Species Composition Patterns Research Articles

Patterns in diversity and species composition in soft-sediment tidepool fishes across topographical types: Implications for conservation with spatial nuances

Fish communities inhabiting soft-sediment areas are representative conservation targets for coastal habitats, but how the ecological function of soft-sediment tidepools drives diversity is still unknown. To tackle this issue, the ecological functions of soft-sediment tidepools for fishes according to topographic types (open and closed habitats) on Okinawa-jima Island, located in subtropical Japan, were examined in diversity, species composition, and lifestyle (resident and transient species). Landward tidepools serve as permanent habitat for specialists, whereas seaward tidepools are more important for transient species as temporal habitats, which shaped the inverse trend in α- and β-diversity between topographic types, depending on the habitat heterogeneity and the biological characteristics of resident and transient species. We propose a strategy for the conservation and management of topographically distinct intertidal habitats, basically as a single set, while also considering the ecological functions with spatial nuances at smaller scales within coastal landscapes.

Resident Birds Show Different Patterns in Species Composition and Functional Diversity in Differently Managed Coffee Plantations in the Western Ghats, India

Understanding the patterns and drivers of bird species composition and diversity outside Protected Area networks is essential to develop landscape-level conservation strategies. The Western Ghats' coffee plantations of India form an important agro-ecosystem and help maintain a significant portion of regional avian diversity. However, knowledge of the composition and functional diversity of birds in differently managed coffee plantation is lacking from the Western Ghats. In this study, we compared the composition and functional diversity of resident birds between shade and open coffees plantations. We counted 3,846 birds of 87 species, and found species richness to be higher in shade (78 species) than in open coffee plantations (55 species). Interestingly, 32 species were unique to shade and nine were unique to open coffee plantations, with 46 species found in both types of plantation. Overall species composition and functional diversity were different in differently managed plantations. Species richness and abundance (birds/point/visit) were higher in shade coffee, reflecting the availability of multiple strata and habitat heterogeneity. Results revealed that different farm management practices can affect functional bird richness and its abundance in coffee plantations. Therefore, retaining shade-trees of native varieties in coffee plantations is important for supporting high functional diversity, richness, and abundance of birds in the coffee plantation of the Western Ghats.

Different heights of resprouting by trees: Response to small-scale environmental restrictions in a non-fire-prone Caatinga tropical dry forest

Resprouting is an ecological strategy widely adopted by trees in response to different restrictive factors, in which the stems can be emitted at different heights of the tree. Although the patterns of resprouting height are already known in response to some restrictive factors (such as fire), their occurrence is not well elucidated in non-fire prone dry environments where continuous resource restriction may stimulate resprouting. Here, we assessed the general ecological dominance of resprouting trees in the community and the ecological dominance of trees resprouting at different heights in response to environmental restrictions in a tropical dry forest (TDF). We used multi-stemmed trees as a proxy for resprouting in response to the local restrictive factors. Our hypotheses were: i) resprouting trees have greater ecological dominance (more trees and stems and higher biomass) in more restrictive plots; ii) the ecological dominance of lower-height resprouting trees is greater in more restrictive plots, while the dominance of upper-height resprouting trees is greater in less restrictive plots. For this, we used a dataset of 27 TDF plots where we measured and identified the trees that met the inclusion criterion (3 cm of diameter at breast height) and collected soil samples to gather data on environmental restriction. Multi-stemmed trees were classified according to the height of additional-stem emission (below-ground, ground-level, and above-ground), considering the bottom-most stem originating from the main stem. We then evaluated whether the ecological dominance of resprouting trees and trees with different resprouting heights varied significantly in response to environmental restrictiveness, and patterns of species composition in the height categories. We found a greater dominance of resprouting trees in more restrictive environments, with lower-height resprouting trees dominating the most restrictive plots (two hypotheses confirmed). This finding may be associated with physiological mechanisms of drought response because resprouting height is directly associated with the level of damage inflicted on the internal structure of trees. We also found that the species varied in their ability for stem emission at different heights, whereby the most plastic species were more dominant compared to those with just one height of emission. This finding indicates that different restrictive factors can produce similar resprouting expressions, reinforcing the need to advance the knowledge on the importance of resprouting in TDF.

