Prediction of Historical, Current, and Future Configuration of Tibetan Medicinal Herb Gymnadenia orchidis Based on the Optimized MaxEnt in the Qinghai-Tibet Plateau

The influence of climate change on Primula Sect. Crystallophlomis in southwest China

PURPOSE

Climate change significantly affects the distribution of high-altitude plant species, particularly within the Primula Sect. Crystallophlomis found in Southwest China. This clade is valued for its ornamental and medicinal properties. This study aims to evaluate the impact of climate change on the potential distribution of P. crystallophlomis to inform conservation and ecological research.

METHODS

An optimized Maximum Entropy model (MaxEnt) was utilized to predict the suitable habitat areas of P. crystallophlomis under 9 scenarios, using 161 distribution records and 22 environmental variables. The model parameters were set to RM = 1.5 and FC = LQH, achieving a high prediction accuracy with an Area Under the Curve (AUC) value of 0.820.

RESULTS

The analysis identified key environmental factors influencing the suitable habitat of P. crystallophlomis, including annual precipitation (bio-12), temperature seasonality (bio-4), mean diurnal range (bio-2), and precipitation seasonality (bio-15). Under current climate conditions, the suitable habitats are primarily located in the eastern Qinghai-Tibet Plateau, Hengduan Mountains, and Yunnan-Guizhou Plateau, exhibiting significant fragmentation. Notable declines in potential habitat area were observed from the Last Glacial Maximum (LGM) to the Mid-Holocene (MH), with future projections indicating further reductions, particularly under the Shared Socioeconomic Pathways 585 (SSP-585) scenario.

CONCLUSION

The suitable habitat of P. crystallophlomis, which tends to grow in consistently cold and moist environments, is expected to shrink, with a projected southward shift in its centroid. Global warming is anticipated to profoundly impact the suitable habitats of P. crystallophlomis, highlighting the urgent need for conservation efforts.

Distribution Patterns of Platycodon grandiflorus From the Last Interglacial Period to the Future by Ecological Niche Modeling

Global climate change may represent a significant threat to the distribution and quality of medicinal plants, altering cultivation areas and compromising the quality of medical materials. Platycodon grandiflorus, a traditional Chinese medicinal herb, has a millennia-long medicinal and culinary use history in East Asia. Given its escalating demand, accurately evaluating the changes under different climate scenarios and predicting its potential distribution are imperative for ensuring its conservation and sustainable utilization. By integrating MaxEnt with ArcGIS, this study advances previous approaches by incorporating historical, present, and future climate data to model the distribution dynamics of P. grandiflorus across China. The results indicated: (1) The species' distribution strongly correlates with environmental variables, particularly bio13, prec07, prec09, and tmin07, whose cumulative value of percent contribution was 78.5%; (2) The centroids of potential geographic distribution during the LIG, LGM, and MH periods were situated further westward compared to the present distribution, with substantial contraction observed in highly suitable habitats throughout these historical periods; (3) Under present climatic conditions, the overall suitable habitat encompasses 4,185,964 km2, with highly suitable habitats constituting one-third of this expanse, predominantly concentrated in central, southern, and northeastern China; (4) Future climate change scenarios predict that the total suitable habitat will expand to varying degrees (7% increase on average), albeit with potential reductions in highly suitable areas (3% decrease on average); and (5) The distribution of P. grandiflorus is likely to move toward higher latitudes in the future due to climate changes. Our findings fill a critical knowledge gap by quantifying the impact of climate change on the distribution of P. grandiflorus. These results offer crucial insights for developing effective conservation strategies, promoting sustainable utilization, and establishing standardized cultivation protocols for P. grandiflorus resources.

