0339-B4
Christian Messier, Brigitte Bigué and Louis Bernier 1
Canada has a huge forest resource and yet, in many parts of the country, some wood shortages are occurring or predicted within the next 25 years. The situation is critical since there is growing pressure from society to increase protected areas, modify our forestry practices to protect biodiversity values, and maintain more old-growth forests within our managed forests. This paper reviews the evolution of the dominant paradigm in forestry, discusses the basic principles of the concept of sustainable forest management from an ecological standpoint, and then proposes to adopt some kind of zoning principle (TRIAD or QUAD) to help achieve society's goal of sustainable forest management of the Canadian forest. An example is provided for the boreal forest of Canada that shows that it is possible to put as much as 12% of the productive forest aside as protected areas and implement ecosystem management on the majority of the landbase if some kind of intensive and super-intensive forestry practices are implemented on 14% of the landbase. Four categories of silvicultural treatments/systems are proposed to provide managers with a range of stand management options that would likely be acceptable in various landuse zones: 1) Systems emulating natural processes; 2) Semi-natural systems; 3) Traditional intensive systems; and 4) Super-intensive systems. Some examples are also provided that show how intensive and super-intensive forestry can be used to help protect the environment. To develop these new ideas further and to test them on a scientifically rigorous footing, a new research network LIGNICULTURE-QUEBEC was recently established in eastern Canada. The day may have come when fast-growing plantations will be associated with forest ecosystem protection and not the reverse.
The economic importance of the Canadian forest sector is obvious, with nearly $40billions in exports for 1999 (CCFM 2002). Some 200 million m3 of wood are harvested every year in Canada generating numerous economic spin-offs in the various regions of Canada, including almost 300,000 direct jobs, even without counting recreational and tourism activities. Unfortunately, in many parts of Canada, the allowable cut has already been reached and serious shortages are predicted within 25 years, despite the annual reforestation operations carried out in all provinces The situation is particularly critical since the anticipated wood shortage is exacerbated by growing pressures from society to (1) set aside a large proportion of the forest area for purposes other than logging (2) to change current forestry practices in order to maintain a larger quantity of standing trees, snags and deadwood following cutting (often called new forestry, ecological forestry or ecosystem forest management) and (3)to maintain a certain proportion of old-growth forest within managed forest areas. As well, the prospect of an increasing frequency of fire and insect outbreaks in the future associated with climate change could further reduce the quantity of fibre available for harvesting.
To deal with these new challenges, a new approach is gaining popularity in Canada under which the forest area could be divided into four management areas, ranging from (1) full protection areas, in which logging is banned, (2) low intensity management areas, where some harvesting is allowed but following the principle of ecosystem forest management, (3) intensive management areas, where traditional intensive forestry interventions are used to increase forest productivity to (4) super-intensive forestry areas (ligniculture), where priority is given to fibre production through short-rotation plantations. If well planned, intensive and super-intensive forestry may also be used as a tool for promoting the protection and conservation of the forest resource.
The ultimate accomplishment is obviously sustainable management of the forest. What does sustainable development mean? According to the Brundtland Report (1987), it means development that meets the needs of present generations, without compromising the ability of future generations to meet their own needs. In forestry, we tend to talk about an approach for using the forest ecosystem that maintains both the integrity and health of forest ecosystems while maintaining their socio-economic contributions (CCFM 1997). Indeed, to be sustainable, it is essential that forest management be ecologically viable, economically feasible and socially desirable.
The TRIAD (Hunter 1990) principle is an interesting concept that can help in promoting sustainable management. This principle incorporates the first two conservation concepts discussed above, namely ecosystem management and full protection, while pursuing the objective of production. More concretely, this principle is based on a scenario whereby the forest area is divided into different management areas, each having a different set of goals and objectives. To better illustrate the concept, we provide an example on how the forest of Canada could be divided where the ecosystem management approach could be applied on 74% of the forest area, while 12% would receive full protection and the last 14% would be devoted to intensive management. Of this 14%, Messier and Kneeshaw (1999) advocated to divide it into intensive management, using traditional silvicultural techniques, and super-intensive management, using more productive exotic and hybrid species (QUAD) (Figure 1).
