(a) growing trees continuously
(b) providing forest or wilderness oriented recreation
(c) producing forage for livestock and wildlife
(d) conservation of wilderness
(e) other forest uses.
This chapter reports primarily on inventory information related to growing trees for timber production. Chapters 4, 5 and 6 provide information relating to issues (b), (c), (d) and (e).
Quality and quantity of inventory information vary from one area to another, primarily depending on who owns and manages the land. Land ownership and management are summarized for the province and each forest region in Chapter 1, Figures 1.2-1.8.
Provincial Crown land makes up most (94.7%) of the province. Land administered by the Ministry of Forests, including TFLs,[24] makes up most of the Crown land (91.5% of the Crown land, 86.7% of the province). Crown land administered by the Ministry of Forests, often in cooperation with other ministries is either in timber supply areas (78.3% of the province), tree farm licences (7.9% of the province) or various other tenures, including woodlot licences (0.5% of the province).
Figure 3.1 shows the distribution of TSAs in the province. Figure 3.2 a, b and c shows the distribution of TFLs for the province, for southwestern B.C. and for Clayoquot Sound.
Most of the statistics reported here are summarized from the forest cover database for forest land in TSAs, collected and maintained by the Ministry of Forests’ Forest Inventory Branch. This database, initially developed for measuring available timber volumes, contains information on:
The database has two major limitations. Since it was originally developed as a timber inventory, it contains little data about other resources (e.g., wildlife habitat or wetland type), nor does it cover the province in a uniform fashion. Inventory information is not readily available for approximately 18% of B.C., including:
Maps for most TFLs were obtained directly from the licensees. Inventory data for TFLs in the Nelson Forest Region are from maps assembled for the Commission on Resources and Environment.
Maps for the larger, older provincial and national parks[26] were derived from the 1956-58 Continuous Forest Inventory. Inventory information from these maps is considered to be of lower reliability than that from TSA or TFL maps.
To support integrated resource management, a far greater range of information on forests is needed. The multi-agency Resource Inventory Committee is in the process of specifying the type and form of information required for an inventory containing a wide range of environmental and cultural information. This new, multiresource inventory will be suitable for land use planning at a variety of scales. The new provincial inventory is scheduled to be implemented by April 1995.
The issue of net land base (land available and suitable for growing timber) is not dealt with in this report. Net land bases for individual management units (TSAs and TFLs) are currently being redetermined through the Timber Supply Review process (see Section 3.6). New net land bases for each unit, and for the province, will be available by December 1995. Government’s decisions in response to recommendations from the Protected Areas Strategy (PAS) and Commission on Resources and Environment (CORE) will continue to alter net land bases for individual management units for the foreseeable future.
This section reports current inventory statistics for productive forest land in TSAs and TFLs. Information is provided by forest area and timber volume for stands, classified by site class, maturity and leading species.
– stands with lodgepole pine, whitebark pine or deciduous species as leading species, of stand age
80 years or less
– stands with conifers other than lodgepole or whitebark pine as leading species, of stand age 120
years or less.
Mature forests are defined as:
– stands with lodgepole pine, whitebark pine or deciduous species as leading species, of stand age
greater than 80 years
– stands with conifers other than lodgepole or whitebark pine as leading species, of stand age greater
than 120 years.
Leading Species: Leading species are the dominant tree species for the individual stands on forest cover maps. Tree species groupings are defined in Section 3.2.1.
Figure 3.3 shows, for productive forest land in all TSAs, the area in good, medium, poor and low site classes, the areal proportion of each site class that is mature/immature timber, and the areal proportion of all productive forest land in TSAs that is mature/immature timber. The predominant site class by area is “poor” (48% of total area); 64% of the productive forest area (all site classes) is covered by mature timber. Much of the low site class area is excluded from the productive forest land base.
