Spatial Patterns Of Biodiversity Research Articles

Spatial patterns of biodiversity and hotspots in Chongqing Pengxi River Wetland Nature Reserve, China

The analysis of biodiversity spatial patterns and the detection of hotspots are effective ways for conservation planning and scientific management of biodiversity. Based on field investigation, historical data and literature information, we constructed the comprehensive index of biodiversity by considering habitat quality, species diversity and landscape diversity within Chongqing Pengxi River Wetland Nature Reserve. Combined with spatial autocorrelation analysis, we analyzed spatial distribution pattern and the degree of spatial autocorrelation of biodiversity in the nature reserve, identified biodiversity hotspots, and discussed the protection effectiveness of existing nature reserve for the hotspots. The results showed that the spatial pattern of biodiversity in the nature reserve tended to decrease with the increases of distance from the river and riparian zone. Areas with high value of biodiversity index were mainly concentrated in Pengxi River, Puli River, Baijiaxi Stream and alongshore areas. There was significant positive correlation in the spatial distribution of biodiversity. The spatial autocorrelation of local areas was mainly characterized by high-high aggregation and low-low aggregation. The area of biodiversity hotspots was 457 hm2, accounting for 11.1% of the total nature reserve. The core area of current nature reserve covered 51% of the hotspots and 50% of the secondary hotspots. The structure and functional zone distribution of nature reserve should be further optimized and adjusted. We suggested that other hotspots should become part of the core area, including the Longwangtang area of Puli River, Xiaoyakou, Dengjiawan, Dongziyan, Longwangtang, Jiuwuju, Huatouju, Xinpuzi and Longjia yard of Baijiaxi Stream. The cold spots should be removed from the core area, to improve the function zoning of nature reserve. Our results could provide quantitative basic references for the boundary optimization and control zoning of nature reserve, and the reasonable promotion of the adjustment of "three zones to two zones", and could have guiding significance for improving effectiveness of species conservation and formulating scientific protection strategies.

DNA Metabarcoding of Deep-Sea Sediment Communities Using COI: Community Assessment, Spatio-Temporal Patterns and Comparison with 18S rDNA

Among the complex ecosystems and habitats that form the deep sea, submarine canyons and open slope systems are regarded as potential hotspots of biodiversity. We assessed the spatial and temporal patterns of biodiversity in sediment communities of a NW Mediterranean Canyon and its adjacent open slope (Blanes Canyon) with DNA metabarcoding. We sampled three layers of sediment and four different depths (900–1750 m) at two seasons, and used a fragment of the mitochondrial gene cytochrome c oxidase subunit I (COI) as a metabarcoding marker. The final dataset contained a total of 15,318 molecular operational taxonomic units (MOTUs). Metazoa, Stramenopiles and Archaeplastida were the dominant taxa and, within metazoans, Arthropoda, Nematoda and Cnidaria were the most diverse. There was a trend towards decreasing MOTU richness and diversity in the first few cm (1 to 5) of the sediment, with only 26.3% of the MOTUs shared across sediment layers. Our results show the presence of heterogeneous communities in the studied area, which was significantly different between zones, depths and seasons. We compared our results with the ones presented in a previous study, obtained using the v7 region of the 18S rRNA gene in the same samples. There were remarkable differences in the total number of MOTUs and in the most diverse taxa. COI recovered a higher number of MOTUs, but more remained unassigned taxonomically. However, the broad spatio-temporal patterns elucidated from both datasets coincided, with both markers retrieving the same ecological information. Our results showed that COI can be used to accurately characterize the studied communities and constitute a high-resolution method to detect ecological shifts. We also highlight that COI reference databases for deep-sea organisms have important gaps, and their completeness is essential in order to successfully apply metabarcoding techniques.

