Evaluation of Bayesian networks for modelling habitat suitability and management of a protected area

To be effective, management of protected areas should be based on the best available evidence, including the scientific literature and expert knowledge. However, lack of such evidence in a suitable form to support decision-making may hinder effective management. Here we examine the use of Bayesian networks to support the management of protected areas, through the development of habitat suitability models for eight species of conservation concern. Bayesian networks were constructed on the basis of the scientific literature and expert knowledge, and were then tested using results from a field survey. Models of all species demonstrated very high discrimination between presence and absence sites, as indicated by AUC values >0.8, with values >0.9 obtained for four species, and Kappa values in the range of 0.4–0.9. The Bayesian networks were then used to examine the impact of different management interventions on habitat suitability of each species, including tree cutting, grazing and burning. Species differed in terms of their sensitivity to different management interventions, and model output provided evidence of both negative and positive interactions between types of intervention. These results highlight the trade-offs that must often be made when undertaking conservation management, and demonstrate the value of Bayesian networks in helping to make such trade-offs explicit. The identification of management impacts through analysis of available evidence also demonstrates the value of Bayesian networks for supporting evidence-based approaches to protected area management.     

Explaining the saproxylic beetle diversity of a protected Mediterranean area

Saproxylic beetle diversity is high at the Cabañeros National Park (central Spain), where woodland habitats exhibit remarkable heterogeneity. Our aim was to explain the diversity of saproxylic beetles, focusing on species turnover among mature woodland types. We surveyed five woodland types that represented the heterogeneity of the park’s woodland habitats. Beetles were collected using window traps over a period of 20 months. The Jaccard Similarity Index was used as indirect value of beta diversity among woodlands and to test the relation between species turnover and geographical distance. We also identified the contribution of species turnover to landscape diversity by using a partitioning model. Moreover, the presence of mixed woodlands (more than one tree species) allowed us to attempt to valorise the effect of tree species (coupled with their historical management) on species turnover among woodlands. Finally, we looked for different saproxylic beetle preferences for habitat and tree species using an indicator value method. We found that saproxylic beetle species composition varied significantly among the studied woodlands. The variation in species turnover was independent from the distance among woodlands, which suggested that beetle dispersal abilities could not explain this high turnover. Tree species within woodlands were a key factor that increased diversity turnover in woodlands and, consequently, the diversity of the park. Moreover, we found saproxylic beetle species that had different habitat and tree species preferences. We conclude that woodland heterogeneity (highly affected by woodland composition) seems to be the driving force for saproxylic beetle diversity in this protected area.     

Benthic habitat and fish assemblage structure from shallow to mesophotic depths in a storm-impacted marine protected area

Coral Reefs - Baseline ecological studies of mesophotic coral ecosystems are lacking in the equatorial Indo-West Pacific region where coral reefs are highly threatened by anthropogenic and...     

论保护区的管理体制

一个国家保护区管理体制是否合理和完善与该国保护区发展的速度和管理的有效程度有密切关系。世界各国保护区的管理体制很不相同,各有长处和不足。本文对保护区的主管部门和管理系统、管理现况、存在问题和发展趋势以及我国保护区管理体制的改革等作一些粗略的评论,期待引起有关方面的关注并进一步开展研究。     

Stable isotopes and trophic positions of littoral fishes from a Mediterranean marine protected area

Stable isotope analyses were employed to explore feeding and foraging habitats and trophic levels of littoral fishes in a western Mediterranean Marine Protected Area (Egadi Islands, Sicily, Italy). Carbon and nitrogen stable isotope ratios were measured in primary producers, invertebrates and fishes collected in December 2001 and January 2002. Fishes of the littoral region of the Egadi Islands had isotopic signatures that fell into a wider range for δ ¹³C (about 6‰) than for δ ¹⁵N (about 3‰). Carbon isotope ratios were consistent with a food web based on mixed sources and two trophic pathways leading to different fish species. Differences in the isotopic composition between islands were higher for benthivorous than for planktivorous fishes. The overall picture gained from this study is of a isotopic distinction between planktivorous and benthivorous fishes, resource partitioning facilitating the coexistence of similar species within the same ecosystem, and spatial variability in the isotopic signatures and trophic level of fishes. Asymmetrical analysis of variance showed that estimated trophic levels were lower in the area with the highest level of protection (Zone A) for only two out of the nine fishes analysed. As a consequence, overall spatial differences do not seem to be a consequence of protection, since in most cases trophic levels did not change significantly between zone A and zones C where professional fishing (trawling apart) is permitted, but of natural sources of variation (e.g. variability in food availability and site-specific food preferences of fishes). However, the results of this study suggest a different response at the species compared to the community level.     

