Potential Habitat Distribution Research Articles

Prediction on the changes in potential suitable areas for mangroves along the coast of Guangxi and the threat from Spartina alterniflora invasion.

As one of the important blue carbon pools in tropical and subtropical intertidal zones, mangroves are widely distributed along the coast of Guangxi in China. To deeply explore the variations of potential suitable habitats for mangroves in China under the background of climate change, based on remote sensing interpretation data of coastal wetlands in Guangxi, global marine environment and bioclimatic environment data in 2021, we constructed a maximum entropy habitat distribution model to simulate the spatial distribution of potential suitable areas for mangroves and the invasive species, Spartina alterniflora, along the coast of Guangxi, and predicted the patterns under extreme climate change scenarios (SSP5-8.5). The results showed that the interpreted area of mangrove forests along the coastline of Guangxi was 9136.7 hm2 in 2021, while the predicted area of potential suitable habitat area was 55955.9 hm2. Current distribution area of mangroves had basically covered its potential high suitability area and nearly 10% of the moderate suitability area. The current area of S. alterniflora was 1320.4 hm2, and the predicted area of potential high suitability area was twice of current area, indicating that there was still a large proportion of high suitability area that was not occupied by S. alterniflora. The most important environmental factors driving the distribution of potential habitats in mangroves were offshore Euclidean distance (62.2%), terrain deviation index (8.7%), average sea surface temperature in the hottest season (6.1%), and seabed terrain elevation (5.6%). The contribution of geographical conditions on mangrove distribution was predominant. Under the climate change scenario (SSP5-8.5), potential suitable area for mangroves would increase by 5.3%, while that for S. alterniflora would decrease by 3.1%. The overlapping proportion of the potential suitable area for mangroves and S. alterniflora was similar under current and SSP5-8.5 scenarios, being 15.2% and 14.5%, respectively. In the future, it is necessary to strengthen the protection and ecological restoration of mangroves along the coast of Guangxi and there is great challenge for preventing further invasion of S. alterniflora.

Climate Change Threatens the Habitat of Pinus massoniana in China

Pinus massoniana Lamb. is one of the main timber tree species. There is a large artificial planting area in South China, and this tree has important economic and ecological value. In this research, we built a comprehensive habitat suitability model based on 115 current data and 22 environmental variables to analyze the potential suitable habitat distribution of this species. Future climate change scenarios were defined as four shared socioeconomic pathways (SSPs): SSP 1–2.6, SSP 2–4.5, SSP 3–7.0, SSP 5–8.5) and four periods (including 2021–2040, 2041–2060, 2061–2080, and 2081–2100) based on nine global circulation model datasets. To fully consider the potential distribution of P. massoniana under specific climate change conditions and soil conditions, we constructed an ensemble model using four commonly used model algorithms. The results indicated that the current suitable habitat for P. massoniana covers approximately 1.10 × 106 km2 in southeastern China. In the future, the model results showed that under different climate change scenarios and at different times, the change in suitable habitat for P. massoniana varied; moreover, under moderate climate change scenarios, the average temperature decreased by less than 3 °C and the suitable habitat area decreased slightly, with an area larger than 0.95 × 106 km2. However, under intense warming scenarios, for which the average temperature increased above 3 °C, the suitable habitat for P. massoniana decreased. In the most severe warming scenario, the suitable habitat area for P. massoniana was reduced to 44% of the base climate conditions with severe habitat fragmentation, which should be fully considered in future planting initiatives and plant protection.

Predicting the Potential Habitat Distribution of Relict Plant Davidia involucrata in China Based on the MaxEnt Model

