Forest Management and Climate Change in the Walloon Region of Belgium C
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64 65 Forest management and climate change in the Walloon Region of Belgium C. Laurent Management measures promoted n Belgium, forestry policy and ad- • use of tree species and provenances by the government of Wallonia ministrative functions are mostly de- best adapted to current site condi- are intended to help increase centralized, and forest management tions so that they can tolerate both the resilience of forests to Iauthority rests with the governments of abiotic and biotic changes in the environmental changes, while the countryʼs three regions, Flanders, environment. boosting the contribution of forests Wallonia and Brussels. Wallonia, in The second is the use of appropriate to climate change mitigation. the southern part of the country, is a silvicultural techniques to anticipate the small, densely populated region, and particular risks to forests from climate forest accounts for about one-third of change, especially the expected in- its 16 844 km2 area. Measures developed creased frequency of storms, increased in Wallonia to achieve a multifunctional prevalence of pests, stress from extreme forest management approach suited to climatic episodes with alternating periods a densely populated region encompass of drought and excessive rainfall and the measures for adapting to future climate predicted global rise in temperatures. Soil change. These measures follow two com- and water conservation measures improve plementary thrusts. the way forest ecosystems regulate hy- The first is the maintenance, or prefer- drological cycles. Lower stand densities, ably the improvement, of the capacity earlier thinnings and multistorey forest of forest ecosystems to adapt to envi- systems enhance the ecosystemʼs resist- ronmental change through: ance to climate stress and pests.The • development of broader biological choice of well adapted species and prov- diversity within stands, based on enances also contributes to carbon storage diversification of primary and com- by increasing biomass increments in the panion species, but also on genetic forests and by favouring timber products diversification (through the use of suitable for longer-term use. more different provenances and seed This article describes such measures for stands) and appropriate silvicultural increasing the ability of forests to adapt techniques; to climate change and shows how they Multistorey stands Christian Laurent is forest engineer in the enhance the ecosystem’s Forest Resources Service, Ministry of the resistance to climate Walloon Region, Directorate-General for Natural stress, and in Belgium Resources and Environment, Nature and Forest they are encouraged Division, Belgium. whenever possible O. HUART O. Unasylva 214/215, Vol. 54, 2003 Unasylva 214/215, Vol. 54, 2003 64 65 converge with the ecological, economic tems: diversification and the adaptation stands of a broader range of species and social objectives of multifunctional of species to local conditions. for use in both tree improvement pro- forest management. grammes and conservation; Diversification. Diversification means • the Comptoir des matériels forestiers MULTIFUNCTIONAL FOREST ensuring a wide diversity in the forests de reproduction, a forest tree seed MANAGEMENT IN WALLONIA at all levels. In terms of genetics, di- centre which manages seed stands The population density in Wallonia is versity is sought through the use of a and the harvesting, processing and 199 persons per square kilometre, with mosaic of productive and well-adapted distribution of reproductive materi- 544 800 ha or 0.16 ha of forest land per provenances, whether these be of indig- als to the public and private sectors. person (Lecomte et al., 2003). Given enous species or introduced ones such Diversification is encouraged through the general context of intense pressure as Douglas fir (Pseudotsuga menziesii) subsidies for regeneration in which tree on land, multifunctional management or larches (Larix spp.). Monoclonal or species mixtures are used. Finally, the is possible only through a system of oligoclonal plantations (i.e. plantations inclusion of 150 000 ha of forest within multifunctional forest zones, in which with less than 20 to 30 clones) are pro- the network Natura 2000 (a European each unit has a primary objective but scribed. In terms of species, mixtures network for the conservation of natural is managed in such a way as best to of the dominating tree species are habitats and wild fauna and flora) will guarantee the productive, ecological favoured, and understorey species are provide a major boost to diversification and social functions of the forest. to be maintained or even introduced efforts. In the case of the 48 percent of forests in plantations or natural regeneration. Apart from its effects on biodiversity that are publicly owned, their primary Ecosystem diversity is ensured by pro- and on adaptation of forests to climate functions are defined in their manage- tecting natural ecosystems or those only change, diversification of species may ment plans. Even when soil, water or slightly modified by humans, as well as also have positive economic effects, biodiversity conservation is identified secondary forests with high biological potentially offering a greater capacity as the primary objective of management, diversity. to cope with market fluctuations and the economic and social functions of the In Wallonia, implementation of di- opening access to specialized niches for forest are also covered, although they are versification measures is supported quality wood and non-wood products. It accompanied by restrictions to guarantee particularly by the efforts of two in- also enhances the landscape and tourism the fulfilment of the primary objectives. stitutions: roles of forests. Similarly, general measures are adopted • the Centre de recherche sur la nature, in production zones with a view to en- la forêt et le bois, a research centre that Use of species adapted to the site. It is suring that the ecological functions of develops ecosystem conservation recommended to regenerate or introduce the forest are maintained. Production methods for field implementation those species and provenances that are is focused on quality products that are and identifies provenances and seed best adapted to the current conditions suitable for high added value and not on mass production. In the case of privately owned forests, incentives and sensitization measures are applied, with a view to ensuring a balance among the various functions of the forests. BELGIQUE DE FORESTIÈRE ROYALE SOCIÉTÉ Diversification of species is a means MANAGEMENT MEASURES of improving the FOR ADAPTATION TO CLIMATE adaptive capacity of CHANGE forest ecosystems; mixtures of the Improvement in the adaptive dominating tree capacities of forest ecosystems species are favoured, Two routes are essential for improving and understorey species are the adaptive capacity of forest ecosys- maintained Unasylva 214/215, Vol. 54, 2003 Unasylva 214/215, Vol. 54, 2003 66 67 An example of “dynamic silviculture”: Douglas fir with wide spacing and early first thinning and pruning • improved biodiversity and soil conservation as a result of more abundant understorey vegetation; • more regular and gradual recycling of mineral elements, improving eco- system functioning and preventing the leaching of nutrients during harvesting. The use of “dynamic silviculture” C. LAURENT C. to maintain an open-stand structure of the site and climate, as these have better quality of product. It also pre- is encouraged through subsidies for a greater tolerance to both abiotic and vents adverse effects of species on the regeneration which impose a certain biotic fluctuations in their environment. environment, an essential consideration planting density range, subsidies for Certain tree species and species mix- for soil and water conservation. early thinning and extension resources tures are also favoured for their rooting such as guides to good practices. For characteristics to address the specific Silvicultural techniques public forests, circulars are disseminated problems of windthrow and drought. A variety of silvicultural techniques addressing silvicultural standards. The use of well-adapted species is widely promoted by the Walloon Region In terms of social and economic ben- also encouraged through information will reduce the dangers to forests from efits, this type of silviculture, augmented and incentives. future climate change. by pruning (which is also encouraged • Guidelines drawn up for the Wal- by subsidies), increases the profitabil- loon Region by an inter-university “Dynamic silviculture”. The treat- ity of forest management by allowing team (Weissen et al., 1991; Weissen, ment termed “dynamic silviculture” in a reduction in rotation times and faster Bronchart and Piret, 1994) provide Belgium (André et al., 1994) involves production of timber of dimensions suit- clear descriptions of the ecological the maintenance of relatively low densi- able for higher added-value processing. requirements of the 14 conifer spe- ties (number of stems and basal area per Maintaining fewer standing trees and cies and 30 deciduous species most hectare) through the establishment of less growing stock also reduces finan- widely used, including companion wider spacing between stems or through cial risks as less capital is exposed to species, together with keys for rigorous early thinning of regenerated potential biotic or abiotic disaster. An choosing species according to the patches. The objectives with