Proposed thesis is focused on the role of soil microbial crusts in the extreme environmental conditions of high-elevation cold desert of W Himalaya. Despite the importance of microbial soil crusts in arid soils, the biodiversity of their microbial communities, their role and function are still unclear. Our knowledge about functioning of these outlying ecosystems in this part of the world is still very insufficient in general. The area of Ladakh is perfect place for studying the microbial soil crust arid climate and extreme elevation aroud 6000 m a.s.l. represents unique condition for well-developed soil crusts communities. The whole region is unaffected by human activities or plant invasions, so we can study soil crusts in pristine natural condition. Our investigations is focused on soil microbial community of BSCc in Ladakh region. It combines range of aspects connected with BSCs such as taxonomical composition, changes of diversity and activity in relation to environmental condition. The thesis is the first compilation of studies concerned on microbial communities in area of Ladakh and one of the first work investigating the ecophysiology of BCSs in cold desert.

The thesis raises questions concerning prehistoric conditions in a high mountain region in central Scandinavia; it focuses on the human use of stone and on hunting principally of reindeer. An analysis of how the stone material was utilized and an approach to how large mammals were hunted result in a synthesis describing one interpretation of how the vast landscape of a region in the central Scandinavian high mountains was used. With this major aim as a base questions were posed concerning the human use of stone resources and possible changes in this use. Preconditions for the occurrence of large mammals as game animals and for hunting are also highlighted. A general perspective is the long time period over which possible changes in the use of stone and hunting of big game, encompassing the Late Mesolithic, Neolithic, Bronze Age and to a certain extent the Early Iron Age. Considering the manufacture of flaked stone tools, debitage in the form of flakes from a dwelling, constitute the base where procurement and technology are essential. The occupation of the dwelling covers a period from the Late Mesolithic to the Bronze Age. Possible changes in lithic use are discussed based on an analysis of debitage which includes testing variables reflecting various steps in the process of flaked stone tool manufacture. Also, the results are discussed from a methodological aspect; the classificatory aspect of analyzing large flake assemblages is implied. The result of the flake analysis indicates differences in the use of stone from the Late Mesolithic to the Bronze Age/Early Iron Age. These differences are interpreted in a three-part chronological division and as theoretically proceeding in a manufacturing process of five steps including acquisition, reduction through three steps and use of completed tools. A pattern, dividing the Bronze Age use of stone from that of the Neolithic and Late Mesolithic is discerned and discussed in terms of changes in procurement strategies and technology. Also, social organization is touched upon. When approaching the issue of hunting the character of data differ; archaeological and palaeo-environmental data together comprise the base for a discussion of possible changes. This is based on a theoretical model applied in a hypothetical research design. Archaeological categories of remains relevant in hunting contexts together with ethnographic and traditional hunting techniques are discussed. They constitute the base and illustrate possible variables in the testing of the hypothetical model. Changes in the Holocene climate are clear, just as changes in the archaeological record are observable. Together these circumstances indicate changes in the hunting process. The structural changes in economy and society that occur in central and north Scandinavia during stone-using periods are discernible in the region studied here. / digitalisering@umu