Ecological succession and habitat attributes affect the postfire response of a Mediterranean reptile community

Wildfires are recognized as natural disturbances that have shaped landscape structure and ecosystem composition in many regions of the world. As ectotherms, many Mediterranean reptiles are expected to benefit from the thermal quality of open areas created by fires. However, not all the reptile species respond positively to this pattern. We have explored the response to fire of a Mediterranean reptile community in a protected area of the northeastern Iberian Peninsula. We visually searched for reptiles at 102 sites, including unburnt, recently burnt (2003), and old burnt (1985–1986) localities. The number of reptiles and species richness was higher at burnt sites, and both were related to several variables of the habitat structure. Accordingly, between the two most common species in recently burnt sites, Podarcis hispanica declined in old fire habitats whereas Psammodromus algirus did not. Snakes did not differ between burnt and unburnt areas, although the ambush predator viper Vipera latastei was found more frequently in unburnt habitats. Our results imply that there are different succession trajectories for Mediterranean reptile species according to their habitat preferences, life history traits, and dietary specialization. The study area has been drastically human-altered in the last 100 years by agriculture, pine reforestation, agricultural abandonment, and wildfires. These land use changes drastically alter the vegetation cover, favoring some reptiles and damaging others, and finally can promote local extinctions of sensitive species to habitat shifts.     

The role of protected area zoning in invasive plant management

As anthropogenic pressure on the landscape increases, invasive alien species (IAS) pose a growing threat to areas designed to protect high biodiversity habitats. In order to assess the present danger of IAS spread, we examined 23 Czech sites of community importance (SCI) within Natura 2000 protected areas (PA) over 2015 and mapped the occurrence of four IAS: Solidago spp. (goldenrod), Impatiens glandulifera (Himalayan balsam), Heracleum mantegazzianum (giant hogweed) and Fallopia spp. (Japanese knotweed). The model areas were divided into five monitoring zones, graded by conservation importance and habitat disturbance level (core area [A], broader core area [B], semi-natural habitat [C], anthropogenically affected habitat [D], anthropogenically degraded habitat [E]). Despite a high number of IAS occurrences (3222 localities), habitats of European importance (zone A) showed a relatively low level of invasion (< 0.3% total area). Highest IAS occurrence number was in SCI border areas and disturbed habitats (zones C and E). There was a significant positive correlation between level of invasion inside and outside SCIs, related to human activities such as logging and urbanisation. A strong effect for watercourse vicinity was noted for the occurrence of I. glandulifera and Fallopia spp.; but not for H. mantegazzianum and Solidago spp. A stratified management approach, employing zones delimitation to assess what threat pose IAS to the PA objects of conservation, can be useful to prioritize control measures in IAS local action plans.     

Responses of plant community mycorrhization to anthropogenic influence depend on the habitat and mycorrhizal type

Anthropogenic impact represents a major pressure on ecosystems, yet little is known about how it affects symbiotic relationships, such as mycorrhizal symbiosis, which plays a crucial role in ecosystem functioning. We analyzed the effects of three human impact types – increasing urbanity, introduction of alien plant species (alienness) and modifications in plant species distribution ranges (as a proxy for naturalness) – on plant community overall mycorrhization (including arbuscular, ecto‐, ericoid and orchid mycorrhizal plants) and arbuscular mycorrhization (indicating the degree of forming mycorrhizal symbiosis at plant community level using the relative abundance of mycorrhizal and arbuscular mycorrhizal plants, respectively). The study was carried out in three habitat types, each dominated by a distinct mycorrhizal type – ectomycorrhizal woodlands, ericoid mycorrhizal heathlands and arbuscular mycorrhizal grasslands – at the regional scale in the Netherlands. The response of community mycorrhization and arbuscular mycorrhization to anthropogenic influence showed contrasting patterns, depending on the specific aspect of human impact. Community mycorrhization responded negatively to urbanity and positively to increasing alienness, while arbuscular mycorrhization showed the reverse trend. More natural heathlands were found to be more mycorrhizal and less arbuscular mycorrhizal. The strongest responses were detected in woodlands and heathlands, while mycorrhization in grasslands was relatively insensitive to human impact. Our study highlights the importance of considering mycorrhizal symbiosis in understanding and quantifying the effects of anthropogenic influence on plant communities, especially in woodlands and heathlands.     

