Key Technique of Gas Sucking of "Three-Soft" Coal Bed and Its Application
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The Evolution of Plants
A major new undergraduate textbook on plant evoution This is a broad but provocative examination of the evolution of plants from the earliest forms of life to the development of our present flora. Taking a fresh, modern approach to a subject often treated very stuffily, the book incorporates many recent studies on the morphological evolution of plants, enlivens the subject with current research on ancient D.N.A. and other biomolecular markers, and places plant evolution in the context of climate change and mass extinction. It is written to be accessible to undergraduates, so, for example, geological time is discussed in terms of 'millions of years ago' as well as by the names of the ages, and English equivalents of plant names are prefered, e.g. seed plants (instead of gymnosperms), flowering plants (instead of angiosperms). * Links up the trends/patterns seen in the fossil flora from the earliest green algae through to the present day. * Covers the whole geological timescale, but focuses the chapters on periods when major evolutionary changes occurred. * Special Biome Maps indicate the general trends in changing global plant distribution through time.
The contribution of charcoal production to rural livelihoods in a semi-arid area in Kenya
Forest incomes in the form of both timber and non-timber forest products are an important source of livelihood for many communities in Africa. A major forest resource is charcoal, which contributes to the livelihoods of millions across the region. While incomes from charcoal are used to meet a wide spectrum of needs within rural livelihoods, the role of charcoal production on livelihoods of small-scale producers is not well understood. Therefore, we provide an example on the importance of charcoal on livelihoods in an agropastoralist community in a semi-arid region in Kenya. Based on a household questionnaire targeting 150 charcoal and 150 non-charcoal makers, as well as focus group discussions, we assessed the determinants for participation in charcoal production and developed a household typology based on charcoal income dependence. We also determined the role of charcoal in income equalization and poverty reduction. Our study shows that charcoal contributes about 20% of the household income in the study area. Gender, land size and the number of food-scarce months are the key determinants of participation in charcoal production. Based on the poverty analysis, we conclude that even though charcoal income does not lift the producers out of poverty, it can mitigate the impacts of poverty by reducing the poverty gap and poverty severity. Based on our findings, we recommend a multipronged approach to address sustainable rural livelihoods including a more explicit acknowledgement of charcoal production as a source of rural income. We also recommend broadening of the local livelihood base and a more active management of the woodland to ensure the sustainability of the income.