Species richness, range size, and wing development in South American melanopline grasshoppers (Orthoptera, Acrididae)

1. Wing development can influence biogeographic patterns, and much debate has been focused on the ecological conditions that favour secondary wing reductions in insects. Although grasshoppers are mostly flight‐capable, brachypterism appears to be common in many species and has been typically associated with limited dispersal abilities.2. This study presents the first comprehensive analysis of biodiversity patterns in South American melanopline grassshoppers. Two different macroecological methodologies were applied: a range–diversity plots approach and generalised lineal models (GLMs). The study simultaneously considered three features (species richness, range size, and wing development) and four potentially explanatory hypotheses that can influence geographic biodiversity patterns: energy, environmental heterogeneity, seasonality, and habitat suitability hypotheses.3. These analyses of dispersal abilities and distributional data indicate a clear and consistent association between wing development and biogeographical patterns in South American melanopline grasshoppers. Brachyptery was related to small distribution sizes, whereas the opposite was true for macroptery. Melanopline species richness is best explained by all the environmental hypotheses considered in the analysis (energy, environmental heterogeneity, seasonality, and habitat suitability hypotheses), whereas geographic range size is explained by the environmental heterogeneity and seasonality hypotheses.4. Models indicate a stronger association with range size than with species richness, and it is therefore considered that range size is a key feature to elucidate the spatial patterns of biodiversity. Despite the relevance of species richness and range sizes as descriptors of macroecological and biodiversity patterns, these features are seldom investigated simultaneously.

Hotspots of biotic compositional change in lakes along vast latitudinal transects in northern Canada.

Ecotones mark zones of rapid change in ecological structure at various spatial scales. They are believed to be particularly susceptible to shifts caused by environmental transformation, making them key regions for studying the effects of global change. Here, we explored the variation in assemblage structure of aquatic primary producer and consumer communities across latitudinal transects in northeastern North America (Québec-Labrador) to identify spatial patterns in biodiversity that indicated the location of transition zones across the landscape. We analyzed species richness and the cumulative rate of compositional change (expressed as beta-diversity) of diatoms and chironomids to detect any abrupt shifts in the rate of spatial taxonomic turnover. We used principal coordinates analysis to estimate community turnover with latitude, then applied piecewise linear regression to assess the position of ecotones. Statistically significant changes in assemblage composition occurred at 52 and 55°N, corresponding to the transition between closed- and open-crown forest, and to the southern onset of the forest tundra (i.e., the forest limit), respectively. The spatial distribution of ecotones was most strongly related to air temperature for chironomids and to vegetation- and soil-related chemical attributes of lake water for diatoms, including dissolved organic carbon content and water color. Lakes at mid- to high-latitudes currently face pressures from rapidly rising temperatures, accompanied by large increases in organic carbon inputs from their catchments, often leading to browning and its associated effects. The biota at the base of food webs in lakes located in transition zones are disproportionately affected by the cascading effects of these multi-factorial changes, concurrent with pronounced terrestrial greening observed in these regions. Similar patterns of biotic shifts have been observed along alpine aquatic transects, indicating the potential for widespread restructuring of cold, high-altitude and high-latitude freshwater communities due to global change.

Urbanization and Human Population Favor Species Richness of Alien Birds

Human activities like urbanization and agriculture affect spatial biodiversity patterns. The presence and activities of humans richly benefit alien species, but native species usually decline in human-impacted areas. Considering that the richness of alien and native species are inter-related, we explored the effect of human population density, human-related land uses (agricultural and urban), and natural land area on avian (alien and native) species richness of Massachusetts for two time periods using Generalized Additive Models. Avian alien species richness increased with native species richness in both time periods. Despite the predominant role of native species richness as a major driver of alien species richness, human activities play an important additional role in shaping species richness patterns of established aliens. Human-related land uses (urban and agricultural) and human population favored alien species richness in both time periods. Counter to expectations, human activities were also positively associated to native avian species richness. Possible explanations of these patterns may include habitat heterogeneity, increased availability of resources, and reduced predation risk.

Identifying conservation priorities in a defaunated tropical biodiversity hotspot

AbstractAimUnsustainable hunting is leading to widespread defaunation across the tropics. To mitigate against this threat with limited conservation resources, stakeholders must make decisions on where to focus anti‐poaching activities. Identifying priority areas in a robust way allows decision‐makers to target areas of conservation importance, therefore maximizing the impact of conservation interventions.LocationAnnamite mountains, Vietnam and Laos.MethodsWe conducted systematic landscape‐scale surveys across five study sites (four protected areas, one unprotected area) using camera‐trapping and leech‐derived environmental DNA. We analysed detections within a Bayesian multispecies occupancy framework to evaluate species responses to environmental and anthropogenic influences. Species responses were then used to predict occurrence to unsampled regions. We used predicted species richness maps and occurrence of endemic species to identify areas of conservation importance for targeted conservation interventions.ResultsAnalyses showed that habitat‐based covariates were uninformative. Our final model therefore incorporated three anthropogenic covariates as well as elevation, which reflects both ecological and anthropogenic factors. Conservation‐priority species tended to found in areas that are more remote now or have been less accessible in the past, and at higher elevations. Predicted species richness was low and broadly similar across the sites, but slightly higher in the more remote site. Occupancy of the three endemic species showed a similar trend.Main conclusionIdentifying spatial patterns of biodiversity in heavily defaunated landscapes may require novel methodological and analytical approaches. Our results indicate that to build robust prediction maps it is beneficial to sample over large spatial scales, use multiple detection methods to increase detections for rare species, include anthropogenic covariates that capture different aspects of hunting pressure and analyse data within a Bayesian multispecies framework. Our models further suggest that more remote areas should be prioritized for anti‐poaching efforts to prevent the loss of rare and endemic species.

