Regional Conservation Planning Research Articles

Conservation-oriented management benefits the Black-faced Spoonbill, an endangered migratory waterbird

Active conservation management is crucial for maintaining and recovering populations of threatened species. Yet, there are remarkably few studies quantifying the benefits of conservation management and comparing ecological and anthropogenic influences on populations. We investigate these issues using the Black-faced Spoonbill Platalea minor as a case study. This species is an endangered migratory waterbird that garnered significant conservation attention along the East Asian-Australasian Flyway. Its global population has shown an upward trend recently, yet the speed of recovery has varied spatially. Understanding the species’ occurrence across wintering sites and the factors driving the geographical variation in recovery is vital for examining the benefits of management. In winter 2021–2022, we surveyed the occurrence and abundance of Black-faced Spoonbills and gathered data on environmental conditions across six important wintering sites in Taiwan and the Chinese mainland. Our results indicated a preference for larger wetlands with water depths of 10–20cm. Birds were more likely to be present in wetlands receiving conservation management interventions. Wetlands with vegetated bunds and fewer artificial materials tended to attract larger flocks. The contribution of wetland size and conservation management aimed at increasing spoonbill abundance varied across regions, with a more significant positive effect of conservation management observed in Taiwan. Our results serve as a valuable reference for regional conservation planning and wetland management in wintering areas, aiding their long-term conservation. In line with this, we recommend increased conservation management efforts informed by our findings, particularly in regions with relatively slow recovery rates.

Landscape influences on thermal sensitivity and predicted spatial variability among brook trout streams in the southeastern USA

AbstractWarming water temperatures as a result of climate change pose a major threat to coldwater organisms. However, the rate of warming is not spatially uniform due to surface‐ground‐water interactions and stream and watershed characteristics. Coldwater habitats that are most resistant to warming serve as thermal refugia and identifying their locations is critical to regional aquatic conservation planning. We quantified the thermal sensitivity of 203 streams providing current and potential habitat for brook trout (Salvelinus fontinalis) across nearly 1000 linear km of their native range in the southern and central Appalachian Mountains region, USA, and characterized their spatial variability with landscape variables available in the National Hydrography Dataset. Using the Bayesian framework, we calculated the maximum slope of the logistic function relating paired weekly mean air temperature and stream temperature as an index of stream thermal sensitivity. Streams differed greatly in thermal sensitivity and those with more resistant water temperature regimes (i.e., thermal refugia) were consistently characterized by southerly latitudes and groundwater input. Landscape variables derived from a principal component analysis explained 16% of the variation in thermal sensitivity, indicating that the existing landscape variables were modestly successful in explaining spatial thermal heterogeneity. Using our model and spatial interpolation, we predicted thermal sensitivity at 8695 stream segments potentially suitable for brook trout in the study region. Thermal refugia were more common southward presumably due to higher elevations, but elsewhere they were also clustered at finer spatial scales. Our analysis informs prioritizing habitat conservation and restoration of this native salmonid and other aquatic organisms that depend on coldwater habitats in a warming world.

Rangewide occupancy of a flagship species, the Coastal California Gnatcatcher (Polioptila californica californica) in southern California: Habitat associations and recovery from wildfire.

The Coastal California Gnatcatcher (Polioptila californica californica), a federally threatened species, is a flagship species for regional conservation planning in southern California (USA). An inhabitant of coastal sage scrub vegetation, the gnatcatcher has declined in response to habitat loss and fragmentation, exacerbated by catastrophic wildfires. We documented the status of gnatcatchers throughout their California range and examined post-fire recovery of gnatcatchers and their habitat. We used GIS to develop a habitat suitability model for Coastal California Gnatcatchers using climate and topography covariates and selected over 700 sampling points in a spatially balanced manner. Bird and vegetation data were collected at each point between March and May in 2015 and 2016. Presence/absence of gnatcatchers was determined during three visits to points, using area searches within 150 x 150 m plots. We used an occupancy framework to generate Percent Area Occupied (PAO) by gnatcatchers, and analyzed PAO as a function of time since fire. At the regional scale in 2016, 23% of the points surveyed were occupied by gnatcatchers, reflecting the effect of massive wildfires in the last 15 years. Similarly, PAO in the post-fire subset of points was 24%, with the highest occupancy in unburned (last fire <2002) habitat. Positive predictors of occupancy included percent cover of California sagebrush (Artemisia californica), California buckwheat (Eriogonom fasciculatum), and sunflowers (Encelia spp., Bahiopsis laciniata), while negative predictors included laurel sumac (Malosma laurina) and total herbaceous cover; in particular, non-native grasses. Our findings indicate that recovery from wildfire may take decades, and provide information to speed up recovery through habitat restoration.

