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AbstractMost tropical forests outside protected areas have been or will be selectively logged so it is essential to maximize the conservation values of partially harvested areas. Here we examine the extent to which these forests sustain timber production, retain species, and conserve carbon stocks. We then describe some improvements in tropical forestry and how their implementation can be promoted. A simple meta‐analysis based on >100 publications revealed substantial variability but that: timber yields decline by about 46% after the first harvest but are subsequently sustained at that level; 76% of carbon is retained in once‐logged forests; and, 85–100% of species of mammals, birds, invertebrates, and plants remain after logging. Timber stocks will not regain primary‐forest levels within current harvest cycles, but yields increase if collateral damage is reduced and silvicultural treatments are applied. Given that selectively logged forests retain substantial biodiversity, carbon, and timber stocks, this “middle way” between deforestation and total protection deserves more attention from researchers, conservation organizations, and policy‐makers. Improvements in forest management are now likely if synergies are enhanced among initiatives to retain forest carbon stocks (REDD+), assure the legality of forest products, certify responsible management, and devolve control over forests to empowered local communities.

Abstract Australia is a major food exporting country. Recent droughts reduced dryland farming production and the volume of water allocated to irrigated agriculture, with a resulting decline in aggregate agricultural production and exports. This paper analyses the possible impact of increased water scarcity on Australian agricultural production and the magnitude of subsequent impacts on global food security. Using the Australian Bureau of Statistics (ABS) data on land and water use coupled with a hydro-economic stochastic modelling approach, the impacts of reduced agricultural production in the southern Murray–Darling Basin, and more generally for Australia, are analysed. Changes in agricultural activity, reduction in agricultural exports and altered composition of products exported attributed to the severe 2000–2009 drought are also analysed to highlight the implications for global food security. The impact of climate change on food production is examined. The analysis shows that climate change, when modelled as the extreme case, along with other factors such as land use, will impact Australian food exports. Despite its relatively small contribution to total global food supply, Australia’s contribution to international trade in wheat, meat and dairy products is substantial and could affect global food prices. Furthermore, Australia’s agricultural exports are of disproportionate importance within the South- and South–East Asian and Oceania region, both in terms of volume and for strategic reasons. Adaptation along with investment in agriculture production is needed to maintain Australian agricultural production and enhance global food security.

Climate change represents an unavoidable and growing challenge to food security, imposing new adaptation imperatives on all farmers. Maize is arguably the world's most productive grain crop, as measured by grain yield. However, maize yields vary dramatically due to many factors, including soils, climate, pests, disease, agronomic practices, and seed quality. The difference between observed yields and those achievable by optimized crop production methods is called the yield gap. In this work we quantified the current yield gap for 44 countries through the use of a large private-sector data set recently made available to the crop modelling community. The yield gap was quantified for three groups of countries, categorized by level of intensification. Observed yield gaps for high, medium, and low levels of intensification are 23%, 46%, and 68%, respectively. If all maize production countries were able to shrink their yield gap to 16.5% (as in the USA) an additional 335 million metric tons (MMT) of maize grain...

Degradation of freshwater ecosystems and the services they provide is a primary cause of increasing water insecurity, raising the need for integrated solutions to freshwater management. While methods for characterizing the multi-faceted challenges of managing freshwater ecosystems abound, they tend to emphasize either social or ecological dimensions and fall short of being truly integrative. This paper suggests that management for sustainability of freshwater systems needs to consider the linkages between human water uses, freshwater ecosystems and governance. We present a conceptualization of freshwater resources as part of an integrated social-ecological system and propose a set of corresponding indicators to monitor freshwater ecosystem health and to highlight priorities for management. We demonstrate an application of this new framework -the Freshwater Health Index (FHI) - in the Dongjiang River Basin in southern China, where stakeholders are addressing multiple and conflicting freshwater demands. By combining empirical and modeled datasets with surveys to gauge stakeholders' preferences and elicit expert information about governance mechanisms, the FHI helps stakeholders understand the status of freshwater ecosystems in their basin, how ecosystems are being manipulated to enhance or decrease water-related services, and how well the existing water resource management regime is equipped to govern these dynamics over time. This framework helps to operationalize a truly integrated approach to water resource management by recognizing the interplay between governance, stakeholders, freshwater ecosystems and the services they provide.

International climate negotiations have stressed the importance of considering emissions from forest degradation under the planned REDD+ (Reducing Emissions from Deforestation and forest Degradation + enhancing forest carbon stocks) mechanism. However, most research, pilot-REDD+ projects and carbon certification agencies have focused on deforestation and there appears to be a gap in knowledge on complex mosaic landscapes containing degraded forests, smallholder agriculture, agroforestry and plantations. In this paper we therefore review current research on how avoided forest degradation may affect emissions of greenhouse gases (GHG) and expected co-benefits in terms of biodiversity and livelihoods. There are still high uncertainties in measuring and monitoring emissions of carbon and other GHG from mosaic landscapes with forest degradation since most research has focused on binary analyses of forest vs. deforested land. Studies on the impacts of forest degradation on biodiversity contain mixed results and there is little empirical evidence on the influence of REDD+ on local livelihoods and tenure security, partly due to the lack of actual payment schemes. Governance structures are also more complex in landscapes with degraded forests as there are often multiple owners and types of rights to land and trees. Recent technological advances in remote sensing have improved estimation of carbon stock changes but establishment of historic reference levels is still challenged by the availability of sensor systems and ground measurements during the reference period. The inclusion of forest degradation in REDD+ calls for a range of new research efforts to enhance our knowledge of how to assess the impacts of avoided forest degradation. A first step will be to ensure that complex mosaic landscapes can be recognised under REDD+ on their own merits.

