In recent times, environmental stewardship of mangroves has provided the impetus to protect and restore these ecosystems for their inherent ability to protect coastal regions from climate change, sequester carbon dioxide as rich blue carbon, and support human well-being through a multitude of ecosystem services. Participatory stakeholder assessment, as a part of the present study, integrated local stakeholder perspectives in assessing drivers of mangrove loss in Bhitarkanika and Mahanadi delta, Odisha, providing empirical evidence through a mixed-method approach. The use of a Likert scale provided the methodology to develop a single composite variable as the best measure of central tendency. In total, 27.5% of the respondents were locals and were living close to the study area for generations, whereas the other 72.5% represented researchers, academics, and forest department officials. Stakeholder responses at the ground level indicated that Bhitarkanika and Mahanadi delta were facing increased frequency of extreme climatic events followed, by aquaculture and other land-use changes, which can be considered potential drivers causing mangrove loss. Co-development of future scenarios by integrating concerns of all the stakeholders emerged as a potential solution to effectively address the trade-offs arising from local anthropogenic interferences, as well as large-scale developmental activities. This study highlights the need for convergence of multi-disciplinary knowledge from diverse stakeholder groups, including traditional and indigenous knowledge, for the purpose of developing accurate plausible alternative scenarios. Interactive governance and incentivization approaches, along with alternative livelihood opportunities, are proposed as the means to improve conservation and restoration in the region based on the present study. Understanding of the coupled socio-ecological system and its relevance is found to be critical to improve bi-directional linkages of ecosystem health and human well-being.

Background: The mangrove ecosystem has the highest carbon sink potential which significantly contributes to bringing carbon neutrality. Understanding the carbon stock dynamics along the age of forest stands in the mangrove forest ecosystem is of significance for managing the forests and their carbon accumulation. This study aimed to estimate the forest structural attributes, biomass and total ecosystem carbon stock (TECS) of old natural (age > 50 years) and young planted (age ~ 20 years) mangrove forest stands at Bichitrapur Mangrove Reserve Forest in eastern coast of India. We also attempted to understand the interrelationship of structural attributes, biomass and soil properties in the mangrove forests. To achieve the results, twenty random plots were established (size: 20 m × 25 m) and suitable allometric equations along with species-specific wood density values were used to estimate the biomass and carbon stock. Results: Altogether, 29 plant species (18 exclusive and 11 associate species) were recorded. The mean total biomass (± SE) and soil organic carbon (at 30 cm depth) were 165.31 ± 20.89 t ha⁻¹ and 40.20 ± 1.24 t C ha⁻¹ for young stands, and 586.12 ± 56.74 t ha⁻¹ and 49.68 ± 2.39 t C ha⁻¹ for old stands, respectively. Among mangrove species, Avicennia marina contributed the highest vegetation biomass in both forest stands (59.72 t ha⁻¹ and 262.28 t ha⁻¹ in young and old stands, respectively), followed by Avicennia officinalis (35.05 t ha⁻¹) and Sonneratia apetala (26.09 t ha⁻¹) in young stand and Avicennia alba (169.28 t ha⁻¹) and Avicennia officinalis (115.58 t ha⁻¹) in old stand. The mean TECS was 235.62 ± 27.34 t C ha⁻¹. The contribution of vegetation and soil to TECS was 63% and 37% in the young stand, whereas in the old stand it was 83% and 17%, respectively. The correlation analyses revealed that mean stand height (r = 0.87), basal area (r = 0.99), soil nitrogen (r = 0.76), potassium (r = 0.78), and carbon (r = 0.80) were significantly positively correlated with total biomass at p < 0.01. Conclusions: Our results demonstrate that old mangrove forest stands store substantially high carbon stock than young planted forest stands, implying the role of forest age in determining the carbon storage potential of mangrove ecosystems.

Panda M, Samal RN, Bhatta KS, Lenka S, Rout J, Patra HK, Nanda S. 2018. Diversity and distribution of vascular macrophytes in Ansupa Lake, Odisha, India. Bonorowo Wetlands 1: 1-12. Macrophytes are indispensable component of any wetlands. They are the base of the trophic structure and variously affect function of aquatic ecosystem. Large invasion of macrophytes enforced for present studies in Ansupa Lake, the largest freshwater lake of the state Odisha (India) to identify the causative plant species. Regular field inspection, quadratic sampling and specimen collections were carried to identify the present macrophytes of the lake and their quantitative aspects like frequency of occurrences, abundance, values of diversity indices, adaptation and growth forms and species distribution etc. A total of 244 macrophyte species were identified that includes 182 semi-aquatic and 62 obligatory aquatic macrophytes. The latter group had 35% submerged, 15% free floating, 31% rooted floating and 19% marshy plant species. The comparison of growth form showed 64% annuals and remaining 36% perennial plants. The diversity indices resulted, Simpson complement index-0.561, Shannon-Weiner index-1.367, Species richness index 3.079 and Species evenness index-0.156. The study showed that the lake provides suitable habitats for existence of a diverse group of macrophytes but still due to large invasion of few species has threatened the lake which needs to be managed properly to restore the health of this natural resource for the benefit of mankind.