西南地区寒温性针叶林乔木对气候变化的响应

Responses of Cold-Temperate Coniferous Forest to Climate Change in Southwestern China

为研究中国西南地区寒温性针叶林地理分布对气候变化的响应,以西南地区20种寒温性针叶林主要乔木树种地理分布数据为依据,通过最大熵(MaxEnt)模型和地理信息系统,结合气候、地形、土壤等环境因子,预测各乔木树种在未来(2070年)气候变化下的潜在适生区动态并分析潜在分布区的环境特征,旨在为气候变化下寒温性针叶林资源保护及可持续经营提供理论参考。结果表明,1)20个树种的地理分布模型的AUC值均>0.85,表明模型预测精度较高。2)2070年BCC-CSM2-MR模式SSPs126和SSPs245情景下,20种寒温性针叶林适生区整体呈现向高纬度、高海拔迁移的趋势;其中,苍山冷杉、冷杉、长苞冷杉、急尖长苞冷杉、鳞皮冷杉、大果红杉、云杉、丽江云杉、川西云杉、西藏云杉和青杄的潜在适生分布区均呈现扩张趋势,锡金冷杉、巴山冷杉、岷江冷杉、祁连圆柏、大果圆柏、麦吊云杉、青海云杉和紫果云杉的潜在适生区呈现缩小趋势,而川滇冷杉潜在适生区变化最小。3)寒温性针叶林地理分布的6个主导环境影响因子及范围依次为:海拔(1283~4800 m)>降水量(389~1623 mm)>气温的季节性(446~1073)>坡度(2°~34°)>等温性(30~52)>最冷月最低气温(-20~3℃)。

Based on the geographical distribution data of 20 main cold-temperate coniferous forest species and environmental factors such as climate,topography and soil,the potential habitat under the future climate change(2070)was predicted by the maximum entropy model(MaxEnt)to study the responses of geographical distribution of cold-temperate coniferous forest to climate change in Southwestern China.And environmental characteristics of potential distribution areas of the trees in the region were analyzed to provide theoretical references for the conservation and sustainable management of cold-temperate coniferous forest resources under climate change.The results showed that 1)the AUC values of the geographical distribution models of 20 tree species were more than 0.85,indicating high model prediction accuracy.2)Under the SSPs126 and SSPs245 climate scenarios of the 2070 BCC-CSM2-MR model,the suitable distribution areas of 20 cold-temperate coniferous forests would show a trend of moving to higher latitudes and altitudes.The potential suitable distribution areas of Abies delavayi,A.fabri,A.georgei,A.georgei var.smithii,A.squamata,Larix potaninii var.australis,Picea asperata,P.likiangensis,P.likiangensis var.rubescens,P.spinulosa and P.wilsonii showed an expansion trend.The potential suitable distribution areas of A.densa,A.fargesii,A.fargesii var.faxoniana,Juniperus przewalskii,J.tibetica,P.brachytyla,P.crassifolia and P.purpurea would decrease.The potential suitable distribution areas of A.forrestii would show the smallest change.3)The 6 dominant environmental impact factors of the cold-temperate coniferous forest geographical distribution were as follows:altitude(1283-4800 m)>precipitation(389-1623 mm)>temperature seasonality(446-1073)>slope(2°-34°)>isothermality(30-52)>minimum temperature of the coldest month(-20-3℃).