The Structure of Mixed Species Stands in the ICHmw SubzonesStand Structure TypesStand structure types were derived by first grouping similar tree species into guilds and then describing the composition of individual stands according to guilds rather than individual species.In this context, a guild is a group of species that play similar roles in stand development. The main characteristics used to define the guilds were height-growth rate, height-growth pattern and shade tolerance. The species of the ICHmw subzones have been classified into four guilds based on growth characteristics exhibited in those subzones. The species composition of stands can now be expressed in terms of these four guilds, rather than the numerous individual species. For example, a stand in which 80% or more of the basal area was comprised of western redcedar and western hemlock would be considered a VC stand structure type because Cw and Hw are members of the VC guild. In more complex stands, there will be cases where no single guild contributes more than 80% of the total basal area. These stands might be described by the two leading guilds if those two together form more than 80% of the basal area. A mixture of intolerant conifers (IC) and intolerant broadleaves (IB), for example, would be denoted as an IC+IB stand structure type. The proportions of guild composition can be indicated with the less-than (<), greater-than (>) and equality (=)symbols. For example, IC=IB indicates a stand type in which the proportions of intolerant conifers and intolerant broadleaves are approximately equal. In very complex stands, even the two leading guilds may not make up 80% of the basal area. For now, these stands will be described as a Complex Mix (CMix). The stands described in this report fall into six different stand types: 1. VC Mixtures of Very Tolerant Conifers 2. IB+VC Mixtures of Intolerant Broadleaves and Very Tolerant Conifers 3. IC+IB Mixtures of Intolerant Conifers and Intolerant Broadleaves 4. IC+TC Mixtures of Intolerant Conifers and Tolerant Conifers 5. IC+VC Mixtures of Intolerant Conifers and Very Tolerant Conifers 6. CMix Complex Mixtures
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Return to: The Structure of Mixed Species Stands in the ICH Biogeoclimatic Zone
Last Modified: 2001 01 24. Ministry contact: Catherine
Bealle Statland |
