内蒙古大青山华北落叶松人工林乔木层碳密度年增量与气象因子的关系

以内蒙古大青山华北落叶松人工林为研究对象,通过树木年轮法和异速生长方程法,计算华北落叶松人工林生物量、碳密度及其年增量的年际变化,并分析碳密度年增量与气温、降水、湿度等气象因子的关系。研究发现：华北落叶松人工林碳密度随着林龄增加的变化曲线可用逻辑斯谛生长方程拟合,在1979—2016年,碳密度由1.05 t/hm~2增加到76.83 t/hm~2。华北落叶松人工林碳密度年增量存在显著的年际差异,总体上呈波动性的“慢-快-慢”趋势,碳密度年增量最高达到3.72 t hm^-2 a^-1,多年平均为2.05 t hm^-2 a^-1。华北落叶松人工林碳密度年增量与上年6月和当年6—8月的降水量显著正相关,与上年11月降水显著负相关;与上年11—12月、当年2月和12月的温度和大气相对湿度分别呈正、负相关;与上年7月、9月及当年8—9月的温度保持显著或极显著正相关。研究表明,温度、湿度和降水主要通过生长季的长短和土壤可利用水分及冬季的雪害冻害影响华北落叶松人工林的碳汇潜力,在未来该地区升温增湿的气候变化趋势下华北...

Relationship between carbon density increment of larch plantation and climate factors in Daqing Mountains of Inner Mongolia

Larch (Larix principis-rupprechtii) plantation is one of the main forest types in Daqing Mountains of the Inner Mongolia, China. To investigate the response of carbon density increment of larch plantation to varying climate factors, five 30×30 m² plots were set up in 43 years larch plantation in Hadamen National Nature Reserve of Daqing Mountains of Inner Mongolia. Diameter at the breast height (DBH) of all trees in the five plots was measured, and forty tree-ring samples at breast height were got in each plot. Then, using dendroecological methods and biomass-DBH growth equations, biomass, carbon density and carbon density increment of larch plantation were calculated, and the relation between carbon density increment with climatic factors, including monthly precipitation, monthly temperature (monthly mean temperature, monthly mean minimum temperature, monthly mean maximum temperature), and monthly mean humidity was analyzed. The results indicated that the variation of carbon density followed the logistic equation as the increase of forest age, and the larch plantation carbon density increased from 1.05 t/hm² in 1979 to 76.83 t/hm² in 2016. The carbon density increment of larch plantation showed a trend of "slow-fast-slow" with the increasing forest age, with a mean carbon density increment value of 2.05 t hm^-2 a^-1 and a maximum carbon density increment value of 3.72 t hm^-2 a^-1. The carbon density increment was closely correlated with climatic factors. The carbon density increment of larch plantation was significantly and positively correlated with the monthly precipitation in June of previous year and that from June to August of current year, but negatively correlated with December in previous year. The carbon density increment of larch plantation was significantly and positively correlated with the temperature from November to December of the previous year and February, December of current year, but significantly and negatively correlated with humidity in those months. There was positive correlation between carbon density increment and the monthly temperature in July, September of the previous year and August-September of current year. In general, annual varying of carbon density increment of larch plantation was mainly affected by temperature, humidity and precipitation, which were primarily through influenced the growing season length, the relative extractable soil water in growing season and freezing injury and snow damage in winter. It is implied that the carbon density increment of larch plantations would present an increasing trend in the future due to the warmer and humidor climate condition in the research region.