查看更多>>摘要：? 2021 The AuthorsGiven the increasing threats to biodiversity and limited resources for conservation, our knowledge about the uncertainty in surrogates for representing comprehensively the spatial conservation priorities for biodiversity, needs to be improved. We present a comprehensive spatial conservation approach for Neotropical biodiversity by including surrogates for three biodiversity attributes: composition (8563 species), structure (663 ecosystems), and function (5382 ecological groups). We evaluated the differences in the representativeness and surrogacy-level of resulting portfolios for each attribute, considering the differences for current established conservation areas (CAs), prioritized areas (PRAs; those selected to complement the CAs), and total areas (TAs: CAs + PRAs). The assessment included the entire Neotropics, and a regionalization approach using the Global 200 Ecoregions by country. Finally, we identified critical areas for conservation based on the coincidence of irreplaceable PRAs among biodiversity attributes. Our results confirm the premise that no single surrogate represents biodiversity comprehensively, providing quantitative evidence to support the importance of using integrative information of surrogates for different levels of biodiversity into identifying priority areas for conservation. The spatial mismatch in the portfolios of areas shows how the use of a single level of biodiversity would lead to the omission of conservation priorities for other levels. We also identified critical areas for conservation where irreplaceable spatial priorities of the different biodiversity attributes matched. These areas coincided with known critical and threatened global biodiversity hotspots, and are mostly located in the Chaco, the Atlantic Forest, the Pantanal, Cerrado, and Caatinga regions, and the moist and dry forests of the northern Andes and Mesoamerica.
查看更多>>摘要：? 2021 Elsevier LtdWhen seeking prey, predators adaptively deploy strategies coarsely divided into sit-and-wait, sit-and-pursue, or active hunting modes. Though the hunting modes of many predators have been extensively studied, the implications of the hunting modes of human (Homo sapiens) predation are not yet fully understood. We conducted an extensive literature review to document human hunting modes and explore the ways in which these modes may shape animal populations via nonconsumptive effects (NCEs) of human predation. Among 169 studies published between 1972 and 2020, we found that humans used 27 hunting tools among 19 different hunting techniques when pursuing terrestrial prey. Most accounts described humans as using the active hunting mode (58%; n = 139 of 241), followed by the sit-and-wait hunting mode (41%; n = 98 of 241), and finally the sit-and-pursue hunting mode (2%; n = 4 of 241). While non-human predators tend to be evolutionarily adapted to the use of just one hunting mode, humans showed profound plasticity by deploying all three hunting modes in pursuit of prey species from 34 taxonomic orders spanning six orders of magnitude in body size (from 27 g to 4400 kg). Considerable evidence has documented the vast number of ways in which humans directly impact the functioning of the natural world. Our research complements that work by demonstrating the indirect pathways by which humans may affect animal populations and the landscapes over which these interactions occur, via NCEs deriving from the hunting modes of human predation, with important implications for animal conservation.
查看更多>>摘要：? 2021 Elsevier LtdEach year, millions of Palearctic waterbirds migrate between Eurasia and the wintering wetlands of the Sahel-Sahara region. International censuses show these populations are declining. Although hunting is recognised as the second cause of decline after habitat degradation along flyways, waterbird harvesting in the African wintering region remains overlooked. To fill this information gap, we conducted a hunting survey in the seven main Sahel-Saharan wetlands during the wintering season. Based on a socioeconomic, knowledge and off-take questionnaire, we estimated an annual harvesting level proxy per respondent. The results indicated that waterbird harvesting is a widespread practice in the research areas. Based on site, harvesting occurred from opportunistic and food off-take to specialised and commercial hunting. Rallidae and Anatidae were the targeted families, and Afrotropical species were more hunted than Palearctic species. Moreover, most of the targeted species had a “least concern” status in the IUCN red list of threatened species. Despite the high harvesting levels of the Malian and Egyptian sites, the total off-take seemed to occur at a lower level than at sites in Europe. This first survey conducted on this scale underlined that migratory waterbirds represent only a limited part of the food or income of the Sahel-Saharan human population. In order to secure both sustainable harvesting and environmental justice, international conservation efforts at the flyway level should implement a meaningful integration of Sahel-Saharan population cultural and subsistence needs and should engage all countries in a collaborative conservation and management approach across the entire migratory range.
