Forest Assemblages Research Articles

Biodiversity of Kelp Forests and Coralline Algae Habitats in Southwestern Greenland

All marine communities in Greenland are experiencing rapid environmental change, and to understand the effects on those structured by seaweeds, baseline records are vital. The kelp and coralline algae habitats along Greenland’s coastlines are rarely studied, and we fill this knowledge gap for the area around Nuuk, west Greenland. Using subtidal swath surveys, photo-quadrats, and grab samples, we characterised the diversity of floral and faunal assemblages in kelp forests and coralline algae beds. The most abundant herbivore assemblages and the most diverse communities occur in the interstitial habitats of rhodolith beds. In kelp forests, species diversity is higher in epi-benthic (photo-quadrat) and mid-water (swath) surveys. These habitats are not mutually exclusive; Agarum clathratum is prominent in coralline algal habitats, while crustose coralline algae cover the bedrock under kelp holdfasts. Overall, the suite of surveys used capture the diverse communities within kelp forests and coralline algae in Greenland and their differing role in the life history of the inhabitants. Furthermore, coralline algae beds are an important carbonate store, with CaCO3 concentrations ranging from 28.06 to 103.73 g·m−3. Our research sets the baseline for continued investigations and monitoring of these important habitats and their supported fisheries.

Functional Redundancy in bird community decreases with riparian forest width reduction.

Riparian ecosystems are suffering anthropogenic threats that reduce biodiversity and undermine ecosystem services. However, there is a great deal of uncertainty about the way species composition of assemblages is related to ecosystem function, especially in a landscape fragmentation context.Here, we assess the impact of habitat loss and disturbance on Functional Diversity (FD) components Functional Redundancy (FRed), Functional Evenness (FEve), and Functional Richness (FRic) of riparian forest bird assemblages to evaluate (a) how FD components respond to riparian forest width reduction and vegetation disturbance; (b) the existence of thresholds within these relationships; (c) which of the main birds diet guild (frugivores, insectivores, and omnivores) respond to such thresholds. We predict that FD components will be affected negatively and nonlinearly by riparian changes. However, guilds could have different responses due to differences of species sensitivity to fragmentation and disturbance. We expect to find thresholds in FD responses, because fragmentation and disturbance drive loss of specific FD components.Our results show that FRed and FEve were linearly affected by width and disturbance of riparian habitats, respectively. FRed was significantly lower in riparian forests assemblages below 400 m wide, and FEve was significantly higher above 60% disturbance. These responses of FD were also followed to the decline in insectivores and frugivores richness in riparian forests most affected by these changes.Consequently, our study suggests communities do not tolerate reduction in riparian forest width or disturbance intensification without negative impact on FD, and this becomes more critical for riparian area <400‐m wide or with more than 60% disturbance. This minimum riparian width required to maintain FRed is greater than the minimum width required for riparian forests by Brazilian law. Thus, it is important to consider mechanisms to expand riparian habitats and reduce the disturbance intensity in riparian forests so that riparian bird community FD may be effectively conserved.

Bat assemblages in fragmented forest complexes near Rogów (central Poland)

AbstractHabitat fragmentation affects bat assemblages living in forests by changing species composition, species richness and population densities. The aim of this paper was to determine the structure of bat assemblages in fragmented forests of central Poland (Experimental Forest Station SGGW in Rogów) based on data concerning bat fauna of this area.Our work is based on published as well as unpublished data collected between 2011–2017 and the two main methods employed during field work were: (1) evening and night bat netting, (2) detection of flying bats on transects or in points by using ultrasound detectors. 16 bat species were observed with the most common ones being serotine batEptesicus serotinus(Schreb.), common noctuleNyctalus noctula(Schreb.) and brown long-eared batPlecotus auritus(l.). less numerous in overall but frequently observed in some sites were the western barbastelleBarbastella barbastellus(Schreb.) and the Daubenton's batMyotis daubentonii(Kuhl). The following species occurred rarely: greater mouse-eared batMyotis myotis(Bork.), Natterer's batM. nattereri(Kuhl), whiskered batM. mystacinus(Kuhl), Brandt's batM. brandtii(evers.), northern batEptesicus nilssonii(Keys. &amp; Blas.) parti-coloured batVespertilio murinusl., lesser noctuleNyctalus leisleri(Kuhl), common pipistrellePipistrellus pipistrellus(Schreb.), nathusius' pipistrelleP. nathusii(Keys. &amp; Blas.), soprano pipistrelleP. pygmaeus(leach) and grey long-eared batPlecotus austriacus(Fish.).Fragmented forests of the study area did not differ significantly in terms of bat species composition from other fragmented forests of central Poland (Płońsk Plain) nor the large forest complexes of the Bolimowska and Kampinoska Forests. In this study area, however, bat assemblages were characterized by a lower relative abundance of the common noctule and a higher relative abundance of the serotine bat as compared to assemblages in other forests of central Poland.In conclusion, the forest fragmentation near Rogów does not significantly affect bat richness and fertilized habitats are suitable for relatively large populations of species such as the western barbastelle and lesser noctule.

