Effect of climate warming on seedling growth and biomass accumulation of Acacia modestaand Olea ferrugineain a subtropical scrub forest of Pakistan

ABSTRACTThis study investigated the short-term impacts of projected climate warming on two dominant tree species of the Hayat-ul-Mir subtropical scrub forest of Pakistan. Seedlings of Acacia modestaand Olea ferrugineawere exposed to ambient (To) and warming temperature (To+ 2.3°C and To+ 4.5°C) with control (M15%) and elevated (M20%) soil moisture in plant growth chamber for 90 days. To+ 4.5°C induced detrimental effects on both species inhibiting seed germination and reducing their growth rate, biomass accumulation and allocation, however promoted development of root nodules (12 ± 4,0 nodules/root) in A. modesta. To+ 2.3°C with M20%was beneficial for O. ferrugineawith significant increase in stem height (4.8 ± 1.4 cm), elongated roots (31.2 ± 3.4 cm), branch development (9 ± 1.7), biomass accumulation (8.69 ± 0.4 g) and higher foliar nutrient concentration but for A. modestait only promoted root elongation (16.5 ± 1.3 cm) and biomass accumulation in stem (1.05 ± 0.1 g) and foliage (0.08 ± 0.001 g). A. modestagrew better under Towith significantly high germination and survival rate. A future 2.3°C warming could be ecologically significant to induce shifts in the structure and function of the Hayat-ul-Mir forest.