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Ecosystems worldwide are experiencing a range of natural and anthropogenic disturbances, many of which are intensifying as global change accelerates. Ecological responses to those disturbances are determined by both the vulnerabilities of species and their interspecific interactions. Understanding how individual species contribute to the (in‐)stability of an aggregated community property, or function, is fundamental to ecological management and conservation. Here, we present a framework to identify species contributions to stability based on their absolute and relative responses to disturbances. Using simulations, we show that these two dimensions enable identification of (de‐)stabilizing species and reveal that competitive dominance determines the magnitude of both absolute and relative contributions to stability. Applying our framework to empirical data from a multi‐site mesocosm experiment showed that species contributions varied among treatments, sites, and seasons. Despite this dependency on both biotic and abiotic contexts, species contributions were generally constrained by their relative dominance in undisturbed conditions. Rare species contributed positively to stability, while dominant species contributed negatively, indicating compensatory dynamics. Our framework offers an important step toward a more mechanistic understanding of ecological stability based on species performance. [ABSTRACT FROM AUTHOR]

Due of the potential of species to determine ecosystem properties, it is important to understand how species abundance influences community assembly. Using vegetation surveys on 35 dry grasslands in north-east Slovenia, we defined dominant (8) and subordinate (61) plant species. They were compared on 14 traits to test for differences in community-weighted mean (CWM) and functional diversity (FD). We found that dominants and subordinates differed strongly in their functional traits. Dominants showed higher leaf dry matter content and a more pronounced stress tolerance strategy and were all clonal with a large proportion of species with rhizomes and a rich bud bank, while other species showed a higher specific leaf area, a longer flowering period and more ruderals. For most traits, FD was higher in subordinates. Our results suggest that dominants drive community structure by limited susceptibility to non-competitive processes. Dominants may have positive effects on subordinates by mitigating environmental stressors. Subordinates are able to assemble together by being dissimilar and use different fine-scale niches that are engineered and homogenised by dominants. Our results show that there are fundamental differences in the relative importance of ecological processes between dominant and subordinate plants in species-rich grasslands, which is also important for their conservational management. [ABSTRACT FROM AUTHOR]

One of the most important functions of forests is their capacity to store carbon, which varies according to floristic composition, age, and tree density. To provide information that is useful for the carbon inventories, the construction of growth curves for dominant strata within the study area was set as the objective of this work. With data from the National Forest and Soil Inventory 2005-2009 were calculated the IVI by conglomerate and from a dendrogram performed with cluster analysis, using the Ward's linkage method, dominant strata were formed. A growth curve per community was constructed based on the maximum yields per hectare recorded in the forestry management plans, the percentage increases were attributed to volume per species at different ages, which was obtained by ICA through trunk analysis. Five dominant strata were formed; Pinus oocarpa (21.08 % to 54.38 %), Pinus douglasiana (41.45 % to 89.83 %), Pinus devoniana (27.53 % to 63.88 %), Pinus leiophylla (27.53 % to 89.03 %) and Quercus spp. (36.05 % to 93.26 %). The maximum yields for the stands within the study area were 329.98 m3 ha-1, 330.71 m3 ha-1, 171.35 m3 ha-1, 185.22 % and 127. 46 m3 ha-1, respectively. The Pinus oocarpa and Pinus douglasiana dominant strata are had the highest percentage increases in the region due to their historical foment. [ABSTRACT FROM AUTHOR]

Feeding activities by fishes are among the key ecological processes that sustain coral reef functioning. Those trophic-based processes are known to vary across space and across seasons or years. However, there is still little knowledge about their variability within and between days as well as whether these processes are dominated by the same species across time. Using remote underwater cameras, we quantified rates of three feeding activities (corallivory, herbivory and invertivory) for three one-hour time slots (morning, midday, afternoon) over two days on two coral reefs around Mayotte Island (Western Indian Ocean). Feeding activities were highly variable at within and between-day scales and concentrated in a few pulses. Herbivory was the highest in the afternoon which aligns with previous findings regarding activity of herbivorous fishes. Corallivory was the highest in the morning, which highlights the advantage of long-duration benthic remote underwater videos to accurately assess all trophic activities. Trophic-related processes were dominated by the same few species in both sites and across time of the day. This study pinpoints the importance of including within-day and between-day variations when studying ecological processes, as neglecting these variations may introduce biases into our understanding of these processes. [ABSTRACT FROM AUTHOR]

Due of the potential of species to determine ecosystem properties, it is important to understand how species abundance influences community assembly. Using vegetation surveys on 35 dry grasslands in north-east Slovenia, we defined dominant (8) and subordinate (61) plant species. They were compared on 14 traits to test for differences in community-weighted mean (CWM) and functional diversity (FD). We found that dominants and subordinates differed strongly in their functional traits. Dominants showed higher leaf dry matter content and a more pronounced stress tolerance strategy and were all clonal with a large proportion of species with rhizomes and a rich bud bank, while other species showed a higher specific leaf area, a longer flowering period and more ruderals. For most traits, FD was higher in subordinates. Our results suggest that dominants drive community structure by limited susceptibility to non-competitive processes. Dominants may have positive effects on subordinates by mitigating environmental stressors. Subordinates are able to assemble together by being dissimilar and use different fine-scale niches that are engineered and homogenised by dominants. Our results show that there are fundamental differences in the relative importance of ecological processes between dominant and subordinate plants in species-rich grasslands, which is also important for their conservational management.

