Species diversity, change in forest cover and area of the Sundarbans, Bangladesh

Abstract

The phytosociological analysis, species diversity and types, fidelity, presence, constancy, Sørensen similarity index and changes in forest cover, land and water areas since 1972 were analyzed. Forty six species were recorded both in quadrats and growing outside which belong to 26 families and 41 genera, 19 were distinguished as true mangrove species and the rest were mangrove associates. Leguminosae and Rhizophoraceae were the dominant families represented by 5 spp. each. Three species were found to be invasive, namely Blumea lacera (Burm. F.) DC., Catharanthus roseus (L.) G. Don., Wedelia chinensis (Osbeck) Merr. The maximum importance value index was found in Heritiera fomes Buch.-Ham (48.08). The overall species diversity (H) of SMF was found 3.81, species richness (d) was 9.10 and evenness (e) was 0.47. The forest area was 385,237 ha in 2015. The satellite images showed that the forest and water area of SMF decreased gradually till 2015 in comparison to 1972. The bare land of Sundarbans showed a significantly increasing trend till 2015 since 1972.

Carbon pool and respiration of rhizosphere soils of different mangrove plant species in bangladesh sundarbans

“…Both Rs and SOC serve as critical indicators of soil quality and fertility (Moharana et al 2012, Propa et al 2021. Despite extensive research on the coastal zones and Bangladesh Sundarbans, focusing on topics such as species diversity (Ahmed et al 2018), phytoplankton diversity and water quality (Ahmed et al 2019), edaphic characteristics and contamination level (Ataullah et al 2017(Ataullah et al , 2018, carbon stock in various plant species (Ahmed et al 2021), forest cover and community structure changes (Ahmed et al 2011(Ahmed et al , 2018, anatomical adaptation of mangrove species (Rashid et al 2020), there exists a noticeable gap in the study of SOC and Rs of the rhizosphere soil of this mangrove forests. This gap is particularly significant given their relevance in the context of global climate change.…”

Leaf anatomical adaptation of eighteen mangrove plant species from the Sundarbans in Bangladesh

“…The Sundarbans was originally extended about 40,000 sq, km but with continual agricultural and anthropogenic invasion the forest area reduced to a greater extent at around 16,000 sq km by 1930s (Blasco 1977). The Sundarbans is now restricted to around 10,000 sq km, stretching between the Baleshwar river, Bangladesh (about 60%) and the Hooghly river, India (about 40%) (Ahmed et al 2018). Different saline zones, namely oligohaline, mesohaline and polyhaline occurs within SMF (Nazrul-Islam 2003) which is arbitrary depending on the seasons.…”