高山草地不同经济类群植物地上生物量和总磷量积累的季节动态

SEASONAL DYNAMICS OF ABOVEGROUND BIOMASS AND GROSS PHOSPHORUS FOR THE FOUR ECONOMIC HEREAGE GROUPS IN ALPINE GRASSLAND

为了系统测定高山草地不同经济类群植物地上于物质和总磷积累的季节动态规律，用“收获法”测定其地上干物质积累量，用“钼锑抗比色法”测定其含磷量，结果表明：高山草地禾本科草类、莎草类、杂类草和毒草地上干物质量与总磷量积累的季节变化趋势相吻合，均呈单峰曲线。禾本科草类峰值出现于９月初，莎草类、杂类草和毒草峰值出现于８月初。禾草类、莎草类、杂类草和毒草四个经济类群植物地上于物质积累的峰值分别为１９２９．７、１１７７．８、１１０１．３和３ｍ．１ｋｇ／ｈｍ￣２，总磷量积累的峰值分别为２．４４、１．５７０、２．２１０和０．６６６８ｋｇ／ｈｍ￣２。这类草地对家畜属于贫磷草地。８月份后，高山草地干物质积累具有稳定性，为发展季节畜牧业提供了可能性。

In order to test the Seasonal dynamics of aboveground dry matter and grcos phosphorus accumulationfor different economiC herbages in alpine grassland,“Harvest method”and“Mo一Sh Anti一ColorimetricAnalysis”were respectively used to test aboveground dry matter and gross phosphorus accumulation. Theresults showed that the seasonal dynamics of the aboveground dry matter were agreed with that of the grossphosphorus accumulated in grasses.sedges forbs and poisonous weeds in alpine grassland.The peak values ofaboveground dry matter and gross phosphorus accumulated in grasses appeared on September 1,and thoseaccumalated in the other groups occured on August 1.Peak values of aboveground dry matter for the foureconomic groups were 1929.7.1 177.8.1101.3 and 320.1kg/hm￣2 and the values of gross phosphorus were2.443,1.570.2.240 and 0.6667kg/hm￣2 respectively.These types of grassland contain poor phosphorusfor animals.The aboveground dry matter in alpine grassland accumulats steadily after August,which pro-vide a possibility in developing seasonal animal husbandry.