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ABSTRACT. We investigated vegetation dynamics in relation to livestock grazing as perceived by pastoral farmers in different regions of Botswana. A structured questionnaire was used to collect farmers' understanding of vegetation changes and causes within three different grazing lands. The pastoral farmers' description of dominant vegetation differed significantly both at the local and district level, which suggests that rangelands consist of patches dominated by different grasses and woody vegetation. Most pastoralists indicated that grass composition has undergone changes, and unpalatable grasses such as Aristida congesta and Megaloprotachne albescens are increasing. The different factors perceived by pastoral farmers to cause changes in vegetation composition included rainfall, overgrazing, and fire. Bush encroachment is considered to be more common in communal grazing land than in ranches. According to pastoral farmers, the ranching system is less degrading to the environment and more sustainable for livestock production than is communal grazing.

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Land use change from intensive arable production to extensively managed grasslands is encouraged through subsidy payments to farmers under the European Union's Common Agricultural Policy. Created grasslands are sown with a species-rich seed mix and receive limited or no fertiliser application with the aim of increasing the provision of non-production ecosystem services. In the UK these agri-environment schemes are funded for periods of 5, 7 or 10 years. This study compared the plant diversity and soil properties of paired intensively managed (IM) arable and recently created (3, 5, 8 and 9 years) extensively managed speciesrich grasslands (SRG) at 4 sites in the Scottish Borders. Botanical surveys of the newly created grassland plots showed limited establishment of the species-rich seed mixes and the dominance of grasses that favour more nutrient-rich environments. Soil properties at 0-10 and 30-40 cm depths were measured over 2 consecutive years. Total and available soil nitrogen, phosphorus and soil organic carbon were not significantly different between paired plots. This study indicates that in order to create edaphic conditions for species-rich grassland communities to develop within a 10 year timespan on former intensively managed arable land, radical changes in soil properties are required, which current de-intensification managements are not achieving.

The effectiveness of plant growth promoting bacteria (PGPB) in improving metal phytoremediation is still limited by stunted plant growth under high soil metal concentrations. Meanwhile, mixed planting with leguminous plants is known to improve yield in nutrient deficient soils but the use of a metal tolerant legume to enhance metal tolerance of a phytoremediator has not been explored. We compared the use of Pseudomonas brassicacearum, Rhizobium leguminosarum, and the metal tolerant leguminous plant Vicia sativa to promote the growth of Brassica juncea in soil contaminated with 400 mg Zn kg(-1), and used synchrotron based microfocus X-ray absorption spectroscopy to probe Zn speciation in plant roots. B. juncea grew better when planted with V. sativa than when inoculated with PGPB. By combining PGPB with mixed planting, B. juncea recovered full growth while also achieving soil remediation efficiency of >75%, the maximum ever demonstrated for B. juncea. μXANES analysis of V. sativa suggested possible root exudation of the Zn chelates histidine and cysteine were responsible for reducing Zn toxicity. We propose the exploration of a legume-assisted-phytoremediation system as a more effective alternative to PGPB for Zn bioremediation.