Arid and semi-arid vegetation is characterized by plant patches of different sizes, and plant cover is determined by patch size (PS) and number of patches (NP). However, it is still unclear how PS and NP contribute to the restoration of degraded grasslands through grazing exclusion (GE). Transect lines were sampled in six alpine steppe communities in Tibet in 2017 and 2018. Both PS and NP were assessed and compared between inside and outside grazing exclosures. Our results showed that grazing exclosures increased the mean size but decreased the total number of plant patches. This pattern of change was common to other species and could not be attributed to a shift in community composition. The results suggest that the recovery of the degraded alpine steppe is being driven by PS at the expense of NP. By promoting the expansion of the larger patches while excluding the smaller ones, GE led to an aggregating pattern with a higher proportion of bare ground, potentially reducing primary productivity.

Landscape structure plays a key role in mediating a variety of ecological processes affecting biodiversity patterns, however its precise effects and the mechanisms underpinning them remain unclear. While the effects of landscape structure have been extensively investigated both empirically, and theoretically from a metapopulation perspective, the effects of spatial structure at the landscape scale remain poorly explored from a metacommunity perspective. Here, we attempt to address this gap using a spatially explicit, individual-based metacommunity model to explore the effects of landscape compositional heterogeneity and per se spatial configuration on diversity at the landscape and patch level via their influence on long term community assembly processes. Our model simulates communities composed of lineages of annual, asexual organisms living, reproducing, dispersing, and competing within grid-based, fractal landscapes which vary in their magnitude of spatial environmental heterogeneity and in their degree of spatial environmental autocorrelation. Communities are additionally subject to temporal environmental fluctuation and external immigration, allowing for turnover in community composition. We found that compositional heterogeneity and spatial autocorrelation had differing effects on richness and diversity and the landscape and patch scales. We also note a slight negative effect of compositional heterogeneity on median total landscape population size. Landscape level diversity was driven by community dissimilarity at the patch level and increased with greater heterogeneity, while landscape richness was largely the result of short-term accumulation of immigrants and decreased with greater compositional heterogeneity. Both richness and diversity decreased in variance with greater compositional heterogeneity, indicating a reduction in community turnover over time. Patch-level richness and diversity patterns appeared to be driven by overall landscape richness and local mass effects, resulting in maximum patch level richness and diversity at moderate levels of compositional heterogeneity and high spatial autocorrelation.

Understanding how ecological and environmental changes, anthropogenic activities, and climate have driven and will direct animals’ development and predicting their prospective distribution profiles in the Quaternary are essential to making a tangible conservation strategy. Macaques (Macaca) distributed in mainland East Asia provide an ideal research model for such an effort. We reconstruct macaques’ geographic distribution profiles during the Quaternary, from the last inter-glaciation (LIG, 120,000 - 140,000 years BP), the Last Glacial Maximum (LGM, 22,000 years BP), and the present (1970-2000) – based on which we deduce their perspective distribution in the 2050s. The results show their suitable habitats during LIG and LGM were mainly in Southwest, Central, and Coastal China. A noticeable distribution reduction started in LIG and persisted until the current (1970-2000). Their distribution centroid would shift northward to mountainous regions, mainly in Southwest China, where more migration corridors would be reserved for their future development. Also, the results indicate that China’s Protected Area currently does not cover more than 87% of macaques’ habitats, a dismal situation for their conservation. Finally, this study proclaims that the conservation priority of the macaques in the years to come should focus on Southwest China – their future refuge region in Quaternary.

Aim High alpine regions are threatened but understudied ecosystems that harbor diverse endemic species, making them an important biome for testing the role of environmental factors in driving functional trait-mediated community assembly processes. We tested the hypothesis that plant-soil feedbacks along a climatic and elevation gradient influence plant community assembly through shifts in habitat suitability, which drive plant functional, phylogenetic, and spectral diversity. Location In a high mountain system (2400-3500 m) of Región Metropolitana in the Chilean Andes (33°S, 70°W). Methods We surveyed vegetation and spectroscopic reflectance (400-2400 nm) to quantify taxonomic, phylogenetic, functional, and spectral diversity at five sites from 2400 m to 3500 m elevation. We characterized soil attributes and processes by measuring water content, carbon and nitrogen, and net nitrogen mineralization rates. Results At high elevation, colder temperatures reduced available soil nitrogen, while at warmer, lower elevations, soil moisture was lower. Metrics of taxonomic, functional, and spectral alpha diversity peaked at mid-elevations, while phylogenetic species richness was highest at low elevation. Leaf nitrogen increased with elevation at the community level and within individual species, consistent with global patterns of increasing leaf nitrogen with colder temperatures. Main conclusions The increase in leaf nitrogen, coupled with shifts in taxonomic and functional diversity associated with turnover in lineages, indicate that the ability to acquire and retain nitrogen in colder temperatures may be important in plant community assembly in this range. Such environmental filters have important implications for forecasting shifts in alpine plant communities under a warming climate.

