气候变化驱动下黄土高原刺槐林气候适宜性和脆弱性

刺槐是黄土高原乡土树种，具有优良的水土保持和固碳功能。黄土高原生态恢复实践中实施了大规模的植树造林，刺槐林面积占沟壑丘陵区人工植树造林面积90%以上。由于种植时没有考虑刺槐的气候适宜性，一些地区的刺槐林出现了退化现象。采用最大熵模型，在0.5km×0.5km空间精度上分别模拟了1961—1990、1966—1995、1971—2000、1976—2005、1981—2010,以及2100年(典型浓度路径RCP4.5和RCP8.5气候情景下)黄土高原刺槐的气候适宜性和敏感性。模拟结果显示：黄土高原刺槐分布及其动态变化主要受到最冷月温度、极端低温、降水量、年辐射量等气候因子影响，低温(最冷月温度、极端低温)是影响刺槐的最关键因子。黄土高原西北和北部广大地区，自然环境条件不适合刺槐林生长；黄土高原东南部(关中平原和山西南部)比较适合刺槐生长。相对1961—1990年，1961—2010年期间刺槐林适宜区分布格局基本没有改变，RCP4.5和RCP8.5气候情景下刺槐林适宜区分布格局也没有显著改变。图层叠加分析发现，刺槐的气候适宜度(即存在概率)发生了明显改变。黄土高原西部和北部属于不适宜刺槐生...

Climate suitability and vulnerability of Robinia pseudoacacia forest driven by climate change on the Loess Plateau

Robinia pseudoacacia is a native tree species on the Loess Plateau, which has excellent functions of soil and water conservation, and carbon sequestration. Large scale afforestation was carried out in the practice of ecological restoration in the Loess Plateau, and the area of Robinia pseudoacacia forest accounted for more than 90% of artificial afforestation in the gully and hilly areas. However, Robinia pseudoacacia forest degenerated in some areas because climate suitability of Robinia pseudoacacia was not considered during afforestation. In this study, MaxEnt (maximum entropy model) was used to simulate the climate suitability and sensitivity of Robinia pseudoacacia on the Loess Plateau in 1961-1990, 1966-1995, 1971-2000, 1976-2005, 1981-2010, and 2100 (under the climate scenarios of Representative concentration pathway RCP4.5 and RCP8.5, respectively) at the spatial resolution of 0.5 km × 0.5 km. The simulation results showed that the distribution and dynamic changes of Robinia pseudoacacia on the Loess Plateau were mainly affected by the coldest month temperature, extreme low temperature, annual precipitation, annual radiation and other climate factors. Low temperature (the coldest month temperature, extreme low temperature) was the most important factor affecting Robinia pseudoacacia. The natural environment was not suitable for Robinia pseudoacacia forest in the northwest and the north of the Loess Plateau, but it was suitable in the southeast (the Guanzhong Plain and the south of Shanxi Province) of the Loess Plateau. Compared with the period of 1961-1990, the geographical distribution pattern of Robinia pseudoacacia forest was basically unchanged during 1961-2010, and its geographical distribution pattern was not significantly changed under the climate scenarios of RCP4.5 and RCP8.5. Overlay analysis showed that climate suitability (namely exist probability) of Robinia pseudoacacia changed significantly. The regions in the west and north of the Loess Plateau were not suitable for Robinia pseudoacacia, where belonged to non-sensitive areas. The regions in the east and southeast were suitable for Robinia pseudoacacia, where was very sensitive to climate change, especially in the south central of Shanxi Province and the Guanzhong Plain in Shaanxi Province, showing significant climate vulnerability. This study has important reference value for choosing suitable area for afforestation, optimizing the spatial distribution of plantation, coping with climate change risk, maintaining the sustainable and healthy development of forest ecosystem on the Loess Plateau.