An Insight into Current and Future Production of Forage Crops in Zimbabwe

In Zimbabwe, most livestock are reared by smallholder farmers who live in marginal areas with low rainfall and hence poor forage production. As a consequence, livestock productivity is low and intermittent droughts result in animal mortalities. Forage crops have been widely promoted to provide feed resources to livestock, particularly during the dry season and in years of low precipitation. However, production of forage crops among the smallholder farmers remains low, especially in areas that receive low rainfall (800 mm per annum) rainfall areas is highlighted. Planting of improved grasses and herbaceous legumes in fallows and tree legumes as hedges and on contours hold the best promise in terms of improving the availability of forage crops for livestock feeding. Shortage of moisture remains the greatest constraint to increasing the area planted to forage crops. Therefore, the development of irrigation facilities needs to be encouraged to allow for the growing of forage crops

Ecology of Woody Plants in African Savanna Ecosystems

Woody plants are key components of African savanna ecosystems as they provide wildlife habitats, offer browsing to ungulates and are also a major source of fuel wood. Disturbance events such as herbivory and fire negatively affect woody plant communities. However, some woody plants respond to disturbance events through resprouting. In savanna ecosystems, woody plants co-occur with grasses and disturbance events such as overgrazing result in the proliferation of woody plants at the expense of the grasses. Therefore, an understanding of the factors that influence woody plants is critical for the better management of African savanna ecosystems. This chapter reviewed our current knowledge of the ecology of woody plants in African savanna ecosystems and examined disturbance events such as herbivory and fire that shape woody plant communities. The role of resprouting as a response to disturbance events and the negative effects of woody plant encroachment on African savannas was also investigated. In addition, the consequences of poor management such as woody plants loss and possible restoration measures were explored. Disturbance events such as herbivory and fire were found to play critical roles in shaping the African savanna ecosystems. Interventions such as restoration have a role to play in restoring the productivity of degraded woody plant communities

Species composition and abundance of the spider fauna of the Hillside Dams Conservancy

Abstract: The objective of the study was to describe the spider species composition and abundance of a semi arid protected area in Zimbabwe, the Hillside Dams Conservancy. The paper aims to introduce a neglected group of invertebrates -the arachnids which is primarily unknown to science particularly in Zimbabwe. Spiders were collected in ten weekly sessions from last week of July to September 2012, using sweep nets and beating trays. A total of 663 individuals belonging to 28 species distributed among 11 families were found in the conservancy. The Oxyopidae was the most abundant (n = 230) representing 35% of all spiders sampled, followed by Philodromidae (n = 140) with 21%, Thomisidae (n = 124) with 19%, and Salticidae (n = 87) with 13%. The most abundant species was an Oxyopidae Oxyopes sp (n = 186) representing 28% of the total, followed by a Philodromidae Philodromus sp (n = 120) with 18.1%, a Salticidae Salticidae sp (n = 82) with 12.4%. The Thomisidae was the most species rich family with twelve species, followed by Philodromidae with four species and the Oxyopidae with three species. Observed spiders belonged to five functional groups: stalkers, foliage wanderers, ambushers, orb weavers and ground wanderers in the ratio of 3: 3: 6:2:1 with regards to species richness. Spider diversity in protected areas in Zimbabwe is not yet well known despite their usefulness as indicators of the overall species richness and status of ecosystems, therefore this study sought to fill the existing void of Arachnology literature for the state and apprise future investigators of the spider fauna of Zimbabwe

Quasifree Electron Bremsstrahlung Induced by Projectile Field

開始ページ、終了ページ: 冊子体のページ付

Polarization Effect of Orbital Electrons in High-Energy Impact

開始ページ、終了ページ: 冊子体のページ付