Estimates Of Species Richness Research Articles

Diversity of Zooplankton in the Rice Fields in Suphan Buri Province, Thailand, with a New Record of Cyclopoid Copepod

Rice fields are dynamic ecosystems with complex niche structures for organisms, and they have been hypothesised to have high biodiversity. Accordingly, in this study, the diversity of zooplankton in rice fields in Suphan Buri Province, a large area of rice plantations in the central region of Thailand, was examined. A total of 100 species, including 52 rotifers, 18 cladocerans, and 30 copepods, were recorded, including Mesocyclops kayi, which was a new record in Thailand. A high Simpson’s diversity index (0.63) and a low Pielou’s species evenness index (0.02) confirmed various potential niches for zooplankton in this ecosystem, leading to a low Jaccard similarity index both among the current rice fields and those in other regions. Moreover, the species richness estimators suggested that more species are expected to be discovered in the rice fields. Rotifer and copepod communities are influenced by local environmental variables, including dissolved oxygen, salinity, conductivity, and chlorophyll a. The results of this study fill a gap in the knowledge regarding the diversity and ecology of zooplankton in rice fields. However, further research is needed to fully comprehend the function of this ecosystem and the actual diversity in Thailand.

Biogeographic regionalization of the Amazon using highly diverse horse flies (Diptera: Tabanidae): insights from three decades of data

ABSTRACT Delimiting biogeographic regions based on occurrence data is an interesting approach to investigating processes behind biodiversity distribution patterns. Comparing spatial scales and identifying predictor variables of biogeographic regions have wide application for biodiversity conservation. In this study we used a comprehensive database containing more than thirty years of horse fly records to estimate species richness, endemism, and species composition, and regionalize the Amazon biogeographically. We compared five spatial scales defined by grid size (1–5º), and test five hypotheses (elevation, climate, vegetation cover, and two regionalizations from the literature) to identify predictors of the biogeographic regions. Endemism, species richness and composition were predicted by different sets of predictor variables, although the models were highly dependent on spatial scale. We identified three well-defined biogeographic regions, which have been formed by a combination of geographic distance, climate and historical factors converging with some theories proposed for mammals. Our models indicated dispersal as a key factor for regionalization, as it can be constrained by a combination of climate and historical processes changing habitats over time, although this finding was highly dependent on spatial scale. We showed that horse flies are interesting models for biogeography although they have been historically neglected.

Insect diversity in heterogeneous agro-environments of Central Europe

AbstractInsect diversity has been decreasing significantly during the past decades. A main driver causing this negative trend is agricultural intensification, which causes habitat destruction and a deterioration of habitat quality. We caught flying arthropods with 28 Malaise traps and two light traps across a heterogeneous Central European agro-environment in southern Germany over a period of four years. The arthropods captured with Malaise traps were assigned to barcode index numbers (BINs) based on metabarcoding. Lepidopterans caught with light traps and light towers were identified based on morphological characters. Within the four years study, a total of 11,984 insect operational taxonomic units (OTUs) related to unique BINs on BOLD (> 95% similarity) were recorded across this agro-environment. 7835 of them could be assigned to insect order and the vast majority of them represent different species. Different estimates of the total species richness ranged between 8188 and 11,512 OTUs (a proxy for species). This number corresponds to about 26–36% of the total German insect fauna. Light trapping also yielded a high species diversity and returned 502 Lepidoptera species (compared to 784 species captured with Malaise traps). The overlap between light and Malaise traps was less than 45%. The Malaise trap catches showed that insects are more diverse along forest edges than in the centre of meadows. Our findings underline the high value of heterogeneous agro-environments for biodiversity, and the high value when combining data collected with different sampling techniques.

