SPATIO-TEMPORAL ANALYSIS OF MANGROVES AND CARBON STOCK ASSESSMENT IN BLUE CARBON ECOSYSTEM (KETI BANDAR), KARACHI, PAKISTAN

Abstract

Mangroves ecosystem are wetlands having diverse assemblage of trees and shrubs which is located in tropical and subtropical regions between approximately 30°N and 30°S latitude. Mangroves are well-known for their numerous ecosystem services, including storing a globally significant carbon pool. There is an increasing interest in the inclusion of mangroves in national climate change mitigation and adaptation plans in developing nations. Large-scale carbon mapping is needed to support the UNFCCC program to reduce deforestation and forest degradation (REDD). Managers of forested land can potentially increase their carbon credits via detailed monitoring of forest cover, loss and gain (hectares), and periodic estimates of changes in forest carbon density (tons/ha). Satellites provide an opportunity to monitor changes in forest carbon caused by forest degradation and deforestation, but only after have detailed inventories of forest land and carbon stock assessment. This study is conducted in the Keti Bandar area located at about 200 km (125 miles) south-east of Karachi in Thatta district of Sindh province, Pakistan. Spatio-temporal analysis and carbon stock assessment were done for the mangroves. Satellite observations have shown that mangrove forest cover has increased from 37300 hectares in 1988 to 80100 hectares (in 2020 with an increase of 42800 hectares (7.1%) during the past thirty years. The carbon stock assessment result shows Avicenna marina and R. apiculata were the only species found in the study area. Tree density ranged from 380 to 1100 trees/ha. At study site the largest tree was an Avicenna marina tree with DBH of 35.5 cm while the mean DBH of the trees in the study area was 7.5cm. AGB (above ground biomass) and BGB (below ground biomass) of the mangroves species in the study area was calculated as 7.76 t/ha and 1.94 t/ha. The overall amount 5.88 ton/ha of soil carbon of the mangroves area was measured The total carbon stock of the mangrove in 1988 was 0.3 million tons in total area. The Carbon stock increased to 0.5 million tons in the year 1988-1998, then decreased to 0.4 million tons in the year 1998-2008 and then again increased to 0.6 million tons in 2020.