Differences In Species Composition Research Articles

Does habitat type in no‐tillage agroecosystems influence ground‐dwelling macroarthropod community structure? A case study in KwaZulu‐Natal, South Africa

AbstractLoss of biodiversity in agroecosystems has negative implications for crop production and the functioning of the ecosystem. As such, agroecologists advocate minimum tillage practices in order to conserve biological diversity. To establish the influence of agricultural practices on biodiversity, we compared the species richness, abundance and composition of beetles, ants, spiders and small groups of ground dwelling arthropods in a veld and three agroecosystems (maize, sugarcane and multispecies pasture) under minimum tillage. Sampling was by pitfall trapping during the summer rainfall season in December 2019. Although ants were the most abundant (47%), followed by beetles (31%); beetles were the most speciose making up 40% of the morphospecies followed by spiders (31%). The veld had significantly greater relative proportion of species richness of spiders (54%) than the three agroecosystems, while significantly low relative proportion of species richness of ants was in the pasture (6%) compared to the veld (63%). Species richness and abundance of beetles were similar across habitat types. The four habitats supported different assemblages of ants, beetles and spiders. The differences in species composition among the habitats support the notion that agricultural practices with minimum soil disturbance enhance conservation of biological diversity, particularly, specialist species.

Agroforestry orchards support greater butterfly diversity than monoculture plantations in the tropics

Large-scale deforestation in the tropics, triggered by logging and subsequent agricultural monoculture has a significant adverse impact on biodiversity due to habitat degradation. Here, we measured the diversity of butterfly species in three agricultural landscapes, agroforestry orchards, oil palm, and rubber tree plantations. Butterfly species were counted at 127 sampling points over the course of a year using the point count method. We found that agroforestry orchards supported a greater number of butterfly species (74 species) compared to rubber tree (61 species) and oil palm plantations (54 species) which were dominated by generalist (73%) followed by forest specialists (27%). We found no significant difference of butterfly species composition between agroforestry orchards and rubber tree plantation, with both habitats associated with more butterfly species compared to oil palm plantations. This indicates butterflies were able to persist better in certain agricultural landscapes. GLMMs suggested that tree height, undergrowth coverage and height, and elevation determined butterfly diversity. Butterfly species richness was also influenced by season and landscape-level variables such as proximity to forest, mean NDVI, and habitat. Understanding the factors that contributed to butterfly species richness in an agroecosystem, stakeholders should consider management practices to improve biodiversity conservation such as ground vegetation management and retaining adjacent forest areas to enhance butterfly species richness. Furthermore, our findings suggest that agroforestry system should be considered to enhance biodiversity in agricultural landscapes.

Responses of Urban Bird Assemblages to Land-Sparing and Land-Sharing Development Styles in Two Argentinian Cities

Urbanization negatively affects biodiversity worldwide. Consequently, alternative urban development styles are required for an eco-friendlier urbanization process. Thus, two development styles have been suggested: land-sharing (buildings mixed with dispersed green space) and land-sparing (buildings interspersed with large green patches). We assessed differences in species diversity and composition of bird assemblages between both development styles in two Argentinian cities: Santa Fe and Buenos Aires. We surveyed birds in land-sharing and land-sparing areas during the breeding and non-breeding seasons. As a control, we also surveyed birds in areas dominated by impervious surfaces. At a local scale, we also measured the environmental noise and pedestrian traffic. At a landscape scale, we measured the percent vegetation cover surrounding development styles and their distance to the main river. In Buenos Aires, species richness was higher in land-sparing than in land-sharing. However, the Shannon diversity and Simpson diversity were higher in land-sharing. In Santa Fe, both urban development styles supported similar species richness and diversity. Species composition varied between land-sharing and land-sparing in both cities during the breeding season. The pedestrian traffic was negatively associated with species diversity. Therefore, both development styles and strategies to reduce pedestrian traffic should be taken into account to enhance different components of species diversity and composition within the urban matrix.