Biogeographic patterns and environmental drivers of species richness in the globally distributed Millettioid/Phaseoloid clade (Fabaceae, subfamily Papilionoideae)

IntroductionThe Millettioid/Phaseoloid (MP) clade of Fabaceae is globally distributed, economically important, and highly diverse, making it an attractive system for studying biogeographic and macroecological patterns at a global scale. We conducted the first global macroecological study to map and explore the environmental drivers of the MP clade's species richness patterns.MethodsWe compiled 116,212 species occurrences (161 genera) for the MP clade and 20 environmental variables (19 bioclimatic variables and elevation). Geospatial analyses were performed to estimate species richness patterns and biogeographic heterogeneity. The effects of environmental variables on the species richness of the MP clade were measured through multiple regression models.ResultsOur study identified the megathermal regions as hotspots of species richness for the MP clade. While species distributions and richness largely fit the latitudinal diversity gradient pattern, there was a significant negative relationship between the species richness of the MP clade along the latitude and longitude. The Afrotropic biogeographic realm had the highest alpha diversity (~36%); in terms of biome types, tropical and subtropical moist broadleaf forests had the highest alpha diversity (25%), while the beta diversity revealed a high dispersal rate and habitat tracking. Furthermore, the species richness was positively influenced by multiple climatic factors, with the mean diurnal range of temperatures and precipitation in the warmest quarter having strongest influence.DiscussionOverall, the staggering species richness patterns could be explained by multiple diversity gradient hypotheses. Particularly, colder climates play a crucial role in shaping the species richness pattern by limiting the ecological opportunities for MP clade species in the higher latitudes of the Northern Hemisphere. This suggests that the species richness patterns of the MP clade can be described as "when dispersal meets adaptation." Our study provides a new basis for identifying priority regions for conservation of legumes.

Extending the conservation impact of great ape research: Flagship species sites facilitate biodiversity assessments and land preservation.

To inform regional conservation planning, we assessed mammalian and avian biodiversity in the Djéké Triangle, which is an intact forest with long-term research and tourism focused on western lowland gorillas (Gorilla gorilla gorilla). This critical region serves as a conservation conduit between the Nouabalé-Ndoki National Park (NNNP) in the Republic of Congo and the Dzanga-Ndoki National Park in Central African Republic. Wildlife inventories were conducted to determine if biodiversity in the Djéké Triangle (initially part of a logging concession) was equivalent to the NNNP. Camera traps (CTs) were deployed to estimate species richness, relative abundance, naïve occupancy, and activity patterns of medium-to-large species in mixed species and monodominant Gilbertiodendron forests that comprise the majority of regional terra firma. Species inventories were collected from CTs positioned on a grid and at termite nests throughout the Djéké Triangle and compared to CTs placed in the Goualougo Triangle located within the NNNP. From 10,534 camera days at 65 locations, we identified 34 mammal and 16 bird species. Allaying concerns of wildlife depletion, metrics of species richness in the Djéké Triangle surpassed those of the Goualougo Triangle. Many species were observed to occur across habitats, while others showed habitat specificity, with termite mounds indicated as an important microhabitat feature. Our comparisons of animal activity budgets in different habitat types provide important reference information for other populations and contexts. In conclusion, this study provided empirical evidence of the high conservation value of this region that contributed to increasing the protected status of the Djéké Triangle.

Evaluating the efficiency of different sampling techniques to survey non-flying small mammals in the Amazon

AbstractSmall non-flying mammals represent 44% of Brazilian mammal species and have a wide range of habits and life-history strategies. This wide diversity requires different sampling methods in survey studies. We compared the efficiency of pitfall and live-traps in different vertical positions in relation to the alpha and beta diversity of small mammals in three forest fragments with different levels of conservation and in a continuous area in the southwestern Amazon, Acre state. Captures were carried out using a combination of pitfall traps and live-traps on the ground, understorey, and canopy. Taxonomic identification was performed by morphological and molecular analyses. Alpha diversity was evaluated using Hill numbers (q = 0 and q = 1). The turnover between different types of traps and different vertical strata (beta diversity) was analysed using permutation analysis of variance. Species richness between areas ranged from 6 to 21. The highest species richness was observed in ground traps, and the lowest species richness was observed in the canopy. Live-traps on the ground recorded a greater diversity in two areas. Pitfall traps recorded the greatest number of unique species in three areas. The different types of traps and the different vertical positions acted in a complementary way in the small mammal samplings. The turnover in relation to trap type and stratum indicated the formation of two significantly different groups: ground traps and aboveground traps. However, the use of canopy traps did not contribute significantly to an increase in the estimated species richness and diversity in three of the four localities.

