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The correlates of mammal species richness and community associations along elevation gradients have resulted in conflicting results within tropical systems. We surveyed the terrestrial mammal and gallinaceous bird community (>200 g body size) along transects at 4 mountain sites in Malaysian Borneo using camera traps to assess structuring of the mammal community along the elevation gradient. Between 2015 and 2021, we surveyed Bukit Lanjak (elevation 1,300 m) in Sarawak (Lanjak Entimau Wildlife Sanctuary; LEWS) and Mts. Kinabalu, Tambuyukon, and Magdalena (up to 2,400 m) in Sabah, with a total sample effort of 20,600 camera nights. We detected 48 species of mammals and 9 species of large terrestrial birds. There was mostly a common species pool across the sites, with only 9 species detected solely in LEWS and 5 species only in Sabah. Over our limited elevation range, no species were detected across the entire elevation range and no common species were confined to the highest elevation sites in Sabah or LEWS (>1,000 m). A species richness curve for each location indicated a slight peak at ~1,000 m for LEWS, but the mid-elevation peak was not evident at Sabah. The individual response curves of relative abundance to the elevation gradient for 15 species with sufficient detections were similar across sites (1 exception—Malaysian Porcupine) with 6 species showing no correlation with elevation, while 4 species increased and 4 species decreased in detections with elevation. A multivariate analysis of species detections found herbivores at lower elevations and mesocarnivores at higher elevations, while species of the same foraging guilds differed in body size at the same elevation. As opposed to studies focused on smaller vertebrate species (i.e. rodents, songbirds), larger mammal and terrestrial bird communities in these mountains did not form unique communities along the elevation gradient but did structure according to the functional traits of foraging guilds and body size. [ABSTRACT FROM AUTHOR]

Nonstructural carbohydrates (NSC) are essential for tree growth and adaptation, yet our understanding of the seasonal storage and mobilization dynamics of whole-tree NSC is still limited, especially when tree functional types are involved. Here, Quercus acutissima Carruth. and Pinus massoniana Lamb, with distinct life-history traits (i.e. a deciduous broadleaf species vs an evergreen coniferous species), were studied to assess the size and seasonal fluctuations of organ and whole-tree NSC pools with a focus on comparing differences in carbon resource mobilization patterns between the two species. We sampled the organs (leaf, branch, stem and root) of the target trees repeatedly over four seasons of the year. Then, NSC concentrations in each organ were paired with biomass estimates from the allometric model to generate whole-tree NSC pools. The seasonal dynamics of the whole-tree NSC of Q. acutissima and P. massoniana reached the peak in autumn and summer, respectively. The starch pools of the two species were supplemented in the growing season while the soluble sugar pools were the largest in the dormant season. Seasonal dynamics of organ-level NSC concentrations and pools were affected by organ type and tree species, with above-ground organs generally increasing during the growing season and P. massoniana roots decreasing during the growing season. In addition, the whole-tree NSC pools of P. massoniana were larger but Q. acutissima showed larger seasonal fluctuations, indicating that larger storage was not associated with more pronounced seasonal fluctuations. We also found that the branch and root were the most dynamic organs of Q. acutissima and P. massoniana , respectively, and were the major suppliers of NSC to support tree growth activities. These results provide fundamental insights into the dynamics and mobilization patterns of NSC at the whole-tree level, and have important implications for investigating environmental adaptions of different tree functional types. [ABSTRACT FROM AUTHOR]

