气候变化对东北沼泽湿地潜在分布的影响

东北地区是我国沼泽湿地分布最广泛的地区。为研究沼泽湿地对气候变化的响应,选取了对沼泽湿地分布可能存在影响的26个环境因子,利用最大熵(Maximum Entropy, MaxEnt)模型模拟了沼泽湿地基准气候条件下的潜在分布,并预测了气候变化情景下2011-2040 年、2041-2070 年和2071-2100 年3个研究阶段东北沼泽湿地潜在分布。研究结果表明:最大熵模型预测精度较高(平均AUC(Aera Under Curve)为(0.826±0.005))。基准气候条件下东北沼泽潜在分布区主要为大小兴安岭和三江平原地区。随着时间的推进,东北地区沼泽湿地原有潜在分布面积明显减少,而新增潜在分布面积较少,总面积呈现急剧减少趋势。至2071-2100年,原有沼泽湿地潜在分布面积将减少99.80%,新增潜在分布面积仅2.48%,总潜在分布面积减少97.32%。空间分布上,东北沼泽湿地潜在分布呈现由东向西迁移,南北向中心收缩的趋势。研究结果可为东北地区沼泽湿地保护政策的制定提供参考。

Prediction of the effects of climate change on the potential distribution of mire in Northeastern China

Mire, known as the ecosystems would be the most vulnerable to climate change, is widely distributed in the Northeastern (NE) China, and the NE China is one of the regions that would be mostly affected by the changing climates since the climate changes would mostly affect the area in higher latitudes. Therefore, studies of the spatial distributions of suitable habitats for mire in this region under future climate is obviously more important to conservation, restoration and mitigation among ecosystems, species distributions and climate changes. Based on the mire distribution data from the 1:4000000 Mire Map and 26 environmental factors in the NE China, the potential distributions of mire were predicted under the projected climate scenarios of current (1961-1990) and three future time-slices (2011-2040, 2041-2070, 2071-2100) through Maximum Entropy (MaxEnt) model as well as ArcGIS spatial analysis modules. The accuracy of predictions were accessed by the area under the curve (AUC) values of receiver operating characteristic (ROC) curve, and validation results showed that the predictions with MaxEnt model had a higher precision (mean AUC=0.826±0.005), and were credible and acceptable. The results for mire distribution showed that mire had a wide potential distribution range in the NE China, especially it mainly distributed in Great and Small Khingan Mountains and Sanjiang Plain under the current climate (based on the climate data from 1961-1990 years). However, the potential distribution area of mire decreased rapidly in NE China with changing climates since the new climate pattern would create new suitable habitat and make the currently suitable habitats would turn into unsuitable habitat for mire distribution, furthermore, the losing habitat rate was most higher than creating new habitat rate in this region under the changing climate. By 2011-2040 years, the current potential distribution area of mire reduced by 90.70%, the new suitable potential distribution area increased by 12.48%, the total potential distribution area of mire decreased by 78.22%. By 2041-2070 years, the current potential distribution area of mire reduced by 99.21%, the new suitable potential distribution area increased by only 3.23%, the total potential distribution area of mire decreased by 95.98%. By 2071-2100 years, the current potential distribution area of mire reduced by 99.80%, the new suitable potential distribution area increased by only 2.48%, the total potential distribution area of mire decreased 97.32%. As for spatial distribution, main distribution area of mire would shift from east part to west part at the longitude direction and shrink from the south and north part to central part of the region at latitude direction. By 2011-2040 years, the main potential distribution area of mire would shift to the northern part of Great Khingan Mountains, Songnen Plain, and Sanjiang Plain. By 2041-2070 years, the main potential distribution area of mire shifted to Hulunbeir Plateau, Songnen Plain, and Sanjiang Plain. By 2071-2100 years, the main potential distribution area of mire shifted to Hulunbeir Plateau and Songnen Plain. These results would provide important basis for making scientific management of mire and developing the measure for restoration mire and mitigating future climatic change in NE China.