Update 2019: More formal implementation of the triad system is a key component of the Lahey Report. View:
– An Independent Review of Forest Practices in Nova Scotia: Executive Summary, Conclusions and Recommendations
By William Lahey. 82 pages
– An Independent Review of Forest Practices in Nova Scotia: Addendum.
In particular, view Ch 13 Balanced Forestry and the Triad, by Robert Seymour, pp 61-86
Glossary Definitions in Nova Scotia’s Code of Forest Practice for levels of management intensity (Aug 2012):
Forest Conservation Reserve
Reserve lands which meet biodiversity conservation goals through preservation of natural conditions and processes and are specifically designated through legislation, legal and policy mechanisms.
Forests where natural patterns and ecosystem functioning are maintained while managing for multiple resource uses. These lands include those protected from the ravages of fire and insects. Natural regeneration is used to provide the next forest as part of natural succession. Natural forest characteristics are maintained throughout the rotation including speciesdiversity (over and under story), stand structures (coarse woody debris and snags), patchsize (indicative of the natural disturbance), and site and soil productivity.
Forests where tree growth is maximized through management inputs focused on increasing fibre production. These forests are protected from fire, insects and competing vegetation. Fibre based forest management generally eliminates or reduces the duration of development processes, particularly those associated with long rotation old forest conditions. Management practices often result in non-natural succession.
A process in which natural forest landscapes are replaced by other land uses, affecting natural habitats and biodiversity.
More detailed descriptions of these management levels are given in Appendix 11 of A Procedural Guide For Ecological Landscape Analysis (NSDNR 2008)
Comment: Although not cited as “triad zoning” in the Nova Scotia documents, the definitions for forested areas (Forest Conservation Reserve, Extensive Forests and Intensive Forests) are consistent with definitions and descriptions of triad zoning given in the literature e.g., in Tittler, R. et al., 2015. Maximizing Conservation and Production with Intensive Forest Management: It’s All About Location. Environmental Management 56:1104–1117; Seymour, R.S., and M.L. Hunter Jr. 1992. New forestry in eastern spruce-fir forests : Principles and applications to Maine. Maine Agricultural and Forest Experiment Station Miscellaneous Publication 716.
In triad zoning, part of the forest is set aside for protected areas, with biodiversity conservation as the main goal; another part is designated as intensive management, with timber production as the main goal; and the rest of the forest is designated as extensive management, where an attempt is made to balance the needs of all forest users through less-intensive forestry practices (Seymour and Hunter 1992). In the protected areas, there is no timber extraction, and rather a focus on conservation and associated low-impact recreational use. In intensive management areas, various silvicultural techniques are applied to maximize timber production. Intensive management areas include plantations, often of hybrid and fast-growing tree species as well as of native species, but may also include other techniques such as thinning. In extensive management areas, timber extraction practices are often designed to mimic the processes and patterns created by natural disturbances, thus allowing for extraction while also trying to maintain a more-or-less natural forest… any large-scale spatial scenario should ideally maximize the amount of old growth forest, which is generally rarified by forestry practices that harvest trees at maturity (i.e., between 60 and 100 years of age in Quebec)
– Tittler, R. et al. (2015)
The major objective behind such zoning is to
…allow for more conservation without sacrificing the viability of the forest industry…In general, a trend is emerging in favor of concentrating intensive rather than spreading out less intensive anthropogenic disturbances over a larger area. For example, for the same amount of housing, clustered housing is not as detrimental to native biodiversity as urban sprawl (Gagne´ and Fahrig 2010a, b). This also holds for road development. Since roads fragment habitat, keeping animals from accessing resources on the other side and potentially leading to population isolation (e.g., Keller and Largiade` r 2003), fewer large, high-traffic roads leave a more intact landscape than more small, dispersed roads (Jaeger et al. 2007), thus reducing road effects on native biodiversity.
– R. Tittler et al. 2012. Concentrating anthropogenic disturbance to balance ecological and
economic values: applications to forest management. Ecological Applications, 22(4), 2012, pp. 1268–1277
See also: Principles of Ecological Forestry, Chapter 2 by Robert S. Seymour and Malcolm L. Hunter Jr., in Maintaining Biodiversity in Forest Ecosystems, Publisher: Cambridge Univ Press, Editors: M.L. Hunter, pp.22-61, Triad forestry is discussed on pages 52-57.