Response of Radial Growth in Abies pindrow (Royle ex D.Don) Royle to Climate at Treeline Ecotone in the northwestern Himalaya

The growth response of Himalayan pindrow fir (Abies pindrow) was investigated using tree rings at the treeline ecotone in Hirpora Wildlife Sanctuary in the northwestern Himalaya. The ring-width chronology was built based on 73 increment cores extracted from 40 healthy trees. The measurements were standardized to remove non-climatic growth trends, especially the age-related growth trends. The persistence, because of the effect of the previous year climate on current year growth, in standardized site chronology was removed by auto-regressive modelling. For dendroclimatic analysis, static and moving correlations were computed between site chronology and monthly temperature and precipitation data from Srinagar meteorological station. The climate data was divided into two parts pre-and post-1950 because of varying degrees of increase in the annual climate data during these two time periods. The growth rings formed post-1950 were bigger than those formed prior to 1950. Also, the growth-climate relationships varied between the time periods. The trees responded strongly to monthly temperature in the second part of the twentieth century, while the positive response to growing season precipitation weakened in the recent decades. The moving correlation analyses showed periods of strong and weak climatic responses consistent with the results from static correlations in the two studied time periods. This study will help in understanding the growth responses of Himalayan conifers to climate and hence would also aid in better predicting their future growth in response to predicted climate warming.