Conservation effectiveness of protected areas for Hong Kong butterflies declines under climate change

Protected areas are important in conserving the rapid decline of biodiversity in the Anthropocene. Yet uncertainty persists whether protected areas will continue to meet conservation goals if climate change causes community or ecosystem shifts. Previous research has proven equivocal with some studies finding protected areas fail conservation objectives and others finding objectives are largely met. The effectiveness of protected area systems within tropical Asia and for insects are particularly under-studied. Using species distribution modeling of 68 butterfly species (15,346 locality records), we carried out an evaluation of the effectiveness of protected areas in Hong Kong, one of the most well-covered (40% land area) protected area systems in the Asian tropics, and projected how the ability to protect biodiversity would change under different climate change scenarios and different conservation target schemes. Under climate change, 15–37% of the modeled species in 2000 were projected to become extirpated by 2050. Under all conservation target schemes, the proportion of species unprotected increased or leveled, by up to as much as 7%. If buffer grids were considered as unprotected, the increase in these gap species was much greater, by up to as much as 22%. These results together indicate that under climate change, the effectiveness of protected areas for butterflies in Hong Kong is likely to decrease despite the territory’s relatively high proportion of protected area coverage. We also highlight here the importance of the fortification of partly protected areas in mediating biodiversity loss under the impacts of global change.     

Bird assemblages of intensively established pine plantations in Coastal Plain Mississippi

Pine (Pinus spp.) plantations are a common type of managed forest in the southeastern United States that may supply habitat for early successional bird species, many of which are declining. To provide information about young pine plantations as bird habitat, we evaluated spring bird presence in 5 combinations of stand establishment practices during years 2 through 5 post-establishment in the Lower Coastal Plain of Mississippi, USA. We detected 38 species with point counts and compared bird metrics among establishment practices using mixed general linear models. Species richness, total relative abundance, and relative abundance of many species were greater by at least a factor of 1.5–4 in the chemical-only establishment practice than mechanically prepared establishment practices, and values declined by about 5–60% within mechanically prepared establishment practices as herbicide intensity increased. Tree and snag retention contributed to avian abundance and richness in the chemical-only establishment practice. Our study, in conjunction with past research, demonstrated the conservation value to early successional bird species of managed pine stands established with tree retention, indicating that silvicultural and wildlife habitat objectives can be met within the range of stand establishment treatments available to managers. © 2012 The Wildlife Society.     

Evidence for decline in eastern North American bumblebees (Hymenoptera: Apidae), with special focus on <Emphasis Type="Italic">Bombus affinis</Emphasis> Cresson

Bumblebees (Bombus spp.) have been declining rapidly in many temperate regions of the Old World. Despite their ecological and economic importance as pollinators, North American bumblebees have not been extensively surveyed and their conservation status is largely unknown. In this study, two approaches were used to determine whether bumblebees in that region were in decline spatially and temporally. First, surveys performed in 2004–2006 in southern Ontario were compared to surveys from 1971 to 1973 in the same sites to look at changes in community composition, in one of the most bumblebee diverse areas of eastern North America. Second, the extent of range decline for a focal species (Bombus affinis Cresson) was estimated by surveying 43 sites throughout its known native range in eastern Canada and the United States. Our study documents an impoverishment of the bumblebee community in southern Ontario over the past 35 years. Bombus affinis in particular was found to have declined drastically in abundance not only in southern Ontario but throughout its native range. The loss of any bumblebee species may result in cascading impacts on native fauna and flora and reduce agricultural production. Implications for the conservation of this important group of pollinators are discussed.     

Exploring the spatiotemporal dynamics of habitat suitability to improve conservation management of a vulnerable plant species

