PJB-2023-1526
Dendrochronological investigations reveal declining growth rate of Pinus roxburghii Sarg. populations from 1840 to 2017 in Kashmir Himalayas
Muhammad Sohail, Hamayun Shaheen, Raja Waqar Ahmed Khan, Muhammad Faheem Siddiqui and Moin-Ud-Din Ahmad
Abstract
Pinus roxburghii Sarg. is a keystone gymnosperm tree of Western Himalayan subtropical forests of Kashmir region. It is a good choice for dendrochronological investigations as its core samples have potential to reflect changes in climatic pattern its growth rings. The present dendrochronological study was aimed to investigate the trends in growth as well as structural attributes of P. roxburghii. A cross dated tree-ring chronology for 177 years period was developed from 1840 to 2017. The average growth rate of P. roxburghii was calculated as 0.89 ± 0.02 year/cm. Tree Ring Width index revealed that P. roxburghii growth rate decreased from 1840-1880 AD whereas the growth rate significantly increased during the period 1890-1920 followed by a gradual decline afterwards till 2017. A total of 101 years were marked with slow growth whereas higher growth was found in 75 years. The decline in growth rate is synchronized with the disturbance stimuli and socioeconomic transformations in the study area during the last century. The average DBH was recorded to be 87.87 cm, ranging from a minimum of 70.5 cm to a maximum of 108.5 cm whereas the average core length was recorded as 21.2 cm. The average age of P. roxburghii trees was calculated to be 123.06 years with the oldest tree specimen of 245 years. The decline in the Pinus growth rate appears to be synchronized with climate change induced increasing temperatures during the last century. It is recommended that the tree rings chronologies should be constructed for further keystone taxa to reconstruct past climatic history in this region
To Cite this article:
Sohail, M., H. Shaheen, R.W.A. Khan, M.F. Siddiqui and M.U. Ahmad. 2023. Dendrochronological investigations reveal declining growth rate of Pinus roxburghii Sarg. populations from 1840 to 2017 in Kashmir Himalayas. Pak. J. Bot., 55(3): DOI: http://dx.doi.org/10.30848/PJB2023-3(30)
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