BIRD DIVERSITY ACROSS AN ANDEAN CITY: THE LIMITATION OF SPECIES RICHNESS VALUES AND WATERSHED SCALES

Evaluating several biodiversity descriptors and considering several spatial scales might elucidate conservation issues and improve biodiversity monitoring in urban environments. We estimated species richness (order q = 0), Shannon diversity (order q = 1), and Simpson diversity (order q = 2) based on Hill numbers and performed cluster analysis and non-metric multidimensional scaling (NMDS) to compare seven urban micro-watersheds and a peri-urban site across a northern Andean city (Medellín, Colombia). We found 113 diurnal resident bird species: 50 (44 %) exclusively within urban sites, 21 (19 %) exclusively in the periurban site, and 42 (37 %) shared species. Some urban watersheds had similar bird species richness to the periurban site, but Shannon and Simpson diversities were always lower, showing decrease in local bird diversity when abundances were considered. Bird species composition differed between urban watersheds and the periurban site, with all urban watersheds grouped altogether by cluster and NMDS analysis, and the periurban site forming its own group. This suggests homogenization of bird species composition due to the species turnover decreasing across urban areas, with endemic, near endemic and rare species restricted to periurban areas where native forest remnants persist. Several scales of biodiversity and analysis at more local scales are needed to better understand biodiversity patterns across Andean cities and to design urban planning strategies that prevent biodiversity loss.

High‐throughput metabarcoding of SAR11 assemblages from the southwest Atlantic shelf and arid Patagonia: richness and associated rank abundance distributions

The SAR11 clade is likely the most abundant microbial lineage on earth. Here, we provide detailed analyses of the group’s richness and AD in poorly studied Southern microbiomes. This requires whole community composition analyses to be performed, which are also provided in conjunction with the SAR11‐specific studies. In this way, the work describes unknown aspects of the diversity of an outstanding bacterial lineage and novel data on remote and relatively little‐studied microbial communities.BackgroundMassively parallel sequencing of environmental DNA allows microbiological studies to be performed in greater detail than was possible with first‐generation sequencing. For example, it facilitates the use of approaches hitherto largely applied to flora and fauna, such as rank abundance distribution (RAD) analyses.MethodsHere, we set out to advance the knowledge on Ca. Pelagibacterales (SAR11) communities from southern South America using environmental sequences from the open ocean in the Argentine sea, the uncharted Engaño Bay, as well as a river and an oligohaline shallow lake from the Patagonian Steppe ecoregion. The structures of the SAR11 assemblages present in these ecosystems were dissected by direct and rarefaction‐based estimates of species richness, and evaluations of the corresponding abundance distributions (ADs), which was addressed by RAD analyses.ResultsMicrobial community composition analyses revealed that the studied SAR11 assemblages coexist with 27 bacterial phyla. SAR11 richness was in general very high, but ADs turned out to be highly uneven. The results were compatible with prior knowledge, and similar to that derived from point estimates of diversity. However, our comprehensive dissection allowed for more detailed quantitative comparisons to be made between the environments surveyed, and revealed differences regarding both richness and the underlying ADs.ConclusionsDespite SAR11 assemblages being extremely rich, their ADs are very uneven. Richness and ADs can vary, not only between fresh and salt water, but also between oceanic and coastal marine environments. The obtained results provide insights on general topics such as adaptation and the contrast between marine and freshwater radiations.

Oral Porphyromonas gingivalis infection affects intestinal microbiota and promotes atherosclerosis.

The link between periodontitis and intestinal dysbiosis, two factors that contribute to atherosclerosis, has not been clearly defined. We investigated the integrative effects of oral infection with Porphyromonas gingivalis (PG), the major pathogen for periodontitis, on intestinal microbiota and atherosclerosis. ApoE-/- mice were fed a normal chow diet (NC), a Western diet (WD) or a WD with oral PG infection (PG). The PG infection was investigated by placing a total of 109 CFUs of live PG into the oral cavity of each mouse using a feeding needle five times a week for 3 weeks. Atherosclerotic lesions of the aortae were measured, and blood lipoproteins and the expression of molecules related to lipid metabolism in the liver were analysed. We also performed 16S RNA sequencing and a microbiome analysis using faeces. En face bloc preparation of the aortae showed that the PG group had a 1.7-fold increase in atherosclerotic lesions compared with the WD group (p < .01). Serum analyses showed that oral PG infection induced a significant decrease in high-density lipoprotein (HDL) and triglyceride. Western blots of hepatic tissue lysates revealed that PG infection reduced the expression of scavenger receptor class B type 1 (SR-B1) in the liver by 50%. Faecal microbiota analysis revealed that species richness estimates (Chao1, ACE) decreased immediately after PG infection. PG infection also induced a significant decrease in Shannon diversity and an increase in Simpson's indices in the WD-fed mice. PG infection significantly increased the phyla Actinobacteria and Deferribacteres, along with the species Mucispirillum schaedleri and Lactobacillus gasseri, in the mice. The functional study showed that PG infection increased the expression of proteins that function in carbohydrate and glucose metabolism, including phosphotransferase system (PTS) proteins and the GntR family transcriptional regulator. Oral PG infection promotes atherosclerosis and induces significant metabolic changes, including reduced serum HDL and reduced hepatic SR-B1 and ABCA1 expression, as well as changes in intestinal microbiota. Our study suggests that intestinal dysbiosis accompanies periodontitis and could play a role in atherosclerosis.

