396 research outputs found

    Determinants and Tools to Evaluate the Ecological Sustainability of Using Forest Biomass as an Alternative Energy Source

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    Forest biomass, the most ancient of fuels, is again in the center of renewable energy production. This chapter provides an introductory view of the main factors that condition the ecological sustainability of this energy source. The basic concepts of ecological sustainability, ecological rotation, and ecological thresholds (among others) are presented. The state of the art on approaches to assess the sustainability of forest biomass production for heat and electricity is discussed, and tools available for decision-makers to evaluate the sustainability of forest biomass production and management are described. This chapter then describes the main advantages and drawbacks of forest certification, growth and yield tables, and ecological models in relationship to their use in sustainable forest management for biomass and energy production

    Maintaining Ecosystem Function by Restoring Forest Biodiversity – Reviewing Decision-Support Tools that link Biology, Hydrology and Geochemistry

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    Not all forest models are applicable to a meta-modelling approach. Hence, the objective of the research presented here was to identify and compare the available forest models already being used in research, and to evaluate their suitability for use as decision-support tools in designing successful restoration plans to bring forest biodiversity and function back to sites disturbed by industrial activities (mining in particular).This work was conducted with funding generously supplied by Total E&P Canada Ltd., Calgary, Alberta, Canada

    Douglas-fir radial growth in interior British Columbia can be linked to long-term oscillations in Pacific and Atlantic sea surface temperatures

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    A major problem in modern dendrochronology is that the methods traditionally used for linking tree ring growth data to climate records are not well suited to reconstructing low-frequency climatic variations. In this study, we explored the alternative Ensemble Empirical Mode Decomposition to detrend tree-ring records and to extract climate signals without removing low-frequency information. Tree cores of Pseudotsuga menziesii var. glauca (Mayr.) Franco were examined in a semi-arid forest in southern interior British Columbia, western Canada. Ring width data were decomposed into five oscillatory components (intrinsic mode functions, IMFs) of increasingly longer periodicities. IMF 1 was considered white noise, IMF 2 was used to create the first diameter growth index (DGI-1), IMF 3 and IMF 4 were combined to create the second diameter growth index (DGI-2), whereas IMF 5 and the residual term together were considered as the trend term. The highest significant cross-correlations between DGI-1 and the NAOAugust, NIÑO12May, and PDOJanuary indices were found at 1-year lags. DGI-2 had positive and persistent correlations with NAOJune and PDOMay at 0 to 3 years lags, and with NAOMay at 2 and 3 years lags. Our results indicate that periods of slow growth in the tree ring record matched periods of drought in the North American Pacific Northwest. Such water limiting conditions are likely caused by oscillatory patterns in the Pacific Ocean sea surface temperatures that influence precipitation in the Pacific Northwest. These drought events are likely exacerbated by changes in winter precipitation (snowpack) related to oscillations of the Atlantic Ocean sea surface temperatures, highlighting the ecological effects of both oceans on terrestrial ecosystems. Such relationships could not be easily found by traditional tree-ring analysis that remove some of the low-frequency signal, and therefore we suggest Ensemble Empirical Mode Decomposition as an additional tool to establishing tree growth-climate relationships.Juan A. Blanco was supported by grants from the Spanish Ministry of Economy and Competitiveness (AGL2012-33465), a Marie Curie Action fellowship from the European Commission (CIG-2012-326718-ECOPYREN3), and a Campus Iberus grant for mobility of research staff

    Resilience assessment of lowland plantations using an ecosystem modeling approach

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    As afforestation programs of former farmlands take hold in Taiwan to achieve a variety of ecological and socio-economic values, it is becoming necessary to define best forest management. Hence, we simulated mixed stands of Cinnamomum camphora and Fraxinus griffithii planted through a gradient of soil fertility and varying camphor/ash density ratios, but maintaining a fixed total stand density of 1500 trees ha −1 . Total stand productivity was slightly lower in mixed stands than the combination of both monocultures in rich and poor sites. Maximum negative yield surpluses for 50-year old stands were 7 Mg ha −1 and 6 Mg ha −1 for rich and poor sites with a 1:1 camphor laurel/ash ratios. Maximum stand woody biomass in rich sites was reached in camphor laurel monocultures (120 Mg ha −1 ) and in poor sites for Himalayan ash monocultures (58 Mg ha −1 ). However, for medium-quality sites, a small yield surplus (11 Mg ha −1 ) was estimated coinciding with a maximum stand woody biomass of 95 Mg ha −1 for a 1:1 camphor laurel/ash density ratio. From an ecological resilience point of view, rotation length was more important than stand composition. Long rotations (100 years) could improve soil conditions in poor sites. In rich sites, short rotations (50 years) should be avoided to reduce risks or fertility loss.Yueh-Hsin Lo was funded by the Spanish Ministry of Economy and Competitiveness (Ref. AGL2012-33465). Juan A. Blanco was funded through a “Ramón y Cajal” contract (Ref. RYC-2011-08082) and a Marie Curie Action (Ref. CIG-2012-326718-ECOPYREN3). Shih-Chieh Chang was given a grant by the Ministry of Science and Technology (Ref. NSC 102-2621-M-259-005
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