1,721,247 research outputs found
The use of plant water relations to characterise tree species and sites in drylands of Northern Ethiopia
No full textIntroducing Boswellia papyrifera (Del.) Hochst and its non-timber forest product, frankincense
No full textBosiwllia papyrifra has been an important Multipurpose tree species in central and eastern Africa since ancient times. The species is best known for its non-timber forest product, frankincense. In addition, it has numerous environmental, socio-economic, traditional and industrial uses. However, the species is declining at an alarming rate and thus needs priority in conservation. Populations are facing degradation due to agricultural expansion, overgrazing, fire, poor incense harvesting practices, shifting cultivation, termite and other infestations and urgent conservation measures are required to save the species. Conservation strategies could include promotion of natural regeneration through closed areas and enrichment planting. Nevertheless, more ecological and silvicultural studies are required in order to streamline specific interventions
The use of plant water relations to characterise tree species and sites in drylands of Northern Ethiopia
No full text
The use of plant water relations to characterize tree species and sites in the drylands of northern Ethiopia
No full textWater relations of four tree species were studied in four sites in the drylands of northern Ethiopia. Predawn water potentials were significantly higher at all sites as compared to midday measurements for Acacia etbaica and Boswellia papyrifera. In contrast, Lannea fruticosa revealed this significant difference only once, while Terminalia brownii at only two of the four sites. An analysis of variance showed that A. etbaica has a wider tolerance range as compared to the other species. There was no significant difference among the four sites in terms of predawn, midday and diurnal ranges of water potential. The study revealed that A. etbaica and B. papyrifera are performing better as compared to T brownii and L. fruticosa under the current climatic conditions. Understanding the physiological basis of survival, productivity, ability to cope with low moisture availability, and growth potential of indigenous species in the drylands is essential for the utilization and promotion of these and other species. (C) 2004 Elsevier Ltd. All rights reserved
Forest-related policies affecting bioenergy markets in Europe
No full textThe increasing interest in the use of forest biomass as a renewable energy source has activated policy developments at all geographical levels from international and national to local. Given their high relevance for actors in the sector we focus in this chapter on giving an overview of policies at the EU level that are relevant for the development of sustainable biomass energy from forests. These include: forest, climate, energy, rural development and trade policies, as well as synergies and connections among them
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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