Impacts of Inundation on Bird Assemblages in Forests in and around a Hydrodam in Terengganu, Malaysia

Despite the increasing numbers of hydrodam worldwide, only a handful of studies evaluated their impacts on biodiversity. Compared to terrestrial animals, birds were thought to be less affected by inundation process, following impoundment. At the Hulu Terengganu Hydroelectric Dam in Peninsular Malaysia, our study compared species assemblages and diversity of birds within the dam area (i.e. the dam reservoir and catchment area) after recent logging and inundation in relation to a nearby forest logged 30 years ago. Using point count and mist-netting techniques, we recorded a total of 64 species (Shannon Index (H’) = 3.827) in the dam area and 91 species (H’=3.99) in historically-logged forests. Insectivore species richness was significantly higher in the historically-logged forests (Mann-Whitney: Z=4.339, N=205, p<0.005). These results indicated that richness and diversity of bird species assemblages appear to decline following recent inundation phase. Nevertheless, the forests in the dam area still harbour charismatic species such as eagles (Family: Accipitridae) and hornbills (Family: Bucerotidae) which suggests that this habitat is relatively important for birds.

The first report of composition and occurrence of myxomycete assemblages in protected and unprotected plantation forests: a comparative study in Thai Nguyen City, Northern Vietnam

Background and aims – In spite of the cosmopolitan distributions of myxomycetes, relatively few studies have been conducted in subtropical forests of Southeast Asia, particularly in Northern Vietnam, where comprehensive reports of myxomycetes are lacking up to this date. Hence, a rapid biodiversity assessment was conducted in protected and unprotected plantation forests of Thai Nguyen City to compare the species composition of myxomycete communities between the two different forest management types.Methods – A total of 360 substrate samples were haphazardly collected within 5 m × 5 m plots established within three protected and three unprotected forests. The moist chamber cultures prepared from these samples were regularly checked for myxomycete fructifications over a period of 12 weeks. Analyses of diversity (species richness) and community composition were performed using the software EstimateS and the vegan package in R.Key results – The study yielded a total of 505 records representing 54 species belonging to 17 genera. All species recorded herein were new records for Northern Vietnam; among them five were new for the entire country. The rarefaction curves showed higher numbers of myxomycete species to be expected for protected forest (43.0) in comparison to unprotected forests (39.4). However, calculations of species diversity indices showed higher values in unprotected forest than in protected forest. The species composition between the two forest types showed clear overlaps with many shared (56%) species. Conclusions – Forest conservation strategies do not affect freely dispersing myxomycetes implicating that spore dispersal of myxomycetes is caused not only by natural factors but also by anthropogenic activities. The production of high number of myxomycete species for this study seems to point out that the subtropical forests of Vietnam harbours many undiscovered myxomycete species for Southeast Asia.

Evolutionarily distinct amphibians are disproportionately lost from human-modified ecosystems.

Humans continue to alter terrestrial ecosystems, but our understanding of how biodiversity responds is still limited. Anthropogenic habitat conversion has been associated with the loss of evolutionarily distinct bird species at local scales, but whether this evolutionary pattern holds across other clades is unknown. We collate a global dataset on amphibian assemblages in intact forests and nearby human-modified sites to assess whether evolutionary history influences susceptibility to land conversion. We found that evolutionarily distinct amphibian species are disproportionately lost when forested habitats are converted to alternative land-uses. We tested the hypothesis that grassland-associated amphibian lineages have both higher diversification and are pre-adapted to human landscapes, but found only weak evidence supporting this. The loss of evolutionarily distinct amphibians with land conversion suggests that preserving remnant forests will be vital if we aim to preserve the amphibian tree of life in the face of mounting anthropogenic pressures.

