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Substantial evidence suggests that biodiversity can stabilize ecosystem function, but how it does this is less clear. In very general terms, the hypothesis is that biodiversity stabilizes function because having more species increases the role of compensatory dynamics, which occur when species in a community show different responses to the environment. Here, we focus on two forms of compensatory dynamics, cross‐scale redundancy (CSR) and response diversity (RD). CSR occurs when species respond to a disturbance at different scales such that scale‐specific disturbances do not negatively affect all species. RD occurs when species contributing to the same function show different responses to an environmental change. We developed a new analytical approach that can compare the strength of CSR and RD in the same dataset and used it to study native bee pollination of blueberry at 16 farms that varied in surrounding agricultural land use. We then asked whether CSR and RD among bee species are associated with the stability of blueberry pollination. Although CSR and RD were both present, only RD was associated with higher stability of pollination. Furthermore, the effects of RD on stability were due to a single widespread species, Andrena bradleyi, that is a specialist on blueberry and, unlike other bee species, was highly abundant at farms surrounded by intensive blueberry agriculture. Thus, the stabilizing effect we observed was attributable to an “identity effect” more than to species richness per se. Our results demonstrate how CSR and RD can be empirically measured and compared and highlight how the theoretical expectations of the biodiversity–ecosystem functioning field are not always upheld when confronted with real‐world data. [ABSTRACT FROM AUTHOR]

To describe the species composition of fish larvae and juveniles in the Nanji Islands, monthly collection was conducted at 12 stations around the Nanji Islands from March 2023 to February 2024 by using horizontal tow at the surface layer. The fish larvae and juveniles were collected by a larva net (1.3 m mouth diameter, 0.5 mm mesh aperture). A total of 6446 fish larvae and juveniles were collected, belonging to 59 species and 54 genera in 11 families. Most of them were preflexion larvae (93.31%). Gobiidae, with eight species, was the most diverse family. Based on the index of relative importance (IRI) result, the dominant species was Sebastiscus marmoratus (Cuvier, 1829), accounting for 84.52% of the total number of samples collected. The common species were Stolephorus commersonii Lacepède, 1803; Omobranchus elegans (Steindachner, 1876); Nibea albiflora (Richardson, 1846); Parablennius yatabei (Jordan & Snyder, 1900); Lateolabrax maculatus (McClelland, 1844); and Odontamblyopus lacepediiand (Temminck & Schlegel, 1845). Other species were all rare species. The highest species number was in September (18 species), and the highest density was in December. Only one fish larva was collected in April. Pielou's evenness index was highest in November, while Margalef's richness index and Shannon–Wiener diversity were highest in September. The result of cluster analysis showed that the 11 months (except April) could be divided into four groups. The species number, density, and three diversity indexes showed no significant correlation with temperature and salinity. [ABSTRACT FROM AUTHOR]

Biological assessments typically involve field surveys that are time‐consuming and require taxonomic expertise. Floristic Quality Assessment, a popular bioassessment method for wetlands and other ecosystems, generally assumes a comprehensive or representative species list for accurate implementation. We explored this long‐held belief by analyzing an essential floristic quality metric (mean conservatism) across real and simulated gradients of species representation in two disparate case studies. In one study, we incrementally removed species at random from an exhaustive floristic survey of a suburban wetland complex in northeast Ohio. Bootstrapping mean conservatism at each removal step, precision scarcely decreased with 10%–30% species loss, becoming noticeable only when about 50% or fewer species remained. For the other study, we exploited varying percentages of dominant species available from hundreds of single‐visit wetland determination surveys throughout Illinois. Comparing dominants‐only mean conservatism with total species mean conservatism, the relationship steadily improved as dominants covered progressively larger fractions of native richness, ranging from r2 = 0.12 at ≤10% dominants to 0.74 at >40% dominants. Both exercises suggest that community size is more important than taxonomic representation or inventory completeness per se in determining accuracy. Our results indicate that full or representative checklists are not a prerequisite for reliable Floristic Quality Assessment, supporting the investigation and potential use of taxonomic shortcuts and empowering a wide range of users beyond expert field botanists. [ABSTRACT FROM AUTHOR]

Dominant species are crucial in regulating the structure and productivity of plant communities. Adaptation strategies to climate change vary among the dominant species of different life types. However, the responses of the ecological niches of dominant species to warming and precipitation in semi-arid grasslands and their impacts on community structure and function are unknown. This study involved conducting a long-term experimental simulation of warming and increased precipitation on grasslands in Inner Mongolia and studying population dynamics, ecological niches, and their responses to the structure and function of the community species of two dominant plants, L. chinensis (perennial rhizome grass) and S. krylovii (perennial clumped grass). The results show that the niche width of L. chinensis increased and S. krylovii decreased under warming and increased precipitation conditions. The overlap of L. chinensis and S. krylovii decreased under the same conditions. The niche widths of L. chinensis and S. krylovii were 1.22 for the control (C), 1.19 and 1.04 under warming (W) conditions, 1.27 and 0.97 under warming plus precipitation (WP) conditions, and 1.27 and 1.24 under the conditions of precipitation addition (P). The niche overlap of L. chinensis and S. krylovii were 0.72 in C, 0.69 in W, 0.68 in WP, and 0.82 in P. The biomass share and importance value of L. chinensis increased, and those of S. krylovii decreased in response to warming and precipitation. The effects of warming on species diversity and community stability are primarily influenced by the effects on the niche breadth of S. krylovii. Combined with our previous study, L. chinensis will offer more resources in communities in warmer and wetter steppe climates in the future. However, this is not conducive to community diversity. [ABSTRACT FROM AUTHOR]

The characteristics of zooplankton communities and the relationships with the aquatic environment in the shallow waters of northern Liaodong Bay were investigated. Spot sampling surveys were carried out in April, June, September, and November 2018 to assess zooplankton species composition and diversity, abundance, biomass, and dominant species, and the associated relationships with environmental factors. A total of 45 species of zooplankton were recorded in the survey, comprising 18 Copepoda, 2 Amphipoda, 1 Mysidacea, 1 Decapoda, 1 Chaetognatha, 7 Hydrozoa, 1 Tunicate, and 14 planktonic larvae. Overall, the most dominant species was Aidanosagitta crassa (Tokioka, 1938), with copepods and planktonic larvae also dominating the zooplankton community. However, there was a seasonal alternation of species dominance. A cluster analysis showed that the zooplankton community in spring differed from other seasons and was mostly influenced by suspended particulate matter. Bioenv analysis indicated the main environmental factor affecting the zooplankton community in spring was suspended particulate matter. In summer, the determining variables were temperature, dissolved inorganic nitrogen (DIN), nitrate, and sediment pH. In autumn, temperature, DIN, and nitrate were determining variables, and dissolved oxygen (DO) and DIN in winter. Zooplankton abundance and biomass were influenced by salinity, suspended particulate matter, chemical oxygen demand (COD), chlorophyll, and water and sediment pH. In general, the shallow sea area north of Liaodong Bay is rich in zooplankton species and exhibits significant seasonal variations. Human activities have disturbed the biological community to a certain extent, and the environmental factors in this area are closely related to the diversity of zooplankton species. [ABSTRACT FROM AUTHOR]

Abstract Dominant species occupy a pivotal role in plant community, influencing the structure and function of the ecosystem. The spatial distributions of dominant species can react to the effect of different grazing intensities, thereby reflecting their tolerance and adaptive strategies toward grazing. In this study, geostatistical methods were mainly used to study the spatial distribution characteristics of Stipa krylovii Roshev. and Leymus chinensis (Trin.) Tzvel. species at two interval scales (quadrat size 5 m × 5 m, 10 m × 10 m) and two treatments (free grazing, FG, 1.66 sheep·ha− 1·a− 1; control, CK, 0 sheep·ha− 1·a− 1) in typical steppe of Inner Mongolia. A systematic sampling method was used in each 100 m × 100 m representative sample plots to obtain the height, coverage, and density of all species in the community. The results showed that grazing altered the concentrated distribution of S. krylovii and the spatial mosaic distribution pattern of S. krylovii and L. chinensis while having no effect on the spatial clumped distribution of L. chinensis. It also found that the spatial distributions of dominant species are primarily affected by structural factors, and random factors such as long-term grazing led to a transition of S. krylovii from a concentrated distribution to a small patchy random pattern should not be overlooked. Our findings suggest that long-term grazing alters the spatial distribution pattern of dominant species and that adaptive strategies may be the key for maintaining the dominant role of structural factors.