Leaf traits can reflect plant photosynthetic capacity, resource utilization strategy and adaptability to the environment. However, whether species' leaf traits are tightly related to the functioning of their community and how that relationship varies with environmental gradients remain largely unexplored. We measured 6 leaf traits, including petiole fineness (PF), specific leaf area (SLA), leaf area (LA), leaf length–width ratio (LLWR), leaf nitrogen content (LN) and leaf phosphorus content (LP), of 733 populations (415 species) of 19 woody angiosperm communities in the eastern Qinghai–Tibetan Plateau across multiple climatic zones or vegetation types. Through meta-analysis and relative importance analysis, the relationship between leaf traits of species and their community dominance and its change with environments were analyzed. The results showed that species dominance was correlated positively with their LA and LP, suggesting that species with high light interception and resource utilization capacity can easily become dominant species in woody angiosperm communities. Along the altitudinal gradient, the effect of PF and SLA on species dominance increased and changed significantly in their pattern, from positive or nonsignificant in temperate forests to negative in alpine and subalpine shrubs, suggesting that increasing petiole mechanical support and lamina protection cost is a dominant leaf growth strategy in stressful high-altitude environments. Our findings demonstrate that the demand for efficient light acquisition and/or utilization and species adaptability or tolerance to specific environmental stress are key mechanisms by which leaf traits govern community composition and functioning. [ABSTRACT FROM AUTHOR]

During the observation period (April 2019-March 2020), 36 species of insects were recorded belonging to 29 families from all the selected study sites. The maximum species were recorded in order Lepidoptera followed by Hemiptera. A minimum of one species was recorded from each order, Dictyoptera, Isoptera, Neuroptera, and Diptera, from three selected sugarcane agriculture field sites. The maximum number of individuals was collected from Site I, followed by Site II, whereas the lowest number of individuals was recorded at Site III. The observation showed that seasonal abundance had two peaks, first during the summer months of June and second during the spring season of March. The study of insect diversity represents species richness as highest at Site I (based on species number and Shannon index). In contrast, species dominance was maximum at Site II (Simpson index and Berger Parker) due to over dominance of one species. The Evenness index showed maximum evenness of species at Site I. [ABSTRACT FROM AUTHOR]

Simple Summary: In this article, we studied the interactions between the invasive thrips pest Frankliniella occidentalis (WFT) and a native thrips Frankliniella intonsa (IFT) in China, where they co-exist on crop plants and WFT seems to outcompete IFT. In laboratory bioassays we focused on the reproductive mode of the thrips (sexual or parthenogenic), and the presence of a sugar source (honey or flowers), both variables that change over time during pest colonisation of a crop. Our results suggest that in the early stages of F. occidentalis invasion, the provision of honey (flowering) promotes this pest's population development. This research will inform effective strategies for the management of F. occidentalis invasion and help reduce subsequent crop damages. Background: Flower thrips (Frankliniella intonsa, IFT) and west flower thrips (Frankliniella occidentalis, WFT) are often found together on the host plant in China. WFT is an important invasive species that seems to outcompete the native IFT. In order to clarify the interspecific competitions between the two thrips, this study measured the population development of IFT and WFT under sexual and parthenogenetic reproductive modes on two hosts (fresh lentil bean pods with/without honey and pepper plants at seedling/flowering stages) in the laboratory. Results: When reared on fresh lentil bean pods (with/without honey), WFT population size was lower in mixed species populations compared to single species populations but the presence of WFT had nor negative effect on IFT population size. These results were dependent of the reproductive mode. When honey was supplied, the ratio of female-to-male in the progeny of WFT produced under sexual reproductive mode increased significantly in the presence of IFT. On pepper seedlings, mixed populations were more favorable to the population development of IFT at the seedling stage, but more favorable to WFT at the flowering stage. Conclusions: In the early stage of WFT invasion and colonization, the emergence of flowering and honey (nectar) sources may have a positive effect on the population development of WFT. [ABSTRACT FROM AUTHOR]

The quantification of vegetation structure and composition at local and global scales provides valuable information for understanding the balance of the natural and human-made environment, which is crucial for natural resource planning and management, and the sustenance of ecosystem biodiversity. In this study, we proposed using the Sentinel 2A imagery to classify vegetation cover into communities based on the floristic association of individual vegetation species. We apply traditional remote sensing techniques to process the satellite image and identify training regions of interest (ROI) which are thoroughly assessed for spectral uniqueness before using the pixel-based supervised classification algorithms for our classification. Ground truthing assessment and species dominance computations are done to determine the vegetation community composition and naming based on floristic associations. We apply the floristic compositions output in analysing elephant movement tracks in the area, to assess the potential influence the location of specific vegetation species and communities utilized by elephants has on their movement and presence, as well as on elephant bulls and family groupings. The results show that the 10 m spatial resolution Sentinel-2A is suitable for investigating and mapping vegetation species in communities for large-scale mapping operations. We determined Near-Infrared band 8 and shortwave Infrared band 11 as key for identifying and differentiating ROIs at the floristic association community vegetation mapping level. We attained an overall accuracy of 87.395%. The analysis proved the 10 m spatial resolution of Sentinel 2A to be sufficient in distinguishing vegetation communities, including those with similar dominant species but variations in other contributing species. We also found a direct connection between vegetation location and elephant movement based on the summative analysis of utilised vegetation by the different elephant groupings. Bull elephants were predominantly present in areas with Combretum, family groups in areas with Commiphora, and mixed groups with both bulls and families in areas with Commiphora, and Cissus. This study shows the value that remote-sensing scientific support can offer conservationists and governments in objective evidence-based land management, policy making and governance. [ABSTRACT FROM AUTHOR]

Vitis vinifera L. ssp. sylvestris (Gmelin) Hegi is recognized as the dioecious parental generation of today's cultivars. Climatic change and the arrival of pathogens and pests in Europe led it to be included on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species in 1997. The present work focused on the study of culturable yeast occurrence and diversity of grape berries collected from wild vines. Sampling was performed in 29 locations of Azerbaijan, Georgia, Italy, Romania, and Spain. In total, 3431 yeast colonies were isolated and identified as belonging to 49 species, including Saccharomyces cerevisiae, by 26S rDNA D1/D2 domains and ITS region sequencing. Isolates of S. cerevisiae were also analyzed by SSR–PCR obtaining 185 different genotypes. Classical ecology indices were used to obtain the richness (S), the biodiversity (H'), and the dominance (D) of the species studied. This study highlights the biodiversity potential of natural environments that still represent a fascinating source of solutions to common problems in winemaking. [ABSTRACT FROM AUTHOR]

