Intra-and interannual climate variability drives the radial growth of Pinus wallichiana in the Nepalese Himalayas

Abstract

ABSTRACT Background The Himalayas have been experiencing a higher rate of temperature increase than the global average. How such climate warming and changes in the precipitation regime may affect the growth responses of individual tree species is little known but is required so that adequate projections of future distributions and management plans can be formulated. Aims This study was carried out to investigate the influence of intra- and interannual climate variability on the radial growth of Pinus wallichiana, a conifer species that typically colonises glacier forelands and screes. Methods Tree core samples collected for chronology development that spanned over a 119-year-long (1899–2017) period and the relationship of ring width with climatic data was analysed using correlation analysis. Results Radial growth in P. wallichiana was negatively correlated with mean temperature in March and over the pre-monsoon (March – May) seasonal average and it was positively correlated with monthly precipitation in March and September. Monthly standardised precipitation index (SPI) values indicated that overall the growth of P. wallichiana was mainly controlled by precipitation availability during the pre-monsoon season, particularly in March. Conclusion Moisture availability especially in spring is crucial for the radial growth of P. wallichiana. However, how this response varies throughout the elevational range of the species deserves further study to be able to make projections on the likely range expansion or contraction of the species in response to ongoing climate change.