Distinguishing Original and Non-Original Stands at the Zhanjiang Mangrove National Nature Reserve (P.R. China): Remote Sensing and GIS for Conservation and Ecological Research

The present research developed a novel methodological framework to differentiate natural mangrove stands (i.e., original), from stands which were planted and stands naturally established after interaction between planted and non-planted stands (e.g., through pollination, i.e., non-original). Ground-truth and remote sensing data were collected for Zhanjiang Mangrove National Nature Reserve (ZMNNR) in P.R. China. First, satellite images of Corona (1967) and GeoEye-1 (2009) were overlaid to identify original (1967) and non-original (2009) mangrove stands. Second, in both stands a total of 75 in situ plots (25 m2) were measured for ground-truthing of tree structural parameters including height, density, basal area and Complexity Index (CI). From temporal satellite data, we identify 236.12 ha of original mangrove and 567.88 ha of non-original mangrove in the reserve. Averaged measurements of the original mangrove stands, i.e., stem density (1164 nos. 0.1 ha−1), basal area (90.3 m2 0.1 ha−1) and CI (100.59), indicated that they were in a state of maturity and less disturbed compared to the non-original mangroves (density, 1241 nos. 0.1 ha−1; basal area, 4.92 m2 0.1 ha−1 and CI, 55.65). The Kruskal–Wallis test showed significant differentiation between the original and non-original mangrove tree structural parameters: Kandelia obovata’s density, X2 = 34.78, d.f. = 1, p = 0.001; basal area, X2 = 108.15, d.f. = 1, p = 0.001; Rizhopora stylosa’s density, X2 = 64.03, d.f. = 1, p = 0.001; basal area, X2 = 117.96, d.f. = 1, p = 0.001. The latter is also evident from the clustering plots generated from the Principal Component Analysis (PCA). Vegetation dynamics at the ZMNNR also enabled us to compare the species composition and distribution patterns with other Indo-West Pacific regions. Overall, the present study not only highlights the advantage of >50 years old satellite data but also provide a benchmark for future ecological research, conservation and management of the ZMNNR.

Species composition and distribution patterns of the Mangrove forests of the Western Niger Delta, Nigeria

ABSTRACT This study examined species composition and occurrence pattern among mangroves across the Western Niger Delta. Vegetation measurements were carried out in one hundred quadrats of 20m by 20m. Rhizophora spp was dominant in Burutu, Opuama, Kurutie, Control (Importance Value Index =300, 177.28, 237.65, 300). A.germinans was dominant in Agge (IVI =183.03). Adult Rhizophora spp were dispersed in Agge, Burutu, Control (Morisita Index =0.25, 1.02, 0.025). Adult A. germinans were dispersed in Kurutie, Opuama, Agge (MI =0.07, 0.08, 0.26). Rhizophora spp juveniles were clustered in Agge, Burutu, Opuama, Kurutie, Control (MI =1.17, 1.86, 1.47, 1.9, 1.14). A. germinans juveniles were dispersed in Kurutie, Agge (MI =0.06, 0.69). Restoration and conservation programs should be established.

Spatial patterns and key drivers of zooplankton in the north central Indian Ocean

ABSTRACT Zooplankton is a vital component in the pelagic marine ecosystems, linking lower to higher trophic levels. A survey was conducted with R/V Dr. Fridtjof Nansen in Sri Lankan waters in summer 2018 to explore zooplankton dynamics in relation to abiotic and biotic variables. A distinct pattern in physical and biological properties characterized Sri Lankan waters into two ecosystems: (1) low production, high temperature, and low salinity in the east, and (2) high production, low temperature, and high salinity in the west. The highest mean abundance (1931 ind. m−3) and biomass (1.79 g dry wt. m−2) of zooplankton were significantly associated with cooler, high saline, and more productive waters in the North West and South West. In general, zooplankton were significantly more abundant in the west (1841 ind. m−3) than the east (707 ind. m−3). The most abundant copepod families were Paracalanidae (20.4%) and Tachidiidae (10.2%). The copepod Paracalanus parvus was the most dominant species. Our study reveals that temperature is a key driver explaining 67% of the variance in zooplankton biomass in this region. This study provides novel baseline results on spatial patterns of zooplankton abundance, biomass, and species composition from an understudied region of the north central Indian Ocean.

