Nolet Philippe, Kneeshaw Daniel, Messier Christian, Béland Martin
Institut des Sciences de la Forêt tempérée (ISFORT) Université du Québec en Outaouais Ripon QC Canada.
Département des Sciences Biologiques Centre d'étude de la Forêt (CEF) Université du Québec à Montréal Montréal QC Canada.
Ecol Evol. 2017 Dec 20;8(2):1217-1226. doi: 10.1002/ece3.3737. eCollection 2018 Jan.
With an increasing pressure on forested landscapes, conservation areas may fail to maintain biodiversity if they are not supported by the surrounding managed forest matrix. Worldwide, forests are managed by one of two broad approaches-even- and uneven-aged silviculture. In recent decades, there has been rising public pressure against the systematic use of even-aged silviculture (especially clear-cutting) because of its perceived negative esthetic and ecological impacts. This led to an increased interest for uneven-aged silviculture. However, to date, there has been no worldwide ecological comparison of the two approaches, based on multiple indicators. Overall, for the 99 combinations of properties or processes verified (one study may have evaluated more than one property or process), we found nineteen (23) combinations that clearly showed uneven-aged silviculture improved the evaluated metrics compared to even-aged silviculture, eleven (16) combinations that showed the opposite, and 60 combinations that were equivocal. Furthermore, many studies were based on a limited study design without either a timescale (44 of the 76) or spatial (54 of the 76) scale consideration. Current views that uneven-aged silviculture is better suited than even-aged silviculture for maintaining ecological diversity and processes are not substantiated by our analyses. Our review, by studying a large range of indicators and many different taxonomic groups, also clearly demonstrates that no single approach can be relied on and that both approaches are needed to ensure a greater number of positive impacts. Moreover, the review clearly highlights the importance of maintaining protected areas as some taxonomic groups were found to be negatively affected no matter the management approach used. Finally, our review points to a lack of knowledge for determining the use of even- or uneven-aged silviculture in terms of both their respective proportion in the landscape and their spatial agency.
随着森林景观面临的压力不断增加，如果保护区得不到周边人工管理的森林基质的支持，就可能无法维持生物多样性。在全球范围内，森林管理采用两种广泛的方法之一——同龄和异龄造林法。近几十年来，公众对系统使用同龄造林法（尤其是皆伐）的压力不断增加，因为人们认为这种方法会产生负面的美学和生态影响。这导致了对异龄造林法的兴趣增加。然而，迄今为止，尚未基于多个指标对这两种方法进行全球范围的生态比较。总体而言，对于所验证的99种属性或过程组合（一项研究可能评估了不止一种属性或过程），我们发现有19种（23%）组合清楚地表明，与同龄造林法相比，异龄造林法改善了评估指标；11种（16%）组合显示出相反的情况；60种组合结果不明确。此外，许多研究基于有限的研究设计，没有考虑时间尺度（76项研究中有44项）或空间尺度（76项研究中有54项）。我们的分析并未证实当前认为异龄造林法比同龄造林法更适合维持生态多样性和生态过程的观点。我们的综述通过研究大量指标和许多不同的分类群，还清楚地表明，不能依赖单一方法，两种方法都需要，以确保产生更多积极影响。此外，综述清楚地强调了维持保护区的重要性，因为无论采用何种管理方法，都发现一些分类群受到了负面影响。最后，我们的综述指出，在确定同龄或异龄造林法的使用方面，无论是在景观中的各自比例还是其空间作用方面，都缺乏相关知识。
