkage conservation, suggesting that the conservation of gene order in plants was determined primarily by chance. The enrichment of housekeeping genes was identified to contribute to the conservation of all three types and the enrichment of genes involved in protein metabolism might contribute to the conservation of parallel pairs. Moreover, a co-expressed signal was detected in conserved divergent pairs, which might be determined by intergenic distance. [Copyright &y& Elsevier]

Structural transformations of potato starch by solutions of nitrogen(IV) oxide in CCl4 were studied as a function of oxidant concentration, starch moisture content, reaction time, and molar ratio of reactants. Oxidized starches with various numbers of carboxylic acids were studied by x-ray phase analysis, 13C NMR, and IR spectroscopy. It was found that carboxylic acids were formed primarily on C6 in starch oxidation products that were x-ray amorphous. The number of carboxyls increased slightly with increased oxidation time and oxidant concentration. It was shown that moisture must be present in the starch for oxidation by nitrogen(IV) oxide to be effective. [ABSTRACT FROM AUTHOR]

Structural transformations of potato starch by solutions of nitrogen(IV) oxide in CCl4 were studied as a function of oxidant concentration, starch moisture content, reaction time, and molar ratio of reactants. Oxidized starches with various numbers of carboxylic acids were studied by x-ray phase analysis, 13C NMR, and IR spectroscopy. It was found that carboxylic acids were formed primarily on C6 in starch oxidation products that were x-ray amorphous. The number of carboxyls increased slightly with increased oxidation time and oxidant concentration. It was shown that moisture must be present in the starch for oxidation by nitrogen(IV) oxide to be effective. [ABSTRACT FROM AUTHOR]

Abstract: I have used mathematica to solve several problems that relate to the symbolic calculation of the ‘molecular integrals’ that are a mainstay of computational chemistry. This work has provided many new results of chemical and mathematical interest, and it has led to a powerful programming methodology that I call mathscape that uses a novel open ended set of macros. Some further work on molecular integrals is presented here, largely as an introduction to mathscape. I discuss (1) the immediate mathematical problem of the ‘’ integrals, (2) the key features of mathscape, (3) a novel reduction of the integrals, (4) the chemical context of this work, and (5) the computer science context. [Copyright &y& Elsevier]

The content of reactive groups such as OH, CO, and COOH was increased by modifying hydrolyzed lignin with sulfuric acid and sodium hydroxide. The increase was confirmed by IR spectral analysis. The sorptive capacity of the resulting hydrolyzed lignin derivatives was increased sharply by base activation. [ABSTRACT FROM AUTHOR]

The extent to which complex interrelationships between plants and microorganisms influence organic matter dynamics is critical to our understanding of global C cycles in changing environments. We examined the hypothesis that patterns of soil microbial activity and functional composition differ among vegetation types in northern peatland ecosystems. Microbial characteristics were compared among peatlands differing in plant growth form (tree, shrub/moss, sedge) in two regions (New York State and West Virginia). Microbial activity (basal respiration) was greater in surface (0–15 cm) than subsurface (15–30 cm) peat and from sites dominated by shrubs and Sphagnum moss (3.9±0.65 μg C g−1 h−1) compared to forested (1.8±0.20 μg C g−1 h−1) or sedge-dominated sites (1.9±0.38 μg C g−1 h−1). Microbial activity was not related to decomposability of peat organic matter among vegetation types, and activity was unexpectedly higher in sites with lower peat pH and higher water table level. Substrate-induced respiration (SIR) did not show a clear pattern among vegetation types, but was greater in surface than subsurface peat. Microbial responsiveness to added glucose was very low. The ratio of basal respiration to SIR varied between 0.39 and 0.72 and, like activity, was highest in shrub/Sphagnum sites. Microbial substrate utilization patterns (assayed with BIOLOG® GN plates) also differed between shrub/Sphagnum sites and forest or sedge sites, suggesting that C fluxes were mediated by different assemblages of microorganisms in shrub/Sphagnum peatlands. Principal component (PC) scores indicated more utilization of N-containing compounds and carboxylic acids, and less utilization of carbohydrates by microbial communities in shrub/Sphagnum sites. PC scores were much more variable both within and among vegetation types for sites in West Virginia than in New York State, and a greater diversity of C sources were utilized in WV (57±3) than NYS (47±2) peat. Our results suggest a link between microbial respiratory activity and microbial functional composition as they vary among these peatland vegetation types. [Copyright &y& Elsevier]

