Ecological Study of Aboveground Biomass and Plant Species Diversity in Complex Agroforestry Sites, Lampung, Indonesia

Abstract

Abstract It is necessary to estimate the total carbon of forest or agroforest biomass using satellite remote sensing technology since the areas of Indonesian forests and agroforest are very large. However, ground truthing a large area would be time consuming and expensive; and the results might be affected by changes in the vegetation structure over the duration of the survey. Moreover, this method was also effective in monitoring changes in biomass and carbon by year. This study was therefore critical due to the lack of similar studies in Indonesia, especially on Sumatera Island. This study has the puspose to estimate the total biomass and biodiversity value in Damar agroforest; and investigate the relationship between the carbon stock in agroforest biomass and the pixel value, and continued mapping the carbon. In addition, simple linear regression and multiple linear regression were applied to analyse the single spectral band ratios of 1 to 5 and 7; and it also applied the 10 vegetation indices such as Simple Ratio 4/3, NDVI, SAVI, Brightness, Greenness, Wetness, TNDVI, ND 73, Simple Ratio 7/3, and Ratio 327 as a biomass predictor. The results have found that the dominating species (51 %) was Shorea javanica belonging to the family of Dipterocarpaceae. In addition, 73 species belonging to 35 families were identified. Biodiversity was identified to be moderately stable and the distribution of species abundance falls in the moderate category. Thus 70 % of Damar agroforest areas might be dominated by one or more species. The significant model was successful in finding in spectral reflectance at band 7. In addition, the model based on simple linear regression produced of R2 = 0.44; F-stat. = 14.88 > F crit. = 4.38, p-value = 0.001, df = 1, 19; and the model has the lowest value of RMSE = 52.84. This model was chosen as the ideal model to predict a carbon content in Damar agroforest with equation Y = 267.83 – 1625.5 band 7. The average carbon content was estimated to be 130.19 Mg C/ha, such carbon content was nearly equal to that of Dipterocarp forest. It is therefore important to maintain the Damar agroforest ecosystem services with high biodiversity as well as natural forest; furthermore, it is also a preferable site for carbon trading.