Md. Enamul Kabir

Floristics and structure of southwestern Bangladesh homegardens

Homegardening is a traditional agroforestry practice in Bangladesh. Diverse species composition in a complex structure is a characteristic feature of Bangladesh homegardens. This study investigated the floristic and structural characteristics of homegardens from 402 randomly selected households in southwestern Bangladesh. A total of 419 species in 109 families were recorded. Fifty-nine per cent of all species were native to the Indian Subcontinent, including six IUCN Red-Listed for Bangladesh. Seventy-five per cent of all species were planted. Trees and herbs predominated and accounted for about 71% of all the identified species. The median homegarden of 800 m2 contained 34 species and 107 individual trees and shrubs. The recorded species were used for nine different purposes. In general, native species were more commonly used for all purposes except food, commerce, and fibre. The vertical architecture of the homegarden was complex. Common species were consistent with the general floristic profile reported from other tropical homegardens. Homegardens provided year-round subsistence and economic benefits from balanced adoption of multiple-use plants in different strata on limited homestead space. The results suggest considerable potential for the establishment and development of homegardening systems for the sustainable supply of subsistence livelihoods, while contributing to biodiversity conservation.

Home Gardening for Tropical Biodiversity Conservation

Human-dominated ecosystems are the dominant feature of Earth’s landscape (Vitousek et al. 1997; Kareiva et al. 2007). In the tropics, habitat degradation and forest conversion pose a significant risk of widespread terrestrial species extinction (Sodhi et al. 2004). Our ability to conserve biodiversity in human-dominated systems increasingly requires research into mechanisms that can maintain species in fragmented and degraded landscapes. A large body of research has demonstrated that the conservation of tropical biodiversity in degraded tropical landscapes can be assisted through the management of diverse agroforestry systems (Bhagwat et al. 2008; Gardner et al. 2009). Historically, the bulk of research attention has been given to agroforestry systems such as swidden agriculture and mixed cropping. Home gardening, the agroforestry practice of planting a mixed patch of livelihood-oriented perennial and annual species within a clearly bounded area near the homestead (Fernandes & Nair 1986), has received little quantitative research attention as a possible biodiversity conservation tool. We searched on the Web of Science and Google Scholar for literature since 1980 with the terms homegarden∗ and home garden∗ in the title, cross-referenced from the reference lists of collected publications, and selected studies from tropical locations. We found a modest 156 peerreviewed journal articles, book chapters, and Internetlisted gray literature. The studies ranged across urban, suburban, and rural settings in more than 30 tropical countries. Of the 156 papers, 74% contained partial or complete information on plant composition and structure, but only 13% collected sufficient quantitative botanical information to make clear conservation recommendations. Only 3% of the studies discussed wildlife in home gardens. These are surprisingly low figures considering the prevalence of home gardens in the tropics and their importance for livelihood supplementation in urban and

Rural settlements dynamics and the prospects of densification strategy in rural Bangladesh

Given the year on year decrease of rural farmland and various forms of land degradation through the intrusion of non-farm land uses, the government of Bangladesh has drafted the agrarian reform strategies, primarily to protect the agricultural land from encroachment, conversion, and indiscriminate use. The draft Agricultural Land Protection and Land Use Bill since its inception in 2011 is facing serious uncertainties of implementation due to its borrowed nature from the developed contexts and inadequacy to recognize the local complexities. With a particular focus on the densification component of the draft bill, a semester-long design studio was conducted in consultation with the existing villagers to explore the practicability of the draft bill in the villages of Tetultala and Chhoygharia in the south-western coastal Bangladesh. The findings from the two villages hint that in Bangladesh, the unique and evolving nature of rural settlements dynamics that are disintegrating the rural society from farming practices and the farmland, thereby, unsettling the traditional village-morphology. The settlements dynamics vary from those of the western context; hence, there is an emerging need to build locally situated knowledge towards a feasible rural land reform.

Actor-Centered Interest Power Analysis of Participatory Biodiversity Conservation Policy Program in and Around the Bangladeshi Sundarbans

The polders and the adjacent area are the property of the Bangladesh Water Development Board. These polders have a significant role in the socio-environmental situation of the southwestern region of Bangladesh. The presence of the Sundarbans on opposite bank of the rivers makes this situation more important in terms of biodiversity context. Additionally, it is very common to find landless people as settlers along the polders in these particular regions. Although the land belongs to the state, these areas are used as common-pool resources. Hence multiple level stakeholders/actors are involved in the management of the polder areas particularly in respect of plantations. As GIZ has taken a pilot project for the conservation of biodiversity along the polder area in a participatory way, it is imperative to have a stakeholder/actor analysis in terms of interest and power in the pilot area. This study has done the complete network analysis in seven unions (Suterkhali, Rayenda, Southkhali, Ramjannagar, Munshiganj, Burigoalini, and Shyamnagar) of three upazilas (Dacope, Sarankhola, and Shyamnagar). The study found that the local government, local politicians, local beneficiaries, local elites, local NGOs, and upazila administrations are the irreplaceable stakeholders at local level. Water development board and forest administration are the two other irreplaceable actor at national level. These actors dominate the interest power network of participatory biodiversity policy program in and around Bangladeshi Sundarbans. Additionally the present co-management strategy of Bangladesh also advocates in favor of the administration-dominated institutions.