Hydrothermal vent fauna of the western Pacific Ocean: Distribution patterns and biogeographic networks

AbstractAimDeep‐sea hydrothermal vent habitats support a low‐diversity fauna in which most species are unique to the ecosystem. To inform conservation planning around this vulnerable marine ecosystem, we examine species distributions over a wide area to assess the underlying beta‐diversity components and to examine biogeographic patterns. We assess the concept of a highly connected fauna that would repopulate areas of local extinction from distal locations.LocationWestern Pacific Ocean from Japan to New Zealand.MethodsWe assemble a database of 295 confirmed species records for 11 western Pacific vent systems. The SET beta‐diversity framework supports query of the distribution of pairwise pattern components in comparisons among vent systems. We build a network based in graph theory to examine connectivity among vent systems based on shared species similarity. A bipartite network revealed the relative role of each species in linkages among vent system nodes. We assess the importance of sampling bias and distance between systems.ResultsOverall, two‐thirds of the taxa are restricted to a single basin or arc. The Mariana Trough system has the highest corrected weighted endemism for vent‐specific species, followed by that of the Okinawa Trough. Species replacement is the dominant feature of beta‐diversity. Eleven vent systems form seven network modules with stronger connectivity in the Southwest than Northwest Pacific. The Manus Basin vent system emerges as a network ‘hub’ reflecting its central geographic near the equator.Main ConclusionTwo western Pacific biogeographic provinces arise, north and south of the equator that few species transcend. Local and regional conservation plans should consider the low network connectivity and high system endemism in management of hydrothermal vent ecosystems in the event of seabed mining. Species recruitment is unlikely to transcend vent system boundaries. We identify Okinawa Trough, Mariana Trough, Manus Basin, Feni‐Tabar Arc and Kermadec Arc for development of conservation plans that initiate or expand protection.

Dietary flexibility of western red colobus in two protected areas with contrasting anthropogenic pressure

Food distribution and abundance can affect intra- and inter-dietary variation in non-human primates, influencing feeding ecology and altering behaviour. Natural and/or human-induced actions can influence the dynamics between primates and the environment, with associated impacts on socio-ecology and demography. This relationship in anthropogenic landscapes, however, is poorly understood. Here, we use DNA metabarcoding to obtain high resolution dietary diversity data, and multivariate generalised linear models to investigate variation in the diet of this threatened primate. We characterise the diet of the western red colobus (Piliocolobus badius) in both the better preserved Gola Rainforest National Park (GRNP, Sierra Leone), and in the fragmented forests of Cantanhez National Park (CNP, Guinea-Bissau), and evaluate biological, ecological and temporal differences. Dietary plant species richness was high in both protected areas, and the type of plants consumed varied significantly across seasons, space, and time. Although we identify dependence on a few key plants, red colobus in CNP consumed a higher average number of plant taxa than in GRNP, and 11% of the diet consisted of cultivated foods (e.g. mango). This is the first time a molecular approach has been used to investigate red colobus diet, and reveal dietary flexibility in degraded forests. Predicting the consequences of dietary change on long-term population persistence, however, remains a significant knowledge gap. Nevertheless, our results provide critical information to inform targeted regional conservation planning and implementation.

Avian Taxonomic and Functional Diversity in Contrasting Habitats: A Comparative Study of Urban and Remote Forests in Arusha, Tanzania

