What measures can we take?
Compiled by EFI with participation of Elisabeth Pötzelsberger, Jürgen Bauhus, Bart Muys, Sven Wunder, Michele Bozzano, Anna-Maria Farsakoglou, Andreas Schuck, Marcus Lindner and Katharina Lapin
To ensure the conservation and restoration of forest biodiversity it will be crucial to deal with all the external and internal pressures mentioned above. Here, we restrict our discussion to those important forestry-related measures to support biodiversity that we regard as the most effective from a policymaker’s as well as forest practitioner’s perspective.
Targeted forestry measures
There is now a good body of evidence for a range of approaches to better integrate biodiversity conservation into forest management e.g. through adopting natural processes, diversifying forest structure and composition and integrating old-growth forest elements (Krumm et al. 2020) or through special treatment and conservation of genetic conservation units across Europe, following the pan-European strategy for genetic conservation of forest trees (De Vries et al. 2015).
Emphasis should be given to ensure a diversity of forest conditions at stand and landscape level. At stand level diversity of conditions and structure can be promoted through e.g. the tree species mixture, veteran trees, the shrub, tree and herbal understorey, and standing and lying deadwood and at landscape level through a variety of forest management and forest development stages (including the sapling/regeneration stage preferred by e.g. less shade-tolerant plants or free breeding birds) and no-intervention areas. Together, this maximises within-stand, across-stand and landscape diversity (alpha, beta, gamma diversity) benefiting a wide variety of species groups (Hilmers et al. 2018; Schall et al. 2018).
It is imperative that restoration practice apply multidisciplinary approaches that consider important but previously neglected factors like the genetic composition (diversity and adaptedness) of tree populations to ensure both the short and the long-term success.
So called ‘integrative forest management approaches’ that allow for the retention and active restoration of old-growth attributes, old-growth islands and rare forest types in sustainably managed forests should receive more attention in the current political debate as a complementary measure for biodiversity protection (Aggestam et al. 2020). These forests will also provide important corridors among strictly protected areas.
Due to the fundamental changes in site conditions that climate change is causing, it will also be important to connect biodiversity restoration with forest adaptation - applying ‘prestoration’ (Butterfield et al. 2017) – as a dynamic approach to ensure continued ecosystem functioning and habitat provision under changing climatic conditions. Furthermore, it is imperative that restoration practices consider ogenetic composition (diversity and adaptedness) of tree populations, which impacts on forests’ survival, adaptation and evolution under changing environmental conditions, ecosystem stability and forest resilience (Alfaro et al. 2014; Bozzano et al. 2014). Future management options to adapt forests to climate change heavily rely on the availability of appropriate forest genetic resources, but in turn sustainable forest management also needs to consider genetic diversity at all levels. The use of forest reproductive material that is genetically suited for a specific site requires a sound knowledge about its identity, adaptive traits and adaptation potential. Work still needs to be done on the identification and characterization of forest reproductive material, and science-based tools should be further developed and made available broadly to support end-users and the regulating framework in the decision making, e.g. with recommendations on suitable provenance, indicators for genetic diversity and results of genetic tests (Gömöry et al. 2021).
Figure: Idealised integratively managed forest landscape that integrates segregative elements such as special biotopes, strict reserves, old-growth/old forest islands, linear structures but also habitat trees and deadwood that are spatially embedded within a matrix of managed forests (taken from Krumm et al., 2013). The forest matrix may be managed by close-to-nature management principles, or by other forms of sustainable forest management that would allow for different forest development stages including the more open regeneration phase to co-exist next to each other at landscape level (development stages for simplicity not separately shown).
There are different forest protection approaches with differing protection goals, ranging from the protection of single veteran trees up to large wilderness regions where natural processes can take place freely. Today, the remaining primary and old-growth forests in Europe receive particular attention, and deserve strict protection due to their very low remaining coverage and the rare habitat types they offer (Sabatini et al. 2020). While the current value of other protected forest areas for the conservation of biodiversity, like the Natura 2000 network, is also largely undebated, to maintain biodiversity long-term, it is necessary to allow for potential shifts in species ranges, communities and habitats across the landscape as environmental conditions change, and to identify and protect species, habitats and regions most at risk (Thomas et al. 2004; Willis and Birks 2006).
It is important to recognize that the habitat types we have designated to date are a construct and will not persist unchanged in the future. Protected areas mostly have not been designed to account for the long-term and large-scale dynamics of ecosystems as part of dynamic landscapes (Bengtsson et al. 2003), and the selection of reserve areas has not been made with climate change in mind (Haslet et al. 2010). Particularly in Europe’s distinct cultural landscape, strictly protected areas account for only a small proportion of land, and climate change limits protected areas’ ability even more to capture the dynamic development of ecosystems. It is estimated that in temperate deciduous and mixed forests globally, approximately 45% of all protected areas will experience unprecedented climatic conditions by 2070 (Hoffmann et al. 2019). In most cases, the expected range shifts of species due to climate change cannot occur within protected area boundaries (Araujo et al. 2011).