Multitrophic biodiversity patterns and environmental descriptors of sub‐Arctic lakes in northern Europe

Abstract Arctic and sub‐Arctic lakes in northern Europe are increasingly threatened by climate change, which can affect their biodiversity directly by shifting thermal and hydrological regimes, and indirectly by altering landscape processes and catchment vegetation. Most previous studies of northern lake biodiversity responses to environmental changes have focused on only a single organismal group. Investigations at whole‐lake scales that integrate different habitats and trophic levels are currently rare, but highly necessary for future lake monitoring and management. We analysed spatial biodiversity patterns of 74 sub‐Arctic lakes in Norway, Sweden, Finland, and the Faroe Islands with monitoring data for at least three biological focal ecosystem components (FECs)—benthic diatoms, macrophytes, phytoplankton, littoral benthic macroinvertebrates, zooplankton, and fish—that covered both pelagic and benthic habitats and multiple trophic levels. We calculated the richnessrelative (i.e. taxon richness of a FEC in the lake divided by the total richness of that FEC in all 74 lakes) and the biodiversity metrics (i.e. taxon richness, inverse Simpson index (diversity), and taxon evenness) of individual FECs using presence–absence and abundance data, respectively. We then investigated whether the FEC richnessrelative and biodiversity metrics were correlated with lake abiotic and geospatial variables. We hypothesised that (1) individual FECs would be more diverse in a warmer and wetter climate (e.g. at lower latitudes and/or elevations), and in hydrobasins with greater forest cover that could enhance the supply of terrestrial organic matter and nutrients that stimulated lake productivity; and (2) patterns in FEC responses would be coupled among trophic levels. Results from redundancy analyses showed that the richnessrelative of phytoplankton, macrophytes, and fish decreased, but those of the intermediate trophic levels (i.e. macroinvertebrates and zooplankton) increased with decreasing latitude and/or elevation. Fish richnessrelative and diversity increased with increasing temporal variation in climate (temperature and/or precipitation), ambient nutrient concentrations (e.g. total nitrogen) in lakes, and woody vegetation (e.g. taiga forest) cover in hydrobasins, whereas taxon richness of macroinvertebrates and zooplankton decreased with increasing temporal variation in climate. The similar patterns detected for richnessrelative of fish, macrophytes, and phytoplankton could be caused by similar responses to the environmental descriptors, and/or the beneficial effects of macrophytes as habitat structure. By creating habitat, macrophytes may increase fish diversity and production, which in turn may promote higher densities and probably more diverse assemblages of phytoplankton through trophic cascades. Lakes with greater fish richnessrelative tended to have greater average richnessrelative among FECs, suggesting that fish are a potential indicator for overall lake biodiversity. Overall, the biodiversity patterns observed along the environmental gradients were trophic‐level specific, indicating that an integrated food‐web perspective may lead to a more holistic understanding of ecosystem biodiversity in future monitoring and management of high‐latitude lakes. In future, monitoring should also focus on collecting more abundance data for fish and lower trophic levels in both benthic and pelagic habitats. This may require more concentrated sampling effort on fewer lakes at smaller spatial scales, while continuing to sample lakes distributed along environmental gradients.

