高寒草甸植被耗水量及生物量积累与气象因子的关系

分析高寒草甸植被生育期耗水量及植被生物量积累与气象因子的关系,结果表明植被生育期耗水量呈单峰型变化过程,7月耗水量最大。初期营养生长阶段的5月耗水量、植被生物量均较低,水分影响着植物的初期营养生长但不甚显著;植物旺盛生长的6～7月,耗水量高,而生物量波动明显,温度和水分均影响到生物量的提高,且水分是影响植被生长的关键因素;植物生长末期的8～9月,耗水量及植被阶段累积生物量均较低,水分条件充足,并非是植物生长的限制因素。海北高寒草甸地区植被年地上净初级生产量、地下净初级生产量、净初级生产量与植被耗水量关系不明显。而与相应的温度具有较显著的正相关关系。表明高寒草甸地区植被净初级生产量受温度条件限制的影响比水分条件更为明显。

Water consumption of alpine meadow and the influence of the meteorological factors on the vegetation biomass accumulation

Analysis on variation characteristics of vegetation water consumption and the influence of the meteorological factors on the vegetation biomass during growing season over the alpine meadow showed that the water consumption appeared as a shape of single peak type and its maximum value was present in July.In May,at the initial growth of plant,water consumption and biomass both were low and the water influenced on plant growth but not significantly;In June and July,at the vigorous growth of plant,water consumption was high,and the biomass varied yearly.Temperature and water could both influence on the increase of the biomass and water was the key factor.In August and September,at growth telophase,water consumption and accumulative biomass were low.Water was sufficient and not a limiting factor for the plant growth.In Haibei alpine meadow,there was no evident influence of plant water consumption on aboveground net primary production,belowground net primary production,and net primary production.However,the corresponding temperature variable correlated positively and significantly with primary production.The results indicated that the ecosystem plant net primary production in alpine meadow was limited by temperature more evidently than by water conditions.