割草对典型草原植物营养元素贮量及分配的影响I.植物生物量的贮量及分配

本文研究了内蒙古典型草原地区羊草（Ｌｅｙｍｕｓｃｈｉｎｅｎｓｉｓ）、艹洽草（Ｋｏｅｌｅｒｉａｃｒｉｓｔａｔａ）、其它草种和群落生物量的贮量及分配。结果表明：刈割对它们产生不同程度地影响。其产量高峰在８月３０日，此时割草地的上述植物生物贮量依次为５９．９２ｇ．ｍ－２、７．３２ｇ．ｍ－２、１２１．３２ｇ．ｍ－２和１８８．３５ｇ．ｍ－２，在割取的部分中所占的比例分别为５７．０３％、２１．５８％、４９．８１％和５１．０６％。对照区（不割草）依次为１０５．１３ｇ．ｍ－２、８．１０ｇ．ｍ－２、９７．０６ｇ．ｍ－２和２１０．３９ｇ．ｍ－２，在割取部分中的比例分别为６４．１９％、４１．８４％、５３．８１％和５８．５０％，割草区低于对照区。上述植物，地下部分生物量的贮量及分配比例的规律性不如地上部分明显，但总的趋势一致。割草区活根和根系残落物在８月３０日的总贮量为９３６．１２ｇ·ｍ３／２，活根占５２．４５％，根系残落物占４７．５５％。在活根中，羊草占４．８％、艹洽草占４．９２％、其它草占９０．２８％。对照区活根和根系残落物的总量为９４６．８８ｇ．ｍ３／２，活根占４７．７９％，根系残落物占５２．２１％。在活根的总量中，羊草占１?

INFLUENCE OF MOWING ON STORING AMOUNT AND DISTRIBUTION OF NUTRIENT ELEMENTS IN TYPICAL STEPPE 1.STORING AMOUNT AND DISTRIBUTION OF BIOMASS

The paper studies the storing amount and distribution of biomass of Leymus chinensis,koeleria.,cristata,other herbages and community of typical steppe in Inner Mongolia.The results obtained are as foloows:mowing has influence on them in varying degrees.The top period is on August 30 and the storing biomass of above herbages in the mowing area is 59.92g.m -2 ,7.32g.m -2 ,121.32g.m -2 and 188.35g.m -2 in turn,the percentages in mowing amount are 57.03%,21.58%,49.81% and 51.06%.The storing amount in the contrast area is 105.13g.m -2 ,8.10g.m -2 ,97.06g.m -2 and 210.39g.m -2 ,and the percentages in the mowing amount are 64.19%,41.84%,53.81%and 58.50%.In addition,the rule of storing amount and distribution of underground biomass isn't obvious as aboveground biomass,however,the trendence is identical.The total storing amount of living root and the litter of root system is 936.12g.m -2 on August 30,for the living root,the percentage is 52.45%,the litter of root system is for 47.55%.For the living root,leymus chinensis 4.80%,Koeleris cristata 4.92%,othr herbages 90.28%. The total storing amount of living root and litter of root system of the contrast area is 946.88g.m -2 ,of which,living root is 47.79%,litter of root system 52.21%.For the living root,Leymus chinensis 12.23%,Koeleria cristata 3.22%,other herbages 84.55%.