Diversity of free-living flatworms (Platyhelminthes) in Cuba

Abstract Cuban biodiversity is characterized by high species richness and endemism; however, free-living flatworms have been neglected in studies of the fauna of the archipelago. These animals constitute an essential component of marine and freshwater ecosystems as top predators and secondary producers. In this contribution, we provide the first comprehensive analysis of turbellarian diversity in Cuba based on a long-term sampling effort in marine, brackish, freshwater and terrestrial environments. We used observed and estimated species richness as indicators of alpha diversity. As a result, we have collected, for the first time, 279 species in Cuba, including 189 species of rhabdocoels, 33 species of polyclads, 21 species of macrostomorphs, 14 species of proseriates, 12 species of prolecithophorans, seven species of triclads and one representative each of Prorhynchida, Gnosonesimida and Bothrioplanida. At least 184 species (67%) are new to science. Fifty of these species have been recorded in published journal contributions. The remainder are pending formal identification and/or description. We demonstrate the turbellarian fauna of Cuba to be one of high diversity and endemism. Estimated species richness is much higher than that observed, exemplifying the taxonomic impediments and stressing the need for more intense sampling campaigns in the archipelago.

Effectiveness of rapid sampling assessments for wetland-breeding amphibians

A primary response to the Clean Water Act has been the development of numerous indices of biotic integrity (IBI) using various taxonomic groups to assess the condition of water bodies in the United States. The IBI is a frequently used approach for assessing the ecological integrity of streams; however, it is less commonly applied to wetland systems, despite the scientific and policy needs to assess wetland condition and develop ecological performance goals for wetland monitoring, creation, and restoration. Although a great deal of attention has been given to wetland acreage due to the “no net loss” policy over the past two decades, much less attention has been given to the ecological integrity of these same wetlands. To assess wetland health and function, regulatory agencies and land managers need clear performance standards that are based on the ecology of wetland organisms. To address this need, we sampled 242 wetlands distributed across 45 managed properties in Illinois, U.S.A. over three years (2012–2014) for adult and larval amphibians (12 samples per wetland). Amphibian assemblages make up critical ecological components of many wetland ecosystems and are considered useful bioindicators of environmental change because they are sensitive to various forms of environmental and habitat alteration. We developed an amphibian-based IBI (hereafter aIBI) for the assessment of seasonal wetlands and optimal sampling strategies to best quantify these wetlands (i.e., assessment of time and effort). The aIBI applied a conservation coefficient to all species captured; conservation coefficients were developed through a survey of amphibian experts (n = 16). We captured 25 amphibian species with an average of 7.11 amphibian species (range 1–13) per site. Using the species occurrence data collected from both dipnet and minnow trap surveys over 12 survey periods, we assessed the average percent error in the estimation of aIBIs and species richness. Our results show that a wetland can be accurately evaluated with amphibians in one field season, but that multiple samples during that field season will be necessary. We show that 4–5 surveys using multiple methods distributed throughout the spring and summer are required. This level of effort may be incongruent with existing definitions of ‘rapid assessment’, but it is the necessary level of effort needed to confidently and accurately evaluate wetlands using amphibians as an indicator taxon. Additionally, aIBI provides a more robust framework to assess wetland integrity compared to simple species richness or other similar methodologies.

