Tree retention practices in boreal forests: what kind of future landscapes are we creating?

Tree retention practices promoting biodiversity may reshape future boreal forest production landscapes. Using the Heureka system, scenarios of 0%, 5%, and 20% retained patches at the stand level were projected over 200 years in a 533 ha boreal landscape. Visualizations of future forest states at a landscape scale and a more detailed scale were made based on the projections. The no retention results in no forest >120 years old, and no large trees (diameter at breast height >40 cm for conifers and >35 cm for broadleaved trees) 100 years from now. With retention levels of 5% and 20%, the area of old forest will comprise 7% and 19% of the total area, respectively. The average number of large trees per ha will be 4 and 13, respectively. Deadwood volumes will be 2.5 times higher at 5% retention and 4 times higher at 20% retention compared to no retention. Landscape visualizations indicate that retention patches covering 5% will marginally modify the visual impression, compared to clear-cuts, while 20% cover will create a much more varied landscape. We conclude that the retention approach is essential for restoring natural conditions. Landscape transformation will be slow and depend on starting conditions and retention levels.

[1]  L. Gustafsson,et al.  Tree retention as a conservation measure in clear-cut forests of northern Europe: a review of ecological consequences , 2010 .

[2]  A. Lõhmus,et al.  Tree cavities in forests The broad distribution pattern of a keystone structure for biodiversity , 2011 .

[3]  Juha Siitonen,et al.  Forest management, coarse woody debris and saproxylic organisms: Fennoscandian boreal forests as an example , 2001 .

[4]  Jörg Müller,et al.  A review of habitat thresholds for dead wood: a baseline for management recommendations in European forests , 2010, European Journal of Forest Research.

[5]  A. Kiviste,et al.  Preadaptation and spatial effects on retention-tree survival in cut areas in Estonia , 2008 .

[6]  L. Gustafsson,et al.  Fine-scale conservation planning outside of reserves: Cost-effective selection of retention patches at final harvest , 2011 .

[7]  L. Gustafsson,et al.  Retention patches as potential refugia for bryophytes and lichens in managed forest landscapes , 2009 .

[8]  N. Fahlvik,et al.  Evaluation of growth functions used in the Swedish Forest Planning System Heureka , 2014 .

[9]  Per‐Anders Esseen,et al.  Eighteen years of tree mortality and structural change in an experimentally fragmented Norway spruce forest , 2007 .

[10]  Richard H. W. Bradshaw,et al.  Challenges of ecological restoration: Lessons from forests in northern Europe , 2013 .

[11]  James P. Kimmins,et al.  The ecological effects of clear-cutting , 1993 .

[12]  I. Vanha-Majamaa,et al.  Immediate tree uprooting after retention-felling in a coniferous boreal forest in Fennoscandia , 2006 .

[13]  P. Leitão,et al.  Drivers of forest harvesting intensity patterns in Europe , 2014 .

[14]  John Nelson,et al.  Application of texture mapping to generate and communicate the visual impacts of partial retention systems in boreal forests , 2006 .

[15]  R. Ribe.  In-stand scenic beauty of variable retention harvests and mature forests in the U.S. Pacific Northwest: the effects of basal area, density, retention pattern and down wood. , 2009, Journal of environmental management.

[16]  S. Nilsson,et al.  Densities of large living and dead trees in old-growth temperate and boreal forests , 2002 .

[17]  Ljusk Ola Eriksson,et al.  The Heureka Forestry Decision Support System: An Overview , 2011, Math. Comput. For. Nat. Resour. Sci..

[18]  Lenore Fahrig,et al.  Targets for maintenance of dead wood for biodiversity conservation based on extinction thresholds , 2006 .

[19]  Erkki Tomppo,et al.  A report to the food and agriculture organization of the united nations (FAO) in support of sampling study for National Forestry Resources Monitoring and Assessment (NAFORMA) in Tanzania , 2010 .

[20]  Eeva Karjalainen,et al.  Visualization in forest landscape preference research: a Finnish perspective , 2002 .

[21]  P. Wikberg.  Occurrence, morphology and growth of understory saplings in Swedish forests , 2004 .

[22]  Y. Paillet,et al.  Biodiversity Differences between Managed and Unmanaged Forests: Meta‐Analysis of Species Richness in Europe , 2010, Conservation biology : the journal of the Society for Conservation Biology.

[23]  L. Gustafsson,et al.  Retention Forestry to Maintain Multifunctional Forests: A World Perspective , 2012 .

[24]  Jogeir N. Stokland,et al.  Biodiversity in dead wood. , 2012 .

[25]  E. Karjalainen,et al.  Scenic Impacts of Retention Trees in Clear-cutting Areas , 2004 .

[26]  L. Gustafsson,et al.  Retaining trees for conservation at clearcutting has increased structural diversity in young Swedish production forests , 2013 .

[27]  Per Linder,et al.  Structural changes in three mid-boreal Swedish forest landscapes, 1885–1996 , 1998 .

[28]  Steve M. Read,et al.  Variable retention silviculture in Tasmania's wet forests: ecological rationale, adaptive management and synthesis of biodiversity benefits , 2011 .

[29]  L. Schön.  Agriculture and Forestry in Sweden Since 1900 , 2012, The Journal of Economic History.

[30]  Terrence Bush.  Biodiversity and Sectoral Responsibility in the Development of Swedish Forestry Policy, 1988–1993 , 2010, Scandinavian journal of history.

[31]  United Kingdom,et al.  GLOBAL FOREST RESOURCES ASSESSMENT 2005 , 2005 .

[32]  Jürgen Bauhus,et al.  Silviculture for old-growth attributes , 2009 .

[33]  Jeffrey L. Moffett,et al.  Landscape management through integration of existing tools and emerging technologies , 1998 .

[34]  G. Ståhl,et al.  A Three-step Approach for Modelling Tree Mortality in Swedish Forests , 2001 .

[35]  Charles B. Halpern,et al.  Level and pattern of overstory retention interact to shape long-term responses of understories to timber harvest. , 2012, Ecological applications : a publication of the Ecological Society of America.

[36]  L. Gustafsson,et al.  A major shift to the retention approach for forestry can help resolve some global forest sustainability issues , 2012 .

[37]  L. Gustafsson,et al.  Can retention forestry help conserve biodiversity? A meta-analysis , 2014, The Journal of applied ecology.

[38]  E. Karjalainen,et al.  The visual effect of felling on small- and medium-scale landscapes in north-eastern Finland , 1999 .

[39]  Charles B. Halpern,et al.  Variable-retention harvests in the Pacific Northwest: A review of short-term findings from the DEMO study , 2009 .

[40]  A. Lõhmus,et al.  Effectiveness of solitary retention trees for conserving epiphytes : differential short-term responses of bryophytes and lichens , 2006 .

[41]  María Vanessa Lencinas,et al.  Timber management with variable retention in Nothofagus pumilio forests of Southern Patagonia , 2009 .

[42]  Short-term response of the herbaceous layer within leave patches after harvest , 2009 .

[43]  Torbjörn Josefsson,et al.  The history of clear-cutting in northern Sweden – Driving forces and myths in boreal silviculture , 2013 .

[44]  K. Rogers.  A Visual Effect , 2016 .

[45]  L. H. Frivold,et al.  Public preferences for forest structures: a review of quantitative surveys from Finland, Norway and Sweden. , 2008 .