Columbus' environmental impact in the New World: Land use change in the Yaque River valley, Dominican Republic.

Columbus’ arrival in the New World in AD 1492 on the northern coast of Hispaniola was followed by a suite of changes in land-use. We reconstruct environmental change from a 225-cm-long sediment core from site Los Indios from an abandoned and sediment-filled meander of the Yaque River, Cibao Valley, northeastern Dominican Republic. The sediment record starts ca. AD 195 (ca. 1755 cal. yr BP) and the history of the meander infill was monitored by changing grain size distributions, organic matter concentration and pollen from wetland plants. From ca. AD 200 to ca. AD 1525, the pollen record indicates a diverse forest assemblage; however, the presence of pollen from potential crop plants suggest nearby small-scale subsistence crop cultivation. More abundant charcoal after ca. AD 1410 shows Amerindians increasingly used fire. The record of grain size distributions shows that the meander was temporarily part of a low energetic drainage system in which bedload and suspended sediments accumulated. After European colonization of Hispaniola increasing spores of coprophilous fungi evidence that Europeans had introduced during the first decades of colonization cattle in the Cibao Valley which gradually resulted in more open forest. The charcoal record around ca. AD 1650 reflects intensive forest clearing, suggesting that small-scale Pre-Colonial practice of crop cultivation became replaced by large-scale agriculture on the moist and nutrient rich soils along the Yaque River. Further deforestation and signals of erosion suggest that the population of colonists and introduced enslaved labour force must have increased rapidly. After ca. AD 1740 charcoal influx decreased suggesting that last deforestation activities used selective cutting to produce fire wood and timber for construction, rather than burning forest in situ. Two centuries after European colonization, by the 18th century, land-use within the Cibao Valley had become a balance between substantial livestock and crop cultivation (pollen grains have evidenced cereals, maize, and potentially also sugar cane, amaranthaceous crops and tobacco). After ca. AD 1950, swamp vegetation of Typha and Cyperaceae decreased, pointing to an almost fully terrestrialized meander with only few bodies of standing water, reflecting the present-day setting. This multiproxy reconstruction of anthropogenic environmental change shows a clear differentiation between an immediate introduction of livestock and after some 150 years the development of a European style agriculture, providing a context for archaeological investigations.

Weak environmental controls on the composition and diversity of medium and large‐sized vertebrate assemblages in neotropical rain forests of the Guiana Shield

AbstractAimDespite their often high‐trophic position and their contribution to many ecosystem functions, little is known about the factors affecting assemblage structure of medium‐ and large‐sized neotropical vertebrates. We examined the relative roles played by the physical and biological environment, and by purely spatial processes, in shaping the composition and diversities of these vertebrate assemblages. Then, based on the theory that the Guianan forest cover shrank to isolated pockets during the late Pleistocene–Holocene, we tested if the past forest refugia may have shaped current vertebrate assemblages.LocationFrench Guiana, Guiana Shield, South America.MethodsAbundances of 19 medium‐ and large‐sized vertebrates were estimated at 21 locations in undisturbed Guianan rain forests. Using taxonomic, functional and phylogenetic metrics, we partitioned the effects of a range of physical and biological environmental conditions and purely spatial predictors in shaping both assemblage composition and (alpha and beta) diversities.ResultsWe identified a significant, but weak relationship between taxonomic, functional and phylogenetic assemblage composition and environmental conditions. Assemblage diversity patterns were mainly explained by spatial predictors irrespective of the metrics. Current assemblage diversities are correlated with Pleistocene–Holocene forest history, with the highest alpha diversities outside of putative forest refugia, and the highest beta diversities inside these areas.Main conclusionsCurrent vertebrate assemblage composition is not strongly marked by common environmental factors. Our main conclusion is that assemblage composition results from individual species responses to the environment. Our findings also suggest that dispersal‐related processes or more probably historical processes shape (alpha and beta) diversity patterns. In fact, forest fragmentation during Pleistocene–Holocene climate changes could have led to isolated vertebrate assemblages evolving into unique species assemblages creating the current high beta diversity inside refugia, whereas the lower habitat stability outside of refugia could have led to mixed assemblages in areas recolonized by forest vertebrates (current high alpha diversity outside of refugia).