Urbanisation globally transforms landscapes, impacting biodiversity significantly. In Arusha, Tanzania, rapid urban expansion accentuates the interplay between urbanisation and avian biodiversity. This study investigates urbanisation's influence on avian communities in two contrasting forested habitats: the urban "Themi River Forest" and the remote "Lake Duluti Forest." We explore taxonomic and functional avian diversity, elucidating underlying mechanisms. Taxonomic diversity analysis reveals "Lake Duluti Forest" with slightly higher species richness and "Themi River Forest" with a more even species distribution, reflecting urbanisation's influence. This aligns with global trends indicating reduced urban species richness due to habitat fragmentation. The urban forest, however, demonstrates avian adaptability to urbanised landscapes. Functional diversity analysis uncovers "Lake Duluti Forest" with greater functional richness, indicating a wider array of ecological roles. In contrast, "Themi River Forest" maintains comparable functional evenness, suggesting ecological balance despite urbanisation. Both forests exhibit distinct ecological niches, highlighting avian community flexibility. These findings hold significance for avian conservation and urban planning in Arusha and similar urbanising regions. Higher taxonomic diversity in remote forests underscores conservation importance. The urban forest showcases avian adaptability, emphasising green spaces in urban planning. Long-term conservation should protect both urban and remote forests, integrating strategies for avian habitat preservation and connectivity. This study advances understanding of urbanisation, forest type, and avian biodiversity's intricate relationship, offering insights for effective conservation in evolving urban landscapes

Extending the conservation impact of great ape research: Flagship species sites facilitate biodiversity assessments and land preservation.

To inform regional conservation planning, we assessed mammalian and avian biodiversity in the Djéké Triangle, which is an intact forest with long-term research and tourism focused on western lowland gorillas (Gorilla gorilla gorilla). This critical region serves as a conservation conduit between the Nouabalé-Ndoki National Park (NNNP) in the Republic of Congo and the Dzanga-Ndoki National Park in Central African Republic. Wildlife inventories were conducted to determine if biodiversity in the Djéké Triangle (initially part of a logging concession) was equivalent to the NNNP. Camera traps (CTs) were deployed to estimate species richness, relative abundance, naïve occupancy, and activity patterns of medium-to-large species in mixed species and monodominant Gilbertiodendron forests that comprise the majority of regional terra firma. Species inventories were collected from CTs positioned on a grid and at termite nests throughout the Djéké Triangle and compared to CTs placed in the Goualougo Triangle located within the NNNP. From 10,534 camera days at 65 locations, we identified 34 mammal and 16 bird species. Allaying concerns of wildlife depletion, metrics of species richness in the Djéké Triangle surpassed those of the Goualougo Triangle. Many species were observed to occur across habitats, while others showed habitat specificity, with termite mounds indicated as an important microhabitat feature. Our comparisons of animal activity budgets in different habitat types provide important reference information for other populations and contexts. In conclusion, this study provided empirical evidence of the high conservation value of this region that contributed to increasing the protected status of the Djéké Triangle.

Species-specific ecological traits, phylogeny, and geography underpin vulnerability to population declines for North American birds

Abstract Species declines and extinctions characterize the Anthropocene. Determining species vulnerability to decline, and where and how to mitigate threats, are paramount for effective conservation. We hypothesized that species with shared ecological traits also share threats, and therefore may experience similar population trends. Here, we used a Bayesian modeling framework to test whether phylogeny, geography, and 22 ecological traits predict regional population trends for 380 North American bird species. Groups like blackbirds, warblers, and shorebirds, as well as species occupying Bird Conservation Regions at more extreme latitudes in North America, exhibited negative population trends; whereas groups such as ducks, raptors, and waders, as well as species occupying more inland Bird Conservation Regions, exhibited positive trends. Specifically, we found that in addition to phylogeny and breeding geography, multiple ecological traits contributed to explaining variation in regional population trends for North American birds. Furthermore, we found that regional trends and the relative effects of migration distance, phylogeny, and geography differ between shorebirds, songbirds, and waterbirds. Our work provides evidence that multiple ecological traits correlate with North American bird population trends, but that the individual effects of these ecological traits in predicting population trends often vary between different groups of birds. Moreover, our results reinforce the notion that variation in avian population trends is controlled by more than phylogeny and geography, where closely related species within one region can show unique population trends due to differences in their ecological traits. We recommend that regional conservation plans, i.e. one-size-fits-all plans, be implemented only for bird groups with population trends under strong phylogenetic or geographic controls. We underscore the need to develop species-specific research and management strategies for other groups, like songbirds, that exhibit high variation in their population trends and are influenced by multiple ecological traits.