Plant diversity in traditional agroecosystems of North Morocco

Questions: While globalisation favours intensive yield-maximizing agriculture with cropping practices that entail agrobiodiversity loss, extensive production systems still exist in areas of marginal lands such as in mountainous regions or islands. It is overdue to study such systems, their sustainability and ecology as potential models for decentralized environmentally balanced land-use. For that purpose, we investigated the composition of the wild arable (segetal) flora in traditional thermo- to mesomediterranean cereal-growing agroecosystems of northwestern Morocco. Study area: The Tingitane (Tangier) Peninsula in the Northwest of Morocco. Methods: A sample of 94 relevés was collected in six areas in the foreland of the Rif Mountains. Results: We found 209 species in 150 genera and 41 families, a mean of 22 species per relevé and a Shannon index of 3.04±0.06. A TWINSPAN classification revealed a high level of similarity between the areas, with the plant communities corresponding to the order Brometalia rubenti-tectorum, but also differences in species composition as a result of climatic, soil and land-use effects. Therophytes dominated, but biennial and perennial herbs indicating shallow tillage and fields under fallow were also common. Almost half of the species found were agrestal species (confined to arable fields), and almost a third were apophytes (native species occurring in fields but also in natural habitats). Twenty-nine species (14%) of the segetal flora were regional endemics and six are considered nationally rare. Although there is evidence of recent structural and floristic diversity decline, traditional agroecosystems tend to favour native species including some of particular conservation interest. Conclusions: The traditional agroecosystems of the Rif Mountains fulfil criteria of High Nature Value agriculture but, in view of recent socio-economic change, require support by policy for their maintenance. Taxonomic reference: Euro+Med PlantBase (http://www.europlusmed.org) [accessed 26 Nov 2022]. Syntaxonomic reference: EuroVegChecklist (Mucina et al. 2016). Abbreviations: TWINSPAN = Two Way Indicator Species Analysis.

Retained fish catches of artisanal fishers is dependent on fishing area, season and fishing gear type: A case study from the south coast of Kenya

The artisanal fishery is one of the sources of livelihood along the Kenya coast. Catches of retained fish of artisanal fishers between two fishing areas on the south coast of Kenya were compared. Artisanal fishers usually retain a portion of their daily catch which is reserved for family consumption while the rest is traded for cash to meet other family needs. This study hypothesized that retained fish catches were influenced by fishing area, fishing gear type and season. Daily fish landings and retained fish catches among artisanal fishers were monitored between August 2020 to July 2021 covering the South East Monsoon (SEM) and North East Monsoon (NEM) in Msambweni and Vanga fishing areas. A total of 60 fishers (30 for each area) were randomly selected and their retained catch monitored on a daily basis. The overall total fish landings were 23.3 tons and 210 tons in Msambweni and Vanga, respectively. The mean catch rate at Msambweni was 3.3 ± 0.12 kg.fisher-1day-1 in the NEM season and 2.2 ± 0.09 kg.fisher-1day-1 in the SEM season. Fish catch rates in Vanga was 8.5 ± 0.28 kg.fisher-1day-1 in the NEM season and 7.9 ± 0.29 kg.fisher-1day-1 in the SEM season. A total of 0.98 tons (only 4.2 %) of fish was retained versus 22.32 tons (95.8 %) not retained by the artisanal fishers in Msambweni, while in Vanga a total of 1.64 tons (only 0.78 %) was retained versus 208.36 tons (99.22 %) not retained. Retained fish catch varied significantly with season and type of fishing gear used (p < 0.05). Among the retained species in Msambweni, Siganus sutor made the highest contribution (53 %), followed by Lethrinus mahsena, (5.08 %). The species Euthynnus affinis and Sphyraena obtusata were mostly retained in Vanga with a contribution of 10.4 % and 10.2 %, respectively. The same retained fish species represented the most abundant species in the overall fish landings, however sizes were significantly smaller than those not retained by fishers (p < 0.05). Results of non-Metric Multidimensional Scaling (nMDS) ordination showed differences in species composition between fishing areas, seasons and fishing gear types with implication on fishers’ retained catches.

Space-time patterns and drivers of migrant bird communities in coastal Piauí State, Brazil

Introduction: Migration is a natural phenomenon that includes annual movements of many bird species in response to seasonal cycles. With approximately one third of all living bird species, South America has an important avifauna, and many migrants land in Brazil at stopping points and wintering sites. Objective: To identify associations between migrant birds and coastal vegetation, and environmental influence of on migration. Methods: At 10 points along the coast of Piauí State, Brazil, we made visual censuses and mist net captures, between April 2009 and February 2016. Results: We identified 82 migrant bird species (13 orders; 28 families) that represented 41 intracontinental migrating species, 26 northern visiting species, 14 nomad species and one vagrant species. The richness peaks were at the beginning and end of both dry and rainy seasons, matching insolation and atmospheric pressure. There were spatial pattern differences among vegetation complexes. Chrysolampis mosquitus is an indicator of caatinga vegetation, Numenius phaeopus of wetland, Charadrius collaris of non-flooding fields, Rostrhamus sociabilis of forest-grassland transition, and Columbina picui of orchards. Despite differences in number and species composition within vegetation types, the temporal pattern in species richness was similar among flooded fields, non-flooded fields, and transition grassland categories. Conclusions: Migrant birds occupy specific environments during their permanence along the coast of Piauí State, with richness matching insolation and atmospheric pressure.

