Forecasting Phenological Shifts in Forest Tree Species using Herbarium Records from the Kumaun Himalaya, India

Zoya Shah1*, Dhani Arya2

1,2 Department of Botany, Soban Singh Jeena University, Almora, Uttarakhand, India-263601

Abstract:Climate change is shifting phenological timing, i.e., flowering, in forest ecosystems. The research here investigates phenological change in flowering in eight ecologically different tree species of the forest in the Kumaun Himalaya, i.e., Acacia dealbata, Pyrus pashia, Quercus floribunda, Quercus leucotrichophora, Rhododendron arboreum, Cedrus deodara, Pinus roxburghii, and Pinus wallichiana. Following Generalized Additive Models (GAMs), herbarium records (1985–2020) and recent field observations (2015–2021) were used to estimate phenological change. Advanced shift in the date of flowering onset, from 13 to 42 days earlier, owing mainly to rising temperatures, is revealed by the findings. The phenological changes have ecological and socio-economic implications, e.g., reduced fruit productivity in P. pashia, which can result in enhanced wildlife crop-raiding. The findings underscore the value of the integration of historical herbarium observations with recent observations in monitoring phenological responses to climate change, and the necessity of longer-term, region-specific monitoring protocols.Keywords: Phenological shifts, Climate change impacts, Herbarium records, Flowering period shifts, Kumaun Himalaya.