*4.3. Impacts on E. japonica Forest Ecosystems and Implications for Biodiversity Conservation*

At present, the frequency and severity of extreme weather events are also increasing year by year. Plants respond to climate change by adaptation, migration, or extinction. In our study, both algorithms and emissions scenarios predicted the spatial extent of suitable climate for *E. japonica* to geographically expand due to global warming, particularly in a northerly direction, especially in south

Shaanxi, central Anhui, north Henan, and Jiangsu, which, under current conditions, is recognized in the literature and our current climatic data-based model to be inappropriate. Those projected climate changes may provide migration opportunities for *E. japonica* to move into novel areas northward to the latitude barrier driven by climate.

However, the predicted shifts may also greatly affect the current *E. japonica* predominated ecosystems and may also affect the dependent/related flora and fauna. This may lead to the regional or local disappearance of *E. japonica*, and the presence or replacement of entire ecosystems by additional types of ecosystems [4]. The altered temperature and rainfall regimes can also give rise to *E. japonica* phenological shifts, and this may indirectly affect the dependent faunal and floral species. Moreover, climate change may adversely affect numerous insects, mammals, and terrestrial birds indirectly or directly because they rely on *E. japonica* seeds, fruits, and flowers [12]. Therefore, new guidelines will need to be created in support of sustainable forest management under predicted climate change.

First, our results may be adopted for categorizing those natural habitats into high or low risk in the presence of climate changes, to inform conservation planning. For example, under the future climatic situations, at high risk sites, land managers should introduce other species that were evaluated to be appropriate for specific climatic situations, rather than continue to make new plantations of *E. japonica*. Second, the models used here predicted that some areas may become climatically suitable for this species outside of its native range. Assisted migration may be used as a conservation strategy, which may help these species to reach the new appropriate sites in the presence of the changing climate [45]. In addition, *E. japonica* forests are extensively distributed across a broad climate range, and the species may also be able to adapt to new climatic conditions [2]. Therefore, it is important to exploit the phenotypic plasticity and to select appropriate adaptive genotypes for future climatic situations, so as to enhance the tolerance of *E. japonica* [41]. The 'no change' and 'gain' areas within the climatic space across various ecoregions for *E. japonica* identified in this study may serve as the possible refugia of climate change.
