Spatial analysis of forest cover and quality dynamics of Jalthal forest in the Jhapa district, Nepal

Efforts of community forest users show positive changes in forest cover and quality but there was limited study regarding this. Thus, this study was objectively conducted to assess dynamics of forest cover and quality between 1990 and 2021 in Jalthal Jhapa, Nepal. Supervised classification with a maximum likelihood algorithm was applied to classify forest cover to produce maps of 1990, 2005 and 2021. Forest quality change was assessed using Normalized Difference Vegetation Index (NDVI) and Soil Moisture Index (SVI). A total of 114.0 ha non-forest was converted into forest between 2005 and 2011. Overall accuracy of classified maps of 1990, 2005 and 2021 was 85.29%, 84.08% and 88.13%, respectively. Sparse forest was converted into dense forest by 0.06% between 1990 and 2021. Principal Component Analysis showed successful implementation of community forest program and control grazing were main factors positively affecting to increase forest cover and quality. Value of NDVI showed that high vegetation forest covers around 42.27% in 2021 and SMI was the highest. Kaiser-Meyer-Olk in (KMO) (0.474) and Bartlett Sphericity tests (p = 0.001) showed there was linear relationship between factors affecting forest cover and quality. This paper will be useful for academicians and policymakers to monitor forest.