气候变化对我国油松人工林适生区分布的影响

Effects of climate change on distribution of suitable area of Pinus tabuliformis plantation in China

【目的】油松是我国北方地区重要的针叶树种,根系发达,具有较强的水土保持和水源涵养能力,发挥着重要的生态防护功能。研究油松的生态特征及分布边界,探索油松的最佳造林区,了解油松人工林适生区分布在气候变化下的变迁,为气候变化背景下合理规划油松的造林和经营方案提供支持。【方法】基于油松人工林在中国地区221条有效分布记录和22个环境因子变量,结合ArcGIS,运用MaxEnt模型模拟气候变化情景下油松人工林的潜在分布,确定制约油松人工林分布的关键环境因子和适宜区间,预测油松人工林适生区在未来不同气候情景下的地理分布及面积的变化。【结果】(1)MaxEnt模型的AUC值达到0.955,说明模拟的结果可靠。(2)当前油松人工林在我国的适生区面积为98.90×10^(4) km^(2),集中分布在秦岭以北的地区,包括太行山、黄土高原、燕山和辽西等山地。影响油松人工林分布的主要环境变量为最暖季度降水量、最干季度平均温度、最冷月最低温度和海拔。其中,最暖季度降水量是影响油松人工林分布的首要因子,适宜范围为223~389 mm。最干季度平均温度的范围为-5~5℃,最冷月最低温度的范围为-14.5~-3.5℃,适合油松生长的海拔高度在100~2 100 m之间。(3)从1931—2020年的变化趋势来看,油松适生区的南界基本没发生变化,一直是岷山—秦岭—大巴山一线,向西到达祁连山南端和贺兰山东南侧,并没有向西北扩张。而油松适生区的北界却一直向北延伸,纬度大概向北扩张3.5°,高适生区重心同样也向北迁移。因此油松适生区面积一直呈增加的趋势。(4)从未来气候变化情景来看,在2041—2060年和2061—2080年两个时期,油松的潜在适生区继续呈现向北迁移的趋势,高适生区面积呈现先增加再减少的趋势。【结论】气候变化会导致油松适生区向北扩张,同时在黄土高原和秦岭地区高适生区呈现破碎化,引种栽培油松时需谨慎。在燕山北部和辽宁西部的高适生区范围比较稳定,适合继续扩大种植。

[Objective] Chinese pine(Pinus tabuliformis) is one of the most important conifer species for afforestation in the northern region of China,with well-developed roots and strong abilities in soil and water conservation,playing an important role in ecological protection.Studying the ecological characteristics and distribution boundaries of Chinese pine,exploring the optimal afforestation area and understanding the changes in the distribution of suitable area under climate change are prominent to formulate reasonable afforestation and management plan for Chinese pine,and to understand the adaptability of Chinese pine plantations to climate change.[Method] Based on 221 effective distribution records of Chinese pine plantation in China and 22 environmental variables,combined with ArcGIS,the MaxEnt model was used to predict the potential distribution of Chinese pine plantation under background of climate change.Meanwhile,the key environmental variables and suitable ranges that constrain the distribution of Chinese pine plantation were determined and the geographical distribution and area changes of Chinese pine plantation in different future climate scenarios were also predicted.[Result](1) The area under curve(AUC) value of the Maxent model reached 0.955,indicating the reliability of the simulation results.(2) The current suitable area of Chinese pine plantation in China was 98.90 × 10^(4) km^(2),concentrated in the north of Qinling Mountains,Taihang Mountains,the Loess Plateau,Yan Mountains of northern China and western Liaoning Mountains of northwestern China.The main environmental variables affecting the distribution of Chinese pine plantation were the precipitation of the warmest quarter,mean temperature of the driest quarter,min.temperature of the coldest month and altitude.Among them,precipitation of the warmest quarter was the primary variables affecting the distribution of Chinese pine plantation,with a suitable range from 223 to389 mm.Mean temperature of the driest quarter ranged from-5 to 5 ℃,and min temperature of the coldest month ranged from-14.5 to-3.5 ℃.The suitable altitude for the growth of Chinese pine plantation ranged from 100 to 2 100 m.(3) From the trend of changes in the past 90 years(1931-2020),the southern boundary of suitable area for Chinese pine plantation had remained basically unchanged,along the line of MinshanQinling-Daba Mountains,reaching the southern end of the Qilian Mountains and the southern side of the Helan Mountains to the west,without expanding to the northwest.However,the northern boundary of the suitable area for Chinese pine plantation had been extending northward,approximately 3.5° northward,and the center of gravity of the high suitability area had also migrated northward.Therefore,the area of suitable habitat for Chinese pine plantation had been increasing.From the perspective of future climate change scenarios,in the two periods of 2041-2060 and 2061-2080,the potential suitable area of Chinese pine plantation continued to show a trend of northward migration,and the area of high suitable area increased firstly and then decreased.[Conclusion] Climate change will lead to the expansion of suitable area for Pinus tabuliformis to the north,while high suitability area in the Loess Plateau and Qinling Mountains are fragmented.Therefore,caution should be exercised when introducing and cultivating Pinus tabuliformis.The high suitability areas in the northern part of Yanshan Mountain and the western part of Liaoning Province are relatively stable and suitable for further expansion of planting.