SOIL CHARACTERISTICS AND CARBON SEQUESTRATION POTENTIALS OF VEGETATION IN DEGRADED HILLS OF CHITTAGONG,BANGLADESH

The impacts of tree and horticultural plantations, and grassland on soil characteristics in the degraded hills of Chittagong District, Bangladesh are reported on this paper. The carbon sequestration potential and the present value of carbon revenue flow were also estimated for the degraded hills of Chittagong using A. auriculiformis plantations for the purpose. The results showed that the change of land use from degraded hill to vegetation cover had altered the physico‐chemical characteristics of soil in the study area. The organic carbon concentration and storage under vegetated land uses were significantly (p < 0·05) higher than those in the degraded hill areas. The results also showed that about 17 million megagram carbon (MgC) could be sequestered in the degraded hill areas of Chittagong District by planting A. auriculiformis trees in a 15‐year rotation. The present value of revenue flow generated by this sequestration at the current international market carbon price and assuming a realistic market interest rate could be as high as US$ 326 million. The net present value of the revenue stream is expected to be positive. Copyright © 2011 John Wiley & Sons, Ltd.     

Copper in soils,plants, and ruminant animal nutrition with special reference to sub‐Saharan Africa

Copper (Cu) is not only essential as a component of a number of different plant enzymes and necessary for the activity of several specific enzymes, it is also an important constituent of blood proteins necessary for the normal physiological functioning of the animal body. The role of Cu in agricultural production has been documented by several authors and these reviews mainly relate to work in the temperate regions.

This review has attempted to extract all available information in sub‐Saharan Africa (SSA) on the role of Cu on the soil, plant and animal systems. It discusses the content of Cu in the soil and plant, its role and biochemistry and methods of analysis with special reference to research in SSA. The need to maintain adequate levels of Cu levels in the soil and forage crops for ruminant animal consumption is emphasised. Factors such as age, physiological state, breed, dry matter intake and source of Cu which influence dietary Cu requirements of ruminant animals were reviewed. Deficiency and toxicity cases of Cu in animals have been diagnosed in many SSA countries. Although there are several ways of correcting Cu deficiency and toxicity problems, success depends on the ability to identify the underlying causes. The interaction of Cu with other minerals, in particular molybdenum (Mo) and sulfur (S), is an important factor determining whether a deficiency or toxicity is “simple”; or “conditioned”;.     

孟加拉羯布罗香(Dipterocarpus turbinatus Gaertn.F)外生侵染菌根的水平分布(英文)

本文论述了孟加拉国吉大港大学校园里,不同年龄(5、10、20年)的羯布罗香(DipterocarpusturbinatusGaertn.F)人工林内,距树木基部不同距离(1、2、3、4米)处,外生侵染菌根的水平分布状况。在山的3个部位(顶部、中部和下部)对各人工林外生侵染菌根的侵染进行了测定。在不同水平分布距离处的树下采集了1000cm3的根际土壤样本,不同距离和山高处的外生侵染菌根浸染率差异显著。在5年和10年林龄的人工林内,浸染率随着距树的距离的增加而快速下降,而在20年林龄的人工林内,浸染率随着距树基部距离的增加而急剧增加。山下部20年生人工林内距树4m处的浸染率最高(81.3%),山顶部5年生人工林内距树4m处的浸染率最低(55.33%)。     

Antibacterial compounds from the seeds of Psoralea corylifolia

Psoralidin, bakuchicin, psoralin and angelicin, isolated from the seeds of Psoralea corylifolia, showed significant antibacterial activities against a number of Gram (+) and Gram (-) bacteria.     

Adsorption and desorption of sulphate in some soils of the West Indies

Adsorption of sulphate was studied on eight West Indian soils. Adsorption was dependent on concentration for all the soils studied. At low concentrations of dissolved sulphate, the amount adsorbed was in accordance with the Langmuir equation. At higher concentrations this relationship broke down and it is postulated that this is due to differing adsorption sites.In desorption studies, the amount of sulphate released decreased with each successive extraction. Only 32.7% and 76.4% of the initially adsorbed sulphate was recovered in four KH₂PO₄ extractions from Montserrat clay and Montreal sandy loam, respectively. This is ascribed to the different properties of the two soils.Sulphate adsorption was related to the percentage of NaOH-extractable aluminium in the soil.     

