揭示大兴安岭北部气候变化敏感区的气候生产潜力演变及其影响机理,对于维持东北地区生态系统平衡具有重要意义。基于标准树轮年表反演气象资料与研究区13个气象站观测数据组成的17072014年气象资料序列,利用Miami模型和小波分析等方法,分析了大兴安岭北部气候生产潜力演变及其对气候变化的响应。结果显示: 1707年以来,气温、降水、蒸散和标准气候生产潜力变化均表现极显著增加趋势,标准气候生产潜力(W)变化率为1.79 kg hm~(-2) a~(-1),20世纪气候倾向率最大为10.14 kg hm~(-2) a~(-1),温度气候生产潜力(W_T )与降水气候生产潜力(WR )的比值21世纪最大,水热配比状态最好; 4种气候生产潜力存在不同时间尺度的周期变化,但变化一致性较好,主周期均为215219a;大兴安岭北部W呈现一致的正变化趋势,高值、次高值、低值中心分别在根河、塔河、鄂伦春偏南地区,振幅由西北向东南逐渐递减; W与年气温、降水量、蒸散量正相关显著,年平均气温每升高1℃、年降水量和蒸散量均增加10 mm,W变化率依次为453.71、74.40、219.01 kg /hm~2,且气温是影响W的主要因子;未来暖湿型气候对森林植被生长有利,而冷干型气候对森林植被生长不利,气候生产潜力增加(减少)幅度均为10.9% 21.7%。研究结果不仅可为区域尺度内研究森林植被气候生产潜力提供基础方法,而且对进一步估算森林碳汇、即将实施的碳交易及中国北部边疆生态安全研究和生态功能规划制定等具有重要参考价值。
英文摘要:
Understanding the evolution and mechanisms of climate-induced potential productivity in the climate change sensitive regions of northern Da Hinggan Mountain are fundamental for maintaining the ecosystem balance of northeastern China. The present study employed a meteorological data series from 1707 to 2014 by using standard tree-ring chronology data collection methods and observations from 13 weather stations in northern Da Hinggan Mountain region. Using a Miami model and wavelet analysis,we analyzed the evolution of climate-induced potential productivity and its response to climate change. Results show that four types of climate-induced potential productivity (air temperature, precipitation, evapotranspiration,and standard climate-induced potential productivity (W) ) have increased significantly (P≤0.001) since 1707. W has increased at a rate of 1.79 kg hm~(-2) a~(-1) in this region since 1707. During the 20~(th) century,the change rate of W caused by climate change peaked at 10.14 kg hm~(-2) a~(-1). During the 19th century,the change rate of W caused by climate change reached a minimum of 0.50 kg hm~(-2) a~(-1). These values of W were in the mid-range for the 18th(0.66 kg hm~(-2) a~(-1) ) and the 21~(st)(4.79 kg hm~(-2) a~(-1) ) ) centuries. The value of W for the analyzed centuries was ranked as the 21~(st)>20~(th)>18th >19th century. The ratio of temperature potential productivity (W_T ) to precipitation potential productivity (WR ) peaked in the 21~(st) century; this century also experienced the highest correlation between precipitation and temperature. The different time scales in the four types of climate-induced potential productivity changed periodically in the wavelet analysis,but was relatively consistent. The first major periodic oscillation of the wavelet analysis was 215219 years,and other major periodic oscillations in wavelet analysis were at 138,138,136,138 years. W showed a consistently positive trend in northern Da Hinggan Mountain,high,sub-high,and low values of W in Genhe,Tahe,and southern Elunchun Counties of northern Da Hinggan Mountain,respectively. That is,the amplitude of the W gradually decreased from northwest to southeast. Therefore,the geographical environment greatly influenced the value of W as it varied significantly across the region. Climate-induced potential productivity was relatively high in the region with a good correlation between temperature and precipitation. The regional ecosystems are obviously dominated by forest vegetation with lush growth in northern area where the original forest landscape remained more intact than in the south where secondary forest vegetation is dominant. In addition,W was significantly positively correlated with annual air temperature,precipitation,and evapotranspiration. A 1℃ increase in mean annual air temperature and 10 mm increase in annual precipitation and evapotranspiration could induce an increase in W by 453.71,74.40,219.01 kg /hm~2 in standard climate-induced potential productivity,respectively. Overall, air temperature is the main factor influencing any change in W. In the future,a warm-wet climate will be beneficial for the growth of forest vegetation,whereas a cold-dry climate will be unfavorable. Climate change is expected to create a warmerwetter climate in northern Da Hinggan Mountain region,which could increase the potential productivity. If the temperature increases (or decreases) 12℃,precipitation increase would be expected to increase (or decrease) 10%20%,and the potential productivity based on climatic conditions would increase (or decrease) within a range of 10.9 to 21.7%. These results may provide a basic method for studying potential productivity based on climate change for forest vegetation at regional scales,and an important reference value for future estimations of forest carbon-sinks,implementing carbon trade in the near future,studying ecological security,and formulating ecological function planning in China's northern border.