DNA barcoding reveals threatened and protected elasmobranchs in Tanzanian fish markets

Western Indian Ocean countries have banned elasmobranch finning and enacted legislation to protect endangered elasmobranchs, however finned and morphologically deformed specimens are still landed and traded on Tanzanian fish markets. Such specimens are difficult to identify morphologically, and it is possible that protected elasmobranchs are among these. This study used DNA barcoding to uncover protected elasmobranchs in 102 specimens traded on Tanzanian fish markets. The sampled specimens revealed 23 elasmobranch species, 12 of which (52.1 %) were classified as endangered (EN) or critically endangered (CR) on the IUCN Red List. Three of the identified species (great hammerhead Sphyrna mokarran, oceanic whitetip shark Carcharhinus longimanus, and pelagic thresher Alopias pelagicus) are protected by Tanzanian laws. Hence, it is advised that steps be taken to strengthen law enforcement at landing sites and fish markets in the country. Furthermore, the Third Schedule of Fisheries (Amendment) Regulations of 2009 should be updated to include 11 EN and CR elasmobranchs that are not on the list. Additionally, national and regional elasmobranch conservation plans should be developed to prevent the exploitation of endangered elasmobranchs.

The Effect of Multi-Use Landscapes on Mammal Assemblages and Its Implication for Conservation

It has become clear that state-owned protected areas (PAs) are insufficient in preserving the world’s spatially heterogenous biodiversity. Private land conservation could contribute significantly to national conservation goals, without further burdening state resources. In South Africa, legislation has been introduced to incentivise private landowners to contribute to national biodiversity goals. In this study, we used camera trap arrays and hierarchical multi-species occupancy modelling to evaluate the impact of land-use on mammal (body mass &gt;0.5 kg) diversity in the drylands of South Africa. Four hundred and fifty-one camera traps were deployed across a statutory PA, private PA and a neighbouring group of farmlands, covering ~2096 km2. Although trophic species richness were similar across all three land-uses, occurrence and detection probabilities of larger (&gt;20 kg) species were low in the farmlands and highest in the private PA. In contrast, smaller species had higher occurrence probabilities in the farmlands, where large predators and megaherbivores have been extirpated. Differences in species-specific occurrence probabilities were primarily driven by land-use context, as opposed to fine-scale habitat attributes. These results highlight how a land-use matrix incorporating statutory PAs, private PAs and well-managed rangelands can benefit wildlife conservation, as long as these land-uses are included in carefully developed regional conservation planning.

Long-term response of runoff and sediment load to spatiotemporally varied rainfall in the Lhasa River basin, Tibetan Plateau

Fluvial runoff and sediment play vital roles in channel evolution, material cycling, water resource utilization and ecological environment. In the context of global climate change, the assessment of runoff and sediment in response to climate change is of great significance for water and soil conservation, especially in alpine regions such as the Tibetan Plateau with limited availability of long-term observed data. In this study, based on the available records for the period 1980–2018, the spatiotemporal variations in rainfall-related parameters (rainfall and rainfall erosivity (RE)), and their impacts on the runoff–sediment load (SL) process were investigated in the Lhasa River Basin (LRB) by cross-coherence analysis. In addition, the individual and combined effects of other regional environmental factors (e.g., temperature, snow water equivalent (SWE) and vegetation) on runoff and SL were quantitatively identified using partial least squares structural equation modeling (PLS-SEM). The results showed that the changes in rainfall-related parameters experienced an upward trend at a rate of 3.59 mm/decade (rainfall amount) and 46.05 MJ·mm·ha−1·h−1/decade (RE), respectively. The regions with the most obvious increase occurred in downstream of LRB. However, runoff displayed an insignificant decreasing trend, together with increasing water inputs from the wetter climate in the middle and lower reaches. The contrasting SL trends were found in the middle (significantly descending: 5.5 × 104 t/decade) and downstream reaches (slightly increasing: 19.27 × 104 t/decade). Rainfall-related parameters generally played a positive role in runoff and SL at all hydrological stations, and their action gradually weakened after 2005 despite still being the dominant factor. Other environmental variables, such as vegetation, did not limit runoff but did reduce the SL with an increase in vegetation coverage in the LRB, where large-area vegetation restoration projects were implemented and mainly distributed on the sandy land and floodplain of the lower reach of the basin. Snow, however, had slightly positive promoting effects on runoff and SL under the scenario of SWE reduction with increasing temperature. All above-mentioned variables jointly explained 73.9–76.7% and 39.2–52.4% of the total variability in runoff and SL, respectively. These findings provide valuable insights into future studies on water and soil conservation planning and ecological restoration in cold and high-altitude regions.