Taking the elfin forest community on the top of the mountain in the Mulinzi National Nature Reserve in Hubei as the research object, the ecological niche, interspecific connection characteristics, and community stability of the dominant species in the elfin forest community on the top of the mountain were analyzed, and the resource utilization strategy and survival mechanism of plants in unique habitats were explored. Based on a field survey, the niche width, niche overlap index, variance ratio method, chi-squared test, Spearman's rank correlation test, Pearson's correlation test, and M. Godron stability assay were used to analyze the niche, interspecific connection characteristics, and stable communities of the dominant species in the elfin forest community at the top of Mulinzi Mountain. Quercus glauca had the highest significant value and niche width and was found to be the dominant species in the community. Enkianthus serrulatus, followed by Sorbus caloneura, were the main species in the community, but the order of importance and niche width were significantly different. Among the 190 species pairs comprising 20 dominant species, 21. 05%of the species pair niche overlap index values were more significant than 0. 5, and 50. 00%were between 0. 2 and 0. 5. There is a common phenomenon of niche overlap among populations, and dominant species have a high degree of niche overlap with other populations. The overall association with the community showed an insignificant positive association. The chi-squared test showed that 98. 95%of the species pairs showed an insignificant or no association. Pearson's and Spearman's rank correlation tests also showed no significant association between most species, and the association between various groups was weak. Most species in the elfin forest community at the top of Mulinzi Mountain were loosely connected, and competition with the dominant species for environmental resources was weak. Harsh environmental conditions altered the survival and resource utilization strategies of various species in the community. Community structures have adapted to such habitats, and environmental resources have been utilized more fully. The community is relatively stable. [ABSTRACT FROM AUTHOR]

Dominant species occupy a pivotal role in plant community, influencing the structure and function of the ecosystem. The spatial distributions of dominant species can react to the effect of different grazing intensities, thereby reflecting their tolerance and adaptive strategies toward grazing. In this study, geostatistical methods were mainly used to study the spatial distribution characteristics of Stipa krylovii Roshev. and Leymus chinensis (Trin.) Tzvel. species at two interval scales (quadrat size 5 m × 5 m, 10 m × 10 m) and two treatments (free grazing, FG, 1.66 sheep·ha− 1·a− 1; control, CK, 0 sheep·ha− 1·a− 1) in typical steppe of Inner Mongolia. A systematic sampling method was used in each 100 m × 100 m representative sample plots to obtain the height, coverage, and density of all species in the community. The results showed that grazing altered the concentrated distribution of S. krylovii and the spatial mosaic distribution pattern of S. krylovii and L. chinensis while having no effect on the spatial clumped distribution of L. chinensis. It also found that the spatial distributions of dominant species are primarily affected by structural factors, and random factors such as long-term grazing led to a transition of S. krylovii from a concentrated distribution to a small patchy random pattern should not be overlooked. Our findings suggest that long-term grazing alters the spatial distribution pattern of dominant species and that adaptive strategies may be the key for maintaining the dominant role of structural factors. [ABSTRACT FROM AUTHOR]

Simple Summary: The construction of dams in Mabiehe River has significantly impacted fish diversity, resulting in reduced species richness and diversity within dammed sections compared to undammed segments of the river. The environmental DNA (eDNA) technique is effective in assessing fish diversity in the challenging environment of canyon rivers. The successful detection of a variety of species, including both protected and exotic ones, highlights the robustness of eDNA as a comprehensive monitoring tool. Investigating fish diversity in canyon rivers through conventional fish surveys is challenging due to precipitous conditions, including steep slopes, rapid water flow, and complex habitats. Additionally, intensive construction of dams has further complicated the understanding of contemporary fish diversity in these rivers. In this study, we used the environmental DNA (eDNA) technique to assess fish diversity and examine the effects of dams on fish diversity in the Mabiehe River, a canyon river in the upper reaches of the Pearl River drainage. Water samples from 15 sampling sites were collected, yielding 9,356,148 valid sequences. Utilizing the NCBI public database, a total of 60 freshwater fish species were identified, with Carassius auratus, Cyprinus carpio, and Pelteobagrus fulvidraco being the most dominant species in the Mabiehe River. We also detected one nationally protected fish species, three provincially protected fish species, and six exotic species in this river. Furthermore, eDNA analyses demonstrated that the lotic river sections harbor more species and greater diversity than dammed sections, suggesting that dams might exert significant impacts on local fish diversity. Overall, this study supports the effectiveness of the eDNA technique as a complementary tool to traditional field surveys for monitoring fish biodiversity in canyon rivers. [ABSTRACT FROM AUTHOR]

Understanding how plant functional traits respond to mining activities and impact metal(loid)s accumulation in dominant species is crucial for exploring the driving mechanisms behind plant community succession and predicting the ecological restoration potential of these plants. In this study, we investigated four dominant herbaceous species (Artemisia argyi, Miscanthus sinensis, Ficus tikoua, and Ageratina adenophora) growing on antimony (Sb) mining sites (MS) with high Sb and arsenic (As) levels, as well as non‐mining sites (NMS). The aim was to analyze the variations in functional traits and their contribution to Sb and As concentrations in plants. Our results indicate that mining activities enhanced soil nitrogen (N) limitation and phosphorus (P) enrichment, while significantly reducing the plant height of three species, except for F. tikoua. The four species absorbed more calcium (Ca) to ensure higher tolerance to Sb and As levels, which is related to the activation of Ca signaling pathways and defense mechanisms. Furthermore, plant Sb and As concentrations were dependent on soil metal(loid) levels and plant element stoichiometry. Overall, these findings highlight the regulatory role of plant element traits in metal(loid) concentrations, warranting widespread attention and further study in the future. [ABSTRACT FROM AUTHOR]

A growing number of studies have demonstrated that biodiversity is a strong and positive predictor of ecosystem temporal stability by simultaneously affecting multiple underlying mechanisms of stability, that is dominance, asynchrony and averaging effects. However, to date, no study has disentangled the relative role of these key mechanisms of stability in biodiversity experiments.We created a species richness gradient by mimicking a loss of rare species and assessed the role of species richness on community stability and, more importantly, quantified the relative role of three stabilizing mechanisms, that is dominance (stabilization due to stable dominants compared to the rest of the species in the community), asynchrony (stabilization due to temporal asynchrony between species), and averaging effects (pure effect of diversity) on community stability across a species richness gradient.We found that extreme species loss negatively impacted community stability, but just three species were enough to stabilize biomass production to a level similar to highly diverse communities. However, the similar stability of communities resulted from differing contributions from each stabilizing mechanism, depending on the community diversity. Since less abundant species were more temporally variable, species loss stabilized the populations of the remaining species. The loss of rare and subordinate species reduced the dominance and averaging effects, but increased the asynchrony effect. Hence, the asynchrony effect played a major role in the stability of species poor communities, while the averaging effect drove most of the stability of species rich communities. Overall, dominance played only a minor role, accounting for 5%–15% of the stabilization, while asynchrony and averaging effects were dominating forces contributing to ~85%–95% of the total stabilization.Synthesis. This study highlights the importance of biodiversity and roles of dominant and rare species for long‐term community stability and, for the first time, disentangles relative roles of dominance effect, asynchrony and averaging effect on community stability in a real‐world biodiversity experiment. [ABSTRACT FROM AUTHOR]

