Chun-Jing Wang

Vulnerability of forest vegetation to anthropogenic climate change in China

China has large areas of forest vegetation that are critical to biodiversity and carbon storage. It is important to assess vulnerability of forest vegetation to anthropogenic climate change in China because it may change the distributions and species compositions of forest vegetation. Based on the equilibrium assumption of forest communities across different spatial and temporal scales, we used species distribution modelling coupled with endemics-area relationship to assess the vulnerability of 204 forest communities across 16 vegetation types under different climate change scenarios in China. By mapping the vulnerability of forest vegetation to climate change, we determined that 78.9% and 61.8% of forest vegetation should be relatively stable in the low and high concentration scenarios, respectively. There were large vulnerable areas of forest vegetation under anthropogenic climate change in northeastern and southwestern China. The vegetation of subtropical mixed broadleaf evergreen and deciduous forest, cold-temperate and temperate mountains needleleaf forest, and temperate mixed needleleaf and broadleaf deciduous forest types were the most vulnerable under climate change. Furthermore, the vulnerability of forest vegetation may increase due to high greenhouse gas concentrations. Given our estimates of forest vegetation vulnerability to anthropogenic climate change, it is critical that we ensure long-term monitoring of forest vegetation responses to future climate change to assess our projections against observations. We need to better integrate projected changes of temperature and precipitation into climate-adaptive conservation strategies for forest vegetation in China.

Expansion potential of invasive tree plants in ecoregions under climate change scenarios: an assessment of 54 species at a global scale

ABSTRACT Climate change may increase expansion risk of invasive tree plants (ITPs) worldwide. Ecoregions are the power conservation tool for the management of ITPs. However, few studies have investigated the relationship between ITP expansion and ecoregions at the global scale under climate change scenarios. Here, we provided a method to evaluate the expansion potential of 54 representative ITPs in ecoregions specifically under influences of the changing climate at the global scale. We found that climate change due to increasing greenhouse gas (GHG) concentration plays a positive role on the expansion of ITPs. We determined two of the most important ecoregion hotspots of ITP expansion potential, such as New Zealand and South Africa. In addition, ITPs were likely to have a large potential to expand in ecoregions of five different biomes, like temperate broadleaf and mixed forests. The potential expansion of ITPs would increase obviously in ecoregions of Boreal Forests/Taiga and Tundra. More importantly, the ecoregions of high elevation belonging to Tropical and Subtropical Coniferous Forests were expected to experience the higher expansion risk in the low GHG concentration scenario. Given our estimates of ITP expansion for ecoregions, management for the prevention and control for ITPs is urgent at the global scale.

Spatial conservation prioritization for dominant tree species of Chinese forest communities under climate change

Climate change is likely to threaten forests in future. Because dominant tree species (DTS) play central roles in stabilizing forest ecosystems, to effectively protect forests, we need to pay more attention to the protection of DTS. Furthermore, we need to integrate potential impacts of climate change into conservation efforts of DTS for improving forest protection. We utilized species distribution modeling, coupled with conservation planning, to establish climate-informed conservation prioritization for 136 taxa of DTS in three forest types (broad-leaved forests, mixed broadleaf-conifer forests, and coniferous forests) in China. We considered both current and future distributions and assessed the ability of existing nature reserves in China to protect forests based on these DTS. Regions with the highest climate-informed conservation prioritization were distributed in the southern, southwestern, and northeastern regions of China. There was a small gap between existing nature reserves and predicted conservation prioritization areas for conserving forests: the proportions of overlap between existing reserves and areas prioritized under climate change scenarios were 87.8, 95.7, and 80.4% for broad-leaved forests, mixed broadleaf-conifer forests, and coniferous forests, respectively. Even so, we need to increase the number and/or area of nature reserves to protect coniferous forests in Tibet, Sichuan, and Yunnan, and broad-leaved forests in Guizhou, Guangxi, Hu’nan, Yunnan, and Sichuan. Our results demonstrate the importance of conservation planning under climate change, taking both current and future distributions of plant species into consideration. Nature reserves should develop different management strategies for different forest types.