Poor performance of acoustic indices as proxies for bird diversity in a fragmented Amazonian landscape

Biodiversity loss is rampant worldwide, particularly in tropical regions like the Amazon. In the last decade, acoustic indices have been proposed as a rapid method for biodiversity assessment. However, their overall effectiveness as proxies for biodiversity is under debate. Here, we tested advanced statistical methods based on acoustic indices recently proposed to estimate species richness more accurately. Using an annotated audio dataset (2356 one-minute files) and song characterization of tropical bird assemblages from land-bridge islands in an Amazonian hydroelectric reservoir, we fitted both regression models and random forest algorithms to address the following questions: (1) do acoustic indices provide accurate estimates of bird species richness? (2) are univariate (a single index) or multivariate models (a combination of indices) better at predicting species richness? (3) at what temporal scale (minutes or hours) and with which measures (raw values or mean and standard deviation values)? (4) do these indices reflect spatial (island size) and temporal patterns (diel cycle) of singing activity? Although we found that multivariate models using a set of acoustic indices computed at a broader scale (hours) performed better than simpler models, their overall predictive power of species richness was poor for these tropical bird assemblages. The high heterogeneity and variation in the acoustic activity and signals of the Amazonian bird species present a considerable challenge for acoustic indices to capture changes in species diversity adequately. In agreement with recent studies, our findings point out the limits of acoustic indices, especially in tropical, highly diverse regions, emphasizing that caution should be used when applying this type of acoustic indices in biodiversity assessment. In contrast, all tested indices reflected distinct spatial and temporal patterns that were often related to habitat features (i.e. island size) and animal activity (i.e. choruses), supporting alternative (large-scale) applications of acoustic indices. Random forest algorithms confirmed the potential to classify island size based on soundscape characteristics. These findings suggest acoustic indices can capture differences in assemblage composition and bird activity along a habitat fragmentation gradient. Hence, they can more efficiently assess habitat and community structure than species diversity, occurrence, or abundance.

The efficacy of performing field surveys during the dry and rainy seasons to estimate species richness and composition of local bat assemblages

AbstractHere we assessed the efficacy of performing field surveys during both dry and rainy seasons to estimate species richness and composition of phyllostomid bats in 12 sites of the Brazilian Atlantic Forest. Our goal was to elucidate two opposite scenarios. If bat species compositions differ between the dry and rainy seasons, then field surveys in both seasons will be considered complementary for estimating local bat assemblages. In contrast, if bat species compositions in the dry season are a nested subset of the species present in the rainy season, then field surveys in both seasons will be considered redundant. Our results showed that field surveys performed only during the rainy season exhibited the same efficacy in recording bat species as field surveys considering both dry and rainy seasons combined. Consequently, the rare species sampled in the rainy season contributed to the uniqueness of communities in terms of species composition. Considering that time, funding, and the number of field personnel available for work are important factors when determining the sampling effort in highly biodiverse regions like the tropics, our results can be useful in establishing protocols for research projects with limited resources aiming to create a comprehensive list of species.

Enhancing semi-aquatic species representativeness beyond protected areas: dragonflies in networks of conservation corridors

Complementarity is crucial when prioritizing sites for biodiversity conservation. Networks of conservation corridors (CCs) can contribute to regional representativeness by complementing biodiversity features included in existing protected areas (PAs). We ask whether criteria important for CC management and design are effective at prioritizing complementary sites, and how the consideration of species represented in PAs influence criteria performance. We focused on species turnover of generalist and specialist dragonflies across 88 riverine sites. Criteria assessed included site-level estimates of dragonfly species richness, estimates of local habitat quality and corridor width. Measures of local habitat quality were based on either dragonfly indicator species or proportion of alien vegetation. Results showed that CCs complement dragonfly diversity in PAs by contributing unrepresented generalist species. Of the criteria, corridor width was the most efficient at prioritizing complementary sites, while prioritization based on dragonfly indicator species or species richness underperformed. When aiming to prioritize CC sites that also complement sites situated in established PAs, wide corridors with low levels of alien vegetation should be favoured.

