Natural Disturbance-Based Forest Management: Moving Beyond Retention and Continuous-Cover Forestry

Global forest area is declining rapidly, along with degradation of the ecological condition of remaining forests. Hence it is necessary to adopt forest management approaches that can achieve a balance between (1) human management designs based on homogenization of forest structure to efficiently deliver economic values and (2) naturally emerging self-organized ecosystem dynamics that foster heterogeneity, biodiversity, resilience and adaptive capacity. Natural disturbance-based management is suggested to provide such an approach. It is grounded on the premise that disturbance is a key process maintaining diversity of ecosystem structures, species and functions, and adaptive and evolutionary potential, which functionally link to sustainability of ecosystem services supporting human well-being. We review the development, ecological and evolutionary foundations and applications of natural disturbance-based forest management. With emphasis on boreal forests, we compare this approach with two mainstream approaches to sustainable forest management, retention and continuous-cover forestry. Compared with these approaches, natural disturbance-based management provides a more comprehensive framework, which is compatible with current understanding of multiple-scale ecological processes and structures, which underlie biodiversity, resilience and adaptive potential of forest ecosystems. We conclude that natural disturbance-based management provides a comprehensive ecosystem-based framework for managing forests for human needs of commodity production and immaterial values, while maintaining forest health in the rapidly changing global environment.

Change of Ellipsoid Biovolume (EV) of Ground Beetles (Coleoptera, Carabidae) along an Urban–Suburban–Rural Gradient of Central Slovakia

Changes in the structure of ground beetle communities indicate environmental stability or instability influenced by, e.g., urbanization, agriculture, and forestry. It can affect flight capability and ellipsoid biovolume (EV) of ground beetles. Therefore, we analyzed ground beetles in various habitats. In the course of the period from 2015 to 2017, we recorded in pitfall traps 2379 individuals (1030 males and 1349 females) belonging to 52 species at six localities (two rural, two suburban, two urban). We observed the decrease in the average EV value and morphometric characters (length, height, and width of the body) of ground beetles in the direction of the rural–suburban–urban gradient. Our results also suggest a decrease in EV of apterous and brachypterous species and an increase in macropterous species in the urban and suburban landscapes near agricultural fields. The increasing EV of apterous and brachypterous species and the decreasing of macropterous species was observed in rural landscape conditions with not continuous cover forestry and partial forest management. The creation of habitat fragments in urbanized conditions is key to maintaining the average EV in apterous and brachypterous species in urban and suburban landscapes.

Multi-objective forestry increases the production of ecosystem services

Boreal forests produce multiple ecosystem services for the society. Their trade-offs determine whether they should be produced simultaneously or whether it is preferable to assign separate areas to different ecosystem services. We use simulation and optimization to analyse the correlations, trade-offs and production levels of several ecosystem services in single- and multi-objective forestry over 100 years in a boreal forest landscape. The case study area covers 3600 ha of boreal forest, consisting of 3365 stands. The ecosystem services and their indicators (in parentheses) considered are carbon sequestration (forestry carbon balance), biodiversity (amount of deadwood and broadleaf volume), economic profitability of forestry (net present value of timber production) and timber supply to forest industry (volume of harvested timber). The treatment alternatives simulated for each of the stands include both even-aged rotation forestry (thinning from above with clear cut) and continuous cover forestry regimes (thinning from above with no clear cut). First, we develop 200 Pareto optimal plans by maximizing multi-attribute utility functions using random weights for the ecosystem service indicators. Second, we compare the average level of ecosystem services in single- and multi-objective forestry. Based on our findings, forestry carbon balance and the amount of deadwood correlate positively with each other, and both of them correlate negatively with harvested timber volume and economic profitability of forestry. Despite this, the simultaneous maximization of multiple objectives increased the overall production levels of several ecosystem services, which suggests that the management of boreal forests should be multi-objective to sustain the simultaneous provision of timber and other ecosystem services.

Profitability of continuous cover forestry in Norway spruce-dominated peatland forest and the role of water table

Continuous cover forestry (CCF) is expected to reduce the negative environmental impacts of peatland forestry in comparison to rotation forestry (RF), but the unknown profitability of CCF on peatlands limits its application in practice. The profitability of CCF was analysed by simulating management scenarios with a process-based ecosystem model, EFIMOD, which was complemented to describe the interplay between tree growth and water table depth, which is typical of peatland forests. A variety of harvest intervals and post-harvest basal areas for a mature Norway spruce-dominated stand was simulated on a nutrient-rich peatland site. Conventional RF was simulated for comparison. CCF provided a higher profit than RF. The best financial performance was obtained with a 15-year harvest interval regardless of interest rate, although the overall profitability of CCF depended on the used interest rate. Ditch network maintenance was needed to maintain the stand growth only when the post-harvest basal area was smaller than 10 m² ha⁻¹. There were many CCF scenarios in which the difference in the net present value of harvest revenues was within ten percent compared with the best CCF scenario. Hence, there are many relatively well-profitable CCF harvesting alternatives for forest management in boreal spruce-dominated peatland forests.