Background and Aims The quartz fields of the Greater Cape Floristic Region (GCFR) are arid and island-like special habitats, hosting ~142 habitat-specialized plant species, of which 81 % are local endemics, characterized by a rapid turnover of species between and among sites. We use several phylogenetic community metrics: (1) to examine species diversity and phylogenetic structure within and among quartz fields; (2) to investigate whether quartz field specialists are evolutionarily drawn from local species pools, whereas the alternative hypothesis posits that there is no significant evolutionary connection between quartz field specialists and the local species pools; and (3) to determine whether there is an association between certain traits and the presence of species in quartz fields. Methods We sampled and developed dated phylogenies for six species-rich angiosperm families (Aizoaceae, Asteraceae, Crassulaceae, Cyperaceae, Fabaceae and Santalaceae) represented in the quartz field floras of southern Africa. Specifically, we focused on the flora of three quartz field regions in South Africa (Knersvlakte, Little Karoo and Overberg) and their surrounding species pools to address our research questions by scoring traits associated with harsh environments. Key Results We found that the Overberg and Little Karoo had the highest level of species overlap for families Aizoaceae and Fabaceae, whereas the Knersvlakte and the Overberg had the highest species overlap for families Asteraceae, Crassulaceae and Santalaceae. Although our phylogenetic community structure and trait analyses showed no clear patterns, relatively low pairwise phylogenetic distances between specialists and their local species pools for Aizoaceae suggest that quartz species could be drawn evolutionarily from their surrounding areas. We also found that families Aizoaceae and Crassulaceae in Knersvlakte and Little Karoo were phylogenetically even. Conclusions Despite their proximity to one another within the GCFR, the studied areas differ in their species pools and the phylogenetic structure of their specialists. Our work provides further justification for increased conservation focus on these unique habitats under future scenarios of global change. [ABSTRACT FROM AUTHOR]

Background and Aims Islands, with their long coastlines and increased vulnerability to sea level rise, offer compelling opportunities to investigate the salinity tolerance of coastal plants. Seeds are generally more vulnerable than other plant stages to increased stressors. The aim of this study was to characterize salinity tolerance during germination across a diverse pool of 21 species from 14 plant families found in coastal communities throughout the Hawaiian Islands in order to increase our general understanding of coastal plant ecology for conservation and restoration. Methods Seeds of each species were exposed to unfiltered/untreated seawater (35 ppt total salinity) and two salinity treatments (10 and 20 ppt) in which the seawater was diluted with distilled water, and germination percent and timing were compared to seeds in a distilled water control. Non-germinated seeds were then tested for recovery germination. We quantified and compared germination percent, time and recovery among species and across salinity levels and tested for heterogeneity related to seed size, dormancy class, habit and threatened status. Key Results Although salinity tolerance varied considerably among species, salinity exposure generally reduced and delayed germination. The greatest effects were detected at higher salinity levels. Recovery germination overall was higher for seeds that had been exposed to higher salinity. None of the factors we explored emerged as predictors of salinity tolerance except seed mass, which tended to enhance germination at higher salinity. Conclusions Species responses to salinity exposure indicate high vulnerability of coastal systems to increased salinity stress, and variability among species could lead to shifts in community assembly and composition under sea level rise. These results can help guide coastal ecosystem conservation and restoration management decisions in the face of climate change. [ABSTRACT FROM AUTHOR]

Branchinecta serrata Rogers, 2006 was originally thought to be limited to four localities in the central USA. We present new records of this species in prairie pools in central Canada, greatly extending its known distribution. Previous records from Canada were misidentified as the common and widespread B. paludosa (Müller, 1788). We present images emphasizing the differences between the two species, updated geochemical tolerance data, and revise the conservation status of B. serrata. Finally, we present an identification key to the Branchinecta paludosa species group. [ABSTRACT FROM AUTHOR]

The biotas of Taiwan and Hainan Islands are of continental origin, but the manner with which historical and ecological factors shaped these insular species is still unclear. Here, we used freshwater fish as a model to fill this gap by quantifying the phylogenetic structure of the insular faunas and disentangling the relative contribution of potential drivers. Firstly, we used clustering and ordination analyses to identify regional species pools. To test whether the insular freshwater fish faunas were phylogenetically clustered or overdispersed, we calculated the net relatedness index (NRI) and the nearest taxon index (NTI). Finally, we implemented logistic regressions to disentangle the relative importance of species attributes (i.e. maximum body length, climatic niche dissimilarity [ND], and diversification) and historical connectivity (HC) in explaining the insular faunas. Our results showed that the most possible species pools of Taiwan are Zhejiang and Fujian provinces, and those of Hainan are Guangdong and Guangxi provinces. These insular faunas showed random phylogenetic structures in terms of NRI values. According to the NTI values, however, the Taiwanese fauna displayed more phylogenetic clustering, while the Hainanese one was more overdispersed. Both the standard and phylogenetic logistic regressions identified HC and climatic ND as the 2 top explanatory variables for species assemblages on these islands. Our reconstruction of the paleo-connected drainage basins provides insight into how historical processes and ecological factors interact to shape the freshwater fish fauna of the East Asian islands. [ABSTRACT FROM AUTHOR]