The different facets of native bird diversity (taxonomic, functional and phylogenetic) as predictors of alien birds increasing richness and expanding range in Great Britain

Native-alien species relationship is one of the potential mechanisms to explain alien species' success. Most approaches have so far focused on species richness, but species-centric approaches alone are of limited explanatory ability. We utilized the breeding bird atlases of Great Britain at three time points, to examine the temporal patterns of alien bird species assemblages' richness and composition and analyze the spatio-temporal relationship between them and native species functional and phylogenetic diversity. Alien birds were successful in increasing their average local richness and range from the 1970s to the 2010s, without high values of the replacement component of β-diversity in most assemblages and with increasing richness in the majority of atlas cells. Communities with higher native diversity were positively associated with higher alien species richness and overall, our results showed that native biodiversity metrics can act as reliable predictors of alien species richness patterns. Native phylogenetic diversity emerged as an important predictor of alien species richness, whereas functional diversity was not as successful. Phylogenetic diversity may have captured native species' functional differences more effectively and/or the added layer of phylogenetic information increased phylogenetic diversity's ability to predict alien species richness patterns and may be indicative of evolutionary processes reflecting the mechanisms shaping native-alien species' relationship. If we were to predict where these alien birds may spread within the next 20 years, our results point to phylogenetically rich communities. This is likely a reflection of habitat heterogeneity and/or resource availability in these communities. In any case, a multifaceted approach is preferable, as different measures highlight different mechanisms driving communities' invasibility.

Patterns of phytoplankton community structure and diversity in aquaculture ponds, Henan, China

In aquaculture, phytoplankton contribute to primary productivity, helping maintain fishery harvests and water stabilization. To better understand the drivers controlling phytoplankton communities, sampling was conducted during two seasons in 185 aquaculture ponds that cultured five species of aquatic animals (channel catfish, common carp, grass carp, crayfish and largemouth bass). Principal coordinate analysis (PCoA), redundancy analysis (RDA), and generalized linear model (GLM) were applied to quantify the relative importance of multiple factors to phytoplankton species composition and diversity. The PCoA results demonstrated that in spring, phytoplankton species composition showed no distinct differences among the 5 cultivated-animal ponds. In summer, phytoplankton species composition had a distinct pattern, which was clustered into three distinct groups. The RDA results revealed that the variation in the phytoplankton composition was closely correlated with the water temperature, conductivity, dissolved organic carbon (DOC), alkalinity, and nitrate in spring. In summer, different variables, including cultivated animals, alkalinity, pH and dissolved oxygen (DO), were responsible for explaining species composition patterns. In spring, no significant difference in phytoplankton α-diversity was found among the 5 cultivated-animal ponds. In summer, significantly higher α-diversity was found in the channel catfish and crayfish ponds than in the other ponds. GLM analysis showed that phytoplankton density, cultivated animals, and conductivity can be used to explain phytoplankton diversity. Although no effect of cultivated animals was found during the early aquaculture stage, the results from the summer samples demonstrated that cultivated animals have an important influence on phytoplankton communities. Therefore, we suggest that in intensive fish-stocking ecosystems, top-down effect is an important strength on phytoplankton communities. In terms of preventing algal blooms, a low density of phytoplankton is important for maintaining high phytoplankton diversity and water stabilization in aquaculture. Our results can provide useful information for water management practices in aquaculture ponds.

Moth diversity, species composition, and distributional pattern in Aravalli Hill Range of Rajasthan, India.

Moths are phytophagous, cosmopolitan, agricultural pests, night pollinators, chiefly nocturnal and potential bio-indicators. The current study will be the first report on species diversity, species composition, abundance, and distributional pattern of moth fauna in Aravalli Hill Range Rajasthan. During the survey period of 2018–2019, 758 specimens of moths were collected pertaining to 34 species, 26 genera belonging to 05 families, and 13 subfamilies from three different sites of Aravalli Hill Range. Based on the number of genera, family Sphingidae was most dominant with 9 genera, and family Crambidae was least dominant with 2 genera. Based on the number of species, the family Sphingidae was the most dominant, representing 13 species, followed by Erebidae representing 11 species, Saturniidae and Noctuidae with 4 species each, the least dominant was Crambidae with 2 species. The diversity indices for moths have been calculated for the first time from the Aravalli Range of Rajasthan. Across the survey, Simpson’s Diversity Index (D′), Shannon Diversity Index (H′), Dominance & Evenness was calculated as 0.95, 3.3, 0.04, and 0.8, respectively, which reflects that moth fauna is diverse in the surveyed areas.

