Prosopis

Biomass, particularly fuel wood and charcoal, provides more than 14% of the world’s total primary energy and plays a critical role in meeting the energy requirements of developing countries, particularly in Sub-Saharan Africa. In Kenya it is estimated that 90% of rural households use fuel wood or charcoal, with fuel wood meeting the energy needs of over 93% of rural households, and charcoal being the dominant fuel in urban households.
Biomass energy resources, in the form of trees, are derived from forests - closed forests, woodlands, bush lands, grasslands, farmlands and plantations as well as from agricultural and industrial residues. Currently there is a growing imbalance between biomass energy supply and demand, with a deficit of almost 60%. This imbalance exerts considerable pressure on forest and vegetation stocks and accelerates the processes of land degradation and desertification.
Charcoal production depends predominantly on woody biomass hence the rising demand for charcoal as a household fuel is associated with increasing levels of deforestation. To address this challenge, on-farm cultivation of fast maturing tree and shrub species which can produce high quality charcoal and adapt to a wide range of climatic conditions is crucial.
This publication discusses some of the trees and shrubs that are suitable for sustainable charcoal production, for example Tarchonanthus camphoratusis (Leleshwa), Prosopis juliflora (Mathenge), Acacia drepanolobium (Whistling thorn) and bamboo. The publication also discusses case studies on best practices in tree management from Sudan, Kenya and Uganda. For example in Siaya County (Kenya) communities have raised Acacia polyacantha and A. xanthophloea trees through an initiative that started in 2002. The group of 545 farmers have set aside 240 hectares and planted woodlots for charcoal production on land pieces ranging from 0.5 – 3 acres (0.21 - 1.25 hectares) with a 6-year harvesting cycle. In Kajiado County a private business known as Musaki Enterprises established a 2.5 acre (1.05 hectare) arboretum with a total of 24 tree species adapted to dry land. The initiative which started in 1996 focuses on innovative research on the production, management, and processing of wood and charcoal biomass resources. They also develop and produce new and original designs of energy efficient technologies that include charcoal and wood-burning cook stoves for households and small businesses.
Efforts towards sustainable tree production and management for fuel wood and charcoal production are affected by various barriers and constraints. Land tenure for private land, trust land or state owned land can affect the production system if any conflicts in land ownership occur during the tree growing cycle. Lack of proper management plans as provided for under the Forests Act of 2005 can affect sustainable feedstock management. The arid and semi-arid areas of Kenya where majority of charcoal is produced are water deficient environments that experience challenges in vegetation growth and tree regeneration. This highlights the need for proper agronomic planning.
In conclusion, since charcoal is an integral part of Kenya’s economy and socio-cultural life it is important to intensify sustainable tree production. Strategies for achieving sustainable tree growing for charcoal production include:
• Ensuring successful charcoal production and marketing through implementation of existing charcoal policy guidelines and developing additional policies which
Sustainable Feedstock Management for Charcoal Production in Kenya 3
4 Sustainable Feedstock Management for Charcoal Production in Kenya
encourage investments in improved charcoal processing technologies.
• Encouraging establishment of woodlots of high density trees, promoting species of low density that are appropriate for briquetting, such as bamboo, and encouraging utilisation of agricultural residues and industrial residues such as sawdust and bagasse for fuel.
• Promoting the use of improved charcoal kilns (with efficiency of more than 25%); currently majority of charcoal producers use the traditional earth kilns with 10-20% efficiency.
• Encouraging the use of dry wood during carbonisation and promoting appropriate technologies that are simple, affordable and easy to adopt.
• Promoting energy conservation through the use of improved cook stoves with higher efficiency levels.
• Streamlining the charcoal value chain through collaborative action among all players in the sector, including farmers.
• Enhancing implementation of land use regulations and guidelines, especially where changes in land use occur.

Ecological monitoring in arid rangelands is highly suited to the use of low-altitude aerial imagery captured by drone, due to the habitat consisting of large areas with low biomass and biodiversity. Adoption of the technology requires broad expertise in ecology, drone hardware, and data interpretation, usually by a very small team or even an individual. Typically, an ecologist will first understand hardware, and only later develop the skills for interpretation. The aim of this paper is to facilitate this final step, by providing a detailed guide for optimizing image quality during data collection, combining images into a 3D photomosaic, and then using object based image analysis to extract useful information. Two case studies illustrate methods; Vegetation footprint calculation in a Prosopis cineraria plant community and distribution of Uromastyx aegyptia leptieni population via analysis of burrow entrances.