Forests in Northeast China in the Greater and Lesser Khingan Mountains (GKM and LKM) account for nearly 1/3 of the total state-owned forests in the country. Regional and historical comparisons of forest plants and macrofungi will favor biological conservation, forest management and economic development. A total of 1067 sampling plots were surveyed on forest composition and structure, with a macrofungi survey at Liangshui and Huzhong Nature Reserves in the center of two regions. Regional and historical differences of these parameters were analyzed with a redundancy ordination of their complex associations. There were 61–76 families, 189–196 genera, and 369–384 species, which was only 1/3 of the historical records. The same dominant species were larch and birch with Korean pine (a climax species) less as expected from past surveys in the LKM. Shrub and herb species were different in the two regions, as expected from historical records. There was 10–50% lower species diversity (except for herb evenness), but 1.8- to 4-time higher macrofungi diversity in the GKM. Compared with the LKM, both tree heights and macrofungi density were higher. Nevertheless, current heights averaging 10 m are half of historical records (> 20 m in the 1960s). Edible macrofungi were the highest proportion in both regions, about twice that of other fungal groups, having important roles in the local economy. A major factor explaining plant diversity variations in both regions was herb cover, followed by shrubs in the GKM and herb-dominant species in the LKM. Factors responsible for macrofungi variations were tree density and shrub height. Vaccinium vitis-idaea and Larix gmelinii in the GKM but tree size and diversity were important factors in the LKM. Our findings highlighted large spatial and historical differences between the GKM and LKM in plant-macrofungal composition, forest structure, and their complex associations, which will favor precise conservation and management of forest resources in two region in the future. [ABSTRACT FROM AUTHOR]

Aim: Climate warming and biodiversity loss both alter plant productivity, yet we lack an understanding of how biodiversity regulates the responses of ecosystems to warming. In this study, we examine how plant diversity regulates the responses of grassland productivity to experimental warming using meta‐analytic techniques. Location: Global. Major taxa studied: Grassland ecosystems. Methods: Our meta‐analysis is based on warming responses of 40 different plant communities obtained from 20 independent studies on grasslands across five continents. Results: Our results show that plant diversity and its responses to warming were the most important factors regulating the warming effects on plant productivity, among all the factors considered (plant diversity, climate and experimental settings). Specifically, warming increased plant productivity when plant diversity (indicated by effective number of species) in grasslands was lower than 10, whereas warming decreased plant productivity when plant diversity was greater than 10. Moreover, the structural equation modelling showed that the magnitude of warming enhanced plant productivity by increasing the performance of dominant plant species in grasslands of diversity lower than 10. The negative effects of warming on productivity in grasslands with plant diversity greater than 10 were partly explained by diversity‐induced decline in plant dominance. Main conclusions: Our findings suggest that the positive or negative effect of warming on grassland productivity depends on how biodiverse a grassland is. This may mainly be due to differences in how warming may affect plant dominance and subsequent shifts in interspecific interactions in grasslands of different plant diversity levels. [ABSTRACT FROM AUTHOR]

Biotic and abiotic factors interact with dominant plants—the locally most frequent or with the largest coverage—and nondominant plants differently, partially because dominant plants modify the environment where nondominant plants grow. For instance, if dominant plants compete strongly, they will deplete most resources, forcing nondominant plants into a narrower niche space. Conversely, if dominant plants are constrained by the environment, they might not exhaust available resources but instead may ameliorate environmental stressors that usually limit nondominants. Hence, the nature of interactions among nondominant species could be modified by dominant species. Furthermore, these differences could translate into a disparity in the phylogenetic relatedness among dominants compared to the relatedness among nondominants. By estimating phylogenetic dispersion in 78 grasslands across five continents, we found that dominant species were clustered (e.g., co‐dominant grasses), suggesting dominant species are likely organized by environmental filtering, and that nondominant species were either randomly assembled or overdispersed. Traits showed similar trends for those sites (<50%) with sufficient trait data. Furthermore, several lineages scattered in the phylogeny had more nondominant species than expected at random, suggesting that traits common in nondominants are phylogenetically conserved and have evolved multiple times. We also explored environmental drivers of the dominant/nondominant disparity. We found different assembly patterns for dominants and nondominants, consistent with asymmetries in assembly mechanisms. Among the different postulated mechanisms, our results suggest two complementary hypotheses seldom explored: (1) Nondominant species include lineages adapted to thrive in the environment generated by dominant species. (2) Even when dominant species reduce resources to nondominant ones, dominant species could have a stronger positive effect on some nondominants by ameliorating environmental stressors affecting them, than by depleting resources and increasing the environmental stress to those nondominants. These results show that the dominant/nondominant asymmetry has ecological and evolutionary consequences fundamental to understand plant communities. [ABSTRACT FROM AUTHOR]

Background: Increasing nitrogen (N) deposition has altered plant communities globally, however the changes in species abundances with short-term vs. long-term N enrichment remains unclear. Stoichiometric homeostasis, quantified by the homoeostatic regulation coefficient (H) is a key trait predictive of plant species dominance and species responses to short-term global changes. It is unknown whether H changes with N enrichment over time, thereby affecting species responses to long-term N addition. Methods: Here we investigated three representative plant species how species dominance changed to short-term and long-term N addition with a field N addition experiment (2006–2013) in an Inner Mongolia grassland. Changes in species H with long-term N addition were analyzed using a sand culture experiment, and the correlation between species H and species abundances were explored to address the above research gaps. Results: The abundance of Leymus chinensis decreased with short-term N addition, and increased with long-term N addition, while Chenopodium glaucum exhibited the opposite pattern. Cleistogenes squarrosa was only favored by 1-year N addition, and depressed by two or more years of N addition. The H values of L. chinensis and C. glaucum decreased significantly with long-term N addition, but did not change for C. squarrosa. The H values were significantly related with the abundance both in Control and long-term N addition treatments. Conclusion: Species abundance had opposite responses to short-term vs. long-term N addition. The decrease of H suggested the nutrients use strategy became more progressive, which mediated the responses of species abundances to short- and long-term N addition. [ABSTRACT FROM AUTHOR]

