Basic and Applied Ecology最新文献

The broad negative effects of land-use conversion for agriculture on wildlife species are well known, but few studies have evaluated how different land-use types impact spatiotemporal patterns and trophic strategy of large carnivores. We conducted sign surveys for the Asiatic black bear, a critically endangered subspecies in southeastern Iran. We applied Bayesian occupancy modelling and quantified spatiotemporal determinants of black bear occurrence as a function of date palms, distance to agriculture, elevation, precipitation, and protected area (PA) size. We also investigated its diet composition based on scat (n = 150) analyses. Date palm area size (β = 2.07; 95 % Credible Interval = 0.67 to 3.89) and distance to croplands had a strong and significant (β = −1.06, 95 % CrI = −2.10 to −0.20) influence on the occupancy. Elevation, precipitation, village density, and PA size did not substantially influence occupancy. Black bear detection probability became 100 % only above 14 km survey effort, indicating its overall rarity, and bears were much more easily detected during and after rainfall. Bears mainly relied on date palms (41 %) followed by herbaceous plants (24.6 %), insects (15 %), wild mammals (6.4 %), wild fruits (5.6 %), livestock (4.9 %) and other vertebrates (2.5 %, e.g., birds). Most of the predicted bear occupancy was outside PAs and thus suggests a high likelihood of human-bear conflicts. Presumably, resource density is insufficient to support bears inside PAs, but information concerning resource density is currently lacking. Our results showed that the agricultural landscape provided an important feeding (46 %) area for bears. Consequently, effective conservation programs such as the protection of abandoned date palm groves as a conflict-free food source are necessary. Practical training such as protective measures against crop-raiding behavior of bears would be essential to foster the tolerance of people toward bears and thus can help facilitate coexistence.

Understanding patterns of species-genetic diversity correlations (SGDC) is important for conservation purposes because it allows us to infer whether conservation of species diversity (SD) influences conservation of genetic diversity (GD) and the other way around. Here, we studied SGDCs using aquatic macrofauna in a set of 31 urban ponds in the metropolitan area of Stockholm, Sweden. We also estimated how land use and pond environmental factors affect SD and GD. SD was estimated as species richness. GD was estimated in four focal species that differed in their dispersal abilities: Asellus aquaticus (Isopoda), Haliplus ruficollis (Coleoptera), Planorbis planorbis (Gastropoda), Rana temporaria (Amphibia), using double digest restriction associated DNA (ddRAD) sequencing data. There were no significant SGDCs for any of the species. Similarly, GD was not related to land use or pond environment. However, SD had a significant positive correlation with total invertebrate abundance and pond area. Given the absence of significant SGDCs in our study, and the mixed positive and negative patterns found in previous studies reporting SGDCs, we suggest that simultaneously preserving species and genetic diversity in urban areas will prove challenging.

In livestock management systems, the rapid removal of cattle dung by dung beetles plays an essential role in returning areas of pasture to grazing which normally would be lost because of dung contamination. Thus, dung removal is an ecosystem process with established links to services with potentially valuable outcomes. We focused on dung removal under two dung beetle abundance scenarios. We then calculated the economic value of dung beetle action on dung degradation in US sub-tropical pasturelands under each scenario by measuring the costs associated with restriction of new forage growth by dung pat smothering, and the amount of forage gained because of dung beetle mediated dung decomposition. We found if dung is left unmanipulated by dung beetles, it would naturally decompose at an average rate of 3.75 g per day, and dung in pastures with a high abundance of dung beetles would decay at 10.73 g per day. We show the economic benefit of dung decomposition under each scenario is directly related to both the presence and abundance levels of dung beetles in cattle pastures, for instance, resulting in additional grass area to become available to raise 1,131 cows and 1,676 cows under low dung beetle abundances and under high dung beetle abundances, respectively. This amounts to an additional income of USD 918,688 per year in Florida sub-tropical livestock systems containing low abundances of dung beetles and an income of USD 1,360,770 per year for pastures sustaining a higher abundances of dung beetles. Despite their importance in livestock systems dung beetle populations are imperiled by the widespread use of agrochemicals. Reducing agrochemical usage and introducing biodiversity-friendly practices in livestock systems will be important for conserving dung beetles and the ecological functions that dung beetles provide in working landscapes.