Ongoing declines in biodiversity caused by global environmental changes call for adaptive conservation management, including the assessment of habitat suitability spatiotemporal dynamics potentially affecting species persistence. Remote sensing (RS) provides a wide-range of satellite-based environmental variables that can be fed into species distribution models (SDMs) to investigate species-environment relations and forecast responses to change. We address the spatiotemporal dynamics of species’ habitat suitability at the landscape level by combining multi-temporal RS data with SDMs for analysing inter-annual habitat suitability dynamics. We implemented this framework with a vulnerable plant species (Veronica micrantha), by combining SDMs with a time-series of RS-based metrics of vegetation functioning related to primary productivity, seasonality, phenology and actual evapotranspiration. Besides RS variables, predictors related to landscape structure, soils and wildfires were ranked and combined through multi-model inference (MMI). To assess recent dynamics, a habitat suitability time-series was generated through model hindcasting. MMI highlighted the strong predictive ability of RS variables related to primary productivity and water availability for explaining the test-species distribution, along with soil, wildfire regime and landscape composition. The habitat suitability time-series revealed the effects of short-term land cover changes and inter-annual variability in climatic conditions. Multi-temporal SDMs further improved predictions, benefiting from RS time-series. Overall, results emphasize the integration of landscape attributes related to function, composition and spatial configuration for improving the explanation of ecological patterns. Moreover, coupling SDMs with RS functional metrics may provide early-warnings of future environmental changes potentially impacting habitat suitability. Applications discussed include the improvement of biodiversity monitoring and conservation strategies.     

The Conservation Value of Small Fragments For Atlantic Forest Reptiles

Loss and fragmentation of natural habitats are key contributors to the decline of populations and impoverishment of biological communities. The response to these disturbances can vary substantially among taxa and depends on spatial metrics of habitat fragments and the surrounding landscape. Herein we test how fragment area, shape, isolation, and matrix quality affect reptile richness, abundance, and occurrence in Brazilian Atlantic Forest fragments, a biodiversity hotspot with a poorly studied reptile fauna. We used 23 forest fragments, ranging from 2 to 30 hectares, surrounded by different matrix types, including sugarcane crop fields, cattle ranching, subsistence farmlands and rural communities. Species richness, total reptile abundance, population abundance, and occurrence probability of many species decreased with fragment area. Model selection suggested that fragment area is the main predictor of both richness and abundance, but matrix quality as well as fragment shape are also important predictors. For population abundance and occurrence probability, fragment area and proximity were the most important predictors followed by fragment shape and matrix quality, but the strength and even the sign of predictors varied substantially among species. We highlight that the value of small fragments should not be neglected for the conservation of Atlantic Forest reptiles.     

Using the IUCN Red List to determine effective conservation strategies

Threatened species lists continue to grow while the world’s governments fail to meet biodiversity conservation goals. Clearly, we are failing in our attempts to conserve biodiversity. Yet 37 mammal species genuinely improved in status in the 2009 IUCN Red List, suggesting there are ways to successfully conserve biodiversity. Here, I compare the threats and conservation actions (proposed and implemented) by the expert assessors of the Red List of improving species to a further 144 declining mammal species to determine whether specific threats were more easily remedied, and whether certain conservation actions were more successful than others. Declining species were faced with different threatening processes to mammals improving in status suggesting some threats were easier to treat (e.g. hunting) than others (climate change, invasive species). Declining species had different proposed and implemented conservation actions than improving species suggesting some actions are more successful than others. Threatened species were invariably found in conservation areas, suggesting protected area creation alone is not an overly successful strategy for species at risk of extinction. Conservation actions were more frequently implemented for improving than declining species suggesting active conservation is effective in improving the status of biodiversity. There were significant differences between proposed and implemented conservation actions suggesting some actions are easier to implement than others. Reintroduction, captive breeding and hunting restriction were more effective in conserving mammals than site creation and invasive species control. These findings highlight effective conservation actions for mammals worldwide and allow the rationalisation of threat mitigation measures to ensure economically justifiable biodiversity conservation strategies.     

Evaluating the effectiveness of overstory cover as a surrogate for bird community diversity and population trends

Landscape features are often used as surrogates for biodiversity. While landscape features may perform well as surrogates for coarse metrics of biodiversity such as species richness, their value for monitoring population trends in individual species is virtually unexplored. We compared the performance of a proposed habitat surrogate for birds, percentage cover of vegetation overstory, for two distinct aspects of bird assemblages: community diversity (i.e. species richness) and population trends. We used four different long-term studies of open woodland habitats to test the consistency of the relationship between overstory percentage cover and bird species richness across a large spatial extent (>1000 km) in Australia. We then identified twelve bird species with long-term time-series data to test the relationship between change in overstory cover and populations trends. We found percentage cover performed consistently as a surrogate for species richness in three of the four sites. However, there was no clear pattern in the performance of change in percentage cover as a surrogate for population trends. Four bird species exhibited a significant relationship with change in percentage overstory cover in one study, but this was not found across multiple studies. These results demonstrate a lack of consistency in the relationship between change in overstory cover and population trends among bird species, both within and between geographic regions. Our study demonstrates that biodiversity surrogates representing community-level metrics may be consistent across regions, but provide only limited information about individual species population trends. Understanding the limitations of the information provided by a biodiversity surrogate can inform the appropriate context for its application.     

