Does a minimal intervention approach threaten the biodiversity of protected areas? A multi-taxa short-term response to intervention in temperate oak-dominated forests
Introduction
Biodiversity conservation has long been a goal of European conservation policy (CBD, 2010, CEC, 1998). However, despite the fact that more than 25% of European land is afforded some level of protection for conservation, biodiversity continues to decline (EEA, 2009). One factor contributing to this decline may be unsuitable management practices in protected areas, or more specifically, the insufficient application of evidence-based conservation recommendations (Sutherland et al., 2004). A major concern involves the selection of efficient strategies for the conservation of biodiversity in forest ecosystems.
Today, most forests in Europe are closed, shady habitats. This contrasts with their past state, which was much more open and dynamic. The open structure was maintained by disturbances such as grazing and fires (Adámek et al., 2015, Bengtsson et al., 2000, Niklasson et al., 2010, Rackham, 1998, Szabó, 2010, Vera, 2000). These disturbances were later substituted by human silvicultural practices such as wood pasturing, controlled burning and coppicing. Wood pasturing and burning prevented full canopy closure and led to the formation of open, park-like habitats with numerous open-grown trees. In coppices, trees were usually cut down every 7–20 years (Szabó, 2010), which maintained a cyclical pattern of extreme changes in ground-level light penetration (Buckley, 1992, Joys et al., 2004). Traditionally managed woodlands were thus open, sunny, heterogeneous mosaics of forest in various stages of succession, which harboured a high richness of animals and vascular plants (Hédl et al., 2010, Benes et al., 2006, Bengtsson et al., 2000, Bugalho et al., 2011, Spitzer et al., 2008, Vodka and Cizek, 2013, Warren and Thomas, 1992).
However, the traditional management practices maintaining these disturbance regimes have largely been abandoned in most of Europe, especially over the last 200 years (Bergmeier et al., 2010, Müllerová et al., 2014, Müllerová et al., 2015, Tárrega et al., 2009). The formerly common, open woodlands have gradually been transformed into high closed-canopy forests in order to satisfy increased demand for timber or due to secondary succession. Due to the absence of regular disturbances, increases in canopy closure have also occurred in forests in protected areas. For instance, within nature reserves in the south-east of the Czech Republic, the expansion of closed-canopy forest has reduced the cover of open woodlands from 68.5% to 14.1% between 1938 and 2009 (Miklín & Čížek, 2013). Similar reductions have occurred across the European continent (Hartel and Plieninger, 2014, Rackham, 2003). As a result, species composition in forests has shifted from light-demanding and oligotrophic species towards more generalist, mesic and shade-tolerant species (Hédl et al., 2010, Kopecký et al., 2013, Van Calster et al., 2008, Van der Werf, 1991, Vild et al., 2013). Many species associated with open woodlands, including numerous plants, fungi, and animals that were common in the past have thus became rare or endangered.
In commercial forests, the maintenance of high canopy closure is economically justifiable, although even in these forests some forms of management may result in short-term canopy openings (e.g. selection cutting, thinning) (Pawson et al., 2013, Verschuyl et al., 2011). On the other hand, protected areas are mostly dedicated to biodiversity conservation. Management of protected forests therefore must consider the requirements of the species that inhabit those forests, including endangered species. Active management measures restoring or maintaining the open structure of forests in European protected areas are surprisingly rare (but see for instance Plieninger et al. (2015) for the use of wood pasturing), despite the fact that their need is emphasized by many studies concerning biodiversity of temperate forests (Götmark, 2013). Yet while active approaches to forest conservation management are continuously recommended by the scientific community, the “strict forest reserve” concept (Schultze et al., 2014) which prevents intervention is a standard practice applied to over 3 million hectares (or about 1.7% of forested area) in Europe (COST Action E4, 2000). Although traditionally managed open woodlands require a special approach to nature conservation (Götmark, 2013, Lindbladh et al., 2007), policies often consider coppicing or wood pasturing as undesirable disturbances to the “naturalness” of forests (Miklín and Čížek, 2014). Numerous studies compared the biodiversity of unmanaged (minimal intervention approach) and commercially managed forests concluding that minimal intervention favours biodiversity (Lassauce et al., 2013, Martikainen et al., 2000, Paillet et al., 2010). In protected areas, however, the choice is often between active conservation measures and minimal intervention approach rather than between the minimal intervention and commercial management. Yet there is little information comparing the effects of active conservation measures and the minimal intervention (Franc and Götmark, 2008, Götmark, 2013). Managers of protected forests thus lack basic information needed for qualified management decisions.
