High Conservation Priority Research Articles

Fish Community Responses to Human-Induced Stresses in the Lower Mekong Basin

The Mekong River is one of the world’s largest rivers and has an annual captured fish production of about 2.3 million tonnes, equivalent to around 11 billion USD. Although the Mekong provides important ecological and socioeconomic benefits to millions of people, it is facing intensive change due to anthropogenic stressors. Therefore, it is necessary to understand the changes to the spatiotemporal fish communities to inform sustainable fisheries management. Here, we aimed to characterize patterns of the fish communities and identify the ecological status of each fish community using daily catch data from 2007 to 2018 at 25 monitoring sites in the Lower Mekong Basin (LMB). The collected data were classified by a self-organizing map into four main groups. Group 4 represented the lower Vietnam Mekong Delta (VMD), while groups 1, 2, and 3 were subdivided into subgroups 1a (upper LMB), 1b (upper and middle LMB), 2a (Mekong River below the Khone Falls and Sesan River), 2b (Mekong River below the Khone Falls and Sekong, Sesan and Srepok (3S) Rivers), 3a (Floodplain-Tonle Sap and Songkhram) and 3b (upper VMD). Among the 571 species recorded, 119 were identified as indicator species. Based on the abundance and biomass comparison curves, the fish community of 2b was in a healthier condition with a positive W-statistic value while the rest had a negative W-statistic value. The highest species richness and diversity were observed in 3a and 2b, so these subgroups deserve high management and conservation priority. Likewise, 1a should also be considered as a high priority area since it harbors several endangered and long-distant migratory fishes. It was also noticed that the fish communities of groups 3 and 4, located far from the hydropower dams, remained mostly unchanged compared to those of groups 1 and 2, close to the mainstream and tributary dams in the upper LMB and 3S Rivers.

Identifying conservation priority areas for gymnosperm species under climate changes in China

China has a rich flora of gymnosperms. Gymnosperm species dominate and co-dominate more than half of China's forest area, but many of them are threatened and vulnerable to climate changes. This study mapped the geographical distributions of 209 gymnosperm species in China, modeled the niches of 124 gymnosperm species with adequate records of field occurrences using MaxEnt, and predicted their range changes under two dispersal scenarios (no dispersal and unlimited dispersal) and three emission scenarios (Representative concentration pathway [RCP] 2.6, RCP 6.0, RCP 8.5). To inform gymnosperm conservation facing climate change, we proposed a multi-criteria framework to identify conservation priority areas by integrating information on species diversity patterns and potential climate refugia, and detected gymnosperm conservation gaps with reference to the existing conservation networks. Our results indicated that the centers of species richness, threatened species, and endemism of gymnosperms in China were highly consistent in space and were concentrated in the subtropical mountains. By the 2070s, 64 (RCP 2.6)–88 (RCP 8.5) species would lose more than 10% of their currently suitable climatic niche, and 19 (RCP 2.6)–45 (RCP 8.5) species would lose more than 30%. Cathaya argyrophylla (endangered, EN), Pinus bungeana (EN), Pinus koraiensis (vulnerable, VU) and Torreya fargesii (VU) would be most vulnerable to the projected climate changes. Seven high conservation priority regions were identified, and a substantial proportion of the regions were found lack of adequate protection. The primary recommended measures included increasing the size of protected areas to cover more high priority regions and establishing populations in new sites as required ex-situ conservation efforts.

The northern bald ibis Geronticus eremita: history, current status and future perspectives

AbstractThe northern bald ibis Geronticus eremita was once widespread throughout the Middle East, northern Africa, and southern and central Europe. Habitat destruction, persecution and the impacts of pesticides have led to its disappearance from most of its former range. It disappeared from central Europe > 400 years ago, but has persisted as a relict and slowly growing breeding population in Morocco, where c. 700 wild birds of all ages remain. In Algeria, the last confirmed breeding was in 1984; in Turkey the fully wild population disappeared in 1989, but a population remains in semi-wild conditions. In Syria a small population was rediscovered in 2002, only to subsequently decline to functional extinction. Restoration programmes have been initiated independently in several locations, with over 300 free-flying birds resulting from reintroduction projects in Austria, Germany, Spain and Turkey, to restore both sedentary and fully migratory populations. Maintaining current efforts in Morocco remains a high conservation priority.

