Desertification in southern Europe
The threat of desertification appears in southern Europe when periods of prolonged drought are followed by torrential rains falling on steep, unstable terrain. The plant cover of many regions has been degraded since very ancient times. Some are now recovering as a result of emigration and reduce pressure on the land. Tourist and commercial agricultural developments threaten habitat values and water supplies, especially in certain coastal areas. Relatively abundant archeological and literary resources offer excellent opportunities for tracing land use histories and throwing more light on the nature and direction of environmental change. Such longitudinal studies should be integrated with remote sensing and nested sampling on the ground of current landscape conditions and monitoring of current processes.
Some guidelines for monitoring desertification of Mediterranean drylands on the basis of plant water status
Drought stress can be considered as a dominant factor contributing to degradation of Mediterranean drylands. Therefore, there is a strong need to monitoring the level of water stress suffered by vegetation in the view of relating it to desertification risk of selected areas. In the present paper, some techniques for measuring and quantifying plant water stress are briefly reviewed and the advantages of using the pressure chamber technique to measure leaf water potential (ΨL) are highlighted. A new index (water stress impact on vegetation (WSIV)), based on the integral of the diurnal changes of ΨL, is proposed and its effectiveness for quantifying the amount of water stress suffered by vegetation is discussed on the basis of measurements performed in degraded areas of Turkey and Lebanon. The usefulness of WSIV as an ecophysiological tool for assessing the desertification risk of Mediterranean drylands is also discussed.
Fieldwork in geography teaching: A critical review of the literature and approaches
Abstract Virtually all lecturers in geography recognise the importance of fieldwork as a vital mode of teaching in the subject. This paper draws on material produced as part of a HEFCE review of teaching and learning in the field and assesses the implications of recent changes in higher education for field studies in geography. The literature on the development of, and recent changes in, fieldwork practice is reviewed and assumptions about appropriate forms of teaching and assessment are challenged. The need for carefully integrated preparation of project‐orientated fieldwork is stressed and the importance of debriefing and feedback after field visits is emphasised. Various suggestions for guidelines on good practice are presented. Finally, a range of future issues and problems in fieldwork is identified and discussed.