Modern approaches with advanced technology can automate and expand the extent and resolution of biodiversity monitoring. We present the development of an innovative system for automated wildlife monitoring in a coastal Natura 2000 nature reserve of the Netherlands with 65 wireless 4G wildlife cameras which are deployed autonomously in the field with 12 V/2A solar panels, i.e. without the need to replace batteries or manually retrieve SD cards. The cameras transmit images automatically (through a mobile network) to a sensor portal, which contains a PostgreSQL database and functionalities for automated task scheduling and data management, allowing scientists and site managers via a web interface to view images and remotely monitor sensor performance (e.g. number of uploaded files, battery status and SD card storage of cameras). The camera trap sampling design combines a grid-based sampling stratified by major habitats with the camera placement along a traditional monitoring route, and with an experimental set-up inside and outside large herbivore exclosures. This provides opportunities for studying the distribution, habitat use, activity, phenology, population structure and community composition of wildlife species and allows comparison of traditional with novel monitoring approaches. Images are transferred via application programming interfaces to external services for automated species identification and long-term data storage. A deep learning model for species identification was tested and showed promising results for identifying focal species. Furthermore, a detailed cost analysis revealed that establishment costs of the automated system are higher but the annual operating costs much lower than those for traditional camera trapping, resulting in the automated system being >40 % more cost-efficient. The developed end-to-end data pipeline demonstrates that continuous monitoring with automated wildlife camera networks is feasible and cost-efficient, with multiple benefits for extending the current monitoring methods. The system can be applied in open habitats of other nature reserves with mobile network coverage.

Winter is a critical period for the survival of local bird species in temperate regions. Some wintering birds may rely on transient food, such as that provided at birdfeeders, but bird communities around birdfeeders may also attract predators. However, these effects of birdfeeders on interspecific interactions between birds and their predators remain largely unexplored and have so far not been tested experimentally. We hypothesized that birdfeeders indirectly attract predators in winter because of the attraction of small birds, and tested this hypothesis using experimental feeders at 52 different urban and rural sites across western Poland. We found that the number of small birds increased around birdfeeders, particularly those with provided food. We found that birdfeeders that attracted more small birds (regardless of whether they provided food) attracted also more predators, such as sparrowhawks Accipiter nisus and feral cats Felis domesticus. Moreover, birdfeeders in urban habitats attracted relatively fewer small birds but not fewer predators compared to those in rural areas. Altogether, birdfeeders with food provided attracted small prey birds but they attracted also more predators, whose presence may hinder small birds from fully utilizing available resources, potentially impacting their winter survival through direct (mortality) and indirect (increased monitoring and vigilance) effects.

Urban areas can be both detrimental for pollinators or function as suitable habitats, depending on the land-use type, the urban context and the pollinator group in focus. Urban green spaces, including gardens, parks or cemeteries can provide essential resources for a wide range of pollinator groups, like wild bees, hoverflies and beetles. Urban community gardens can be particularly structurally complex and harbour a diverse range of nesting and food resources for pollinators. However, we know little about how garden features may vary with the urban context of gardens and which specific garden features can increase the abundance of pollinators in general and of different pollinator groups.

Over two summer seasons, we recorded garden features and pollinators using flower observations in 33 urban community gardens in Munich and Berlin, Germany. We examined how garden features differ amongst urban community gardens from three urbanisation categories, and analysed the effects of garden features such as floral and nesting resources and landscape imperviousness (as indicator of urbanisation) on pollinator abundance, richness and diversity.

In more urbanised gardens, flower richness and bare substrate were less prevalent. Flower richness was positively correlated with overall pollinator abundance, richness and diversity as well as with the abundances of all pollinator taxa excluding beetles. Landscape imperviousness was negatively correlated with hoverfly and beetle abundances. Hoverflies also decreased with increasing bare substrate and wasp abundance decreased with increasing deadwood availability. Our findings highlight the important role of flower richness for insect conservation in urban management and show that pollinator taxa react differently to garden features and urbanisation. To support pollinating insects, gardeners can increase flower richness, especially in highly urbanised areas.

In the context of worldwide biodiversity and wild bee decline, it is increasingly important to better understand the effect of land-use changes on wild bee communities at a global scale. To do so, we studied the effect of city area and urban green spaces layout on wild bee species richness and community composition, as well as on wild bee species with an unfavorable UICN conservation status. This study was based on a large European dataset encompassing 20 cities from France, Belgium and Switzerland. We found a mean wild bee species richness in cities of 96 ± 48 (SD), showing that this species richness was highly variable among cities. The main factor positively influencing wild bee species richness in cities was the area of the city. Conversely, species richness was not significantly related to the total area of urban green spaces in a given city, measured as the spatial extent of urban parks, wastelands and other semi-natural habitats, excluding urban private gardens. Species with conservation status were quite scarce in urban environments, especially when compared to the European Red List of Bees, and we could not link their presence to either city or urban green space area. Dissimilarities in wild bee species community compositions were not associated with any of the studied characteristics of cities. We found that the dissimilarity of wild bee community composition among cities was mainly driven by the rarest species, as the most common ones were found in a majority of the cities sampled. Overall, these results emphasize that larger cities host more wild bee species, but are no refuge for the ones with concerning conservation status. Thus, stakeholders are encouraged to design their cities in favor of biodiversity to better support wild bee communities, and perhaps mitigate the established effect of the urban ecological filter.