The nematode community was studied at eight stations in the eastern part of the East Siberian Sea shelf (43 m), along the slope, and at a deep-sea site (1350 m). All samples (depth range 43–1350 m) were collected with a MUC corer in the northeastern part of the East Siberian Sea during cruise ARA10C of the R/V Araon in 2019. The taxonomic composition of the nematode community is typical of the Siberian Arctic seas in summer–autumn. The nematode diversity of the East Siberian Sea is poor in comparison with other Russian Arctic seas. Nematode genera typical of the shelf and deep sea were identified. The nematodes density in the uppermost sediment layer increases from the southernmost station along the shelf, amount a maximum on the outer shelf, and decreases downhill with the minimum at the deepest site. It is suggested that the high nematode abundance and diversity on the outer slope was provided by high organic matter fluxes at the boundary of water masses, increasing the oxygen and silt content in sediments. [ABSTRACT FROM AUTHOR]

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Lianzigou deposit, which has an Au–Te paragenetic association, is hosted in plagioclase gneiss of the Qincanggou Formation in the Taihua Group in the Xiaoqinling region, central China. This quartz vein-type Au deposit comprises native Au and a variety of tellurides. The latter include calaverite (AuTe2), krennerite (Au3AgTe8), petzite (Au3AgTe2), hessite (Ag2Te), melonite (NiTe2), and altaite (PbTe). Four stages have been recognized in this deposit: stage I consists of K-feldspar and quartz; stage II is of milky quartz veins accompanied by coarse-grained disseminated and lumps of pyrite with weak Au mineralization; stage III is composed mainly of Au, tellurides, and sulfides; and stage IV is characterized by abundant carbonate and quartz. Based on mineral assemblage and thermodynamic data, we estimated the physicochemical conditions of the main metallogenic stages. Based on thermodynamic modelling, the physicochemical conditions of Au–Ag–Te mineral associations were estimated. The Au–Ag–Te minerals from stage III formed mainly under conditions of logƒO2 = −43.15 to −33.31, logƒH2S = ~−9.29, pH < 7, logfTe2 = −10.6 to −9.8 and logαAu+/αAg+ = −7.2 to −6.5. In contrast, the physicochemical conditions of stage II were higher, specifically pH (8.3–8.5) and logƒO2 (−34.90−31.96). In the ore-forming fluids of the Lianzigou deposit, the dominant Au species was Au(HS)2− while the dominant Te species were HTe−(aq) and Te22−(aq). Moreover, the Au–Ag–Te metal associations in the Lianzigou Au deposit were derived from mantle materials related to lithospheric thinning of the eastern North China craton in the Early Cretaceous under an extensional tectonic system. [ABSTRACT FROM AUTHOR]

To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang Province, East China, the main stream and the Shanxi-Zhaoshandu Reservoir in the downstream were chosen as the study area, for which 22 sampling sites were designated. Sampling was conducted in September 2021, January, May, and July 2022. Phytoplankton species were identified from both quantitative samples and in-vivo observations. Phytoplankton was quantified by direct counting. Results show that there were 98 species belonging to 6 phyla and 78 genera. In addition, to clarify the niches of the dominant phytoplankton species and their interspecific association, the dominance index was calculated, and a comprehensive analysis was conducted including niche width, niche overlap value, ecological response rate, overall association, chi-square test, and the stability. The phytoplankton community exhibited characteristics of a Cyanobacteria-Chlorophyta-Diatom type community, showing higher diversity in spring and lower diversity in summer. Among 11 dominants phytoplankton species from 3 phyla, both frequency and dominance degree varied seasonally, of which Microcystis sp. was the dominant species in Spring, Autumn, and Winter. The niche widths of the dominant species ranged from 0.234 to 0.933, and were categorized into three groups. The niche overlap values of the 11 dominant species ranged from 0.359 to 0.959, exhibiting significant seasonal differences—highest in winter followed by autumn, spring, and summer in turn. The overall correlation among dominant species in all four seasons revealed a non-significant negative association, resulting in an unstable community structure. A significant portion (84.2%) of species pairs displayed positive associations, suggesting a successional pattern where Diatoms dominated while other dominant species shared resources and space. Despite this pattern, stability measurements indicated that the dominant species community remained unstable. Therefore, careful monitoring is recommended for potential water environment issues arising from abnormal proliferation of dominant species in the watershed during winter. This research built a theoretical foundation with a data support to the early warning of eutrophication and provided a reference for water resources management in similar watersheds along the eastern coast of China. [ABSTRACT FROM AUTHOR]

A substantial body of empirical evidence suggests that anthropogenic disturbance can affect the structure and function of grassland ecosystems. Despite this, few studies have elucidated the mechanisms through which grazing and mowing, the two most widespread land management practices, affect the stability of natural grassland communities. In this study, we draw upon 9 years of field data from natural grasslands in northern China to investigate the effects of gazing and mowing on community stability, specifically focusing on community aboveground net primary productivity (ANPP) and dominance, which are two major biodiversity mechanisms known to characterize community fluctuations. We found that both grazing and mowing reduced ANPP in comparison to areas enclosed by fencing. Grazing reduced community stability by increasing the likelihood of single‐species dominance and decreasing the relative proportion of nondominant species. In contrast, mowing reduced the productivity of the dominant species but increased the productivity of nondominant species. As a consequence, mowing improved the overall community stability by increasing the stability of nondominant species. Our study provides novel insight into understanding of the relationship between community species fluctuation‐stability, with implications for ecological research and ecosystem management in natural grasslands. [ABSTRACT FROM AUTHOR]

Elucidating changes in the structure and function of plant communities along different elevation ranges will help researchers to analyze the strategies plant communities use in environments and processes influencing niche differentiation. The aims of this paper are to reveal the underlying mechanisms and ecological processes governing the development of subtropical forest ecosystem plant communities. This paper analyzes the forest vegetation of the Wuyi Mountains across the following three elevation ranges: low elevation, mid elevation, and high elevation, spanning from 560 to 2150 m. Twenty and twenty-three dominant tree and shrub layer species, respectively, were identified based on their importance values, and their niches and species associations were further analyzed based on the elevation range. The results showed interspecific associations between tree and shrub species, with the strongest associations observed at mid-elevations. The analysis of niche width and overlap showed that the number of pairs of species with a higher degree of niche overlap decreased with increasing elevation, suggesting that resource use varied at different elevations for both tree and shrub layer species, which may be related to the adaptive capacity of plants at different elevations to the environment and resource use strategies. These findings should contribute to a deeper understanding of the ecological functioning and structural framework of plant communities on Wuyi Mountain. [ABSTRACT FROM AUTHOR]

Human impacts on ecosystems are resulting in unprecedented rates of biodiversity loss worldwide. The loss of species results in the loss of the multiple roles that each species plays or functions (i.e., ecosystem multifunctionality) that it provides. A more comprehensive understanding of the effects of species on ecosystem multifunctionality is necessary for assessing the ecological impacts of species loss. We studied the effects of two dominant intertidal species, a primary producer (the seaweed Neorhodomela oregona) and a consumer (the shellfish Mytilus trossulus), on 12 ecosystem functions in a coastal ecosystem, both in undisturbed tide pools and following the removal of the dominant producer. We modified analytical methods used in biodiversity-multifunctionality studies to investigate the potential effects of individual dominant species on ecosystem function. The effects of the two dominant species from different trophic levels tended to differ in directionality (+/-) consistently (92% of the time) across the 12 individual functions considered. Using averaging and multiple threshold approaches, we found that the dominant consumer-but not the dominant producer-was associated with ecosystem multifunctionality. Additionally, the relationship between abundance and multifunctionality differed depending on whether the dominant producer was present, with a negative relationship between the dominant consumer and ecosystem function with the dominant producer present compared to a non-significant, positive trend where the producer had been removed. Our findings suggest that interactions among dominant species can drive ecosystem function. The results of this study highlight the utility of methods previously used in biodiversity-focused research for studying functional contributions of individual species, as well as the importance of species abundance and identity in driving ecosystem multifunctionality, in the context of species loss.