Use of openly available occurrence data to generate biodiversity maps within the South African EEZ

Biodiversity maps are an important component of ecosystem-based management and conservation. In the past, biodiversity maps were largely generated using patchy occurrence data from a range of data sources. Currently, substantial species occurrence data are readily available for large parts of the world and are accessible programmatically. Considering both the observed and expected changes in species distributions, and hence biodiversity, in response to present and future climate change, it is important to utilise readily available species occurrence databases to generate temporal and spatial biodiversity maps. In this study biodiversity maps were generated for three generic functional groups within the exclusive economic zone of South Africa: zooplankton, fishes and benthos. This was achieved by stacking individual species-distribution maps. Freely available occurrence data from the Ocean Biogeographic Information System (OBIS) were accessed for this purpose. Ensemble species-distribution modelling, employing five widely used statistical methods, was used to generate species-distribution maps for each functional group. The resulting spatial patterns of biodiversity for the three functional groups were largely in agreement with known patterns. The results of this study highlight the value of open-source occurrence and environmental data to generate biodiversity maps that can potentially be used in future spatial prioritisation or planning for management of marine areas and in environmental-change studies.

Seasonality of spatial patterns of abundance, biomass, and biodiversity in a demersal community of the NW Mediterranean Sea

Abstract Information on the spatial patterns and habitat preferences of marine species is key to understand the functioning of marine ecosystem and to manage and protect marine resources efficiently. However, the study of spatial patterns of marine ecosystems is challenging because they are dynamic environments that can vary seasonally. We modelled the spatial patterns of abundance, biomass, and biodiversity in a demersal community of the northwestern Mediterranean Sea by season using hierarchical Bayesian spatial models and environmental, physical, and anthropogenic factors. Overall, our findings revealed the importance of seasonality in the spatial patterns of the demersal community, which were mainly driven by sea surface temperature. Results also underlined important patterns of movements of demersal organisms: fishes, cephalopods, and crustaceans showed high densities in the area surrounding the Ebro Delta River in winter mainly driven by species-specific behaviour. Our results are relevant to inform future management measures in the study area, such as seasonal fishing restrictions, or to adapt local marine protected areas to seasonal processes. This study provides evidence of the need to expand current monitoring schemes to capture the seasonality of marine demersal communities for a more comprehensive marine spatial planning framework.

Patterns of fish community composition and biodiversity in riverine fish sanctuaries in Bangladesh: Implications for hilsa shad conservation

AbstractUnderstanding biodiversity and community composition is a prerequisite to sustainable exploitation and conservation of fisheries. We assessed the spatial and seasonal patterns of fish community composition and biodiversity in seasonal no‐take riverine sanctuaries in Bangladesh, which aim to conserve the anadromous hilsa shad (Tenualosa spp. and Hilsa keele). Fish samples were collected during monsoon, as well as pre‐ and postmonsoon, from five sites within two sanctuaries and one site in an open fishing area. Although total abundance was similar along the rivers, species richness was significantly higher at the open fishing site due to its connectivity to nearby habitats. The diversity apparently decreased in a downstream direction. Fish communities at two upstream sites were separated from other sites in multivariate space largely due to higher abundance of hilsa at downstream sites and presence of floodplain‐oriented species at the two upstream sites. Short body length and high trophic level at all sites indicated that fish communities were overexploited. Our results also indicated that riverine hilsa sanctuaries in Bangladesh are rich in fish species diversity and support several threatened species designated by the International Union for Conservation of Nature (IUCN). Our study also suggested that since hilsa abundance shapes community patterns, it can therefore impact riverine ecosystem functioning in the sanctuary areas. The findings of this study can serve as an important baseline for future biodiversity assessment, conservation and impact assessment of conservation in rivers, and therefore help to establish multispecies ecosystem‐based management of riverine fisheries around the world.

Role of benthic habitat structure and riverine connectivity in controlling the spatial distribution and ecology of estuarine fish

Estuaries are among the most productive ecosystems per unit area, but this productivity is unevenly distributed across a complex mosaic of habitats. Identifying the qualities of different habitats that influence the composition and productivity of biotic communities is fundamental to understanding the dynamics of these ecosystems. We combined field surveys, hydrological modelling and stable isotope analysis to understand the roles of habitat, hydrological connectivity, salinity and temperature in determining assemblage composition, species abundance and trophic ecology of an estuarine fish community. Hydrodynamics, vegetation matrices of macroalgae and seagrass and the presence of epiphytes on vegetation explained spatial patterns in taxonomic biodiversity, multivariate assemblage structure and the occurrence of juvenile black bream Acanthopagrus butcheri, a species that possesses ecological traits common tomany demersal estuarine fish species. Juvenile bream abundance was related to vegetation composition (particularly epiphyte presence), supporting the hypothesis that juvenile habitats that provided resources or conditions that ex - tended beyond just structure conferredmore ecological advantages. This was further evidenced by stable isotope-based estimates of basal resource contributions of epiphytes. Our findings suggest that hydrodynamic connectivity with riverine water masses acts as a coarse determinant for estuarine fish communities at large spatial scales. At smaller scales, habitat-level associations influence local abundances and the identity and importance of specific trophic resources. Coupling hydro - dynamic modellingwith natural biomarkers provides a powerful approach for assessing the spatial context of habitat use that can help resource managers prioritize monitoring and habitat preservation efforts for coastal fish communities in a changing global environment.

