The consequence of increasing tree diversity was reducing tree basal area at across different management of agroforestry system of Bangsri Wathershed

Abstract

The Planting more trees in terrestrial ecosystem had provided on the increasing on many ecosystem services including carbon storage, water supply and soil cover. The relationship between the impact on increasing tree density on tree diversity across various land use type are limited. Using a survey and collecting field measurement within the plot in the size of (100 m × 20 m), we investigated the effect of different type land use on tree diversity, basal area, and species composition at Bangsri Watershed-East Java, comparing different agroforestry system to various young to old production forest of Mahogany (Sweitenia mahogany), Pines (Pinus merkusii) and Rekisi (Magnolia × alba (D.C.). The result showed that seedling population under complex agroforestry system was almost twice (389 individuha-1) higher that those simple agroforestry system or production forest. Young Mahogany (4-5 years) provide the highest number of poles, whilst old Mahogany and Pines production forest (30-40 years) were contributed the greatest tree population at (500 – 600) individuha-1 providing the highest value of basal area since the average of those tree diameter within the size of (25-40 cm). Tree population of complex agroforestry system were lower 50% than production forest. However, diversity indices (H’) of sapling, pole and tree under complex agroforestry system were between 1 to 2.5, while the others plot were<1, except for seedling diversity. In particular the increasing of tree population impact of greater basal area but however it reduced the diversity of, seedling, sapling, pole and tree as the consequences of the implementation of different tree and land management.