The Kobresia pygmaea ecosystem of the Tibetan highlands - Origin, functioning and degradation of the world's largest pastoral alpine ecosystem: Kobresia pastures of Tibet.

With 450,000 km2Kobresia (syn. Carex) pygmaea dominated pastures in the eastern Tibetan highlands are the world's largest pastoral alpine ecosystem forming a durable turf cover at 3000-6000 m a.s.l. Kobresia's resilience and competitiveness is based on dwarf habit, predominantly below-ground allocation of photo assimilates, mixture of seed production and clonal growth, and high genetic diversity. Kobresia growth is co-limited by livestock-mediated nutrient withdrawal and, in the drier parts of the plateau, low rainfall during the short and cold growing season. Overstocking has caused pasture degradation and soil deterioration over most parts of the Tibetan highlands and is the basis for this man-made ecosystem. Natural autocyclic processes of turf destruction and soil erosion are initiated through polygonal turf cover cracking, and accelerated by soil-dwelling endemic small mammals in the absence of predators. The major consequences of vegetation cover deterioration include the release of large amounts of C, earlier diurnal formation of clouds, and decreased surface temperatures. These effects decrease the recovery potential of Kobresia pastures and make them more vulnerable to anthropogenic pressure and climate change. Traditional migratory rangeland management was sustainable over millennia, and possibly still offers the best strategy to conserve and possibly increase C stocks in the Kobresia turf.

Career, collections, reports and publications of Dr Francis Buchanan (later Hamilton), 1762-1829: natural history studies in Nepal, Burma (Myanmar), Bangladesh and India. Part 1.

During his 20-year career as a surgeon-naturalist with the British East India Company, Francis Buchanan (later Hamilton, known in botany as Buchanan-Hamilton and in ichthyology as Hamilton-Buchanan) undertook pioneering survey explorations in several diverse regions of the Indian subcontinent. A naturalist at heart, his collections of plants and animals are often the first from such regions, notably Nepal, Burma (Myanmar) and Bangladesh. Buchanan had wide-ranging interests beyond natural history, using his talent for observation and meticulous recording to amass a huge body of information on the lands and peoples he encountered. However, much of this information remains unpublished in his survey reports, journals and other manuscripts, and so his role in the building of knowledge for these areas has been under-appreciated. Although a keen and able botanist, it is ironic that his multitudinous botanical discoveries are particularly poorly known, with the vast majority of his material on this subject languishing unpublished in archival collections. These include his original records and working notes which show the methods he used when dealing with 'information overload' and arranging his syntheses ready for publication. Notable is his experimentation with Jussieu's Natural System for classifying his Nepalese plants, and his recognition of biogeographic links of the Nepalese flora with Europe and Japan - both ahead of his fellow countrymen in Britain and India. The life of Francis Buchanan awaits the attention of a biographer who can do justice to his many interests, activities and influences. This is the first of two papers covering his life, providing an empirical baseline for future research and correcting misinformation that abounds in the literature. These papers outline Buchanan's professional career, concentrating on his activities in the exploration of natural history, and placing them in the wider context of botanical research in India.