Application of land-use/land cover changes in monitoring and projecting forest biomass carbon loss in Pakistan

Abstract

Located at the foothills of the Himalayan Mountains, subtropical and moist temperate forests of Pakistan are very rich in flora and fauna. However, due to increased illegal and uncontrolled harvesting of wood, agricultural activities, and urbanization, these forests are fast disappearing. The recent expansion of human activities resulting illegal and uncontrolled harvesting, agricultural activities, and urbanization is a cause for concern. Using Landsat imagery, Markov Chain and Cellular Automata, this study focused on the quantitative assessment of spatiotemporal land use and land cover changes during 1998, 2008, 2018 and a simulation of 2028. In addition, a forest inventory survey of biomass and carbon sink were respectively calculated for these subtropical broad-leaved evergreen, subtropical chirpine and moist temperate forests. Results showed biomass was 560.56 ± 104.33 Mg ha−1, 350.95 ± 104.33 Mg ha−1 and 153.63 ± 104.33 Mg ha−1 in moist temperate, subtropical chirpine and subtropical broad-leaved forests respectively. Meanwhile, carbon was 313.94 ± 44.78 Mg C ha−1, 221.34 ± 44.78 Mg C ha−1 and 131.77 ± 44.78 Mg C ha−1 in moist temperate, subtropical chirpine and subtropical broad-leaved forests respectively. During the study period, land-use and land cover changes showed forest land changed from 40936.77 ha to 36709.23 ha, agricultural land from 4220.46 to 10374.64 ha, and built-up area from 1497.60 to 5395.12 ha. The average annual biomass and carbon loss were respectively 50.34 Gg ha−1yr−1 and 31.33 Gg C ha−1 yr−1. The information derived from this study could assist in the development of appropriate sustainable forest management policies in Pakistan. Keywords: Land use change, Biomass, Carbon, Himalayan mountains, Markov chain, Urbanization