We analyzed phytoplankton biodiversity trends in a 52 year (1967–2018) monitoring time-series from the archipelago of Helsinki, Gulf of Finland, the Baltic Sea. The community ordination revealed strong ordering of samples along the time axis (generalized additive model—gam fit: R 2 = 0.9). Species richness increased in time and was the most influential alpha diversity descriptor related to the community structure (gam fit: R 2 = 0.56–0.70). Changes in species richness accounted for 35–36% of the mean between-sample beta diversity. The remaining 64–65% was due to species turnover—the dominant component of the biodiversity trend. The temporal beta diversity trend reflected the eutrophication history of the geographically confined region, with a turning point in mid-1990s demarking the adaptation and recovery phases of the phytoplankton community. Trends in spatial beta diversity revealed homogenization of the communities in the outer archipelago zone, but not in the inner bays. The temporal decay of community similarity revealed high turnover rate, with 23.6 years halving time in the outer archipelago and 11.3 years in the inner bays, revealing the differences in eutrophication strength. The observed phytoplankton trends manifest the regional eutrophication history, and dispersal of new species to the unsaturated brackish species pool. [ABSTRACT FROM AUTHOR]

Background and Aims The defensive role of spines has previously been related to leaves, young shoots and reproductive organs. However, some woody species harbour spines on their trunks where none of those organs are present. Several explanations are plausible: they could be (1) climbing aids, (2) remnants from defence of leaves or reproductive organs during an earlier development phase, or (3) an as-yet undescribed defence. Here we investigate whether they could play a role against either bark feeding or preventing climbing animals accessing food resources in the tree canopy. Methods We described 31 woody species with spines on their trunk, growing in a botanical garden, to test whether morphological strategies could be identified and suggest what could be their most likely function. As testing their function is difficult experimentally for large pools of species, we performed virtual experiments to evaluate the potential roles of trunk spines against bark removal and climbing animals of different sizes. We then compared for each species and their confamilial non-spiny species the nutritional profiles of leaf, bark and reproductive organs to test whether trunk spines were associated with a nutritious organ (more likely targeted by herbivores). Key Results We identified four morphological syndromes of trunk spines. Two corresponded to already known functions (anchorage for lianas and crown defence against large ground mammals), and two strategies are newly described trait syndromes with traits suggesting a defence against bark feeding and climbing mammals. By simulation, we show how each strategy could translate into defence against debarking and prevent herbivores from climbing. Conclusions We identified trunk spine strategies and the criteria to classify them, their most likely function and the likely feeding mode and size of animal against which different trunk spine strategies may be effective. We discuss further perspectives for testing their function and their ecological significance. [ABSTRACT FROM AUTHOR]

We characterized the functional and taxonomic composition of the active and dormant communities from perennial lagoons and temporary ponds in a coastal plain. We sought to determine the degree of coherence between the egg bank and the active community within the same type of environment (temporary or perennial) and between environments subject to different hydrological cycles. We sampled the zooplankton community and environmental variables in six temporary ponds and five perennial lagoons in the dry and the wet periods of the hydrological cycle. Temporary ponds and perennial lagoons differed in abiotic conditions, with higher values of dissolved carbon in temporary ponds and higher values of salinity in perennial lagoons. The taxonomic coherence between active and dormant communities in temporary environments was greater than in perennial environments. In functional terms, we observed a high coherence between active and dormant communities for both types of environments. Our results highlight the need to conserve both temporary and perennial environments to assure the maintenance of zooplankton diversity. Although these environments are subject to the same set of climatic variables and pool of species, their idiosyncrasies are important forces promoting and sustaining biological diversity. [ABSTRACT FROM AUTHOR]