Davidia involucrata Baill. 1871 (D. involucrata), as a tertiary relict plant unique to China, is a national Class I protected plant with high economic value. Oil extracted from its seeds and peels can be used for both consumption and industrial purposes. It has become a popular income-earning export tree in China because of its graceful posture and beautiful white bracts. Climate change affects the distribution of the species’ potential habitat areas. Thus, studying its natural distribution pattern and future potential habitat distribution changes has great significance for the sustainable resource utilization and biodiversity conservation of D. involucrata. Here, we employed the MaxEnt model and ArcGIS software to predict the current and future (the 2050s and 2070s) potential habitats of D. involucrata via 130 species distribution records and 37 environmental variables. Meanwhile, we used the jackknife method to assess the importance of environmental factors. Our results showed the following: (1) When the RM = 4 and FC = LQHPT, the MaxEnt model exhibited the lowest complexity and overfitting degree while achieving high model prediction accuracy. The area under the curve (AUC) value of the simulated training was 0.958, indicating an excellent forecast. (2) Under the current climate scenario, D. involucrata was mainly concentrated in eastern Sichuan, western Hubei, northern Guizhou, and northwestern Hunan, with an area of 98.02 × 104 km2. (3) The precipitation in the warmest quarter (Bio18, 30%), mean temperature in the driest quarter (Bio9, 24.4%), annual mean radiation (Bio20, 14.6%), and elevation (ele, 12.7%) were the main environmental factors affecting its habitat distribution; the t contribution was 82.1%. (4) Under different future climate scenarios, the potential habitat area of D. involucrata decreased overall. Compared with the current climate scenario, the areas of potential habitats gradually decreased in both the 2050s and 2070s under the ssp126 and ssp585 climate scenarios but decreased in the 2050s and then increased in the 2070s under the ssp370 climate scenario. Therefore, it is of great significance to track and monitor the existing population or community on the basis of the possible changes in its distribution area. Moreover, the artificial breeding of its seedlings should be considered in the future to improve the quality of its germplasm resources. In summary, our findings can provide a scientific understanding of D. involucrata distribution in China and are conducive to conservation and utilization.

Assessing the Current and Future Potential Distribution of Solanum rostratum Dunal in China Using Multisource Remote Sensing Data and Principal Component Analysis

Accurate information concerning the spatial distribution of invasive alien species’ habitats is essential for invasive species prevention and management, and ecological sustainability. Currently, nationwide identification of suitable habitats for the highly destructive and potentially invasive weed, Solanum rostratum Dunal (S. rostratum), poses a series of challenges. Simultaneously, research on potential future invasion areas and likely directions of spread has not received adequate attention. This study, based on species occurrence data and multi-dimensional environmental variables constructed from multi-source remote sensing data, utilized Principal Component Analysis (PCA) in combination with the Maxent model to effectively model the current and future potential habitat distribution of S. rostratum in China, while quantitatively assessing the various factors influencing its distribution. Research findings indicate that the current suitable habitat area of S. rostratum covers 1.3952 million km2, all of which is located in northern China. As the trend of climate warming persists, the potential habitat suitability range of S. rostratum is projected to shift southward and expand in the future; while still predominantly located in northern China, it will have varying degrees of expansion at different time frames. Notably, during the period from 2040 to 2061, under the SSP1-2.6 scenario, the habitat area exhibits the most significant increase, surpassing the current scenario by 19.23%. Furthermore, attribution analysis based on PCA inverse transformation reveals that a combination of soil, climate, spatial, humanistic, and topographic variables collectively influence the suitability of S. rostratum habitats, with soil factors, in particular, playing a dominant role and contributing up to 75.85%. This study identifies target areas for the management and control of S. rostratum, providing valuable insights into factor selection and variable screening methods in species distribution modeling (SDM).

Identifying potential habitats of Himalayan Red Panda Ailurus fulgens (Cuvier, 1825) (Mammalia: Carnivora: Ailuridae) in Neora Valley National Park, West Bengal, India

The Himalayan Red Panda Ailurus fulgens (Cuvier, 1825) is a globally Endangered species whose population is reported to be declining in the wild. It is a priority species for the Neora Valley National Park (NVNP) since it is the flagship species of this ecosystem. Moreover, this landscape functions as an important connecting link of the Himalayan Red Panda habitat between the state of West Bengal and Sikkim. The spatial habitat of the Himalayan Red Panda in this National Park is little known. Our study attempts to identify the spatial distribution of potential habitats for the Himalayan Red Panda using the maximum entropy algorithm (MaxEnt 3.4.1). The model predicted a 55 km2 of potential habitat with the current climate scenario. With climate change, predicted potential habitats are likely to experience significant loss and upward shift to a relatively higher elevation. Hence, the management of the NVNP should identify the potential habitats and accomplish realistic goals to help conserve the Red Pandas.­­

Appraisal of the potential habitat distribution of Madhuca longifolia manifested remarkable resilience under various socio-climatic scenarios pan-India

Appraisal of the potential habitat distribution of Madhuca longifolia manifested remarkable resilience under various socio-climatic scenarios pan-India

Impacts of Climate Changes on Geographic Distribution of Primula filchnerae, an Endangered Herb in China.