Tree species composition is essential information for forest management and remotely sensed (RS) data have proven to be useful for its prediction. In forest management inventories, tree species are commonly interpreted manually from aerial images for each stand, which is time and resource consuming and entails substantial uncertainty. The objective of this study was to evaluate a range of RS data sources comprising airborne laser scanning (ALS) and airborne and satellite-borne multispectral data for model-based prediction of tree species composition. Total volume was predicted using non-linear regression and volume proportions of species were predicted using parametric Dirichlet models. Predicted dominant species was defined as the species with the greatest predicted volume proportion and predicted species-specific volumes were calculated as the product of predicted total volume multiplied by predicted volume proportions. Ground reference data obtained from 1184 sample plots of 250 m2 in eight districts in Norway were used. Combinations of ALS and two multispectral data sources, i.e. aerial images and Sentinel-2 satellite images from different seasons, were compared. The most accurate predictions of tree species composition were obtained by combining ALS and multi-season Sentinel-2 imagery, specifically from summer and fall. Independent validation of predicted species proportions yielded average root mean square differences (RMSD) of 0.15, 0.15 and 0.07 (relative RMSD of 30%, 68% and 128%) and squared Pearson's correlation coefficient (r2) of 0.74, 0.79 and 0.51 for Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and deciduous species, respectively. The dominant species was predicted with median values of overall accuracy, quantity disagreement and allocation disagreement of 0.90, 0.07 and 0.00, respectively. Predicted species-specific volumes yielded average values of RMSD of 63, 48 and 23 m3/ha (relative RMSD of 39%, 94% and 158%) and r2 of 0.84, 0.60 and 0.53 for spruce, pine and deciduous species, respectively. In one of the districts with independent validation plots of mean size 3700 m2, predictions of the dominant species were compared to results obtained through manual photo-interpretation. The model predictions gave greater accuracy than manual photo-interpretation. This study highlights the utility of RS data for prediction of tree species composition in operational forest inventories, particularly indicating the utility of ALS and multi-season Sentinel-2 imagery.

Abstract Biological assessments typically involve field surveys that are time‐consuming and require taxonomic expertise. Floristic Quality Assessment, a popular bioassessment method for wetlands and other ecosystems, generally assumes a comprehensive or representative species list for accurate implementation. We explored this long‐held belief by analyzing an essential floristic quality metric (mean conservatism) across real and simulated gradients of species representation in two disparate case studies. In one study, we incrementally removed species at random from an exhaustive floristic survey of a suburban wetland complex in northeast Ohio. Bootstrapping mean conservatism at each removal step, precision scarcely decreased with 10%–30% species loss, becoming noticeable only when about 50% or fewer species remained. For the other study, we exploited varying percentages of dominant species available from hundreds of single‐visit wetland determination surveys throughout Illinois. Comparing dominants‐only mean conservatism with total species mean conservatism, the relationship steadily improved as dominants covered progressively larger fractions of native richness, ranging from r2 = 0.12 at ≤10% dominants to 0.74 at >40% dominants. Both exercises suggest that community size is more important than taxonomic representation or inventory completeness per se in determining accuracy. Our results indicate that full or representative checklists are not a prerequisite for reliable Floristic Quality Assessment, supporting the investigation and potential use of taxonomic shortcuts and empowering a wide range of users beyond expert field botanists.

The Yangtze River Estuary is the traditional habitat of fishery resources in China and also one of the crab fishing sites, but nowadays the crab resources have been seriously affected by high-intensity anthropogenic disturbance. To understand the composition and diversity of crab community following the fishing ban, six surveys were conducted from August 2022 to November 2023 using the single-bag trawl method. This study examined the crab community composition, biodiversity, resource density, spatiotemporal distribution patterns, and main influencing factors. Results indicated that a total of 14 crab species lived in the Yangtze River Estuary. Matuta planipes and Portunus trituberculatus were dominant crabs in summer 2022. P. trituberculatus, Eriochier leptognathus, and Charybdis japonica were dominant crabs in autumn 2022. Then, E. leptognathus and Eriocheir sinensis were dominant crabs in winter 2023. Notably, the largest numbers of dominant crabs appeared in spring 2023, including M. planipes, P. trituberculatus, E. leptognathus, C. japonica, and E. sinensis. Three same dominant crabs (M. planipes, P. trituberculatus, C. japonica) were identified in the summer and autumn of 2023. Thereinto, P. trituberculatus was the most dominant crab. The abundance and biomass trends of estuary crabs were winter< spring< autumn< summer. The community diversity index, evenness index, and richness index were winter< summer< autumn< spring, indicating the seasonal changes in abundance, biomass, and biodiversity. Correlation and redundancy analysis revealed that dissolved oxygen and salinity were the most critical environmental factors, which affect the changes in crab community in the estuary. This study revealed the changing characteristics of crab resources in the Yangtze River Estuary after the fishing ban, and provided the essential data and scientific basis for resource conservation and management decisions.

Based on original data obtained in 2017–2022 on the territory of two specially protected natural areas of regional significance, as well as literary sources and information from respondents, faunistic lists of birds were compiled, dominants and subdominants were identified. In the Chelyabinsk (City) Forest with adjacent territories 151 species were recorded from 1987 to 2022, of which 74 are reliably assumed to be nesting. In 2017–2022 the dominants in the nesting period were Chaffinch and the Wood Warbler, the group of subdominants was made up of the Great Tit, the Willow Tit and the European Pied Flycatcher. Transformation of the ecosystem of the Chelyabinsk forest from the 1980s to the 2010s led to the disappearance of Black Grouse, Eurasian Nightjar, Golden Eagle, Redfooted Falcon, and in adjacent territories – Common Moorhen, Eurasian Oystercatcher, Grey Partridge, Common Quail, Short-eared Owl. Under the influence of recreational activities, there was a reduction in the number and abundance of ground-nesting species: the Yellowhammer has disappeared; the Tree Pipit is not numerous and comprises up only 2% of the total bird population. A number of nesting species (Northern Goshawk, Ural Owl, Eurasian Bullfinch, Chaffinch) showed ethological adaptations indicating synurbization. In the less anthropogenically disturbed Kashtak Forest for the period 2018–2022 more breeding and presumably nesting species were found (81), including urbophobic species (Common Buzzard, Black Grouse, Western Capercaillie); the total list of birds was 101 species. During the nesting period, the Chaffinch, the Wood Warbler and the Tree Pipit dominated, the group of subdominants included the Great Tit, the European Pied Flycatcher and the Common Redstart.