Figure 1 An example of how one could divide the productive forest of Canada into 4 different zones (QUAD) to allow for the achievement of sustainable forest management
Many regions of Canada are in the process of adopting some form of the "TRIAD" approach to forest management (Harris 1984, Rowe 1992, Hunter and Calhoun 1996) or "QUAD" approach (Messier and Kneeshaw 1999). While the TRIAD/QUAND concept has been well developed for landscape goals, at this time there have not been good descriptions of the stand level treatments suitable for each of the above categories. Indeed, with good planning and integration of stand level treatments, managers may be able to develop forests that serve a wide variety of goals.
Four categories of silvicultural treatments/systems are proposed here to provide managers with a range of stand management options that would likely be acceptable in various landuse zones: 1) Systems emulating natural processes; 2) Semi-natural systems; 3) Traditional intensive systems; and 4) Super-intensive systems. These systems cover the extremes from ecosystem restoration to intensive plantation systems. This is an arbitrary division into only 4 categories, as in reality the categories listed fit on a gradient from no intervention to extreme intervention. While we may wish to create various landscape zones to meet timber, social and biodiversity objectives, managers should be given some flexibility to create the range of stand types using different silvicultural procedures. For example, while purists may disagree, it might be desirable both economically and environmentally to maintain the use of intensive management procedures listed in Figure 1 to create specialized habitats within the ecosystem management landscape zone.
DOMTAR, a large paper making forest company in eastern North America, has embarked upon a large-scale poplar farm program, designed to provide around 10 % of its fibre needs when first harvest commences in the early 2010's. When fully implemented, there will be approximately 15,000 ha of private land under cultivation, with an approximate 15 year rotation. Realized growth rates will ultimately determine the exact cut rotation volume and total hectares required to meet this goal.
This poplar program is based on research which began in 1998 when the first collections of hybrids developed by the Quebec government researchers were put into a trial at DOMTAR site. Thirty different kinds of clones are used. Several hundred hectares of hybrid poplar plantations are put into the ground every year .
The primary selection traits used by the researchers in these programs include adaptability, resistance to pests, growth, form and wood quality. Combined with the tree improvement is a dedicated silviculture program. This program covers research on site preparation, mounding, composition and rate of fertilizer applications, biosolid utilization and nursery stock.
The aim of this research program is to provide mills with an alternative fiber supply of the best genetic material grown on an economical short rotation. Where required, DOMTAR also supports research that is relevant to reducing risk to crop failure (i.e: insects and disease, pollen flow etc.).
Intensive management makes it possible to achieve productivity gains over wild or extensively managed stands by harvesting at a relatively young age, just after the culmination of mean annual increment. Careful establishment and density control of conifer plantations in Ontario and Quebec (J. Beaulieu, pers. comm.) have yielded nearly 300m3/ha by year 40. In Canada, hybrid poplar plantations have been the focus of intensive plantation operations. They may yield up to 37 m3/ha/yr per year in Coastal British Columbia but the yields are likely to be much less than this in sites with colder winters and seasons of water stress (Table 1). While there are relatively large plantations by Domtar in Ontario, Pacifica Paper and Scott Paper in southern British Columbia and plans to scale up plantations by Al-Pac in Alberta, the current area in hybrid poplar plantations is ~7000 ha, nationwide (Van Oosten 2000). Larch plantations in Quebec have produced 5 to 8 tonnes/ha in 5 to 10 years or sawlog timber in 20 to 25 years.
Table 1 Current and anticipated hybrid poplar growth rates* (m3/ha/yr) for various regions of Canada - (Best and Average)
Region or Province |
Current growth rate m3/ha/yr |
Anticipated future growth rate (m3/ha/yr) | ||
Best |
Average |
Best |
Average | |
Southern Quebec |
19 |
9 |
20 |
14 |
Quebec - Boreal Region |
- |
- |
12 |
10 |
Southeast Ontario |
15 |
> 12 |
18 |
14 |
Prairie Region & NE BC |
N/A |
12 |
19 |
16 |
BC Northern Interior |
- |
- |
20 |
17 |
BC Southern Interior |
30 |
- |
35 |
25 |
BC Coast |
37 |
23 |
45 |
35 |
Source: Van Oosten 2000 | ||||
Increased levels of management intensity, however, can also play an integral part in maintaining wood supply in forested landscapes managed to maintain biological diversity (Binkley 1997). In the calculations presented in Table 2, we demonstrate that with intensive management on a relatively small area, the same level of wood production can be maintained, even if 15% of the area is set aside as reserves and a large part of the area (70%) is managed semi-naturally. Using data from the state of Canada's forests in 1998/1999, we have estimated that the annual productivity of the boreal forest (annual allowable cut) is about
141 x 106 m3/yr, with an actual cut of 108 x 106 m3/yr. The value of 154 x 106 m3/yr of wood available for harvest developed in the calculations of Table 2 is therefore well above the natural productivity despite the inclusion of reserves and the low productivity from a large part of the landscape.