Dynamics and evolution of Turgay‐type vegetation in Western Siberia throughout the early Oligocene to earliest Miocene—a study based on diversity of plant functional types in the carpological record

AbstractBased on ecospectra of 66 published carpofloras we study dynamics and evolution of Turgay vegetation in Western Siberia during the early Oligocene to earliest Miocene. The ecospectra are obtained using a Plant Functional Type (PFT) classification system comprising 26 herbaceous to arboreal PFTs. The carpofloras originate from seven floristic levels covering the time‐span from the Rupelian to early Aquitanian. Key elements of these levels are documented based on original collection materials. Although impacted by local edaphic conditions, the ecospectra can be interpreted in terms of changing vegetation. Our data show that warm temperate mesophytic, mixed conifer‐broad‐leaved deciduous forest assemblages persisted throughout the Oligocene and earliest Miocene in this core area of Turgai type vegetation. This is in line with comparatively stable climate conditions persisting in the studied time‐span, showing a minor temperature decline and coeval moderate increase in seasonality and precipitation. Concurrently, the reconstructed ecospectra contradict significant continental drying throughout the Oligocene and earliest Miocene. Spatial variability of the proportions of PFTs within the single floristic horizons primarily reflects local edaphic conditions. High diversities of PFTs characteristic for swamp vegetation are mainly confined to the early Oligocene and have a regional focus. Our results indicate that taxonomical diversity, particularly concerning mesic herbs and deciduous shrubs and trees, increased towards the end of the Oligocene. This increase in biodiversity probably can be attributed to an increase in rainfall and extension of terrestrial habitats after the final retreat of the Paratethys.

Exploring multiple presence-absence data structures in ecology

Ecological studies may produce presence-absence data sets for different taxonomic groups, with varying spatial resolution and temporal coverage. Comparisons of these data are needed to extract meaningful information on the background ecological factors explaining community patterns, to improve our understanding of how beta diversity and its components vary among communities and biogeographical regions, and to reveal their possible implications for biodiversity conservation. A methodological difficulty is that the number of sampling units may be unequal: no method has been designed as yet to compare data matrices in such cases. The problem is solved by converting presence-absence data matrices to simplex plots based on the decomposition of Jaccard dissimilarity into species replacement and richness difference fractions used together with the complementary similarity function. Pairs of simplex plots representing different data matrices are then compared by quantifying, for each of them, the relative frequency of points in small, pre-defined subregions of the simplex, and then calculating a divergence function between the two frequency distributions. Given more than two data matrices, classification and ordination techniques may be used to obtain a synthetic and informative picture of metacommunity structure. We demonstrate the potential of our data analytical model by applying it to different case studies spanning different spatial scales and taxonomic levels (Mediterranean Island faunas; Finnish stream macroinvertebrate assemblages; Hungarian forest assemblages), and to a study of temporal changes in small islands (insect fauna in Florida). We conclude that, by accounting for various structural aspects simultaneously, the method permits a thorough ecological interpretation of presence-absence data. Furthermore, the examples illustrate succinctly how similarity, beta diversity and two of its additive components, species replacement and richness difference influence presence-absence patterns under different conditions.

Frost and leaf-size gradients in forests: global patterns and experimental evidence.

Explanations of leaf size variation commonly focus on water availability, yet leaf size also varies with latitude and elevation in environments where water is not strongly limiting. We provide the first conclusive test of a prediction of leaf energy balance theory that may explain this pattern: large leaves are more vulnerable to night-time chilling, because their thick boundary layers impede convective exchange with the surrounding air. Seedlings of 15 New Zealand evergreens spanning 12-fold variation in leaf width were exposed to clear night skies, and leaf temperatures were measured with thermocouples. We then used a global dataset to assess several climate variables as predictors of leaf size in forest assemblages. Leaf minus air temperature was strongly correlated with leaf width, ranging from -0.9 to -3.2°C in the smallest- and largest-leaved species, respectively. Mean annual temperature and frost-free period were good predictors of evergreen angiosperm leaf size in forest assemblages, but no climate variable predicted deciduous leaf size. Although winter deciduousness makes large leaves possible in strongly seasonal climates, large-leaved evergreens are largely confined to frost-free climates because of their susceptibility to radiative cooling. Evergreen leaf size data can therefore be used to enhance vegetation models, and to infer palaeotemperatures from fossil leaf assemblages.