Climate change will affect the way biodiversity influences the stability of plant communities. Although biodiversity, associated species asynchrony, and species stability could enhance community stability, the understanding of potential nonlinear shifts in the biodiversity–stability relationship across a wide range of aridity (measured as the aridity index, the precipitation/potential evapotranspiration ratio) gradients and the underlying mechanisms remain limited. Using an 8‐year dataset from 687 sites in Mongolia, which included 5496 records of vegetation and productivity, we found that the temporal stability of plant communities decreased more rapidly in more arid areas than in less arid areas. The result suggests that future aridification across terrestrial ecosystems may adversely affect community stability. Additionally, we identified nonlinear shifts in the effects of species richness and species synchrony on temporal community stability along the aridity gradient. Species synchrony was a primary driver of community stability, which was consistently negatively affected by species richness while being positively affected by the synchrony between C3 and C4 species across the aridity gradient. These results highlight the crucial role of C4 species in stabilizing communities through differential responses to interannual climate variations between C3 and C4 species. Notably, species richness and the synchrony between C3 and C4 species independently regulated species synchrony, ultimately affecting community stability. We propose that maintaining plant communities with a high diversity of C3 and C4 species will be key to enhancing community stability across Mongolian grasslands. Moreover, species synchrony, species stability, species richness and the synchrony between C3 and C4 species across the aridity gradient consistently mediated the impacts of aridity on community stability. Hence, strategies aimed at promoting the maintenance of biological diversity and composition will help ecosystems adapt to climate change or mitigate its adverse effects on ecosystem stability. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, we selected four grassland plots in Altai forest area and used the field survey method of "two-valued occurrence" to obtain the occurrence data of each plant species in the plots so as to calculate the species diversity index value of the community as a whole and the species diversity index value of each plant species not present in the community and to make use of the difference between these two diversity indices to determine the role of each plant species in the overall species diversity of the community. The difference between these two diversity indices was used to investigate the role of each plant species in the overall species diversity of the community. The results show the following: (1) In the grassland of the Altai forest area in Xinjiang, Asteraceae, Poaceae, Fabaceae, Polygonaceae, and Rosaceae are the dominant families, among which the genera Puccinellia Parl, Taraxacum, Pharbitis, Lactuca, Geranium, and Alchemilla are the dominant genera. (2) The plant species with the greatest contribution to species diversity in the four grassland samples was not the first dominant species of the community, but rather the plant species whose dominance was in the second to sixth position. (3) The first dominant species was overwhelmingly dominant in the four sample plots, and it served to increase the overall diversity of the community. (4) The overall trend in the size of the role of species in diversity is unimodal, i.e., logarithmically increasing to a maximum as species dominance decreases and then exponentially or linearly decreasing and eventually converging to zero. The synthesis showed that it was not the first dominant species that played the largest role in species diversity in the different grassland communities and that the overwhelmingly dominant species reduced the species diversity of the community. [ABSTRACT FROM AUTHOR]

Biodiversity is declining at unprecedented rates worldwide due largely to land use change and abnormal disturbance events. The high species diversity and endemicity found in California's coastal sage scrub (CSS) are especially at risk from urban development and ongoing disturbance. However, several CSS plant species have disturbance adaptations which may allow them to serve as vital resources for insect pollinators when native plant diversity is threatened. Common fiddleneck (Boraginaceae; Amsinckia menziesii var. intermedia) is one of the first annual forbs to germinate in CSS and as a result, it occurs in high density patches in early spring which temporarily creates a near monoculture. Although fiddleneck is a prominent CSS plant, particularly in areas that have experienced a disturbance event, its larger ecological role is not well explored. Therefore, we monitored ten sites across a disturbance gradient for two spring seasons to assess the composition of plant-pollinator networks in fiddleneck-dominated plots. We found fiddleneck supported a diverse pollinator community with 68% of recorded taxa visiting fiddleneck. The plants most frequently visited included two native annual forbs (common fiddleneck and Phacelia distans) and two invasive annual forbs (Erodium cicutarium and Brassica tournefortii). Increased mean precipitation resulted in increased plant abundance but decreased native pollinator diversity. Additionally, plant-pollinator networks changed over time; the number of links per species increased throughout the season but did not differ among disturbance types. Despite the numerical dominance of fiddleneck, CSS supported a diversity of pollinator taxa and exhibited complex plant-pollinator networks across the disturbance gradient. [ABSTRACT FROM AUTHOR]

Parthenium hysterophorus L. has become a weed of global concern owing to its fast expansion and invasive character. In order to study the status of this noxious weed and its impact on floristic diversity in Dhauladhar foothills, the study was conducted during the year 2021–2022 in culturable wastelands of Dhauladhar ranges in Kangra district of Himachal Pradesh, India. The impact of Parthenium hysterophorus L. on associated species at different altitudes and aspects was observed. Our observations depicted that Parthenium hysterophorus L. has been growing more vigorously in the northern aspect than the southern aspect with the density of 37.78 m−2 and 21.62 m−2, respectively. The highest density of this noxious weed was recorded in the altitudinal range of 600–1200 m (34.32 m−2) while it was not observed beyond 1805 m above sea level. The invasion of Parthenium hysterophorus L. significantly affected the plant density of other species. The descending order of the species as per dominance was observed as Cynodon dactylon, Trifolium repens, Oxalis latifolia, Parthenium hysterophorus L., and Ageratum houstonianum. The average number of species and species density were observed more in non-invaded sites (9.35 and 27.67 m−2) than in invaded sites (7.10 and 20.60 m−2). Species abundance and plant cover were observed more in non-invaded sites (28.73 and 657.90 m2 ha−1) than in invaded sites (22.70 and 322.30 m2 ha−1). Species diversity, richness, and evenness were reported to decline in invaded sites (1.56, 0.95, and 0.81, respectively) with respect to the non-invaded sites (1.94, 1.16, and 0.88, respectively). The study highlights the significant concerns associated with the invasive weed within the plant communities. Understanding its invasive status holds considerable implications for local afforestation initiatives, forest management strategies, and conservation policies. Furthermore, this investigation lays a foundational groundwork for implementing effective measures to get rid of this alien weed. [ABSTRACT FROM AUTHOR]

Comprehensive vegetation surveys are crucial for species selection and layout during the restoration of degraded island ecosystems. However, due to the poor accessibility of uninhabited islands, traditional quadrat surveys are time-consuming and labor-intensive, and it is challenging to fully identify the specific species and their spatial distributions. With miniaturized sensors and strong accessibility, high spatial and temporal resolution, Unmanned Aerial Vehicles (UAVs) have been extensively implemented for vegetation surveys. By collecting UAVs multispectral images and conducting field quadrat surveys on Anyu Island, we employ four machine learning models, namely Gradient Boosting Decision Tree (GBDT), Support Vector Machine (SVM), Random Forest (RF) and Multiple Classifier Systems (MCS). We aim to identify the dominant species and analyze their spatial distributions according to spectral characteristics, vegetation index, topographic factors, texture features, and canopy heights. The results indicate that SVM model achieves the highest (88.55%) overall accuracy (OA) (kappa coefficient = 0.87), while MCS model does not significantly improve it as expected. Acacia confusa has the highest OA among 7 dominant species, reaching 97.67%. Besides the spectral characteristics, the inclusion of topographic factors and texture features in the SVM model can significantly improve the OA of dominant species. By contrast, the vegetation index, particularly the canopy height even reduces it. The dominant species exhibit significant zonal distributions with distance from the coastline on the Anyu Island (p < 0.001). Our study provides an effective and universal path to identify and map the dominant species and is helpful to manage and restore the degraded vegetation on uninhabited islands. [ABSTRACT FROM AUTHOR]