Table 2 Area of boreal forest lands (ha x1000) in Canada, in different site classes (site index (SI) at age 50). The land was broken down into three categories of management: 15 % in protected areas; 70% under semi-natural management; 10% in plantations and 3% in super-intensive systems and different levels of productivity were assumed for each area. There was a bias to include more of the highly productive lands in the more intensive systems. Note that there was no super-intensive management applied to the SI <10 m productivity class.
MANAGEMENT |
SI < 10 m |
SI 10 to 15 m |
SI 15 to 20 m |
SI > 20 m |
|
TOTAL AREA (1000 ha) |
60 644 |
47 972 |
30 976 |
945 |
140 537 |
1) Protected area (15%) (1000 ha) |
9 096.6 |
7 195.8 |
4 646.4 |
141.8 |
21 080.6 |
2) Semi-natural(70%) (1000 ha) |
44 450.8 |
33 580.4 |
20 683.2 |
303.2 |
98 375.9 |
Productivity (m3/ha/yr) |
0.7 |
1 |
1.2 |
1.5 |
|
Production (1000 m3) |
29 715.6 |
33 580.4 |
26 019.8 |
454.8 |
89 315.8 |
3) Plantations(10%) (1000 ha) |
4 064 |
4 797 |
2 097 |
200 |
10 961 |
Productivity (m3/ha/yr) |
1.5 |
3 |
3.5 |
5.0 |
|
Production (1000 m3) |
6 096 |
14 391 |
7 339.5 |
1 000 |
27 826.5 |
4) Super Intensive (3%) (1000 ha) |
Nil |
916.1 |
3 000 |
300 |
4 216.1 |
Productivity (m3/ha/yr) |
Nil |
6 |
9 |
15.0 |
|
Production (1000 m3) |
Nil |
5 496.6 |
27 000 |
4 500 |
36 996.6 |
Total production |
154 138.9 m3 | ||||
Note: The productive boreal forest of Canada (140.5 x 106 ha, Lowe et al. 1996) was divided into the four SI classes: (http://www.pfc.forestry.ca/monitoring/inventory/canfi/canfie.html). The estimate of the area of each SI class was taken from the site index from different permanent sample plots (PSP) in Canada and is based upon the dominant species in each PSP. In these calculations we amalgamated the Emulating Natural Processes systems into the Semi-natural Management category. There is likely to be only slightly different levels of productivity between these management systems; perhaps there will be a slightly longer regeneration lag in the Emulating Natural Processes system. To account for this regeneration lag, we intentionally assigned a low estimation of productivity to these systems. The productivity estimates were scaled up for the Plantation and Super-intensive systems based upon the overall values in the literature.
When selecting sites for intensive production, the need to protect and to apply ecosystem forestry on the productive sites must also be taken into account. It is important not to monopolize all the productive sites for intensive management, because there would be a high risk of destroying habitats that are important for maintaining biodiversity. It is therefore realistic to consider that approximately 45% of our current wood needs can be met from only 15% of the area through intensive forestry. This way, the ecosystem management approach could then be applied to another 70% of the productive area in order to obtain the remaining 55% of our wood requirements. This would make it possible to set aside a large proportion of the forest land for full protection.
Furthermore, such intensive tree-growing projects may even be environmentally beneficial. For example, researchers have proposed a project using fast-growing poplars along rivers in agricultural areas. It is plausible that the trees would intercept the excess nitrate and phosphorus, which are major pollutants from farmland. Fast-growing species such as hybrid poplar and larch are being considered for large areas of abandoned farm land with slower-growing highly valuable hardwood species (maple, walnut, ash, oak, etc.) or spruce in the understory to rehabilitate these once forested areas. As well, consideration is being given to using new mixed plantations to create "green" corridors that would connect the various isolated pockets of forests scattered across the most inhabited parts of Canada.
