Concern For Biodiversity Conservation Research Articles

Solving the problem of wildfires in the Pantanal Wetlands

The increasing frequency and severity of wildfires is a matter of concern for biodiversity conservation around the world. Integrated fire management (IFM) can effectively prevent wildfires or reduce damage, decreasing the extent of burned areas and consequently carbon emission. However, funding sources for IFM are scarce. The carbon emission avoided by IFM in an indigenous land in the Brazilian Pantanal equals to 100 million dollars per year in carbon credits. This amount could be used to finance IFM in this area, as well as other conservation initiatives, such as forest restoration. A well-implemented program to pay for prevented carbon emission could substantially reduce the extent of burned areas and solve the problem of wildfires in the Pantanal.

Reviewing Introduction Histories, Pathways, Invasiveness, and Impact of Non-Indigenous Species in Danish Marine Waters

Non-indigenous species (NIS) are of concern for biodiversity conservation and ecosystem functioning. We present an updated list of NIS, including cryptogenic species, from Danish marine waters containing 123 species. Benthic invertebrates (36%) and phytoplankton (28%) dominate the list, but fish (15%) and macroalgae (13%) are also important. The Limfjord in Northern Jutland emerges as a hotspot for the introduction of NIS. Data from multiple sources were included, i.e., the National Monitoring Program (NOVANA), the National Fish Atlas project, the citizen science project Arter.dk, research articles, and annual national reports of the ICES working group ITMO. Forty-six NIS species were subject to expert judging using a modified Harmonia protocol; 19 were found to fulfil the four selected criteria identifying a species as being ‘invasive’. Additionally, 38 species, not yet recorded in Danish waters, were evaluated using the same method, and 31 were found to fulfil the ‘invasive’ criteria. For nine selected species, introduction history, distribution maps, and time-series diagrams are presented. Our data document that the national monitoring efforts should be expanded to record macrozooplankton, coastal fish, and mobile epibenthic species. Furthermore, the national data repository, Arter.dk, should be expanded to enable more detailed documentation of new NIS records.

Species diversity, hotspot congruence, and conservation of North American damselflies (Odonata: Zygoptera)

The rapid extinction of species is of considerable concern for biodiversity conservation. Identifying the drivers of species diversity and hotspots is beneficial for developing conservation strategies. Studies on insects have mainly focused on terrestrial species and rarely on semiaquatic species. Using 135,208 georeferenced occurrence records of 296 damselflies across North America, their species richness and endemism (represented by weighted endemism) patterns were mapped in a 100 × 100-km grid size, and the effects of environmental variables on species richness and endemism were investigated using generalized linear models and hierarchical partitioning. Subsequently, the top 5% grids with species richness and weighted endemism were separately selected as hotspots and their congruence was evaluated. Finally, species diversity hotspots were identified by integrating two types of hotspot grids, and gap analysis was performed to evaluate their conservation status. Temperature conditions and water availability had the strongest influence on species richness and endemism, respectively. Low congruence among species richness and endemism hotspots was observed. Moreover, four species diversity hotspots were identified, namely, region of the eastern United States and southeastern Canada, southwestern United States, central Mexico, and southernmost North America. Approximately 69.31% of the hotspot grids are not a part of the existing protected areas, presenting a significant conservation gap. The habitats of taxonomic groups should be considered while identifying the most common driving mechanisms of endemism. Strengthening the establishment of protected areas in regions with conservation gaps is urgently needed to promote the conservation of damselflies in North America.

Constructing an indices system for evaluating the ecological integrity of forests in western Sichuan, China based on structural equation modeling