Development of a New Habitat Mimicking Tool for Assessing Larval Salamanders in Temperate Forest Streams

Small streams are a high priority for conservation and an important target for biomonitoring. Stream salamanders are a useful indicator for biotic integrity of headwater streams; however, assessing stream salamanders is a challenging endeavor and existing methods can cause habitat disturbance or require expensive equipment. Our goal was to develop an artificial habitat that mimics the natural habitat that salamanders prefer, leading to rapid colonization and that also (1) represents a standardized area and (2) is easy to handle for rapid assessment. After developing a new artificial habitat (the Maloney Salamander Hotel), we tested the device in a variety of streams and compared our method with other techniques. After a series of field tests in a variety of streams through multiple seasons, we found that stream salamanders will colonize the apparatus and that this method yielded results similar or superior to other methods. For efficient and relatively simple assessment, our results indicate that three devices, left in streams for 3 d, should provide a reliable assessment of salamander presence. The device is relatively inexpensive, simple to build, easily handled for efficient deployment and collection, and does not harm the salamanders. We hope the development of this device provides a useful innovation for biological consultants, land managers, and researchers interested in assessing salamander presence in streams.

Vascular plant species diversity of Mt. Etna (Sicily): endemicity, insularity and spatial patterns along the altitudinal gradient of the highest active volcano in Europe.

BackgroundAltitudinal variation in vascular plant richness and endemism is crucial for the conservation of biodiversity. Territories featured by a high species richness may have a low number of endemic species, but not necessarily in a coherent pattern. The main aim of our research is to perform an in-depth survey on the distribution patterns of vascular plant species richness and endemism along the elevation gradient of Mt. Etna, the highest active volcano in Europe.MethodsWe used all the available data (literature, herbarium and seed collections), plus hundreds of original (G Giusso, P Minissale, S Sciandrello, pers. obs., 2010–2020) on the occurrence of the Etna plant species. Mt. Etna (highest peak at 3,328 mt a.s.l.) was divided into 33 belts 100 m wide and the species richness of each altitudinal range was calculated as the total number of species per interval. In order to identify areas with high plant conservation priority, 29 narrow endemic species (EE) were investigated through hot spot analysis using the “Optimized Hot Spot Analysis” tool available in the ESRI ArcGIS software package.ResultsOverall against a floristic richness of about 1,055 taxa, 92 taxa are endemic, of which 29 taxa are exclusive (EE) of Mt. Etna, 27 endemic of Sicily (ES) and 35 taxa endemic of Italy (EI). Plant species richness slowly grows up to 1,000 m, then decreases with increasing altitude, while endemic richness shows an increasing percentage incidence along the altitudinal gradient (attributed to the increased isolation of higher elevation). The highest endemic richness is recorded from 2,000 up to 2,800 m a.s.l., while the highest narrow endemic richness (EE) ranges from 2,500 up to 2,800 m a.s.l. Life-form patterns clearly change along altitudinal gradient. In regard to the life-form of the endemics, the most represented are the hemicryptophytes, annual plants (therophytes) are prevailing at lower altitudes and show a decreasing trend with increasing elevation, while chamaephytes are featured by an increasing trend up to 3,100 m of altitude. Furthermore, the results of the hotspot analysis emphasize the high plant conservation priority areas localized in oro-mediterranean (1,800–2,400 m s.l.m.) and cryo-mediterranean (2,400–2,800 m) bioclimatic belts, in correspondence of the oldest substrates of the volcano.ConclusionsHigh plant speciation rate caused by increasing isolation with elevation is the most plausible explanation for the largest active volcano in Europe. The high degree of endemic species on Mt. Etna is linked to its geographical, geological and climatic isolation, all important drivers of speciation acting on the population gene flows. The hot spot map obtained represents a useful support for help environmental decision makers to identify priority areas for plant conservation.