Cannabis is indigenous to Europe and cultivation began during the Copper or Bronze age: a probabilistic synthesis of fossil pollen studies

Conventional wisdom states Cannabis sativa originated in Asia and its dispersal to Europe depended upon human transport. Various Neolithic or Bronze age groups have been named as pioneer cultivators. These theses were tested by examining fossil pollen studies (FPSs), obtained from the European Pollen Database. Many FPSs report Cannabis or Humulus (C/H) with collective names (e.g. Cannabis/Humulus or Cannabaceae). To dissect these aggregate data, we used ecological proxies to differentiate C/H pollen, as follows: unknown C/H pollen that appeared in a pollen assemblage suggestive of steppe (Poaceae, Artemisia, Chenopodiaceae) we interpreted as wild-type Cannabis. C/H pollen in a mesophytic forest assemblage (Alnus, Salix, Populus) we interpreted as Humulus. C/H pollen curves that upsurged and appeared de novo alongside crop pollen grains we interpreted as cultivated hemp. FPSs were mapped and compared to the territories of archaeological cultures. We analysed 479 FPSs from the Holocene/Late Glacial, plus 36 FPSs from older strata. The results showed C/H pollen consistent with wild-type C. sativa in steppe and dry tundra landscapes throughout Europe during the early Holocene, Late Glacial, and previous glaciations. During the warm and wet Holocene Climactic Optimum, forests replaced steppe, and Humulus dominated. Cannabis retreated to steppe refugia. C/H pollen consistent with cultivated hemp first appeared in the Pontic-Caspian steppe refugium. GIS mapping linked cultivation with the Copper age Varna/Gumelniţa culture, and the Bronze age Yamnaya and Terramara cultures. An Iron age steppe culture, the Scythians, likely introduced hemp cultivation to Celtic and Proto-Slavic cultures.

A survey of the weevils of Ukraine (Coleoptera: Curculionoidea).

The fauna of weevils Curculionoidea of Ukraine numbers 1453 species equivalent to 25.3% of European fauna. They belong to 10 families and 364 genera. A total of 51 species are recorded from Ukraine for the first time. Assessment of inventory completeness indicates that 62% of the area of Ukraine are covered by samples. Spatial join analysis has reveals strong collecting biases and shows maximal richness in cells which fall into well-sampled provinces. A total of 22 out of 33 studied model sites are well-sampled (C&gt;0.5). In total, we estimate ca.1470 species of Curculionoidea living in Ukraine. Curculionidae comprise the majority (82%) of the fauna, with 1202 species and 266 genera, and with remarkably high proportion of the three largest subfamilies: Entiminae (26%), Curculioninae (19%), and Ceutorhynchinae (18%). Consolidated data analysis shows highest richness (678-822 spp.) in provinces which fall into the mountain areas. Aggregated species richness for each of five ecoregions uncovers highest values in Pontic steppe (665 species) and East European forest-steppe (593 species). Habitat distribution of weevils is strongly uneven. Most of the richness (565 spp.) is harboured in lowland broadleaf forests. Salt marshes, salt steppes and sands are extreme habitats with low richness but high proportion of habitat specialists. Only 141 dominant species representing 18% of the total fauna but make up to 63% of the total population of weevils in Ukraine. Endemic species comprise a small proportion of the fauna but are remarkably concentrated in the mountains of Crimea (24 species) and the Carpathians (25 species). Along with 'true' endemics, 210 species are narrowly-ranged non-endemics and also have higher concentration in Crimea and the Carpathians (105 and 38 spp.). A total of 82 species are qualified as widely-ranged with high concentration in Central European Mixed Forests and East European Forest Steppe (71 spp. on average per province). The high diversity and evenness of weevil assemblages is shown by species sequence curve analysis in the Crimean Mountains, the Carpathians, steppes and lowland broad leaf forests, which contrasts with assemblages in lowland mixed forests. Shannon-Wiener and Simpson indices both show an extremely broad range of evenness in the Pontic Steppes which have both assemblages with low evenness in Stipa-Festuca-Koeleria steppes and high evenness in Stipa-Bromopsis steppes (H' =1.87-4.22). East European Forest Steppe and Central European Mixed Forests harbour similarly even communities (H' =3.60-4.48 vs. 3.18-4.57). The Crimean Mountains and the Carpathians are defined as a hotspot of biodiversity combining the highest scores of endemics, R1 species, and highest alpha diversity. Host plants are documented for 1259 species. Some 83% of weevils feed on live tissues of angiosperm plants belonging to 64 families. A total of 258 species are confirmed as polyphagous, 8 as monophagous, thus the majority of the rest are more or less narrowly oligophagous. A total of 33.68% of the species are associated with Fabaceae, Asteraceae, and Brassicaceae.