Disparate biomes within the Caatinga region are not part of the same evolutionary community: A reply to Araujo et al. (2022)

In recent attempts to estimate plant and bird species diversity in the Caatinga, the largest nucleus of the Seasonally Dry Tropical Forest and Woodland biome in South America, we called into question a widely used delimitation of this region that includes areas of disparate biomes. We argued that the Caatinga is best delimited without rainforest and savanna enclaves that exist in the region, and that such enclaves should be treated as part of those other biomes rather than part of the Caatinga. In a response to our proposal, Araujo et al. (2022) advocated the continued adoption of that broader delimitation. Here we review Araujo et al.’s (2022) criticism and elaborate on this problem. We demonstrate that using a delimitation of the Caatinga that includes areas of disparate biomes precludes measures of biome-specific information, cross-biome comparisons, and large-scale syntheses, and we argue that such a delimitation is a poor framework for both studies of biological phenomena and regional conservation planning.

Drivers of Bird and Rodent Assemblage Composition in Rangelands of Southern Mexican Plateau

Rangelands provide ecosystem services for livestock and habitat for many wildlife species. However, the key features that determine their value for biodiversity conservation need to be assessed regionally. To elucidate the structural attributes that drive bird and rodent assemblages in semiarid rangelands in the southern Mexican Plateau, we studied patches of rangelands dominated by herbaceous plants (open) and xerophytic shrub communities (closed). We hypothesized that different guilds and species of birds and rodents are influenced differently by rangeland condition and different habitat components, and that bird assemblages had a higher turnover rate between patches than rodents. We surveyed the birds and rodents during the three regional climatic seasons and measured ground plant cover of herbs, shrubs, nopales, and trees. Through an information-theoretic approach we tested the effect of range condition and season on all variables of habitat and bird and rodent species richness and abundance. Habitat components (shrubs and nopales) most often included in the best/most parsimonious models explained bird and rodent abundances. Rodent species turnover is lower among rangeland plots of the same type geographically separated than between nearby plots of different type. In contrast, bird species turnover was higher because their higher mobility allows them to explore landscape patches than might offer complementation and/or supplementation. Rangelands in the southern Mexican Plateau should be viewed not only as livestock-producing areas but also as landscape components that can and should be used to effectively support biodiversity conservation, complementing the conservation role of other regional habitats. The high biodiversity conservation potential of the rangelands we studied should be recognized, and both habitat conditions should be incorporated in any regional conservation plans.

Land use effects on phylogenetic and functional diversity of birds: Significance of urban green spaces

Although research has been done in order to understand the impact of urban development on avian diversity, it mainly focused on taxonomic diversity. Here we aimed to assess biodiversity targeting beyond species richness since this has the potential to inform the conservation of healthy functioning ecosystem. We explored how functional and phylogenetic diversity vary between a protected area and urban green spaces. We collected avian data at Lake Chivero Park and six green spaces in the city of Harare, Zimbabwe. The avian point count method at 30 sites for each location (Harare and Lake Chivero Park) was conducted. Alpha diversity indices were compared between Harare and Lake Chivero Park using independent t-test. One-way analysis of variance was applied to test for variation in functional and phylogenetic beta-diversity metrics together with the respective standardized effect size. Urban green spaces had higher species richness, abundance, phylogenetic and functional diversity than Lake Chivero Park. Beta diversity between the two sites was much higher than within sites diversity. The two sites did not differ in terms of beta diversity. Our study shows that urban development that incorporates green spaces maybe critical in the conservation of functional and phylogenetic diversity of avifauna. We suggest that urban landscapes be considered in national and regional conservation plans since they can act as conduits between protected areas, especially for avifauna.

Modeling demersal fish and benthic invertebrate assemblages in support of marine conservation planning.

