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Acta Prataculturae Sinica ›› 2018, Vol. 27 ›› Issue (1): 62-72.DOI: 10.11686/cyxb2017040

• Orginal Article • Previous Articles     Next Articles

Physiological responses of Kobresia humilis to different habitats in the alpine meadow of the Yellow River

LI Ji-lan1, 2, LI Xi-lai1, *, MA Fu-jun2   

  1. 1.College of Agriculture and Animal in Qinghai University, Xining 810016, China;
    2.College of Eco-Environment Engineering in Qinghai University, Xining 810016, China
  • Received:2017-02-14 Revised:2017-07-03 Online:2018-01-20 Published:2018-01-20

Abstract: Kobresia humilis is one of the dominant species in the alpine meadow. We analyzed the physiological and ecological characteristics of K. humilis growing in several different habitats in a small catch-pit with secondary tributaries draining into the Yellow River, near Nanqi village, Henan County, Qinghai Province. The habitats were hill top, hill slope, beach land, terrace 1, and terrace 2. We explored the interaction between K. humilis and soil factors in these habitats. Soil analyses showed that soil moisture, total nitrogen, total P2O5, available phosphorus, and organic matter were higher in the terrace 1, terrace 2, beach land, and hill top habitats, and lower on the hill slope. Beach land showed the lowest soil pH and total K2O, and highest available potassium content. Therefore, soil fertility was higher in the terrace 1, terrace 2, and beach land habitats. Because of the different catch-pits in the various habitats, total biomass was higher in the terrace 1, terrace 2, and beach land habitats, and lower in the hill top and hill slope habitats. K. humilis was distributed in every habitat except on the floodplain wetland in terrace 1, and it was the dominant species in the beach land habitat. Its coverage, importance value, biomass, and proportion of total biomass were higher in the beach land habitat than in the hill slope habitat. Catalase activity and the contents of malondialdehyde, soluble protein, soluble sugars, proline, and carotenoids were higher in K. humilis from the hill top, hill slope, and terrace 2 habitats than in K. humilis from other habitats, but the chlorophyll a and b contents were lower. These indexes showed the opposite trends in the beach land habitat. Correlation analyses between soil factors and the physiological characteristics of K. humilis showed that some physiological characteristics were strongly correlated with soil moisture, pH, and total K2O. According to these comprehensive analyses of K. humilis across a range of ecological habitats, we conclude that K. humilis is suited to growth on soil with low pH, and moderate moisture and nutrition status. It can adapt to its habitat by increasing its resistance and competitive abilities under the conditions of low soil moisture and low nutrient content.