Impact of climatic patterns on phenophase and growth of multi-purpose trees of north-western mid-Himalayan ecosystem

Abstract

Earth's mean air temperature is increasing at an accelerating rate, and forest tree species are sensitive to this changing climate. However, tree species react variably to changing climates across different geographical ranges. Thus, eleven multi-purpose tree species (MPTs), Albizia stipulata, Bauhinia variegata, Celtis australis, Dalbergia sissoo, Gmelina arborea, Grewia optiva, Melia azedarach, Morus alba, Robinia pseudoacacia, Sapindus mukorossi and Toona ciliata, of the mid-hill zone of the northwestern Himalayas were selected to analyze the impact of climatic patterns on their phenological events over two decades (1999–2017). The results indicated that phenological advancement (in days) was more pronounced from 1999 to 2006 than from 2006 to 2017. Specifically, leaf emergence phase advancement ranged from 5 (R. pseudoacacia) to 38 days (M. alba). However, advancement in the flower initiation phase for MPTs was not as prominent. The growth period of M. azedarach was prolonged the most (60 days), followed by those of B. variegata (56 days), D. sissoo (51 days), T. ciliata (48 days), S. mukorossi (46 days), R. pseudoacacia (44 days), G. optiva (41 days), G. arborea (20 days), A. stipulate (15 days), M. alba (10 days) and C. australis (7 days). Increasing growing season duration and rate have implications on future composition, nutrient cycling and carbon sequestration of agro-ecosystems of the mid-hill zone of the north western Himalayas.