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1.
Soil samples were collected and analyzed from 25 sites of three hilly regions (Rangamati, Banderban and Khagrachari) for an understanding of the impact of denudation and land use on soils in Chittagong Hill Tracts, Bangladesh. There were natural forests, bushy land, slashed sites, slashed and burnt sites, and the sites prepared for shifting cultivation, one year after shifting cultivation and two years after shifting cultivation. The soils were generally yellowish brown to reddish brown, sandy to sandy clay loam, strongly acid, and well to excessively drained on steep slopes with considerable variation among the sites and land use categories. Bulk density was the highest in sites of one year after shifting cultivation (1.52 g·cm-3) and the lowest in forested sites (1.38 g·cm-3). Water holding capacities were, however, statistically similar in all sites. Organic carbon varied from 0.54% (slashed and burnt sites) to 1.55% (forested sites) and total N ranged from 0.05% (shifting cultivation for one year) to 0.13% (forested sites). Available phosphorus (Bray & Kurtz-2 P) was the maximum in forested sites (12.32 mg·kg-1), and it did not differ significantly in other sites. Contents of available Ca, Mg and K were also higher in the bushy lands and forested sites than cleared and shifting cultivated sites. 相似文献
2.
在孟加拉国吉大港山区选择两块研究地,研究轮换种植对土壤中真菌和细菌群落的影响。两块研究地均包含轮换种植和本地社区管理的乡村森林,第一块研究地点选择在兰加马蒂地区,第二块研究地点选择在吉大港的班多尔班地区。在两个地点和不同用途的地块中,其表面土(0-10cm)和地表下土(10-20cm)的土壤质地不同,分别为砂壤和粘土。轮作地的土壤pH和含水量比乡村森林的低。研究结果表明:在兰加马蒂和班多尔班地区,大多数情况下,轮作地的表面土和地表下土壤中的真菌和细菌群落数量比乡村森林的低。在兰加马蒂和班多尔班地区的轮作地中,炭疽菌属(CoHetrotrichum)和镰孢菌属(Fusarium)真菌稀少,而两个地方的不同用途地块中均有细菌球菌属(Coccus),芽孢杆菌属(Bacillus)和链球菌属(Streptococcus)。在两个地方的不同用途地块中常见的真菌有曲霉属(Aspergillus)、根霉属(Rhizopus)、木霉属(Trichoderma)和青霉菌属(Penicillium)。在其它的土壤区系中,由于轮换种植导致土壤环境退化的程度还需要进一步的研究。 相似文献
3.
Rahman M. Motiur Yasushi Furukawa Isao Kawata Mohammed Mahabubur Rahman Mahbubul Alam 《Journal of Forest Research》2006,11(2):89-97
Empirical information regarding the role of homestead forests in household economy is essential in understanding the importance
of these resources. Identification of the factors that affect homestead forest production and understanding forest owners'
attitudes toward key forest management issues have great significance in making appropriate policy responses to manage these
resources on a sustainable basis. In Bangladesh, homestead forests are claimed to play an important economic role in rural
livelihoods, but no reliable quantitative information exists. This study was undertaken to investigate the role of homestead
forests in the household economy, examine if forest production and income vary across landholding size classes, to explore
the relationships of homestead forest production with species richness, education level, and household size, and to assess
the attitude of homestead forest owners toward key forest management issues. Results show that homestead forests contribute
15.9% of the household income and generate 51.4 man-days of employment per household per year. Production of homestead forests
significantly varies across landholding size classes. It was observed that forest production depends significantly on species
richness of homestead forests and the education level of forest owners. However, no such relationship was found between forest
production and household size. The study revealed that farming families depend more on forest income than nonfarming families.
Attitudes of forest owners toward key forest management issues differ significantly across landholding size classes. For example,
although the majority of the forest owners prefer fruit species to timber species, the percentage of respondents decreased
as the landholding size class increased, while the opposite trend was observed for timber species. The findings of this study
suggest that diversification of forests and extension of education amongst forest owners would improve forest production.