Ecoregion Prioritization Suggests an Armoury Not a Silver Bullet for Conservation Planning

In the face of accelerating species extinctions, map-based prioritization systems are increasingly useful to decide where to pursue conservation action most effectively. However, a number of seemingly inconsistent schemes have emerged, mostly focussing on endemism. Here we use global vertebrate distributions in terrestrial ecoregions to evaluate how continuous and categorical ranking schemes target and accumulate endangered taxa within the IUCN Red List, Alliance for Zero Extinction (AZE), and EDGE of Existence programme. We employed total, endemic and threatened species richness and an estimator for richness-adjusted endemism as metrics in continuous prioritization, and WWF''s Global200 and Conservation International''s (CI) Hotspots in categorical prioritization. Our results demonstrate that all metrics target endangerment more efficiently than by chance, but each selects unique sets of top-ranking ecoregions, which overlap only partially, and include different sets of threatened species. Using the top 100 ecoregions as defined by continuous prioritization metrics, we develop an inclusive map for global vertebrate conservation that incorporates important areas for endemism, richness, and threat. Finally, we assess human footprint and protection levels within these areas to reveal that endemism sites are more impacted but have more protection, in contrast to high richness and threat ones. Given such contrasts, major efforts to protect global biodiversity must involve complementary conservation approaches in areas of unique species as well as those with highest diversity and threat.     

Plant species composition in relation to green cover configuration and function of urban parks in Beijing, China

Parks, as one specific type of urban open space, play important roles in the conservation of urban biodiversity and provision of recreational services for local residents. As there is a lack of specific insight into park plant species composition in relation to park features, 24 sample parks within the inner city of Beijing, the capital of China, were studied by stratified random plot sampling of their tree, shrub, and herbaceous communities, respectively, in order to investigate how human activities have influenced park green cover configuration and floristic characteristics. The quantitative correlation of species richness and the park green cover indices (patch size, shape, etc.) were studied. The importance value index for plant species (trees, shrubs, and herbaceous species) of each park was calculated. The two-way indicator species analysis approach (TWINSPAN) was applied to classify the 24 parks into different groups based on their species assemblages. Two-hundred and eighty-eight species were recorded within the 24 study parks, belonging to 184 genera and 72 families dominated by Gramineae, Compositae, and Leguminosae. Among all the recorded species, 41% are exotic. The species occurrence, abundance and diversity vary significantly among different parks. Besides the positive correlation (R=0.505, P<0.05) between herbaceous species abundance and the park green cover size, no other significant relations were found between the species abundance and other indices of park green cover configuration. Remarkably, the TWINSPAN classification resulted in a good discrimination between park functional types and the variation in their species assemblage. For the parks of similar age (development history) or landscape design, their species assemblages show more similarity. The methodology adopted and results can be employed to improve baseline information on urban plant ecology and support the setting of priorities for future park management and vegetation protection.     

Flight areas of British butterflies: assessing species status and decline

Geographical range size is a key ecological variable, but the consequences of measuring range size in different ways are poorly understood. We use high-resolution population data from British butterflies to demonstrate that conventional distribution maps, widely used by conservation biologists, grossly overestimate the areas occupied by species and grossly underestimate decline. The approximate flight areas occupied by 20 out of 45 colonial British species were estimated to cover a median of only 1.44% of the land surface within occupied regions. Common species were found to be declining faster than conventional distribution maps suggest: common and rare species had no significant difference in their population-level rates of extinction. This, combined with the log-normal form of the range-size frequency distribution, implies that species-level extinction rates may accelerate in the medium to long term. Population-level conservation is a matter of great urgency for all species, not just for the rarest.     