With the concern for biodiversity conservation and ecological sustainability, the traditional method of assessing conservation management based on single elements such as timber production, stand structure, and forest area is no longer applicable. Especially for China, where the primary goal of national park conservation management is to “protect and maintain the authenticity and integrity of natural ecosystems”, it is necessary to construct a set of indicators that can comprehensively evaluate the effectiveness of natural ecosystem conservation management. Therefore, in this study, we take Jiuzhaigou and Giant Panda National Park, in Sichuan, China, as examples, and construct a set of ecological integrity evaluation indices system from the perspective of attributes of forest ecosystems. Initially, we screened the candidate indicators based on the coefficient of variation, distribution range, and redundancy analysis and identified 16 indicators as the evaluation indices of ecological integrity. Next, the model fit and the interrelationship of the components of the ecological integrity model were verified using a combination of structural equation modeling and actual data. The model validation results showed that: (1) CMIN/DF = 1.66, RMSEA = 0.058, GFI = 0.954, and other model fit metrics have reached the best reference standard, indicating that the ecological integrity model overall fit is high. (2) In the parameter estimation results of the model observed and latent variables, the ecological integrity model explained 96%, 85% and 89% of the variance in species composition, stand structure and ecological processes, respectively, indicating that the evaluation indices selected can effectively predict the ecological integrity of forests. In addition, we used the factor loadings in the structural equation model to calculate the weights of the indices and used the weighted sum to calculate the ecological integrity. A one-way ANOVA was conducted to compare the differences among the ecological integrity of forests of different origins, forest types and life forms. The relative importance and linear regression were used to elucidate the main factors affecting forest ecological integrity. The results showed that (1) except for the scrub community, the mean value of forest ecological integrity was >0.45, which was in the middle-to-upper level. (2) the ecological integrity of forests of different origins and different forest types showed a changing pattern: natural forest > plantation forest, mixed forest > pure forest. (3) Stand age and elevation strongly influenced the ecological integrity of forests, with relative contribution rates of 64.54% and 11.88%, respectively.

Bryophyte Conservation in Managed Boreal Landscapes: Fourteen-Year Impacts of Partial Cuts on Epixylic Bryophytes

Clear cut harvest simplifies and eliminates old growth forest structure, negatively impacting biodiversity. Partial cut harvest has been hypothesized (1) to have less impact on biodiversity than clear cut harvest, and (2) to encourage old growth forest structures. Long-term studies are required to test this hypothesis as most studies are conducted soon after harvest. Using epixylic bryophytes as indicators, this study addresses this knowledge gap. Fourteen years after harvest, we examined changes in epixylic bryophyte community composition richness and traits, and their microhabitats (coarse woody debris characteristics and microclimate) along an unharvested, partial cuts and clear cuts harvest treatment in 30 permanent plots established in the boreal black spruce (Picea mariana) forests of northwestern Quebec, Canada. Our results were compared to those of an initial post-harvest study (year 5) and to a chronosequence of old growth forests to examine species changes over time and the similarity of bryophyte communities in partial cut and old growth forests. Coarse woody debris (CWD) volume by decay class varied among harvest treatments with partial cuts and clear cuts recording lower volumes of early decay CWD. The epixylic community was richer in partial cuts than in mature unharvested forests and clear cuts. In addition, species richness and overall abundance doubled in partial and clear cuts between years 5 and 14. Species composition also differed among treatments between years 5 and 14. Furthermore, conditions in partial cut stands supported small, drought sensitive, and old growth confined species that are threatened by conditions in clear cut stands. Lastly, over time, species composition in partial cuts became more similar to old growth forests. Partial cuts reduced harvest impacts by continuing to provide favorable microhabitat conditions that support epixylic bryophytes. Also, partial cut harvest has the potential to encourage old growth species assemblages, which has been a major concern for biodiversity conservation in managed forest landscapes. Our findings support the promotion of partial cut harvest as an effective strategy to achieve species and habitat conservation goals.

Effects of Weed Control Practices on Plant Diversity in a Homogenous Olive-Dominated Landscape (South-East of Italy).

Olive groves represent an important economic, agro-ecological, and cultural resource in the Mediterranean Basin. Weed management plays a fundamental role in their sustainable management. The aim of this work was to characterize and assess the plant diversity associated with different weed control practices, in a homogeneous olive-dominated landscape in the South-East of Italy. Sixty-five vegetation plots were sampled in orchards treated with different weed control practices: mowing, tillage, and use of chemical herbicides. The multi-response permutation procedure was used to test the hypothesis of no difference among the treatments. The relationships between plots were visualized by means of non-metric multidimensional scaling ordination. A generalized linear mixed model was used to analyze the relationships between weed control practices and life forms, chorotypes, and diversity indexes. The results showed that the three weed control practices determined slightly different plant communities. Chemically weeded orchards showed an impoverished floristic composition and the lowest diversity, whereas mowing and tillage yielded similar values. These latter two treatments differed for the percentages of hemicryptophytes and therophytes. Moreover, different from other studies, we did not find plant species of particular concern for biodiversity conservation. We hypothesize that this result is due to the monotonous structure of the agro-landscape we investigated, where natural elements are almost lacking. From this point of view, a correct management of agro-districts should consider both the agronomic practices at the level of the individual olive groves and the structure of the agro-landscape.