The dry forest of the Peruvian south coast has undergone an almost total process of deforestation. Populations here have increased exponentially through immigration supplying labour to urban coastal development, and demonstrably unsustainable agro-industrial expansion for export markets. Society has become dislocated from local traditions of environmental and resource management whilst still retaining a wealth of Andean agricultural expertise. Indigenous communities still hold on to vestiges of traditional knowledge. Relicts of natural vegetation, traditional agriculture and agrobiodiversity continue to sustain ecosystem services. Moreover, offer livelihood options and resources for restoration. These aspects reflect a long cultural trajectory, including famous extinct cultures such as Nasca, that evolved within an ever-changing riparian and agricultural landscape influenced by external forces and which incorporated important processes of plant domestication and adaptation to climatic oscillation.

Here, we present an ecosystem approach to vegetation restoration and sustainable resource management in Ica, Peru, based on wide interdisciplinary biodiversity inventory and study, where school, community and agro-industry engagement is seen as a prerequisite for success. The approach demonstrated significant plant establishment in this hyperarid region using appropriate low-technology techniques of planting and irrigation with minimum watering. Restoration of a highly degraded environment built upon vegetation relicts followed a strategy of cultural capacity building and environmental engagement, including the development of sustainable forest products, festivals, schools programmes, didactic publications for local use, and collaboration with local communities, landowners, agribusiness and governmental authorities. Plant conservation must re-engage people with their natural heritage by dissemination of information for vegetation restoration and management integrated to dynamics of ecosystem function within its wide local cultural and historical context.

Keywords: agriculture; archaeology; desert; huarango; Ica; local communities; Nasca culture; Prosopis

Los macrorrestos vegetales recuperados en el sitio Los Conitos (noroeste de Mendoza, Argentina) proporcionan evidencia del consumo y manejo de especies de plantas silvestres y domésticas. Con base en estos datos, el objetivo de este trabajo es mejorar nuestra comprensión del proceso socioeconómico de recolección y manejo de especies de plantas durante el Holoceno Tardío. El método de recuperación fue cribado en seco. La cronología se basa en ocho fechas de radiocarbono que abarcan los últimos tres mil años, que se evalúan junto con los restos macrobotánicos. De los 207 restos, Prosopis (“algarrobo”) fue el más ubicuo. Los niveles de excavación se agruparon en cuatro componentes de ocupación. En el com- ponente IV más antiguo, no se documentaron taxones vegetales; el componente III incluye la presencia más temprana de restos de plantas domésticas, Cucurbita (“zapallo”) y un predominio de especies de plantas silvestres; el componente II muestra una diversificación del uso de los recursos vegetales; final- mente, el componente I incluyó solo plantas silvestres. Se proponen algunas explicaciones alternativas de la incorporación, reemplazo y/o permanencia de las prácticas productoras y recolectoras que pueden vincularse a: estrés abiótico que afecta las prácticas hortícolas, aumento e intensificación demográfica y la llegada de migrantes con una base de subsistencia diversificada. La conclusión principal nos permite esbozar una imagen de la implementación de sistemas hortícolas de pequeña escala que comenzó hace alrededor de 1500 años, durante los cuales la recolección siguió siendo importante para la subsistencia.

