资源环境科技发展态势分析平台

Wood anatomical features such as vessels record paleo climatic and environmental signals through their physiological adjustment during the environmental stress condition. Using vessel features as environmental proxy is relatively new in tropical dendrochronology but very useful to study plant ecophysiological responses to changing environmental conditions. Here, we developed the first vessel chronologies of diffuse porous Chukrasia tabularis from a Bangladeshi moist tropical forest and assessed their suitability for Dendroclimatic and ecophysiological studies in moist tropical forests. Standard chronologies of ring-width (RW), vessel number (NV), mean vessel area (MVA), total vessel area (TVA), total vessel area % (TVAP), mean vessel tangential diameter (MVTD), mean vessel radial diameter (MVRD), and vessel density (VD) were developed which spanned the period 1925-2015. Principal component analysis revealed that all chronologies were related among each other, the first two principal axis explaining 80% of the common variance. Hence, all chronologies shared a common environmental signal, except TVAP and MVRD which were excluded from further dendroclimatic analysis. Bootstrap correlation function was used to test the relationship between the chronologies and climate variables over 1950-2015. All chronologies were significantly correlated with monthly, seasonal and annual climate variables but varied in their magnitude. Spring temperatures (March-April) and late monsoon precipitation had the dominant influence on the vessel features and radial growth of Chukrasia tabularis. Decreased vessel area (Hydraulic efficiency) and increased vessel density (Hydraulic safety) were observed in response to stress environmental condition particularly in the spring (hot and dry) when evapotranspiration became higher and soil moisture deficit occurs due to high temperatures. Moving correlation functions revealed stable climate tree-ring variable relationships during March-April and October with an increasing tendency of climate interaction in other months. Our study shows that vessel features in Chukrasia tabularis are highly sensitive to inter-annual climate variability and can be used for paleoclimatic and ecophysiological studies in moist tropical forests.