查看更多>>摘要：? 2021 The AuthorsHimalayan forests are biodiverse and support the cultural and economic livelihoods of their human communities. They are bounded to the south by the Indo-Gangetic Plain, which has among the highest concentrations of atmospheric ammonia globally. This source of excess nitrogen pushes northwards into the Himalaya, generating concern that Himalayan forests will be impacted. To estimate the extent to which atmospheric nitrogen is impacting Himalayan forests we focussed on lichen epiphytes, which are a well-established bioindicator for atmospheric nitrogen pollution. First, we reviewed published literature describing nitrogen thresholds (critical levels and loads) at which lichen epiphytes are affected, identifying a mean and confidence intervals based on previous research conducted across a diverse set of biogeographic and ecological settings. Second, we used estimates from previously published atmospheric chemistry models (EMEP-WRF and UKCA-CLASSIC) projected to the Himalaya with contrasting spatial resolution and timescales to characterise model variability. Comparing the lichen epiphyte critical levels and loads with the atmospheric chemistry model projections, we created preliminary estimates of the extent to which Himalayan forests are impacted by excess nitrogen; this equated to c. 80–85% and c. 95–98% with respect to ammonia and total nitrogen deposition, respectively. Recognising that lichens are one of the most sensitive bioindicators for atmospheric nitrogen pollution, our new synthesis of previous studies on this topic generated concern that most Himalayan forests are at risk from excess nitrogen. This is a desk-based study that now requires verification through biological surveillance, for which we provide key recommendations.
查看更多>>摘要：? 2021Knowledge of demographic processes is essential for understanding population dynamics and developing appropriate conservation strategies under global change. However, it is often challenging to collect the necessary population and demographic data to understand population dynamics. Integrated population modeling (IPM) provides an opportunity to combine population survey and demographic data from different sources. We developed an IPM and applied it to jointly analyze 15 years (2004–2018) of regional North American Breeding Bird Survey and site-level capture-recapture and age-ratio data for a barn swallow (Hirundo rustica) population in Ontario, Canada. We aimed to identify key demographic parameters and tested hypothesized environmental drivers to understand population declines of this species. Our results showed that the study population had declined by about 2% annually during our study period, which was mainly contributed by changes in net immigration and adult apparent survival. In particular, low net immigration in a few years of our study period seemed to be the main reason of population decline. Furthermore, we found that warmer temperatures in April when barn swallows return to breeding grounds had a positive effect on adult survival, while warmer temperatures during the breeding period in May–June had a negative effect on productivity. Our results indicate vulnerability of the species to inclement weather during the breeding season, suggesting potential population recovery by adopting conservation strategies that buffer climatic threats. Moreover, our IPM provides a foundation for future monitoring programs that intend to combine and maximize the utility of large-scale population counts and fine-scale demographic data.
查看更多>>摘要：? 2021 Elsevier LtdUnlike most feral domestic animals, ranging behavior, diet dependence, and human socialization have been used as criteria to define feral dogs. These criteria can obstruct wildlife conservation if decisions depend on identifying ferality in dogs. We argue that diet dependence and human socialization are unnecessary to define ferality in situations where dogs constitute a threat to wildlife. Human-dependent diet and sociability are not exclusive to house dogs; thus, they do not differentiate ferality with certainty, and they have no established testing methods or thresholds. Most notably, they obstruct management by complicating feral dog identification. As a case study, legislation in Chile surrounding dog management does not recognize the existence of feral dogs and bans the application of lethal methods on dogs. This impairs conservation because the current definition makes it impossible to distinguish if a dog is feral at first sight. This is a problem in the small-scale livestock industry, where goat and sheep losses are mainly caused by dogs. Stakeholders could kill attacking dogs to defend their livestock, risking a lawsuit if those dogs were owned, or continue to lose their livelihood. Neither option benefits livestock owners. To not hinder conservation, we propose feral dogs be defined based only on ownership status, ranging behavior, and location in the context of management, and offer a classification based on these criteria. However, we contend that whether a dog is feral is not important for decision-making. Instead, dogs should be controlled if they are found on any public space unaccompanied by humans.