1. Fine root distribution influences the potential for resource acquisition in soil profiles, which defines how plants interact with local soil environments; however, a deep understanding of how fine root vertical distribution varies with soil structural variations and across plant ages is lacking. 2. We subjected four xerophytic species native to an arid valley of China, Artemisia vestita, Bauhinia brachycarpa, Sophora davidii, and Cotinus szechuanensis, to increasing rock fragment content (RFC) treatments (0%, 25%, 50%, and 75%, v v-1) in an arid environment and measured fine root vertical profiles over four years of growth. 3. Fine root depth and biomass of woody species increased with increasing RFC, but the extent of increase declined with plant age. Increasing RFC also increased the degree of interannual decreases in fine root diameter. The limited supply of soil resources in coarse soils explained the increases in rooting depth and variations in the pattern of fine root profiles across RFC. Fine root depth and biomass of the subshrub species (A. vestita) in soil profiles decreased with the increase in RFC and plant age, showing an opposite pattern from the other three woody species. 4. Within species, the annual increase in fine root biomass varied with RFC, which led to large interannual differences in the patterns of fine root profiles. Capacity of younger or subshrub plants to cope with soil environmental changes were greater than the older or shrub plants. These results provide insights into the limitations of soil resources in dry and rocky environments, and have management implications for degraded agroforest ecosystem.

In the Central Himalayas, where environmental conditions vary greatly, understanding the biophysical limitations on forest carbon is crucial for accurately determining the region’s forest carbon stocks. This study investigates the role of climate and disturbance on the spatial variation of two key forest carbon pools: aboveground carbon (AGC) and soil organic carbon (SOC). Using field-observed plot-level carbon pool estimates from Nepal’s national forest inventory and structural equation modeling, we explore the relationship between forest carbon stocks and proxies of environmental constraints. The forest AGC and SOC models explained 25 % and 59 % of the observed spatial variation in forest AGC and SOC, respectively. The climatic availability of water and energy in broad-scale gradients combined with the fine-scale gradients of terrain and disturbance intensity were found to influence forest carbon stocks, but the sign and strength of the statistical relationships differ for forest AGC and SOC. While AGC showed a negative relationship to disturbance, SOC was impacted by the availability of climatic energy. Disturbances such as selective logging and firewood collection result in immediate forest carbon loss, while soil carbon changes take longer to respond. The lower decomposition rates in the high-elevation region, due to lower temperatures, preserve organic matter and contribute to the high SOC stocks observed there. These results have important implications for forest carbon management and conservation in the Central Himalayas.

The consequences of biological invasions and habitat degradation for native biodiversity depend on how species cope with the individual and synergetic challenges these processes present. To assess the impact of anthropogenic land-use on the food web architecture of an invaded community, we examine the diets of nine native and two highly invasive mammal species at different trophic levels, inhabiting different land-uses across six biogeographic regions in Tasmania, Australia. We use two complementary methods, environmental DNA metabarcoding analysis (eDNA) of faeces and stable isotope analysis (SIA) of nitrogen (N) and carbon (C) in whole blood, to account for the high inter-individual and temporal variability in animal diets. eDNA showed regionalisation in the diet of smaller species, with land-use further defining dietary taxa within each region. SIA revealed that bioregion and land-use influence the δ13C values of all carnivore species and omnivores, whereas the δ15N values of these species are influenced only by land-use and not bioregion. Including multiple species showed that native rats are changing their diet in response to the presence of invasive rats, an impact that would have been otherwise attributed to land-use. Our findings demonstrate that human activities and invasive species are molding the diets of invaded communities raising questions about the potential impacts that dietary modifications will have on the life-history traits and the evolutionary consequences these modifications might have on the survival of native species. This highlights the urgency to include human activities in ecological studies and the importance of targeting multispecies assemblages to gain a better understanding of synergetic impacts on native biodiversity.