The lower Ica Valley on the hyperarid south coast of Peru is today largely depopulated and bereft of cultivation, yet its extensive archaeological remains attest to substantial prehispanic populations. This paper describes archaeological investigations to retrace changes in geomorphology, ecology, and land- use in Samaca, one of the riparian oasis basins of the lower Río Ica, with the aim of investigating when, how, and why such changes took place. Archaeological interpretations of culture change in the region often invoke the impacts of major ENSO perturbations (El Niño). While our investigations confirm
that major ElNiño events around the end of the Early Intermediate Period likely offer part of the explanation for marked landscape change in the Samaca Basin, we also demonstrate the significance of more gradual, human- induced destruction of Prosopis pallida (huarango) riparian dry- forest. Huarango is a remarkable leguminous hardwood that lives for over a millennium and provides forage, fuel, and food. Moreover, it plays a crucial role in integrating fragile desert ecosystems, enhancing soil fertility and moisture, and accomplishing desalination and microclimatic amelioration. We propose that south coast valleys remained densely forested well into the Early Intermediate Period, attenuating the impact of El Niño events and supporting hitherto underappreciated agroforestry adaptations. Gradual deforestation eventually crossed an environmental threshold: river and wind erosion increased dramatically and precipitated radical desertification, feeding back into cultural changes in the Middle Horizon. Thus we argue Prosopis- human ecological relationships merit proper recognition in our archaeological interpretations of the south coast of Peru.

The aim of this paper is to analyse continuities and changes in plant diversity and use in the southern part of the Santa María valley in northwest Argentina, from the 1st millennium AD up to the Spanish Conquest in the 16th century. Variable degrees of association between people and plants (wild, weedy and domesticated), as well as various management practices (gathering, cultivation, tolerance, eradication, protection and encouragement) were investigated to find out biocultural history through the analysis of plant macroremains from archaeological sites. Samples were obtained from four archaeological sites, Rincon Chico 1, Rincon Chico 15, Soria 2 and El Colorado, located in the valley. As a result we identified 628 macroremains belonging to 20 taxa and determined whether they were either wild plants, weeds or crops, related to strategies of gathering and cultivation. The results suggest that there were changes through time, with a dominance of ruderal weeds in the earliest of the...

The aim of this paper is to analyse continuities and changes in plant diversity and use in the southern part of the Santa María valley in northwest Argentina, from the 1st millennium ad up to the Spanish Conquest in the 16th century. Variable degrees of association between people and plants (wild, weedy and domesticated), as well as various management practices (gathering, cultivation, tolerance, eradication, protection and encouragement) were studied to investigate the biocultural history of this region through the analysis of plant macroremains from archaeological sites. Samples were obtained from four archaeological sites located in the valley, Rincón Chico 1, Rincón Chico 15, Soria 2 and El Colorado. As a result, we identified 628 macroremains belonging to 20 taxa and determined whether they were either wild plants, weeds or crops, related to strategies of gathering and cultivation. The results suggest that there were changes through time, with a dominance of ruderal weeds in the earliest of the archaeological sites along with a diversity of association degrees, while a division was found between wild and domesticated plants, represented by maize and Prosopis (algarrobo), in the sites of the Late period. This last scenario suggests that the growing of trees and shrubs together with crops and pasture (agroforestry), or woodland management together with grazing (silvopasture), could have been part of the past land management practices in the area. Chenopodium remains indicate past complexes of wild plants, weeds and crops growing together in the cultivated plots; the newly introduced crops brought from Spain, such as wheat and barley, did not replace the local plants, mainly Prosopis (algarrobo) and Zea mays (maize), which were still grown during early colonial times. This paper offers a diachronic per‑ spective on plant management in a particular region, considering a plant record that is still limited, but which allows us to get a first glimpse of how plant management strategies may have changed in this part of South America.

Salinity can affect germination of seeds either by creating osmotic potentials that prevent water uptake or by toxic effects of specific ions. Most studies have only used monosaline solutions, although these limit the extent to which one can interpret the results or relate them to field conditions. The aim of this work was to evaluate the germination of Prosopis strombulifera seeds under increasing salinity by using the most abundant salts in central Argentina in monosaline or bisaline iso-osmotic solutions, or in solutions of mannitol and polyethylene glycol. Seeds were allowed to germinate under controlled conditions in a germination chamber at 30 +/- 1 degrees C and at 80 % r.h. Salinizing agents were KCl, NaCl, Na(2)SO(4), K(2)SO(4), NaCl + Na(2)SO(4) and KCl + K(2)SO(4) and osmotic agents were polyethylene glycol 6000 and mannitol. Treatments for all osmotica consisted of 0.0, -0.4, -0.8, -1.2, -1.5, -1.9 and -2.2 MPa solutions. The percentage of germination decreased as salini...