Have some landscapes in the eastern Canadian boreal forest moved beyond their natural range of variability?

作     者：Pierre Grondin Sylvie Gauthier Veronique Poirier Patrice Tardif Yan Boucher Yves Bergeron 

作者机构：Direction de la Recherche ForestiereMinistere des Foretsde la Faune et des Pares (MFFP)2700rue EinsteinQuebecQC GIP 3W8Canada Ressources Naturelles Canada/Natural Resources CanadaService Canadien des forets/Canadian Forest ServiceCentre de foresterie des Laurentides/Laurentian Forestry Center1055 rue du P.E.P.SQuebecQC G1V 4C7 Canada Institut de Recherche sur les ForetsUniversite du Quebec en Abitibi-Temiscamingue445boul.de I'UniversiteRouyn-NorandaQC J9X 5E4Canada Centre d'etude de la ForetUniversite du QuebecMontreal CP 8888succ AMontrealQC H3C 3P8Canada 

出 版 物：《Forest Ecosystems》 (森林生态系统（英文版）)

年 卷 期：2018年第5卷第4期

页      面：412-428页

核心收录：

学科分类：0710[理学-生物学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 0907[农学-林学] 0829[工学-林业工程] 09[农学] 0901[农学-作物学] 0833[工学-城乡规划学] 0713[理学-生态学] 0834[工学-风景园林学（可授工学、农学学位）] 

基　　金：funded by the Ministère des Forêts de la Faune et des Parcs du Québec(MFFP).The funds were used mainly for the salary of the authors working for the MFFP 

主　　题：Ecosystem management Reference conditions Natural variability Resilience Fire cycle Age structure Forest dynamics Potential vegetation type Landscape ecology Theoretical natural landscape Present-day landscape 

摘      要：Background: In the contxt 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 forst 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 ***: 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 ***: 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 v