Global warming facilitates plant migration and biological invasion
地球暖化促进植物迁移与入侵

Global warming will lead to changes in many environmental factors and disturbance regimes (e g fire, drought, insect outbreak etc ) As a consequence, changes in characteristics of existing ecosystems, such as species composition and competition, stability and productivity, ecosystem health, ecological safety and ecosystem services, are to be expected Palaeoecological evidence and palaeoclimatic records pointed out plant pole ward migration in latitude and upward shift in elevation with increased temperature after the last glaciation Ecological observations also showed that the elevation of the alpine timberline moved upward worldwide with increasing global temperatures during the last 100 years Current global warming could mean that the plants currently growing at lower elevations or at lower latitudes might progressively migrate to higher elevations and latitudes However, it does not mean that all plants of an ecosystem move upward or pole ward with the same velocity Many species may re adapt to the changed and changing environmental conditions and survive for generations at their present location Many species will shift their ranges to track climate change As climate may change faster than plants are able to migrate from one region to another, species will become extinct An extinction of a plant species will also harm the animals depending on this specific species On the other hand, global warming and new disturbance regimes could favour the invasion of non native species due to the reduced stability and resistance of ecosystems Biological invasions will lead to massive losses of biological diversity on local, regional and global scales Global warming during the past 20 30 years has already had a severe impact on sensitive biological systems As a continued warming has to be expected, the global warming issue should be addressed by conservation planners and policy makers, as one of the most serious and immediate threats to biodiversity