Human-Wildlife Conflicts in the Southern Yungas: What Role do Raptors Play for Local Settlers?

Simple SummaryHuman-Wildlife conflict (HWC) has become an important threat producing biodiversity loss around the world. As conflictive situations highly depend on their unique socio-ecological context, evaluation of the different aspects of the human dimension of conflicts is crucial to ensure wildlife conservation and people’s well-being at the same time. Raptors have been historically involved in HWC because some of them are considered livestock predators. We conducted interviews to evaluate the existence, extent and characteristics of human-raptor conflicts in the Southern Yungas region in Northwestern Argentina, identified as a priority area for raptor research. Our results suggest that conflict is only concentrated in certain high-profile raptor species—particularly those considered cattle predators—with a general high tolerance towards poultry predators. Livestock and poultry rearing are the only socio-demographic variables associated with the existence of HWC, independently of age, gender and occupation of interviewees. Andean condor, a Vulnerable species persecuted in some regions of Argentina, was the most conflictive species as it is locally considered a livestock predator. Though reports of Condor persecution were scarce in our study, negative attitudes towards this species, together with the increasing number of mass poisonings, highlight the need to address this conflict through true intercultural dialogue and transdisciplinary approaches.Wildlife persecution due to human-wildlife conflict has become a serious concern for biodiversity conservation, especially for many endangered species. In this context, conservation approaches need to consider the socio-ecological dimensions of each particular situation. The aim of this study was to evaluate the existence, extent and social characteristics of Human-Raptor Conflicts (HRC) in the Southern Yungas region in northwestern Argentina. We conducted 115 semi-structured interviews in 21 sites and analyzed attitudes and associations between sociodemographic variables and the existence of HRC. Forty percent of interviewees showed negative attitudes towards raptors, mainly with those species considered livestock predators rather than poultry predators. A total of 11 species were regarded as conflictive because of predation on domestic animals, of which Andean condors showed the highest conflict. The only socio-demographic factor affecting conflicts was livestock and poultry rearing, independently of age, gender and occupation of interviewees. The fact that only 8.7% of interviewees reported taking direct actions towards conflictive species indicates a relatively peaceful coexistence of people with raptors. Nevertheless, negative attitudes towards Andean condor together with their extreme susceptibility to any increase in non-natural mortality indicate the need of an integral conservation approach to tackle future threats for this species’ conservation in the area.

Spatio-temporal remotely sensed indices identify hotspots of biodiversity conservation concern

Over the course of a year, vegetation and temperature have strong phenological and seasonal patterns, respectively, and many species have adapted to these patterns. High inter-annual variability in the phenology of vegetation and in the seasonality of temperature pose a threat for biodiversity. However, areas with high spatial variability likely have higher ecological resilience where inter-annual variability is high, because spatial variability indicates presence of a range of resources, microclimatic refugia, and habitat conditions. The integration of inter-annual and spatial variability is thus important for biodiversity conservation. Areas where spatial variability is low and inter-annual variability is high are likely to limit resilience to disturbance. In contrast, areas of high spatial variability may be high priority candidates for protection. Our goal was to develop spatio-temporal remotely sensed indices to identify hotspots of biodiversity conservation concern. We generated indices that capture the inter-annual and spatial variability of vegetation greenness and land surface temperature and integrated them to identify areas of high, medium, and low biodiversity conservation concern. We applied our method in Argentina (2.8 million km2), a country with a wide range of climates and biomes. To generate the inter-annual variability indices, we analyzed MODIS Enhanced Vegetation Index (EVI) and Land Surface Temperature (LST) time series from 2001 to 2018, fitted curves to obtain annual phenological and seasonal metrics, and calculated their inter-annual variability. To generate the spatial variability indices, we calculated standard deviation image texture of Landsat 8 EVI and LST. When we integrated our inter-annual and spatial variability indices, areas in the northeast and parts of southern Argentina were the hotspots of highest conservation concern. High inter-annual variability poses a threat in these areas, because spatial variability is low. These are areas where management efforts could be valuable. In contrast, areas in the northwest and central-west are where protection should be strongly considered because the high spatial variability may confer resilience to disturbance, due to the variety of conditions and resources within close proximity. We developed remotely sensed indices to identify hotspots of high and low conservation concern at scales relevant to biodiversity conservation, which can be used to target management actions in order to minimize biodiversity loss.