Community structure of benthic molluscs shaped by environmental and ecological variables in the coastal waters of Changle, Fujian Province, China

To understand the community structure of benthic molluscs and their relationship under varying environmental and ecological conditions, monthly samplings in April−September 2019 were conducted at 27 stations in an approximate sea area of 20,600 ha (Changle District, Fujian Province, China). Forty-five species were identified, most as food; six dominant species, all bivalves and commercially important, were determined by the index of relative importance > 500. The average abundance and biomass were 308.32 × 103 ± 1,156.24 × 103 ind./km2 and 1,423.71 ± 2,272.37 kg/km2, respectively. Three spatial community groups were identified, named Min River Estuary, Nearshore, and Offshore, with significant differences in species composition and abundance (ANOSIM, p < 0.01). Results of the canonical correlation analysis indicated that the community structure of benthic molluscs was significantly related to water depth, pH, salinity, temperature, phytoplankton abundance and zooplankton abundance (p < 0.1). As the important habitat for benthic molluscs, long-term monitoring in the coastal waters of Changle is needed for sustainable harvest.

Amphibian communities along a forest degradation gradient in an East African forest reserve

The amphibian communities in Africa's tropical forests are of global conservation importance, but disturbances derived from anthropological activities threaten to dismantle this irreplaceable diversity. We explored the impacts of forest degradation on the amphibian community in Mabira Central Forest Reserve, Uganda. We sampled amphibians from March to July of 2015 in plots that were positioned along a gradient of forest degradation. We conducted visual encounter surveys across three categories of forest degradation with six 300-m transects in each (four surveys per transect). From 216 h of surveyor effort, we detected 3563 individual frogs representing 30 species from eight families and 13 genera. Hyperoliidae was the most diverse family represented by 13 species in four genera. Hyperolius had the highest number of species (nine) followed by four genera each represented by three species (Phrynobatrachus, Pytchadena, Leptopelis, and Sclerophrys). Comparisons among plots along a gradient of forest degradation revealed differences in species richness, composition, and frequency of encounters. The regenerating and degraded forest plots were similar in species composition to each other and were dominated by mostly widespread, open-canopy species. Several forest-dependent species were recorded in both the regenerating and mature forest plots but were absent from the degraded plots. In the regenerating and mature forests, species presence was significantly associated with high canopy cover, high relative humidity, and dense leaf litter, whereas the microhabitat variables of high grass cover and high temperature were most influential in the degraded forests. Our study provides important data on an Afrotropical amphibian community and suggests that forest degradation has dramatically altered the habitat to the detriment of forest specialist species.

Ecological drivers of dissimilarity in multidimensional plant composition of early‐stage plantations in a loess hilly‐gully region

AbstractPlant diversity is an important link between forest ecosystems' structural composition and functional processes. The simple composition of young plantations is weakening the ecological function of restored forest ecosystems in arid regions. The ecological drivers of the plant composition and dissimilarity in plantations remain unclear, especially in the early restoration stage. To fill the gap in knowledge of the differences in species composition in early restored ecosystems, and to reveal the influencing factors of similar species numbers with different compositional structures, based on species' presence‐absence, abundance, and conspicuousness, we explored dissimilarity in the plant composition of young plantations in the loess hilly‐gully region. Our results showed that differences in alpha diversity among plantations were minimal, while the differences in beta diversity were significant. Even if the species diversity of a plantation was low, communities with similar species richness used to have large dissimilarities in their species composition. Turnover components and balanced variation often contributed significantly to species compositional dissimilarity. Co‐inertia analysis results showed species conspicuousness had the greatest consistency with observed environmental variables (RV = 0.65). The redundancy analysis and generalized diversity modeling results showed differences between the drivers of species diversity and dissimilarity. The primary influencing factors for alpha diversity were: soil water content, soil texture, soil total phosphorus, and soil organic carbon. Primary influencing factors for dissimilarity (beta diversity) were: soil nitrogen to phosphorus ratio, breast‐height diameter, soil water content, and stand density. Collectively, plant taxa dissimilarity was influenced by soil nutrient ratio and community structure and plant taxa abundance was influenced by soil nutrient content. Our findings improve the understanding of the plantation species composition and facilitate the prediction of ecological functions.