To successfully conserve and restore agrobiodiversity, it is essential to understand the impact of multiple drivers and interlinkages across multiple taxa that occur above, across, and below the soil interface. Based on data from six agricultural landscapes in Central Germany, with 16 sampling plots per landscape, we used structural equation models to disentangle the impacts of climate, land-use, and soil factors on the diversity of multiple taxonomic groups. We expected belowground communities (soil bacteria and fungi) to be more driven by soil variables, mobile aboveground groups (wild bees, ground beetles) to be more driven by climate and land use, and vascular plants, that have an above- and belowground component, to respond to a combination of all factors.

According to our expectations, climate and land-use variables had an important role in shaping aboveground and plant communities. In contrast to our expectations, soil characteristics were of lesser importance for belowground organisms. Moreover, climatic factors had a strong impact on the soil microbiome, but this effect was indirect, modulated by soil pH. We also found indications for cascading effects of environmental factors via interlinkages within and among the above- and belowground communities. Our results highlight the importance of direct and indirect effects of multiple drivers on the diversity of multiple taxonomic groups and support recent calls for a multifunctional approach for sustainable landscape management and nature restoration, suggesting to focus on the promotion of semi-natural habitats but also considering the climatic context.

Allochthonous inputs often link nutrient cycles between different ecosystems as nitrogen (N) that originates in one ecosystem is transferred to another. Mobile animals such as birds and fish can translocate nutrients between locations. Consequently, animal-mediated nutrient subsidies can shape plant communities, especially in nutrient-poor ecosystems. Terrestrial cliffs are typically nutrient-poor, receiving N from atmospheric deposition and cliff-top runoff. Cliff nesting birds deposit N-rich excrement onto the cliff during nesting, yet this potential nutrient input has rarely been demonstrated. Here we document an allochthonous input of N from cliff-nesting birds to terrestrial cliff vegetation. We sampled mineral N and vegetation on eight cliff systems in western North Carolina (USA) with nests from peregrine falcon (F. peregrinus; two sites) and common raven (Corvus corax; five sites). Two sites had nests but species identity was not confirmed. Cliff faces below bird nests had higher levels of ammonium (NH₄⁺) than did faces without nests. Both ammonium and nitrate (NO₃⁻) explained variability in cliff vegetation community composition, but site-level characteristics explained more of the variation than did N inputs alone. Lichens, the dominant taxonomic group, contributed the most to this variation and had higher species richness and diversity below nests. Indicator species analysis identified two nitrophilic lichen species below nests: Flavoplaca citrina and Physcia caesia. A third nitrophilic lichen, Polycauliona candelaria (syn. Xanthoria candelaria) was also found under nests. Bird excrement is likely a significant subsidy to nutrient-poor terrestrial cliff ecosystems, thus linking cliffs to more productive ecosystems and highlighting the need to include birds in conservation and management of cliffs.

Intensively managed viticulture dominates vast landscapes in the Mediterranean, but considerable vineyard abandonment has been observed over the past two decades. The effect of vineyard abandonment on biodiversity is poorly understood, making it difficult to assess the restoration potential of this common land-use change.

We assessed biodiversity responses to vineyard abandonment in Vaucluse, Southern France, using birds as indicator group. We compared bird abundance and diversity in a sample of 64 vineyards, pairing 16 currently managed vineyards with 16 recently abandoned and 16 managed with 16 longer abandoned vineyards. We used mixed models and multivariate techniques to establish relationships between bird diversity and structural attributes of the habitats, and we derived management-specific population densities in a distance sampling approach.

Long-abandoned vineyards hosted three times more species and showed a 3.6 times higher total bird abundance than managed viticulture. More recently abandoned vineyards had intermediate species numbers and abundance. Species richness patterns were not modulated by landscape composition and configuration, but higher abundances were found in landscapes with intermediate size of land-cover patches (i.e. field size). In managed vineyards, bird abundances were extremely low, with the exception of Woodlark Lullula arborea, which reached its highest abundance in managed vineyards. The bird community on abandoned vineyards shifted towards forest and woodland shrub species, likely driven by secondary succession, namely shrub encroachment and tree establishment.

The strongly positive effects of land abandonment might be due to the fact that only single vineyards (not entire landscapes) were abandoned, thereby increasing habitat heterogeneity at the landscape scale. The future state of the old abandoned vineyards is difficult to predict. As of yet, the abandoned vineyards support a comparably diverse community of breeding birds that reach high abundances in comparison to managed vineyards, within an otherwise impoverished agricultural landscape.