关键词: 气候变化, 生态位模型, 华北落叶松, 油松, 蒙古栎

Abstract: [Objective] Exploring the relationship between geographical distributions of tree species and climatic factors, and predicting their suitable distribution area are essential steps for assessing the impact of climate change on forests and for providing a theoretical basis for developing adaptive forest management strategies.[Method]Based on the forest inventory data of Hebei Province, three tree species including Larix principis-rupprechtii, Quercus mongolica and Pinus tabulaeformis were selected. Ten climatic factors related to precipitation and temperature for current and two future periods (2040-2069 and 2070-2099) were achieved using a high-resolution climate model, i.e., ClimateAP. Moreover, the ecological niche model (MaxEnt) and three climate change scenarios (the lowest, moderate, and highest greenhouse gas emission scenarios:RCP2.6, RCP4.5, and RCP8.5) were applied to predict the consensual suitable distribution area of the three tree species in current and two future periods. Response curves method was used to analyze the influence of major climatic factors on the suitable distribution area of the three tree species.[Result]Results showed that the area under the receiver operating characteristics curves (AUC) for all the studied three tree species were more than 0.85, indicating MaxEnt model had a highly predictive performance. Currently these tree species were mainly distributed in the regions of Yanshan and Taihang Mountains in Hebei Province. The main climatic factors affecting the potential distribution of the three tree species were different. Larix principis-rupprechtii was mainly affected by the accumulative temperature below 0℃ and the mean precipitation of wet quarter; while Quercus mongolica was mainly influenced by the mean temperature of the warmest month. Hargreaves climatic moisture deficit and mean precipitation of wet quarter; and Pinus tabulaeformis was mainly affected by the mean temperature of the warmest month, the mean precipitation of wet quarter, the accumulative temperature above 5℃ and the mean annual temperature. Consensus projections for 2040-2069 indicated suitable areas for Larix principis-rupprechtii and Pinus tabulaeformis would substantially expand and decrease, respectively; while Quercus mongolica would remain relatively stable. Consensus projections for 2070-2099 indicated that suitable climate habitats for all these tree species would reduce significantly and the reduction range would exceed 3% in Hebei Province.[Conclusion]The results confirmed that the geographical distribution of these tree species might change under changing climate in the future. All these tree species showed an upward shift in elevation of the projected distribution, whilst no clear shift in latitude and longitude in the two future periods. Reforestation and afforestation could be an option in adaptive forest resource management to assist these species in expanding their migration to new suitable areas in the future. The above-mentioned adaptive strategy might be useful for improving forest productivity and maintaining a healthy forest ecosystem.

Key words: climate change, niche model, Larixprincipis-rupprechtii, Pinus tabulaeformis, Quercus mongolica