It was hypothesized that multiple environmental factors influence distribution and abundance of plant species in different vegetation layers of the forest ecosystem=. Here, we have assessed plant diversity, abundance and its relationship with multiple factors through an integrative modeling approach. To substantiate or negate our hypothesis, Quadrat quantitative ecological methods were carried out for the sampling of vegetation in Humid Forest Ecosystem of the Western Himalayas. Rectangular plots of 100 m, 50 m and 1 m were established for trees, shrubs and herb species, respectively. All the edaphic, topographic, climatic and disturbance factors were determined using different standard procedures and protocols. We have applied multiple linear regression and structural equation models using R-Software on most abundant plant species each from trees, shrubs and herbs. Preliminary, integrative modeling showed that the species abundance is significantly associated with a set of soil nutrients (physio-chemical variables), topography (aspect, slope, elevation) and disturbance factors (anthropogenic and grazing pressure). The species dominance effects were synchronously influenced (p˂0.025) by the soil physical characters (sand, silt and clay), canopy and regeneration potentials compared to other factors. Our results provide bases to understand the underlying mechanisms of species abundance and its importance of the forest ecosystem in the western Himalayas. This work concludes that ecological diversity is overall the result of multiple factors but climatic, topographic, anthropogenic and grazing pressures primarily shape the diversity and functioning in a forest ecosystem. Additionally, we found a clear pattern that variations in edaphic factors cause the abundance of certain species over others.

• Submerged macrophytes exhibited phosphorus stoichiometric homeostasis (H P). • H P value dictated submerged macrophyte community stability. • Eutrophication altered interspecific interactions among submerged macrophytes. • Decline of high- H P species reduced community stability. According to stoichiometric homeostasis theory, eutrophication is expected to increase the dominance of submerged macrophytes with low homeostatic regulation coefficients (H) relative to those with high H values, ultimately reducing macrophyte community stability. However, empirical evidence supporting this hypothesis is limited. In this study, we conducted a three-year tracking survey (seven sampling events) at 81 locations across three regions of Erhai Lake. We assessed the H values of submerged macrophyte species, revealing significant H values for phosphorus (P) and strong associations of H P values (range: 1.58–2.94) with species and community stability. Moreover, in plots simultaneously containing the dominant high- H P species, Potamogeton maackianus , and its low- H P counterpart, Ceratophyllum demersum , we explored the relationships among eutrophication, interspecific interaction shifts, and community dynamics. As the environmental P concentration increased, the dominance of P. maackianus decreased, while that of C. demersum increased. This shift coincided with reductions in community H P and stability. Our study underpins the effectiveness of H values for forecasting interspecific interactions among submerged macrophytes, thereby clarifying how eutrophication contributes to the decline in stability of the submerged macrophyte community. [Display omitted] [ABSTRACT FROM AUTHOR]

Background and Aims: Changing precipitation regimes can influence terrestrial plants and ecosystems. However, plant phenological responses to changing precipitation temporal patterns and the underlying mechanisms are largely unclear. This study was conducted to explore the effects of seasonal precipitation redistribution on plant reproductive phenology in a temperate steppe., Methods: A field experiment with control (C), advanced (AP) and delayed (DP) growing-season precipitation peaks, and the combination of AP and DP (ADP) were employed. Seven dominant plant species were selected and divided into two functional groups (early- vs. middle-flowering species, shallow- vs. deep-rooted species) to monitor reproductive phenology including budding, flowering, and fruiting date, as well as reproductive duration for four growing seasons from 2015 to 2017, and 2022., Key Results: The AP, but not DP treatment advanced the phenological (i.e., budding, flowering, and fruiting) dates and lengthened the reproductive duration across the 4 growing seasons and 7 monitored species. In addition, the phenological responses showed divergent patterns among different plant functional groups, which could be attributed to shifts in soil moisture and its variability in different months and soil depths. Moreover, species with lengthened reproductive duration increased phenological overlap with other species, which could have a negative impact on their dominance under the AP treatment., Conclusions: Our findings reveal that changing precipitation seasonality could have considerable impacts on plant phenology by affecting soil water availability and variability. Incorporating these two factors simultaneously in the phenology models will help us understand the response of plant phenology under intensified changing precipitation scenarios. In addition, the observations of decreased dominance for the species with lengthened reproductive duration suggest that changing reproductive phenology can have a potential to affect community composition in grasslands under global change., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Elements are important functional traits reflecting plant response to climate change. Multiple elements work jointly in plant physiology. Although a large number of studies have focused on the variation and allocation of multiple elements in plants, it remains unclear how these elements co-vary to adapt to environmental change. We proposed a novel concept of the multi-element network including the mutual effects between element concentrations to more effectively explore the alterations in response to long-term nitrogen (N) deposition. Leaf multi-element networks were constructed with 18 elements (i.e., six macronutrients, six micronutrients, and six trace elements) in this study. Multi-element networks were species-specific, being effectively discriminated irrespective of N deposition level. Different sensitive elements and interactions to N addition were found in different species, mainly concentrating on N, Ca, Mg, Mn, Li, Sr, Ba, and their related stoichiometry. Interestingly, high plasticity of multi-element network increased or maintained relative aboveground biomass (species dominance) in community under simulated N deposition, which developed the multi-element network hypothesis. In summary, multi-element networks provide a novel approach for exploring the adaptation strategies of plants and to better predict the change of species dominance under altering nutrient availability or environmental stress associated with future global climate change.

Studies of stoichiometric homeostasis in different types of plant species growing in alpine steppe environments are important in understanding the fitness and nutrient-use strategies of alpine plants in northern Tibet, which may be correlated with species dominance and stability. We used an N- and P-addition experiment to investigate the stoichiometric homeostasis N (HN) in the foliage of different plant species in the Stipa purpurea steppe of the Tibetan Plateau from 2013 to 2016. The concentration of N in the foliage of different types of plants increased significantly with the amount of N added. We found that the HN value of the foliage of alpine steppe plants was much lower than that of plants in temperate grasslands and grasslands with tall grass, suggesting that these alpine plants can absorb more nutrients when they are available. There was no difference in the HN values for different alpine plant species, which is also different from previously reported results for other types of grasslands. Furthermore, the temporal stability and dominance of species was not significantly correlated with the foliage HN value of the species. Our results suggest that the HN value of plant foliage in an alpine steppe environment little affected the species dominance and stability seen in the control and N-addition plots at the species level, which is in conflict with the results from temperate grasslands. The different types of species in this alpine steppe environment show the same nutrient utilization strategies (low HN value, about 2) for coping with a variable and limited supply of nutrients.

