Effects of water and nutrient additions on the timing and duration of phenological stages of resprouting Terminalia sericea

• Water and nutrient additions had significant effects on resprouting tree phenological stages.
• Leaf discolouration occurred earlier in unsupplemented trees compared to supplemented trees.
• Fruit presence was mainly in supplemented resprouting trees, a year after cutting.

There is limited information about the factors that affect phenology of coppicing trees. This study examined the effects of water and nutrient additions on the phenology of coppicing Terminalia sericea trees in a semi-arid savanna in South Africa. Cut trees were exposed to different levels of water and nutrient (nitrogen and phosphorus) supplementations over a period of two years. Phenological stages monitored fortnightly included leaf bud presence, leaf presence and fruit production. Leaf presence followed a similar distribution to bud presence, peaking during the wet season (November–April), with the low water and high nutrient additions having the highest significant effect. Change in leaf color from the typical silvery green to yellow was delayed to later in the wet season, while higher leaf numbers were recorded during the wet seasons for trees supplemented with water and nutrients. Results indicate that the increase in water and nutrient availability has direct consequences for extending the growing season of resprouting trees. This extension has positive effects on increasing the photosynthetically active period, thus potentially increasing the carbon gain and growth of trees. Although generally low throughout the study in all treatments, fruit presence was mainly in supplemented trees.