In order to quantify the effects of minimal intervention and active management approaches on biodiversity of protected forests, we carried out a multi-taxa study in the oak-dominated forests of Podyji National Park (Czech Republic). Twelve experimental clearings were created in unmanaged, closed-canopy forests of the core zone of the park. In the first season after their creation, eight model groups (butterflies, moths, epigeic, floricolous and saproxylic beetles, reptiles, birds and vascular plants) were sampled in the clearings and in adjoining reference habitats (including closed-canopy forest, open forest, forest edge, and meadow). To assess the effect of the active intervention we compared the species richness and the species composition of the model groups among the newly created clearings and the reference habitats. We also assessed the importance of individual habitats for sustaining threatened species in the sampling area.
Section snippets
Study area and design
This study was carried out in Podyji National Park (South Moravia, Czech Republic) (48°50′56″N, 15°53′13″E), an area covering 63 km2 of the Dyje River canyon (ca 300 m a.s.l.). The canyon is characterised by nutrient poor, shallow soils. Until the Second World War, a large part of the area was managed by livestock grazing and coppicing, which kept the landscape open. After the war, these practices were abandoned, and secondary succession has led to an increase in canopy closure. Today, the area
Results
We recorded 2003 butterflies from 66 species (15 of them threatened), 10,462 moths from 403 species (53 threatened), 6055 epigeic beetles from 89 species (13 threatened), 2927 saproxylic beetles from 293 species (58 threatened), 1039 floricolous beetles from 62 species (7 threatened), 1296 reptiles from 7 species (4 threatened), 806 birds from 49 species (9 threatened), and 449 species of vascular plants (64 threatened). Mean number of threatened species found in particular habitats is
Discussion
This is one of the first studies (see also Götmark, 2013, Rancka et al., 2015) to investigate the effect of active interventions in temperate closed-canopy forest that used a large number of model groups with different life histories. The design of the study also allowed for an assessment of the importance of connectivity of open wooded habitats. Other studies show that interventions to closed-canopy forests, like partial cutting, may have positive effect on some groups of organisms (e.g.
Conclusions
The present study shows that shortly after intervention, valuable habitats for woodland biodiversity were created in closed-canopy temperate forests. Further research should investigate the importance of such habitats in the longer term. Information on how these communities change throughout secondary succession, or the best policies to maintain the suitability of the habitats for the studied groups (e.g. by repeated cutting after several years) are needed for robust conservation
Acknowledgements
We would like to thank the Administration of Podyji NP, Carl Wardhaugh for English correction, and two anonymous reviewers for their constructive comments. The study and its authors were supported by the Czech Science Foundation (P504/12/1952 and P505/10/2167), GAJU (046/2014/P), and by the projects CZ.1.07/2.3.00/20.0064 (PS, MP, MZ and LC) and CZ.1.07/2.3.00/30.0040 (RB and MSv) co-financed by the European Social Fund and the state budget of the Czech Republic. The authors have declared that
References (66)
- et al.
Forest fires within a temperate landscape: a decadal and millennial perspective from a sandstone region in Central Europe
For. Ecol. Manage.
(2015) - et al.
Intensive game keeping, coppicing and butterflies: the story of Milovicky Wood, Czech Republic
For. Ecol. Manage.