Inventory incompleteness and collecting priority on the plant diversity in tropical East Africa

Inventory incompleteness has seriously affected the accuracy of the spatial distribution pattern of biodiversity, but the causes of incompleteness and the priority investigation with quantitative methods have received far less attention. In this study, we constructed a plant database of tropical East Africa, evaluated and explained the inventory incompleteness, and identified the priority collecting area. The results showed that the spatial distribution pattern of collection density and species richness is very uneven in tropical East Africa, with 16 % of regions having zero-collection, and more than half of the regions having inventory incompleteness. Species collection and completeness are mainly affected by species richness and road density, followed by national boundaries and insecurity in some areas. We quantitatively selected priority investigation areas in tropical East Africa to supplement biodiversity data in the area. We recommend prioritizing collections especially around western Kenya, southern Tanzania, and around the border of Tanzania and Kenya. Future work should focus on improving the digitization of specimens and the strengthening of cooperation among countries, for these are the best ways to raise awareness of the biodiversity patterns in tropical East Africa.

Spatial and temporal homogenisation of freshwater macrofaunal communities in ditches

Abstract There is a widespread concern that we are witnessing an ongoing homogenisation of ecological communities. However, in contrast to human impacts on spatial patterns in biodiversity, human impacts on the temporal aspects of β‐diversity have received little attention. Moreover, the interplay between spatial and temporal β‐diversity is poorly understood. To address this knowledge gap, we assessed dissimilarity within freshwater macrofaunal communities of drainage ditches to determine spatiotemporal β‐diversity as well as homogenisation in relation to different types of land use. We considered four distinct changes in community composition: spatial turnover, temporal turnover, spatial variation over time, and temporal variation in space, as well as the combined effects of space and time on β‐diversity. As a metric of dissimilarity, we calculated the taxonomic Hellinger distance between samples from different locations and time points and correlated these with distance in space and in time, as well as with three spatial variables, including land‐use type, and two temporal variables. We studied the effect of interactions between spatial and temporal variables on dissimilarity by applying a permutational analysis of variance. Our results illustrate the importance of changes in community composition in time with respect to temporal turnover, spatial variation over time, and temporal variation in space. While we did not find spatial turnover in community composition, both month and year had a considerable effect. Within a year, β‐diversity decreased over the months, yet these assembly patterns differed between years. This suggests major effects of seasonal and year‐to‐year dynamics on β‐diversity. Land use was also observed to be a main driver: ditches in nature conservation areas had higher β‐diversity and temporal heterogeneity was lowest in ditches adjacent to the most intensive agricultural land‐use category, indicating that agricultural practices can homogenise biodiversity in both space and time. By analysing the spatial and temporal β‐diversity patterns in freshwater macrofaunal communities in concert, we have shown that β‐diversity is a sensitive and highly informative metric of both spatial and temporal changes in community composition.

Do hotspots fall within protected areas? A Geographic Approach to Planning analysis of regional freshwater biodiversity

Abstract Identification of biodiversity hot spots is necessary for developing conservation strategies. The south‐eastern U.S.A. harbours high aquatic biodiversity; however, this diversity is threatened as a result of anthropogenic activities. We report patterns of fish and mussel biodiversity, locate hotspots of diversity and endemism, and identify gaps in protection of these hotspots. Maxent was used to generate species distribution models for native fish and mussel species in river basins throughout east Texas. Stacked species distribution models were used to assess spatial patterns of biodiversity and examine the concordance between fish and mussel hotspots. A Geographic Approach to Planning analysis was used to identify areas of high conservation concern. Predicted geographical variation in species richness of mussels corresponds to patterns shown in fish; however, there was discordance among endemicity hotspots between the two taxa. Because overall endemicity was low in both groups, species richness is likely to be the more informative measure of biodiversity at these regional scales. While hotspots represent a small percentage of the study area, almost all richness and endemicity hotspots (>95%) in east Texas occur outside of protected areas. The results of this study suggest that protected areas designated based on terrestrial habitat may fail to protect aquatic biodiversity. Studies such as this provide a baseline for development of conservation and management strategies for protection of regional freshwater biodiversity, while also suggesting that designating conservation lands should include consideration of both terrestrial and aquatic biodiversity.

