Biological and Envrionmental Sustainability
Authored By: D. Mead, D. Foster
Whereas sustained yield focuses on the product flow from a forest, biological and environmental sustainability is more encompassing as it includes a wider range of forest ecosystem benefits. This is dealt with in more depth in the Environmental Sustainability section and is also covered elsewhere (Richardson and others 2002; Mead 2005). From the point of utilization of biomass for energy the following points directly impact silviculture:
The removal of high amounts of nutrient-rich foliage can potentially reduce soil fertility, which could be a problem on less fertile sites. To reduce the potential impact on soil fertility, it is preferable to leave most foliage on site. This can be achieved by harvesting after leaf fall, or leaving material to dry on site so that some leaves are shed, or by not removing the upper parts of the tree crown. Returning ash, after combustion, to the site is also a good alternative for maintaining soil fertility, except for nitrogen. Soil or foliage analysis on poorer soils may indicate that supplemental fertilization is required to maintain fertility and sustainability. Harvesting operations should be designed to minimize damage to soil physical properties. Avoid harvesting very large and old trees since these are increasing rare structures in the landscape and are important for biodiversity. The use of dead wood, particulary larger snags and logs, should be restricted since they can be especially valuable for biodiversity. Ensure there are adequate riparian strips where there will be minimal biomass harvesting (see Designing Low-Impact Operations).
- Mead, D. J. 2005. Forests for energy and the role of planted trees. Critical reviews in plant sciences. 24: 407-421.
- Richardson, J.; Bjorheden, R.; Hakkila, P.; Lowe, A.T.; and Smith, C.T. 2002. Bioenergy from sustainable forestry: guiding principles and practice. Dordrecht, The Netherlands: Kluwer Academic Publishers. 344 p.