Primula filchnerae, an endangered plant endemic to China, has drawn people's attention in recent years due to its ornamental value in flower. It was rarely recorded since being described in 1902, but it was rediscovered in 2009 and is now known from a limited number of sites located in Hubei and Shaanxi Provinces. Since the species is still poorly known, a number of unanswered questions arise related to it: How has P. filchnerae responded to past climate change and how might it respond in the future? Why was P. filchmerae so rarely collected during the past century? We assembled geographic coordinates for P. filchnerae through the field surveys and website searches, and then used a maximum entropy model (MaxEnt) to simulate its potential suitable distribution in six periods with varied carbon emission levels by combining bioclimatic and environmental factors. MaxEnt showed that Min Temperature of the Coldest Month (bio6) and Precipitation of the Coldest Quarter (bio19) affected P. filchnerae's distribution most, with an aggregate contribution >60% and suitable ranges above -5 °C and below 40 mm, respectively. We also analyzed potential habitat distribution in various periods with differing impacts of climate change compared to today's suitable habitats, and in most cases, Shaanxi and Sichuan remained the most stable areas and with possible expansion to the north under various carbon emission scenarios, but the 2050s SSP5-8.5 scenario may be an exception. Moreover, we used MaxEnt to evaluate population shifts, with various scenarios indicating that geometric center would be concentrated in Sichuan Province in China. Finally, conservation strategies are suggested, including the creation of protected areas, long-term monitoring, raising public awareness of plant conservation, situ conservation measures, assisted migration, and species introduction. This study demonstrates how P. filchnerae may have adapted to changes in different periods and provides a scientific basis for germplasm conservation and management.

Simulation and analysis of red-crowned crane habitat suitability using maximum entropy and information entropy models

The red-crowned crane (Grus japonensis) is a rare waterfowl species that is sensitive to environmental changes in its habitat selection; as such it effectively reflects the variation in wetland landscapes. Therefore, analysis of the habitat suitability for the red-crowned crane can be used to determine the species requirements and to predict its potential habitat distribution, thereby providing a basis for the protection of wetlands and endangered species. In this study, the Landsat satellite remote sensing data of Zhalong Wetland from 1996 to 2019 were used to simulate the nest coordinates of red-crowned cranes using a binary logistic model and to simulate the distribution of suitable habitat via a maximum entropy model. Moreover, an information entropy model was used to examine the yearly changes in habitat suitability and the underlying mechanisms and influencing factors. These two entropy models were combined to simulate the habitat suitability distribution and variation with high accuracy, determine the contribution rates of influencing factors, and provide data for analyzing interannual changes. The following results were obtained. First, the habitat suitability was highest in the center, core area and decreased towards the periphery of Zhalong Wetland. Second, the habitat suitability increased in some regions in the south, decreased in some areas in the north, and remained unchanged in the majority of the peripheral regions. Third, habitat suitability was primarily impacted by landscape patterns, distances to rivers and ditches, and vegetation. Red-crowned cranes preferred to reside far from human disturbance in wetlands near rivers with reeds (Phragmites australis) as the dominant species.

Changes in the Potential Habitat Distribution of Typical Fire-Resistant Forest Species under Climate Change in the Subtropical Regions of China

