發(fā)布時(shí)間：2018-03-17 20:34

  本文選題：高寒草甸　切入點(diǎn)：群落特征　出處：《應(yīng)用生態(tài)學(xué)報(bào)》2017年12期 　論文類型：期刊論文

【摘要】：以青藏高原東北緣高寒草甸為對象,研究不同放牧強(qiáng)度下植物群落和土壤因子的變化,以及群落物種分布與土壤物理結(jié)構(gòu)和化學(xué)養(yǎng)分因子的定量關(guān)系.結(jié)果表明:放牧導(dǎo)致優(yōu)勢種為垂穗披堿草和大針茅的原植物群落發(fā)生分異,高強(qiáng)度放牧樣地優(yōu)勢種變?yōu)榘圆莺完幧奖廪６?低強(qiáng)度放牧樣地變?yōu)榇顾肱麎A草和冷地早熟禾.隨放牧強(qiáng)度增加,物種豐富度、重要值和生物量均顯著降低.各放牧強(qiáng)度樣地重要值的物種序列均可用對數(shù)模型進(jìn)行擬合;隨放牧強(qiáng)度增加,植物重要值累積到占整個(gè)群落重要值50%時(shí),需要的物種數(shù)降低.土壤速效P、速效K、緊實(shí)度、含水量、穩(wěn)定入滲速率和大團(tuán)聚體指標(biāo)隨放牧強(qiáng)度顯著變化,但變化規(guī)律不一致.CCA排序表明,土壤緊實(shí)度是放牧作用下影響群落物種分布格局的最關(guān)鍵因子.方差分解表明,土壤因子共解釋群落物種分布變異的30.5%,其中土壤物理性狀單獨(dú)解釋群落物種分布的22.8%,對群落物種分布的貢獻(xiàn)率最高,主要影響放牧干擾下高寒草甸植物群落物種的分布格局.
[Abstract]:The changes of plant community and soil factors under different grazing intensities were studied in alpine meadow in the northeast margin of Qinghai-Tibet Plateau. And the quantitative relationship between species distribution and soil physical structure and chemical nutrient factors. The dominant species of high intensity grazing plots were Kobresia humilis and Alfalfa sinensis, while the low-intensity grazing plots became Elaeagnus hypestris and bluegrass in cold land. With the increase of grazing intensity, species richness was increased. The species sequence of the important values of grazing intensity samples can be fitted by logarithmic model. With the increase of grazing intensity, the plant importance values accumulate to 50% of the whole community important values. Soil available P, available K, compactness, water content, stable infiltration rate and large aggregate index changed significantly with grazing intensity, but the order of change was not consistent. Soil compactness is the most important factor affecting species distribution pattern under grazing. Soil factors accounted for 30.5% of the variation of community species distribution, among which soil physical characters accounted for 22.8% of community species distribution alone, and the contribution rate to community species distribution was the highest, which mainly affected the distribution pattern of alpine meadow plant community under grazing disturbance.
【作者單位】： 甘肅農(nóng)業(yè)大學(xué)草業(yè)學(xué)院/草業(yè)生態(tài)系統(tǒng)教育部重點(diǎn)實(shí)驗(yàn)室/中-美草地畜牧業(yè)可持續(xù)發(fā)展研究中心;畢節(jié)市畜牧獸醫(yī)科學(xué)研究所;蘭州大學(xué)生命科學(xué)學(xué)院;
【基金】：國家重點(diǎn)研發(fā)項(xiàng)目(2016YFC0501902) 國家自然科學(xué)基金項(xiàng)目(31460635)資助~~
【分類號】：S812
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本文編號：1626368