Summary
Published in Forest Ecosystems 5(1): 30 https://doi.org/10.1186/s40663-018-0148-9
Background: In the context of ecosystem management, the present study aims to compare the natural and the present-day forested landscapes of a large territory in Quebec (Canada). Using contemporary and long-term fire cycles, each natural forest landscape is defined according to the variability of its structure and composition, and compared to the present-day landscape. This analysis was conducted to address the question of whether human activities have moved these ecosystems outside the range of natural landscape variability.
Methods: The study encompassed a forested area of 175 000 km2 divided into 14 landscapes. Using a framework that integrates fire cycles, age structure and forest dynamics, we characterized the forest composition and age structures that resulted from three historical fire cycles (110, 140, and 180 years) representative of the boreal forest of eastern Canada. The modeled natural landscapes were compared with present-day landscapes in regard to the proportion of old-growth forests (landscape level) and the proportion of late-successional forest stands (landscape level and potential vegetation type).
Results: Four landscapes (39%) remain within their natural range of variability. In contrast, nine landscapes (54%) show a large gap between natural and present-day landscapes. These nine are located in the southern portion of the study area, and are mainly associated with Abies-Betula vegetation where human activities have contributed to a strong increase in the proportion of Populus tremuloides stands (early-successional stages) and a decrease of oldgrowth forest stands (more than 100 years old). A single landscape (7%), substantially changed from its potential natural state, is a candidate for adaptive-based management.
Conclusion: Comparison of corresponding natural (reference conditions) and present-day landscapes showed that ten landscapes reflecting an important shift in forest composition and age structure could be considered beyond the range of their natural variability. The description of a landscape’s natural variability at the scale of several millennia can be considered a moving benchmark that can be re-evaluated in the context of climate change. Focusing on regional landscape characteristics and long-term natural variability of vegetation and forest age structure represents a step forward in methodology for defining reference conditions and following shifts in landscape over time.
Sector(s):
Forests
Categorie(s):
Scientific Article
Theme(s):
Forest Ecology, Forestry Research, Forests
Departmental author(s):
Author(s)
GRONDIN, Pierre, Sylvie GAUTHIER, Véronique POIRIER, Patrice TARDIF, Yan BOUCHER and Yves BERGERON
Year of publication :
2018
Format :
Paper
How to get the publication :
ISSN
2197-5620
Keywords :
aménagement écosystémique, états de reference, variabilité naturelle, résilience, cycle de feu, structure d’âge, dynamique forestière, vegetation potentielle, écologie du paysages, paysage naturel estimé, paysage contemporain, écologie forestière, article scientifique de recherche forestière, forest ecology, ecosystem management, reference conditions, natural variability, resilience, fire cycle, age structure, forest dynamics, potential vegetation type, landscape ecology, theoretical natural landscape, present-day landscape
