Rice (Oryza sativa L.) is an important staple crop that feeds more than one half of the world's population and is the model system for monocotyledonous plants. However, rice is very sensitive to salinity and is the most salt sensitive cereal crop with a threshold of 3 dSm −1 for most cultivated varieties. Despite many attempts using different strategies to improve salinity tolerance in rice, the achievements so far are quite modest. This review aims to discuss challenges that hinder the improvement of salinity stress tolerance in rice as well as potential opportunities for enhancing salinity stress tolerance in this important crop.

Introduced species present the greatest threat to the unique terrestrial biodiversity of the Galapagos Islands. We assess the current status of plant invasion in Galapagos, predict the likelihood of future naturalizations and invasions from the existing introduced flora, and suggest measures to help limit future invasions. There has been a 1.46 fold increase in plant biodiversity in Galapagos due to alien plant naturalizations, reflecting a similar trend on islands elsewhere. There are 870 alien plant species recorded in the archipelago. Of evaluated species, 34% species have naturalized. Within this group are the invasive species (16% of evaluated) and the transformers (3.3% of evaluated). We show that, as expected, naturalized species have been present in the archipelago longer than non-naturalized species. We also find that a higher human-mediated propagule pressure is associated with a greater human population and with properties that have been settled longer. This, combined with the relatively recent introduction of most species, leads us to the conclusion that Galapagos is at an early stage of plant invasion. We predict that more species from the existing alien flora will find an opportunity to naturalize and invade as propagule pressure increases alongside rapid human population growth associated with immigration to serve the booming tourism industry. In order to reduce future invasion risk, we suggest reviewing inter-island quarantine measures and continuing community education efforts to reduce human-mediated propagule pressure.Resumen Las especies introducidas representan la mayor amenaza a la biodiversidad terrestre única de las Islas Galápagos. En este estudio, evaluamos la condición actual de invasión de plantas en Galápagos, predecimos la posibilidad de nuevas naturalizaciones e invasiones de la flora introducida existente, y sugerimos maneras para limitar invasiones en el futuro. Ha habido un incremento de 1.46 veces en total de biodiversidad de plantas en Galápagos atribuido a las naturalizaciones de plantas introducidas; este patrón se refleja en otras islas del mundo. Han sido reportadas 870 especies de plantas introducidas en el archipiélago. De las especies evaluadas, 34% están naturalizadas; dentro de este grupo están las especies invasoras (16% de las evaluadas) y las transformadores (3.3% de las evaluadas). Como se esperaba, se muestra que las especies naturalizadas han estado presentes en el archipiélago más tiempo que las especies no-naturalizadas. También encontramos que el incremento del número de individuos de las especies introducidas sembradas por los seres humanos está directamente relacionado con el tamaño de la población humana y con la antigüedad de las propiedades privadas. Este hecho, en combinación con la introducción relativamente reciente de la mayoría de las especies, nos lleva a la conclusión de que Galápagos está en las primeras etapas de invasión. Predecimos que más de las especies introducidas ya presentes van a encontrar una oportunidad para naturalizarse a medida que ...

Across the world’s rangelands, livelihoods of millions of people are dependent on customary and commercial use of wildlife. Many Australian Aboriginal communities also aspire towards developing natural resource-based enterprises but there is a unique combination of historical, legislative and cultural factors that make this process complex. Typically, government support for Indigenous enterprise development has focussed largely on development of ‘social enterprise’, with subsidies coming from various government community development programs. This has resulted in some increase in participation and employment, but often inadequate attention to economic aspects of enterprise development leading to low levels of business success. This paper will examine historical, legislative and institutional dimensions in business development in Aboriginal communities. It does this through a case study of business enterprise development of the Kakadu Plum products by the Indigenous people of the Thamarrurr Region of the Northern Territory, Australia, using a participant observation research method. We found that attention on important economic criteria was subsumed by a focus on social enterprise priorities during the development of this natural resource-based enterprise. This resulted in a very slow transition of the ‘social enterprise’ to the ‘financial enterprise’, due largely to fragmented business decisions and inefficient value chains. We call for a refocus of natural resource-based enterprise development programs in remote Australian Aboriginal townships to incorporate greater emphasis on business acumen within the complex social, cultural and political fabric.

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Invasion of grass weeds is a major threat for ecosystems. Mission grass (Cenchrus pedicellatus and C. polystachios) vigorously competes with native vegetation and has become a serious problem in northern Australian savanna. A lower density of mission grass has been observed under the canopy of stands of native Acacia holosericea. We used a series of laboratory and shade house experiments to assess the potential for allelopathy and the role of litter on germination, emergence and seedling growth of these two species of mission grass. Different concentrations of aqueous leaf extract of A. holosericea were used to assess allelopathic effects on germination. Various depths and types of litter were used to investigate the allelopathic and physical effects of litter on emergence and growth of mission grass seedlings in the shade house. Results indicate that extracts did not affect germination of either species of mission grass but root growth of seedlings was affected. Emergence of seedlings in the shade house was affected by physical litter treatments but not by allelopathy. After emergence no negative effects on seedling growth were detected. Overall we found that there was no allelopathic effect on germination and that the negative effect on emergence was due to the physical properties of the litter. This effect on emergence increased with increasing depth of litter. Allelopathy slightly inhibited root growth but once seedlings emerged, litter tended to facilitate growth. This has implications for the ecological management of mission grass on disturbed lands, using strategies such as manipulation of litter cover through Acacia establishment.