HO ‐ initiated oxidation of acridine and aminacrine in aqueous media: Kinetic model

The photodecomposition of diluted aqueous solutions of acridine and aminacrine in the presence of hydrogen peroxide was studied. Irradiation was carried out with a low pressure mercury vapour lamp. The kinetic model describes the photodegradation rate of the organic compound with respect to the technological parameters of the reactor and provides the reaction rate constants of hydroxyl radicals towards these two molecules. This model was extented to high hydrogen peroxide concentrations ([H₂O₂] > 200 μmol/l) by considering the reactivity of hydroxyl radicals towards hydrogen peroxide. This assumption allows us to define an optimal hydrogen peroxide concentration.     

Rainwater composition as a function of the cloud type

The influence of the type of clouds that produce precipitation in the rainwater composition was analyzed. Logroño, a remote station in the North of Spain was chosen for the analyses. Results prove that the rainwater composition from Cumulonimbus is different to the composition of the rainwater from the other clouds. In addition, the source of NO₃ ^? and SO₄ ^2? is studied in the different types of clouds. It is shown that the source is the soil except Stratocumulus formed from Cumulus in which the source is the gas‐particle conversion.     

The estimation of bioconcentration factors of aromatic hydrocarbons by high‐performance liquid chromatography

The determination of Bioconcentration Factors (BCF) via HPLC capacity factors (k') has been studied, including the effect of column type and mobile phase composition on the correlation between log BCF and log k’. Values of BCF correlate well with the phenylsilica column capacity factors. The phenylsilica column followed by C18 column give better correlations than either C8 or C2 column. The use of HPLC with phenylsilica as stationary phase and methanol‐water as mobile phase in the prediction of BCF can be at least as good or better than the use of n‐octanol/water partitioning system. There are no significant differences in the correlations between log k’ and log BCF with the changes of methanol concentration in the mobile phase, and it seems that a high proportion of methanol in the eluent is required to obtain good results.     

Assessment of hydrocarbon emissions from diesel invert mud residues treated in a bioreactor

Hydrocarbon emissions from a diesel invert mud residue (DIMR) were monitored while the hydrocarbons were being biodegraded in a solid‐phase bioreactor. Five to twenty percent of the reduction in diesel hydrocarbons was attributed to evaporation depending on the treatment, i.e. homogenization, cultivation, and aeration. Most of these volatile hydrocarbons were linear C₈ — C₁₂ alkanes and one‐ring aromatics. Of the treatments aeration had the largest effect on emissions; forced air through the bottom of the bioreactor cells increased emissions by three times over that of the non‐aerated cells. Cultivation increased hydrocarbon emission concentration as much as twofold over the pre‐cultivation value, however, emissions returned to the original levels within 12 hours. Homogenization had the least effect of all treatments. Diurnally, the emission rate was 40% higher in late afternoon than at midnight; the cause of which was probably atmospheric fluctuations such as temperature and solar radiation. The effects of daily atmospheric fluctuations were empirically modeled and taken into account for determining the total volume of emissions.     

Determination and QSPR analysis of log Kow and log Koc for fluorine containing benzene derivatives

Octanol‐water partition coefficients (Kow) and soil organic carbon sorption coefficients (Koc) were determined for 14 fluorinated benzene derivatives. Quantitative structure‐property relationships were developed using molecular connectivity indices and quantum chemical parameters to analyze the most significant factors influencing these physico‐chemical properties of the compounds. The substitution by F in benzene derivatives has greater influence on Koc than on Kow.     

Evaluation of fodder quality of straw of different landraces of rice (Oryza sativa L.) under cultivation in the Kumaun Region of Indian Central Himalaya

Thirty landraces of rice collected from various locations, across an elevational gradient (1150–2400 m asl), in Kumaun, Central Himalaya and VL-206 (a high-yielding variety recommended for rainfed mountain area) have been evaluated, both in terms of quantity and nutritional quality of straw. Data were collected to estimate the percentage share of fodder in the overall biomass produced. The total biomass harvested at maturity was taken as productivity. In view of the severe scarcity of fodder in hill regions, particularly during winter months, straw was also examined for quality-linked biochemical parameters and dry matter digestibility (DMD) of fodder. The Crude Protein (CP) values ranged from 2.21% (Nandhani) to 6.33% (Dalbadal), and in saceo DMD (nylonbag technique) was highest in Kaladur (48.84%) and lowest in Kantolia (32.25%). While the CP in VL206 was within the range recorded for various landraces (3.61%), DMD value (27.29%) was lower than that of all the landraces tested. In saceo DMD data indicate that the fodder quality of landraces is better than that of the introduced variety. The values for neutral detergent fibre (NDF) ranged from 63.64% (Sabhawati) to 78.46% (Chhotiya) among the rainfed landraces, while in the irrigated landraces, Thapchini had more NDF (87.50 %), as compared to Kantolia (73.88%) and VL206 (74.91%). Values for the acid detergent fibre (ADF) varied from 42.70% (Danbasmati) to 54.58% (Nandhani) in the rainfed group; ADF was slightly higher in Thapchini (49.41%) in comparison to Kantolia (47.19) and VL206 had the highest (56.80%) ADF content. The observed differences with respect to straw productivity, chemical composition and in saceo DMD in various landraces, even when grown under similar conditions at one place, clearly indicate the richness of the gene pool of rice being maintained, through cultivation, in the Kumaun hills. It may be mentioned that agriculture in the hills is biomass based, and livestock form an integral component of subsistence farming.     

