西藏纳木错植物物候及其对气候的响应

利用纳木错流域1O种代表性植物2007年和2008年的物候观测资料,分析了植物生殖物候的基本特征及气候条件对其的影响.植物最早5月中旬进入开花期,大部分植物的盛花期在6月中旬至7月下旬,开花的最适温度范围为8.5-8.9℃,花期延续到9月下旬.从6月上旬开始,大部分植物进入果期,多数植物果期与花期重叠.纳木错具有高寒地带植物物候的普遍特征:生长期较短(5个月左右)、早花现象、晚花现象.同2007年相比,2008年雨季提前,虽然气温偏低,大部分植物花期和果期普遍缩短5 d左右,但物候期提前约20 d.植物物候的年际变化对气候变化,特别是对降水量的季节分配更敏感.

Phenology Characters of Dominant Plants in the Nam Co Basin and Its Response to Climate,Tibet

Ten dominant plants of alpine meadow in the Nam Co basin were selected to observe their phenological features during 2007 and 2008. The earliest flowering occurred in the mid - May, and the maximum flowering period happened from the mid - June to late July for the majority of plants, then the flowering ended in the late September. The suitable air temperature for plant flowering ranged from 8. 5 ℃ to 8. 9 ℃. Plant fruiting began in the early June, and fruiting period was coherent with flowering period for most of plants. The general features of phenology in the high elevations with low air temperature were observed in the Nam Co basin, which are characterized by short growing seasons (around 5 months), early and late flowering. Rainy season onset was earlier in 2008 than that in 2007, which caused plant flowering onset was 20 days earlier, and flowering and fruiting periods were shortening around 5 days in 2008 than those in 2007. Annual changes in phenology are sensitive to climate variability, especially the seasonality of precipitation.