青海省海北地区高寒草甸群落特征和生物量对短期休牧的响应

为揭示高寒草甸植被群落特征和生物量对短期休牧的响应,为高寒草甸合理利用提供依据,于2017年9月上旬采用样方法对青海省海北州门源县的连续放牧、生长季休牧和禁牧1年的高寒草甸样地进行调查、取样和分析,研究了短期休牧对高寒草甸植被群落结构和地上/地下生物量的影响。结果表明:1)生长季休牧和禁牧1年较连续放牧极显著提高了高寒草甸的群落高度、群落盖度和样方物种丰富度(P<0.01),极显著提高了异针茅、矮嵩草、异叶米口袋和青海苜蓿等代表性牧草高度(P<0.01);2)生长季休牧和禁牧1年较连续放牧极显著提高了枯落物量和半腐殖质量(P<0.01),极显著提高了禾本科、豆科和阔叶类植物生物量(P<0.01),极显著提高了总地上生物量和优质牧草产量(P<0.01);3)生长季休牧和禁牧1年较连续放牧极显著提高了表层地下生物量(0~10 cm)和总地下生物量(0~30 cm)(P<0.01)。对于青海海北地区的未退化高寒草甸,可以采用短期休牧技术优化其群落结构,提高生物量和优质牧草产量,促进天然草地资源合理利用。

Response of plant community structure and biomass to short-term rest grazing in an alpine meadow in Haibei Autonomous Prefecture of Qinghai

This study explored the effects of short-term rest grazing on plant community structure and biomass, in order to provide a theoretical basis for decisions on the sustainable utilization of alpine meadow grassland. The plant community structure and biomass at three study sites (continuously grazed [CG], rest grazing for a growing season [RGGS], and not grazed for one year [NG1Y]) in Haibei alpine meadow were sampled and analyzed, in early September 2017. It was found that: 1) RGGS and NG1Y significantly increased plant community height, ground cover and species richness compared to CG (P<0.01). These treatments also increased the height of representative species such as Stipa aliena, Kobresia humilis, Gueldenstaedtia diversifolia and Medicago archiducis-nicolaii (P<0.01). 2) RGGS and NG1Y significantly increased litter fall and humus accumulation (P<0.01), significantly increased grass, legume and broad-leaved herb species biomass (P<0.01), and also significantly increased total aboveground biomass and high quality forage yield, compared to CG (P<0.01). 3) RGGS and NG1Y significantly increased 0-10 cm belowground biomass and total belowground biomass (0-30 cm) (P<0.01). Therefore, short-term rest grazing can be used to benefit vegetation community structure, improve high quality herbage yield and promote sustainable utilization of alpine meadow in Haibei Autonomous Perfecture of Qinghai province.