资源环境科技发展态势分析平台

Globally, there is an increasing demand for wood products. Because of their productivity, forest plantations will increasingly serve to meet this demand. A cumulative anthropogenic disturbance, such as a plantation scenario, could alter resilience of natural forests, thereby triggering alternative successional pathways towards a state that is predominated by planted species. These alternative ecosystems could represent a threat to biodiversity and ecosystem services that are provided by natural forests. Our objective in this study was to evaluate whether a spruce plantation scenario alters the resilience of natural balsam fir stands in the balsam fir ecological region of Quebec (Canada). We studied successional pathways in 897 spruce plantations covering a 40-year period. The spruce plantation scenario does not seem to have altered resilience of natural balsam fir stands. The main tree species naturally regenerating on balsam fir ecological site types had indeed recovered from the plantation scenario to the detriment of planted spruce species. Balsam fir stands are resilient to the spruce plantation scenario, largely because of the effective regeneration processes of balsam fir and birch species, compared to spruce species. Maintaining functional regeneration processes is a way to maintain resilience and insure that biodiversity and ecosystem services will be gradually restored after anthropogenic disturbances. Regeneration processes should enable a resilient forest to follow natural successional pathways back to its pre-disturbance composition, structure and functions. Hence, planting a tree species in a resilient forest that is not in accordance with the successional pathway of the natural forest could put silvicultural investments at risk. With increasing use of plantations to meet wood demand, some sites inevitably will undergo consecutive cycles of the plantation scenario. Cumulative effects of consecutive plantation scenarios may then be detrimental to the resilience of balsam fir stands. We propose initiatives to mitigate these potential threats.