Chin J Plant Ecol ›› 2014, Vol. 38 ›› Issue (2): 147-158.DOI: 10.3724/SP.J.1258.2014.00013

Special Issue: 青藏高原植物生态学:种群生态学

• Research Articles • Previous Articles     Next Articles

Responses of phenological characteristics of major plants to nutrient and water additions in Kobresia humilis alpine meadow

YE Xin1,2,3, ZHOU Hua-Kun2,*(), LIU Guo-Hua1, YAO Bu-Qing2, ZHAO Xin-Quan2   

  1. 1State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
    2Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China
    3University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2013-05-30 Accepted:2013-08-15 Online:2014-05-30 Published:2014-02-12
  • Contact: ZHOU Hua-Kun

Abstract:

Aims Phenology is a sensitive, integrated indicator of environmental changes. It is important to research the responses of phenological characteristics to environmental changes for understanding interactions between plants and environment, adaptive mechanisms and survival strategies. Our objective is to examine how phenological characteristics of plants respond to nutrient and water conditions in the eastern Qinghai-Tibet Plateau.
Methods Plant phenological characteristics in alpine Kobresia humilis meadow following nutrient and water additions from 2009 to 2011 were quantitatively analyzed by the methods of nested analysis of variance, phonological index and cluster analysis.
Important findings There were no significant differences in either green-up date or senescence date of plants with nutrient addition, but these dates in several dominant species of grasses, sedges and forbs were postponed following N and P addition. The treatments of nutrient and winter moisture addition moved up flowering dates of dominant species (p < 0.01) and green-up dates of forbs (p < 0.05). Effects of nutrient and summer moisture addition were inconsistent. The senescence dates of Elymus nutans and Scirpus distigmaticus were significantly postponed (p < 0.05) and forbs were postponed. Phenological characteristics of different species had significant differences with nutrient addition (p < 0.01): the senescence dates of Potentilla nivea were significantly postponed (p < 0.05), the senescence dates of Scirpus distigmaticus were significantly moved up (p < 0.05), but the different phenology responses of plants to the nutrient addition were based mainly on plant groups, with the green-up dates of grasses mostly postponed but the green-up dates of sedges moved up. Continuance of vegetative growth and vegetative period after fruiting were negative correlated. Phenological characteristics of plants were divided into three groups by cluster analysis. Phenological characteristics of the treatment of nitrogen-phosphorus-potassium mixed fertilizer, potassium and nitrogen-potassium mixed fertilizer addition varied considerably among plant groups. In summary, phenological characteristics of species in K. humilis meadow displayed large differences after moisture addition, but displayed smaller differences after nutrient addition.

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Key words: green-up date, moisture, nutrient, phenology, phenology index, senescence date