A comparative measure of biodiversity based on species composition

In conservation planning, species richness and species endemism are the most often used metrics for describing the biodiversity importance of areas. However, when it comes to prioritizing regions for conservation actions these measures alone are insufficient because they do not reveal how similar or different the actual composition of species may be from one area to another. For comparative analysis an additional useful metric would be one that indicates the degree to which the species assemblage in one area is also represented in—or is distinct from—species assemblages of other areas. Here we describe a method for quantifying the compositional representativeness of species assemblages among geographic regions. The method generates asymmetric pairwise similarity coefficients that are then used to calculate separate measures for the representativeness and the distinctiveness of species assemblages in the regions being compared. We demonstrate the method by comparing fish communities among freshwater ecoregions of the Mississippi Basin, and then among smaller hydrological units within two individual freshwater ecoregions. At both scales of analysis, our measures of representativeness and distinctiveness reveal patterns of fish species composition that differ from patterns of species richness. This information can enhance conservation planning processes by ensuring that priority-setting explicitly consider the most representative and distinctive species assemblages.     

Common European birds are declining rapidly while less abundant species' numbers are rising

Biodiversity is undergoing unprecedented global decline. Efforts to slow this rate have focused foremost on rarer species, which are at most risk of extinction. Less interest has been paid to more common species, despite their greater importance in terms of ecosystem function and service provision. How rates of decline are partitioned between common and less abundant species remains unclear. Using a 30‐year data set of 144 bird species, we examined Europe‐wide trends in avian abundance and biomass. Overall, avian abundance and biomass are both declining with most of this decline being attributed to more common species, while less abundant species showed an overall increase in both abundance and biomass. If overall avian declines are mainly due to reductions in a small number of common species, conservation efforts targeted at rarer species must be better matched with efforts to increase overall bird numbers, if ecological impacts of birds are to be maintained.     

The impact of raptors on the abundance of upland passerines and waders

The issue of predator limitation of vertebrate prey populations is contentious, particularly when it involves species of economic or conservation value. In this paper, we examine the case of raptor predation on upland passerines and waders in Scotland. We analysed the abundance of five wader and passerine species on an upland sporting estate in southern Scotland during an eight-year period when hen harrier, peregrine and merlin numbers increased due to strict law enforcement. The abundance of meadow pipit and skylark declined significantly during this time. Golden plover also showed a declining trend, whereas curlew increased significantly and there was a near significant increase in lapwings. Contrasting the local population trends of these species with trends on nearby areas revealed higher rates of decline for meadow pipit and skylark at the site where raptors increased, but no differences in trends for any of the three wader species. There was a negative relationship between the number of breeding harriers and meadow pipit abundance the same year and between total annual raptor numbers and meadow pipit abundance. Predation rates of meadow pipit and skylark determined from observations at harrier nests suggested that predation in June was sufficient to remove up to 40% of the June meadow pipit population and up to 34% of the June skylark population. This 'quasi-natural' experiment suggests that harrier predation limited the abundance of their main prey, meadow pipit, and possibly the abundance of skylark. Thus, high densities of harriers may in theory reduce the abundance of the prey species which determine their breeding densities, potentially leading to lower harrier breeding densities in subsequent years. We found no evidence to suggest that raptor predation limited the populations of any of the three wader species. We infer that concerns over the impact of natural densities of hen harriers on vulnerable upland waders are unjustified.     

Conservation targets for viable species assemblages?

Estimates of minimum areas required for effective biodiversity conservation differ substantially. Scientific reserve design and placement procedures indicate that between 30 and 75% of any region may be required to sample biodiversity features. These estimates do not routinely incorporate measures for sampling viable populations of species or explore the area requirements of sampling viable populations of species assemblages. To determine the area requirements for sampling viable populations of a herbivore assemblage, spatially explicit abundance data from the Kruger National Park, South Africa, were analyzed. Area requirements were consistently above 50% and were unaffected by selected target population sizes. In addition, area requirements appeared to be insensitive to selection unit size (analytical grain), habitat quality, the coarseness of the land classification system used or the presence of low-density species. Thus, traditional conservation area targets of 10–15% appear inadequate for representing viable populations of a herbivore assemblage from African savanna regions. This suggests that conservation targets of at least 50% of land classification units may represent a more appropriate conservation rule of thumb, or alternatively, that the use of data independent conservation targets may need to be abandoned.     