La répartition biaisée des avantages tirés des ressources naturelles peut alimenter l'exclusion sociale et les conflits, menaçant la durabilité. Cet article analyse comment les droits de propriété des groupes d'utilisateurs pour récolter des produits forestiers affectent la distribution des avantages de ces produits au sein des groupes d'utilisateurs. Nous soutenons que les groupes ayant des droits de récolte reconnus partagent les avantages plus équitablement entre les membres du groupe que les groupes sans ces droits. Nous testons cet argument avec les données de 350 groupes d'utilisateurs des forêts dans 14 pays en développement. Nos résultats suggèrent que la sécurisation des droits de récolte pour les groupes d'utilisateurs locaux peut contribuer à un partage plus égal des avantages, en particulier dans les groupes ethniquement homogènes. La distribución sesgada de los beneficios de los recursos naturales puede alimentar la exclusión social y los conflictos, amenazando la sostenibilidad. Este documento analiza cómo los derechos de propiedad de los grupos de usuarios para cosechar productos forestales afectan la distribución de los beneficios de esos productos dentro de los grupos de usuarios. Argumentamos que los grupos con derechos de cosecha reconocidos comparten los beneficios más equitativamente entre los miembros del grupo que los grupos sin tales derechos. Probamos este argumento con datos de 350 grupos de usuarios forestales en 14 países en desarrollo. Nuestros resultados sugieren que asegurar los derechos de cosecha para los grupos de usuarios locales puede contribuir a una distribución más equitativa de los beneficios, especialmente en grupos étnicamente homogéneos. Skewed distributions of benefits from natural resources can fuel social exclusion and conflict, threatening sustainability. This paper analyzes how user-group property rights to harvest forest products affect the distribution of benefits from those products within user groups. We argue that groups with recognized harvesting rights share benefits more equally among group members than groups without such rights. We test this argument with data from 350 forest user groups in 14 developing countries. Our results suggest that securing harvesting rights for local user groups can contribute to more equal benefit sharing, especially in ethnically homogenous groups. يمكن للتوزيعات المنحرفة للمنافع من الموارد الطبيعية أن تغذي الاستبعاد الاجتماعي والصراع، مما يهدد الاستدامة. تحلل هذه الورقة كيف تؤثر حقوق ملكية مجموعة المستخدمين لحصاد منتجات الغابات على توزيع الفوائد من تلك المنتجات داخل مجموعات المستخدمين. ونجادل بأن المجموعات التي تتمتع بحقوق حصاد معترف بها تتقاسم الفوائد بالتساوي بين أعضاء المجموعة أكثر من المجموعات التي لا تتمتع بهذه الحقوق. نحن نختبر هذه الحجة ببيانات من 350 مجموعة من مستخدمي الغابات في 14 دولة نامية. تشير نتائجنا إلى أن تأمين حقوق الحصاد لمجموعات المستخدمين المحليين يمكن أن يساهم في تقاسم المنافع بشكل أكثر مساواة، خاصة في المجموعات المتجانسة عرقيًا.

Surface water contamination can often be reduced by passing runoff water through perennial grass filters. Research was conducted in 2006 to 2008 to evaluate the size of cool season grass filters consisting primarily of tall fescue (Festuca arundinacea Schreb) with some orchard grass (Dactylis glomerata L.) relative to drainage area size in reducing runoff sediment and phosphorus (P). The soil was Pohocco silt loam Typic Eutro- chrepts with a median slope of 5.5 %. The grass filters occupying 1.1 and 4.3 % of the plot area were compared with no filter with four replica- tions. The filters were planted in the V-shaped plot outlets which were 3.7×11.0 m in size. The filter effect on sediment and P concentration was deter- mined from four natural runoff events when nearly all plots had runoff. Filter effect on runoff volume and contaminant load was determined using total runoff and composites of samples collected from 12 runoff events. Sediment concentration was re- duced by 25 %w ith filters compared with no filter (from 1.10 to 1.47 gL −1 ), but P concentration was not affected. The 1.1 and 4.3 % filters, respective- ly, compared with having no grass filter, reduced: runoff volume by 54 and 79 %; sediment load by 67 and 84 % (357 to 58 kgha −1 ); total P load by 68 and 76 %( 0.58 to 0.14 kgha −1 ); particulate P (PP) load by 66 and 82 %( 0.39 to 0.07 kgha −1 ); and dissolved reactive P (DRP) load by 73 and 66 % (0.2 to 0.07 kgha −1 ), respectfully. A snowmelt runoff event had 56 % greater DRP concentration compared with rainfall-induced runoff events. Grass filters re- duced sediment and P load largely by reducing runoff volume rather than reducing concentration. Well- designed and well-placed grass filters that occupy 1.0 to 1.5 % of the drainage area and intercept a uniform