Initial herbivory and exposure to herbivory-induced volatiles enhance arthropod species richness by diversifying community assemblages

Plant ecological traits affect the species identity of plant-colonizing arthropods, which in turn induces species-specific trait changes in plants, forming feedback between plants and arthropods. Such feedback can amplify initial differences in species composition, leading to large variations (i.e., high β diversity). We hypothesized that the differences in plant initial conditions have sustained effects on arthropod community composition and species richness. To test this hypothesis, we monitored arthropod community assembly on a willow tree species, Salix eriocarpa, which was experimentally manipulated into three initial treatments: undamaged (in chamber 1); damaged by the specialist leaf beetle, Plagiodera versicolora (chamber 2); and “exposed” plants that were undamaged but were exposed to volatiles from damaged plants (in chamber 2). The arrival and population dynamics of the leaf beetle were affected by the plant’s initial condition (chamber 1 vs. 2), which could result from the microscale environmental heterogeneity between chambers (chamber effect) and/or from the herbivory-related impacts (direct herbivory and exposure to induced volatiles in chamber 2). The community composition on damaged and exposed plants became significantly different on day 32. In addition, the divergence in composition between plant individuals was significantly smaller in undamaged plants (chamber 1) than in damaged and exposed plants (chamber 2) on day 60. The compositional variations (β diversity) between chambers, between treatments, and between days, comprised a large proportion (two third) of the total species richness (γ diversity) in the whole community of arthropods. These results suggest that plant initial condition is a key driver of community assembly and the maintenance of species diversity.

Successional Change and Fire History in Montane Longleaf Pine-Dominated Ecosystems of Northwestern Georgia, USA

In the absence of fire, Pinus palustris (Longleaf Pine) ecosystems in the southeastern United States are vulnerable to successional change including mesophication, a process where increases in the importance of mesic and fire-intolerant species reduce biodiversity and thwart efforts to restore these systems. To determine the degree and nature of this successional trajectory at a local scale, we examined changes in species composition of a montane Longleaf Pine ecosystem in northwest Georgia using modern vegetation surveys and historical “witness tree” data. We also determined historical fire frequency using fire scars within Longleaf Pine stumps cross-dated to extant Longleaf Pine trees. Modern forest composition contained significantly more fire-intolerant taxa than the historical forest due to increased abundance of mesophytic species, especially Acer rubrum (Red Maple) and decline of Pinus spp. (pines) and some pyrophytic Quercus spp. (oaks). Counter to expectation, there were few differences in species composition between northeastern- and southwestern-facing slopes in modern or historical data. Fire scars indicated a historical mean fire-return interval of 5.5 years and suggest that without the reintroduction of more frequent prescribed fire, regeneration of montane Longleaf Pine is unlikely. Additional restorative techniques may also help these stands support greater biodiversity over time. For instance, co-dominance of pines and oaks in the historical forest suggests that fire-tolerant oaks should be retained in montane restoration efforts.

Changes in taxonomic and functional diversity of an urban stream fish assemblage: A 30-year perspective

Globally, freshwater fish diversity is rapidly changing in response to land use change, including urbanization. Time series of freshwater fish communities can help elucidate the underlying mechanisms of species loss and gains, as well as promote conservation strategies. Traditional approaches to understand the dynamics of fish assemblages is traditionally focused on taxonomic diversity, one aspect among many dimensions of biodiversity. Thus, using complementary analytical methods, such as functional diversity, can help researchers to develop a stronger predictive framework on the effects of the species loss or gains in response to urbanization. We assessed temporal changes of fish assemblages in an urban stream in East Texas between four seasonal surveys of 1989–1990 and 2018–2019. We explored the similarities and differences in species richness, composition, and functional diversity of fishes. Although the species richness and functional richness between the two time periods were similar, we observed changes in species composition. We also observed higher functional dispersion and evenness in the 2018–2019 assemblage compared to 1989–1990 assemblage. Some fish species were locally extirpated, while others colonized the system, increasing the functional diversity of the current assemblage. Urbanization has commonly been associated with declines in diversity and richness, however, our findings suggest that the addition of a few invasive generalist species (e.g., blue tilapia) and native tolerant (e.g., redbreast sunfish, blacktail shiner) in this stream system could be associated with increased human activities in this small, urbanized area in East Texas. Streams in East Texas support very diverse fish assemblages, with some sentinel species (e.g., imperiled shiners: Sabine shiner, a habitat-affinity, broadcast spawner) rapidly responding to stream alterations. Multiple stressors can underlie the dynamics and composition of fish assemblages; thus, it is essential for more comparative studies of current and historical data of fish assemblages. Likewise, studies targeting sentinel fish species may have more utility for the evaluation of freshwater ecosystems.