Figure 3.4 shows, for productive forest land in all TSAs, the timber volume in good, medium, poor and low site classes, the volume proportion of each site class that is mature timber, and the volume proportion for all site classes that is mature timber. The predominant site class by volume is “medium” (46% of total volume); poor site classes make up only 37% of the volume (though they cover 48% of the area [Figure 3.3]). Approximately 84% of productive forest volume in all site classes is in mature timber.
Figure 3.5 shows, for productive forest land in all TFLs, the area in good, medium, poor and low site classes, the areal proportion of each site class that is mature/immature timber, and the areal proportion of all productive forest land in TFLs that is mature/immature timber. The predominant site class by area is “medium” (42% of total area), compared to the predominant “poor” site class in TSAs (Figure 3.3). The majority (59%) of productive forest area (all site classes) is covered by mature timber — slightly less than for TSAs. Volume figures by site class and maturity for TFLs are not available for this report. (Methods used for estimating site class in TFLs differ from those used in TSAs.)
Figure 3.6 shows, for productive land in all TSAs, the area by leading species in good, medium, poor and low site classes. The predominant species are pines and spruces, which together make up 57% of the area in TSAs.
Figure 3.7 shows, for productive land in all TSAs, the volume by leading species in good, medium, poor and low site classes. The predominant species are pines (primarily lodgepole pine) with 24% of the timber volume, spruces (primarily white spruce and its hybrids) with 22% and true firs (Abies spp.) comprising 14% of the timber volume. (True firs [Abies spp.] have been referred to as “balsam” in previous reports; Douglas-fir [Pseudotsuga menziesii] has been referred to as “fir” in previous reports.)
Figure 3.8 shows, for productive land in all TSAs, the timber area by leading species in mature and immature age classes. Species characteristic of the wet west coast and the interior wet belt, such as cedars (western redcedar and yellow-cedar) and hemlocks (western hemlock and mountain hemlock), are predominantly mature. This is due to the scarcity of fire in these areas. Conversely, species more characteristic of B.C.’s interior, such as spruces and pines, display more balance between mature and immature forests due primarily to the prevalence of stand-destroying fire.
Over the last decade, TSAs decreased in size by 1.3 million hectares and TFLs increased in area by 625 000 hectares. Over the same period, methods used for computing volume figures changed several times. These changes tend to obscure other changes in areas and volumes resulting from forestry activities. Some figures are unavailable for TFLs.
Figures 3.9, 3.10 and 3.11 show changes in the area of immature and mature forest, by site class, for all TSAs and TFLs between 1984 and 1994.
Figure 3.9 shows changes in area for TSAs. Most of these changes result from the transfer of approximately 1.3 million hectares to various land designations, including TFLs (about 625 000 hectares), protected areas, agricultural and residential uses or rights-of-way. Most (about 94%) of the area lost was covered with immature timber. Overall, from 1984 to 1994 TSAs gained about 700 000 hectares of “good” sites, lost about 1.5 million hectares of “medium” sites, lost about 1.3 million hectares of “poor” sites and gained about 800 000 hectares of “low” sites.
Figure 3.10 shows the changes in area for TFLs from 1984-1994. Most of these changes are due to the 625 000 hectares transferred to TFLs from TSAs during this period. Most (about 83%) of the area gained was covered with immature timber. Overall, from 1984 to 1994, TFLs gained almost 685 000 hectares of “good” sites and about 66 000 hectares of “medium” sites and lost about 10 000 hectares of “poor” sites and 50 000 hectares of “low” sites.
Figure 3.11 shows 1984-1994 changes in area for TSAs and TFLs combined. There were approximately 700 000 hectares less in TSAs and TFLs in 1994 than in 1984. These areas were transferred to other land designations. Almost all (99%) of the area lost was covered with immature timber. Overall, TSAs and TFLs gained about 900 000 hectares of “good” sites, lost about 1.7 million hectares of “medium” sites, lost about 1.5 million hectares of “poor” sites and gained approximately 800 000 hectares of “low” sites.