Ecoregions and ecosystem management in China

Ecological regionalization is a base for rational management and sustainable utilization of ecosystems and natural resources. It can provide a scientific basis for constructing healthy ecological environments and making policies of environmental management. In this paper, based on synthetic analysis of the characteristics of the ecology and environments of China, the principles of ecological regionalization are discussed, and indices and nomenclature of ecological regionalization are proposed. The ecoregions on a national scale are divided. The results show that there are 3 domains, 13 ecoregions and 57 ecodistricts. The present scheme can be used as a framework for ecosystem assessment and management. Based on the ecoregions, measurements of management for forest, grassland, agriculture and wetland ecosystems are recommended. The experience and information can be used within and beyond the national scale for land-use planning, biodiversity conservation and ecosystem restoration.     

Transboundary conservation: Development implications for communities in KwaZulu-Natal,South Africa

Conservation is increasingly promoted as a sustainable development instrument in Southern Africa, particularly for remote rural communities. Conservation and development schemes are marketed as community-based projects providing local empowerment through the creation of jobs and cash stemming from protected areas, as well as increased biodiversity protection by local communities whose jobs are dependent on the resource. Transfrontier Conservation Areas (TFCAs), mega Peace Parks that cross international borders, are one of the latest conservation and development paradigms in Southern Africa. TFCAs have gained broad support, including government recognition as a development tool. However, there has been minimal research on the impact of TFCAs on local communities. This paper seeks to provide an empirical case study of a South African community bordering the Lubombo TFCA (South Africa, Swaziland, Mozambique). Results are presented that indicate the Mbangweni community in KwaZulu-Natal could experience decreased access to social, natural, and economic resources as a result of the Peace Park.     

Capacity building in tropical coastal resource monitoring in developing countries: A re-appreciation of the oldest remote sensing method

Long-term decadal retrospection in spatio-temporal imagery analyses can only be carried out using aerial photographs, which are still the most detailed remotely sensed data available. Visual interpretation of such imagery is most efficient and inexpensive in the light of ecosystem monitoring research in developing countries, which are often unable to cope with the development or the cost of acquisition of commercial space-borne imaging (e.g. IKONOS, Quickbird). In this light, the present paper explicitly analyses the methodological use of image attributes of air-borne imagery from mangrove forests, and investigates the consistency and constraints of mangrove image attributes in visually interpreted air-borne imagery. Six image attributes are analysed, and their application is illustrated using various mangrove sites in Kenya and Sri Lanka. Comparison of identification keys reveals that minor attributes such as 'ecological position' are informative, and that image attributes for a particular species or genus are apparently less plastic and more widely applicable than formerly assumed. Emphasis on compulsory fieldwork is made and constraints related to reflection and interference, amongst others, are discussed.     

Indigenous ecological knowledge of Borana pastoralists in southern Ethiopia and current challenges

Indigenous ecological knowledge (IEK) of Borana pastoralists on strategies of sustainable resource utilization, forage species, ecological interactions, rangeland condition and trend was documented using discussions, a semi-structured questionnaire survey and analytical workshops. Traditional strategies of rangeland and water management were described and the most important forage species identified. Pastoralists' perceptions were compared across age, gender and site. There was a positive correlation between pastoralists' preference ranking of forage species and crude protein content of the species. IEK of men and women was complementary. The process of rangeland degradation was described as shortage of grass and decrease in density and frequency of highly palatable grass species, leading to low milk production and reduced conception rates in cows. The results confirmed that the IEK of these pastoralists could still provide the basis for sustainable resource utilization and rangeland rehabilitation. However, the young generation in the area had not only limited knowledge but also showed less interest to learn and apply the traditional resource management strategies. Therefore, there is high need to perpetuate, document and use this IEK for sustainable development. On the other hand, shortage of forage resources as a result of rangeland shrinkage (leading to rangeland degradation and woody plants encroachment), less application of IEK, the gap between traditional and formal systems, and trends of disobeying traditional rules and regulations were identified as current challenges for the Borana pastoralists.