Animal occurrence in fragmented forest habitats – important factors at the patch and landscape scale

Abstract To date, in research, the main determinants influencing animal assemblages in fragmented forests have been considered to be forest island area and degree of isolation. Such a simplistic approach may have detrimental effects on the obtained results and conclusions, since there are a large number of other factors determining animal persistence in forest islands. In order to identify these factors and evaluate their importance, we reviewed the scientific literature on the topic. In addition to the island area, also patch shape, edge effects and local plant community structure are crucial factors affecting animal assemblages at the forest island scale. At the landscape scale, the total number of forest islands and their combined area, matrix permeability, occurrence of wide ecological corridors as well as isolated trees and woodlands appear to be the most significant factors. Our review further indicates that many of these elements also tend to interact. For instance, edge effects may reduce the area of suitable habitat in a forest patch. Furthermore, some fragmentation effects may be masked by species traits e.g. mobility, food preferences or habitat specialisation. The landscape context also plays a crucial role in animal persistence in fragmented forests. We thus conclude that there is a strong need to investigate the above-mentioned components of habitat fragmentation at the local and landscape scale using appropriate bio-indicators.

Impact of a hurricane on the herpetofaunal assemblages of a successional chronosequence in a tropical dry forest

AbstractLand‐use change is the main cause of deforestation and degradation of tropical forest in Mexico. Frequently, these lands are abandoned leading to a mosaic of natural vegetation in secondary succession. Further degradation of the natural vegetation in these lands could be exacerbated by stochastic catastrophic events such as hurricanes. Information on the impact of human disturbance parallel to natural disturbance has not yet been evaluated for faunal assemblages in tropical dry forests. To evaluate the response of herpetofaunal assemblages to the interaction of human and natural disturbances, we used information of pre‐ and post‐hurricane herpetofaunal assemblages inhabiting different successional stages (pasture, early forest, young forest, intermediate forest, and old growth forest) of dry forest. Herpetofaunal assemblages were surveyed in all successional stages two years before and two years after the hurricane Jova that hit the Pacific Coast of Mexico on October 2011. We registered 4093 individuals of 61 species. Overall, there were only slight effects of successional stage, hurricane Jova or the interaction between them on abundance, observed species richness and diversity of the herpetofauna. However, we found marked changes in estimated richness and composition of frogs, lizards, and snakes among successional stages in response to hurricane Jova. Modifications in vegetation structure as result of hurricane pass promoted particular changes in each successional stage and taxonomic group (anurans, lizards, and snakes). Secondary forests at different stages of succession may attenuate the negative effects of an intense, short‐duration, and low‐frequency natural disturbance such as hurricane Jova on successional herpetofaunal trajectories and species turnover.

Elevational patterns and ecological determinants of mean family age of angiosperm assemblages in temperate forests within Mount Taibai, China

Elevational patterns and ecological determinants of mean family age of angiosperm assemblages in temperate forests within Mount Taibai, China

Think twice before using narrow buffers: Attenuating mowing-induced arthropod spillover at forest – grassland edges

Spillover between agricultural land and natural habitats is recognised as an important mechanism shaping biodiversity and ecosystem functions. Its spatio-temporal patterns and magnitude are thoroughly described in the literature and it is often stated that spillover should be considered in conservation planning. In fact studies that implement and test active interventions to modulate spillover are scarce. Therefore, we studied the spillover of spiders and carabids between hay meadows and natural forests after mowing and tested whether leaving unmown buffer strips in the edges can mitigate undesirable aspects of mowing-induced spillover. We found that mowing affected the assemblages both in the meadows and forests and, interestingly, changes were more profound in the forests. Mowing reduced the spillover of forest assemblages into meadows. Mowing also led to the retraction of forest assemblages from the peripheral zones of forests but did not trigger an influx of meadow assemblages into the forests. Wide (10 m) unmown buffers attenuated or completely offset most of these effects. Leaving narrow (5 m) buffers had unexpected consequences, as they did not function only as buffers but as facilitators of forest-ward spillover from meadows, potentially compromising ecological interactions such as predation or competition in forests. We conclude that using wide buffers can be recommended as a refinement of standard management practices in hay meadow–forest mosaics. Narrow buffers should be applied with great caution and should generally be avoided if the forest-specific assemblages are of conservation interest.

