Bingru Wang

Forest ecosystems are crucial for terrestrial ecosystem stability, particularly in carbon sequestration, nutrient cycling, and water conservation. With climate change exacerbating, understanding changes in suitable habitats for the main European tree taxa [Norway spruce (Picea abies), pedunculate oak (Quercus robur), and European beech (Fagus sylvatica)] and their drivers is critical for forest conservation in Europe. Here, we analyzed the factors driving the tree taxa distribution and suitable habitats under the current and two future scenarios, namely, optimistic and pessimistic. Based on a species distribution model, climatic, land use, and topographic factors were introduced as variables. This study determined that the main factors driving the tree taxa distributions were temperature, followed by land use. Under the future optimistic scenario, the suitable habitats change for the three tree taxa. Suitable habitats emerge in high-latitude regions and the northern Mediterranean. Meanwhile, suitable habitats are decreasing in Central Europe. Under the pessimistic scenario, more significant changes occurred in these regions. The total suitable habitat area for the three tree taxa did not change consistently under both scenarios. The suitable habitat area for Norway spruce increased, whereas that for pedunculate oak decreased. However, both regions with increasing or decreasing suitable habitats face the potential for forest succession, which will also affect the stability of forest ecosystem functions and should be a key focus.

The desert locust Schistocerca gregagia (Forskål, 1775) is one of the most harmful migratory pests in the world, posing a major threat to agricultural production, livelihoods, and food security. Climate, land use, and topography influence the distribution of desert locusts, but few studies have integrated all the factors on a global scale to explore the suitable areas for desert locusts and the paths through which this species could potentially spread. In this study, we established ensemble distribution models to investigate the distribution patterns and driving factors of desert locusts under baseline and future scenarios; we used ensembled niche dynamic models to evaluate their niche conservation during outbreaks. The results showed that the most important factor influencing desert locust distribution is climate, especially the minimum temperature of the coldest month, the annual precipitation, and the mean temperature of the driest quarter. Some areas with little or no desert locust distribution at present will be suitable for desert locusts in the future, and highly suitable contiguous areas may become the dispersal paths. The results also showed that the climatic niche of the desert locust is still conservative, which might explain why desert locusts tend to retreat after intermittent outbreaks rather than settle at the site of invasion. Therefore, more attention should be paid to the areas that are highly suitable for desert locusts, the key factors driving their outbreaks, and the shifting of their climatic niche in order to prevent desert locusts from settling in invasion areas and affecting local ecosystems and food security.

Human activities provide migration opportunities for many ornamental plants and make them become a new potential invasion risk, threatening the local ecosystem. However, ornamental plants come from a wide range of sources, and there is still a lack of understanding on the distribution driving factors, ecological niche dynamics and invasion ability of ornamental plants based on the origin of different latitudes to evaluate their potential invasion risks. In this study, an ensemble of ecological niche model and a niche dynamic model were used to analyze the invasion potential of herbaceous and woody ornamental plants originating from different latitudes. The results showed that there were significant differences in environmental factors driving the distribution of plants originating from different latitudes, and climate-related factors were the primary driving force for each plant in the native and introduced regions. Urban land was the most influential factor in the introduced areas of most plants, potentially reflecting the importance of human activities in the distribution of ornamental plants. Additionally, only woody plants originating from mid-latitudes showed greater diffusivity than those originating in high latitudes and low latitudes, and the niche widths of all the herbaceous plants in the introduced regions nearly exceeded those in the native regions. This phenomenon was observed only in woody plants with mid-latitude origins. The niche similarity of all plant species between the introduced and native regions was high, indicating that all species in the introduced regions inherited niche characteristics from plants in the native regions.