Impacts of Climate Change and Human Activity on the Habitat Distribution of Metasequoia glyptostroboides

Extensive evidence supports that global climate change influences shifts in species habitats due to alterations in hydrothermal conditions; however, neglecting dispersal capacities and limits significantly heightens uncertainties regarding spatial distribution patterns among different organisms. In this study, we compared the spatial distribution of Metasequoia glyptostroboides Hu & W.C. Cheng (M. glyptostroboides) in the current Anthropocene context to that in a climate-only context, providing new insights into the effects of climate change, dispersal potential, and dispersal barriers on the habitat changes for M. glyptostroboides. By utilizing optimized MaxEnt and MigClim models, we predicted Mid-Holocene (MH) conditions and potential colonizable habitats under three emission scenarios (SSP126, SSP245, and SSP585) for both the medium and long term. We also assessed habitat distribution and variation differences in future warm-wet conditions and the Anthropocene context. The results revealed that (1) The Precipitation of driest month (BIO14), Mean diurnal range (Bio2) and human footprint (HFP) are the primary factors influencing the expansion or contraction of the habitats of M. glyptostroboides. Human footprint, farmland, roads, and construction land are the main contributors to habitat loss and fragmentation. (2) Habitats of M. glyptostroboides are expected to experience significant loss in the future. There is potential for recovery in South China under the SSP126 emission scenario, but human activities may hinder this recovery. Moderate human intervention is necessary in regions, such as Hubei, Hunan, Anhui, and Sichuan basins. (3) Due to human influence, the habitat and high-suitability areas for M. glyptostroboides are projected to migrate northeastward. Under the SSP126 scenario, a trend of reverse migration may be observed in the long term. This study minimizes the uncertainty in predicting species distribution under climate change while providing theoretical support for future habitat conservation of M. glyptostroboides.

Predicting the potential distribution of Astragali Radix in China under climate change adopting the MaxEnt model

Introduction

Astragali Radix is the dried root of Astragalus mongoliae or Astragalus membranaceus, a leguminous plant. Since ancient times, Astragali Radix has been widely used in Chinese traditional Chinese medicine. As people become more health-conscious, the market demand for Astragali Radix grows and its popularity is increasing in the international market. As an important medicinal plant, the growth of Astragali Radix is strongly influenced by environmental conditions. In order to meet the market demand for high quality Astragali Radix herbs, it is necessary to search and find areas suitable for the growth of Astragali Radix.

Methods

In this study, we assessed the potential impacts of climate change on the distribution of the Chinese medicinal plant Astragali Radix using the maximum entropy (MaxEnt) model in combination with a geographic information system(GIS). Distribution data and environmental variables were analyzed to predict suitable areas for Astragali Radix under the SSP126, SSP245 and SSP585 scenario for current and future (2041-2060, 2061-2080, 2081-2100). Jackknife is used to assess the importance of environmental variables, and environmental variables with a model contribution greater than 5% were considered to be the main drivers.

Results

The results showed that the current area of suitable area for Astragali Radix is 188.41 km2, and the three climate scenarios show an increasing trend in the future, with a maximum of 212.70 km2. North China has always been the main suitable area, while the area of suitable area in Southwest China is decreasing, and Xinjiang will be developed as a new suitable area in the future. Annual precipitation (41.6%), elevation (15.9%), topsoil calcium carbonate (14.8%), annual mean temperature (8.3%), precipitation seasonality (8%) and topsoil pH (6%) contributed more to the model and were the main environmental influences on the distribution of Astragali Radix. In addition, the centroids of the suitable areas shifted northward under all three climate scenarios, indicating a migratory response to global warming.

Discussion

Our study found that suitable area of Astragali Radix has been expanding for most of the time in each period of the three climate scenarios compared with the current situation. In the future, humans can focus on enhancing the cultivation techniques of Astragali Radix in these suitable areas. This study provide a scientific basis for the development of planting strategies and spatial distribution management of Astragali Radix. It helps to optimize the selection of planting areas and resource conservation of Chinese herbs.