Effects of land use change on the functional diversity and composition of mixed species avian flocks in the high tropical Andes of southern Ecuador

One of the greatest threats to biodiversity is land use change. Habitat alteration can have strong impacts on functional diversity, i.e., the range of biological traits within a suite of organisms. Mixed species avian flocks are integral to maintaining both taxonomic and functional diversity in tropical forests as they provide participants with greater foraging efficiency, reduced predation risks, and increased resiliency of species and ecosystems to environmental change. Our aim for this study was to determine the effects of land use change on the taxonomic and functional structures of mixed species avian flocks in and around Cajas National Park, Azuay Province in the tropical Andes of southern Ecuador by comparing non-native vegetation in agricultural plots and forest regenerating from historical use as pastureland to the largest intact primary forest in the region. We found no changes in species richness and diversity or functional richness of flocks across habitats, but we did find significant differences in species composition. Surprisingly, we found higher functional diversity and uniqueness of flocks in regenerating forest with more diverse and structurally complex vegetation, but native and non-native forests were functionally similar. We did, however, find significant differences in the community weighted means of four of five functional traits in different habitat types. Overall, the taxonomic and functional structures of mixed species flocks in this region seem relatively unaffected by land use change, indicating flocking as a beneficial strategy for species with higher sensitivities to disturbance in areas with anthropogenic activities. It is critical to maintain functional diversity in ecosystems, as a greater variety of functional traits and functional redundancy implies an efficient and more resilient ecosystem in the face of environmental change. Mixed species flocks provide membership benefits that may mitigate impacts of disturbance via land use change and thus can be considered essential units for conserving avian biodiversity.

Classification of European oak–hornbeam forests and related vegetation types

AbstractAimsOak–hornbeam forests and related vegetation types (phytosociological order Carpinetalia betuli) are widespread in temperate western Eurasia. However, their national classification systems are poorly compatible, and a broad‐scale classification based on numerical analyses is lacking. Therefore, we aimed to establish a unified formalized classification system based on a large data set of vegetation plots covering the entire range of these forests.LocationEurope, Anatolia, Caucasus and northern Iran.MethodsWe compiled a data set of 15,817 vegetation plots from the European Vegetation Archive and the Hyrcanian Forest Vegetation Database, using the formal definition of the EUNIS habitat type T1E Carpinus and Quercus mesic deciduous forest. We classified the data set using TWINSPAN. Biogeographically and ecologically similar plot clusters were merged into oak–hornbeam forest types, which were interpreted as alliances. We also developed expert systems for automatically classifying vegetation at the alliance level for both the EuroVegChecklist (EVC) system and the revised classification. In addition, we calculated ordinations to show the major gradients in the species composition of the data set.ResultsWe present a revised classification system of the order Carpinetalia betuli with nine alliances, including basic descriptions of their species composition, distribution, ecology and syntaxonomy. The analyses largely supported the biogeographic concept of classification, analogous to EVC. Compared to EVC, we recognized an additional alliance Physospermo verticillati‐Quercion cerridis (southern Italy) but found no support for the alliances Astrantio‐Carpinion, Erythronio‐Carpinion and Scillo‐Quercion. The greatest difference in species composition was found between the southern and northern‐northeastern Carpinetalia types. Expert systems for the revised classification system (~89% of plots classified) and the EVC system (~72%) are also included.ConclusionsWe provide the first comprehensive overview of alliances of the order Carpinetalia betuli across its whole distribution range. The associated expert systems allow consistent application of the classification of these forests in nature conservation, habitat monitoring, and biodiversity and ecological research.

Sarcopenia and gut microbiota alterations in patients with hematological diseases before and after hematopoietic stem cell transplantation.