Evidence for spatially varying selection and adaptive variation can provide insight into a species’ ability to adapt to different environments. However, despite recent advances in genomics, it remains difficult to detect footprints of spatially varying selection in natural populations. Here we analysed ddRAD sequencing data (21,892 SNPs) in conjunction with geographic climate variation to search for signatures of adaptive differentiation in twelve populations of the bank vole (Myodes/Clethrionomys glareolus) distributed across Europe. To identify the loci subject to spatially varying selection and associated with climate variation, we applied multiple genotype-environment association (GEA) methods, two univariate and one multivariate, and controlled for the effect of population structure. In total, we identified 213 candidate adaptive loci, 74 of which were located within genes. In particular, we identified signatures of selection in candidate genes with functions related to lipid metabolism and the immune system. Using the results of redundancy analysis (RDA), we demonstrated that population history and climate have joint effects on the genetic variation in the pan-European metapopulation. Furthermore, by examining only candidate loci, we found that annual mean temperature is an important factor shaping adaptive genetic variation in the bank vole. By combining landscape genomic approaches, our study sheds light on genome-wide adaptive differentiation and the spatial distribution of variants underlying adaptive variation in bank voles that are influenced by local climate.

Increasing studies have shown the importance of intraspecific trait variation (ITV) on the ecological process. However, the patterns and sources of ITV are still unclear, especially in the propagule of coastal vegetation. Here, we measured fresh weight (FW), fresh length (FL), maximum transverse diameter (TDmax), minimum transverse diameter (TDmin) and the ratio of TDmax to TDmin (RTD) of the hypocotyl (propagule) of Kandelia obovata for 66 genealogies across 26 sites. By combining multiple factors of climate, ocean and maternal tree to analyze their effects on the intraspecific trait variation of mangrove hypocotyl. The results showed that value of establishment traits (FW, FL, TDmax and TDmin which are related to mass) decreased along increasing latitudinal gradients and they were directly positively regulated by temperature. ITV of dispersal trait (RTD) was unstructured along latitudinal gradients, which was constrained by fitness tradeoff. Our findings indicate that establishment traits mainly varied between populations, whereas dispersal traits mainly varied between individuals. This study provides insights into the ITV of propagule in different functional dimensions on a broad scale and that may help integrate ITV into future analyses of mangrove protection.

1. Ice coverage duration on lakes and ponds is decreasing due to climate change, but experimentally testing the effects of decreased ice coverage on aquatic communities is challenging in field settings. 2. To assess whether we could simulate changes predicted to occur in aquatic habitats as climate change progresses including shorter ice duration, warmer temperatures, and thinner ice and associated water chemistry changes, we designed and constructed greenhouses to place over a set of ten experimental ponds, roughly 3x3m in area which slope to a maximum depth of 1m, dug into the ground at the Koffler Scientific Reserve (Ontario, Canada). Half of the wedge-shaped greenhouses were enclosed on all sides (n=5) while the other the other half were open on three sides, with only the top fitted with plastic sheeting (n=5). The open greenhouses provided a less-warmed treatment while controlling for precipitation reduction and light filtering caused by the sheeting. In November 2019 greenhouses were placed over the ponds. Snow was cleared from the greenhouses and water chemistry measures were taken once weekly through the 2019-2020 winter. 3. Ice was thinner across the winter and melted on average 10.6 days earlier in closed greenhouses compared to open greenhouses. Average winter water temperatures were also significantly higher in closed versus open greenhouses although these differences were not significant in all months. Similarly, maximum and minimum water temperatures were also higher in ponds with closed compared with open greenhouses. We successfully demonstrate a method for simulating expected changes in ice conditions as climate change progresses including decreasing ice coverage duration at levels similar to those observed in north temperate ecosystems (per century) and alpine ecosystems (per 36 years) and raising temperatures in a highly manipulatable experimental system.

Tidal flats can be found on most of the world's coastlines and are particularly vulnerable to anthropogenic disturbances. They are important transient ecosystems between terrestrial and marine ecosystems and their biodiversity provides important ecosystem services. Owed to their unique position between the terrestrial and the marine realm, strong environmental gradients of elevation, sediment composition but also food availability are prevailing. Here we investigate which environmental factors drive the spatial and temporal patterns in macrozoobenthos abundance, biomass, richness, diversity and species composition on back barrier tidal flats in the East-Frisian Wadden Sea. We found that with increasing mud content the total abundance of organisms in the sediment significantly increased, while biodiversity and biomass were not changing significantly with increasing mud content. Biomass of macrozoobenthos decreased with higher elevation towards the salt marsh. In contrast to expectations, increasing Chl a availability as a measure of primary productivity did not enhance biomass or abundance, but was associated with significantly reduced species richness. Species composition varied significantly among and within islands due to variation in sediment composition, resource availability and human-induced disturbance. In conclusion, macrozoobenthos biomass, abundance and biodiversity is interrelated in a complex way with the physical, abiotic and biotic processes in and above the sediment. Negative impacts of primary production on macrozoobenthos species richness demonstrate possible negative effects of nutrient inputs in tidal flat areas and the need for cross-boundary protection.

