Phenology of Five Framework Tree Species on Doi Suthep

ABSTRACT: Climate change occurs for many reasons causing global temperature to rise affecting changes in abiotic factors such as air temperature, rainfall and relative humidity. These abiotic factors affect forest ecosystems and plant-growth patterns. This project compared phenological data between two time periods 24 years apart: 1995-1998 and 2019-2023. Phenological data were collected monthly from multiple individuals of five evergreen forest tree species in Doi Suthep-Pui National Park, northern Thailand, monthly from March 2022 to February 2023, using the crown density method. Air temperature differed significantly between the two time periods (P<0.05, t-test). Associated changes in reproductive patterns were found in 1) Garcinia mckeaniana (having no fruit phenophase in the later period), 2) Michelia babilonii and Ficus microcarpa (truncated fruit and flower phenophases in the later time period) and 3) Styrax benzoides (flowering earlier than in the past). Such phenology data may be useful to determine optimal seed-collection times to produce planting stock for forest ecosystem restoration projects.