The aim of this study was to investigate the prevalence of sarcopenia (SP) and its relationship with gut microbiota alterations in patients with hematological diseases before and after hematopoietic stem cell transplantation (HSCT). A total of 108 patients with various hematological disorders were selected from Peking University People's Hospital. SP was screened and diagnosed based on the 2019 Asian Sarcopenia Diagnosis Strategy. Physical measurements and fecal samples were collected, and 16S rRNA gene sequencing was conducted. Alpha and beta diversity analyses were performed to evaluate gut microbiota composition and diversity. After HSCT, significant decreases in calf circumference and body mass index (BMI) were observed, accompanied by a decline in physical function. Gut microbiota analyses revealed significant differences in the relative abundance of Enterococcus, Bacteroides, Blautia and Dorea species before and after HSCT (P<0.05). Before HSCT, sarcopenic patients had lower Dorea levels and higher Phascolarctobacterium levels than non-sarcopenia patients (P<0.01). After HSCT, no significant differences in species abundance were observed. Alpha diversity analysis showed significant differences in species diversity among the groups, with the highest diversity in the post-HSCT 90-day group and the lowest in the post-HSCT 30-day group. Beta diversity analysis revealed significant differences in species composition between pre- and post-HSCT time points but not between SP groups. Linear discriminant analysis effect size (LEfSe) identified Alistipes, Rikenellaceae, Alistipes putredinis, Prevotellaceae defectiva and Blautia coccoides as biomarkers for the pre-HSCT sarcopenia group. Functional predictions showed significant differences in anaerobic, biofilm-forming and oxidative stress-tolerant functions among the groups (P<0.05). This study demonstrated a significant decline in physical function after HSCT and identified potential gut microbiota biomarkers and functional alterations associated with SP in patients with hematological disorders. Further research is needed to explore the underlying mechanisms and potential therapeutic targets.

Herpetofauna das áreas protegidas da Caatinga VIII: Um inventário atualizado para a região da Serra das Confusões com novos dados da Serra Vermelha, Piauí, Brazil

Abstract It is repeatedly stressed the need to characterize the extant biodiversity in tropical ecosystems. However, inventory studies are still progressing slowly in dry ecosystems, leading to the underestimation of their true biodiversity and hindering conservation efforts. In this study, we present primary and secondary data, along with an updated list of amphibians and reptiles from two localities in the São Francisco-Gurguéia region in Piauí. Additionally, we compare the species composition between nine areas within the Caatinga, which were sampled using standardized methods over the past ten years, to examine broader spatial patterns of community composition. To survey reptiles and amphibians, we employed similar methods and sampling efforts in two areas within the Serra das Confusões National Park (SCNP) region. Our surveys recorded a total of 73 species of amphibians and reptiles, of which 24 are new distribution records for the SCNP region. Consequently, our findings increase the known herpetofauna in the region to 94 species. Despite their proximity, the two sites in the SCNP region exhibited only 42% similarity in species composition, and they differed significantly from other areas within the Caatinga. Furthermore, even the closer Caatinga areas presented differences in species composition, highlighting the necessity to evaluate biodiversity across the landscape and contribute to understanding biogeographic patterns.

Differences in the structure of bat assemblages among habitats in the Caatinga dry forest

Abstract The Caatinga is the largest seasonal tropical dry forest with extreme environmental and meteorological conditions. It harbours many phytophysiognomies and vegetational units, but bat fauna is poorly known in many regions. We analysed the structure of bat assemblages by mist-netting during 99 nights in seven habitats throughout six sites in the northeasternmost region of the Caatinga in Rio Grande do Norte State, in the Brazilian northeast. With a sampling effort of 239 665 m2h, we captured 1575 individuals of 31 species of bats. Bat assemblages’ structure and species distribution changed according to the habitat type, and differences in richness, abundance, species composition, and trophic guild representation were found. The frugivore A. planirostris was widespread, and its superabundance hold for all habitats. The distinct array of the most abundant species with several exclusive species in each habitat suggests species- and trophic guild-specific preferences to particular habitats. Differences in the structure of bat assemblages may be driven by each habitat’s vegetational structure and plant composition (e.g., semi-open habitats vs. tall forest stands) that offers distinct exploitable resources (e.g., food and roosts). Finally, we discuss the importance of foraging habitats for the conservation of these unique bat assemblages in the northeasternmost region of the Caatinga dry forest.