Identifying appropriate protected areas for endangered fern species under climate change

Abstract The management of protected areas (PAs) is widely used in the conservation of endangered plant species under climate change. However, studies that have identified appropriate PAs for endangered fern species are rare. To address this gap, we must develop a workflow to plan appropriate PAs for endangered fern species that will be further impacted by climate change. Here, we used endangered fern species in China as a case study, and we applied conservation planning software coupled with endangered fern species distribution data and distribution modeling to plan conservation areas with high priority protection needs under climate change. We identified appropriate PAs for endangered fern species under climate change based on the IUCN protected area categories (from Ia to VI) and planned additional PAs for endangered fern species. The high priority regions for protecting the endangered fern species were distributed throughout southern China. With decreasing temperature seasonality, the priority ranking of all endangered fern species is projected to increase in existing PAs. Accordingly, we need to establish conservation areas with low climate vulnerability in existing PAs and expand the conservation areas for endangered fern species in the high priority conservation regions.

The spatial distribution of threats to plant species with extremely small populations

Many biological conservationists take actions to conserve plant species with extremely small populations (PSESP) in China; however, there have been few studies on the spatial distribution of threats to PSESP. Hence, we selected distribution data of PSESP and made a map of the spatial distribution of threats to PSESP in China. First, we used the weight assignment method to evaluate the threat risk to PSESP at both country and county scales. Second, we used a geographic information system to map the spatial distribution of threats to PSESP, and explored the threat factors based on linear regression analysis. Finally, we suggested some effective conservation options. We found that the PSESP with high values of protection, such as the plants with high scientific research values and ornamental plants, were threatened by over-exploitation and utilization, habitat fragmentation, and a small sized wild population in broad-leaved forests and bush fallows. We also identified some risk hotspots for PSESP in China. Regions with low elevation should be given priority for ex- and in-situ conservation. Moreover, climate change should be considered for conservation of PSESP. To avoid intensive over-exploitation or utilization and habitat fragmentation, in-situ conservation should be practiced in regions with high temperatures and low temperature seasonality, particularly in the high risk hotspots for PSESP that we proposed. Ex-situ conservation should be applied in these same regions, and over-exploitation and utilization of natural resources should be prevented. It is our goal to apply the concept of PSESP to the global scale in the future.

Climatic niche divergence and habitat suitability of eight alien invasive weeds in China under climate change

Abstract Testing climatic niche divergence and modeling habitat suitability under conditions of climate change are important for developing strategies to limit the introduction and expansion of alien invasive weeds (AIWs) and providing important ecological and evolutionary insights. We assessed climatic niches in both native and invasive ranges as well as habitat suitability under climate change for eight representative Chinese AIWs from the American continent. We used climatic variables associated with occurrence records and developed ecological niche models with Maxent. Interestingly, the climatic niches of all eight AIWs diverged significantly between the native and invasive ranges (the American continent and China). Furthermore, the AIWs showed larger climatic niche breadths in the invasive ranges than in the native ranges. Our results suggest that climatic niche shifts between native and invasive ranges occurred. Thus, the occurrence records of both native and invasive regions must be considered when modeling and predicting the spatial distributions of AIWs under current and future climate scenarios. Owing to high habitat suitability, AIWs were more likely to expand into regions of low latitude, and future climate change was predicted to result in a shift in the AIWs in Qinghai and Tibet (regions of higher altitude) as well as Heilongjiang, Jilin, Liaoning, Inner Mongolia, and Gansu (regions of higher latitude). Our results suggest that we need measures to prevent and control AIW expansion at the country‐wide level.

Risk hotspots for terrestrial plant invaders under climate change at the global scale

Terrestrial plant invaders (TPIs) have a large potential to threaten plant diversity under climate change. To prevent the spread of TPIs under climate change, we must identify the risk hotspots for TPIs. However, the risk hotspots for TPIs have not yet been explicitly addressed at the global scale under climate change. Here, we selected 336 TPIs from the Invasive Species Specialist Group list and used species distribution modelling and Hot Spot Analysis to map the risk hotspots of TPIs based on the terrestrial ecoregions in the current, low and high gas concentration scenarios. The risk hotspots of TPIs were mainly distributed in South America, Europe, Australia, New Zealand and northern and southern Africa. Climate change may decrease the areas of hotspots that allow for TPI expansion, but the potential distribution probabilities of TPIs may increase in the high concentration scenario. Furthermore, TPIs, particularly herbaceous and woody ones, might still expand into critical or endangered ecoregions of these risk hotspots in the current, low and high concentration scenarios. We also need to focus on the impact of TPI expansion on both vulnerable and relatively stable ecoregions due to the increasing potential distribution probabilities of TPIs in risk hotspots and should integrate climate change into the risk assessment of plant invasion in the vulnerable and relatively stable ecoregions.

