The Potential of Production Forests for Sustaining Lichen Diversity: A Perspective on Sustainable Forest Management

Abstract

There is a critical gap in our knowledge about sustainable forest management in order to maintain biodiversity with respect to allocating conservation efforts between production forests and set-asides. Field studies on this question are notably scarce on species-rich, poorly detectable taxon groups. On the basis of forest lichen surveys in Estonia, we assessed the following: (i) how much production stands contribute to maintaining the full species pool and (ii) how forest habitat conditions affect this contribution for habitat specialist species. The field material was collected in a "semi-natural forestry" system, which mitigates negative environmental impacts of even-aged forestry and forestry drainage by frequently using natural regeneration, tree retention, and low intensity of thinnings. We performed standard-effort surveys of full assemblages of lichens and allied fungi (such as non-lichenized calicioid and lichenicolous fungi) and measured stand structure in 127 2 ha plots, in mainland Estonia. The plots represented four management stages (old growth, mature preharvest forests, clear-cut sites with retention trees, and clear-cut sites without retention trees). The 369 recorded species represent an estimated 70% of the full species pool studied. Our main finding was that production forests supported over 80% of recorded species, but only one-third appears tolerant of management intensification. The landscape-scale potential of production forests through biodiversity-friendly silviculture is approximately twice as high as the number of tolerant species and, additionally, many very rare species depend on setting aside their scattered localities. The potential is much smaller at the scale of individual stands. The scale effect emerges because multiple stands contribute different sets of sensitive and infrequent species. When the full potential of production forests is realized, the role of reserves is to protect specific old-growth dependent taxa (15% to 20% of the species pool). Our study highlights that production forests form a heterogeneous and dynamic target for addressing the biodiversity conservation principle of sustainable forest management. of 23improving and mitigating forest management techniques, and effective landscape planning [2,3]. Despite such an understanding and several political and market mechanisms to enforce SFM [4], forest biodiversity continues to decline even in those regions that have a strong political commitment to SFM, such as the European Union [5].A critical gap in knowledge about maintaining forest biodiversity along with other forest use is how to allocate conservation efforts between production forests and set-asides of different type and size [6][7][8]. This gap remains partly rooted in incomplete knowledge on most forest organisms and their responses to management practices [9], which weakens conservation arguments in stakeholder processes and, specifically, makes these dependent on approaches to the precautionary principle [10]. A promising approach is to define a set of ...

Habitat Models of Focal Species Can Link Ecology and Decision-Making in Sustainable Forest Management

“…In analyses on lichenized and wood-inhabiting fungi, we have concluded that focal-species criteria can be met in ca. 2% of the Estonian forest species pool [92,93]. This points at an order of magnitude of a few hundred focal species to be considered for forestry in this country.…”

“…For example, forest fungal surrogates have been explored in many studies [90], including the matching of selected wood-inhabiting species with threats [91,92]. Specialized lichens appear suitable for guiding multiple management dimensions [93], but spatial models for that remain scarce (Table 1). Modeling for decision-making may have thus contributed to the taxonomic bias in SFM, which is usually attributed to insufficient stakeholder knowledge [94].…”

“…However, rapid tree growth also accelerates structural recovery after abandoned management or long rotations based on natural regeneration [170,173,174]. Many well-dispersing old-forest species can colonize such forests at longer rotations [92,175], while others remain excluded due to the absence of old-forest structures [93] or (poor dispersers) lack of local refugia [176].…”

External management effects on the stand structure of protected forest patches

“…Thus, a criterion for site selection was the availability of earlier (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012) information (e.g. Andersson et al, 2003;Lõhmus & Lõhmus, 2019;Runnel & Lõhmus, 2017).…”

Biodiversity Conservation in Managed Forests

“…Papers by Re ňco et al [5] and Lõhmus and Lõhmus [6] document species diversity of species-rich, but understudied species in Eastern European forests. Re ňco et al studied the response of soil nematodes and microbial communities to windstorms in beech and spruce forests.…”