In managed forests, leaving retention trees during final harvesting has globally become a common approach to reconciling the often conflicting goals of timber production and safeguarding biodiversity and delivery of several ecosystem services. In Finland, the dominant certification scheme requires leaving low levels of retention that can benefit some specific species. However, species responses are dependent on the level of retention and the current low amounts of retention clearly do not provide the habitat quality and continuity needed for declining and red-listed forest species which are dependent on old living trees and coarse woody debris. Several factors contribute to this situation. First, the ecological benefits of the current low retention levels are further diminished by monotonous standwise use of retention, resulting in low variability of retention habitat at the landscape scale. Second, the prevailing timber-oriented management thinking may regard retention trees as an external cost to be minimized, rather than as part of an integrated approach to managing the ecosystem for specific goals. Third, the main obstacles of development may still be institutional and policy-related. The development of retention practices in Finland indicates that the aim has not been to use ecological understanding to attain specific ecological sustainability goals, but rather to define the lowest level of retention that still allows access to the market. We conclude that prevailing retention practices in Finland currently lack ecological credibility in safeguarding biodiversity and they should urgently be developed based on current scientific knowledge to meet ecological sustainability goals.

中文翻译：

---

低水平保留林业，认证和生物多样性：案例芬兰

在受管理的森林中，全球范围内，在最终采伐期间保留保留树木已成为协调木材生产常常相互矛盾的目标，保护生物多样性和提供多种生态系统服务的一种通用方法。在芬兰，占主导地位的认证计划要求保留较低的保留水平，以使某些特定物种受益。但是，物种的响应取决于保留的水平，目前的保留量很低，显然不能提供依赖于老活树和粗木屑的数量减少和列入红色名录的森林物种所需的栖息地质量和连续性。有几种因素导致这种情况。首先，单调性地逐个使用保留会进一步降低当前低保留水平的生态效益，因此在景观尺度上保留栖息地的变异性较低。其次，目前流行的以木材为导向的管理思想可能会将保留树木视为要降低的外部成本，而不是作为针对特定目标管理生态系统的综合方法的一部分。第三，发展的主要障碍可能仍然与体制和政策有关。芬兰养护做法的发展表明，其目的不是要利用生态学认识来实现特定的生态可持续性目标，而是要确定仍然允许进入市场的最低养护水平。