Elements are important functional traits reflecting plant response to climate change. Multiple elements work jointly in plant physiology. Although a large number of studies have focused on the variation and allocation of multiple elements in plants, it remains unclear how these elements co-vary to adapt to environmental change. We proposed a novel concept of the multi-element network including the mutual effects between element concentrations to more effectively explore the alterations in response to long-term nitrogen (N) deposition. Leaf multi-element networks were constructed with 18 elements (i.e., six macronutrients, six micronutrients, and six trace elements) in this study. Multi-element networks were species-specific, being effectively discriminated irrespective of N deposition level. Different sensitive elements and interactions to N addition were found in different species, mainly concentrating on N, Ca, Mg, Mn, Li, Sr, Ba, and their related stoichiometry. Interestingly, high plasticity of multi-element network increased or maintained relative aboveground biomass (species dominance) in community under simulated N deposition, which developed the multi-element network hypothesis. In summary, multi-element networks provide a novel approach for exploring the adaptation strategies of plants and to better predict the change of species dominance under altering nutrient availability or environmental stress associated with future global climate change. [ABSTRACT FROM AUTHOR]

An investigation on the structural characteristics of the riparian forest in Omo Biosphere Reserve was carried out. The structure was analyzed through diameter class distribution, basal area and breast height. Riparian forest showed a major characteristic in the physiognomy of forests along major river, streams and Upland vegetation and the Core, Buffer and Transition zones that is highly variable in the diameter class distribution (reserve J type), Mean basal area per hectare for major river is 294,089.30 cm²/ha, Stream 613.027 cm²/ha, and Upland 205,648 cm³/ha. Mean basal area for core is 507,399.50 cm2 /ha, buffer had 340,699 cm²/ha and transition 264,656 cm²/ha. While mean volume per hectare for core is 7955.2 m³/ha, buffer 7260 m³/ha and Transition 6254.4 m³/ha. Maximum dbh of 246 cm was obtained in the core species. Many stands of riparian forests are facing various levels of structural and floristic simplification, which include fundamental transformations in vegetation physiognomy from dense stands to riparian scrub or bare land. [ABSTRACT FROM AUTHOR]

Algal bioremediation can significantly improve the quality of wastewater by assimilating nutrients. However, the efficiency and stability of this approach depends on identifying suitable algae based on their biomass productivity and ability to outcompete less desirable algae. Here, we compare the productivity and competitive ability of three taxa of filamentous macroalgae under the seasonal light and temperature conditions experienced in temperate environments, including extremes of heat and cold. Specific growth rate was greatest for the tropical isolate of Oedogonium under summer conditions (36–40%; P < 0.05); however, it had lower growth under cooler (autumn, winter) conditions than the temperate algae of Stigeoclonium and Hyalotheca. Overall, Stigeoclonium and Hyalotheca had the most stable production across all treatments. A 5-week competition experiment found that each algae grew fastest in monoculture compared with bi-culture and poly-culture treatments. While all three genera showed a considerable level of competitive dominance depending on algae composition and environmental conditions, no single genus outperformed all others under all conditions. Oedogonium was dominant in warmer conditions, Stigeoclonium in cooler conditions (> 90% for both) and, in its absence, Hyalotheca also dominate over Oedogonium. Our results suggest that rather than finding an optimal taxon for all four seasons, the best decision for maximising stable biomass production will require either seasonal rotation of algae, or bi-cultures of the most dominant ones. Further, prioritising competition over production when selecting freshwater algae for wastewater bioremediation is likely to prove the most successful strategy. [ABSTRACT FROM AUTHOR]

We review literature relevant to assessing the future of tropical forests and supplement the review with new data from the lowlands of Venezuela. Compared to today, future tropical forests will have a higher level of novelty, defined as the degree of dissimilarity of a system relative to a historical baseline. Processes of succession and evolution generate novelty in forests and have done so for millennia. Under increasing human activity and climate change, the rate of generation of novelty has increased and the resulting forests are termed novel forests to distinguish them from historical forests. Historical forests are less exposed to anthropogenic disturbances and operate at slower levels of novelty generation. Acclimation, adaptation, changes in species composition and dominance, and changes in the proportions of species in communities are the responses of the biota to climate change and anthropogenic disturbances. Therefore, novelty contributes to the persistence of tropical forests in spite of increasing levels of human activity. Novel forests are similar to historical forests in terms of structure but they are younger, they have a faster turnover of mass and chemical elements, and different species composition. Historical species assemblages cannot cope with the altered environments that result from chronic anthropogenic disturbances. The dominant species in novel forests tend to be, and function as, pioneer species. High levels of species dominance in novel forests influence the proportions of chemical elements, which when coupled to species traits and attributes, help explain how novel forests cope with the conditions that result from anthropogenic activities. Novelty is more common in the tropics than in other latitudinal regions, and within the tropics, it is more common in islands where human activity is more intense than in continents. Novel tropical forests in islands have greater representation and dominance of introduced species than novel forests in continents, where native species with wide geographic distributions dominate. Regardless of geography, novel tropical forests share similar attributes and functioning. The adaptability of novel forests to extreme conditions created by human activity signals a future for tropical forests that is different from predictions of constant degradation, homogenization, and loss of biodiversity. Instead, a process of recombination of species (all taxa) into new species assemblages maintains structure, function, physiognomy, species richness, and ecological services. This remixing initially involves loss of large organisms, certain groups of species, and loss of old-growth attributes of forests. Some of these losses can be reversed through succession, assuming there is sufficient time to restore depleted stores such as soil organic matter. Continued environmental change will stimulate continued remixing of species, loss of vulnerable species, gains of less vulnerable ones, and more dissimilarity with historical forests. Novel forests are an answer to the changes induced by climate change and other anthropogenic disturbances, and as such require conservation measures, because as they mature, novel forests usually diversify and help restore lost biodiversity. We also review strategies to conserve biodiversity and optimize ecological services using novel forest succession. [ABSTRACT FROM AUTHOR]