A new protocol for assessing the conservation priority of groundwater‐dependent ecosystems

Abstract Species of conservation concern are usually considered important elements in site prioritization for biodiversity conservation. To overcome the lack of information on species conservation status, multidimensional measures of species rarity can be used as proxies of species vulnerability. Under this assumption, a two‐step protocol for site prioritization of aquatic groundwater‐dependent ecosystems is proposed using invertebrate vulnerability estimated from species' traits. In the first step, each species occurring in the sites of interest are scored according to their vulnerability. In the second step, sites are prioritized using species' scores. Species vulnerability scores are based on five dimensions, for which various traits are scored: (i) geography, (ii) ecology, (iii) biology, (iv) population, and (v) evolutionary history. For each species, the scores of the various traits belonging to the same dimension are multiplied to obtain a synthetic score. These scores are then ranked into four classes and, for each dimension, each species receives a new score that reflects its rank. The sum of these scores represents the species' overall score. Site conservation priorities are assessed by combining species scores into three indices: Sum of Species Scores, Biodiversity Conservation Concern (which relates the sum of species scores with the local species richness) and Groundwater Biodiversity Concern (which is the average of the former two). The protocol is illustrated using case studies in Italy and it is fully implemented in the software AQUALIFE which is freely available at: http://app.aqualifeproject.eu by registered users. Sensitivity analyses showed that the protocol is robust against the lack of information on species biology or sampling limitations. However, trait scoring rests with the user, who must be familiar with the study group. This approach can be applied at any spatial scale and to different types of aquatic groundwater‐dependent ecosystems.

Population status and ecology of the Salmo trutta complex in an Italian river basin under multiple anthropogenic pressures.

Salmonids inhabiting Mediterranean rivers are of particular concern for biodiversity conservation, as they are threatened by various stressors, including habitat alterations, overfishing, climate change, and introgressive hybridization with alien species. In the Tiber River basin (Central Italy), genetic introgression phenomena of the native Salmo cettii with the non‐native Salmo trutta hinder the separate analysis of the two species, which are both included in the S. trutta complex. Little is known about the factors currently limiting the trout populations in this area, particularly with respect to climate change. With the intention of filling this gap, the aims of the current study were to (a) quantify changes in the climate and (b) analyze the distribution, status, and ecology of trout populations, in the context of changing abiotic conditions over the last decades. Fish stock assessments were carried out by electrofishing during three census periods (1998–2004, 2005–2011, and 2012–2018) at 129 sites. The trend over time of meteorological parameters provided evidence for increased air temperature and decreased rainfall. Multivariate analysis of trout densities and environmental data highlighted the close direct correlation of trout abundance with water quality, altitude, and current speed. Climate‐induced effects observed over time in the sites where trout were sampled have not yet led to local extinctions or distribution shifts, indicating a marked resilience of trout, probably due to the buffering effect of intrinsic population dynamics. Decreasing body conditions over time and unbalanced age structures support the hypothesis that variations in hydraulic regime and water temperature could overcome these compensatory effects, which may lead to a severe decline in trout populations in the near future. In a climate change context, habitat availability plays a key role in the distribution of cold‐water species, which often do not have the possibility to move upstream to reach their thermal optimum because of water scarcity in the upper river stretches.