Marine classification schemes based on abiotic surrogates often inform regional marine conservation planning in lieu of detailed biological data. However, these schemes may poorly represent ecologically relevant biological patterns required for effective design and management strategies. We used a community‐level modeling approach to characterize and delineate representative mesoscale (tens to thousands of kilometers) assemblages of demersal fish and benthic invertebrates in the Northwest Atlantic. Hierarchical clustering of species occurrence data from four regional annual multispecies trawl surveys revealed three to six groupings (predominant assemblage types) in each survey region, broadly associated with geomorphic and oceanographic features. Indicator analyses identified 3–34 emblematic taxa of each assemblage type. Random forest classifications accurately predicted assemblage distributions from environmental covariates (AUC > 0.95) and identified thermal limits (annual minimum and maximum bottom temperatures) as important predictors of distribution in each region. Using forecasted oceanographic conditions for the year 2075 and a regional classification model, we projected assemblage distributions in the southernmost bioregion (Scotian Shelf‐Bay of Fundy) under a high emissions climate scenario (RCP 8.5). Range expansions to the northeast are projected for assemblages associated with warmer and shallower waters of the Western Scotian Shelf over the 21st century as thermal habitat on the relatively cooler Eastern Scotian Shelf becomes more favorable. Community‐level modeling provides a biotic‐informed approach for identifying broadscale ecological structure required for the design and management of ecologically coherent, representative, well‐connected networks of Marine Protected Areas. When combined with oceanographic forecasts, this modeling approach provides a spatial tool for assessing sensitivity and resilience to climate change, which can improve conservation planning, monitoring, and adaptive management.

Sediment yields variation and response to the controlling factors in the Wei River Basin, China

Assessing regional sediment yield variation and their responses to the potential controlling factors are critical to develop specific strategies of soil conservation measures to adapt to future climate change. This study attempted to investigate the spatial–temporal variation of sediment load in the Wei River basin in the midstream of the Yellow River during 1961–2015 at 15 hydrological stations. The results indicated that annual sediment load in the past six decades decreased significantly (P < 0.01) with the changing trends of −6.43 × 104, −3.86 × 104, −4.6 × 104 t/a at Xianyang, Zhangjiashan, and Zhuangtou stations, respectively. Annual sediment load exhibited abrupt changes in the mid-1990s, which were largely attributed to the strong effects of soil conservation measures in the study area. The spatial pattern of soil erosion were characterized by high sediment yield in the north with sparse vegetation cover and well-developed gullies, and low sediment yield in the south with flat plain and good vegetation cover in the Wei River basin. The results of the partial least squares-structural equation model (PLS-SEM) showed that vegetation changes and rainfall variability explained 62.3%, 47.3%, and 40.1% of the variation in runoff at Xianyang, Zhuangtou, and Zhangjiashan stations, respectively, whereas 59.4%, 17.6% and 48% of the variation in sediment load were explained by the combining effects of rainfall variability, changes of vegetation and runoff. This study provides a deep insight for understanding the effects of driving forces on sediment yield changes, and can be useful to regional soil conservation planning in the region.

The response of the suspended sediment load of the headwaters of the Brahmaputra River to climate change: Quantitative attribution to the effects of hydrological, cryospheric and vegetation controls

The response of suspended sediment load to climate change has important implications for downstream ecosystems and biogeochemical cycles. Glaciers, permafrost, vegetation and hydrological processes are rapidly changing in high-altitude regions. However, there is currently no consensus about how and to what extent these factors will affect interannual changes of fluvial sediment export. Here, we investigate the increasing trend of suspended sediment load in the headwaters of the Brahmaputra River from 1972 to 2008. The key influencing factors, including the hydrodynamic flux and erosivity of glacier runoff, precipitation, vegetation cover, and soil erodibility were quantified, and their changing trends were analyzed. Two methods were used to attribute the variation of sediment load; Partial Least Squares Path Modeling (PLS-PM) based on statistical regression and Sediment Identity (SI) based on algebraic equations. The results obtained by these two relatively independent methods were broadly consistent, and the error of the SI model was less than 8%. The sediment load showed a significant increasing trend at an average changing rate of 18.9%/10a, without any abrupt fluctuations. The increase in fluvial sediment load was primarily due to increases in both the amount (43%) and erosivity (55%) of precipitation, combined with minor influences from increased sediment supply due to earlier thawing (16%) and intensified glacier melting (14%). The increases in fluvial sediment load were partially buffered by a decrease in water yield capacity due to denser vegetation cover (−29%). This study provides valuable insights into the natural response of fluvial sediment loads to climatic and environmental change, and the findings are critical for soil and water conservation planning in cold and high-altitude regions.

