不同草地管理措施对狼毒型退化草地群落结构及牧草品质的影响

Effect of different management methods on the community structure and forage quality in Stellera-dominated degraded grassland

近年来,狼毒型退化草地在青海省境内分布广泛,对天然草地生产力及畜牧业发展危害严重。本研究通过采取不同的草地管理措施,包括自由放牧(对照)、禁牧(禁)、禁牧+防除狼毒(禁+防)、禁牧+刈割(禁+刈)、禁牧+防除狼毒+刈割(禁+防+刈)5种方式,对狼毒型退化草地的草产量、草地群落多样性以及牧草品质等指标进行了测定,以期探究对狼毒型退化草地恢复过程中较有利的管理措施。所得结果如下:1)总的地上生物量在禁+防处理下显著高于其他处理(P<0.05),其中,禾本科牧草生物量在禁+防处理下最高,莎草科植物生物量在各处理下无显著差异,而豆科和杂类草则在禁+刈条件下具有最高的生物量;2)就群落多样性而言,Shannon-Wiener指数、Simpson指数和均匀度指数均在禁+刈处理下具有最高值,但与对照相比差异不显著(P>0.05),而在禁+防处理条件下,此3种多样性指数均显著低于对照处理(P<0.05);3)牧草粗蛋白、粗脂肪、酸性洗涤纤维和中性洗涤纤维含量在各处理下差异均不显著(P>0.05),而粗灰分含量则在禁与禁+防处理条件下显著高于对照(P<0.05)。可见,若获得较高的草产量则禁+防处理最佳,而若要维持较高的群落多样性则宜采取禁+刈处理。该结果对狼毒型退化草地的恢复以及青藏高原天然草地毒杂草的控制研究提供了科学依据。

Over the years,Stellera-dominated degraded grasslands have become wide spread in Qinghai province,which cause severe harm to the production of natural grasslands and the development of livestock husbandry.To explore a more beneficial management measure for ensuring the recovery of Stellera-dominated degraded grassland,five different management measures were conducted[including free grazing(CK),grazing prohibition(GP),grazing prohibition+Stellera control(GP+SC),grazing prohibition+forage clipping(GP+FC),and grazing prohibition+Stellera control+forage clipping(GP+SC+FC)],and aboveground biomass,community diversity index,and forage quality were detected.The results showed that:1)the aboveground biomass was significantly higher in GP+SC than in other treatments.In addition,Gramineae species had the highest biomass under the GP+SC treatment.However,Sedge grass biomass had no significant difference among treatments.Leguminous species and forbs had the highest biomass under the GP+FC treatment.2)Shannon-Wiener index,Simpson index,and Pielou index were highest under the GP+FC treatment,and they had no significant difference as compared with CK.However,under the GP+SC treatment,these three indices were significantly lower than those of CK.3)The content of rude protein,crude lipid,ADF(acid detergent fiber)and NDF(neutral detergent fiber)in forage under different measures had no significant difference.However,the rude ash content of the forage was significantly higher under the GP and GP+SC treatments than under CK.Therefore,the GP+SC management measure is the best for grass production and maintenance of high species diversity in the grassland.The results provide a scientific basis for research on the reclamation of Stellera-dominated degraded grasslands.