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Understanding the strategies that confer resilience on natural woodlands in drought prone environments is important for the conservation of these and similar ecosystems. Our main aim in this 2-year study was to assess traits (sapwood area, sapwood density and leaf area index) that control transpiration in Eucalyptus camaldulensis and E. microcarpa in a natural forest in which topographical variation created surface soils of sandy clay in a depression (clay-zone) and of loamy sand underlain by a dense profile on the terraces (sand-zone). The clay-zone had a wetter profile due to extra water supply through subsurface lateral flow from the adjoining, topographically higher, sand-zone. In the clay-zone, the differences between the two tree species in their hydraulic attributes were large and rates of water use were widely divergent. Rates of transpiration per unit land area (Ec) and canopy conductance of E. camaldulensis that was dominant in the clay-zone were about 50% lower than those for E. microcarpa in the same zone. This was in marked contrast to the behavior of trees growing in the sand-zone where water availability was persistently low and variations in sapwood density, sapwood area and canopy conductance were narrow. This resulted in almost identical rates of water use for the two species in the sand-zone, despite E. microcarpa dominating the stand. Contrary to many previous studies, sapwood density was positively correlated with Ec in these eucalypt species, while the proportion of trunk area assigned to sapwood declined with sapwood density. Consequently in this low rainfall environment, with prolonged dry seasons, dense sapwood safeguards against turgor loss, and possibly xylem embolism, thereby allowing Ec to be sustained under extremely low soil-water availability. We concluded that variation in hydraulic traits is less likely where trees are under persistent water-stress than where the stress is short and relatively mild. We developed single functions for

Understanding the strategies that confer resilience on natural woodlands in drought prone environments is important for the conservation of these and similar ecosystems. Our main aim in this 2-year study was to assess traits (sapwood area, sapwood density and leaf area index) that control transpiration in Eucalyptus camaldulensis and E. microcarpa in a natural forest in which topographical variation created surface soils of sandy clay in a depression (clay-zone) and of loamy sand underlain by a dense profile on the terraces (sand-zone). The clay-zone had a wetter profile due to extra water supply through subsurface lateral flow from the adjoining, topographically higher, sand-zone. In the clay-zone, the differences between the two tree species in their hydraulic attributes were large and rates of water use were widely divergent. Rates of transpiration per unit land area (Ec) and canopy conductance of E. camaldulensis that was dominant in the clay-zone were about 50% lower than those for E. microcarpa in the same zone. This was in marked contrast to the behavior of trees growing in the sand-zone where water availability was persistently low and variations in sapwood density, sapwood area and canopy conductance were narrow. This resulted in almost identical rates of water use for the two species in the sand-zone, despite E. microcarpa dominating the stand. Contrary to many previous studies, sapwood density was positively correlated with Ec in these eucalypt species, while the proportion of trunk area assigned to sapwood declined with sapwood density. Consequently in this low rainfall environment, with prolonged dry seasons, dense sapwood safeguards against turgor loss, and possibly xylem embolism, thereby allowing Ec to be sustained under extremely low soil-water availability. We concluded that variation in hydraulic traits is less likely where trees are under persistent water-stress than where the stress is short and relatively mild. We developed single functions for

BACKGROUND: While innovations in medicine, science and technology have resulted in improved health and quality of life for many people, the benefits of modern medicine continue to elude millions of people in many parts of the world. To assess the potential of genomics to address health needs in EMR, the World Health Organization's Eastern Mediterranean Regional Office and the University of Toronto Joint Centre for Bioethics jointly organized a Genomics and Public Health Policy Executive Course, held September 20th-23rd, 2003, in Muscat, Oman. The 4-day course was sponsored by WHO-EMRO with additional support from the Canadian Program in Genomics and Global Health. The overall objective of the course was to collectively explore how to best harness genomics to improve health in the region. This article presents the course findings and recommendations for genomics policy in EMR. METHODS: The course brought together senior representatives from academia, biotechnology companies, regulatory bodies, media, voluntary, and legal organizations to engage in discussion. Topics covered included scientific advances in genomics, followed by innovations in business models, public sector perspectives, ethics, legal issues and national innovation systems. RESULTS: A set of recommendations, summarized below, was formulated for the Regional Office, the Member States and for individuals.* Advocacy for genomics and biotechnology for political leadership;* Networking between member states to share information, expertise, training, and regional cooperation in biotechnology; coordination of national surveys for assessment of health biotechnology innovation systems, science capacity, government policies, legislation and regulations, intellectual property policies, private sector activity;* Creation in each member country of an effective National Body on genomics, biotechnology and health to:- formulate national biotechnology strategies- raise biotechnology awareness- encourage teaching and t