The relationship between naturalized alien and native plant species: insights from oceanic islands of the south-east Pacific over the last 200 years

Aim: The relationship between native and naturalized alien species has been widely studied, particularly across large geographic scales. However, our knowledge of the spatial and temporal variations of their relationships is still limited, particularly for remote oceanic islands such as those of the south-east Pacific and across islands and archipelagos. In this study, we aim to assess the relationships between native and naturalized alien species by analyzing their current patterns of species-area relationships at different spatial scales, in addition to temporal variations in species richness, over the last 200 years.Area: One island (Rapa Nui) and two archipelagos (Juan Fernandez and Desventuradas Islands) comprising a total of 11 oceanic islands of the south-east Pacific (OISEP).Methods: We assembled the most comprehensive dataset of the vascular flora of the OISEP from currently available island flora checklists and updated with recent publications. Each plant species was classified as being native or naturalized alien. We examined temporal changes by estimating species richness, naturalization rates and naturalized-to-native ratios over time based on the first collection year of each naturalized alien species. Then, we determined the best shape of naturalized alien species richness accumulation over time by contrasting the fit of lineal, exponential, sigmoidal and Weibull regressions. Finally, we analyzed the relationships between native and naturalized species firstly at the inter-archipelagic scale by fitting island species-area relationship models and secondly at the island scale by performing ranged major axis regression analysis on residual values.Results: The OISEP flora dataset contained 674 species of which 282 were native and 392 were naturalized alien. Native island species-area relationships were similar to those of the naturalized alien species. Naturalized alien species richness increased notably through time with two clear peaks in 1950 and 2000. A Weibull regression and an exponential shape over time were the most appropriate fits for naturalized alien species richness accumulations at the inter-archipelagic scale, which further emphasizes the notable increase in naturalized alien species richness experienced in the timeframe examined here.Main conclusions: The relationship between naturalized alien species richness and native species richness was found to be independent of the geographic scale. The number of naturalized alien species clearly exceeded the number of native species on most islands but also for the whole OISEP. The accumulation of newly detected naturalized alien species does not show any sign of saturation and it is likely that new species will arrive in the future. Increased efforts on monitoring, prevention and biosecurity are needed to halt biological invasions on these unique island ecosystems.

Global biogeographical patterns of ants and their abiotic determinants

Abiotic determinants of global biogeographical patterns are well known for a range of taxa, particularly plants and vertebrates. However, they are largely undescribed for most arthropods which constitute the bulk of the world biodiversity. Based on recently updated ant databases, we estimate the relative strength of abiotic and topographic determinants of ant species richness at the global scale, and investigate how such determinants vary across zoogeographic realms. We used ant species distribution to estimate ant species richness, the number of sampling points, and estimated species richness per cell of 2° worldwide. We fit simultaneous autoregressive models (SAR) to test the relative importance of six explanatory variables: annual rainfall, rainfall seasonality, mean temperature, actual evapotranspiration, mean altitude, and topographic heterogeneity, on estimated species richness. At the global scale, estimated ant species richness was best explained by annual rainfall and mean temperature. However, while annual rainfall affected positively estimated species richness for most realms, the sign of the mean temperature varied between realms. Furthermore, rainfall seasonality, actual evapotranspiration, mean altitude and topographic heterogeneity affected negatively estimated ant species richness in a number of realms. The variation in ant diversity determinants between realms challenges the generality of the global pattern and demonstrates the importance of regional ecological and historical settings. This provides useful information for conservation planning and helps predict how ants will respond to global and regional climate change.

Insect collecting bias in Arizona with a preliminary checklist of the beetles from the Sand Tank Mountains.

The State of Arizona in the south-western United States supports a high diversity of insects. Digitised occurrence records, especially from preserved specimens in natural history collections, are an important and growing resource to understand biodiversity and biogeography. Underlying bias in how insects are collected and what that means for interpreting patterns of insect diversity is largely untested. To explore the effects of insect collecting bias in Arizona, the State was regionalised into specific areas. First, the entire State was divided into broad biogeographic areas by ecoregion. Second, the 81 tallest mountain ranges were mapped on to the State. The distribution of digitised records across these areas were then examined.A case study of surveying the beetles (Insecta, Coleoptera) of the Sand Tank Mountains is presented. The Sand Tanks are a low-elevation range in the Lower Colorado River Basin subregion of the Sonoran Desert from which a single beetle record was published before this study. The number of occurrence records and collecting events are very unevenly distributed throughout Arizona and do not strongly correlate with the geographic size of areas. Species richness is estimated for regions in Arizona using rarefaction and extrapolation. Digitised records from the disproportionately highly collected areas in Arizona represent at best 70% the total insect diversity within them. We report a total of 141 species of Coleoptera from the Sand Tank Mountains, based on 914 digitised voucher specimens. These specimens add important new records for taxa that were previously unavailable in digitised data and highlight important biogeographic ranges.Possible underlying mechanisms causing bias are discussed and recommendations are made for future targeted collecting of under-sampled regions. Insect species diversity is apparently at best 70% documented for the State of Arizona with many thousands of species not yet recorded. The Chiricahua Mountains are the most densely sampled region of Arizona and likely contain at least 2,000 species not yet vouchered in online data. Preliminary estimates for species richness of Arizona are at least 21,000 and likely much higher. Limitations to analyses are discussed which highlight the strong need for more insect occurrence data.