Runcinida is a small heterobranch order of sea slugs with 61 known species distributed worldwide across temperate and tropical latitudes with two established families (Ilbiidae and Runcinidae). Little is known about the phylogenetic relationships within Runcinida. Here, we present the first molecular phylogeny of the order with an emphasis on European species and we discuss the taxonomic status of the type species Runcina coronata. Molecular phylogenetics based on the mitochondrial genes cytochrome c oxidase subunit I and 16S rRNA and nuclear gene histone H3 is used to investigate relationships between species. Detailed morpho-anatomical worked was additionally employed to study Runcina coronata. Our results suggest the monophyly of Runcinida and showed that Runcina coronata is a complex of four species, namely: R. coronata proper, R. aurata and two new species here formally described (R. caletensis sp. nov. and R. tingensis sp. nov.). [ABSTRACT FROM AUTHOR]

Background and Aims It is commonly accepted that the leaf of a crassulacean acid metabolism (CAM) plant is thick, with large mesophyll cells and vacuoles that can accommodate the malic acid produced during the night. The link between mesophyll characteristics and CAM mode, whether obligate or C3/CAM, was evaluated. Methods Published values of the carbon isotopic ratio (δ 13C) as an indicator of CAM, leaf thickness, leaf micrographs and other evidence of CAM operation were used to correlate cell density, cell area, the proportion of intercellular space in the mesophyll (IAS) and the length of cell wall facing the intercellular air spaces (Lmes/A) with CAM mode. Key Results Based on 81 species and relatively unrelated families (15) belonging to nine orders, neither leaf thickness nor mesophyll traits helped explain the degree of CAM expression. A strong correlation was found between leaf thickness and δ 13C in some species of Crassulaceae and between leaf thickness and nocturnal acid accumulation in a few obligate CAM species of Bromeliaceae but, when all 81 species were pooled together, no significant changes with δ 13C were observed in cell density, cell area, IAS or Lmes/A. Conclusions An influence of phylogeny on leaf anatomy was evidenced in a few cases but this precluded generalization for widely separate taxa containing CAM species. The possible relationships between leaf anatomy and CAM mode should be interpreted cautiously. [ABSTRACT FROM AUTHOR]

Aims Grazing exerts profound effects on grassland ecosystem service and functions by regulating species composition and diversity, and structuring community assembly worldwide. However, adaptions of phylogenetic diversity and phylogenetic community structure to long-term grazing disturbance remain poorly studied, especially for ecosystems distributed in extreme environments. Methods Here, we conducted an experiment with multigrazing intensities to explore the impacts of grazing disturbance on plant phylogenetic diversity and community structure in an alpine grassland of the Tibetan Plateau. Important Findings Grazing disturbance enriched plant species richness (SR), and stimulated species turnover from regional species pool, consequently changing community species composition. Under low intensities, grazing exerted no obvious effects on phylogenetic diversity and community structure, whereas communities changed from overdispersion to clustering under high grazing intensity. High grazing intensity resulted in stronger environmental filtering, which consequently selected those species with high resilience to grazing disturbance. The observed clustering structure was associated with the colonizing species which were closely related to resident species, and locally extinct species, and distantly related to residents. At the plant functional trait level, high grazing intensity increased species colonization largely by altering the effect of root depth on species colonization compared to light grazing. Our results highlight that solely utilization of SR and diversity cannot fully represent grassland communities responses to grazing. The effects of species turnover on community phylogenetic diversity and structure are entailed to be explored in the future grazing studies. [ABSTRACT FROM AUTHOR]