Figure 3.12 shows changes in volume of mature and immature forest, by site class, for TSAs only (comparable information is unavailable for TFLs). The most obvious change is due to changes in land allocation. There were approximately 604 000 000 cubic metres less in TSAs in 1994 than in 1984. Volume lost was fairly evenly split between immature timber (about 44%) and mature timber (56%), even though 94% of the area lost was immature timber (Figure 3.9). Overall, TSAs gained approximately 65 000 000 cubic metres of timber on “good” sites, lost about 190 000 000 cubic metres of timber on “medium” sites, lost about 441 000 000 cubic metres of timber on “poor” sites and lost about 38 000 000 cubic metres of timber on “low” sites.
Figure 3.13 shows changes in area by leading species for TSAs between 1984 and 1994. Of the 1.3 million hectares lost from TSAs between 1984 and 1994, 57% of the area was pines (mainly lodgepole), 21% was spruces and 10% was deciduous species. Two stand types increased in area over that time: hemlocks (approximately 225 000 hectares) and true firs (about 162 000 hectares). (True firs [Abies spp.] have been referred to as “balsam” in previous reports; Douglas-fir [Pseudotsuga menziesii] has been referred to as “fir” in previous reports.)
Figures 3.14, 3.15 and 3.16 show changes in volume by leading species for TSAs, TFLs, and TSAs and TFLs combined, 1984-1994.
Figure 3.14 shows changes in timber volumes by leading species for TSAs, 1984-1994. These changes arise from land transferred out of TSAs and volumes reduced through harvesting. Overall for TSAs, timber volumes dropped by slightly over 600 000 000 cubic metres (7.8%) over that period. All forest types except hemlocks (which gained 124 000 000 cubic metres) lost volume between 1984 and 1994. Largest losses were in spruces (15.4% of total volume lost), lodgepole pine (10.3% of total volume lost) and true firs (14.3% of total volume lost).
Figure 3.15 shows changes in mature timber volumes by leading species for TFLs, 1984-1994. Overall for TFLs, timber volumes dropped by 8 092 000 cubic metres (0.6%) over that time period. This loss is mainly in true firs (25.1% of total volume lost) and western redcedar (8.4% of total volume lost). Major stand types increasing in volume over that time were spruces (gained 48 606 000 cubic metres) and lodgepole pine (gained over 35 000 000 cubic metres). Losses are greatest for TFLs in coastal species (western redcedar and hemlocks) because TFLs are concentrated largely on the coast; losses are greatest for TSAs in interior species (spruces and lodgepole pine).
Figure 3.16 shows 1984-1994 changes in timber volumes by leading species for TSAs and TFLs combined. Major volume losses occur in spruces (243 000 000 cubic metres lost) and true firs (225 777 000 cubic metres lost). All species showed volume losses except hemlocks, which gained 128 000 000 cubic metres.
Figures 3.17 and 3.18 show changes in area and volume by age class for TSAs, 1984-1994.
Figure 3.17 shows changes in TSA areas by age classes, 1984-1994. Losses are due to logging (returning stands to younger age classes) and to land reassigned to land administration classes other than TSAs. Most of the area lost was from lodgepole pine stands in the 41-60 and 81-100 year age classes. Most of the area gained is in the 1-20 year age class (due to logging and natural disturbances such as fire in older age classes) and in the age classes 101-120, 121-140 and 141-250, due to younger stands entering those age classes.
Figure 3.18 shows changes in volume for all TSAs by age classes, 1984-1994. Major volume losses occurred in the 81-100 year (364 000 000 cubic metres, much of it lodgepole pine) and 141-250 year (338 000 000 cubic metres, mainly spruce and true firs) age classes. Volume increases occurred in the 250+ year (180 000 000 cubic metres, mostly hemlock) and 121-140 year (mostly lodgepole pine) age classes. As has been noted earlier, overall TSAs lost 663 365 000 cubic metres of timber volume between 1984 and 1994.
