The effect of climate on the phenology of six eucalypt species was observed during a period of two years under similar environmental conditions. High rainfall, temperature, and humidity were observed in the first year compared to the following year. High temperature, rainfall, and humidity had a significantly positive effect on the percent increase in height, dbh, early flowering, completion of flowering, and seed production however seed germination was negatively affected. Six eucalypt species flowered at different times of the year. E. microthica, E. camaldulensis, E. torriliana, and E. globulus flowered from January to April whereas E. kitsoniana and E. melanophloia flowered from November to December respectively. Generally, flowering was delayed by 13 – 15 days from the previous year. It was delayed in E. cammaldulensis, E. kitsoniana and E. microthica and was ended earlier in E. globulus, E. melanophloia, and E. torriliana respectively. A maximum percent increase in height was observed for E. microthica followed by E. cammaldulensis and E. kitsoniana. The lowest increase was observed in E. torriliana. Maximum dbh growth was observed in E. globulus (12.86%) and E. kitsoniana (12.16%) followed by E. cammaldulensis. The lowest was recorded for E. microthica (6.63%). Seed production was high in the year 2015 as compared to 2017. The highest seeds were produced by E. cammaldulensis (40 seeds per capsule) followed by E. kitsoniana and E. microthica, Seed production was negatively affected in E. globulus (28 seeds per capsule). The highest germination rate was observed for E. cammaldulensis (75%) and the lowest for E globulus (68%) and E. microlithic (67.5%). Our findings highlight that climate-driven shifts will likely occur because of changes in climate in the future and this may likely change the species' growth, behavior, response, pollinator behavior, and interspecific interaction and competition. The phenological response thus can be used for conservation, breeding, and sustained production of eucalypts in Pakistan.

Key words: Eucalyptus., Climate change., Phenology., Pollinator., Flowering., Seed Production., Seed Germination