Ongoing climate change is expected to cause an increase in temperature and a reduction of precipitation levels in the Mediterranean region, which might cause changes in many species distributions. These effects negatively influence species gene pools, decreasing genetic variability and adaptive potential. Here, we use mitochondrial DNA and RADseq to analyse population genetic structure and genetic diversity of the bumblebee species Bombus terrestris (subspecies Bombus terrestris lusitanicus), in the Iberian Peninsula. Although this subspecies shows a panmictic pattern of population structure across Iberia and beyond, we found differentiation between subspecies B. t. lusitanicus and B. t. africanus , probably caused by the existence of barriers to gene flow between Iberia and North Africa. Furthermore, the results revealed that the Iberian Peninsula harbours a large fraction of B. terrestris intraspecific genetic variation, with the highest number of mitochondrial haplotypes found when compared with any other region in Europe studied so far, suggesting a potential role for the Iberian Peninsula as a glacial refugium. Our findings strengthen the idea that Iberia is a very important source of diversity for the global genetic pool of this species, because rare alleles might play a role in population resilience against human- or climate-mediated changes. [ABSTRACT FROM AUTHOR]

Unisexual vertebrates (i.e., those produced through clonal or hemiclonal reproduction) are typically incapable of purging deleterious mutations, and, as a result, are considered short‐lived in evolutionary terms. In hemiclonal reproduction (hybridogenesis), one parental genome is eliminated during oogenesis, producing haploid eggs containing the genome of a single parent. Hemiclonal hybrids are usually produced by backcrossing hemiclonal hybrids with males of the paternal species. When hemiclonal hybrids from a genus of greenlings (Hexagrammos) are crossed with males of the maternal species, the progeny are phenotypically similar to the maternal species and produce recombinant gametes by regular meiosis. The present study was conducted to determine if the hemiclonal genome is returned to the gene pool of the maternal species in the wild. Using a specific cytogenetic marker to discriminate between such progeny and the maternal species, we observed that Hexagrammos hybrids mated with maternal and paternal ancestors at the same frequency. This two‐way backcrossing in which clonal genomes are returned to the gene pool where they can undergo recombination plays an important role in increasing the genetic variability of the hemiclonal genome and reducing the extinction risk. In this way, hybrid lineages may have survived longer than predicted through occasional recombinant generation. [ABSTRACT FROM AUTHOR]

Island biogeography theory (IBT) explains and estimates large-scale ecological patterns among islands and isolated habitat patches. Specifically, IBT predicts that the number of species per habitat patch differs as a function of area and isolation as a result of local colonization and extinction. Accurate estimates of species richness are essential for testing predictions of IBT, but differences in detectability of species can lead to bias in empirical data. Hierarchical community models correct for imperfect detection by leveraging information from across the community to estimate species-specific occupancy and detection probabilities. Using the fragmented Ozark glades as our model system, we constructed a hierarchical community model to 1) estimate site-level and regional species richness of small mammals while correcting for detection error, and 2) determine environmental covariates driving occupancy. We sampled 16 glades in southwestern Missouri in summer 2016–2017 and quantified mammal community structure within the glade network. The detected species pool included eight species, and the model yielded a regional species estimate of 8.6 species, with a mean of 3.47 species per glade. Species richness increased with patch area but not isolation, and effects of patch shape varied between species in the community. [ABSTRACT FROM AUTHOR]

Background and Aims Herbivory by large mammals imposes a critical recruitment bottleneck on plants in many systems. Spines defend plants against large herbivores, and how early they emerge in saplings may be one of the strongest predictors of sapling survival in herbivore-rich environments. Yet little effort has been directed at understanding the variability in spine emergence across saplings. Methods We present a multispecies study examining whether and how sapling size, spine type and species' environmental niche (light and precipitation environment) influence early emergence and biomass investment in spines. A phylogenetically diverse pool of 45 species possessing different spine types (spines, prickles and thorns; that are derived from distinct plant organs: leaf, epidermis or cortex, and branch, respectively), were grown under common-garden conditions, and patterns of spine emergence and biomass allocation to spines at 5 and 15 weeks after transplanting were characterized. Key Results Spine type and species' resource niche were the main factors driving early emergence and investment patterns. Spines emerged earliest in leaf spine-bearing species, and latest in thorn-bearing species. The probability of early spine emergence increased with decreasing precipitation, and was greater in species from open than from closed habitats. Sapling investment in spines changed with plant mass but was contingent on spine type and habitat type. Conclusions Different spine types have strikingly different timing of expression, suggesting that developmental origins of spines play a critical role in sapling defences. Furthermore, species from different precipitation and light environments (open vs. closed habitats) showed contrasting patterns of early spine expression, suggesting that resource limitation in their native range may have driven divergent evolution of early defence expression. [ABSTRACT FROM AUTHOR]