Detection of foray behaviour in zooplankton of the Antarctic Polar Front region

In addition to diel vertical migration, individual zooplankton may also make a number of shorter-term migrations, or forays, into the surface layers from deeper depths. Direct observation of these forays is limited, particularly in the open ocean, which hinders our understanding of carbon flux via the biological carbon pump (BCP). We designed a novel net device capable of trapping zooplankton during such forays. The motion-compensated upward and downward looking (MUDL) net device consisted of 2 conical nets, one looking upwards and the other looking downwards, designed for stationary deployment at a set depth, into which migrating individuals must swim to be captured. The device was deployed at different time points within the diel cycle and at contrasting environments across the Antarctic Polar Front region in the southwestern Atlantic sector of the Southern Ocean. A range of zooplankton species were captured, with differences in abundance and species composition between times of day, net directions and sites. Of particular note was the large contribution of the copepod Oithona spp. to catches of both the upward and downward looking nets. Our study demonstrates the utility of our MUDL net for future ecosystem studies in the open ocean, particularly in relation to quantifying vertical carbon flux via the BCP.

Spatio-temporal differences in pollinator species richness, abundance and conservation status in a Mediterranean island

Although the Mediterranean basin is a hotspot of pollinator diversity, little is still known about how such diversity is distributed in the region and about its conservation status. This study contributes to filling this information gap by studying pollinator diversity parameters in one of the main Mediterranean islands, Mallorca, and further evaluating their conservation category according to the IUCN criteria. We focus on three communities, two coastal and one mountain shrubland, which we have studied for several years. For each community, we obtained the following variables: (1) Shannon diversity (H'), (2) Pielou's index (J'), (3) Number of pollinators per plant (Lp), (4) Flower visitation rate (FVR), (5) Specialisation index (d') and (6) Normalised degree of pollinators, i.e. the number of plants visited per pollinator species relative to the total number of plant species in the community (ND). All pollinators were categorised into functional groups to test for differences in such variables among them. Differences across communities, years and functional groups were tested through GLMMs. The three communities showed differences in pollinator species composition, species richness and diversity. Pollinator diversity also varied with time, especially in the coastal community, which suffered a major disturbance during one of the study years. Regardless of the functional group, the pollinator specialisation degree seems context-dependent. Native and endemic species might disappear in the short term if appropriate management measures are not taken to narrow down the threats to pollinator populations. Further research is urgently needed to assess most insect pollinators' conservation status in the Mediterranean before such rich diversity is lost forever.

Plant species-specific responses and community associations with fire season

Many temperate pine forests are characterized by midstory hardwood encroachment that inhibits timber production and limits herbaceous vegetation needed by wildlife. In the southeastern United States, lack of historical fire regimes compounds this problem and may require additional treatments to control woody vegetation. Research on fire season impacts on plant community dynamics exists, but studies often disagree on the most effective fire season for hardwood control. Our study evaluated the role species composition may have in overall plant community response to dormant season (March) and growing season (June) fire and explored associations with fire temperature 2 years post-fire in thinned (x = 22 m2 ha−1) loblolly pine (Pinus taeda) stands in east-central Mississippi. Growing season fire (Growing) reduced midstory stem density (shrubs and trees ≥ 1.37 m in height and ≤ 15 cm diameter at breast height) by 47 % relative to unburned control (Control) stands which did not differ from dormant season fire (Dormant; 1.3 % reduction). Five of 22 species responded to fire season similar to the midstory as a whole, but 77 % of species deviated. We identified 7 fire season response patterns, 3 of which are exemplified by: American beautyberry (Callicarpa americana) stem densities increased 135 % following Dormant, persimmon (Diospyros virginiana) decreased 32 % after Dormant, and mockernut hickory (Carya tomentosa) was unaffected by fire season. We found no influence of fire temperature on stem densities but Growing was hotter than Dormant with average temperatures of 376 (SE = 16) and 321 (SE = 12) C, respectively. In contrast to varied response patterns by midstory species, significant effects relative to Control in the understory include a 76 % increase in forb coverage by Growing and 18 % increase in grass coverage and 34 % increase in woody coverage by Dormant. Indicator species analyses showed non-native species in the midstory and understory were associated with Control and Dormant but not Growing. These results suggest the disparity in midstory community response reported in fire timing studies is partly due to differences in species composition. Managers can use these response patterns to tailor management plans to site conditions for a variety of objectives including timber production and wildlife.