1. Agricultural intensification is one of the main causes of biodiversity loss world-wide. The inclusion of semi-natural features in agricultural landscapes is suggested as a means of enhancing farm biodiversity, but this practice may have potential negative effects on yield production. Moreover, little evidence exists for effects of semi-natural features on other components of biodiversity, such as functional diversity. Yet this could provide a more comprehensive understanding of biodiversity-productivity trade-offs. 2. Here, we report the effects of semi-natural woody vegetation on taxonomic and functional diversity, and biomass production of herbaceous species at the field and farm scales by sampling 50 fields, ranging from 0 to 90% woody vegetation cover, on nine similarly managed farms in central-western Spain. 3. We found significant differences in herbaceous species richness among farms. Both taxonomic and functional b-diversity exhibited significant negative relationships with herbage production, highlighting the trade-off between biodiversity and productivity in these agroecosystems. 4. Woody vegetation cover had a significant negative relationship with biomass production and a unimodal relationship with species richness at the field scale. At high values of woody vegetation cover, species richness and functional diversity indices were decoupled, suggesting that at this extreme of the woody vegetation gradient, only herbaceous species with contrasting trait values were present. Our results showed both convergent and divergent patterns of trait values, suggesting that different assembly processes are acting concurrently along the gradient of woody vegetation. 5. Synthesis and applications. Our result indicates that management of woody vegetation may indeed increase both taxonomic and functional diversity, but this may come at the expense of key ecosystem services or other management goals, namely herbage production. Optimization of the trade-off between herbage diversity and productivity can be reached with a woody vegetation cover of c. 30% at the field scale.
In 2009, the European Union (EU) Renewable Energy Directive (RED) mandated that 20% of the EU's fi nal energy consumption consist of renewable sources by 2020, and included sustainability criteria for liquid biofuels. Discussions around extending criteria to solid and gaseous biomass, including wood pellets, have been ongoing. Continued investment in forest bioenergy feedstock production is partly dependent on the stability of global market demand and the economic viability of feedstock production and trade. For trans-boundary governance mechanisms such as the RED to be effi cient, a proper assessment of the specifi c forest and land policy contexts of wood pellet exporters that the mechanism will affect, such as Canada, the USA, and Russia, is crucial. This paper builds on sustainability criteria for biodiversity protection and assurance of sustainable forest management (SFM) for woody biomass that are currently under discussion for inclusion in the RED and compares them with national and local regulations of those three countries. This illustrates potential challenges in the establishment of sustainability criteria related to: differences in land defi nitions, delineation and reporting systems; lack of a uniform defi nitional paradigm for SFM; and diffi culties in establishing effi cient monitoring/auditing systems. Regulators wanting to implement supra-national sustainability schemes such as the EU RED need to be aware of challenges that such schemes carry and make efforts to reduce or eliminate pitfalls. There is also a need to assess the aggregated effects of these various tools, and a need for communication, collaboration and outreach among stakeholders.
In the managed forest of Canada, forest fires are actively suppressed through efficient initial attack capability; however, the impact of different factors on the suppression success remains to be understood. The aim of this paper was to analyze the influence of operational suppression objectives (fire detection, initial attack, and fire control) along with fire intensity, fuel type, fire ignition cause, year, workload, and homogeneous fire regime zones on the achievement of the fire suppression objective (fire < 3 ha) using the Forest Fire Protection Agency of Quebec (SOPFEU) as a case study. The overall success of the suppression objective was very high (88%) over the study period (1994–2015). Both detection and control had significant effects on the suppression success through their interaction with fuel type, ignition cause, fire intensity, and zone variables. When the suppression objective was not achieved, final fire size was influenced by control, fuel type, fire intensity, and zone. The paper highlights the importance of the operational objectives and of regional differences for both fire suppression success and final fire size. Our results can help forest fire protection agencies to better understand their wildland fire suppression systems for a better adaptation to the upcoming fire regime changes.
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