Two decades of climate driving the dynamics of functional and taxonomic diversity of a tropical small mammal community in western Mexico.

Understanding the effects of global climate disruption on biodiversity is important to future conservation efforts. While taxonomic diversity is widely studied, functional diversity of plants, and recently animals, is receiving increasing attention. Most studies of mammals are short-term, focus on temperate habitats, and rely on traits described in the literature rather than generating traits from observations. Unlike previous studies, this long-term field study assessed the factors driving the functional and taxonomic diversity of small-mammal assemblages in dry tropical forests using both traits recorded from literature and a demographic database. We assessed the drivers (abundance and biomass, temperature and rainfall) of taxonomic richness and functional diversity for two rain-driven seasons in two adjacent but distinct forests—upland and lowland (arroyo or riparian) forests. Our analysis found that rainfall, both seasonal and atypical, was the primary factor driving functional and taxonomic diversity of small-mammal assemblages. Functional responses differed between the two types of forests, however, with effects being stronger in the harsher conditions of the upland forests than in the less severe conditions prevailing in the arroyo (riparian) forest. The latter also supports a richer, more diverse, and more stable small-mammal assemblage. These findings highlight the importance of climate to tropical biological diversity, as extreme climate events (hurricanes, droughts and floods) and disruption of rainfall patterns were shown to decrease biodiversity. They also support the need to preserve these habitats, as their high taxonomic diversity and functional redundancy makes them resilient against global climate disruption and local extreme events. Tropical dry forests constitute a potential reservoir for biodiversity and the ecosystem services they provide. Unfortunately, these forests are among the most endangered terrestrial ecosystems because of deforestation and the likely impacts of global climate disruption.

Spider assemblages in floodplain forests along an urbanization gradient

Urban areas have been growing radically worldwide, causing considerable changes in biodiversity of natural habitats. In floodplain forests, we studied the effects of urbanization on ground-dwelling spider assemblages along a rural-suburban—urban gradient in Hungary. We tested three traditional hypotheses (intermediate disturbance hypothesis, habitat specialist hypothesis and hygrophilous species hypothesis) and two novel expectations (shade-preferring species hypothesis, and disturbance sensitive species hypothesis) on spiders. We found that the total number of species was higher in the suburban habitat than in rural and urban ones, supporting the intermediate disturbance hypothesis. We found a decrease in the species richness of forest specialist and shade-preferring species along the urbanization gradient. We found that the number of hygrophilous and disturbance sensitive species was the lowest in the urban habitat. The spider assemblages of the rural and suburban habitats were clearly separated from the assemblages of urban habitats. Based on our findings we emphasize that low and moderate intensity of forest management contributes to the preservation of the local species richness in floodplain forests.

Relative contribution of neutral and deterministic processes in shaping fruit-feeding butterfly assemblages in Afrotropical forests.

The unified neutral theory of biodiversity and biogeography has gained the status of a quantitative null model for explaining patterns in ecological (meta)communities. The theory assumes that individuals of trophically similar species are functionally equivalent. We empirically evaluate the relative contribution of neutral and deterministic processes in shaping fruit‐feeding butterfly assemblages in three tropical forests in Africa, using both direct (confronting the neutral model with species abundance data) and indirect approaches (testing the predictions of neutral theory using data other than species abundance distributions). Abundance data were obtained by sampling butterflies using banana baited traps set at the forest canopy and understorey strata. Our results indicate a clear consistency in the kind of species or species groups observed at either the canopy or understorey in the three studied communities. Furthermore, we found significant correlation between some flight‐related morphological traits and species abundance at the forest canopy, but not at the understorey. Neutral theory's contribution to explaining our data lies largely in identifying dispersal limitation as a key process regulating fruit‐feeding butterfly community structure. Our study illustrates that using species abundance data alone in evaluating neutral theory can be informative, but is insufficient. Species‐level information such as habitat preference, host plants, geographical distribution, and phylogeny is essential in elucidating the processes that regulate biodiversity community structures and patterns.