Subregional variation in cover and diversity of hard coral (Scleractinia) in the Western Province, Solomon Islands following an unprecedented global bleaching event.

Coral reefs are critically important marine ecosystems that are threatened worldwide by cumulative impacts of global climate change and local stressors. The Solomon Islands comprise the southwestern boundary of the Coral Triangle, the global center of coral diversity located in the Indo-Pacific, and represent a bright spot of comparatively healthy coral reef ecosystems. However, reports on the status of coral reefs in the Solomon Islands are based on monitoring conducted at 5 stations in 2003–2004 and 2006–2007, with no information on how corals in this region have responded to more recent global bleaching events and other local stressors. In this study, we compare reef condition (substrate composition) and function (taxonomic and morphological diversity of hard corals) among 15 reefs surveyed in the Western Province, Solomon Islands that span a range of local disturbance and conservation histories. Overall, we found high cover of live hard coral (15–64%) and diverse coral assemblages despite an unprecedented 36-month global bleaching event in the three years leading up to our surveys in 2018. However, there was significant variation in coral cover and diversity across the 15 reefs surveyed, suggesting that impacts of global disturbance events are moderated at smaller scales by local anthropogenic factors (fisheries extraction, land-use impacts, marine management) and environmental (hydrodynamics) conditions. Our study provides evidence that relatively healthy reefs persist at some locations in the Solomon Islands and that local stewardship practices have the potential to impact reef condition at subregional scales. As coral reef conservation becomes increasingly urgent in the face of escalating cumulative threats, prioritising sites for management efforts is critical. Based on our findings and the high dependency of Solomon Islanders on coral reef ecosystem services, we advocate that the Western Province, Solomon Islands be considered of high conservation priority.

RECENT LAND USE AND LAND COVER CHANGE DYNAMICS IN THE GRAN CHACO AMERICANO

Abstract. Land transformation is one of the most significant human changes on the Earth’s surface processes. Therefore, land use land cover time series are a key input for environmental monitoring, natural resources management, territorial planning enforcement at national scale. We here capitalize from the MapBiomas initiative to characterize land use land cover (LULC) change in the Gran Chaco between 2010 and 2017. Specifically we sought to a) quantify annual changes in the main LULC classes; b) identify the main LULC transitions and c) relate these transitions to current land use policies. Within the MapBiomas project, Landsat based annual maps depicting natural woody vegetation, natural herbaceous vegetation, dispersed natural vegetation, cropland, pastures, bare areas and water. We used Random Forest machine learning algorithms trained by samples produced by visual interpretation of high resolution images. Annual overall accuracy ranged from 0,73 to 0,74. Our results showed that, between 2010 and 2017, agriculture and pasture lands increased ca. 3.7 Mha while natural forestry decreased by 2.3 Mha. Transitions from forests to agriculture accounted for 1.14% of the overall deforestation while 86% was associated to pastures and natural herbaceous vegetation. In Argentina, forest loss occurred primarily (39%) on areas non considered by the territorial planning Law, followed by medium (33%), high (19%) and low (9%) conservation priority classes. These results illustrate the potential contribution of remote sensing to characterize complex human environmental interactions occurring over extended areas and timeframes.