How to predict biodiversity in space? An evaluation of modelling approaches in marine ecosystems

AbstractAimBiodiversity prediction becomes increasingly important in the face of global diversity loss, whereas substantial challenges still exist in both conceptual and technical aspects. There exist many predictive models, and an integrative evaluation can help understand their performance in handling the multifacets of biodiversity. This study aims to evaluate the performance of these modelling approaches to predict both α‐ and β‐diversity in diverse ecological contexts.LocationNorth Yellow Sea, China.MethodsThe biodiversity models follow three strategies, “assemble first, predict later”, “predict first, assemble later” and “assemble and predict together”. Hill diversity profile, Fisher's log‐series parameter and the distance decay of similarity are used to measure α‐ and β‐diversity. The evaluation study is conducted based on seasonal bottom trawl surveys from October 2016 to August 2017 in North Yellow Sea, China, allocated to coastal and offshore areas. We evaluate the predictive power of the models using cross‐validation.ResultsFollowing the “assemble first, predict later” approach, macroecological model (MEM) provided the most accurate prediction overall, whereas stacked species distribution model (SSDM) and joint species distribution model (JSDM), following the second and third modelling approaches, tended to overestimate α‐diversity and underestimate β‐diversity. The performances of SSDM and JSDM could be improved by moderately down‐weighting rare species. The relative performances of the three modelling approaches were consistent among seasons and spatial regions.Main conclusionsThe superior performances of MEM in a range of temporal and spatial contexts favour the “assemble first, predict later” approach and imply a tight community assembly in the studied area. The overall predictive powers of varying models suggest that the spatial pattern of marine biodiversity could be fairly well predicted with commonly accessible hydrologic data in a mesoscales. The approach of multi‐model evaluations is applicable to a variety of ecosystems for biodiversity prediction.

Patterns in fish biodiversity associated with temperate reefs on the southeastern US continental shelf

Temperate reef fishes provide many benefits to humans including food, sport, and ecotourism, yet remain severely understudied compared to coral reef fishes in tropical environments. We used 3 years of underwater video data (n = 4130 samples) from hardbottom reefs along the continental shelf of the southeastern US Atlantic coast (i.e., North Carolina to Florida; ~ 100,000 km2) to quantify the spatial and temporal patterns of temperate reef fish biodiversity in the region. Overall, 210 taxa were identified on video from 53 families, 138 of which could be identified to the species level. Species with the highest percent occurrence were gray triggerfish (Balistes capriscus; observed on 45.6% of all videos), tomtate (Haemulon aurolineatum; 42.7%), and red porgy (Pagrus pagrus; 39.4%), and 23 species were observed on more than 10% of videos. Latitudinal variability swamped temporal changes (2015–2017) for most taxa. After accounting for the influence of water clarity and current direction on video detectability, generalized additive models suggested that species and family richness were highest at sites characterized by moderate depths, a high proportion of hardbottom, high substrate relief, and warm water. Our results can be used to predict areas of highest reef fish biodiversity at large (regional) and small (microhabitat) scales to improve marine protected area design, delineate essential fish habitats, and parameterize ecosystem models.