Temporal turnover and the maintenance of diversity in ecological assemblages

Temporal variation in species abundances occurs in all ecological communities. Here, we explore the role that this temporal turnover plays in maintaining assemblage diversity. We investigate a three-decade time series of estuarine fishes and show that the abundances of the individual species fluctuate asynchronously around their mean levels. We then use a time-series modelling approach to examine the consequences of different patterns of turnover, by asking how the correlation between the abundance of a species in a given year and its abundance in the previous year influences the structure of the overall assemblage. Classical diversity measures that ignore species identities reveal that the observed assemblage structure will persist under all but the most extreme conditions. However, metrics that track species identities indicate a narrower set of turnover scenarios under which the predicted assemblage resembles the natural one. Our study suggests that species diversity metrics are insensitive to change and that measures that track species ranks may provide better early warning that an assemblage is being perturbed. It also highlights the need to incorporate temporal turnover in investigations of assemblage structure and function.     

Strategies for mammal conservation under climate change in the Amazon

Climate change is not only a major threat to biodiversity, it is also a big challenge to the development of conservation strategies. Scientists and practitioners need to select or avoid areas at greatest risk for species protection, i.e., acting in a proactive or a reactive manner. This proactive/reactive dichotomy takes a particular formulation under the likely changes in climate. Selecting for low-risk areas (usually referred to as climate refugia) is supposed to protect more species with a greater guarantee of their long-term persistence. As a consequence, populations at greatest risk are left unprotected and probably committed to extinction. On the other hand, managing species in high-risk areas is more expensive than setting aside areas of climate refugia and encompasses a set of uncertainties, which makes highly-threatened species more costly and difficult to save. Here, we combine ecological niche models and metrics of climate change to develop spatial conservation schemes for mammals in the Brazilian Amazon. These schemes efficiently identify networks of high-risk and refugia priority areas within species current and future distributions, while complementing the protection already achieved by the Amazon’s network of protected areas (PAs). We found that, on average, 25% of mammal distribution is already represented in the established network of PAs. Also, 26% of high-risk and 17% of refugia priority areas overlap with indigenous lands. In addition, species distributions were found mostly in high-risk, compared to in refugia priority areas. We highlight that the strategy to be employed does not necessarily should be binary and a mix of both strategies would guarantee the protection of a larger number of species.     

Do human disturbance variables influence more on fish community structure and function than natural variables in the Wei River basin,China?

Quantifying how human disturbance affects biotic communities in the context of other natural and spatial factors is a vital precursor to develop environmental management strategies to effectively conserve and restore ecosystem. This is particularly so for freshwater ecosystems in heavily populated and increasingly disturbed regions such as the Wei River basin in north-west China. In this paper, we employed both species’ abundance and functional metrics (displaying species diversity, habitat, trophic level, tolerance and abundance) to quantify the effect of human disturbance using canonical correspondence analysis. The results showed that spatial, natural and human disturbance variables can explain 40.1% and 33.7% of the total variation in fish abundance without rare species and with all species, respectively. 37.1% and 37.9% variation can be explained in fish metrics without rare species and with all species. Human disturbance variables explained most of the total variations in the four fish matrices. Inclusion or exclusion of rare species will influence the total explained variation from three factors in fish metrics, but little in fish abundance. Rare species will highlight this relationship with human disturbance gradient. For fish metrics, removing rare species will reflect some wrong information for human disturbance gradient. We recommend to include rare species for fish metrics to assess the impact of environment.     