Spearfishing regulation benefits artisanal fisheries: the ReGS indicator and its application to a multiple-use Mediterranean marine protected area

The development of fishing efficiency coupled with an increase of fishing effort led to the overexploitation of numerous natural marine resources. In addition to this commercial pressure, the impact of recreational activities on fish assemblages remains barely known. Here we examined the impact of spearfishing limitation on resources in a marine protected area (MPA) and the benefit it provides for the local artisanal fishery through the use of a novel indicator. We analysed trends in the fish assemblage composition using artisanal fisheries data collected in the Bonifacio Strait Natural Reserve (BSNR), a Mediterranean MPA where the spearfishing activity has been forbidden over 15% of its area. Fish species were pooled into three response groups according to their target level by spearfishing. We developed the new flexible ReGS indicator reflecting shifts in species assemblages according to the relative abundance of each response group facing external pressure. The catch per unit effort (CPUE) increased by ca. 60% in the BSNR between 2000 and 2007, while the MPA was established in 1999. The gain of CPUE strongly depended on the considered response group: for the highly targeted group, the CPUE doubled while the CPUE of the untargeted group increased by only 15.5%. The ReGS value significantly increased from 0.31 to 0.45 (on a scale between 0 and 1) in the general perimeter of this MPA while it has reached a threshold of 0.43, considered as a reference point, in the area protected from spearfishing since 1982. Our results demonstrated that limiting recreational fishing by appropriate zoning in multiple-use MPAs represents a real benefit for artisanal fisheries. More generally we showed how our new indicator may reveal a wide range of impacts on coastal ecosystems such as global change or habitat degradation.     

Distribution and feeding habitat characterization of whale sharks Rhincodon typus in a protected area in the north Caribbean Sea

The relationship between the distribution of the whale shark Rhincodon typus and hydrobiological variables in the Caribbean Sea during 2005–2009 was analysed. Monthly trips were made to the R. typus aggregation area during the months when this species is present in the region (May to September) to record sightings and hydrological data and to collect samples to determine nutrients, chlorophyll a (Chl a) and zooplankton biomass. A total of 2104 R. typus were counted and three zones of high abundance were identified: Cabo‐Catoche, Contoy (both within the Whale Shark Biosphere Reserve, WSBR) and the zone knows as Afuera. The zones of greatest R. typus density within the WSBR were characterized by high Chl a concentrations (median: 1·1 mg m^?3, interpercentile range: 0·5–1·8 mg m^?3) and high nutrient concentrations, such as ammonium (median: 2·5 µmol l^?1, interpercentile range: 0·5–6·4 µmol l^?1), due to the influence of local upwelling. A generalized additive model (GAM) was used to explore the relationship between R. typus distribution and the environmental variables inside WSBR. Zooplankton biomass was the most influential environmental variable, supporting the close relationship between R. typus distribution and biological productivity. Copepods were the dominant zooplankton group within the WSBR. In the Afuera zone, there were large R. typus aggregations (>80 individuals) associated with zooplankton dominated by fish eggs and significantly higher mean ± s.d. biomass (3356·1 ± 1960·8 mg m^?3) compared with that recorded inside the WSBR (103·5 ± 57·2 mg m^?3). The differences among zones generated changes in R. typus distribution patterns and provided opportunities to develop local management strategies for this species.     

三峡库区消落带狗牙根种群对水陆生境变化的响应

基于定位观测,研究了三峡水库消落带不同海拔区段狗牙根的种群密度、形态性状和生物量及其分配,结果表明:在3个海拔区段,狗牙根种群密度的大小为浅水位区段(海拔165 ～170 m)＞未经水淹区段(海拔＞172 m)＞深水位区段(海拔145～150m);根径和根系长度的大小为深水位区段＞浅水位区段＞未经水淹区段;种群总生物量和根、茎、叶生物量及茎生物量分配比率为浅水位区段＞未经水淹区段和深水位区段,根、叶生物量分配比率和地下/地上生物量的变化为深水位区段＞浅水位区段和未经水淹区段,浅水位区段的狗牙根种群应对水陆生境变化特有的适应策略是加速伸长生长,增加茎生物量分配;深水位区段的策略是增加分枝节间数量、分枝数量和叶生物量分配;二者共有的适应策略是加速根系生长、增加分蘖数量和地下生物量分配,为在陆地环境中的快速生长提供营养和能量储备.     