Question: Granivorous ants may affect plants negatively by diminishing their numbers, or positively by dispersing seeds, reducing aggregation and thus competition. We assessed whether, and how, ants affect plant populations and community diversity. Location: Semi‐arid grassland in southern Mexico. Methods: Over 5 years, using ant exclosures, we compared plant diversity in plots where ants were present or not using Hill numbers. Furthermore, we determined whether the effects of ants on plant species depend on the relative dominance or rarity of plants. We tested whether ants cause greater reductions in the abundance of the plant species they prefer most. We also determined whether plant species whose aggregation was reduced by ants increased in numbers. Results: Six plant species increased their numbers when ants were present, and four experienced reductions. Ants reduced richness, although evidence was inconclusive; however, they clearly increased dominant species diversity (2D). Although the overall effect that ants exerted on plant species did not depend on their dominance or rarity, four of the five most abundant species were favored by ants. Ants' preferences did not determine their effect on species' abundance. The species that benefited from ants were those whose spatial aggregation increased when exposed to ants. Conclusions: Ants do not maintain richness, but instead may reduce it by favoring a few dominant species. The lack of a relationship between ants' preferences and their effect on plant populations may arise from a mixture of positive and negative effects on the preferred seeds. Ants may increase aggregation by enhancing seedling performance near their nests, where conditions may be improved, and by dispersing seeds into these areas. This is in line with our finding that common species are favored by ants, because, at our study site, they are more likely to be dispersed. [ABSTRACT FROM AUTHOR]

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This paper aims to understand the influence of tourism on ecological diversity and resource structure of forest parks in order to provide guidance for the development and utilization of forest parks. Taking a forest park in China as an example, the degree of tourism impact was divided into three types, and sample plots were arranged. Plant and soil data were collected to analyze vegetation diversity, soil physicochemical properties, enzyme activities, and microbial diversity. In the highly impacted plots (HI), the importance values of dominant species increased, and its Margalef richness index and Shannon-Wiener diversity index values were significantly different from those of the moderately impacted plots (MI) and the lowly impacted plots (LI) (p < 0.05). In HI, the soil bulk density was 1.58 ± 0.15 g/cm3, the moisture content was 6.87 ± 0.56%, the pH value was 8.26 ± 0.15, the electrical conductivity was 93.29 ± 6.12 µs/cm2, and the content of organic matter was 12.77 ± 0.78 g/kg. The various enzyme activities were lower in HI, which were significantly different from MI and LI. The bacterial, fungal, and actinomycete communities of HI were less similar to those of LI. Under the influence of tourism, the vegetation diversity of the forest park decreased, soil properties changed, and microbial diversity decreased, which was not conducive to ecological stability. Therefore, it is necessary to reduce the intensity of tourism and protect the environment in the park. [ABSTRACT FROM AUTHOR]

This study investigated the species, density, biomass and physicochemical factors of benthic macroinvertebrates in Hongze Lake from 2016 to 2020. Redundancy analysis (RDA) was used to analyze the relationship between physicochemical parameters and the community structure of macroinvertebrates. Macroinvertebrate-based indices were used to evaluate the water quality conditions in Hongze Lake. The results showed that a total of 50 benthic species (10 annelids, 21 arthropods and 19 mollusks) were collected. The community structure of benthic macroinvertebrates varied in time and space. The dominant species were Limnodrilus hoffmeisteri (L.hoffmeisteri), Corbicula fluminea (C.fluminea), Nephtys oligobranchia (N.oligobranchia). In 2016, arthropods such as Grandidierella sp. were the dominant species of benthos in Hongze Lake while annelids and mollusks dominated from 2017 to 2020, such as L.hoffmeisteri, N.oligobranchia, C.fluminea. The benthic fauna of Chengzi Lake and Lihewa District were relatively abundant and showed slight variation, while the benthic macroinvertebrates of the Crossing the water area were few and varied greatly. RDA showed that changes in benthic macroinvertebrate structure were significantly correlated with dissolved oxygen (DO), Pondus Hydrogenii (pH) and transparency (SD). The Shannon Wiener, Pielou, and Margalef indices indicate that Hongze Lake is currently in a moderately polluted state. Future studies should focus on the combined effects of various physicochemical indicators and other environmental factors on benthic communities. [ABSTRACT FROM AUTHOR]

Integrating cover plants with crops can be prioritized as a non-chemical method for weed control, promoting environmental protection and sustainable agriculture in saffron fields. This study aimed to examine the impact of cover crops on weed density and biomass in a saffron field using a randomized complete block design with three replications conducted in Neka in 2022. The experimental treatments applied in the saffron farm included: cover crop planting of Persian clover (Trifolium resupinatum), barley (Hordeum vulgare), fenugreek (Trigonella foenum - graecum L.), rapeseed (Brassica napus), treatment of no weed control with cover crop (control 1) and weeds control with no cover crop (control 2). The measured traits encompassed the density and biomass of both broad-leaved and narrow-leaved weeds, the predominant weed density within the field, the Shannon-Wiener species diversity index, and performance indicators of saffron corms. These indicators included the number of daughter corms, total daughter corm yield, average daughter corm weight, average corm diameter, and corm yield across various weight groups per square meter. The results showed that barley cover crop cultivation treatment has the lowest density and biomass of broad-leaved and narrow-leaved weeds among the treatments, so its cultivation caused a decrement of 96 and 88% of the biomass of broad-leaved and narrow-leaved weeds, respectively. In addition, among cover crops, the highest species diversity related to canola and the lowest one related to barley are 0.93 and 0.43, respectively. With the comparison among the cover crops, the highest total yield of daughter corm belonged to canola, clover, fenugreek and then barley were 1273.9, 1243, 1234.8 and 1175.2 g/m2 , and the highest total corm yield, average corm weight and corm yield above 8 g was obtained with canola cover crop cultivation, which showed an increase of 6, 79 and 14%, respectively, compared to the control with no weeding. Overall, while the weeding treatment and saffron corm yield indicators demonstrated superiority compared to other treatments, it's essential to note that planting cover plants not only enhances system stability and fertility in the long term but also offers higher economic advantages, ultimately benefiting the farmer. [ABSTRACT FROM AUTHOR]

Abstract Understanding how plant functional traits respond to mining activities and impact metal(loid)s accumulation in dominant species is crucial for exploring the driving mechanisms behind plant community succession and predicting the ecological restoration potential of these plants. In this study, we investigated four dominant herbaceous species (Artemisia argyi, Miscanthus sinensis, Ficus tikoua, and Ageratina adenophora) growing on antimony (Sb) mining sites (MS) with high Sb and arsenic (As) levels, as well as non‐mining sites (NMS). The aim was to analyze the variations in functional traits and their contribution to Sb and As concentrations in plants. Our results indicate that mining activities enhanced soil nitrogen (N) limitation and phosphorus (P) enrichment, while significantly reducing the plant height of three species, except for F. tikoua. The four species absorbed more calcium (Ca) to ensure higher tolerance to Sb and As levels, which is related to the activation of Ca signaling pathways and defense mechanisms. Furthermore, plant Sb and As concentrations were dependent on soil metal(loid) levels and plant element stoichiometry. Overall, these findings highlight the regulatory role of plant element traits in metal(loid) concentrations, warranting widespread attention and further study in the future.