Ecological fire prevention forest belts can effectively alleviate the spread of forest fires and reduce the harm caused by forest fires. Exploring the distribution and changes in suitable growth areas for fire-resistant forest species under the effects of climate change can provide effective references for the introduction of ecological fire prevention and tree species preservation in the region. This study is based on the distribution data of six typical ecological fire prevention forest species in the subtropical regions of China. The maximum entropy model (MaxEnt), optimized by the ENMeval data package, was used to analyze the potential relationship between the ecological environment variables and fire prevention forest species. The potential distribution of certain tree species in the historical period and in future periods is simulated. In addition, the area changes, migration trends, and stable areas of tree species under climate change are also discussed. The research results indicated the following: (1) The AUC values of the optimized model are all higher than 0.9, indicating the optimal prediction results. (2) The climate variables that have the greatest impact on the suitable habitat of Schima superba were the annual mean temperature, precipitation of the driest month, and mean diurnal range. Quercus glauca was mainly influenced by the minimum temperature of the coldest month and the precipitation of the warmest quarter. Castanopsis eyrei was mainly influenced by the precipitation of the driest month and the annual precipitation. The distribution of suitable growth areas for Symplocos sumuntia is mainly influenced by the precipitation of the driest month. The distribution of Camellia oleifera was influenced by the minimum temperature of the coldest month. The potential habitat distribution of Photinia serratifolia was greatly influenced by annual precipitation. (3) Until 2090, the expansion degree of the suitable growth area will be Symplocos sumuntia (51.05%) > Schima superba (19.41%) > Camellia oleifera (10.14%) > Quercus glauca (6.80%) > Castanopsis eyrei (2.34%) > Photinia serratifolia (−6.97%). (4) The centroid of Schima superba will migrate northward. Quercus glauca will migrate northeast. The suitable areas for the migration of Symplocos sumuntia and Castanopsis eyrei will move in a northwest direction, with repeated changes in alum migration, as well as with the largest migration span for Castanopsis eyrei. In addition, Camellia oleifera will move southwest. The centroid of Photinia serratifolia will migrate to the southeast. (5) The six fire-resistant tree species in this study were noted to have excellent stability in Guizhou, Hunan, Jiangxi, Fujian, Guangdong, and Guangxi. This conclusion can provide an effective reference for the introduction of ecological fire prevention tree species and the protection of tree species under climate change in subtropical forest-fire-prone areas in China.

Closing the research-implementation gap: Integrating species and human footprint data into Argentina's forest planning

Closing the research-implementation gap is key for advancing biodiversity conservation. One approach is to generate ecologically relevant spatial datasets that integrate easily with existing management plans. Our goal was to identify priority forest conservation areas in Argentina by combining species distributions, human footprint data, and existing forest zoning. We: (i) mapped potential habitat distributions of 70 plant and animal species associated with forests, and of recognized social and ecological importance, (ii) combined the species distributions with human footprint data to identify priority conservation areas, and (iii) evaluated the juxtaposition of our priority conservation areas with current forest management zones. We found that priority conservation areas (i.e., high number of species and low human footprint) are poorly protected by the current zoning scheme. While the Andean-Patagonian region had a substantial portion (57 %) of priority conservation areas in high protection zones, in four other forest regions we evaluated, only 16–37 % of priority areas had high protection levels. Of great concern are the Chaco and Espinal regions, where 36 % and 39 %, respectively, of priority conservation areas are in low protection zones, where conversion to other uses (row crops, livestock) is allowed. Our results provide new spatial information to managers and conservationists highlighting where current forest zoning performs well, and where it may warrant re-evaluation. Overall, our study highlights the value of integrating species distributions and human footprint maps into existing land use plans to guide conservation efforts in data-poor countries, and is an example of a strategy for closing the research-implementation gap.

Predicting the potential habitat suitability and distribution of “Weed-Onion” (Asphodelus tenuifolius Cavan.) in India under predicted climate change scenarios

Recent shifts in the spectrum of weeds documented throughout the globe in various agroecosystems were purportedly associated with climate change. Consequently, it called for a more thorough investigation of weed vulnerabilities and management in the changing climate scenarios. In the present investigation, we compile geographic occurrence data of an agricultural weed Asphodelus tenuifolius Cavan. using ecospat R package and BIOMOD ensemble forecasting to analyze the existing distribution and anticipate its possible distribution in the future under future climate change scenarios. Nine different algorithms were used and implemented in biomod2 package for modelling the current potential habitat distribution of the selected species across the study region and climatic data was downloaded from WorldClim database. Ensemble modeling showed high habitat suitability of the majority of central, northern, and western Indian regions under current climatic conditions. In addition, by gaining suitable habitats in the future the target species will undergo significant increase in range change. The potential range of habitat suitability for A. tenuifolius is likely to increase from 138.73% to 190.29% in terms of Committee Averaging and 721.42%–1508% in terms of Weighted Mean under Representative Concentration Pathways (RCP 4.5 and RCP 8.5). This ensemble modelling technique will help us to locate the places where its potential range could expand while simultaneously analysing the spatial distributions of field weeds, which may be important for the creation of cutting-edge weed control methods.

