Effects of shoot mortality on the early development of Afzelia quanzensis seedlings.

This study investigated the occurrence of shoot mortality and its effects on the development of seedlings of the economically valuable timber tree Afzelia quanzensis under natural conditions in the absence of fire at Lusaka, Zambia. Mean seed germination was 86 and 99% in the laboratory and field, respectively. Seedling emergence occurred 2–4 weeks after planting in the laboratory compared to 3–10 weeks in the field. Seedling mortality during the first year was low (12%), but shoots of 60% of the surviving seedlings died back to ground level, apparently because of water stress. Maximum leaf production was in the middle of the rainy season, but leaf production and shoot growth cease before it ended. Root growth continued for 2–3 months after cessation of shoot growth. Seedlings whose shoots died back during the first year had much lower shoot and root biomass and fewer leaves at the end of the second growing season than seedlings without shoot die-back. [ABSTRACT FROM AUTHOR]