Biogeography of soil bacterial populations in the Jutulsessen and Ahlmannryggen of Western Dronning Maud Land, Antarctica

Soils of continental Antarctic nunataks represent unusual ecosystems with concomitant unique bacterial community profiles which have not been assessed for the vast majority of Antarctic nunataks. This study focussed on the previously uncharacterised inland nunataks of the Jutulsessen and Ahlmannryggen ranges in Dronning Maud Land. As with many oligotrophic soils in Antarctica, bacteria from the phyla Acidobacteria, Actinobacteria and Proteobacteria were prevalent. High relative abundances of Bacteroidetes and Chloroflexi were also observed in these soils. Potential phototrophic capabilities of these bacterial populations were indicated by the presence of genes involved in the Calvin–Benson reductive pentose phosphate cycle as well as that of aerobic phototrophic bacteriochlorophyll. Clear spatial patterns of bacterial biodiversity between nunataks in this study were observed, particularly between the Jutulsessen and Ahlmannryggen nunataks which are geographically separated by the Jutulstraumen glacier. Not unexpectedly, the bacterial community profiles found in these nunataks were distinct from those found in alternate biogeographic regions (e.g. Dry Valleys, Peninsula and Larsemann Hills). Despite belonging to the same bioregion (i.e. Dronning Maud Land), however, the clear differentiation of bacterial communities between the Jutulsessen/Ahlmannryggen and that of Sor Rondane suggests that, based on bacterial phylogeography, the Dronning Maud Land bioregion can be divided into sub-bioregions.

Spatial analysis of biodiversity soil macrofauna in Populus deltoides plantation of northern forests of Iran

Information about the spatial patterns of soil biodiversity and understanding the effects of biodiversity on ecosystem processes are limited. This study was conducted to determine whether biodiversity of soil macrofauna features demonstrate spatial patterns in the Populus deltoides plantation in north of Iran. 150 soil samples were taken using a grid sample of 40 × 40 m. Soil macrofaunawere sampled by digging and hand sorting two 50 × 50 cm areas into a depth of 20 cm in each treatment.Abundance (the number of macrofauna) diversity (Shannon-Weiner index), richness (Menhinick index) and evenness (Smith–Wilson index) were calculated using geostatistics (variogram) in order to describe and quantify the spatial continuity. Some soil chemical and physical properties were determined. The variograms of variable revealed the presence of spatial autocorrelation. The range of influence was 710.9 m for abundance, 650.3 m for diversity, 720.90 m for richness and 410.9 m for evenness. The kriging maps indicated that the soil macrofauna have spatial variability. Moreover, the spatial pattern of macrofauna biomass is similar to the pattern of clay and pH of soil.

Modelling the spatial pattern of biodiversity utilizing the high-resolution tree cover data at large scale: Case study in Yunnan province, Southwest China

Explicit biodiversity level at large spatial scale is often indicated by species richness. The spatial variability of species richness has been postulated to be related with influencing factors such as climate, habitat and human activities using many geostastical methods. Understanding the relationship between species richness and its influencing factors is of critical importance for its conservation. As tree cover data with high resolution can reflect the terrestrial habitat with environment, its efficiency for modelling spatial pattern of biodiversity was investigated in this study. The spatial distribution of tree cover and its influencing factors in Yunnan province, and the relationship between tree cover and species richness of mammals and birds were analyzed by linear regression method and Geographically Weighted Regression (GWR) model. The results showed that tree cover in this study region exhibited a substantially spatial heterogeneity, which was affected by human activities, topography and climate. Linear regression analysis showed that tree cover was significantly correlated with the species richness of mammals and birds. The explanatory power (local R2) of GWR model between tree cover and species richness of mammals and birds showed great spatial variability. The predicted spatial distribution of species richness of mammals and birds was consistent with the actual observed values. Our study revealed that the GWR model provides local details of spatial variation in species richness of mammals and birds. These results will be helpful to understand the impact of tree cover on variation of species richness of mammals and birds under global change and will be of theoretical significance for better conservation and management of biodiversity.

Effects of publication bias on conservation planning.

Conservation planners need reliable information on spatial patterns of biodiversity. However, existing data sets are skewed because some ecosystems, taxa, and locations are underrepresented. We determined how many articles have been published in recent decades on the biodiversity of different countries and their constituent provinces. We searched the Web of Science catalogues Science Citation Index (SCI) and Social Science Citation Index (SSCI) for biodiversity-related articles published from 1993 to 2016 that included country and province names. We combined data on research publication frequency with other provincial-scale factors hypothesized to affect the likelihood of research activity (i.e., economic development, human presence, infrastructure, and remoteness). Areas that appeared understudied relative to the biodiversity expected based on site climate likely have been inaccessible to researchers for reasons, notably armed conflict. Geographic publication bias is of most concern in the most remote areas of sub-Saharan Africa and South America. Our provincial-scale model may help compensate for publication biases in conservation planning by revealing the spatial extent of research needs and the low cost of redoing this analysis annually.