Articles | Volume 16, issue 10
Hydrol. Earth Syst. Sci., 16, 3835–3850, 2012

Special issue: Water, climate, and vegetation: ecohydrology in a changing...

Hydrol. Earth Syst. Sci., 16, 3835–3850, 2012

Research article 26 Oct 2012

Research article | 26 Oct 2012

Climate change, growing season water deficit and vegetation activity along the north–south transect of eastern China from 1982 through 2006

P. Sun1, Z. Yu1, S. Liu2, X. Wei3, J. Wang4, N. Zegre4, and N. Liu1 P. Sun et al.
  • 1Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China
  • 2Chinese Academy of Forestry, Beijing 100091, China
  • 3University of British Columbia (Okanagan), 3333 University Way, Kelowna, BC V1V 1V7, Canada
  • 4West Virginia University, Morgantown, WV 26506-6125, USA

Abstract. Considerable work has been done to examine the relationship between environmental constraints and vegetation activities represented by the remote sensing-based normalized difference vegetation index (NDVI). However, the relationships along either environmental or vegetational gradients are rarely examined. The aim of this paper was to identify the vegetation types that are potentially susceptible to climate change through examining their interactions between vegetation activity and evaporative water deficit. We selected 12 major vegetation types along the north–south transect of eastern China (NSTEC), and tested their time trends in climate change, vegetation activity and water deficit during the period 1982–2006. The result showed significant warming trends accompanied by general precipitation decline in the majority of vegetation types. Despite that the whole transect increased atmospheric evaporative demand (ET0) during the study period, the actual evapotranspiration (ETa) showed divergent trends with ET0 in most vegetation types. Warming and water deficit exert counteracting controls on vegetation activity. Our study found insignificant greening trends in cold temperate coniferous forest (CTCF), temperate deciduous shrub (TDS), and three temperate herbaceous types including the meadow steppe (TMS), grass steppe (TGS) and grassland (TG), where warming exerted more effect on NDVI than offset by water deficit. The increasing growing season water deficit posed a limitation on the vegetation activity of temperate coniferous forest (TCF), mixed forest (TMF) and deciduous broad-leaved forest (TDBF). Differently, the growing season brownings in subtropical or tropical forests of coniferous (STCF), deciduous broad-leaved (SDBF), evergreen broad-leaved (SEBF) and subtropical grasslands (STG) were likely attributed to evaporative energy limitation. The growing season water deficit index (GWDI) has been formulated to assess ecohydrological equilibrium and thus indicating vegetation susceptibility to water deficit. The increasing GWDI trends in CTCF, TCF, TDS, TG, TGS and TMS indicated their rising susceptibility to future climate change.