Ecosystem Management in the Boreal Forest

Chapter 11 : Ecosystem Management of Québec's Northern Clay Belt Spruce Forest

Chapter 11 Ecosystem Management of Québec’s Northern Clay Belt Spruce Forest Managing the Forest… and Especially the Soils Martin Simard, Nicolas Lecomte, Yves Bergeron, Pierre Y. Bernier, and David Paré  We thankfully acknowledge the funding agencies that have supported the work presented in this chapter: the Network for Centres of Excellence in Sustainable Forest Management, the Natural Sciences and Engineering Research Council of Canada, the Fonds québécois de recherche sur la nature et les technologies, the Fonds d’action québécois pour le développement durable, the Programme de mise en valeur du milieu forestier (volet 1) of the Ministère des Ressources naturelles et de la Faune du Québec, Canada Economic Development, Natural Resources Canada, the industrial partners of the NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, and the Université du Québec en Abitibi-Témiscamingue. We also wish to thank Nicole Fenton, Martin Lavoie, Sonia Légaré, and Annie Belleau for their contribution to this work through insightful and productive discussions. Finally, we thank Pamela Cheers, Benoit Arsenault, and Isabelle Lamarre of Natural Resources Canada for the linguistic revision of the manuscript. Photos on this page were graciously provided by Martin Simard. 1. Introduction..................................................................................... 259 2. Regional Context............................................................................. 259 3. Disturbance Regime. ........................................................................ 261 3.1. Fire Frequency........................................................................... 261 3.2. Soil Burn Severity...................................................................... 261 3.3. Insect Outbreaks and Windthrow.............................................. 263 4. Forest Dynamics............................................................................... 263 4.1. Paludification. ............................................................................ 263 4.2. Forest Structure and Succession................................................ 264 4.3. Understory Succession. .............................................................. 269 4.4. Forest Productivity. .................................................................... 269 4.5. The Cohort Approach. ............................................................... 272 5. Proposed Ecosystem Management Strategy.................................. 272 5.1. Comparison of Natural Disturbances to Current . Silvicultural Practices................................................................. 272 5.2. Creating or Maintaining Late-Successional Structures . Using Uneven-Aged Silviculture................................................. 276 5.3. Creating Early-Successional Structures . Using Even-Aged Silviculture..................................................... 276 5.4. Targeting the Right Stands to Be Treated.................................. 278 5.5. Maintaining a Balanced Forest Mosaic. ...................................... 280 6. Conclusion. ....................................................................................... 282 References............................................................................................. 283 1. Introduction Forests of the northern Clay Belt of Québec and Ontario (Canada) are dominated by black spruce forests. The natural landscape and stand dynamics of these forests have been widely studied (Bergeron et al. 2002; Lefort et al. 2002; Gauthier et al. 2004; Carleton and Maycock 1978, 1980). Many studies have documented disturbance (Carcaillet et al. 2001; Bergeron et al. 2004) and stand dynamics (Gauthier et al. 2000; Harper et al. 2003; Lecomte et al. 2006a), while others have compared the effects of natural disturbances with those of silvicultural treatments (Nguyen-Xuan et al. 2000; Simard et al. 2001; Fenton and Bergeron 2007; Fenton et al., chapter 15). Recent studies have focused on the paludification process (i.e. the gradual accumulation of soil organic matter ultimately leading to the development of a peatland) and its effects on forest productivity and biodiversity. Findings from these studies require us to revisit the forest management strategy previously proposed for the black spruce forest of northwestern Québec (Bergeron et al. 1999). Forests in this region are managed commercially for their timber. Accounting for natural dynamics of these forests could help forest managers in maintaining forest productivity without compromising biodiversity. In particular, three characteristics of the regional forest dynamics must be taken into account for the successful implementation of an ecosystem management strategy. First, paludification is a pervasive and widespread phenomenon that has important consequences for the diversity and productivity of stands and landscapes. Second, soil burn severity is highly variable and affects tree regeneration, forest productivity and succession, and biodiversity. Finally, most stands show little or no tree species replacement during succession, and as a result, changes in stand structure are of particular importance. As we demonstrate in this chapter, ignoring these properties of natural forest dynamics can lead to a decrease in both biodiversity and forest productivity. In this chapter, we describe our current understanding of natural disturbance dynamics and long-term post-fire stand succession in Québec’s western black spruce–feather moss bioclimatic subdomain. Building on this foundation, we propose a new ecosystem management strategy that relies on silvicultural treatments whose effects are similar to those of the region’s natural disturbance regime. We conclude by discussing societal choices regarding the regional forest management, considering the historical variability of forest and disturbance dynamics, and the global consequences of decisions taken at the regional level. 2. Regional Context The study area (49°00′–50°30′N; 78°30′–79...