title: Field evidence for earlier leaf-out dates in alpine grassland on the eastern Tibetan Plateau from 1990 to 2006.
abstract: Worldwide, many plant species are experiencing an earlier onset of spring phenophases due to climate warming. Rapid recent temperature increases on the Tibetan Plateau (TP) have triggered changes in the spring phenology of the local vegetation. However, remote sensing studies of the land surface phenology have reached conflicting interpretations about green-up patterns observed on the TP since the mid-1990s. We investigated this issue using field phenological observations from 1990 to 2006, for 11 dominant plants on the TP at the levels of species, families (Gramineae-grasses and Cyperaceae-sedges) and vegetation communities (alpine meadow and alpine steppe). We found a significant trend of earlier leaf-out dates for one species (Koeleria cristata). The leaf-out dates of both Gramineae and Cyperaceae had advanced (the latter significantly, starting an average of 9 days later per year than the former), but the correlation between them was significant. The leaf-out dates of both vegetation communities also advanced, but the pattern was only significant in the alpine meadow. This study provides the first field evidence of advancement in spring leaf phenology on the TP and suggests that the phenology of the alpine steppe can differ from that of the alpine meadow. These findings will be useful for understanding ecosystem responses to climate change and for grassland management on the TP.
authors.affiliation: The Northwest Institute of Plateau Biology, The Chinese Academy of Sciences, Xining 810008, People's Republic of China Key Laboratory of Adaptation and Evolution of Plateau Biota, The Chinese Academy of Sciences, Xining 810008, People's Republic of China.
authors.forename: H K
authors.initials: HK
authors.lastname: Zhou
authors.affiliation: The Northwest Institute of Plateau Biology, The Chinese Academy of Sciences, Xining 810008, People's Republic of China Key Laboratory of Adaptation and Evolution of Plateau Biota, The Chinese Academy of Sciences, Xining 810008, People's Republic of China bqyao@nwipb.cas.cn.
authors.forename: B Q
authors.initials: BQ
authors.lastname: Yao
authors.affiliation: Qinghai Institute of Meteorological Science, The Chinese Academy of Sciences, Xining 810001, People's Republic of China.
authors.forename: W X
authors.initials: WX
authors.lastname: Xu
authors.affiliation: Research Centre for Eco-environmental Sciences, The Chinese Academy of Sciences, Beijing 100085, People's Republic of China.
authors.forename: X
authors.initials: X
authors.lastname: Ye
authors.affiliation: The Northwest Institute of Plateau Biology, The Chinese Academy of Sciences, Xining 810008, People's Republic of China.
authors.forename: J J
authors.initials: JJ
authors.lastname: Fu
authors.affiliation: The Northwest Institute of Plateau Biology, The Chinese Academy of Sciences, Xining 810008, People's Republic of China.
authors.forename: Y X
authors.initials: YX
authors.lastname: Jin
authors.affiliation: Chengdu Institute of Biology, The Chinese Academy of Sciences, Chengdu, 610041, People's Republic of China xqzhao@nwipb.cas.cn.
authors.forename: X Q
authors.initials: XQ
authors.lastname: Zhao
mesh_terms: D057231:Climate Change; D029786:Cyperus; D017753:Ecosystem; D065948:Grassland; D063245:Plant Development; D006109:Poaceae; D013696:Temperature; D018609:Tibet
keywords: Tibetan Plateau; alpine meadow; alpine steppe; climate change; leaf-out date; plant phenology
references.citation: Conserv Biol. 2009 Jun;23(3):520-30
references.pmid: 22748090
references.citation: Proc Natl Acad Sci U S A. 2011 May 10;108(19):E94; author reply E95
references.pmid: 21482817
references.citation: Proc Natl Acad Sci U S A. 2006 Sep 12;103(37):13740-4
references.pmid: 16954189
references.citation: Nature. 2003 Jan 2;421(6918):57-60
references.pmid: 12511952
references.citation: Proc Natl Acad Sci U S A. 2011 May 10;108(19):E93; author reply E95
references.pmid: 21482815
references.citation: Trends Ecol Evol. 2007 Jul;22(7):357-65
references.pmid: 17478009
references.citation: Nature. 2003 Jan 2;421(6918):37-42
references.pmid: 12511946
references.citation: Proc Natl Acad Sci U S A. 2013 Jun 25;110(26):E2329
references.pmid: 23661054
references.citation: Proc Natl Acad Sci U S A. 2013 Jul 30;110(31):E2856-7
references.pmid: 24058956
references.citation: Proc Natl Acad Sci U S A. 2010 Dec 21;107(51):22151-6
references.pmid: 21115833
references.citation: Proc Natl Acad Sci U S A. 2013 Jun 25;110(26):E2330-1
references.pmid: 23957057
references.citation: Proc Natl Acad Sci U S A. 2013 Mar 12;110(11):4309-14
references.pmid: 23440201
references.citation: Science. 2002 May 31;296(5573):1689-91
references.pmid: 12040195
references.citation: Proc Natl Acad Sci U S A. 2011 May 10;108(19):E91-2; author reply E95
references.pmid: 21482816
references.citation: Ambio. 2008 Jun;37(4):272-9
references.pmid: 18686506
references.citation: Proc Natl Acad Sci U S A. 2013 Jul 30;110(31):E2854-5
references.pmid: 23739768