How to conserve old growth forests?

The conservation of forest ecosystems requires the presence of all stages of succession (from pioneer stages to mature trees and to the decomposition stage). To conserve old-growth forests, the structure and dynamics of the forest have to be taken into account (which stages of succession are present in which part of the forest, how will species evolve on a parcel in the future, what is the link between the conditions and the species,…) . It is also important to pay attention to the restoration of the ecological processes and biodiversity of old-growth forests. Making society aware of the important values of old-growth forests is a must in order to protect and preserve these forests, as well as telling the public the reasons for the chosen management (for example, why dead wood is left in the forest).

More details about how to conserve old-growth forest?

The structure of old-growth forests can be restored by passive or active rewilding and/or restoration. Passive management means that nature takes its course and changes in forest development and structure depend on natural disturbances without any human intervention. The natural changes and developments that the forest goes through over time are determined by the intensity, type and frequency of the natural disturbance. Examples of these disturbing events are snowstorms, windstorms, insect outbreaks, etc. As a result, the structure of an old-growth forest can be formed with features such as standing dead trees, holes in the forest, downed tree trunks on the forest floor and pits and mounds from fallen trees. Depending on the characteristics of the original forest (naturalness level and previous management, fertility,…) passive management can take up from decades to centuries before the structure changes.

In active management, human intervention is required to form the old-growth forest structure. Careful planning aims to direct the development of standing dead trees, larger trees, diversity in tree sizes, different tree crowns and fallen trunks over time. Processes happen in a natural way (trees grow, die-off, their trunks form standing deadwood or fall down in the forest,…) while management interventions give direction towards the desired outcome, often by creating deadwood and a multi-age structure. This structure goes hand in hand with timber management, which is important for economic value. Forest management attempts to mimic natural disturbance in order to create old-growth forest characteristics. An active management impacts ecosystem functioning and is prefered for restoration of degraded forest systems rather than in a conservation plan. Although some trees are felled in active management, old trees are identified and remain in the canopy as they serve the old-growth forest structure and form an important habitat.
The conservation of old-growth forests requires taking into account the functionally linked network of strict forest reserves and protecting the isolated old-growth forest areas with closely managed buffer zones and corridors. Buffer zones serve to protect and conserve the isolated old-growth forest areas with their fauna and flora, and they create maximum connectivity between remote and old-growth forest areas

The buffer zones designated around beech forests by the UNESCO initiative on Ancient and Beech Forests of the Carpathians and Other Regions of Europe are an important landscape measure for the protection of isolated (old-growth) beech forests. In these buffer zones, rules are established for nature protection, conservation and restoration. The buffer zones are divided into two sub-zones. The first subzone, immediately surrounding the isolated old-growth forests, is meant as protection against negative external microclimatic effects. The second subzone provides for the preservation of forests to have a positive cooling effect on the mesoclimate. Negative impacts caused by man and climate change are beyond the protective function of buffer zones, but buffer zones do mitigate these impacts. Therefore, a buffer zone that is as large as possible and adequate protective management are important.

Important measures for the management of the buffer zone have been drawn up in a document by UNESCO and IUCN. The management is aimed at the maximum protection of the values of the protected area and its resistance and resilience to change. In addition, the World Heritage/Protection Area must be connected to other natural areas in the landscape in response to climate change-induced bio-shifts of fauna, flora and habitats. It is therefore necessary to maximize landscape-, evolutionary process-, ecological- and habitat connectivity. A buffer zone must always be located on land that is under direct or indirect control of the managing authority responsible for that area. Some management options that are then possible are: concluding a treaty that no management may be carried out or that only certain commercial harvests are allowed (specific restrictions). According to UNESCO, there is only one buffer zone, sub-zoning is only necessary for these buffer zones where different management regimes are applied. Here, the different buffer sub-zones are zoned separately and clearly demarcated in the field.