Urban parks are likely the last green areas to preserve fauna diversity in urban ecosystems. We predicted that 1) species richness and ant diversity would increase with increasing park size, and species richness and ant diversity would be inversely related to distance from a peri-urban forest. 2) Larger ants would be predictably prevalent in less-complex habitats but the reverse should be true for small ants. The study was conducted in 47 parks of varying size located in Taichung City, Taiwan. In total, 14,324 ant individuals from 50 morphospecies and 22 genera were collected. No relationship between ant diversity and distance from a peri-urban forest. No significant clustering in functional composition with increasing park size and distance from a peri-urban forest. However, urban ant diversity marginally increased with increasing park size. Larger parks, characterize by heterogeneous fine-scale habitats, had the highest ant species and abundance of ants. The prevalences of opportunist, generalised myrmicinae (GM), and cryptic ant species were linked to increased soil moisture, number of tree species, and leaf litter depth. The positive association between GM and the number of trash bins. Our finding disproved the size-grain hypothesis, but hotter ground surface favored the presence of long-legged ants. The significant association between head width, inter-eye distance, eye width, and environmental variables such as understory vegetation cover, leaf litter depth, and soil temperature suggest that predaceous ants might be prevalent in heterogeneous fine-scale local microhabitats. In conclusion, our study evidenced the importance of heterogeneous fine-scale habitats in urban park to biodiversity. [ABSTRACT FROM AUTHOR]

Recently, the native species Frankliniella intonsa (Trybom) (Thysanoptera: Thripidae) has been found to be regionally dominant over its invasive congener Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) in Korea. To understand the variation in patterns of occurrence in the field, the effect of competition on the biological attributes of the 2 thrips species was assessed in the laboratory. In a behavioral study, the effect of inter- and intraspecific competition in honey or pollen feeding was observed in a glass-slide arena, and we found both reproduction and longevity to be more reduced in F. occidentalis than in F. intonsa by competition. However, the extent of feeding marks on bean leaves made by both species (in competition) was not significantly different from that made by each species separately, except in the case of the F. intonsa larvae. In an experiment on potted bean plants, competition caused a greater reduction in numbers of F. occidentalis progeny than that of F. intonsa progeny. In behavioral observations, guarding and feeding times of adult F. intonsa were 8.5 and 1.5 times longer on honey, and 42.8 and 1.3 times longer on pollen than F. occidentalis, respectively. However, in intraspecific competition, none of the behavioral parameters in pollen feeding showed significant differences in either species, except for the "confronting" behavior. In conclusion, both interference and exploitation competition exist between the 2 thrips species, and in laboratory studies F. intonsa was more persistent, not only at feeding and guarding food sources, especially in the adult stage, but also in displaying higher reproduction and longevity. These may be the underlying mechanisms for the asymmetrical pattern of occurrence of the 2 thrips in the field. [ABSTRACT FROM AUTHOR]

The aim of this study was determination of diversity, dominance and species richness of intertidal zone crabs of coastal field of Bushehr seaport. 9 stations were selected for sampling in the inter-tidal zone and sampling bed sediments was done in both warm (August 2015) and cold (December 2015) seasons using Quadrate (25×25 cm) randomly. Samples were preserved by using 10% buffered formalin and transported to the laboratory and counted and identified. More over physicochemical properties of water such as temperature, pH, dissolved oxygen (DO) and water salinity were also measured in each station. Diversity index was investigated using Shannon-Weaver formula, dominancy index was investigated using Simpson formula, and species richness was investigated using Margalof formula. The identified samples were totally 13 species from 7 families and 1 order. The most frequent identified families in seasons were Grapsidae , Porcellanidae and Xanthidae. According to the results of ANOVA, there were significant differences between frequency changes of crabs in all stations (p0.05). Also results of this study indicate that the most diversity rate (1.916) was in station 3 and warm season, the most species richness rate (4.454) was in station 3 and warm season and the most dominancy rate (1.000) was in station 1, 2, 9 and warm season. At the end of study, we can conclude that diversity of inter-tidal zone crabs in Bushehr seaport coastline was low.

Studies of stoichiometric homeostasis in different types of plant species growing in alpine steppe environments are important in understanding the fitness and nutrient-use strategies of alpine plants in northern Tibet, which may be correlated with species dominance and stability. We used an N- and P-addition experiment to investigate the stoichiometric homeostasis N (HN) in the foliage of different plant species in the Stipa purpurea steppe of the Tibetan Plateau from 2013 to 2016. The concentration of N in the foliage of different types of plants increased significantly with the amount of N added. We found that the HN value of the foliage of alpine steppe plants was much lower than that of plants in temperate grasslands and grasslands with tall grass, suggesting that these alpine plants can absorb more nutrients when they are available. There was no difference in the HN values for different alpine plant species, which is also different from previously reported results for other types of grasslands. Furthermore, the temporal stability and dominance of species was not significantly correlated with the foliage HN value of the species. Our results suggest that the HN value of plant foliage in an alpine steppe environment little affected the species dominance and stability seen in the control and N-addition plots at the species level, which is in conflict with the results from temperate grasslands. The different types of species in this alpine steppe environment show the same nutrient utilization strategies (low HN value, about 2) for coping with a variable and limited supply of nutrients. [ABSTRACT FROM AUTHOR]