Low genetic diversity indicating the threatened status of Rhizophora apiculata (Rhizophoraceae) in Malaysia: declined evolution meets habitat destruction

Worldwide, many mangrove species are experiencing significant population declines, including Rhizophora apiculata, which is one of the most widespread and economically important species in tropical Asia. In Malaysia, there has been an alarming decline in R. apiculata populations driven primarily by anthropogenic activities. However, the lack of genetic and demographic information on this species has hampered local efforts to conserve it. To address these gaps, we generated novel genetic information for R. apiculata, based on 1,120 samples collected from 39 natural populations in Peninsular Malaysia. We investigated its genetic diversity and genetic structure with 19 transcriptome and three nuclear microsatellite markers. Our analyses revealed a low genetic diversity (mean He: 0.352) with significant genetic differentiation (FST: 0.315) among populations of R. apiculata. Approximately two-third of the populations showed significant excess of homozygotes, indicating persistent inbreeding which might be due to the decrease in population size or fragmentation. From the cluster analyses, the populations investigated were divided into two distinct clusters, comprising the west and east coasts of Peninsular Malaysia. The western cluster was further divided into two sub-clusters with one of the sub-clusters showing strong admixture pattern that harbours high levels of genetic diversity, thus deserving high priority for conservation.

Identifying high-priority conservation areas for endangered waterbirds using a flagship species in the Korean DMZ

The Hangang River and Imjingang River estuaries in Korea are part of the main transit route for many migratory birds that use the East Asia-Pacific flyway. Despite the global importance of this area as a seasonal bird stopover site and resting area, conservation areas have not been established in this area based on ecological properties. This study aimed to examine the umbrella effect of the white-naped crane (Antigone vipio), which is one of the best-known flagship species in East Asia, and to determine the effectiveness of establishing a conservation plan in the western DMZ based on the distribution of white-naped cranes. Species distribution modeling was performed for the white-naped crane; other threatened waterbirds wintering in the western DMZ; Group 1, including species with ecological traits similar to those of the white-naped crane; and Group 2, including species with ecological traits different from those of the white-naped crane. The modeling was based on field survey data from a citizen science project, and a systematic conservation planning approach was adopted for each species group. The results showed no significant differences between the plan for the target species and the plans for the other species groups, indicating that protecting white-naped cranes habitat can also protect the habitat of other threatened waterbirds.

Felids, forest and farmland: identifying high priority conservation areas in Sumatra

ContextEffective planning for protected areas and wildlife population management requires a firm understanding of the location of the species’ core habitat patches, the dispersal corridors connecting them, and the risk they face from key threats, notably deforestation.ObjectivesTo quantify and map core habitat patches and dispersal corridors for Sunda clouded leopard (Neofelis diardi diardi), Asiatic golden cat (Catopuma temminckii) and marbled cat (Pardofelis marmorata) across the 16,000 km2 tropical rainforest Kerinci Seblat landscape, Sumatra. Also, to model future forest loss and fragmentation and its effect on landscape connectivity for populations of these threatened species.MethodsUsing data from camera trap (671 sites/55,856 trap nights), and occupancy modelling, we developed habitat use maps and converted these into species-specific landscape resistance layers. We applied cumulative resistant kernels to map core areas and we used factorial least-cost paths to define dispersal corridors. A 17-year deforestation dataset was used to predict deforestation risk towards the integrity of corridors and core areas.ResultsThe occupancy estimates of the three cats were similar (0.18–0.29), with preference shown for habitats with dense tree cover, medium elevation and low human disturbance. The overlap between core areas and corridors across the three species was moderate, 7–11% and 10%, respectively. We predicted future loss of 1052 km2 of forest in the landscape, of which 2–4% and 5% in highly importance core areas and corridors.ConclusionsThis study provides a valuable guidance for identifying priority areas in need of urgent protection within and outside the protected area network, and where infrastructure development planning can incorporate wildlife conservation goals.