Impacts of the spatial scale of climate data on the modeled distribution probabilities of invasive tree species throughout the world

Abstract Species distribution models (SDMs) are powerful tools to predict species distributions, and thus support invasion risk assessments for tree species at the global scale. However, SDMs may produce different species distribution probabilities depending on the spatial scale of climate data included in the model. Hence, we must understand impacts of the climate data scale on the modeled distribution probabilities of invasive tree species (ITS) throughout the world. We used nine ITS from the list of “The 100 of the Worlds Worst Invasive Alien Species” as our study species, and applied Maxent modeling based on presence and background points to model the distribution probabilities of these ITS across the globe using three climate data scales: 2.5, 5.0 and 10.0′. The average distribution probabilities of presence and background points across the nine focal ITS increased significantly from the 2.5 to the 10.0′ resolution, indicating that coarse climate data scales may increase the distribution probabilities of presence and background points for these focal species. The large gap between different climate data scales resulted in high prediction uncertainty for the distribution probabilities of ITS. We offer two suggestions for decreasing the prediction uncertainty of the distribution probabilities of ITS at the global scale due to the effects of the climate data scale when using SDMs: 1) use 5.0′ resolution as the input to SDMs when using GBIF or other specimen databases; and 2) decrease the gap between 2.5, 5.0 and 10.0′ in the number of presence points of ITS.

Wind effects on habitat distributions of wind-dispersed invasive plants across different biomes on a global scale: Assessment using six species

Abstract A number of widespread invasive plants are wind-dispersed, and wind may facilitate their dispersal and migration over a large distance. While wind is an important factor for seed dispersal and pollination, few studies have examined its potential to affect the habitat distribution of invasive plants over large spatial scales. We selected six of the worlds worst invasive plants with wind-driving seed dispersal and pollination, and used wind speed as an indicator of wind. Environmental niche modelling was used to quantify the effects of wind on the habitat distribution of these invasive plants on a global scale and across 14 biomes. Wind had a negative effect on the habitat distribution of invasive plants in tropical and subtropical moist biomes, and a positive effect in Temperate Conifer Forests, Boreal Forests/Taiga, Temperate Grasslands, Savannas and Shrublands, and Montane Grasslands and Shrublands. We concluded that wind affected the habitat distribution of wind-dispersed invasive plants over a large scale, and this effect varied across different biomes. Thus, wind speed and biomes should be used as global monitoring indicators of invasion by wind-dispersed plants and wind speed variables should be included in the projection of habitat distributions of such invasive species when using ENM.

Erratum to: Protected areas may not effectively support conservation of endangered forest plants under climate change

Protected areas (PAs) play an important role in the conservation of valuable forest resources, and an increasing number of areas are being designated as PAs worldwide. However, climate change could drive endangered forest plants out of PAs, and impact the function of PAs to conserve endangered forest plants. Hence, it is necessary for conservation biologists to put forward a simple method to evaluate the ability of PAs to conserve endangered forest plants. Here, we studied 61 endangered forest plants from three ecoregions in China. We applied species distribution modeling to project suitable habitats of endangered forest plants, and used geographical information system to compute whether PAs could support the conservation of endangered forest plants. With climate change caused by increasing gas concentration, the overall ability of PAs to support the conservation of endangered forest plants will likely decrease compared to the conservation needs of ecoregions. We found that PAs have varying abilities to conserve endangered forest plants in different ecoregions. For temperate broadleaf mixed forests and tropical and subtropical moist broadleaf forests, we found that climate change will decrease the PAs’ ability to support the conservation of endangered forest plants effectively in the existing forest landscape. In contrast, we found that temperate conifer forests will likely remain effective. Using this information, we proposed the conservation plans for different ecoregions under climate change. For PAs with limited ability to support the conservation of endangered forest plants in an ecoregion, we recommend expanding the areas of forests and PAs based on the suitable habitats of the endangered forest plants. For PAs with stable ability to support the conservation of endangered forest plants in an ecoregion, we recommend expanding the conservation areas in PAs.