Patterns of Ant Diversity in the Natural Grasslands of Southern Brazil.

In the south of Brazil, grasslands are naturally widespread over two different biomes, the Pampa in the southernmost region and within the Atlantic Forest in the northern portions. The natural grasslands of the state of Paraná comprise a very particular physiognomy composed of two distinct formations: the Campos Gerais and the grasslands of the southwest. The first is located in the edge of the second plateau of Paraná state, comprising a great diversity of environments. The grasslands of the southwest are more homogeneous, with a continuous herbaceous stratum dominating the landscape. In this context, the aim of this study was to evaluate the patterns of species richness and composition of ants, an ecologically prominent group, along the natural grasslands of Paraná. We also intended to compare the faunal similarity between the two different grassland formations. For that, four different Conservation Unities were sampled along a latitudinal gradient. A remarkable total of 245 ant species was recorded, and the results indicate that species richness decreases as latitude increases along the grasslands of Paraná. There were clear differences in species composition between these two grasslands formations, given the significative number of endemic species in each of these two grassland formations. Ten species were recorded for the first time in the state of Paraná, of which three also for the first time in the Southern Region of Brazil. Overall, our study contributes to a better understanding about the diversity and composition of ant communities in subtropical grasslands.

Local environmental factors shape liana community structure along an elevation gradient in a tropical rainforest

ABSTRACT Knowledge of the drivers of liana community structure is fundamental to understand the processes driving community assembly. We investigated variation in liana community structure (diversity, composition, abundance, basal area, distribution) among different elevations, and assessed the environmental factors structuring composition and distribution. We randomly established thirty 20 × 20 m plots across three elevations (lower = 200 m a.s.l.; middle = 500 m a.s.l.; upper = 850 m a.s.l.) in the Mount Jerai Forest Reserve, Malaysia. We used Canonical Correspondence Analysis to assess the relationships between liana species distribution and composition, and environmental factors. Liana diversity differed significantly among elevations, being highest and lowest in the middle and upper elevations, respectively. Liana abundance and basal area were higher at lower elevations. Species abundance varied significantly across elevations. The environmental factors showed significant variation among the elevations. Liana species composition and distribution patterns were explained by elevation, soil moisture, Ca, P, pH and N. The different environmental factors affected species composition and distribution in different ways. These findings increase our understanding of the drivers of liana community structure and may be useful in liana management and conservation.

Seasonal Abundance of Culicoides at Yongsan US Army Garrison (USAG) and Camp Humphreys USAG, Republic of Korea, 2010-2013 and 2014-2017.

Biting midges (Culicoides: Ceratopogonidae) were collected using New Jersey light traps at Yongsan US Army Garrison (USAG;urban), Seoul Metropolitan city and Camp Humphreys USAG (rural), Pyeongtaek, Gyeonggi-do (province), Republic of Korea, from May-October 2010–2013 and 2015–2017, to determine species composition and seasonal distribution patterns in urban and rural habitats. A total of 9,958 female (53.85%) and 8,533 male (46.15%) Culicoides comprising 16 species were collected. Overall, the most commonly collected species was Culicoides arakawae (74.3%), followed by C. circumscriptus (16.2%), C. kibunensis (2.5%), C. nasuensis (2.2%), C. clavipalpis (1.4%), and C. pallidulus (1.3%), while the remaining 10 species accounted for <2.1% of all Culicoides spp. collected. The 2 predominant species collected were C. circumscriptus (47.4%) and C. arakawae (33.4%) at Yongsan, and C. arakawae (90.4%) and C. circumscriptus (3.9%) at Camp Humphreys. The seasonal abundance of these 2 species varied between years and between sites but on average peaked in August–September for C. arakawae and June–July for C. circumscriptus. Annual variations in abundance were observed for most species collected during this study. Unusually high proportions of male specimens were observed for most species at both sites which may be due to the use of the New Jersey trap.