Projecting the remaining habitat for the western spadefoot (Spea hammondii) in heavily urbanized southern California

Extensive urbanization in coastal southern California has reduced natural habitat in this biodiversity hotspot. To better conserve ecological communities, state and federal agencies, along with local jurisdictions and private stakeholders, developed regional conservation plans for southern California. Although many protected areas exist within this region, the patchwork nature of these protected areas might not provide good coverage for species that require multiple habitat components, such as amphibians with complex life histories. Because of declines in the past century, the status of the western spadefoot ( Spea hammondii ) in southern California is of concern to state and federal wildlife agencies. Species distribution models (SDMs) can aid in determining the conservation status of imperiled species by projecting where suitable habitat remains and how much is protected from further development. We built SDMs that integrated site-occupancy data from systematic pitfall trapping surveys and presence-only data from biodiversity databases and citizen science platforms to project the current distribution of western spadefoots in southern California. Western spadefoot occurrence was positively related to the cover of grassland or shrub/scrub and the % sand in the soil within a 1000 m buffer, and was negatively related to slope, elevation, and distance to ephemeral streams or vernal pools. Most of the remaining unprotected habitat for western spadefoots is in the southern half of its historical range in western San Diego and Riverside counties. A few large tracts of spadefoot habitat exist on U.S. Department of Defense lands and smaller tracts remain on ecological reserves owned by state and local government agencies. Only small patches of habitat remain in the northern half of this clade’s historical range in Ventura, Orange, Los Angeles, and San Bernardino counties. Existing regional conservation plans provide ostensible spatial coverage of the majority of extant habitat for western spadefoots in southern California, but most of the habitat within the jurisdiction of these plans lacks formal protection, exposing this species to further declines as urbanization continues in the 21st century.

Differential patterns of connectivity in Western Pacific hydrothermal vent metapopulations: A comparison of biophysical and genetic models.

Hydrothermal ecosystems face threats from planned deep-seabed mining activities, despite the fact that patterns of realized connectivity among vent-associated populations and communities are still poorly understood. Since populations of vent endemic species depend on larval dispersal to maintain connectivity and resilience to habitat changes, effective conservation strategies for hydrothermal ecosystems should include assessments of metapopulation dynamics. In this study, we combined population genetic methods with biophysical models to assess strength and direction of gene flow within four species of the genus Alviniconcha (A.boucheti, A.kojimai, A.strummeri and A.hessleri) that are ecologically dominant taxa at Western Pacific hydrothermal vents. In contrast to predictions from dispersal models, among-basin migration in A.boucheti occurred predominantly in an eastward direction, while populations within the North Fiji Basin were clearly structured despite the absence of oceanographic barriers. Dispersal models and genetic data were largely in agreement for the other Alviniconcha species, suggesting limited between-basin migration for A.kojimai, lack of genetic structure in A.strummeri within the Lau Basin and restricted gene flow between northern and southern A.hessleri populations in the Mariana back-arc as a result of oceanic current conditions. Our findings show that gene flow patterns in ecologically similar congeneric species can be remarkably different and surprisingly limited depending on environmental and evolutionary contexts. These results are relevant to regional conservation planning and to considerations of similar integrated analyses for any vent metapopulations under threat from seabed mining.

Evaluating InVEST model for estimating soil loss and sediment export in data scarce regions of the Abbay (Upper Blue Nile) Basin: Implications for land managers

This study was aimed to evaluate the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Sediment Delivery Ratio (SDR) model for estimating soil loss and sediment export in data scarce regions of the Abbay (Upper Blue Nile) Basin, Ethiopia with a case study in the Andassa and Koga watersheds. Inputs maps required for InVEST SDR such as rainfall erosivity and soil erodablity factors, Digital Elevation Model (DEM) and land use maps were prepared. Calibration of InVEST SDR was made using the sediment yield data collected at the outlets of the corresponding study watersheds. Model predictions showed different pattern and rates of net soil loss, and sediment export rates in the study watersheds. The result revealed that net soil loss was 58.2 and 27.3 t ha−1 yr−1 for Andassa and Koga watersheds, respectively. The observed sediment yield of Andassa watershed was 19.5 t ha−1 yr−1 while the modeled sediment export with InVEST SDR was 18 t ha−1 yr−1. On the other hand, the observed and simulated sediment yield of Koga watershed was 6 t ha−1 yr−1 and 5.1 t ha−1 yr−1, respectively. The estimated soil loss rates in both watersheds is more than the tolerable soil loss (1–6 t ha−1 yr−1) and soil formation (10–14 t ha−1 yr−1) rates of the study region. The results indicated that InVEST SDR could be used for identifying erosion hotspots and prioritizations of sub-watersheds for soil and water conservation (SWC) planning in data scarce regions of the Upper Blue Nile Basin in particular and the Ethiopian highlands in general.