Twelve Recommendations for Advancing Marine Conservation in European and Contiguous Seas

Like most ocean regions today, the European and contiguous seas experience cumulative impacts from local human activities and global pressures. They are largely in poor environmental condition with deteriorating trends. Despite several success stories, European policies for marine conservation fall short of being effective. Acknowledging the challenges for marine conservation, a 4-year multi-national network, MarCons, supported collaborative marine conservation efforts to bridge the gap between science, management and policy, aiming to contribute in reversing present negative trends. By consolidating a large network of more than 100 scientists from 26 countries, and conducting a series of workshops over 4 years (2016–2020), MarCons analyzed challenges, opportunities and obstacles for advancing marine conservation in the European and contiguous seas. Here, we synthesize the major issues that emerged from this analysis and make 12 key recommendations for policy makers, marine managers, and researchers. To increase the effectiveness of marine conservation planning, we recommend (1) designing coherent networks of marine protected areas (MPAs) in the framework of marine spatial planning (MSP) and applying systematic conservation planning principles, including re-evaluation of existing management zones, (2) designing MPA networks within a broader transboundary planning framework, and (3) implementing integrated land-freshwater-sea approaches. To address inadequate or poorly informed management, we recommend (4) developing and implementing adaptive management plans in all sites of the Natura 2000 European conservation network and revising the Natura 2000 framework, (5) embedding and implementing cumulative effects assessments into a risk management process and making them operational, and (6) promoting actions to reach ‘good environmental status’ in all European waters. To account for global change in conservation planning and management, we further recommend (7) developing conservation strategies to address the impacts of global change, for example identifying climate-change refugia as high priority conservation areas, and (8) incorporating biological invasions in conservation plans and prioritizing management actions to control invasive species. Finally, to improve current practices that may compromise the effectiveness of conservation actions, we recommend (9) reinforcing the collection of high-quality open-access data, (10) improving mechanisms for public participation in MPA planning and management, (11) prioritizing conservation goals in full collaboration with stakeholders, and (12) addressing gender inequality in marine sciences and conservation.

Predicting biodiversity richness in rapidly changing landscapes: climate, low human pressure or protection as salvation?

Rates of biodiversity loss in Southeast Asia are among the highest in the world, and the Indo-Burma and South-Central China Biodiversity Hotspots rank among the world’s most threatened. Developing robust multi-species conservation models is critical for stemming biodiversity loss both here and globally. We used a large and geographically extensive remote-camera survey and multi-scale, multivariate optimization species distribution modelling to investigate the factors driving biodiversity across these two adjoining biodiversity hotspots. Four major findings emerged from the work. (i) We identified clear spatial patterns of species richness, with two main biodiverse centres in the Thai-Malay Peninsula and in the mountainous region of Southwest China. (ii) Carnivores in particular, and large ungulates to a lesser degree, were the strongest indicators of species richness. (iii) Climate had the largest effect on biodiversity, followed by protected status and human footprint. (iv) Gap analysis between the biodiversity model and the current system of protected areas revealed that the majority of areas supporting the highest predicted biodiversity are not protected. Our results highlighted several key locations that should be prioritized for expanding the protected area network to maximize conservation effectiveness. We demonstrated the importance of switching from single-species to multi-species approaches to highlight areas of high priority for biodiversity conservation. In addition, since these areas mostly occur over multiple countries, we also advocate for a paradigmatic focus on transboundary conservation planning.

Vulnerabilidade ambiental em áreas de caatingas na unidade de conservação parna do Catimbau, Pernambuco, semiárido brasileiro