It is therefore key to think and plan species and habitat conservation across the entire forested landscape and all types of forest tenures. Only a functioning ecological network will allow climate-induced distribution shifts to preserve biodiversity (Fuchs et al. 2007, 2010; Jongman et al. 2004). Key elements of the biotope network include appropriately sized high-quality core areas, stepping stones and corridors (climatically suitable habitats that provide migration options), but also the surrounding forest matrix should be developed to optimize permeability for migration (Fahrig 2013, 2019, Krosby et al. 2010). In Europe, such an ecological network can only be developed if forests of all tenure types can be included. Incentives for private, communal or municipal forest owners need to be provided to ensure the future development and adaptation of their forests occurs in support of such a biotope network.
Forest owners are key stakeholders for the restoration and conservation of forest biodiversity. As well as the issue of capacity, a crucial question is what intrinsic motivation diverse European forest owners have to fully consider biodiversity conservation beyond the kind of biodiversity required for a healthy production forest. Satisfying additional biodiversity demands may lead to income losses, i.e. opportunity costs of foregoing profits in less diverse yet profitable systems through different choices of tree species, harvesting decisions, or the set-aside for conservation of old-growth. There may also be other provision costs, e.g. controlling access to the forestland for external agents potentially degrading biodiversity through signposting, fencing, or monitoring.
Extrinsic incentives can cover these opportunity costs of biodiversity conservation measures. The classical tool is state subsidies for reforestation, which may require e.g. a certain level of tree species diversity. This has in recent decades been developed further into the concept of payments for environmental services (PES) to encourage forest owners to be proactive in enhancing forest biodiversity (Engel et al. 2008, Ferraro and Kiss 2002; Wunder and Wertz-Kanounnikoff 2009). PES has been applied in public PES schemes e.g. in China, Costa Rica, Ecuador, and Peru, and by private conservation NGOs and international organisations in North America and in the Global South (Barbier et al. 2018; Salzman et al. 2018). Impact evaluations have also shown that PES interventions globally seem to be successful (Wunder et al. 2020).
In Europe, forest biodiversity PES schemes have been rare. We have seen more forest PES initiatives focused on watershed, landslide and avalanche protection (e.g. in Switzerland, Austria, Italy, Germany) (Viszlai et al. 2016), whereas multiple experiences exist with the use of agri-environmental payments to safeguard biodiversity on private productive lands (Hanley and White 2014). Good examples for PES for biodiversity, however, do exist, starting with smaller pilots like protecting ‘singular’ (old) forests in Catalonia, to larger programmes in Finland and Sweden, changing forest management towards greater provision of recreational and biodiversity-related benefits. For instance, the Forest Biodiversity Programme for Southern Finland (METSO) has paid compensations to voluntarily enrolled forest owners since 2008 to take concrete management measures to enhance biodiversity. METSO’s aim is to halt the ongoing decline in the biodiversity of forest habitats and species. By 2025, about 82,000 hectares of high-value forest habitats in private, commercially managed forests will be protected by fixed-term PES agreements.
The way in which biodiversity PES contracts are allocated also matters for cost efficiency. A promising pilot has recently been carried out in Central Jutland, Denmark, where PES contracts have been granted using reverse auctions: landowners with the lowest bids offering their forests for specific conservation action will win the contract. In this way, more biodiversity benefits can be bought for each unit of taxpayer money. Similar voluntary competitive mechanisms to improve biodiversity protection outcomes through reverse auctions will be tested in Belgium; both cases form part of the H2020 project SINCERE.
At the EU level, dedicated funds for landowner incentives under Natura 2000, LIFE+, and Rural Development Programme have mostly been under-utilized, mainly due to landowner-perceived transaction costs and the bureaucratic difficulties of accessing them. A more extensive use of an EU-based forest PES scheme should be aimed for in the future, to encourage better forest management to control a range of threats to forest resilience, e.g. extreme forest wildfires, which in turn also threaten forest biodiversity.
Beyond PES, other financing and incentive tools exist to enhance forest biodiversity. Forest certification, for example, aims to have final consumers pay price premiums to reward labelled producers undertaking biodiversity-friendly forest management. Another tool can be biodiversity offsets, which accept losses of biodiversity in a place of (high-value) economic development, but provide resources for compensatory biodiversity conservation and restoration in other sites (Vaissiere et al. 2020). Finally, green bonds are another tool for investors to pay for frontloaded forest management actions, which environmental service beneficiaries will pay back only later, but this tool has more been used for e.g. wildfire-preventing forest management, rather than directly focused on biodiversity actions (Ehlers and Packer 2017).