Identifying priority areas for invertebrate conservation using land snails as models

Mollusca is a megadiverse phylum with an estimated number of 70,000–76,000 described species which can inhabit a wide variety of environments. Among them, land snails are a main component of terrestrial ecosystems and they play a pivotal role in ecosystem functioning. They are suffering habitat loss, overexploitation and competition from introduced species, but are regarded as a “non-charismatic” group for conservation purposes. Orthalicoidea is a dominant faunal element in the Neotropics and in Argentina includes 104 species that inhabit a variety of environments. Their abundance, diversity, comprehensive taxonomy and widespread representation in different ecoregions makes this molluscan group an excellent model for biodiversity assessments. The database used here consisted of 985 unique geographic records of 104 species. Species distribution models were generated using the Maximum Entropy method and Zonation v 3.1 was used to evaluate the proposed conservation goals. Three analyses including species distributions, the current protected areas system (PAs) and the Human print layer were carried out. This allowed the identification of priority areas for conservation, the percentage of the species distribution under PAs and analysis of the potential impacts under current land use and in the priority areas detected above. Sixty-one species were modeled, and 59 of them were included in the priority area selection process due to their high area under curve (AUC) scores. Five high priority areas located in the different ecoregions, were identified: 1-dry Chaco, 2-humid Pampas, 3-Southern Andean Yungas, 4-Alto Paraná Atlantic Forests and 5-high Monte. A small percentage of the average distribution range of Orthalicoidean species (3%) was within the current protected areas. Highest-ranked priority areas for land snails are outside the current protected areas system. When human impact is considered, the priority areas are reduced in size and appear as small patches. However, highest priority areas for conservation continue being those detected in the above analyses. Most of the areas detected are used for economic purposes, creating conflicts of interest between the development of human activities and conservation. This study represents one of the first attempts to identify ecoregion level priority areas for a terrestrial invertebrate group. Further analyses, including new predictors and other molluscan taxa, would improve planning the conservation of poorly known invertebrate groups.     

Is the wild rabbit (<Emphasis Type="Italic">Oryctolagus cuniculus</Emphasis>) a threatened species in spain? Sociological constraints in the conservation of species

The Wild rabbit (Oryctolagus cuniculus) is an endemic species of the Iberian Peninsula and is essential for the conservation of endangered predators. Rabbits are also of high importance as a hunting species. From 1988, rabbits suffered the severe effects of rabbit hemorrhagic disease, which caused large declines in most populations. Despite this fact, the National Red Data Lists continued to classify rabbits as a “Least Concern” species. We used available hunting bag data from 1973 to 2002 to model national trends of rabbit abundance and to evaluate the conservation status according to the criteria of the National Red Data List and the World Conservation Union (IUCN). Generalized Additive Models were used as the statistical framework. The rabbit population of Spain suffered a large decline of about 71% between 1973 and 1993. This decline was 49% in the period 1980–1990. Based on both Spanish and World Conservation Union criteria, rabbits should be listed as ‘Vulnerable’, which demands a Conservation Plan Program. We suggest that the lack of concordance between the best available evidence and the conservation status of the species is a consequence of sociological constraints in conservation decisions. Rabbit conservation could face strong opposition from important socio-economic lobby groups (hunters and farmers). As such, governments and researchers may prefer to exclude rabbits from any status category requiring conservation action, despite the evidence of decline. We call for the urgent development of a nation-wide conservation program for rabbits which includes both socioeconomic constraints and the available biological data on population trends.     

Assessing the impact of revegetation and weed control on urban sensitive bird species

Nature in cities is concentrated in urban green spaces, which are key areas for urban biodiversity and also important areas to connect people with nature. To conserve urban biodiversity within these natural refugia, habitat restoration such as weed control and revegetation is often implemented. These actions are expected to benefit biodiversity, although species known to be affected by urbanization may not be interacting with restoration in the ways we anticipate. In this study, we use a case study to explore how urban restoration activities impact different bird species. Birds were grouped into urban sensitivity categories and species abundance, and richness was then calculated using a hierarchical species community model for individual species responses, with “urban class” used as the hierarchical parameter. We highlight variable responses of birds to revegetation and weed control based on their level of urban sensitivity. Revegetation of open grassy areas delivers significant bird conservation outcomes, but the effects of weed control are neutral or in some cases negative. Specifically, the species most reliant on remnant vegetation in cities seem to remain stable or decline in abundance in areas with weed control, which we suspect is the result of a simplification of the understorey. The literature reports mixed benefits of weed control between taxa and between locations. We recommend, in our case study site, that weed control be implemented in concert with replanting of native vegetation to provide the understory structure preferred by urban sensitive birds. Understanding the impacts of revegetation and weed control on different bird species is important information for practitioners to make restoration decisions about the allocation of funds for conservation action. This new knowledge can be used both for threatened species and invasive species management.