Furthermore, forest policy should address the concerns of the forest owners in different landholding classes and focus on
their specific requirements to enhance sustainable forest management. 相似文献
4.
Forest policy and sustainable forest management in Bangladesh: an analysis from national and international perspectives 总被引:2,自引:0,他引:2
This paper includes a review of international sustainable forestry development followed by an analysis of forest policies
in Bangladesh. There have been four different government forest policies in Bangladesh since 1894. The first two forest policies
(1894 and 1955) were exploitative in nature. Most of the regulatory documents were developed during the first two policy periods.
The third forest policy instituted in 1979 by the sovereign Bangladesh government had contradictory elements and mutually
inconsistent policy statements. It addressed for the first time forestry extension through mass motivation campaign. Current
forest policy formulated in 1994 has been considered to be the most elaborate policy in the history of the country. Under
this policy, participatory social forestry has been institutionalized in Bangladesh. The analysis shows that, although it
is possible to attain the stated policy targets, progress is slow and is blocked on several fronts. A number of identified
technical, managerial and logistical problems are hindering policy and program implementation. In addition, corruption contributes
to the observed problems. The real strength of Bangladesh forestry is locally based, participatory forestry, co-management
of protected areas and highly motivated people who increasingly recognize the need for a healthy forest ecosystem that will
provide future economic stability. Because it is the rich homestead forests of Bangladesh that generate the majority of commercial
forestry products, it is important that education continues at the grass-roots level. In addition, educated forestry and environment
professionals have been identified as the future driving forces towards better, and sustainable, forest management. Results
of this study make it clear that Bangladesh and other developing countries are not presently in a position to accept and adopt
internationally derived forest policies due to inadequate institutional support, political instability and poor governance.
Therefore, along with development of criteria and indicators of sustainable forest management and forest certification, international
policy scientists must consider institutional development, professional skill development, identification and adoption of
indigenous technology and long-term financial support in developing countries. Without these, all international processes,
policies and directives will be of little value and produce few substantive results. 相似文献
5.
Md. Motiur Rahman Yasushi Furukawa Isao Kawata Mohammed Mahabubur Rahman Mahbubul Alam 《Small-Scale Forestry》2005,4(3):359-376
This study examines the species composition, diversity and economic importance of homestead forests in the household economy
of central Bangladesh. The study documents 57 homestead forest species and their main usage in 90 households across three
villages of Gazipur Sadar Upazila. Homestead forests in Bangladesh comprise a mixture of fruit, timber and bamboo species.
While superficially homestead forestry appears unimportant in rural livelihoods, in reality the contribution is huge, both
as a source of food security and for other necessary household materials. A clear understanding of the physical characteristics
and economic role of homestead forests in rural livelihoods is vital for ensuring sustainable resource management. Income
and production of homestead forestry on a per hectare basis are found to vary widely between landholding size classes. Significant
relationships are identified between forest performance (production and income) and species richness and education level.
Homestead forestry appears to be a potential subsistence income generating land-use practice in the study area. The economic
scope of homestead forestry can be further enhanced provided the appropriate species composition of the forest is achieved
and the education of forest owners is ensured through targeted management and policy interventions. 相似文献
6.
Anja Nygren Celeste Lacuna-Richman Kati Keinänen Loreta Alsa 《Small-Scale Forestry》2006,5(2):249-269
Discussion of the role of non-timber forest products (NTFPs) in efforts to reconcile the objectives of forest conservation
and rural development has often been hampered by limited understanding of the complexity of the factors that affect the contribution
of NTFPs to local livelihoods. By drawing upon two case studies where NTFPs play an important role - the municipality of Lepaterique
in Honduras and Palawan Island in the Philippines - this study emphasizes that an ideal extractive system should be based
on a mix of products to enable sustainable harvesting throughout the year. The study also demonstrates that considerable attention
needs to be paid to the socio-cultural heterogeneity of resource users, and to the value chain structure, access and control
over resources and political transparency that affect the opportunities for local people to benefit from NTFP extraction. 相似文献