查看更多>>摘要：? 2021 Elsevier LtdLotic ecosystems harbor a disproportionate amount of global biodiversity, but continue to experience extinction rates greater than terrestrial. Alpine rivers and streams are especially threatened due to high rates of warming, glacier melt impacts, landcover change, and impoundment. Lack of monitoring, however, hampers conservation efforts in many regions. The Hindu-Kush Himalaya (HKH) is experiencing rapid environmental change, but impacts on aquatic biodiversity are unknown. Using a unique long-term dataset, we investigated changes to local (alpha) and regional (gamma) fish species diversity across 38 sites on Nepal's Kaligandaki-Narayani River (KNR), and evaluated potential impacts of climate change. Our results indicate a significant decrease in mean abundance and local species richness, although regional diversity did not decline. Species ranges contracted between the 1990s and 2010s, with lower bounds and weighted means shifting to higher elevations. Range shifts coincided with water temperature warming between the 1990s and 2010s, particularly at more speciose lower elevation sites. Although widespread species loss has not yet occurred, decreasing abundance and contraction of species' ranges point to increased extirpation risk in the near future. Our results suggest that effective conservation strategies must identify and preserve thermal refugia, maintain habitat connectivity, manage terrestrial protected areas so that aquatic biodiversity also benefits, and establish sustainable fishery harvests to protect species diversity in the KNR and other threatened, under-studied alpine biodiversity hotspots.
查看更多>>摘要：? 2021 Elsevier LtdQuantifying anthropogenic climate change vulnerability is essential for estimating the risk of species extinction and developing conservation strategies. The Magnolia genus is widespread in the Americas and Asia, with nearly half of species currently threatened. Here, we used climate-niche factor analysis to study the vulnerability of Magnolia species to future climate change. We found that the vulnerability of Magnolia species to future climate change is negatively related to range size. We further identified that narrow-ranged Magnolia species distributed in Asia are more vulnerable than those distributed in the Americas, with protected area coverage also lower in Asia than the Americas. Moreover, the conservation status ranking of Magnolia species classified by the IUCN Red List will likely be changed under climate change, as some Near Threatened and Least Concern species were estimated to be more vulnerable to climate change than species currently classified as Endangered. Our results highlight that conservation assessments, policies and actions need to consider spatial vulnerabilities of species to climate change.
查看更多>>摘要：? 2021Effective conservation planning often requires difficult decisions when at-risk species inhabit economically valuable landscapes or if the needs of multiple threatened species do not align. In the agriculture-dominated landscape of eastern Ontario and southwestern Quebec, Canada, conflicting habitat requirements exist between threatened grassland birds benefiting from certain agriculture practices, and those of a diverse woodland bird community dependent on forest recovery. Using multi-scale species distribution models with data from the North American Breeding Bird Survey (BBS), we assessed habitat suitability for 8 threatened grassland and forest specialists within this region. We also identified landscapes that jointly maximize occurrence of the 8 focal species and diversity of the full avian community. Influential habitat associations differed among species at the territory (200 m radius) and landscape level (1 km), highlighting the importance of considering multiple spatial scales. Species diversity was maximized when forest or grassland/pasture cover approached 40–50%, indicating a positive response to land cover heterogeneity. We identified species diversity hotspots near Lake Huron, as well as along the shore and southeast of the St. Lawrence River. These areas represent mosaic landscapes, balancing forest patches, wetland, grassland/pasture, and row crops such as corn, soybean, and cereals. Despite drastic landscape changes associated with agroecosystems, we demonstrate that targeted habitat protection and enhancement that prioritizes land cover diversity can maximize protection of bird communities with directly contrasting needs. We highlight multiple pathways to achieve this balance, including forest retention or separating row crops with hedgerows and wooded fence-lines, improving flexibility in conservation approaches.
查看更多>>摘要：? 2021 The AuthorsEcuador belongs to the megadiverse countries of the world. However, the high diversity in species, ecosystems and their services are under threat by land use changes, invasive species, overexploitation, pollution and climate change. There is a need to monitor, manage, protect and improve biodiversity and ecosystem services (BES) in Ecuador; however, Ecuador is marginally represented in the international policy-science interface for the protection of BES. We analyzed 266 international peer-reviewed papers that were published between 2000 and 2020 to assess the current impact of human disturbance and climate change on BES in continental Ecuador. We found that there were more studies available on the impact of human disturbance on BES than on climate change effects. Birds represented the most studied taxon in Ecuador (70 studies), whereas the total amount of available international scientific publications for other Ecuadorian plant and animal taxa were rather low (< 34 studies) and spatially and thematically scattered. Among ecosystem services, water provision was analyzed relatively often. Our literature review revealed that there is a need to conduct more studies on impacts of human disturbance and climate change on BES. Further research is needed; particularly in the coastal hinterland, in the central Andes and in the Amazon. We suggest that the investment of time, resources and effort into the documentation, standardization, sharing, and publishing of data are key towards supporting the monitoring and maintenance of BES.
NSTL
Elsevier