The Potential Habitat Response of Cyclobalanopsis gilva to Climate Change

Cyclobalanopsis gilva, a valuable timber species in China, holds significant importance for understanding the constraints imposed by climate change on the dynamic geographic distribution of tree species. This study utilized the MaxEnt maximum entropy model to reconstruct the migratory dynamics of C. gilva geographical distribution since the Last Glacial Maximum. The objective was to comprehend the restrictive mechanisms of environmental factors on its potential geographical distribution, aiming to provide insights for mid-to-long-term afforestation planning of C. gilva. The optimized MaxEnt model exhibited a significantly high predictive accuracy, with an average AUC value of 0.949 ± 0.004 for the modern suitable habitat model of C. gilva. The total suitable habitat area for C. gilva in contemporary times was 143.05 × 104 km2, with a highly suitable habitat area of 3.14 × 104 km2. The contemporary suitable habitat was primarily located in the southeastern regions of China, while the highly suitable habitat was concentrated in eastern Fujian and central-eastern Taiwan. Bioclimatic variables such as mean diurnal range (Bio2), min temperature of coldest month (Bio6), precipitation of driest quarter (Bio17), and precipitation of driest month (Bio14) predominantly influenced the modern geographic distribution pattern of C. gilva, with temperature factors playing a leading role. With global climate warming, there is a risk of fragmentation or even loss of suitable habitat for C. gilva by 2050 and 2090. Therefore, the findings of this study can significantly contribute to initiating a habitat conservation campaign for this species.

Forest Orchids under Future Climate Scenarios: Habitat Suitability Modelling to Inform Conservation Strategies

Orchidaceae is one of the largest and most diverse families of flowering plants in the world but also one of the most threatened. Climate change is a global driver of plant distribution and may be the cause of their disappearance in some regions. Forest orchids are associated with specific biotic and abiotic environmental factors, that influence their local presence/absence. Changes in these conditions can lead to significant differences in species distribution. We studied three forest orchids belonging to different genera (Cephalanthera, Epipactis and Limodorum) for their potential current and future distribution in a protected area (PA) of the Northern Apennines. A Habitat Suitability Model was constructed for each species based on presence-only data and the Maximum Entropy algorithm (MaxEnt) was used for the modelling. Climatic, edaphic, topographic, anthropogenic and land cover variables were used as environmental predictors and processed in the model. The aim is to identify the environmental factors that most influence the current species distribution and the areas that are likely to contain habitats suitable for providing refuge for forest orchids and ensuring their survival under future scenarios. This will allow PA authorities to decide whether to invest more resources in conserving areas that are potential refuges for threatened species.

Distribution Pattern of Suitable Areas and Corridor Identification of Endangered Ephedra Species in China

The suitable habitat of endangered Ephedra species has been severely threatened and affected by climate change and anthropogenic activities; however, their migration trends and restoration strategies are still relatively understudied. In this study, we utilized the MaxEnt model to simulate the suitable habitats of five endangered Ephedra species in China under current and future climate scenarios. Additionally, we identified significant ecological corridors by incorporating the minimum cumulative resistance (MCR) model. Under the current climate scenario, the suitable area of Ephedra equisetina Bunge, Ephedra intermedia Schrenk ex Mey, Ephedra sinica Stapf, and Ephedra monosperma Gmel ex Mey comprised 16% of the area in China, while Ephedra rhytidosperma Pachom comprised only 0.05%. The distribution patterns of these five Ephedra species were primarily influenced by altitude, salinity, temperature, and precipitation. Under future climate scenarios, the suitable areas of E. equisetina, E. intermedia, and E. sinica are projected to expand, while that of E. monosperma is expected to contract. Notably, E. rhytidosperma will lose its suitable area in the future. Our identified ecological corridors showed that the first-level corridors encompassed a wider geographical expanse, incorporating E. equisetina, E. intermedia, E. sinica, and E. monosperma, while that of E. rhytidosperma exhibited a shorter length and covered fewer geographical areas. Overall, our study provides novel insights into identifying priority protected areas and protection strategies targeting endangered Ephedra species.