Intensive forest biomass harvesting and biodiversity in Canada: A summary of relevant issues

Abstract

Increasing interest in renewable fuels inspired a three-day workshop in Toronto in February 2008, entitled: The Scientific Foundation for Sustainable Forest Biomass Harvesting Guidelines and Policy. In this paper, we summarized the biodiversity-focused content of the workshop, including potential implications of intensification of biomass removal on biodiversity, knowledge gaps identified by workshop participants, and implications for policy development. Woody debris represents an important habitat resource for a wide variety of forest organisms, and the presence and continued supply of fresh to highly decayed dead wood represents a key concern in managed forest systems. A key challenge in sustainable forests management is to determine to what extent biomass harvests can increase fibre use while sustaining biodiversity, its functions, and the broad suite of ecosystem services that it provides. For knowledge-based planning and policy development, researchers must provide complex information to policy-makers and forest managers in a clear, effective way. In particular, full life-cycle analysis of intensive forest biomass harvesting taking into account environmental consequences is needed to inform sound evidence-based policy and decision-making. In the absence of complete scientific information, forest managers and decision-makers are well-advised to proceed with caution within a well-developed adaptive management framework.

Significant and persistent impact of timber harvesting on soil microbial communities in Northern coniferous forests

“…These two properties regulate many important soil processes, including temperature, water regime, gas exchange, nutrient availability, carbon sequestration and energy supply (Powers et al, 2005), and ultimately control a forest's productivity and functionality (Worrell and Hampson, 1997). Currently, there is a demand to maximize OM removal from forests, in order to divert previously unused OM to biofuel production, but the effect on long-term soil productivity (LTSP), biodiversity and ecosystem services is poorly understood (Berch et al, 2011). Increased biomass removal as performed during whole-tree harvesting and site preparation for planting may affect the microbial communities and reduce forest productivity in the long term (Wei et al, 2000;Walmsley et al, 2009).…”

Comparative effects of full-tree and tree-length shelterwood harvesting on residual tree damage and coarse woody debris volume in the Great Lakes – St. Lawrence forest

“…Aside from concerns related to potential damage to residual trees during FT harvest, concerns have been raised about potential effects on nutrient balances and recruitment of CWD, regardless of silvicultural system (Berch et al 2011, Puddister et al 2011. Retention of coarse woody material is an important part of sustaining forest productivity and biodiversity (Spies 1998, Shields et al 2007, Vanderwel et al 2009, OMNR 2010, though quantities vary considerably (Fig.. 4).…”

“…Skidding of large limbed trees could (1) damage more residual trees, (2) disturb a greater proportion of the advanced regeneration both within and beyond skid trails, and (3) increase disturbance of the soil surface. Moreover, concerns have been expressed about the effect of fulltree logging on productivity of the stand for future harvests and coarse woody debris (CWD) loads, and the effect of reduced CWD on wildlife habitat and species diversity (Berch et al 2011, Puddister et al 2011.…”

Modelling deadwood supply for biodiversity conservation: Considerations, challenges and recommendations

“…Studies often identify a minimum diameter to consider, and this can range widely depending upon project objectives (e.g., Garber et al 2005, Russell et al 2006. To examine the potential effects of biomass removals on the full suite of wood-inhabiting biota, all sizes of deadwood need to be considered (Berch et al 2011). Piece size is also important because there is some evidence of an inverse relationship between decay rate and diameter size for many tree species (Huggard and Kremsater 2007).…”

“…The importance of sustainable biomass removal for bioenergy has been widely discussed by governments, NGOs, forest managers and researchers in recent years (Roser et al 2008, Berch et al 2011, Dagg et al 2011, Mainville 2011, Roach and Berch 2014. Research on soil and tree productivity to assess sustainability in relation to biomass removal has been going on for over three decades in Canada (Titus et al 2010), but questions of sustainability related to biodiversity conservation have had far less attention.…”