不同载畜率下短花针茅分蘖特征和贮藏养分的变化

Changes of Tiller Characteristics and Storage Nutrient of Stipa breviflora under Different Stocking Rates

在短花针茅荒漠草原连续放牧14a的随机区组试验平台上,设4个载畜率水平,分别为0(对照CK)、0.91羊单位/hm^2·半年(轻度放牧LG)、1.82羊单位/hm^2·半年(中度放牧MG)和2.71羊单位/hm^2·半年(重度放牧HG),研究不同载畜率下短花针茅分蘖特征及根、茎基中贮藏总糖、可溶性糖、还原糖和粗蛋白质含量的变化及之间的相关性。结果表明:重度放牧下短花针茅茎基粗蛋白质含量显著提高,分蘖数显著增多;分蘖数与茎基粗蛋白质含量之间极显著正相关(r^2=0.17,P<0.001);各处理下,短花针茅茎基贮藏养分含量均高于根系。短花针茅于茎基中贮藏较多粗蛋白质,促进分蘖,减少过度放牧伤害。

Tillering is a kind of asexual reproduction of Stipa breviflora,the content of nutrients that plants produced and stored through photosynthesis can affect the emergence of tillering.The project set four stocking rate:grazing prohibition (CK:0),light grazing (LG:0.91 sheep unit/hm^2 · 6 months),moderate grazing (MG:1.82 sheep unit/hm^2 · 6 months),and heavy grazing (HG:2.71 sheep unit/hm^2 · 6 months) on a randomized block experimental platform for 14 years of continuous grazing in Stipa breviflora desert grassland,in order to study the tillering characteristics of Stipa breviflora and the changes in the contents of total sugar,soluble sugar,reducing sugar and crude protein stored in roots and stems under different stocking rates and the correlation between them.The results showed that heavy grazing significantly increased the content of crude protein in the stem base and the tiller number of S.breviflora;There was an extremely significant positive correlation between the content of stem basal crude protein and tiller number (r^2 = 0.17,P<0.001);Under each treatment,the content of stored nutrients in the stem base of S.breviflora was higher than that of root system.The higher content of crude protein stored in the stem base of S.breviflora promoted tillering and reduced overgrazing injury.