Climate-Induced Tree Growth Variations under the RCP 2.6 Scenario: A Case Study on the Southeastern Tibetan Plateau

Xianliang Zhang,Zhenju Chen,Fenghua Zou

doi:10.3390/f8100359

Abstract

The relationship between climate and radial tree growth is traditionally used to reconstruct past climate conditions based on interannual tree-ring variations. However, few studies have used these climate-growth relationships to model the radial tree growth based on future climate projections. To detect the future forest dynamics, the climate-induced tree growth from 2006 to 2100 was projected using temperature changes under representative concentration pathway (RCP) 2.6 for the southeastern Tibetan Plateau. Radial tree growth was mainly controlled by annual mean temperature in this region. Based on the relationship between regional annual mean temperature and radial tree growth, a regression model was built that explained 62.5% of variance in the observed temperature record over the period 1911–2005. A period of unprecedented radial tree growth was found after 1998 when compared with the tree growth in the past 700 years. We found that radial tree growth would increase in the period 2006–2045 and decline after that period due to the projected temperature decrease. As forest productivity and biomass are expected to increase with the increased tree growth, these results suggest that temperature-limited systems could see future increases in productivity as growth limitations are lessened. The results of this research could be used to predict regional forest dynamics in the future.

Highlights

Temperature increases are expected to be greatest at most high northern latitudes and high-elevation regions [1]
The relationship between the observed regional mean climate and the regional mean chronology was analyzed by correlation analysis for the common period 1957–2005 (Figure 5)
Total regional precipitation was positively correlated with the regional mean chronology in winter (p < 0.05)

Summary

Introduction

Temperature increases are expected to be greatest at most high northern latitudes and high-elevation regions [1]. The Tibetan Plateau has experienced a marked temperature increase, and has had a higher warming rate than the global average [2]. These changes have differential effects on the different ecotones throughout the world. Relationships between climate variables and radial tree growth have allowed for the robust reconstruction of past climate conditions on timescales that are not observationally possible. These relationships are assumed to be temporally stable, and future tree growth could be calculated through the use of projected climate conditions. Few studies have used the relationships established through tree-ring reconstructions to model future forest dynamics under variable climate conditions

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