Molecular characterization and interactome analysis of aerolysin (aer) gene from fish pathogen Aeromonas veronii: The pathogenicity inferred from sequence divergence and linked to histidine kinase (cheA)

Aerolysin (aer) is one of the most important and abundant virulence factors in the infection of fish by Aeromonas veronii. A comprehensive study on the molecular characterization and pathogenicity of the aer gene from 34 A. veronii isolates from diseased carp and catfish was carried out and its interactome was analysed to observe the functional correlations between aer and other proteins within the A. veronii network. The PCR‐based amplification of aer from the 34 isolates of A. veronii showed more aer‐positive isolates from catfish with a high pathogenic potential in the in vivo challenge test than the carp fish. The analysis of aer gene sequence from challenged fish revealed significant sequence divergence according to the types and geographical distribution of the fish. The networking analysis of aer from the model A. veronii B565 revealed histidine kinase (cheA) as the most functional interacting partner. The study of the interaction between aer from the experimental A. veronii and cheA demonstrated that the A chain of cheA plays a more important role than the corresponding B chain during contact, and a linker sequence of 15 residues controlled the entire interaction process. Therefore, cheA could be an excellent drug target for controlling A. veronii infection of fish.     

Leucaena hedgerow intercropping and cattle manure application in the Ethiopian highlands I. Decomposition and nutrient release

 A litter bag technique was used to study the decomposition and release of N, P, K, Ca, and Mg from Leucaena leucocephala and L. pallida prunings and cattle manure in a hedgerow intercropping trial conducted in the Ethiopian highlands. Hedgerow intercropping (also called alley cropping or alley farming) is an agroforestry system in which trees are grown in dense hedges between alleys where short-cycle crops are grown. The hedges are pruned periodically during the cropping period and the prunings are added to the soil as green manure. Manure was the most resistant to decomposition, losing only 15% of its dry matter (DM) in 15 weeks, compared to 41–57% lost by leucaena prunings. Large quantities of K (up to 104 kg ha^–1) were mineralized from prunings and manure, but Ca and Mg were mostly immobilized. More N and P were released from prunings than from manure, which resulted in net immobilization of these nutrients in the initial stages of decomposition and net mineralization in later stages. Between the leucaenas more N was mineralized and less Ca and Mg were immobilized when L. leucocephala prunings were applied than when L. pallida prunings were applied. Fertilizer N increased DM decomposition and N mineralization. Mineralization of the nutrients was constrained by lignin and polyphenol contents. It is concluded that leucaena mulch and cattle manure may be significant sources of N and K for crop growth, but external sources of P, Ca and Mg may be required, particularly in acid soils which have low contents of these nutrients. However, this fertility effect has to be evaluated against the competition effect of trees to predict crop response. Received: 27 January 1997     

Binding of mercury compounds to the chloroplasts in relation to the inhibition of the Hill reaction

The binding behavior of mercuric chloride (HgCl₂), phenylmercuric acetate (PMA), and ethylmercuric chloride (EMC) to the spinach chloroplasts in relation to the inhibition of the Hill reaction was studied at pH 6.8 and 7.8 using ²⁰³Hg labeled compounds. The pH of the reaction medium did not influence the amount of mercury binding of the chloroplast at various mercurial concentrations, but it altered the inhibition curve of the Hill reaction. Between 0–1 × 10^?5M the binding of Hg²⁺ and EMC were similar and increased linearly with the concentration, while the binding of PMA was similar to the binding of Hg²⁺ only at a concentration below 4 × 10^?6M and was less when the concentration was above 4 × 10^?6M. However, the inhibition of the Hill reaction by these mercury compounds was quite different; at pH 7.8, the I₅₀ values for Hg²⁺, PMA, and EMC were 5 × 10^?6, 2.5 × 10^?6, and 2.5 × 10^?6M, respectively, while at pH 6.8, these values were 4 × 10^?6, 4 × 10^?5, and 2 × 10^?4M, respectively. The differential block of electron flow by the mercury compounds at pH 6.8 and 7.8 was further confirmed by electron spin resonance study.     

Binding of organophosphate insecticides to lecithin: A proton magnetic resonance study

The interaction of four vinyl-type organophosphate insecticides with a phospholipid lecithin has been studied by proton magnetic resonance technique. The vinyl proton of organophosphate showed a low field chemical shift change when lecithin was added to a CCl₄ solution of the former. When organophosphate insecticide was added to a dilute solution of lecithin the choline protons peak also showed small chemical shift changes. These chemical shift changes suggest that the most probable binding site in the interaction involves a hydrogen bond formation between the vinyl proton and oxygen atom of phosphatidyl group of lecithin. Chemical shift data has been used to calculate the equilibrium constant of the interaction.     

Forest policy and sustainable forest management in Bangladesh: an analysis from national and international perspectives

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.