Coherence in Cross-Sectoral Policies is Imperative for Sustainable Management of Ecosystems

Sustainable management of ecosystems is a priority concern for biodiversity conservation and climate change resilience. India has enacted various policies and statutes governing natural resources that form an integral part of ecosystem governance. The federal structure of India's governance confers the power on vertical (three layers of government) and horizontal (various ministries, departments of government) sectors, to legislate on a variety of environmental issues. Under the Constitution of India, subjects related to the protection of the environment, conservation of biological diversity are governed by the Union List; while subjects of water and land are governed by the State List. Subjects concerning forest and wildlife are governed by the Concurrent List of Schedule VII. Implementation of statutes, governing different environmental subjects, is done by various ministries and departments including local self-governments established by 73rd and 74th Constitutional Amendment Act, 1976. Activities defined in the policies are implemented through schemes, plans, programmes or projects. As the ecosystem management is a major sector of biodiversity management, the schemes are divided into core and congruent sectors and related sectoral plans. Nexus approach is used to understand the importance of interlinks in the resource governance of India. This research work is ascertaining that conventional fragmented and isolated approach for governance of natural resources is detrimental to the sustainable management of ecosystems. On the background of climate change and increasing international cooperation for sustainable development, attaining coherence in the cross-sectoral policies governing ecosystem management is imperative.

Microbiota Differences of the Comb Jelly Mnemiopsis leidyi in Native and Invasive Sub-Populations

The translocation of non-indigenous species around the world, especially in marine systems, is a matter of concern for biodiversity conservation and ecosystem functioning. While specific traits are often recognized to influence the success in the establishment of non-indigenous species, the impact of the associated microbial community for the fitness, performance and invasion success of basal marine metazoans remains vastly unknown. In this study, we compared bacterial composition patterns of the invasive ctenophore Mnemiopsis leidyi in different native and invasive sub-populations along with the genetic structure of the host (polymorphic microsatellite markers). Amplicon sequencing of the 16S rRNA gene (V1-V2 hypervariable regions) revealed that M. leidyi as representative of the phylum Ctenophora, the sister group to all metazoans, harbored a distinct microbiota compared to the ambient seawater, which significantly differed across two major tissues, namely epidermis and gastrodermis. Moreover, we identified significant differences in bacterial community compositions between native and invasive sub-populations of M. leidyi indicating, that the microbiota community is likely influenced by the genotypic background of the host.

Conservation of the Threatened Species, Pulsatilla vulgaris Mill. (Pasqueflower), is Aided by Reproductive System and Polyploidy.

Population loss due to habitat disturbance is a major concern in biodiversity conservation. Here we investigate the genetic causes of the demographic decline observed in English populations of Pulsatilla vulgaris and the consequences for conservation. Using 10 nuclear microsatellite markers, we compare genetic variation in wild populations with restored and seed-regenerated populations (674 samples). Emergence of genetic structure and loss of allelic variation in natural populations are not as evident as expected from demographic trends. Restored populations show genetic variation comparable to their source populations and, in general, to the wild ones. Genetic homogeneity is observed in regeneration trials, although some alleles not captured in source populations are detected. We infer that polyploidy, longevity, and clonal reproduction have provided P. vulgaris with the standing genetic variation necessary to make the species resilient to the effects of demographic decline, suggesting that the use of multiple sources for reintroduction may be beneficial to mimic natural gene flow and the availability of multiple allele copies typical of polyploid species.

Updating the national checklist of marine fishes in Spanish waters: An approach to priority hotspots and lessons for conservation

In response to a request from the Spanish Ministry of Farming, Fishing, Food, and Environment (Spanish: Agricultura, Pesca, Alimentación y Medio Ambiente) in 2015, a fish expert group was formed to provide a reference list of marine fish species according to five regions (marine demarcations) established by Spanish Law 41/2010 on the protection of the marine environment. The objective of this article was to update and analyse the data compiled in the marine fish species checklist in order to: 1) provide a complete list of marine fish species in the Spanish Exclusive Economic Zone; 2) compare this checklist between bio-geographical areas; and 3) identify possible priority hotspots for their conservation. We applied several indices, such as the total number of species in each area, species richness, and the Biodiversity Conservation Concern index. We discuss gaps in knowledge and the lessons learned for conservation purposes. A total of 1075 marine fishes were reported in Spanish waters. Most of these fish were well determined, whereas a few were treated as uncertain. The marine demarcation with the most species is the Canary Islands with 795 species, followed by the Spanish north coast demarcation with 506 species. However, the marine demarcations with the most species per area are the Spanish coast of the Gulf of Cádiz and the Strait of Gibraltar-Alboran Sea.