Invasive alien species are generally highly fertile and adaptable and can pose a severe threat to the ecological security of invaded localities. Bemisia tabaci (Gennadius) is a rapidly evolving cryptic complex. Among them, Mediterranean (MED) and Middle East–Asia Minor 1 (MEAM1) is the most invasive and widely distributed. To clarify the invasion source, population structure, and genetic differentiation drivers of whitefly populations in Xinjiang, China, we collected B. tabaci from 14 host crops in Xinjiang, China. A total of 453 sequenced cytochrome c oxidase subunit I(COI) fragments were analysed. We used common methods and parameters of genetic analysis, such as phylogenetic analysis, haplotype diversity, and nucleotide diversity, neutrality testing, and mismatch distribution chart analysis to determine the genetic structure and genetic differentiation and explore the origin of the invasion of B. tabaci populations in Xinjiang. The results have shown that global MED and MEAM1 populations are genetically differentiated, and MED has a significant geographical lineage structure at the Xinjiang and global spatial scales. This was the same for the MEAM1 population at the Xinjiang spatial scale. There have been multiple local expansions and founder effects in the MED populations. The MEAM1 population has retained a stable population size with a bottleneck effect. Based on the phylogenetic tree for MED and MEAM1, it has been demonstrated that there have been multiple points and pathways of invasion of B. tabaci and the sources in Xinjiang, China were complex. The sources of MED invasion of MED are likely to be Zhejiang, Hebei, or Shanxi. The source for MEAM1 is complex, and Zhejiang is one of the main invasion sources. This study has shown that host plant differences in open habitats, geographic isolation, and habitat differences were the driving factors for genetic differentiation of B. tabaci populations in Xinjiang, China

Landlocking is a process whereby a population of normally diadromous fish becomes limited to freshwater, potentially leading to behavioural, morphological, and genetic changes, and occasionally speciation. The study of recently landlocked populations can shed light on how populations adapt to environmental change, and how such life-history shifts affect population-genetic structure. Kōaro (Galaxias brevipinnis) is a facultatively diadromous Southern Hemisphere galaxiid fish that frequently becomes landlocked in inland lakes. This study compares seven landlocked kōaro populations to diadromous populations from main and offshore islands of New Zealand. Genotyping-by-sequencing was used to obtain genotypes at 18,813 single nucleotide polymorphism sites for each population. Analyses of population structure revealed that most landlocked populations were genetically highly distinct from one another, as well as from diadromous populations. A few particularly isolated island and lake populations were particularly strongly genetically differentiated. Landscape characteristics were measured to test whether lake elevation, size, or distance from the sea predicted genetic diversity or differentiation from diadromous kōaro. While there were no significant relationships indicating isolation-by-distance or isolation-by-environment, we detected a trend toward lower genetic diversity in lakes at higher elevations. Our findings illustrate the critical role that landlocking can play in the structure of intraspecific genetic diversity within and between populations.

The study of the eukaryotic fraction of the microbiota using a metabarcoding approach is usually hindered by the high host to eukaryotic microbiota DNA ratio in samples. Indeed, the 18S rRNA gene is very similar for both the host and its eukaryotic communities, leading to a preferential amplification of the predominant host DNA when using universal primers. Multiple approaches have been developed to reduce host DNA amplification. One method is based on elongation arrest blocking primers, oligonucleotides modified with a C3 Spacer that stops the advancement of the DNA polymerase at non-conserved regions of a target gene. In this paper, we successfully developed and tested species-specific elongation arrest blocking primers to block the Flag cichlid, Mesonauta festivus, 18S rRNA SSU. Our elongation arrest blocking primers significantly reduced the amount of host DNA amplicons by 66 %. In addition to reducing the amount of sequencing wasted, the blocking primers increased the detectability of potentially dangerous parasitic taxa in fish gut, highlighting the potential of the method for parasitic screening. For instance, we discovered a case of infection by the parasitic ciliate Nyctotherus sp. and detected the presence of a parasitic Trematode and an Amoebae. While our data support the possibility of achieving a complete inhibition of host DNA amplification using elongation arrest blocking primers, more research is still required. Still, there is a need for the development and additional testing of protocols to study the eukaryotic diversity present in fish gut, a slow-growing field of study in comparison to its prokaryotic counterpart.

