Resumen Los practicantes de la restauración y rehabilitación ecológica (RRE) carecen de información completa sobre los tratamientos pregerminativos más efectivos para promover la germinación de plantas nativas de regiones áridas y semiáridas, y sobre la supervivencia y crecimiento de estas especies a campo. Aquí informamos resultados del enfoque “estrategias profesionales inteligentes” para evaluar la germinación de especies del Monte Austral, una región árida del sur de Argentina. Nuestros objetivos fueron probar una pequeña cantidad de tratamientos pregerminativos que son efectivos en otras regiones áridas y evaluar los resultados de germinación de 16 especies en comparación con la información existente sobre su desempeño a campo. Este enfoque demostró ser altamente efectivo dado que, de las 16 especies de arbustos evaluadas, 11 mostraron tasas de germinación adecuadas para RRE (es decir, más del 50%). Solo cuatro especies alcanzaron altas tasas de supervivencia y altos valores de cobertura vegetal en las plantaciones, y otras cuatro mostraron altas tasas de supervivencia, pero la cobertura vegetal fue baja o no se evaluó. Argumentamos que sería estratégico adoptar este modelo, que incluye obtener y comparar información sobre la germinación de semillas y el desempeño de las mismas especies a campo, para la selección de especies en RRE.

Abstract Ecological restoration and rehabilitation (ERR) practitioners lack comprehensive information on the most effective seed dormancy alleviation treatments to enhance germination of native plants from arid and semiarid regions, as well as on survival and growth rates of these species in the field. In this paper we report on the results of a “professional intelligent tinkering” approach to assess seed germination of species from the Monte Austral, an arid region in southern Ar gentina. We aim to test a small number of seed dormancy alleviation treatments reported to be effective in other arid regions, and to assess germination results for 16 species against existing information on their performance in the field. This approach proved to be highly effective given that, out of the 16 shrub species evaluated, 11 showed germination rates suitable for ERR (i.e., over 50%). Only four species attained both high survival rates and plant cover values in out plantings, while four other species showed high survival rates but their plant cover values were low or not assessed. We argue that this approach, which involves obtaining and comparing data on seed germination rate with performance of the same species in the field, would be strategic for species selection in ERR.

Depois de listar os cinco elementos chave da restauração ecológica - ecologia, economia, valores sociais, valores culturais e política, eu celebro o fato de que no Brasil há uma legislação sobre como conduzir a restauração ecológica de florestas tropicais degradadas, bem como o diálogo em andamento entre legisladores e cientistas sobre essa legislação, e também o intenso debate entre cientistas sobre a melhor forma de avançar, referindo aos artigos de Brancalion et al. (2010) e Durigan et al. (2010) nessa edição da Revista Árvore. Legisladores de todas as regiões, especialmente de países de megadiversidade, devem tomar nota. Eu não tomei partido por um dos lados no debate; eu acredito que ambos os grupos de autores apresentaram pontos muito bons. Em vez disso, eu sugiro que os cientistas e legisladores ponderem cinco ferramentas estratégicas: A. comece com conceitos claros. B. analise onde se quer chegar e por que. C. Negocie quem deveria se beneficiar e como, e quem deveria pagar, como e por que. D. Exercite uma análise honesta de custo-benefício da restauração, independentemente do bioma onde se está trabalhando. Finalmente, analise como tornar a restauração atrativa de imediato para os proprietários rurais. Caso contrário, eles não vão cooperar efetivamente da forma como eles poderiam ou deveriam, e os esforços da restauração não irão alcançar seu potencial por completo.

After listing the five key elements of ecological restoration, ecology, economics, social values, cultural values, and politics, I celebrate the fact that in Brazil there is legislation on how to perform ecological restoration of degraded tropical forests, as well as an ongoing dialogue among legislators and scientists about this legislation, and also a lively debate among scientists as the best way forward, referring to articles by Brancalion et al. (2010) and Durigan et al. (2010) in this issue of Revista Árvore. Legislators elsewhere, especially megadiversity countries, should take note. I do not take sides in the debate; I think both groups of authors make very good points. Instead I call on the scientists and legislators concerned with restoration to ponder five strategic tools: A. Start with clear concepts. B. Decide where you want to go and why. C. Negotiate who should benefit & how, and who should pay, how, & why. D. Work out how an honest cost-benefit analysis of restoration would look, regardless of the biome in which you are working. Finally, figure out how to make the restoration immediately attractive for private landowners. Otherwise, they will not cooperate as fully as they could or should, and restoration efforts will not achieve its full potential.

South Africa in general has been approximately 2% hotter and at least 6% drier over the ten years between 1997 and 2006 compared to the 1970s. The use of water has also increased greatly over this same period. By 2000, 98.6% of that year's surface water yield and 41% of the annual utilisable potential of groundwater was allocated to use. Irrigation agriculture, comprising 60% of total consumption, is by far the largest single consumer of water. Given these climatic and water use changes as a backdrop, we employed a panel data econometric model to estimate how sensitive the nation's agriculture may be to changes in rainfall. Net agricultural income in the provinces, contributing 10% or more to total production of both field crops and horticulture, is likely to be negatively affected by a decline in rainfall, especially rain-fed agriculture. For the country as a whole, each 1% decline in rainfall is likely to lead to a 1.1% decline in the production of maize (a summer grain) and a 0.5% decline in winter wheat. These results are discussed with respect to both established and emerging farmers, and the type of agriculture that should be favoured or phased out in different parts of the country, in view of current and projected trends in climate, increasing water use, and declining water availability.