(2006) - et al.
Biodiversity, disturbances, ecosystem function and management of European forests
For. Ecol. Manage.
(2000) - et al.
Modelling habitat and spatial distribution of an endangered longhorn beetle – a case study for saproxylic insect conservation
Biol. Conserv.
(2007) - et al.
Effects of coppicing on butterfly communities of woodlands
Biol. Conserv.
(2013) - et al.
Openness in management: hands-off vs partial cutting in conservation forests, and the response of beetles
Biol. Conserv.
(2008) Habitat management alternatives for conservation forests in the temperate zone: review, synthesis, and implications
For. Ecol. Manage.
(2013)- et al.
Biodiversity of most dead wood-dependent organisms in thermophilic temperate oak woodlands thrives on diversity of open landscape structures
For. Ecol. Manage.
(2014) - et al.
Influences of deer browsing, coppice history, and standard trees on the growth and development of vegetation structure in coppiced woods in lowland England
For. Ecol. Manage.
(2004) - et al.
Species richness of Coleoptera in mature managed and old-growth boreal forests in southern Finland
Biol. Conserv.
(2000)
Erasing a European biodiversity hot-spot: open woodlands, veteran trees and mature forests succumb to forestry intensification, succession, and logging in a UNESCO Biosphere Reserve
J. Nature Conserv.
The rise and fall of traditional forest management in southern Moravia: a history of the past 700 years
For. Ecol. Manage.
Coppice abandonment and its implications for species diversity in forest vegetation
For. Ecol. Manage.
Wood-pastures of Europe: geographic coverage, social–ecological values, conservation management, and policy implications
Biol. Conserv.
Does closure of traditionally managed open woodlands threaten epigeic invertebrates? Effects of coppicing and high deer densities
Biol. Conserv.
The need for evidence-based conservation
Trends Ecol. Evol.
Driving forces of stability and change in woodland structure: a case-study from the Czech lowlands
For. Ecol. Manage.
Abandonment and management in Spanish dehesa systems: effects on soil features and plant species richness and composition
For. Ecol. Manage.
Diverging effects of overstorey conversion scenarios on the understorey vegetation in a former coppice-with-standards forest
For. Ecol. Manage.
Biodiversity response to intensive biomass production from forest thinning in North American forests – a meta-analysis
For. Ecol. Manage.
Experimental restoration of coppice-with-standards: response of understorey vegetation from the conservation perspective
For. Ecol. Manage.
The effects of edge-interior and understorey-canopy gradients on the distribution of saproxylic beetles in a temperate lowland forest
For. Ecol. Manage.
Geobotanical survey of woodpasture habitats in Europe: diversity, threats and conservation
Biodivers. Conserv.
Diversity of moth communities (Insecta: Lepidoptera) in differently-structured oak-hornbeam forests: a comparison of different phases of succession in coppice with standards and forests with high standard trees
Ecology and Management of Coppiced Woodlands
Mediterranean cork oak savannas require human use to sustain biodiversity and ecosystem services
Front. Ecol. Environ.
Plant diversity in a managed temperate deciduous forest: understorey response to two silvicultural systems
J. Appl. Ecol.
Value of semi-open corridors for simultaneously connecting open and wooded habitats: a case study with ground beetles
Conserv. Biol.
Cited by (66)
Bark beetle outbreak and biodiversity in commercial spruce plantations: Responses of four model groups
2024, Forest Ecology and ManagementImportance of stochastic assembly processes influencing beetle communities increases after logging
2023, Forest Ecology and ManagementLegacies of historical management practices in the large-scale distribution pattern of oak-hornbeam woodlands in Czechia
2023, Forest Ecology and ManagementOpening the canopy to restore spider biodiversity in protected oakwoods
2023, Forest Ecology and ManagementThreats, biodiversity drivers and restoration in temperate floodplain forests related to spatial scales
2023, Science of the Total Environment