Context The productivity-diversity relationships have been extensively studied in various forest ecosystems, but key mechanisms underlying the productivity-diversity relationships still remain controversial. Aims The objective of this study is to explore the productivity-diversity relationships at the community level, and to investigate the roles of individual species in shaping the community-level relationships between productivity and diversity under different forest types. Methods The study was conducted in two fully stem-mapped temperate mixed forest plots in Northeastern China: a natural secondary forest plot, and an old-growth forest plot. An individual-based study framework was used to estimate the productivitydiversity relationships at both species and community levels. A homogeneous Thomas point process was used to evaluate the significance of productivity-diversity relationship deviating from the neutral. Results At the species level, most of the studied species exhibit neutral productivity-diversity relationship in both forest plots. The percentage of species showing negative productivity-diversity relationship approaches linearly a peak value for very close neighborhoods (the secondary forest plot: r = 3 m, 38%; the old-growth forest plot: r = 4 m, 42%), and then decreases gradually with increasing spatial scale. Interestingly, only a few species displayed positive productivity-diversity relationship within their neighborhoods. Dominant species mainly exhibit negative productivity-diversity relationship while tree species with lower importance values exhibit neutral productivity-diversity relationship in both forests. At the community level, a consistent pattern of productivity-diversity relationship was observed in both forests, where tree productivity is significantly negatively associated with local species richness. Four biomass-dominant species (Juglans mandshurica Maxim., Acer mono Maxim.,Ulmus macrocarpa Hance and Acer mandshuricum Maxim.) determined a negative productivity-diversity relationship at the community level in the secondary forest plot, but only one species (Juglans mandshurica) in the old-growth forest plot. Conclusion The productivity-diversity relationship is closely related to the dominance of individual species at the species level. Moreover, this analysis is the first to report the roles of biomass-dominant species in shaping the productivity-diversity relationship at the community level. [ABSTRACT FROM AUTHOR]

Dominance and evenness can be two sides of the same coin or opposite ends of a spectrum. Although evenness and diversity are community-level concepts, dominance can be applied at both community and species scales. Nevertheless, there is not a metric applicable at both these scales that are unified with a single mathematical framework in the existing literature. Here, by extending Lloyd's meaning crowding concept from the population to community scale, we propose a dominance concept and associated metrics that are applicable at both scales. Such metrics can act as proxies for diversity in diversity-stability and diversity-ecosystem service analyses or for population abundance in species interaction network analysis and population stability analysis, with advantages in cross-scale and unified analyses. Our concept of dominance includes three measures (metrics) that link communities and species. The metrics have the same mathematical form, but different interpretations at the community and species scales. Our community-level metric is a function of Simpson's (1949) diversity index, for which we present a rigorous mathematical proof. Our species-level metrics quantify the difference between community dominance and the dominance of a virtual community whose mean population size, per species, equals the population size of the focal species. We demonstrate the use of these metrics using data from a longitudinal study of the human vaginal microbiome and provide new insights relevant for microbiome stability and disease etiology at the community scale. The new metrics also can be used for species dominance network (SDN) analysis at the species scale. Since the species dominance is a function of both species (population) abundance and community dominance, it has an advantage of capturing both community-scale global and species-scale local information, which becomes even more evident when it is used to construct SDNs. These results demonstrate the significance and applications of our unified dominance concept and metrics. [ABSTRACT FROM AUTHOR]

Aims Lianas are expected to influence composition, structure and functioning of forest systems due to unequal distribution across the potential set of host plants. However, our understanding of mechanisms associated with preferences for specific hosts is still limited, and so is our ability to discern between endogenous and exogenous forces driving forest dynamics in the long run. In this paper, we evaluated whether the dominant liana Hedera helix can indirectly contribute to the eventual dominance of the small multi-stemmed tree Corylus avellana in a remnant temperate forest in central Iberian Peninsula from comparatively reduced liana infestation on C. avellana relative to co-occurring woody species. Methods Through principal component analysis and co-occurrence analysis, we studied the distribution and spatial association between woody species and the liana H. helix. We analyzed the relationship between the number of species in a plot and the number of species infested by the liana to test the hypothesis that H. helix is a generalist liana. Through generalized linear mixed models, we tested the dynamic-multi-stemmed growth form of C. avellana as a plausible life strategy to withstand, in the long run, the liana infestation. In particular, we tested (i) the relationship between stem size and the probability of H. helix infestation including all the tree species within plots and (ii) the relationship between stem size and mortality as evidence of the stem turn over in the tree C. avellana. Important Findings Our results indicate that H. helix and C. avellana significantly cooccur in mature stands of this remnant temperate forest where pioneer woody species are absent. Hedera helix severely infests all the woody species whenever stem size exceed ≈25 cm perimeter and there is physical contact at the base of the stem. This implies that all the trees in the community are potential hosts for H. helix. Mixed models indicate that both, infestation by H. helix and stem mortality, are positively related to C. avellana stem perimeter. Reduced longterm infestation of the liana by means of a multi-stemmed growth form with high stem turnover in C. avellana might be an advantage with respect to unipodial tree species. Thus, the liana-tree coexistence pattern may be interpreted as an indirect positive interaction that, contrary to previous findings, results here in species dominance instead of species coexistence. [ABSTRACT FROM AUTHOR]

Background: Soil amendment with biochar can increase biological nitrogen fixation (BNF) and improve growing conditions for legumes, while such effects may alter when biochar properties change with time (biochar aging).Methods: We examined BNF and competitiveness of legumes in a mixed pasture (dominated by clover, Trifolium repens) after 26 months of biochar amendment (field aged biochar) and in a pot study with grass (Lolium perenne) and clover mixture using fresh and chemically aged biochars.Results: In both studies, the fraction of N derived from symbiotic fixation (%Ndfa) was not affected by aged biochar treatments, while it reduced from 73% in the control to 68% with fresh biochar addition in the pot study. However, this reduction in %Ndfa was compensated with greater biomass production resulting in the largest amount of N fixed with fresh biochar application. The amount of N fixed was reduced by field aged biochar, although it was not affected by chemically aged biochars. Moreover, in the field study grasses became more competitive than legumes with biochar, while such an advantage by grasses was not observed in the pot study.Conclusions: Aging of biochar can reduce BNF and competitiveness of legumes in mixed pastures with significant implications for pasture management. [ABSTRACT FROM AUTHOR]

Climate change is having profound influences on Arctic tundra plant composition, community dynamics, and ecosystem processes. Stoichiometric homeostasis (H), the degree to which a plant maintains its internal nutrient concentrations independent of nutrient variations in its environment, may be a useful approach to predict the impacts of these influences. In this case study, we used fertilization manipulation data to calculate homeostasis indices based on nitrogen (HN), phosphorus (HP), and nitrogen to phosphorus ratios (HN:P) of aboveground tissues for seven common tundra vascular species belonging to three growth forms. We then analyzed species H relationships with dominance, spatial stability, and responsiveness to various experimental manipulations. Each of the H indices was correlated amongst tissue types within each species and was generally highest in ericoid mycorrhizal host species and lowest in the ectomycorrhizal birch. Species HP and HN:P were consistently positively correlated with aboveground biomass within the controls and across all manipulations. Furthermore, these same species were spatially stable across experimentally warmed field plots. Stoichiometric homeostasis theory has been successful in predicting grassland community dynamics. This first test of its applicability across a variety of Arctic plant growth forms highlights its considerable potential in predicting tundra plant community structure and responses to environmental change.