Ostracods in Icelandic freshwaters have seldom been researched, with the most comprehensive record from the 1930s. There is a need to update our knowledge of the distribution of ostracods in Iceland as they are an important link in these ecosystems as well as good candidates for biomonitoring. We analysed 25,005 ostracods from 44 lakes, 14 springs, and 10 cave pools. A total of 16 taxa were found, of which seven are new to Iceland. Candona candida (Müller, 1776) is the most widespread species, whereas Cytherissa lacustris (Sars, 1863) and Cypria ophtalmica (Jurine, 1820) are the most abundant, showing great numbers in lakes. Potamocypris fulva (Brady, 1868) is the dominant species in springs. While the fauna of lakes and springs are relatively distinct from each other, cave pools host species that are common in both lakes and springs. Icelandic non-marine ostracods include mostly generalist species, as well as species adapted to cold climates and resemble those of other north European countries while sharing very few species with the North American Arctic. Iceland is experiencing impacts from climate change and a booming tourism. It is possible to use selected freshwater ostracods as biomonitoring tools by constructing a detailed database of these species. [ABSTRACT FROM AUTHOR]

Aims For plants to establish in a local community from a pool of possible colonizers from the region, it must pass through a series of filters. Which of the filters is most important in this process has been much debated. In this study, we explored how species are filtered from the regional species pool into local communities. The aim was to determine if differences in species abundance and functional traits could explain which species from the regional species pool establish at the local scale and if the filtering differed between grassland communities. Methods This study took place in a cultivated landscape in southeastern Sweden. We estimated plant species abundance in 12 ex-arable field sites and 8 adjacent seminatural grassland sites and in a 100-m radius around the center of each site. We used Monte Carlo simulations to examine if species abundance and functional traits (height, seed mass, clonal abilities, specific leaf area and dispersal method) controlled the filtering of species from the regional pool into local communities. Important Findings On average, only 28% of species found in the regional pool established in the ex-arable field sites and 45% in the seminatural grassland sites, indicating that the size of the regional species pool was not limiting local richness. For both grassland types, species abundance in the regional pool was positively correlated with species occurrence at the local scale. We found evidence for both species interaction filtering and dispersal limitation influencing the local assembly. Both local and regional processes were thus influencing the filtering of species from the regional species pool into local communities. In addition, the age of the communities influenced species filtering, indicating that community assembly and the importance of different filters in that process change over succession. [ABSTRACT FROM AUTHOR]

On any spatial scale, the species composition of a taxonomic group often departs from a phylogenetically random subset drawn from the pool of species available on a higher scale. Analysis of the uneven representation of related lineages in different assemblages can reveal the action of various forces shaping their diversification. For any assemblage, unequal diversification among lineages can be estimated using diversity skewness, an index of the balance of a phylogenetic tree whose values increase with increasing differences in diversification rates among tree branches. We tested for geographical patterns in the diversity skewness of flea assemblages parasitic on small mammals in 26 distinct geographic localities from the Palaearctic and 15 from the Nearctic. Overall, diversity skewness of the Nearctic flea assemblage was unexpectedly high compared to that of the global flea fauna, whereas that of the Palaearctic did not depart from the expectations of a null model. On a smaller scale, the diversity skewness of local flea assemblages was sometimes lower, sometimes higher, but, in most of the 41 localities, it did not differ significantly from that of random subsets taken from the species pool available on the larger spatial scale (either the world fauna or that of the biogeographical realm, i.e. Palaearctic or Nearctic). More importantly, among Palaearctic assemblages, diversity skewness increased with increasing latitude and/or decreasing mean air temperatures. The different patterns observed in the Palaearctic and Nearctic may be in part due the fact that flea diversification appears to have been more intense in the former than the latter, and to differences between them in relief and glacial history. Temperature-driven speciation rates may well explain the latitudinal gradient in diversity skewness in the Palaearctic. The results illustrate the action of various biogeographical processes in shaping the uneven differentiation of flea lineages on different spatial scales. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95, 807–814. [ABSTRACT FROM AUTHOR]