Seagrass form high productive ecosystems in coastal environments. However, the effects of these coastal plants on the structure and function of the belowground eukaryotic microbiome remain elusive. In this study, we characterized the community of microbial eukaryotes (microeukaryotes) in both vegetated and unvegetated sediments using 18S rRNA gene amplicon sequencing and quantitative PCR. Analysis of sequencing data showed that the eelgrass ( Zostera marina ) colonization decreased the alpha diversity indices of benthic microeukaryotes. Apicomplexa represented an average of 83% of reads across all samples, with a higher proportion at the vegetated sites. The taxonomic community structure was significantly different between these two types of sediments, for which the concentration of NH 4 + in sediment porewater and salinity could account. Phylogenetic analyses of long 18S rRNA genes (around 1,030 bp) indicated these apicomplexan parasites are closely related to gregarine Lecudina polymorpha . Determination of 18S rRNA gene abundances provided evidence that the eelgrass markedly promoted the biomass of the gregarine and all microeukaryotes in the seagrass-colonized sediments and confirmed that the gregarine was hosted by a polychaete species. Significantly higher gene abundances of heterotrophs and mixotrophs were found at the vegetated sites, which could be explained by the finer sediments and short supply of dissolved inorganic nitrogen, respectively. The pigmented protists were more abundant in 18S rRNA gene copies at the lower and higher pH levels than at the intermediate. Nevertheless, the fractions of heterotrophs and phototrophs in the community were significantly related to porewater N:P ratio. These results indicate that seagrass colonization significantly induces an increase in overall biomass and a decrease in diversity of benthic microeukaryotes, making them more heterotrophic. This study also highlights that the hotspot of eukaryotic parasites could be linked with the high productivity of a natural ecosystem., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Pan, Li, Su, Zheng, Wang, Shen, Chen, Han and Gong.)

Grazing is a substantial threat to the sustainability of grassland ecosystems, while it is uncertain about the variety of plant and soil microbial community and the linkages between them limit the comprehensive understanding of grazing ecology. We conducted an experiment on the effects of the grazing regimes rotational grazing (RG), continuous grazing (CG), and grazing exclusion (GE) on an alpine meadow in Qinghai-Tibetan Plateau. The differences of plant community composition, soil microbial community assembly mechanism, and taxonomic and functional composition between grazing regimes were examined, and the relationship between plant species and the soil microbes was assessed by constructing a co-occurrence network. The results showed that the plant community composition varied with the grazing regimes, while the soil microbial community composition did not vary with the grazing regimes. The soil bacterial functional composition was similar under RG and CG, while the soil fungal functional composition was similar under GE and RG. The soil microbial community under all grazing regimes was assembled mainly according to stochastic rather than deterministic mechanisms, and RG and CG reduced the relative importance of the stochastic ratio. At the microbial phylum level, CG and GE increased the relative abundance of Acidobacteria and Armatimonadetes and CG and RG increased the relative abundance of Elusimicrobia. In the network of plant species and soil microbial classes, plants and bacteria themselves were mainly positively linked (symbiosis and promotion), while plants and soil microbes were mainly negatively linked (competition). There were five microbial generalists in the network, which connected with many microbes, and four showed no difference in their abundance among the grazing regimes. Overall, the stable key microbes in the network and the fact that many of the plants are unconnected with microbes weakened the impact of grazing-induced changes in the plant community on soil microbes, probably resulting in the stable soil microbial community composition. Moreover, there was still a dominant and tolerant plant species, Kobresia pygmaea , that connected the plant and microbial communities, implying that the dominant plant species not only played a crucial role in the plant community but also acted as a bridge between the plants and soil microbes; thus, its tolerance and dominance might stabilize the soil microbial community., Competing Interests: YY was employed by China New Era Group Corporation. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Li, Dong, Gao, Fan, Fayiah, Ganjurjav, Hu, Wang, Yan, Gao and Li.)