Uneven species occurrence and richness of lowland snakes (Serpentes, Squamata) in Terengganu, Peninsular Malaysia, with new locality records.

This study documents information on the composition, diversity, richness, and temporal occurrence of snakes at Sekayu's lowland forest (SLF), Terengganu, Peninsular Malaysia for the first time. The snakes recorded within the SLF were sampled opportunistically from 2013 to 2019, employing the Visual Encounter Survey method (VES) and L-shape pitfall traps with drift fences. Forty-six snake species from 37 genera belonging to the nine families were recorded, of which 11 were new records to Terengganu. Individual-based rarefaction and extrapolation curves were not reaching asymptote, indicating that additional species can be recorded at the study area. Non-parametric species richness estimators estimated and produced a range between 51 and 57 species. ACE was the best estimator based on the quantitative evaluation. All species showed some variations of occurrence patterns across months. Fourteen species were only encountered once across the sampling years, and interestingly 11 of them were only detected during the rainy season (late October to January). In general, the number of species richness, abundance, and rare species were high during this season. Species richness of snakes is high at SLF but sampling effort should be intensified, especially during these rainy months, to obtain a robust estimated snake species richness in SLF. Terengganu harbor considerably high species richness of snakes with a total of 71 species to date (excluding marine snakes), but snake diversity is still underestimated as only a few localities were surveyed in the past years, primarily at the northern part. Future surveys should be commenced at the central and southern parts of Terengganu to complement the current investigation.

Difficult times for amphibians: Effects of land-use change at the local and landscape scales in the Iberá Wetlands

Land-use change and management practices have led to habitat loss, one of the greatest factors in biodiversity decline. Particularly, amphibians comprise the highest number of threatened vertebrate species at the global scale. In this work, amphibian communities were analysed in three differing landscapes: a protected wetland, a livestock-impaired rangeland and a pine afforestation. In each landscape, amphibian species were sampled. Land-cover type and composition, as well as primary vegetation types were characterised at the landscape and local scale, respectively. The relationship between these environmental variables and the amphibian communities was analysed. Twenty-one amphibian species were identified; the protected and afforested landscapes were the richest, whereas the rangeland showed the lowest species richness and diversity estimates. At the local scale, vegetation, water coverage and land-use category explained the higher presence of amphibian species and their abundance. These results show how different land-uses, especially livestock farming, modify the composition of amphibian communities. This work constitutes a foundation for the development of sustainable management practices for conserving amphibians in landscape-level altered habitats.

Fish species richness is a key predictor of community biomass and productivity in littoral regions of Severn Sound, an embayment of southern Georgian Bay, Lake Huron

Catches from standardized littoral electrofishing (EF) surveys (1990–2016) at various locales in Severn Sound, Georgian Bay, were analyzed. Catches were adjusted for size-selectivity using published results of laboratory immobilization experiments. Adjusted abundance-mean size relationships were consistent with the metabolic theory of ecology where body size has a central role in structuring community features. Relationships among species richness and areal estimates of biomass and annual production of the adjusted catches were assessed. Richness was the key variable driving other community metrics and was, in turn, largely driven by habitat fetch metrics and sampling time of day. Richness, biomass, and production decreased with increasing maximum effective fetch. Richness increased with time after sunset. Year and locale had smaller roles in variation of community metrics with more vegetated/ less urbanized areas having higher values. Higher fish production is expected in sheltered areas where the contributions of allochthonous and benthic primary production are expected to be greater. Further analyses using additional EF datasets from Great Lakes’ littoral zones should increase understanding of the differences between littoral and offshore fish productivity and help guide management of littoral habitats to ensure healthy fish communities.