In many community assemblages, the abundance of organisms is a power-law function of organism size. In phytoplankton communities, changes in size structure associated with increases in resource availability and total biomass have often been interpreted as a release from grazer control. A metapopulation-like approach is used to scale up from the individual physiological responses to environmental conditions to community size structure assuming the community taxonomic composition reflects the species pool. We show that the size scaling of cellular nutrient requirements and growth can cause (1) the power-law relationship between cell size and abundance, (2) dominance of small phytoplankton cells under oligotrophic conditions, and (3) relative increase in abundance of larger phytoplankton cells under eutrophic conditions. If physiological differences associated with the taxonomic composition of different community size fractions are considered, then the model can replicate detailed field observations such as the absence of small, slow-growing Prochlorococcus spp. and the relative dominance of large diatom species in nutrient-rich, upwelling regions of the ocean. [ABSTRACT FROM AUTHOR]

Because fisheries operate within a complex array of species interactions, scientists increasingly recommend multispecies approaches to fisheries management. We created a food web model for the Baltic Sea proper, using the Ecopath with Ecosim software, to evaluate interactions between fisheries and the food web from 1974 to 2000. The model was based largely on values generated by multispecies virtual population analysis (MSVPA). Ecosim outputs closely reproduced MSVPA biomass estimates and catch data for sprat (Sprattus sprattus), herring (Clupea harengus), and cod (Gadus morhua), but only after making adjustments to cod recruitment, to vulnerability to predation of specific species, and to foraging times. Among the necessary adjustments were divergent trophic relationships between cod and clupeids: cod exhibited top-down control on sprat biomass, but had little influence on herring. Fishing, the chief source of mortality for cod and herring, and cod reproduction, as driven by oceanographic conditions as well as unexplained variability, were also key structuring forces. The model generated many hypotheses about relationships between key biota in the Baltic Sea food web and may ultimately provide a basis for estimating community responses to management actions. [Copyright &y& Elsevier]

Examines criteria for determining species richness in setting conservation priorities. Widespread destruction of habitats for nearly all species; Difficulty in prioritizing what species to save; Lack of range data for many species; Search for indicator taxa; Ecoregion map and species distributions; Correlations in species richness among taxa; Potentially problematic patterns; Biases in species richness data; Applicability of data to other regions.

Land-use and soil characteristics drive variation in soil community composition, but the influences of these factors on dispersal and community assembly at regional scale remain poorly characterized. Land-use remains a consistent driver of soil community composition even when exhibiting patchy spatial distribution at regional scale. In addition, disturbed and early successional soils often exhibit stochastic community assembly patterns. These observations suggest local community composition is influenced by dispersal and assembly from regional species pools. We examined bacterial community assembly within agricultural cropland, old-field, and forested sites across 10 landscapes in the region around Ithaca, New York (USA). We found that the Sloan neutral model explained assembly well at regional scale (R2 = 0.763), but that both soil pH and land-use imposed selection that shaped community composition. We show that homogeneous selection was a dominant assembly process with respect to both soil pH and land-use regime, but that these two factors interacted in their effects on bacterial community assembly. We conclude that bacterial community assembly at a regional scale is driven by dispersal from regional species pools and local selection on the basis of soil pH and other soil characteristics that vary with land-use. [ABSTRACT FROM AUTHOR]

The article reports on a study concerning recognition of sibling species of horseflies. researcher proposed that the salt marsh greenhead, Tabanus nigrovittatus, actually consists of sibling species of horse flies. He collected Tabanus larvae which appeared morphologically and ecologically distinct from T. nigrovittatus and designated them Tabanus species 3. It is reported that electrophoresis of proteins often helps to differentiate between closely related species for which good morphological characters are not apparent. Researchers informed how they made use of genetic basis as a parameter to differentiate between closely related species.