The effect of tertiary treated sewage effluents on the plant cover and the physico-chemical properties of the surface soil (environmental characteristics) before and after the Al Rass sewage plant was investigated. The data were illustrated via TWINSPAN and canonical correspondence analysis (CCA). Five sites, 1 km apart, after the discharge point and one site (control site) before the sewage plant were examined. Eleven vegetation characteristics and ten physico-chemical properties of surface soil were studied. The obtained results revealed that discharging of treated sewage effluents altered quantitatively and qualitatively the pattern of species dominance and the physico-chemical properties of the soil. Soil electrical conductivity (EC), total dissolved solids (TDS), organic matters (OM), soluble cations, and soluble anions showed increased values compared to the control (resulting in salination), whereas soil pH decreased as a result of sewage disposal. It was also noticed that the physico-chemical values of EC, TDS, Ca++, Mg++, Na+, Cl- after the sewage plant were higher than the permissible limits for agriculture recommended by FAO, whereas K+ and HCO3- were within the recommended values. The dominance of Suaeda vermiculata Forssk. ex J.F.Jmel. after the sewage plant and its absolute absence before the sewage plant may be used as an environmental bioindicator of pollution. [ABSTRACT FROM AUTHOR]

Tropical and subtropical dry forest life zones support forests with lower stature and species richness than do tropical and subtropical life zones with greater water availability. The number of naturalized species that can thrive and mix with native species to form novel forests in dry forest conditions in Puerto Rico and the US Virgin Islands is lower than in other insular life zones. These novel dry forests are young (<60 years) with low structural development, high species dominance, and variable species density. Species density is low during initial establishment and increases with age. At the 1-ha scale, novel forests can have greater species density than mature native forests. Species groups, such as nitrogen-fixing species, and other naturalized species that dominate novel dry forests, have a disproportional influence on forest element stoichiometry. Novel dry forests, compared to the mean of all forest species assemblages island-wide, tend to have fallen leaf litter with lower than average manganese and sodium concentrations and lower than average C/N and C/P ratios. After accounting for significant differences in stand age, geology, and or precipitation, novel dry forests compared to native dry forests have higher C anomalies, lower Ca and Na anomalies, and lower C/N ratio anomalies. Taken together, these characteristics may influence litter decomposition rates and the species composition, diversity, and food web dynamics in litter and soil. Novel dry forests also contribute to the conservation of native plant species on highly degraded lands. [ABSTRACT FROM AUTHOR]

Native and introduced species can coexist in rich ecosystems where competition for resources is less intense; however, native species can be excluded from suitable habitats hosting a high abundance of introduced species. To test these hypotheses, we estimated the probability of introduced bees (buff-tailed bumblebees and honeybees) to co-occur and dominate giant bumblebees in forested landscapes of northern Patagonia. We evaluated the effects of 29 remote-sensing variables of forest ecosystems on bee abundance using data from 56 landscapes. Then, we used a probabilistic Bayesian model to estimate the effects of the most important predictors of bee abundance on their co-occurrence and dominance probabilities. Introduced and native bees exhibited heterogeneous and scale-dependent responses to environmental conditions, with only six variables affecting their co-occurrence and dominance probabilities. A high maximum temperature was associated with both a decreased co-occurrence and an increased dominance of introduced bumblebees, and the opposed pattern was found for vegetation continuous fields, an index of canopy continuity. Similar responses were found for the co-occurrence probability of honeybees and giant bumblebees. Thus, species dominance and co-occurrence changed differently along environmental gradients, with co-occurrence increasing as native and introduced species become more abundant. A high dominance of introduced bees in unsuitable habitats suggests interspecific competition is strengthened as resources become scarcer, thus reinforcing the idea that abiotic and biotic filters interact with each other. • Introduced and native bees had heterogeneous responses to environmental conditions. • High temperatures caused decreased co-occurrence and increased dominance. • The opposite pattern was found for Vegetation Continuous Fields. • Co-occurrence increased as native and introduced species become more abundant. • A high dominance of introduced bees was found in unsuitable habitats. [ABSTRACT FROM AUTHOR]

Macroalgal distribution varies with prevailing environmental gradients in fjords, particularly in glacial fjords such as Kongsfjorden, Svalbard. This survey by scuba-diving in 1996 and 1998 was the first to determine species composition, dominance and distribution of macroalgae along the entire length axis of a fjord in the Arctic. Macroalgal distribution was determined quantitatively by frame sampling and with digital video along transects at five hard-bottom locations from outer to inner fjord and interpreted against environmental gradients of depth (0-30 m), substratum, wave exposure and distance from inner glacial front. Most species identified (>70%) belonged to the Arctic and Arctic-temperate biogeographic groups, often with limited distribution to inner or outer part of the fjord. Dominant species or species with wide geographic distribution were typically widely distributed along the fjord axis. Peaks in biomass varied from 5 to 10 m at the middle-to-outer fjord, whereas in the inner bay it peaked at <5 m. The biomass distribution of macroalgae was mainly related to depth and distance from the inner glacial bay, and varied with wave exposure and sediment cover. Climate-related changes, after our study, indicate that the macroalgal belt has become shallower at Hansneset in middle fjord, with increased biomass in the upper sublittoral zone because of higher temperature and less sea ice. Distribution and production of macroalgae and fauna in shallow regions of the Arctic are likely to increase in the future, particularly in areas subjected to ocean warming, such as Kongsfjorden and other fjords and coastal areas in Svalbard. [ABSTRACT FROM AUTHOR]