In the fall of 2001, a group of researchers from several universities and government research centres, as well as the forest industry, created a new research network: Ligniculture-Québec. The mission of this organization is to coordinate and promote Quebec's efforts in the field of fast-growing plantation research, development and technology transfer. The project has five main research components:
It is necessary to ensure that the genetic selection of superior and/or improved varieties will promote maximum fibre production, in terms of both quantity and quality. This genetic selection must take into account the medium- and long-term ability of the stands to adapt to predicted climatic changes and to survive climatic stresses and insect and disease epidemics. To this end, new selection methods combining the evaluation of early physiological characteristics and genetic markers indicative of commercial and adaptive characteristics will be proposed.
Plantation growth and yield will be studied with reference to the species, sites, need to control competition and optimal spacing of the trees as a function of the architectural characteristics of the species and hybrids used. In order to conduct virtual tests and experiments on the effects of various factors on plantation growth and productivity (climatic changes, windfall risks, effects of spacing and pruning on long-term productivity), we will develop and adapt existing simulation models at the tree level which incorporate the main physiological processes and 3D simulation of tree structure, as well as models at the stand level. Once tested and validated, these models will be used to optimize future plantation sites, to ensure early selection of desirable characteristics, and to chose the optimal spacing between trees for maximum wood production and quality.
The protection of future plantations against pathogens and insect pests will also receive special attention. The selection of more resistant lines, analysis of the factors that reduce the susceptibility of the plantations to infestations, and the development of biological control methods are viable solutions that will be studied and proposed. To this end, consideration will be given to approaches based on the development of molecular and conventional early detection methods and the development of new biotests.
The rapid growth of plantations can cause nutrient deficiencies as well as health problems in the medium and long term. It is therefore preferable to evaluate the nutritional requirements of the various hybrids and clones that will be used based on the sites selected. Nutrient amendments must therefore be considered. In addition, the possibility of using sewage sludge and various processing residues as fertilizer will be studied.
Forest landscape analysis models will be developed (SELES/LANDIS and LANDSCOPE) to enable us to better evaluate how these intensive fibre production areas will be situated in time and space within a given area. These analysis models will make it possible to minimize the impact on wildlife and plant habitats and thus preserve the biodiversity of the area. As well, socio-economic analyses will be conducted to determine the best strategies for establishing these fast-growing plantations.
In order to maximize fibre production, priority will be given to two groups of high-yielding species, hybrid larches and poplars. As well, the possibility of incorporating species of high commercial value such as white pine, Norway spruce, white spruce and highly valuable hardwood species (sugar maple, ash, oak, walnut and yellow birch) in the understory will be studied. Three pilot regions currently logged on an industrial basis will be targeted, namely southern Quebec, central Quebec and Abitibi. It is expected that Ligniculture-Québec will eventually take the form of a university-government-industry research and development cooperative, similar to those that already exist in the United States.
As we have shown, it appears possible, even desirable, to use increased yield, fast-growing plantations in Canada as a means of achieving fibre production while promoting the protection and conservation of our forest heritage. To this end, we must be innovative and, especially, address the issue of forest management at a regional level (i.e. landscape level). The implementation of fast-growing plantation on a small portion of our productive forest land could become part of the Canadian strategy to achieve the sustainable management of its forest and certification from such international organisations as FSC (Forest Steward Council). In the future, the establishment of fast-growing plantations and/or the introduction of fast growing exotics or hybrids on a portion of the landscape may well be associated with forest ecosystem protection and not the reverse.
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Van Oosten, C. 2000. Activities related to poplar and willow cultivation and utilization in Canada 1996 - 1999. Report to the 21st Session of the International Poplar Commission Portland, Oregon, USA. September 24 - 28, 2000. SilviConsult Woody Crops Technology Inc. March, 2000
1 Scientific co-director of the LIGNICULTURE-QUÉBEC network, Dept. of Biological Sciences, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, Montréal (Québec), Canada. [email protected];
Website: http://www.unites.uqam.ca/gref