O Parque Nacional do Catimbau é uma unidade de conservação integral muito importante na conservação da biodiversidade do bioma Caatinga. Estando situado na região semiárida de Pernambuco, na zona de transição entre o agreste e sertão, o parque comporta excessiva beleza de caatingas, monumentos esculpidos pela ação erosiva dos ventos em rocha arenítica e diversos sítios arqueológicos. Sabendo-se que o Parna do Catimbau constitui áreas de prioridade alta de conservação devido à susceptibilidade a desertificação, essa pesquisa teve como foco avaliar a vulnerabilidade das caatingas presentes nesta unidade de conservação. A metodologia utilizada contou com a aplicação do índice de vegetação ajustado ao solo (IVAS), sensoriamento remoto termal e visita em campo que permitiu a análise da espacialização das imagens orbitais, dos satélites Landsat 5 e 8 nos anos de 1995, 2006 e 2016. Os resultados mostraram aumento térmico nas áreas de caatingas e impactos ambientais ocasionados pela antropização de suas áreas. A antropização das caatingas no interior do Parna do Catimbau fere a Lei 9.985/00, que institui o Sistema Nacional de Unidades de Conservação (SNUC) e define as atribuições de uma unidade de conservação de uso integral. Sendo necessário para essa UC o alinhamento de sua gestão com o SNUC e a implantação de espaços de aprendizagem para disseminação da educação ambiental à população dos municípios que a integram.

Ex situ and in situ conservation gap analysis of crop wild relative diversity in the Fertile Crescent of the Middle East

Crop wild relatives (CWRs) are important reservoirs of adaptive traits for crop breeding programmes. Both ex situ and in situ conservation approaches should be deployed to ensure CWR availability for use. This paper aims to (a) create a regional database of occurrence records for the 441 priority CWRs in the Fertile Crescent, (b) identify CWR-rich areas in the Fertile Crescent, (c) recommend locations to implement genetic reserves intended for CWRs active in situ conservation and (d) undertake ex situ and in situ conservation gap analyses. The study area comprises Jordan, Syria, Palestine/Israel, Lebanon, Turkey and Iraq. Occurrence records of the 441 priority CWR within the Fertile Crescent were gathered from herbaria, gene banks and online databases. Gaps in the current ex situ and in situ conservation were identified. Hotspots of CWR diversity were identified, and complementary analysis was carried out to identify areas for in situ conservation using DIVA-GIS. Then proposed genetic reserves were compared with the existing protected areas to establish genetic reserve areas whether within or outside the protected areas. A total of 23,878 occurrence records were collated for 441 CWR priorities. The first priority grid square is located in Syria near Tal Kalakh City, close to the Lebanese border from the north. The second priority site is located in Turkey’s Izmir Province near Kemal Atatürk Mahallesi. The third priority site is located in Turkey’s Sahinbey/Gaziantep Province. The ex situ gap analysis revealed that of the 441 taxa, 134 (30%) CWRs are totally absent from the current gene banks collections. Only 307 (70%) CWRs are represented in gene banks, and, of these taxa, 252 (57%) of them have less than 10 accessions in gene banks. A total of 353 taxa were categorised as a high priority for collection and conservation; 23 taxa were categorised as a medium priority and 41 taxa as a low priority. However, 24 taxa were identified that did not require urgent collection (see Supplementary Table 7). The most important areas for a further collection of ex situ conservation are located in the west and south of Turkey across the Mediterranean seashore, north of Lebanon and west of Syria (in Lattakia and Tartus Governorate), across the border between Turkey and Syria and northern Iraq. Ten genetic reserves are recommended in the Fertile Crescent for CWR conservation. The results and methods used will help meet the conservation targets of CWR in the Fertile Crescent; they will also help achieve global food security.

Habitat loss and thermal tolerances influence the sensitivity of resident bird populations to winter weather at regional scales.

Climate change and habitat loss pose the greatest contemporary threats to biodiversity, but their impacts on populations largely vary across species. These differential responses could be caused by complex interactions between landscape and climate change and species-specific sensitivities. Understanding the factors that determine which species are most vulnerable to the synergistic effects of climate change and habitat loss is a high conservation priority. Here, we ask (a) whether and to what extent land cover moderates the impacts of winter weather on population dynamics of wintering birds, and (b) what role species' physiology might play in modifying their responses to changing weather conditions. To address these questions, we used thousands of observations collected by citizen scientists participating in Project FeederWatch to build dynamic occupancy models for 14 species of wintering birds. Populations of wintering birds were more dynamic, having higher rates of local extinction and colonization, in more forested landscapes during extreme cold-presumably enabling them to better track resources. However, urban areas appeared to provide refuge for some species, as demonstrated by increased local colonization during the harshest winter weather. Lastly, we found that species-specific differences in thermal tolerances strongly influenced occupancy dynamics such that species that are less cold-tolerant were more likely to go locally extinct at colder sites and during colder periods throughout winter. Together, our results suggest that species that are less cold-tolerant and populations occupying less forested landscapes are most vulnerable to extreme winter weather.