Abstract Blackwater constitutes a primary component of environmental pollution posing serious risk to human health; however, reusing the nutrients found in blackwater diminishes the associated pollution and promotes resource recycling. Conventional green-wall systems are not suitable for in situ treatment of high-concentration wastewater. Thereby, a novel multi-unit green-wall system with six independent treatment units was designed to achieve a cost-effective and eco-friendly in situ treatment of blackwater with high organic load. Zeolite carriers were selected for the matrix with carrier depth of 14.5 cm, ivy and chlorophytum were selected as the greening plants. Various pollutants were rapidly reduced at the initial stage and the concentration of the pollutants decreased as the number of treatment units increased. Overall, the green-wall system was more effective in removing COD and NH4 +–N with the removal rates of 98.5% and 98%, which may be due to the good buffering capacity of the media and the roles of Firmicutes and Bacteroidetes in COD degradation and ammoniated nitrification reactions. In addition, the maximum TP and TN removal rates were observed with a value of 85% and 42%, respectively. Consequently, the novel multi-unit green-wall system is an effective method for in situ blackwater reuse. Graphical Abstract

To describe the species composition of fish larvae and juveniles in the Nanji Islands, monthly collection was conducted at 12 stations around the Nanji Islands from March 2023 to February 2024 by using horizontal tow at the surface layer. The fish larvae and juveniles were collected by a larva net (1.3 m mouth diameter, 0.5 mm mesh aperture). A total of 6446 fish larvae and juveniles were collected, belonging to 59 species and 54 genera in 11 families. Most of them were preflexion larvae (93.31%). Gobiidae, with eight species, was the most diverse family. Based on the index of relative importance (IRI) result, the dominant species was Sebastiscus marmoratus (Cuvier, 1829), accounting for 84.52% of the total number of samples collected. The common species were Stolephorus commersonii Lacepède, 1803; Omobranchus elegans (Steindachner, 1876); Nibea albiflora (Richardson, 1846); Parablennius yatabei (Jordan & Snyder, 1900); Lateolabrax maculatus (McClelland, 1844); and Odontamblyopus lacepediiand (Temminck & Schlegel, 1845). Other species were all rare species. The highest species number was in September (18 species), and the highest density was in December. Only one fish larva was collected in April. Pielou’s evenness index was highest in November, while Margalef’s richness index and Shannon–Wiener diversity were highest in September. The result of cluster analysis showed that the 11 months (except April) could be divided into four groups. The species number, density, and three diversity indexes showed no significant correlation with temperature and salinity.

Dominant species are crucial in regulating the structure and productivity of plant communities. Adaptation strategies to climate change vary among the dominant species of different life types. However, the responses of the ecological niches of dominant species to warming and precipitation in semi-arid grasslands and their impacts on community structure and function are unknown. This study involved conducting a long-term experimental simulation of warming and increased precipitation on grasslands in Inner Mongolia and studying population dynamics, ecological niches, and their responses to the structure and function of the community species of two dominant plants, L. chinensis (perennial rhizome grass) and S. krylovii (perennial clumped grass). The results show that the niche width of L. chinensis increased and S. krylovii decreased under warming and increased precipitation conditions. The overlap of L. chinensis and S. krylovii decreased under the same conditions. The niche widths of L. chinensis and S. krylovii were 1.22 for the control (C), 1.19 and 1.04 under warming (W) conditions, 1.27 and 0.97 under warming plus precipitation (WP) conditions, and 1.27 and 1.24 under the conditions of precipitation addition (P). The niche overlap of L. chinensis and S. krylovii were 0.72 in C, 0.69 in W, 0.68 in WP, and 0.82 in P. The biomass share and importance value of L. chinensis increased, and those of S. krylovii decreased in response to warming and precipitation. The effects of warming on species diversity and community stability are primarily influenced by the effects on the niche breadth of S. krylovii. Combined with our previous study, L. chinensis will offer more resources in communities in warmer and wetter steppe climates in the future. However, this is not conducive to community diversity.

Bruchophagus is a serious pest that damages the seeds of Astragalus, causing significant negative effects on the yield and quality of Astragalus seeds. In order to clarify the characteristics and mechanism by which Bruchophagus damages in different planting areas of Shanxi province, in this study, the species, damage situation, and field occurrence rule of Bruchophagus in different regions of Shanxi province from 2021 to 2022 were studied. The results suggested that the Bruchophagus species in Shanxi province included six species: B. huonchili, B. mongolicus, B. ciriventrious, B. beijingensis, B. pseudobeijingensis, and Habrocytus huonchei. However, the dominant species differed in different planting areas. B. huonchili was dominant in Taigu district and Hunyuan county, while H. huonchei was dominant in Wuzhai county. Moreover, the infestation rates of pods and seeds of Astragalus varied among different planting areas, with Hunyuan county showing the highest rates of 65.93% and 41.36%, respectively. Additionally, field investigation found that there were differences in the occurrence period of Bruchophagus among different planting areas. The occurrence period in Taigu district, Jinzhong city, was earlier than in Wuzhai county and Hunyuan county, indicating a delayed occurrence as latitude increases. In Shanxi province, the Bruchophagus occurred from mid-May or late-May to early-August or mid-August, with variations in the peak occurrence period among different regions. [ABSTRACT FROM AUTHOR]

Based on the trawl survey data along the Bering Sea slope in 2002, 2004, 2008, 2010, 2012 and 2016, all the cephalopods species were selected in this study. With the cephalopods data, we analyzed the cephalopods community composition, determined the dominant species and their spatial distribution in relation to environmental factors in the Bering Sea slope based on the generalized additive model, and quantified the distribution of cephalopods abundance （indicated by catch per unit effort, CPUE） in latitude and longitude. The diversity of cephalopods community was further evaluated according to the ecological methods. The results showed that a total of 20 cephalopods species were identified belonging to 3 orders, 9 families and 15 genera. The highest CPUE of the cephalopod species in latitude was 0. 78 kg/km² at 55oN. The CPUE in longitude fluctuated between 0. 3 and 0. 7 kg/km² except that the value exceeded 1. 0 kg/km² around 166. 5oW, 171. 5oW and 177. 5oW. The dominant cephalopod species in the survey area were Berryteuthis magister, Enteroctopus dofleini, Opisthoteuthis californiana, Benthoctopus leioderma, and Rossia pacifica. Among them, there were significant spatial differences in the distribution of dominant species. In the stations east of 172oW, species were mainly dominant species, and there were few other species. In the stations west of 172oW, the CPUE of other cephalopods was relatively high except for Berryteuthis magister and Enteroctopus dofleini. GAM model analysis showed that longitude, latitude, bottom depth, bottom temperature and surface temperature were important factors affecting the CPUE of the most dominant species. The results of cluster analysis showed that there were two main clusters in different regions, and great differences were found in the community diversity index among different clusters. [ABSTRACT FROM AUTHOR]