Identification of Risk Areas for Gloydius Snakebites in South Korea.

Snakebites can pose a significant threat to human health as the destruction of natural habitats and increased human intrusion into ecosystems result in more frequent encounters with snakes. Mitigation measures for snakebites are particularly crucial for hiking trails where transportation of snakebite victims to medical facilities is challenging due to limited emergency resources and difficult access. This study employed a random forest-based species distribution model approach to investigate the potential habitats of Gloydius spp., specifically Gloydius saxatilis, Gloydius brevicaudus, and Gloydius ussuriensis, in South Korea and to assess the snakebite risk in national parks. Potential habitats of Gloydius spp. were identified and visualized by overlaying binary maps derived from species distribution models (SDMs) of each Gloydius spp. that corresponded to high-risk snakebite areas. In addition, hiking trails with high snakebite risk in the national parks were identified after demonstrating the statistical correlation between the potential habitat distribution of Gloydius spp. and the actual snakebite incidents in major regions of South Korea. The primary environmental variables determining Gloydius spp. habitat were the topographic position index, slope, and the annual average of the maximum and minimum temperatures. The potential habitat of G. saxatilis generally appeared in high-altitude mountainous areas, mostly in the eastern part of the study area. Favorable habitats for G. brevicaudus and G. ussuriensis were predominantly located in mountainous areas throughout the study area, with the exception of some high-altitude mountainous terrain in the east. The number of snakebite incidents per 10,000 people was significantly correlated with the area ratio of Gloydius spp. potential habitat (Spearman's rho = 0.638, p < 0.01). The proportion of snakebite risk areas among national parks in South Korea ranged from 18% to 57%. This study can support practical solutions to prevent injuries and fatalities among hikers due to snakebites by identifying areas with a high risk of snakebite accidents at the hiking-trail level.

Impact of climate change on potential habitat distribution of Sciaenidae in the coastal waters of China

Impact of climate change on potential habitat distribution of Sciaenidae in the coastal waters of China

Habitat selection and population status of breeding Wood Snipe Gallinago nemoricola in an alpine meadow in Sichuan, China

Summary The Wood Snipe Gallinago nemoricola is one of the least known shorebird species, and its habitat associations are very poorly understood. Here we provide the first assessment of the habitat use of the Wood Snipe during the breeding season. Between May and July 2021 at a 4-km2 alpine meadow in Sichuan province, China, we conducted population surveys and behavioural observations to identify sites where breeding Wood Snipe occurred and foraged. We quantified the habitat characteristics and food resource availability of these sites and compared them with randomly selected “background” sites. Comparison between 34 occurrence sites and 25 background sites indicated that during the breeding season, Wood Snipes are not distributed evenly across alpine meadow habitats, but preferred habitats in the lower part (3,378–3,624 m) of the alpine meadow with intermediate levels of soil moisture. In addition, comparison between 17 foraging sites and 24 background sites showed that the Wood Snipe tended to forage at sites with higher soil fauna abundance. We found weak evidence for denser vegetation cover at its height and no evidence for other biotic habitat variables such as vegetation composition or other abiotic habitat variables such as slope, soil penetrability, or disturbance level to influence Wood Snipe habitat associations. Our results suggest that the actual distribution range of the Wood Snipe during the breeding season may be smaller than expected from the extent of apparently suitable habitat. We advise caution in evaluating the potential habitat availability and distribution of the Wood Snipe, and call for further research to better understand the ecology of this rare species to inform its conservation.