The effects of temporal continuities of grasslands on the diversity and species composition of plants

AbstractSeminatural grasslands are ecosystems rich in biodiversity. However, their decline has been reported worldwide, and identification of grasslands with high conservation priority is urgently required. Recently, an increasing number of studies have reported that past vegetation history affects current biological communities. To evaluate whether the temporal continuity of grasslands promotes biodiversity, and thus can be an indicator of conservation priority, we studied vascular plant communities in old (160–1000s years) and new (52–70 years after deforestation) grasslands, as well as in forests, of Sugadaira Highland in central Japan. The number of plant species was highest in old grasslands, followed by new grasslands and forests. This pattern was much clearer in the number of grassland‐dependent native and grassland‐dependent endangered species, indicating the role of old grasslands as refugia for those species. The species composition differed between old and new grasslands. New grasslands had species compositions in between those of old grasslands and forests, suggesting that the plant community in new grasslands retains the influence of past forestation for more than 52 years after deforestation. Eleven indicator species were detected in old grasslands, but none in new grasslands, suggesting the uniqueness of the plant community in old grasslands. We conclude that the temporal continuity of grasslands increases plant diversity and can be an indicator of grasslands with high conservation priority.

Using geographic information systems to make transparent and weighted decisions on pit development: incorporation of interactive economic, environmental, and social factors

A geographic information systems platform with an analytical hierarchy process was employed to rank the importance of different economic, environmental, and social factors involved in choosing the location of an open-pit operation within a small county in the province of Ontario, Canada. Weighted environmental (hydraulic conductivity, soil types, slope, and elevation) and social (distance from population zones) overlays were combined and then compared against a map of potential sources of sand and gravel deposits (economic factor) to locate the most ideal location for a pit. This resulted in the delineation of four ideal locations for the operation in the north of the county. Here, permeability values are low and there are no major population centres. The decision-making tool developed here has the ability to adapt to changing social and (or) environmental criteria and could greatly improve transparency in natural resource management decisions. The largest limitation to this decision-making tool is that it treats all water sources as equal. As research continues to identify different ecosystem services (i.e., acid neutralization, low contamination source waters, and high biological diversity) for different types of waterways, a ranking scheme could be added along the lines of high versus low conservation priorities for nonrenewable freshwater lake and river resources.

High conservation priority of range-edge plant populations not matched by habitat protection or research effort

High-latitude countries tend to contain the polar range-edge of many species that are nationally rare but globally common. This can focus national conservation efforts toward range-edge populations, whose conservation needs and value are disputed. Using plants in Canada as a case study, we ask whether national species-conservation rankings prioritize range-edge populations, and whether conservation priority is matched by habitat protection and research effort. We found that >75% of federally protected plants only occur in Canada peripherally, at the northernmost 20% or less of their total range, and that the most imperilled taxa had the smallest percentage of their range in Canada (endangered plants: median = 1.0%). Occurring peripherally in Canada was associated with higher threat even after accounting for range area, potentially because range-edge taxa experienced 85% higher human population densities in their Canadian range than non-peripheral taxa. High conservation priority was not matched by habitat protection, as more imperilled and more peripheral taxa had smaller fractions of their Canadian range in protected areas. Finally, peer-reviewed research on plants at-risk in Canada was low. Only 42% of plants considered at-risk in Canada had been studied in Canada, and only 11% of species with broad distributions outside Canada had been studied in the context of their wider geographic range—information that is critical to establishing their relative conservation value. Our results illustrate that plant conservation in Canada is fundamentally linked to conserving range-edge populations, yet edge populations themselves are understudied, a research gap we must close to improve evidence-based conservation.

