Value of mature forest

Within the forest, the mature stands are those fragments of forest that have remained untouched by human intervention, following their own natural evolution process. In the ageing process, these stands acquire singular features:

1. Very big and very old trees that offer shelter

These stands contain exceptional trees, giants of over 1 metre in diameter. These trees play an essential ecological role. Their advanced age has given them a multitude of hollows and cracks that are populated by hundreds of species of fungi and lichens, as well as birds, bats and insects.

2. Forest gaps that enable regeneration

Minor disturbances (such as the collapse of big trees) open up gaps in the forest canopy letting in more sunlight. In these gaps, the forest recommences its regeneration process.

3. Deadwood, standing and lying on the ground

Dead trees, whether they remain standing or their massive trunks lie on the forest floor, are the habitat of a multitude of species specialised in decomposing wood. This deadwood is usually cleared away in forests dedicated to timber production, but mature forests contain abundant deadwood, coarse or small, and at different stages of decomposition.

4. Trees of different sizes and a variety of species

In managed timber-producing forests, trees of all ages are rarely found together. In old-growth stands, however, individuals of all different ages coexist, from the youngest to their great hundred-year-old ancestors. Trees and shrubs of different species mix together in a more complete and varied ecosystem. And also, more importantly, more resistant to alterations due to climate change.

Old-growth forest: characteristics and conservation value

Mature Forest. Frequently asked question

Forests’ life cycle (sometimes referred to as “sylvogenetic cycle” or more commonly as “forest dynamics”) comprises several stages along a time line, from its early establishment to maturity and senescence. When observed at the landscape level, a forest in a favourable conservation status should have a mosaic of several or all of these stages.

However, due to the intensity of human uses in the Mediterranean forests since time immemorial, there are very few remaining examples of old-growth forests, free from human interference. In certain types of forests probably there are none such old-growth remnants.

Action B3 is aimed at implementing a protocol for the identification of old-growth (or near-old-growth) forests, which could be used as a reference for assessing the conservation status of the forest habitats in Spain:

• STAGE 1 – Prospection: It requires a short description, with qualitative or semiquantitative indicators, that may be easily fulfilled by trained personnel. It may be executed by forest specialists and rangers in a first approach to identify candidate forests.
• STAGE 2 – Characterization: Quantitative indicators about the forest’s structural properties and human impacts is proposed to characterize each candidate forest stand. This work involves taking measurements on the field. Two alternative methods, based on sampling plots or transects, are proposed.

Sampling protocols and field sheets may be downloaded HERE (Spanish version)

Results from this characterization work throughout Spain are compiled, organized in a data base, and made available on the web by EUROPARC-España members, so that a National Network of Reference Forests is established. Advances in this Network can be checked here.

The Network of Reference Stands brings together a set of stands representative of the most natural situations for most of the forest Habitats of Community Interest present in Spain.

Among other applications, these stands can be used to determine the conservation status of forest habitats, or serve as a model for a forestry with biodiversity conservation objectives.

Access to the database is done through the REDBOSQUES tool, which allows:

• Visualize the location of the stands, both those in the prospecting phase (phase I) and in the identification phase (phase II).
• Consult the global values ​​of the maturity indices, human footprint and spatial integrity for each stand (by clicking on each stand).
• Compare the characteristics of each stand with the reference stands corresponding to that habitat, with detailed information for each criterion and indicators of maturity, human footprint and spatial integrity.
• Compare the characteristics of a stand with the values ​​of the National Forest Inventory (IFN3) corresponding to that habitat, with detailed information for each criterion and maturity indicators.

The network is built collaboratively. If you want to provide information of relevance to the network of stands, you can contact through redbosques@fungobe.org.