Diversity and activity patterns of medium- and large-sized terrestrial mammals at the Los Tuxtlas Biosphere Reserve, México

Studies on diversity of animal communities allow determination of their species richness and composition. This information is particularly relevant to establish sound conservation programs in biosphere reserves, where human activities should be focused on the sustainable use of natural resources and ensure biodiversity protection. This study estimated the diversity and species richness and determined the species composition and activity patterns of medium- and large-sized terrestrial mammals in the Los Tuxtlas Biosphere Reserve (LTBR) located in Veracruz, Mexico. We set 18 camera traps to record medium and large-sized terrestrial mammals from August 2016 to January 2017. We calculated the trapping rate, guilds, and activity patterns of species. Diversity was estimated with Hill numbers. We compared our estimates with other studies in tropical forest in Mexico. We obtained 308 independent captures of 13 species; Cuniculus paca and Dasyprocta mexicana were the species with the highest trapping rate. Order-0, order-1, and order-2 diversity values were 13.99, 6.50, and 4.75 effective species, respectively, which ranks LTBR the fourth-most diverse reserve of medium- and large-sized terrestrial mammals compared to six other tropical rainforest sites in southern Mexico. We recorded mammals representing five trophic guilds, of which frugivore-folivores (five species) and omnivores (three species) ranked highest. All recorded species were primarily nocturnal (six species) or diurnal (six species). Tamandua mexicana, Leopardus pardalis, L. wiedii, and Eira barbara are listed as endangered in the Mexican Official Standard Norm NOM-059-2019, and L. wiedii is listed as near threatened in the IUCN Red List of Threatened Species. We were able to record 40.6 % of the terrestrial mammal species known to inhabit the LTBR. The absence of large-sized species such as large predators and herbivores was notable. Comparison of medium and large-sized mammal diversity of camera trapping studies in Mexico show that landscape degradation is impoverishing terrestrial mammal communities.

Simulated dynamics of southern cattle fever ticks (Rhipicephalus (Boophilus) microplus) in south Texas, USA: investigating potential wildlife-mediated impacts on eradication efforts

BackgroundCattle fever ticks (CFT), Rhipicephalus (Boophilus) annulatus and R. (B.) microplus, are vectors of microbes causing bovine babesiosis and pose a threat to the economic viability of the US livestock industry. Efforts by the Cattle Fever Tick Eradication Program (CFTEP) along the US-Mexico border in south Texas are complicated by the involvement of alternate hosts, including white-tailed deer (Odocoileus virginianus) and nilgai (Boselaphus tragocamelus).MethodsIn the present study, we use a spatially explicit, individual-based model to explore the potential effects of host species composition and host habitat use patterns on southern cattle fever ticks (SCFT, R. (B.) microplus) infestation dynamics and efficacy of eradication schemes.ResultsIn simulations without eradication efforts, mean off-host larval densities were much higher when cattle were present than when only white-tailed deer and nilgai were present. Densities in mesquite and meadows were slightly higher, and densities in mixed brush were much lower, than landscape-level densities in each of these scenarios. In eradication simulations, reductions in mean off-host larval densities at the landscape level were much smaller when acaricide was applied to cattle only, or to cattle and white-tailed deer, than when applied to cattle and nilgai. Relative density reductions in mesquite, mixed brush, and meadows depended on host habitat use preferences. Shifting nilgai habitat use preferences increasingly toward mixed brush and away from mesquite did not change mean off-host larval tick densities noticeably at the landscape level. However, mean densities were increased markedly in mesquite and decreased markedly in mixed brush, while no noticeable change in density was observed in meadows.ConclusionsOur results suggest that continued integration of field data into spatially explicit, individual-based models will facilitate the development of novel eradication strategies and will allow near-real-time infestation forecasts as an aid in anticipating and preventing wildlife-mediated impacts on SCFT eradication efforts.Graphical

High C-and N-based soil fertility and microbial associations sustain the plant biodiversity of the campo rupestre in Brazil