Ecology of Kandelia obovata (S., L.) Yong: A Fast-Growing Mangrove in Okinawa, Japan

Mangroves are the association of woody trees and shrubs in the intertidal zone of tropical and subtropical coasts. Mangroves play a significant role in carbon sequestration, as they store large amount of organic matter in their substrates and roots. This chapter focuses on the ecology of biomass production and carbon trapping potentials in the pioneer mangrove Kandelia obovata in the light of canopy radiation balance, intraspecific competition, allometric relationships, biomass allocation, net primary production and carbon sequestration. K. obovata shows a low light extinction coefficient of leaves (0.43) suggesting a shade-intolerant nature of the species. In the young stage, trees form smaller clumps that hinder each other in growth but do not lead to a significant size class differentiation. However, after ca. two decades, the self-thinning starts and a mutual inhibition of growth and size differentiation is observed. As a stand grows older, the spatial pattern of individuals becomes more regular from a clustered pattern. In the allometric equations for estimating the above-ground phytomass, the parameter D0.12H (D0.1, diameter at one-tenth of tree height H) instead of D2H (D = diameter at 1.3 m height) or D performs better. At the stand age of 10 years, the species is capable of yielding an above-ground biomass of 80.5 Mg ha−1 and belowground biomass of 71.5 Mg ha−1. The above-ground net primary production estimates 29.9–32.1 Mg ha−1 year−1, which is ca. 2.8–3.0 times of annual litter fall. The low leaf longevity (9.3 months) and high growth efficiency (5.35–5.98 Mg ha−1 year−1) make it a highly productive mangrove species. The carbon stock in the above ground (35.1 Mg ha−1) is 1.3 times in the belowground (26.9 Mg ha−1). Soil C stock (57.3 Mg ha−1) is closer to the vegetation C stock (62.0 Mg ha−1), indicating that the mangrove stores a large amount of carbon in the soil. The growth efficiency and carbon trapping mechanism of the mangrove K. obovata make it a highly suitable species in the study region Okinawa Island. New plantations can be raised in the intertidal zones of Okinawa Island using K. obovata, which would in turn contribute towards carbon sequestration and climate change mitigation.

Protected Areas for Climate Change Mitigation and Livelihood Option: A Case Study of the Bangladesh Sundarbans Mangrove Forest

Carbon sequestration is an important REDD+ strategy to global climate change mitigation and adaptation, biodiversity protection, and livelihood generation. This study investigated the floristic composition, ecosystem level carbon sequestration, and relation between forest composition and carbon pools in three protected areas (PAs) of the Bangladesh Sundarbans Mangrove Forest. Systematic grid sampling method was employed to collect data from a total of 29 cluster plots composed of five nested circular (10 m radius) subplots of equal size (1570.50 m2) each during two forest inventories (in 1997 and 2010). Mean diversity, evenness, and richness of all recorded species were respectively 1.21, 0.37, and 0.59. No significant difference was observed between species diversity, evenness, and richness across three PAs. The mean ecosystem level carbon stock was measured 218.72 Mg ha−1. The ecosystem level carbon stocks were found significantly different across the three PAs. The Sundarbans East Wildlife Sanctuary contained the highest amount of carbon (299.49 Mg ha−1) followed by the Sundarbans South Wildlife Sanctuary and the Sundarbans West Wildlife Sanctuary. There was no significant relationship with carbon (above- and belowground) content with species diversity, evenness, and richness. Shrub-herb carbon stocks showed significant negative correlation with species diversity and evenness. We found significant variation in ecosystem level carbon sequestration across the three wildlife sanctuaries. The mean yearly ecosystem level carbon sequestration rate was 3.93 Mg ha−1 equivalent to 14.44 Mg CO2 ha−1. Thus, the three PAs with its total land cover of 90,747 ha (22 % of the entire mangrove Sundarbans) have been sequestering 1.31 million ton CO2 per year which can earn 19.65 million USD yearly (@15 USD/t CO2). Thus, the Sundarbans Mangrove Forest has enormous potential to address global climate change mitigation, biodiversity conservation, and perhaps more importantly livelihoods to millions of people through participating in Payment for Environmental Services (PES) of the REDD+ financial mechanism.