Potentially suitable habitat prediction of Pinus massoniana Lamb. in China under climate change using Maxent model

BackgroundPinus massoniana is an important timber species with high ecological and economic value in southern China and a pioneer species for the reforestation of barren mountains. The structure and function of the existing Masson pine ecosystem have been seriously affected by worsening habitats under current climate change. Its suitable habitat is likely to change greatly in the near future.MethodsTo estimate the potential geographic distribution of P. massoniana and its response to climate change, the Maxent model was selected to simulate the potentially suitable habitat and corresponding changes in the distribution pattern of P. massoniana under current and future climate scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5) with two periods (2050s and 2090s).ResultsUnder current climate conditions, the total suitable habitat area of P. massoniana was 2.08 × 106 km2, including 0.76 × 106 km2 of highly suitable habitat, concentrated mainly in Jiangxi and Zhejiang, central and southeastern Hunan, northern Fujian, central and western Chongqing, southern Anhui, central and surrounding areas of Guangdong, central and eastern Guangxi, and northern Taiwan. The areas of moderately suitable habitat and poorly suitable habitat were 0.87 × 106 km2 and 0.45 × 106 km2, respectively. Temperature and precipitation appear to be the most important predictors: precipitation of the driest month (14.7–215.6 mm), minimum temperature of the coldest month (−3.5–13.8°C), annual temperature range (8.1–32.9°C), and mean temperature of the warmest quarter (23.6–34.7°C). P. massoniana are predicted to expand their potential distribution under future climate change: by the end of this century, their total suitable habitat area increased 0.26 × 106 km2 (10.61%) and 0.45 × 106 km2 (17.05%) under the most moderate (SSP1-2.6) and severe (SSP5-8.5) warming scenarios, respectively, by mainly extending northward.ConclusionUnder the different future climate scenarios, the total suitable habitat area of P. massoniana increased by mainly extending northward. Overall, our study clarifies the potential habitat distribution of P. massoniana and provides a critical empirical reference for future P. massoniana conservation and planting practices.

Habitat suitability mapping for a high-value non-timber forest product: A case study of &lt;i&gt;Rauvolfia serpentina&lt;/i&gt;

Non-timber forest products (NTFPs) are essential for rural livelihoods but are often threatened by deforestation and overexploitation. Rauvolfia serpentina is a critical NTFP species; however, there have been no studies on the impact of future climate change on its potential habitat distribution. We used the Maxent modeling approach to address this knowledge gap and determine this species’ current and future suitability under climate change scenarios. The areas more suitable to its occurrence were mainly located near the southwestern coastal regions of Myanmar and India. Based on our predictions, these ‘very high’ suitability areas are likely to decrease in 2070 under both low and high CO2 emission scenarios, indicating the future vulnerability of this species’ habitat to the impact of climate change. This species is a highly valued NTFP species in the study region; therefore, such a reduction in habitat suitability may result in reductions in NTFP production and economic benefits for the dependent populations. Our findings can help define and conserve areas containing the natural habitats of this high-valued NTFP species.

Spatiotemporal Distribution and Main Influencing Factors of Grasshopper Potential Habitats in Two Steppe Types of Inner Mongolia, China

Grasshoppers can greatly interfere with agriculture and husbandry, and they will breed and grow rapidly in suitable habitats. Therefore, it is necessary to extract the distribution of the grasshopper potential habitat (GPH), analyze the spatial-temporal characteristics of the GPH, and detect the different effects of key environmental factors in the meadow and typical steppe. To achieve the goal, this study took the two steppe types of Xilingol (the Inner Mongolia Autonomous Region of China) as the research object and coupled them with the MaxEnt and multisource remote sensing data to establish a model. First, the environmental factors, including meteorological, vegetation, topographic, and soil factors, that affect the developmental stages of grasshoppers were obtained. Secondly, the GPH associated with meadow and typical steppes from 2018 to 2022 were extracted based on the MaxEnt model. Then, the spatial-temporal characteristics of the GPHs were analyzed. Finally, the effects of the habitat factors in two steppe types were explored. The results demonstrated that the most suitable and moderately suitable areas were distributed mainly in the southern part of the meadow steppe and the eastern and southern parts of the typical steppe. Additionally, most areas in the town of Gaorihan, Honggeergaole, Jirengaole, as well as the border of Wulanhalage and Haoretugaole became more suitable for grasshoppers from 2018 to 2022. This paper also found that the soil temperature in the egg stage, the vegetation type, the soil type, and the precipitation amount in the nymph stage were significant factors both in the meadow and typical steppes. The slope and precipitation in the egg stage played more important roles in the typical steppe, whereas the aspect had a greater contribution to the meadow steppe. These findings can provide a methodical guide for grasshopper control and management and for further ensuring the security of agriculture and husbandry.