Kirchmeir and Kovarovics 2016; Kirchmeir et al. 2020
JRC Publications Repository – Mapping and assessment of old-growth and old-growth forests in Europe (
Guidance document on buffer zone management and buffer zone zonation, april 13 2021
Literature review on microclimate and edge effects in forest ecosystems
The buffer zone protects and connects the entire forest landscape, including beech stands, with other forests or natural ecosystems within the protected area. The connecting function of a buffer zone is very important for the connectivity between different forests and for the resistance and resilience (in populations) of ecosystems and natural processes. Through forest connectivity, species have the opportunity to expand their territory or to migrate when their former habitat is not suitable anymore. In regions where forests are highly fragmented, specific management rules can establish a functional ecological network to prevent or resolve forest fragmentation. This network aims to preserve and promote late-successional structural elements and late forest development stages, to ensure the connectivity and continuity in space. The network will thus consist of fallow and neglected plots, habitat trees and a larger amount of dead wood. In the network, the old-growth forests act as stepping stones for the habitat species, and the dead wood and habitat trees as an ecological matrix to connect the forest reserves (constituent parts) and the old-growth forests.
Handbook on sustainable forest management : Miha Varga, Bojan Kocjan, Domen Kocjan, Špela E. Koblar Habič, Urban Prosen- SLOVENIA FOREST SERVICE, Slovenia
A continuous forest cover, where no large parcels are left without canopy cover, is of great importance for a healthy forest ecosystem and the provision of ecosystem services. In this light, clearcutting (logging all the trees of a parcel at once) has a pernicious and long-term impact on the health of the ecosystem. Clear-cut areas are more susceptible to reduced water retention (due to too few trees), soil warming, soil erosion and nutrient run-off, which affects soil quality and can affect regrowth. Less invasive logging methods such as continuous canopy logging and reduced impact logging attempt to harvest with a minimal impact on the forest soil, the other trees, etc.
The economic value of the forests depends on the care of the stands to accelerate the development of quality timber. There are three main forestry methods used by the Slovenian Forestry School to ensure continuous forest cover, naturalness and multifunctionality of forests. The system of irregularly sheltered wood is the most widely used. It consists of successive cuttings interrupted by long regeneration periods. A second option is the plenter/selector system, where the cuts are executed in parcels of 0,3 ha maximum. This results in a heterogeneous forest structure with groups of trees of different ages. The free forestry method is the third method and combines principles of the plentering, selection and irregular shelterwood systems.

Handbook on sustainable forest management : Miha Varga, Bojan Kocjan, Domen Kocjan, Špela E. Koblar Habič, Urban Prosen- SLOVENIA FOREST SERVICE, Slovenia
Forests play a key role in the global carbon cycle by removing carbon dioxide (CO2) from the atmosphere. Growing forests absorb CO2 emissions and thus mitigate the climate crisis. Increasing biomass can increase CO2 uptake, enhance the carbon sequestration function and make forests more resilient to environmental changes, e.g. extreme weather events. Carbon certificates are introduced by the state contracting with private forestry companies, where money is allocated for the forest’s carbon sequestration function, rather than for income generation through logging. This will then be further closely monitored to ensure no logging is taking place. This is to promote carbon sequestration; increasing the stock of biomass and deadwood improves biodiversity conservation.

Handbook on sustainable forest management : Miha Varga, Bojan Kocjan, Domen Kocjan, Špela E. Koblar Habič, Urban Prosen- SLOVENIA FOREST SERVICE, Slovenia
Quiet areas are forest areas where fauna is not disturbed or endangered at all. There is limited human activity present such as logging, timber transport and recreational activities. These areas are important when nesting areas and dens of endangered species need to be protected (spatially quiet zones) or to limit forestry activities when certain species are vulnerable (temporally quiet zones). These quiet zones can only be mapped if the threatened species are monitored. Quiet zones will, among other things, provide foraging, resting, nesting and migration areas. Access to these areas can also be restricted and even closed. Quiet areas can help to preserve Natura 2000 species (species listed as vulnerable or endangered in Europe and that European countries are supposed to monitor and preserve through protected areas called Natura 2000). Some examples of vulnerable Natura 2000 species are Hazel grouse (Tetrastes bonasia) and Eurasian owl (Strix uralensis). Mapped quiet zones must be included in forest management plans in order to protect fauna in the best possible way.

Handbook on sustainable forest management : Miha Varga, Bojan Kocjan, Domen Kocjan, Špela E. Koblar Habič, Urban Prosen- SLOVENIA FOREST SERVICE, Slovenia