TITLE:
Species-Specific Nutrient Resorption Strategies of Mangroves in Response to Salinity Stress in the Sundarbans, Bangladesh
AUTHORS:
Sanjoy Saha, Mohammad Mustafizur Rahman, Roksana Jahan, Mohammad Raqibul Hasan Siddique, Chameli Saha, Hossain Mahmood
KEYWORDS:
Adaptation, Excoecaria agallocha, Heritiera fomes, Nutrient, Resorption, Sundarbans
JOURNAL NAME:
Open Journal of Forestry,
Vol.15 No.4,
September
8,
2025
ABSTRACT: Mangroves adapt to saline and nutrient-poor environments through nutrient conservation strategies. This study evaluates nutrient resorption efficiencies (NRE) of nitrogen, phosphorus, and potassium in Heritiera fomes and Excoecaria agallocha from the Sundarbans Mangrove forest, Bangladesh. Soil and foliar samples were analyzed across seasons, nutrient resorption efficiency was calculated, and the relationship between the soil parameters (N, P, K, and Electrical Conductivity) and nutrient resorption efficiency of the studied species was also derived. Results showed that soil salinity was highest in the pre-monsoon season (5.03 ± 0.29 mS/cm). E. agallocha exhibited higher NRE across all nutrients, particularly nitrogen (63.15 ± 3.51% in the pre-monsoon), reflecting superior adaptability to saline conditions. Conversely, H. fomes showed lower NRE, especially for phosphorus (35.05 ± 5.33%), indicating limited conservation efficiency under salinity stress. A strong correlation between salinity and nitrogen resorption (r = 0.99 for E. agallocha) further highlights the role of salinity in nutrient dynamics. Weak correlations among soil nutrients and nutrient resorption efficiency for both studied species suggest nutrient resorption is relatively independent of soil nutrient levels for the study site. These findings underscore the superior adaptive capabilities of E. agallocha, enabling it to conserve nutrients more effectively under saline and nutrient-deficient conditions. With rising salinity in the Sundarbans, E. agallocha is likely to gain dominance, potentially reshaping the region’s mangrove species composition and posing challenges for conserving less resilient species like H. fomes. The foreseen shift in species dominance in the Sundarbans underscores the need for species-specific conservation and adaptive management strategies, with a focus on monitoring salinity-driven changes in composition and safeguarding vulnerable species like Heritiera fomes.