Statistical relationship between leaf litter and tree growth characteristics of Tectona grandis species

Forest productivity relies on the quantity and quality of litter as this influences nutrient cycling in the ecosystem. Many studies have been carried out on litter fall, but few attempts has been made to relate litter fall nutrient content with tree growth variables The aim of this work was to investigate basic relationships between the leaf litter nutrient content of Tectona grandis and tree growth characteristics. The study was done at the arboretum of the Department of Forestry and Wildlife Management, University of Port Harcourt, Rivers State, Nigeria. Data were collected from four (4) randomly selected 20m × 20m (0.04ha) plots. Within each plots, four (4) litter traps at 8m apart was set at random to collect litter on a weekly basis, while tree growth variables were measured on trees around the trap. The collected litter was put into zip-lock bags and taken to the laboratory for nutrient content analysis. Nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sodium (Na), magnesium (Mg) content and pH were included in this. The result shows that the average weekly leaf litter collected from the trap was 11.8g. In terms of average nutrient content, Nitrogen had the highest average at 1.8, while Sodium (Na) had the lowest value at 0.14. Among the tree growth variables, only height had a positive correlation with litter collected. The results also show that Nitrogen micronutrient content was related to the amount of litter collected (0.536). In addition, all the exchangeable base analysed in the study were also related to the amount of litter collected. Conclusively, the amount of litter produced is a major indicator of primary productivity because as litter quantity increases, available nutrient content for plant growth also increases, hence, having influence on tree height