The estuarine areas are under frequent influence from freshwater intrusion and ocean currents, in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in water. Therefore, understanding the relationships between zooplankton and environmental factors help us know the water quality. To achieve co-existence with species in similar ecological group or habit, they could inevitably alter themselves to fit the ecology and adjust the function according to the competitive exclusion in ecological theory. However, information of the co-existence of dominant species in the Changjiang (Yangtze) River estuary (CRE) and adjacent waters remains scarce. We explored the relationships between dominant zooplankton and environmental factors in the study region in spring-summer from 2016 to 2020, involving particularly the composition of dominant species, ecological groups, their relationships with environmental factors, and co-existence of important species, using the non-multidimensional scale analysis (nMDS) method and redundancy analysis. Results show that Labidocera euchaeta and Tortanus vermiculus were dominant species in the study scope. The turnover rate of dominant zooplankton was greater (>50%) in spring while the species number was higher in summer. The dominant species were estuarine, offshore, and eurytopic based on the adaptation to salinity. In spring, the ecological groups were dominated by estuarine species, while in summer by estuarine and offshore species. In addition, the nMDS showed that the dominant species in the same ecological group were more dispersed and not prominently clustered; the dominant species were staggered among different ecological groups. The temperature, salinity, pH, dissolved oxygen, and chlorophyll a were the main environmental factors on the distribution of the dominant species in spring, while in summer were dissolved oxygen, temperature, salinity, and pH. The domination of medusae of Nemopsis bachei and Pleurobrachia globosa in zooplankton community in spring, and the continuous decrease in abundance of L. euchaeta reflected the effects of local climate change. The temperature and salinity changes in different years and the subsequent response of zooplankton reflected the influence of freshwater intrusion and/or ocean currents. Zooplankton in similar ecological habits exhibited the competitive exclusion in terms of co-existence. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Maximizing the effectiveness of natural pest control requires a detailed understanding of how service delivery is affected by natural enemy community diversity and composition. Many studies have investigated the effects of natural enemy abundance and species richness on pest control. Studies examining the effects of evenness and species identity are fewer and have produced inconsistent results. Here we test the effects of arthropod predator community evenness and species identity on natural pest control by exposing aphid (Sitobion avenae) colonies in experimental cages to arthropod predator communities that had the same abundance and species richness but differed in evenness and dominant species. RESULTS: We found that the identity of the most dominant species in the arthropod predator community predominantly drove the pest control efficiency. However, additional to the effects of species identity, we also found a causal positive relationship between the evenness of arthropod predator communities and the suppression of pest growth. CONCLUSION: Our results provide support for the hypothesis that ecosystem service provision is generally a function of the abundance and efficiency of the most dominant species of the service‐providing groups. This could partly explain why management practices aiming at promoting abundance of natural enemies often have mixed effects on pest control. Our results also demonstrate that diversity components such as evenness have important additional effects. However, in real‐world ecosystems these effects may be obscured because evenness is generally confounded with abundance or species richness in natural enemy predator communities. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background and aims: It is unclear how atmospheric nitrogen (N) deposition influences CO2 release from grassland by affecting heterotrophic respiration of bulk and rhizosphere soils and how the heterotrophic rhizosphere respiration of different grass species responds to N deposition. Methods: In this study, we investigated the effects of N addition on heterotrophic respiration of bulk and rhizosphere soils associated with the dominant species (Bothriochloa ischaemum) and subdominant species (Artemisia sacrorum and Stipa capillata) in the grassland treated with N fertilizer (0,3,9 g N m−2 y−1) for eight years. Results: Low-N addition significantly increased cumulative CO2-C emissions of bulk soil by 22.91% and rhizosphere soil of A. sacrorum by 72.26%, while high-N addition significantly increased that of rhizosphere soil of (A) sacrorum by 37.38% and S. capillata by 13.71%. There was no clear response to N addition for (B) ischaemum. Heterotrophic rhizosphere respiration of B. ischaemum was most strongly related to stable-C-degrading functional genes, whereas that of A. sacrorum and S. capillata was most strongly related to labile-C-degrading functional genes. C-degrading functional genes in rhizosphere soil were significantly related to root morphological characteristics, especially specific root length, specific root surface area, and root average diameter rather than root exudation rates. Conclusion: The present study revealed that N addition could affect heterotrophic soil respiration by changing labile-C and stable-C degrading functional genes, which in the rhizosphere of different plant species were regulated by their root functional traits. [ABSTRACT FROM AUTHOR]

Dominance of neotropical tree communities by a few species is widely documented, but dominant trees show a variety of distributional patterns still poorly understood. Here, we used 503 forest inventory plots (93,719 individuals ≥2.5 cm diameter, 2609 species) to explore the relationships between local abundance, regional frequency and spatial aggregation of dominant species in four main habitat types in western Amazonia. Although the abundance‐occupancy relationship is positive for the full dataset, we found that among dominant Amazonian tree species, there is a strong negative relationship between local abundance and regional frequency and/or spatial aggregation across habitat types. Our findings suggest an ecological trade‐off whereby dominant species can be locally abundant (local dominants) or regionally widespread (widespread dominants), but rarely both (oligarchs). Given the importance of dominant species as drivers of diversity and ecosystem functioning, unravelling different dominance patterns is a research priority to direct conservation efforts in Amazonian forests. [ABSTRACT FROM AUTHOR]

Forest management planning often relies on Airborne Laser Scanning (ALS)-based Forest Management Inventories (FMIs) for sustainable and efficient decision-making. Employing the area-based (ABA) approach, these inventories estimate forest characteristics for grid cell areas (pixels), which are then usually summarized at the stand level. Using the ALS-based high-resolution Norwegian Forest Resource Maps (16 m x 16 m pixel resolution) alongside with stand-level growth and yield models, this study explores the impact of three levels of pixel aggregation (standlevel, stand-level with species strata, and pixel-level) on projected stand development. The results indicate significant differences in the projected outputs based on the aggregation level. Notably, the most substantial difference in estimated volume occurred between stand-level and pixel-level aggregation, ranging from -301 to +253 m³•ha-1 for single stands. The differences were, on average, higher for broadleaves than for spruce and pine dominated stands, and for mixed stands and stands with higher variability than for pure and homogenous stands. In conclusion, this research underscores the critical role of input data resolution in forest planning and management, emphasizing the need for improved data collection practices to ensure sustainable forest management. [ABSTRACT FROM AUTHOR]

Diversified plant species in homestead areas play an important role to ensure the food and nutritional security of rural communities. An exploratory survey and field observation was carried out at Sadar upazila of Rangamati district in Bangladesh to identify the existing plant biodiversity in the homestead areas of six unions along with municipal area of Rangamati Sadar upazila. A total of 120 households were randomly selected for collecting data using face-to-face interviews from July to September 2020. A total of 163 plant species were identified at different homesteads of the study area. Among different categories of plant species, 13 (7.98%) timber, 32 (19.63%) fruits, 19 (11.66%) medicinal species, 31 (19.02%) different vegetable species, 56 (34.36%) different flowering and ornamental species, 08 (4.91%) spices and condiments and 04 (2.45%) other plant species were recorded. The front yard was dominated by most of the plant species whereas the kitchen side was dominated by vegetables. The highest diversity was found in vegetables (H'= 0.96) followed by medicinal plant and fruit species (H'= 0.83), timber, and flower and ornamental species (H'= 0.82). A moderate diversity was found at the back side (H'=0.69) followed by the boundary side (H'=0.68), front yard (H'=0.65) and, approach road (H'=0.60). The study concludes that homestead agroforestry is a unique area for maintaining both plant diversity and productivity which could be a good option to meet up the demand of food and nutrition of the people in hilly areas. [ABSTRACT FROM AUTHOR]

The same ecological niche cannot support two species in a similar habitat. To avoid negative interactions, species tend to adapt to several biological phenomena and resource utilization patterns. The temperature also has an effect on the presence and distribution of various insect communities in any ecosystem. Butterfly species utilize similar habitat types or even microhabitats, with their other co-species and share the same daytime if the resources are plentiful. However, they follow a certain ecological temporal distribution pattern by using different intervals in the same time frame to avoid interspecific competition. The present study aimed to examine the occurrence of common and uncommon kinds of butterflies through out the day in a small habitat at Jolkol, Serampore, West Bengal, using the Modified Pollard Walk Method and the brief study period evaluated any butterfly species' shifting patterns to determine how best to use available resources during the period. The study revealed a pattern in the presence of different butterfly species throughout time, enabling cospecies to share resources from the same environment. [ABSTRACT FROM AUTHOR]