Differences in conservation candidate tidal rivers by cross‐taxon analysis in the Japanese temperate zone

Abstract For effective biodiversity conservation, verifying the correspondence of conservation sites among taxa and identifying the environmental characteristics of these sites are essential; however, only a few such studies have been performed in estuaries. The aim of the present study was to verify the surrogacy of estuarine gobies and crabs, to identify tidal rivers of high conservation priority, and to describe their environmental characteristics. Distribution data for gobies and crabs were collected from 158 tidal rivers in the Kyushu region, Japan. Three conservation scenarios were analysed based on the distribution data of gobies alone, of crabs alone, and of both taxa, in order to assess the correspondence of the conservation candidates (i.e. tidal rivers) between taxa. The degree of correspondence was poor for the candidates selected on the basis of the distribution data of gobies or crabs separately. More efficient candidates were selected based on the data for both taxa. The environmental characteristics of tidal rivers with high irreplaceability for conservation differed between the taxa. Tidal rivers forming and maintaining large tidal flats covered with fine sediment might have high irreplaceability for goby conservation, whereas rivers with saltmarshes connected to supratidal and intertidal zones might have high irreplaceability for crab conservation. Tidal rivers with a high priority for conservation were identified by overlapping the candidates for three scenarios. These tidal rivers are not necessarily large, but have steep basins with river mouths that are less exposed to ocean waves. Moreover, the percentage of artificial areas in these rivers was low, suggesting that these rivers have not been exposed to excessive anthropogenic disturbance that leads to loss of estuarine habitat. These results show that gobies and crabs are not surrogates for one another.

Restoration of the shifting mosaic of floodplain forests under a flow regime altered by a dam

A braided gravel-bed river provides essential habitats for various plants and animals. However, human regulation of rivers, such as dams, channelization, and other engineering works, alter flow and sediment regimes, which generally cause the degradation of river and riparian ecosystems. One of the prominent changes prevailing in Japanese rivers is forest expansion over gravel bars, and many native plants and animals that depend on gravel-bar habitat are now endangered. The Satsunai River is typical of rivers experiencing forest expansion, so the Japanese government launched a restoration project in 2012 to partially restore its riparian ecosystems. This is a large-scale experiment developed jointly by an interdisciplinary science team and river managers, who conduct monitoring and evaluation under an adaptive management scheme. The main measure to restore gravel bed habitat was an artificial flood regime, releasing a maximum water volume of 120 m3/s, which was a 2-year return period flood before dam construction. A unique feature of the project is that we considered the role of high-magnitude floods with recurrence intervals greater than 20 years after dam construction. We hypothesize that the artificial floods can be timed seasonally to create sites for regeneration and nesting of riparian species, and the high-magnitude floods contribute to maintaining a shifting mosaic structure of floodplain forest and unvegetated gravel-bar patches. We also used critical non-dimensional shear stress analysis to define “flood-disturbance areas” that can be disturbed under the artificial flow regime created by a dam. Artificial floods have been initiated once a year since 2012 at the end of June, synchronized with the seed dispersal period of Salix arbutifolia, which is endangered and a high conservation priority in the project. Thus far, the idea of setting floodplain-disturbance areas and the strategy of using both artificial and high-magnitude floods to restore a shifting mosaic of floodplain habitat patches is appropriate, as we found successful regeneration of S. arbutifolia and an exponential decay curve of the age distribution of floodplain forest patches. However, the sediment regime regulated by the dam was not addressed in this research, so future monitoring should track changes in river morphology associated with reduced sediment supply caused by the dam.