An integrating approach of cellular automata and ecological network to predict the impact of land use change on connectivity

As a primary concern in biodiversity conservation, understanding the impact of land use/cover change (LUCC) on functional connectivity has the overarching significance. Yet, LUCC simulation models used in previous studies are insufficient to tackle the complex and non-linear interactions of land-use components, and thus may not be able to provide the accurate impact assessments. This paper aimed to fill this gap and to find a solution that avoids significant connectivity loss in the future LUCC. The artificial neural network (ANN) based cellular automata (CA) and graph theory were combined, to explore potential changes in functional connectivity under alternative urban expansion scenarios. Results show that, both urban land and forested land will increase in all of future scenarios; however, functional connectivity of each species will still decrease except under a population change based scenario. The increase in forested land and the contrary connectivity loss proved the strong barrier effect caused by urban expansion. The impacts vary by species: small forest mammals might benefit more from the gain in the stepping-stone-like patches, while the intra-patch connectivity loss is the primary threat for large terrestrial mammals. Finally, we identified the key connecting patches (i.e., stepping-stones) and suggested that those patches should be prioritized for protection.

Flow regime shapes seasonal patterns of fish species richness and abundance in main and branch channels of a rice irrigation system

Current modernization of an irrigation system degrades fish habitats in quantity and quality and is a significant concern for biodiversity conservation and management of ecosystem services in rice farming landscapes. Irrigation systems consist of various types of channels, whose hydrological and hydraulic heterogeneities can contribute to the coexistence of diverse fish species in this flooded habitat. We compared seasonal patterns of fish species richness and abundance between main and branch channels which have different functions in an irrigation system with different flow temporality and magnitude: the main channels (mean width 425 cm and mean discharge 0.467 m3/s in irrigation period) and the branch channels (176 cm and 0.115 m3/s, respectively). The branch channels are small and temporary, but densities of fish species richness and abundance were not smaller than the main channels during the irrigation period. Further, clear positive hysteretic loops in species richness and abundance with discharge were found in the branch channels, which indicates that fish species richness and abundance gradually increased with discharge during this hydroperiod. Water velocity strongly constrained species richness and abundance in the main channels but not in the branch channels partially because of slow-flow patches at microhabitat scale with a larger vegetation coverage. We also found that the main channels provided deeper habitats in the non-irrigation period and contributed to maintain fish species richness and abundance. Therefore, managing both the main and branch channels as an indispensable, interconnected channel network can be a key for fish habitat conservation in an irrigation system.

Invasive potential of Eucalyptus globulus and Pinus radiata into native eucalypt forests in Western Australia

Tree plantations are an important cause of plant invasions worldwide, being a serious concern for biodiversity conservation. Pinus and Eucalyptus are the two most important genera for the forestry industry worldwide, with Eucalyptus globulus and Pinus radiata among the most widespread and invasive. In this study we analyse the establishment of wildlings of these two species in native eucalypt forests (karri and jarrah forests) of SW Australia, a global biodiversity hotspot. We selected boundaries between plantations and adjoining native forests (26 for E. globulus and 25 for P. radiata) and established in each a plot 100 m long (aligned to outer edge of forest) × 100 m or 50 m deep into the native forest (for boundaries with P. radiata and E. globulus plantations, respectively), that was thoroughly searched for wildlings.Eucalyptus globulus wildlings were only found in 3 of the 26 boundaries studied, 6 individuals in total, all within first 10 m from the forest edge. Pinus radiata wildlings were found in all boundaries and at all distances inspected. Wildling density was greater in jarrah forest compared to karri forest (mean 70.7 and 24.7 wildlings ha−1; respectively); it was negatively correlated with understorey cover (r = −0.501, F = 7.72, p = 0.011) and the density of older wildlings (20 + years) was positively correlated with time since plantation establishment (r = 0.512; F = 8.16; P = 0.009).Invasion of native eucalypt forests by alien E. globulus does not seem currently of concern in SW Australia. The scheduled short rotations (8–10 years), which means that trees are mostly harvested before reaching their full reproductive potential, lower dispersal ability than P. radiata and the customary establishment of cleared margins around plantations (10 m wide on average) all contribute to reduce the propagule pressure in native forests and with it the invasion potential. Nevertheless, attention should be paid to abandoned plantations left unharvested for longer, which may increase the invasion risks. In contrast, P. radiata plantations do constitute a threat to native vegetation for the invasion capacity of this species, as indicated by the presence of wildlings in all native forests studied, together with the relatively high density of old trees with high reproductive capacity in the forests interior. Awareness about wilding pine spread is urgently needed in SW Australia, in order to minimise the risks.