The campo rupestre vegetation in the Serra do Rola Moça State Park (PESRM) grows on ironstone outcrops, forming vegetation islands where plant species establish belowground interactions. This area is circumscribed by several mining companies and, for mined land rehabilitation purpose, we assessed plant species composition, plat-microbial associations, and soil fertility patterns in a preserved campo rupestre. Aside from high plant biodiversity, we found elevated soil fertility in relation to soil CEC (~18 cmol/dm3), organic matter (~115 g/Kg), soil C (~ 53.3 g/Kg), humic (~12.5 g/Kg) and fulvic (~8.9 g/Kg) acids, soil N (~4 g/kg) and a low C:N ratio (~12). The overall nutrient levels were higher than or comparable to those of other preserved sites in Brazil. The prevalent legume Mimosa calodendron, hosting N-fixing and plant growth-promoting bacteria in its nodules, was considered an N source to the soil, as evidenced by the elevated leaf N content and the greater depletion of leaf δ15N compared to other families. However, leaf N was parsimoniously distributed among biogeochemical islands and within different plant species and families, which was attributed to a common mycorrhizal network (CMN) formed by arbuscular (AMF) and orchid mycorrhizal fungi (OMF), suggested by general root mycorrhizal colonisation and soil phospholipid fatty acid (PLFA) analyses. We revealed that a high C- and N-based soil fertility constitutes a natural pattern of fertility, which is maintained by below-ground associations and is sufficient to sustain plant biodiversity. For rehabilitation purposes, this natural soil fertility of preserved sites should be maintained by integrating the biogeochemical relations involving plant communities and microbial associations.

Grassland management and land use history shape species composition and diversity in Transylvanian semi‐natural grasslands

AbstractAimsSemi‐natural grasslands are among the most biodiverse habitats in Europe, and they are of great conservation and agricultural value. However, changes in land use like grazing intensification and the cessation of traditional management have dramatic effects on the extent and biodiversity of these ecosystems. In this study we investigated how current management practices and land use history shape species composition and diversity patterns in semi‐natural grasslands of the Eastern hills of the Cluj region.LocationEastern hills of Cluj (“Dealurile Clujului de Est” ‐ ROSCI0295) Natura 2000 conservation site and close surroundings, Transylvania, Romania.MethodsWe surveyed plots in extensively and intensively grazed grasslands, grasslands mown by hand or heavy machinery, and abandoned grasslands. To quantify grassland continuity, we analysed a series of historical cadastral and more current maps ranging from the 18th to the 21st century.ResultsSpecies composition was significantly influenced by current management, grassland continuity and environmental factors. Mown and extensively grazed grasslands had more grassland and forest edge specialists than abandoned and intensively grazed grasslands. In addition, there was a positive relationship between the number of grassland specialists, forest edge species and grassland continuity, while the number of ruderal species related negatively to grassland continuity. The highest diversity values were recorded in traditionally mown grasslands. However, diversity‐related variables were poorly reflected by grassland continuity.ConclusionsThis study provides evidence that short‐term abandonment may not be as detrimental for grasslands as often suggested, and intensive grazing results in the greatest loss in species diversity. Grassland continuity tightly influences the persistence of grassland specialist species. Thus, we recommend land use history to be included in the selection and identification of high‐nature‐value grasslands by prioritizing conservation efforts for older grasslands.

On the floristic identity of Amazonian vegetation types

AbstractThe Amazon forest is far from uniform, containing different forest types and even savannas, but quantitative analyses of this variation are lacking. Here, we applied ordination analyses to test the floristic differentiation among Amazonian vegetation types using data for virtually all known tree species occurring in the Amazon (8224), distributed across 1584 sites. We also performed multiple regressions to assess the role of climate and substrate in shaping continental‐scale patterns of community composition across Amazonia. We find that the traditional classification of Amazonian vegetation types is consistent with quantitative patterns of tree species composition. High elevation and the extremes of substrate‐related factors underpin the floristic segregation of environmentally “marginal” vegetation types and terra firme forests with climatic factors being relatively unimportant. These patterns hold at continental scales, with sites of similar vegetation types showing higher similarity between them regardless of geographic distance, which contrasts with the idea of large‐scale variation among geographic regions (e.g., between the Guiana Shield and southwestern Amazon) representing the dominant floristic pattern in the Amazon. In contrast to other tropical biomes in South America, including the Mata Atlântica (second largest rain forest biome in the neotropics), the main floristic units in the Amazon are not geographically separated, but are edaphically driven and spatially interdigitated across Amazonia. Two thirds of terra firme tree species are restricted to this vegetation type, while among marginal vegetation types, only white‐sand forests (campinaranas) have a substantial proportion of restricted species, with other vegetation types sharing large numbers of species.

