呼伦贝尔沙地樟子松树轮对气候变化的响应1）

在呼伦贝尔沙地中部鄂温克巴彦嵯岗和红花尔基地区共采集沙地樟子松（ Pinus sylvestris var．mon-golica）树轮样芯69个，成功建立了鄂温克、红花尔基两地樟子松轮宽差值年表，用相关函数分析了沙地樟子松的气候限制因子及气候变化对其径向生长的影响。结果表明：气温和降水量同时影响该地区樟子松的径向生长，鄂温克与单一的气候因子均不相关。红花尔基树轮宽度分别与当年6、9月份的气温呈显著负相关；分别与6、9月份的最高温度呈显著负相关；分别与6、8月份的最低温度呈负相关关系；红花尔基树轮指数还与前一年12月份降水量呈显著负相关。鄂温克树轮宽度仅分别与当年7、8月份的帕默尔干旱指数（ PD，S，I ）呈显著负相关；红花尔基樟子松树轮宽度也与当年秋季（8、9、10月份）的PD，S，I显著相关。这表明水分可利用性是沙地樟子松径向生长的最重要影响因子。特征年分析进一步验证了响应分析的结果，即6月份的高温少雨不利于沙地樟子松的生长。

Response of Pinus sylvestris var.mongolica Tree-ring Width to Climate Change in Hulunbuir Sandy Land,Chi-na

We collected 69 tree-ring cores of Scots pine ( Pinus sylvestris var.mongolica) from Ewenke and Honghuaerji in Hu-lunbuir sand land , and developed two residual chronologies .By correlation analysis between the tree-ring index and climat-ic factors, the radial growth of sandy Pinus sylvestris var.mongolica was affected by both precipitation and temperature .Ra-dial growth of Scots pine in Ewenke was not correlated with the single climate factor .Radial growth of Scots pine in Hong-huaerji was significantly negatively correlated with June and September temperature in current year .It was significantly neg-atively correlated with maximum temperatures in June and September and with minimum temperatures in June and August . Honghuaerji chronology was negatively correlated with December precipitation of the previous year .The chronology of Ew-enke was significantly negatively correlated with Palmer Drought Severity Index (PDSI) in July and August, while the chronology of HHEJ was negatively correlated with PDSI in autumn (August-October).The water availability was the most important factor in radial growth of Scots pine. The point year analysis further verified the results of the response function a-nalysis, indicating the high temperature and less rainfall of June was not conducive to the growth of Scots pine .