Similar yet different: co-analysis of the genetic diversity and structure of an invasive nematode parasite and its invasive mammalian host

Animal parasitic nematodes can cause serious diseases and their emergence in new areas can be an issue of major concern for biodiversity conservation and human health. Their ability to adapt to new environments and hosts is likely to be affected by their degree of genetic diversity, with gene flow between distinct populations counteracting genetic drift and increasing effective population size. The raccoon roundworm (Baylisascaris procyonis), a gastrointestinal parasite of the raccoon (Procyon lotor), has increased its global geographic range after being translocated with its host. The raccoon has been introduced multiple times to Germany, but not all its populations are infected with the parasite. While fewer introduced individuals may have led to reduced diversity in the parasite, admixture between different founder populations may have counteracted genetic drift and bottlenecks. Here, we analyse the population genetic structure of the roundworm and its raccoon host at the intersection of distinct raccoon populations infected with B. procyonis. We found evidence for two parasite clusters resulting from independent introductions. Both clusters exhibited an extremely low genetic diversity, suggesting small founding populations subjected to inbreeding and genetic drift with no, or very limited, genetic influx from population admixture. Comparison of the population genetic structures of both host and parasite suggested that the parasite spread to an uninfected raccoon founder population. On the other hand, an almost perfect match between cluster boundaries also suggested that the population genetic structure of B. procyonis has remained stable since its introduction, mirroring that of its raccoon host.

Assessing the risk of invasion of species in the pet trade in Brazil

Biological invasions are a major concern for biodiversity conservation. The release and escape of pet animals are the main sources of mammal invasions. Identifying potential invaders before they are introduced is a key tool for preventing the spread and impact of invasive alien species. Among the tools available for screening potential invaders are risk analysis protocols, which can also be used to assess the risk of species introduced in the past and limit or ban their import or commerce. We aimed to identify potential invasive mammals in the pet trade by applying a risk analysis protocol adapted to Brazil. Six alien mammals sold as pets in Brazil resulted high invasion risk. Rodents resulted the highest risk values. In order to prevent the release of invasive species through the pet trade it is necessary to avoid new introductions based on risk analysis, to identify species pathways, and to combat animal trafficking.

Single‐node vs. multi‐node centrality in landscape graph analysis: key habitat patches and their protection for 20 bird species in NE Spain

Summary Habitat connectivity is a major concern in biodiversity conservation. Network analysis provides efficient tools for assessing landscape connectivity and identifying priority areas for protection. Widespread approaches consist of ranking individual habitat patches by their importance for connectivity. However, depending on the spatial arrangement of patches, and on the complementarity or redundancies between different patches in the network, the group of patches that together best contribute to connectivity may differ from the top individual patches. Here we apply individual ranking (single‐node) and group prioritization (multi‐node) methods to identify key patches in the habitat network of 20 bird species in Catalonia, Spain. We compare single‐node evaluation using the landscape index probability of connectivity (PC) and two multi‐node evaluations that focus on two different aspects of connectivity: reachability and fragmentation. We quantify how well the species’ habitats and key patches are covered by the Natura 2000 network of protected areas, as given by all three methods. We discuss some species‐specific differences between results, and general, multi‐species solutions. The key patches for reachability were widely scattered, while patches that best prevented fragmentation were concentrated in core areas. Key patches according to single‐node PC were in intermediate position, although more similar to the fragmentation patches. The patches that minimized fragmentation were highlighted as more crucial for low‐mobility species, while reachability patches scored higher for long‐distance dispersers. For most species, the key patches were not better protected than total habitat. We identify two main areas that concentrate priority patches for all the studied species (including the endangered Neophron percnopterus) and offer suggestions for the potential improvement of the Natura 2000 network. Our work provides a significant step towards the inclusion of multi‐node prioritization in landscape network analysis. The concept of multi‐node reachability, especially, provides an additional viewpoint to the assessment of connectivity. The multi‐patch algorithm we applied optimizes efficiency, overcoming computational limits associated with the high number of combinations that potentially arise in multi‐node analysis. We believe that a combination of multi‐node evaluations and PC has the potential to increase the realism and applicability of landscape network analysis for biodiversity conservation.