Spatio-Temporal Variations in the Potential Habitat Distribution of Pacific Sardine (Sardinops sagax) in the Northwest Pacific Ocean

Pacific sardine (Sardinops sagax) is a commercially important species and supports important fisheries in the Northwest Pacific Ocean (NPO). Understanding the habitat distribution patterns of Pacific sardine is of great significance for fishing ground prediction and stock management. In this study, both single-algorithm and ensemble distribution models were established through the Biomod2 package for Pacific sardine by combining the species occurrence data, sea surface temperature (SST), sea surface height (SSH), sea surface salinity (SSS) and chlorophyll-a concentration (Chla) in the NPO during the main fishing season (June–November) from 2015 to 2020. The results indicated that the key environmental variables affecting the habitat distribution of Pacific sardine were the SSH and SST. The suitable habitat area for Pacific sardine showed significant monthly changes: the suitable habitat range in June was larger than that in July and August, while the suitable habitat range gradually increased from September to November. Furthermore, the monthly geometric centers of habitat suitability index (HSI) for Pacific sardine presented a counterclockwise pattern, gradually moving to the northeast from June, and then turning back to the southwest from August. Compared with single-algorithm models, the ensemble model had higher evaluation metric values and better spatial correspondence between habitat prediction and occurrence records data, which indicated that the ensemble model can provide more accurate prediction and is a promising tool for potential habitat forecasting and resource management.

The current and future seasonal geographic distribution of largehead hairtail Trichiurus japonicus in the Beibu Gulf, South China Sea

Largehead hairtail Trichiurus japonicus is a major commercial fish species in the Beibu Gulf of the northwestern South China Sea. Despite much effort to protect the fishery resource, the current stock of T. japonicus is overexploited. As the impacts of climate change unfold globally, seasonal changes in the distribution of largehead hairtail in the Beibu Gulf have not yet been clarified. Maximum entropy model based on mixed layer depth and salinity were projected onto seasonal habitat changes of T. japonicus in the Beibu Gulf under a current scenario and three different Representative Concentration Pathways (126, 370, 585) to evaluate geographic distribution changes under the different climate-change scenarios. The current geographic distribution results showed variation with seasonality, as the wintering population shifts toward the northeast. Under each of three SSP scenarios, there is higher risk to habitat suitability in the 2090s as compared with that in the 2050s. The disadvantage to T. japonicus distribution is greatest in winter under each of the three climate change scenarios, both in the short- and long-term. Potential suitable habitat distributions have a minor range extension in Representative Concentration Pathway 370–2050 winter, but in the rest of the scenes and years they contract to south of the Beibu Gulf. The overall results indicate that seasonal differences in suitable habitat should be considered to ensure effective planning of future management strategies for T. japonicus.

Database records of koalas (Phascolarctos cinereus) in northern Sydney

This study examined records of koalas (Phascolarctos cinereus) in northern Sydney held in online biodiversity databases. There were 221 unique records distributed across the Northern Beaches, Ku-ring-gai, Hornsby and Hills Shire local government areas from 1788 to 2022, with records from the Northern Beaches local government area comprising 68% of this dataset. Records from the 1970s represented 41% of the dataset (90 records), while there were only 42 records from 2000 to 2022. Post-2000 records were spread broadly, showing no major contraction in distribution compared to the spread of earlier records, but with a notable absence of more recent records on the Barrenjoey Peninsula, a previously documented species stronghold. Substantial proportions of records were found in both protected reserves and privately-owned lands, which alludes to the value of the former but also shows that koala conservation in this capital city cannot rely solely on protected reserves. The 2000–22 records were widely distributed across 15 plant community types and areas of non-native vegetation, probably reflecting breeding and dispersal movements more than specific habitat selection. Possibly due to the same influences, none of the 2000–22 records were matched to areas represented by the Koala Habitat Suitability Model, a prediction model for spatial distribution of potential koala habitat across NSW, with a high habitat suitability score (greater than 0.85). We therefore recommend systematic on-ground surveys to clarify the patterns observed from the records.