We use the InVEST model and five periods of land use data from 1980 to 2020 to assess the habitat quality of the Ningxia Hui Autonomous Region in western China, which has characteristics of a typical fragile ecosystem. We further analyze the spatial and temporal characteristics of habitat quality evolution and its relationship with land use and landscape pattern indices to explore the close relationship between regional habitat quality changes and human natural resource conservation and utilization.The research results show that the overall habitat quality of Ningxia Hui Autonomous Region was stable and at a moderate level during the 40 years from 1980 to 2020; Habitat patches with low, high and very high quality occupy a larger proportion of the area, followed by very low and moderate levels. There was a significant spatial aggregation of high and low habitat quality in Ningxia, with high values usually distributed in the northern and southern areas with good natural conditions and low values distributed in areas with frequent human activities and poor natural conditions. The decrease in habitat quality in Ningxia was mainly due to the expansion of cultivated land and construction land, the increase in landscape fragmentation and the resulting decrease in connectivity. On the other hand, due to the implementation of ecological protection measures, such as the project of returning farmland to pasture and grass to forest, the quality of habitats in Ningxia increased. The conclusions of this study support the idea that the conservation of habitat quality in ecologically fragile areas should fully preserve the original natural habitats and reduce the interference of human activities. At the same time, targeted ecological protection policies should be developed to restore the areas where the habitat quality has been damaged and ultimately maintain the stability of biodiversity and ecosystems in ecologically fragile areas.

1. Passive Acoustic Monitoring is emerging as a solution for monitoring species and environmental change over large spatial and temporal scales. However, drawing rigorous conclusions based on acoustic recordings is challenging, as there is no consensus over which approaches and indices are best suited for characterizing marine acoustic environments. 2. We present an alternative to the use of ecoacoustic indices and describe the application of multiple machine learning techniques to the analysis of a large PAM dataset. We combine pre-trained acoustic classification models, dimensionality reduction, and random forest algorithms to demonstrate how machine-learned acoustic features capture different aspects of the marine environment. We processed two PAM databases and conducted 13 trials showing how acoustic features can be used to: i) discriminate between the vocalizations of marine mammals, beginning with high-level taxonomic groups, and extending to detecting differences between conspecifics belonging to distinct populations; ii) discriminating amongst different marine environments; and iii) detecting and monitoring anthropogenic and biological sound sources. 3. Acoustic features and their UMAP projections exhibited good performance in the classification of marine mammal vocalizations. Most of the taxonomic levels investigated here could be classified using the UMAP projections, apart from species that were underrepresented. Both anthropogenic (ships and airguns) and biological (humpback whales) sound sources could also be identified in field recordings. 4. We argue that acoustic feature extraction, visualization, and analysis allows the retention of most of the environmental information contained in PAM recordings, overcoming the limitations encountered when using ecoacoustics indices. Acoustic features are universal, permitting comparisons of results collected from multiple environments. Our approach can be used to simultaneously investigate the macro and micro characteristics of marine soundscapes, with a more objective method and with far less human effort.

Background and aims High-intensity grazing in Mongolian grasslands has led to the general deterioration of biodiversity and ecosystem functioning. Abundant evidence shows that grazing affects the structure and function of grassland ecosystems, especially under overgrazing. Methods We examined the effects of three grazing intensities (0, 1.92, and 3.08 sheep ha-1 a-1) on plant commu-nities, plant and soil C, N and P contents, and plant and soil C:N:P stoichiometry in a desert grassland in different years. Results Grazing did not affect plant coverage, richness, or N:P, and the plant community biomass, litter bio-mass and C:N and C:P were highest under a zero grazing intensity. Soil C:N changed with the year and grazing intensity. However, soil C:P and N:P were higher in 2018 than in 2016 and 2017. Conclusions Our study suggested that grazing promoted the flow of N between plants and the soil, especially at 3.08 sheep ha-1 a-1. Under grazing stress, plants maintained the potential for compensatory growth. Further-more, N was shown to be the limiting fertilizer component for plants growing in this area among the three grazing intensities.

The encroachment of freshwater territories by invasive species is a global issue with its associated co-existence, displacement and facilitation of native species. The blackchin tilapia, Sarotherodon melanotheron is one of the most successful biological invasive species. Data on its apparent ecological consequences on native species are rare in Nigerian inland waters. Based on stomach contents analyses, diets, feeding strategies, and dietary niche breadths of two sympatric invasive S. melanotheron and native Nile tilapia Oreochromis niloticus populations in a tropical domestic water supply were assessed for possible convergence. Both species exhibited generalist feeding strategies subsisting mostly on algae but fish eggs and larvae were conspicuous preys of S. melanotheron. Dietary niche of S. melanotheron was wider than that of O. niloticus. Dietary niche overlap was high and significant between these sympatric species. These findings imply that competitive feeding interactions-including predations on vulnerable early life stages may potentially promote invasion success of S. melanotheron in Eleiyele Reservoir.