Soil fertility and anthropogenic disturbances drive mammal species richness and assemblage composition on tropical fluvial islands

AbstractFloodplain areas comprise some 30% of the area in the Amazon, but are currently under severe anthropogenic threat. Across the Amazon Basin, forest‐dwelling non‐volant mammals play crucial roles in maintaining the integrity of forest functionality, yet have been poorly studied in fluvial island forests. Mammal assemblages may be affected by edaphic characteristics that operate indirectly via food nutritional quality, by patch attributes, and/or can be modulated by anthropogenic disturbances. Here, we conducted systematic and quantitative mammal surveys across fluvial islands of an Amazonian archipelago, to assess the influence of edaphic factors (soil fertility), island attributes (island area and degree of isolation) and anthropogenic characteristics (distance from human settlement and logging) on the patterns of mammal species composition and richness. On 28 islands, we conducted spoor surveys and deployed 49 camera traps (total effort of 2940 camera trap‐days). Subsequently, we performed multiple regression analysis to investigate the influence of environmental and anthropogenic predictors on mammal species richness, while dbRDA (distance‐based redundancy analysis) was used for species composition. We found that mammal species richness was positively correlated with soil fertility, and in combination with anthropogenic characteristics, both variables affected the species assemblage composition. In particular, smaller species were found across a variety of levels of soil fertility and anthropogenic disturbances, while larger mammals were mostly recorded at sites with higher soil fertility and low levels of anthropogenic disturbances. Understanding the contribution of environmental and anthropogenic characteristics to the observed mammalian species richness and assemblage composition patterns will help optimise management and conservation efforts on Amazonian fluvial islands. In particular, we suggest enforcing hunting and logging restrictions within fluvial islands through surveillance activities, especially in more fertile islands.

Mapping the diversity of street tree inventories across eight cities internationally using open data

Tree diversity, on a species-, genus-, and family-level, is an important factor in securing healthy urban forests and providing ecosystem services for billions of city dwellers. Using open-source data on global tree inventories, this study examines (1) the diversity of species, genera, and family of urban street trees in eight cities internationally; (2) how they score on diversity benchmarks and indices; and (3) the diversity variation inside and outside of cities’ centers. We hypothesized most cities would score poorly on diversity benchmarks and spatial patterns in species composition would exist, as illustrated by established relationships between urban density and urban tree diversity. Results indicate city centers were less likely to approach the proposed diversity benchmarks than outside the city center. Overall, both Shannon and Simpson diversity indices show greater diversity outside of the city center, especially at the species-level. Understanding street tree diversity and spatial variation patterns across cities internationally can offer needed evidence to back up heuristic benchmarks. The methodology and open-source data used in this study are intended to enable practitioners better target tree diversity efforts.

Species composition and land use pattern of mosquito vector species in Sonitpur district, Assam

The risk of mosquito-borne diseases has put world under threat for long years. Many dependant variables, particularly physical and biological parameters of the breeding site directly influence the species richness and abundance patterns of mosquito species. The present study is an attempt to map the mosquito vector distribution in Sonitpur district of Assam, an endemic district in terms of mosquito borne diseases. Mosquito vectors are collected using CDC light traps from 21 different habitats along with their geographic coordinates. Geospatial technologies have been used for better interpretation of the mosquito distribution pattern. This study reveals that, the Anopheles and Culex mosquitoes are the dominant species. Malaria vectors are dominant in the northern part of the district due to the high extents of forest patches. Culex species is mainly distributed in the wetlands associated area and Mansonia species does not show affinity towards a particular habitat. Result of the study will be a significant endeavour in improving the scientific understanding and effective controlling the mosquito-borne diseases.