Background: Disturbances are crucial in determining forest biodiversity, dynamics, and ecosystem functions. Surface fire is a significant disturbance in tropical forests, but research on the effect of surface fire on structuring species and functional composition in a community through time remains scarce. Using a 20-year dataset of tree demography in a seasonal evergreen tropical forest in Thailand, we specifically addressed two essential questions: (1) What is the pattern of temporal turnover in species and functional composition in a community with frequent fire disturbance? (2) How did the temporal turnover vary with tree size?, Methods: We analyzed species compositional and functional temporal turnovers in four different tree size classes among five tree censuses. We quantified species turnover by calculating Bray-Curtis dissimilarity, and investigated its underlying mechanisms by comparing pairwise dissimilarity of functional traits with simulations from null models. If fire disturbances contribute more to a stochastic process, the functional composition would display a random pattern. However, if they contribute more towards a deterministic process, the functional composition should reveal a non-random pattern., Results: Over 20 years (1994-2014), we observed changes in species composition, whereas functional composition remained relatively stable. The temporal turnover patterns of species and functional compositions varied with tree sizes. In particular, temporal functional turnover shifted very little for large trees, suggesting that changes in species composition of larger trees are contributed by species with similar functional traits through time. The temporal functional composition turnovers of smaller trees (DBH ≤ 5 cm) were mostly at random. We detected a higher functional turnover than expected by null models in some quadrats throughout the 50-ha study plot, and their observed turnover varied with diameter classes., Conclusions: Species compositional changes were caused by changes in the abundance of species with similar functional traits through time. Temporal functional turnover in small trees was random in most quadrats, suggesting that the recruits came from the equal proportions of surviving trees and new individuals of fast-growing species, which increased rapidly after fires. On the other hand, functional composition in big trees was more likely determined by surviving trees which maintained higher functional similarities than small trees through time. Fire disturbance is important for ecosystem functions, as changing forest fire frequency may alter forest turnover, particularly in functional composition in the new recruits of this forest., Competing Interests: The authors declare that they have no competing interests., (© 2022 Kaewsong et al.)

Increased nitrogen (N) deposition may have profound effects on forest ecosystems. However, information on the impacts of elevated N deposition on belowground soil seed bank in forests is lacking. In a field experiment, we added N at 50 and 25 kg N ha−1 year−1 to the canopy (CAN50 and CAN25) and to the understory (UAN50 and UAN25), to determine the effects of N deposition on soil seed bank structure and composition in a subtropical evergreen broadleaved forest. A total of 1545 seedlings belonging to 37 species emerged from the 10 cm-depth soil samples. After 6 years of N addition, soil seed bank density significantly increased at the depth of 0–10 cm under CAN50 treatment relative to the control. N addition did not significantly affect species richness, the Simpson index, Shannon–Wiener index, or Pielou index of the soil seed banks. Seed bank density and species richness were positively correlated with soil organic matter content. For the whole 0–10 cm soil layer, the percentage of total seed abundance and total species richness represented by tree species among the N-addition treatments was ≤9.3% and ≤16.1%, respectively. Soil seed bank composition was similar among UAN25, UAN50, and the control, but canopy N addition and especially CAN50 altered the species composition of the seed bank. Overall, our results indicate that artificial canopy N deposition at 50 kg N ha−1 year−1 but not understory N addition tends to promote seed storage and to change species composition in the soil seed bank. Because of the dominance of shrubs and herbs in the soil seed bank, the potential to regenerate tree species from the soil seed bank is limited in the subtropical evergreen broadleaved forest. [ABSTRACT FROM AUTHOR]

Forests play a key role in regulating the global carbon cycle, a substantial portion of which is stored in aboveground biomass (AGB). It is well understood that biodiversity can increase the biomass through complementarity and mass-ratio effects, and the contribution of environmental factors and stand structure attributes to AGB was also observed. However, the relative influence of these factors in determining the AGB of Quercus forests remains poorly understood. Using a large dataset retrieved from 523 permanent forest inventory plots across Northeast China, we examined the effects of integrated multiple tree species diversity components (i.e., species richness, functional, and phylogenetic diversity), functional traits composition, environmental factors (climate and soil), stand age, and structure attributes (stand density, tree size diversity) on AGB based on structural equation models. We found that species richness and phylogenetic diversity both were not correlated with AGB. However, functional diversity positively affected AGB via an indirect effect in line with the complementarity effect. Moreover, the community-weighted mean of specific leaf area and height increased AGB directly and indirectly, respectively; demonstrating the mass-ratio effect. Furthermore, stand age, density, and tree size diversity were more important modulators of AGB than biodiversity. Our study highlights that biodiversity-AGB interaction is dependent on the regulation of stand structure that can be even more important for maintaining high biomass than biodiversity in temperate Quercus forests., (© 2021 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)