Comparative studies on the structure of an upland African stream ecosystem

Upland stream systems have been extensively investigated in Europe, North America and Australasia and many of the central ideas concerning their function are based on these systems. One central paradigm, the river continuum concept is ultimately derived from those North American streams whose catchments remain forested with native vegetation. Streams of the tropics may or may not fit the model. They have been little studied. The Amani Nature Reserve in the East Usambara Mountains of north-eastern Tanzania offers an opportunity to bring these naturally forested systems to the attention of the ecological community. This article describes a comparison made between two lengths of the River Dodwe in this area. The work was carried out by a group of postgraduate students from eighteen European and African countries with advice from five staff members, as part of a course organised by the Tropical Biology Association. Rigorous efforts were made to standardise techniques, in a situation where equipment and laboratory facilities were very basic, through a management structure and deliberate allocation of work to specialists in each area.The article offers a summary of invertebrate communities found in the stream and its biomass. Crabs seem to be the key organism in both sections of the streams

Comparative studies on the structure of an upland African stream ecosystem

Upland stream systems have been extensively investigated in Europe,North America and Australasia and many of the central ideas concerningtheir function are based on these systems. One central paradigm, the rivercontinuum concept (Vannote et al. 1980) is ultimately derived from thoseNorth American streams whose catchments remain forested with nativevegetation

Characterization of Bioethanol Fuel from Rice and Corn Straws: A Comparative Study

In this study, the production and characterization of bioethanol from rice and corn straws were investigated.The bioethanol was produced through dilute acid hydrolysis, fermentation and distillation; and the distillateswere purified by dehydration using zeolite 4A. The physicochemical and fuel properties of the bioethanoldistillates including pH, refractive index, specific gravity, flash point, octane rating and calorific or heatingvalue were evaluated. Further characterization of the biofuel was carried out using FTIR and GC-MS. Theresults indicated that octane number, calorific value, and specific gravity of the corn straw bioethanol obtainedwere significantly higher (p<0.05) compared to rice straw bioethanol. Meanwhile, no statistically significantdifference (p˃0.05) was observed in the flash point, refractive index, pH, pour and cloud points of thebioethanol produced from the two lignocellulosic substrates. Furthermore, the results reveal that pH, octanenumber, specific gravity and flash point are within the ASTM standards while refractive index, cloud and pourpoint were slightly outside the ASTM standard. This reveal potential of the feedstock as a source for Bioethanolproduction