Pollinosis related to Zygophyllum fabago in a Mediterranean area

Zygophyllum fabago is a herbaceous plant withairborne pollen found widely in the MurciaRegion, in the Southeast of Spain. Although itsallergenicity has been recently reported,little is known of its involvement inpollinosis. Aerobiological study andsensitization in pollinotics weremeasured using a Hirst volumetric trap. Wehave measured the atmospheric concentrationsof this pollen and other allergenicpollen types in our region, between March 1993 andMarch 1997. Z. fabago pollen wascollected for a morphometric study of thepollen grain, and a lyophilized extract wasprepared for skin prick tests. We haveconducted skin tests with different pollen typesfrom our region and with Z. fabago in1736 patients with symptomssuggesting pollinosis. The size of the pollengrain averages 15.17 × 17.35 µm. Thepollination period extends from May to August,with a mean accumulated concentration of 448grains/m³. Out of 1736 pollinotics,263 (15.15%) showed a positive skin test forZ. fabago, 6 were monosensitized and 257were sensitized to other common pollen types fromour Region. Specific IgE to Z. fabago wasequal or higher than 0.35 ku/l in 86.56% ofsensitized patients. Chenopodiaceae pollinateduring spring and autumn and sensitize a largernumber of patients; Urticaceae reach thehighest pollen concentrations for a longerperiod but are not the primary cause ofpollinosis. This study shows that Z. fabagopollen becomes airborne, elicits an IgEresponse and, like other pollens, contributestowards triggering allergic symptoms.It should therefore be considered arelevant allergen and accordingly beincluded in skin test procedures.     

A marine protected area network does not confer community structure resilience to a marine heatwave across coastal ecosystems

Marine protected areas (MPAs) have gained attention as a conservation tool for enhancing ecosystem resilience to climate change. However, empirical evidence explicitly linking MPAs to enhanced ecological resilience is limited and mixed. To better understand whether MPAs can buffer climate impacts, we tested the resistance and recovery of marine communities to the 2014–2016 Northeast Pacific heatwave in the largest scientifically designed MPA network in the world off the coast of California, United States. The network consists of 124 MPAs (48 no-take state marine reserves, and 76 partial-take or special regulation conservation areas) implemented at different times, with full implementation completed in 2012. We compared fish, benthic invertebrate, and macroalgal community structure inside and outside of 13 no-take MPAs across rocky intertidal, kelp forest, shallow reef, and deep reef nearshore habitats in California's Central Coast region from 2007 to 2020. We also explored whether MPA features, including age, size, depth, proportion rock, historic fishing pressure, habitat diversity and richness, connectivity, and fish biomass response ratios (proxy for ecological performance), conferred climate resilience for kelp forest and rocky intertidal habitats spanning 28 MPAs across the full network. Ecological communities dramatically shifted due to the marine heatwave across all four nearshore habitats, and MPAs did not facilitate habitat-wide resistance or recovery. Only in protected rocky intertidal habitats did community structure significantly resist marine heatwave impacts. Community shifts were associated with a pronounced decline in the relative proportion of cold water species and an increase in warm water species. MPA features did not explain resistance or recovery to the marine heatwave. Collectively, our findings suggest that MPAs have limited ability to mitigate the impacts of marine heatwaves on community structure. Given that mechanisms of resilience to climate perturbations are complex, there is a clear need to expand assessments of ecosystem-wide consequences resulting from acute climate-driven perturbations, and the potential role of regulatory protection in mitigating community structure changes.     

Patterns and drivers of wild bee community assembly in a Mediterranean IUCN important plant area

Recent reports of pollinator declines have stirred interest in investigating the impacts of habitat exploitation on the conservation of pollinator and plant communities. An important prerequisite to tailor conservation action is to understand the drivers and patterns of species-rich communities, and how they change in space and time during a whole season. To account for this, we surveyed wild bees and flowering plants using standardized transects in 11 natural habitat fragments of an IUCN important plant area along the coast of Israel. We used phylogeny- and taxon-based methods of community structure analyses to study the assembly processes of bee communities, and investigated the effects of several landscape parameters on bee diversity using generalized linear models (GLMs). Our results illustrate that natural habitat sites comprised significantly higher species richness compared to disturbed habitat sites, and show that even the smallest habitat fragments harbored unique bee assemblages, with significant species replacement (turnover) found in both space and time. Our GLMs indicated that flower diversity, and semi-natural habitat within 500 m of habitat fragments were important drivers of bee diversity, but we found no evidence for a species—area relationship among sites. Finally, we document a case of phylogenetic overdispersion despite low species richness, which highlights the importance of accounting for phylogenetic diversity rather than only species richness to reach a more fine-grained understanding of pollinator diversity. This, in turn, is pivotal to developing conservation actions to protect these essential pollinators and their interaction with rare and endemic plant species in this highly threatened ecosystem.