Climate control on tree growth at the upper and lower treelines: a case study in the qilian mountains, tibetan plateau

PLoS One. 2013 Jul 11;8(7):e69065. doi: 10.1371/journal.pone.0069065. Print 2013.

Abstract

It is generally hypothesized that tree growth at the upper treeline is normally controlled by temperature while that at the lower treeline is precipitation limited. However, uniform patterns of inter-annual ring-width variations along altitudinal gradients are also observed in some situations. How changing elevation influences tree growth in the cold and arid Qilian Mountains, on the northeastern Tibetan Plateau, is of considerable interest because of the sensitivity of the region's local climate to different atmospheric circulation patterns. Here, a network of four Qilian juniper (Sabina przewalskii Kom.) ring-width chronologies was developed from trees distributed on a typical mountain slope at elevations ranging from 3000 to 3520 m above sea level (a.s.l.). The statistical characteristics of the four tree-ring chronologies show no significant correlation with increasing elevation. All the sampled tree growth was controlled by a common climatic signal (local precipitation) across the investigated altitudinal gradient (520 m). During the common reliable period, covering the past 450 years, the four chronologies have exhibited coherent growth patterns in both the high- and low-frequency domains. These results contradict the notion of contrasting climate growth controls at higher and lower elevations, and specifically the assumption that inter-annual tree-growth variability is controlled by temperature at the upper treeline. It should be stressed that these results relate to the relatively arid conditions at the sampling sites in the Qilian Mountains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Conditioning
  • Altitude
  • Climate*
  • Cold Temperature
  • Ecosystem*
  • Juniperus / growth & development
  • Temperature
  • Trees / growth & development*

Grants and funding

The study was jointly funded by the National Science Foundation of China (Grant Nos. 41071130), the CAS Strategic Priority Research Program Grant (Grant No. XDA05080801), the CAS 100 Talents Project (29082762), and the CAS Visiting Professorship for Senior International Scientists (Grant No. 2009S1-38). KRB and TMM acknowledge support from NERC (NE/G018863/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.