Forest: deadwood (SEBI 018) - Assessment published May 2010
The quantity of deadwood in Europe's forests, which is an important indicator for forest biodiversity, has strongly decreased since the middle of the nineteenth century due to intense forest exploitation and widespread burning of small wood and other debris. Since 1990, however, an overall increase in this indicator by about 4.3 % has been observed and this may be due to increased compliance with sustainable forest management principles. These principles should be considered in view of increasing wood demand, e.g. for renewable energy production.
How much deadwood is present in European forests?
Deadwood in Pan-European forests, 1990-2005
Note: In the period 1990-2005, an overall increase in dead wood by about 4.3 % was observed in the pan-European region (EEA, 2009), a sign of more biodiversity-friendly management.
FAO, 2005. Global Forest Resources Assessment 2005 Country tables Biomass stock in forest and other wooded land. www.fao.org/forestry/32100/en/ [Accessed 27 April 2009].
SEBI indicators, 2010 - SEBI indicator 18.
Deadwood per hectare in forests, 2005
Note: How to read the graph: in 2005, Estonian forests averaged 6 m3/ha of standing deadwood and 5 m3/ha of lying deadwood.
Deadwood (coarse woody debris) is a proxy indicator for invertebrate biodiversity, since it is a habitat for a wide array of organisms. Deadwood decomposition plays a key role in the recycling of nutrients and organic matter as well as the creation of a wide variety of micro sites for regeneration of plant species and the creation of a wide variety of habitats for other organisms. The amount of deadwood is an excellent indicator of the conservation value of a forest.
Quantities of deadwood in Europe have strongly decreased between the middle of the nineteenth century and latter part of the twentieth century due to intense forest exploitation and widespread burning of small wood and other debris. Moreover, classical forest management is usually based on rotations shorter than the natural longevity of tree species. The number of large old trees, which are more likely to be a source of dead wood in the forest, is therefore relatively low. Nowadays, however, many European countries have launched initiatives to increase the amount of deadwood, though not all increases are the esult of biodiversity considerations. Available evidence suggests that the amount of deadwood increased in the pan-European region by about 4.3 % in the period 1990 - 2005. The deadwood stock in forests might decline again, however, as wood demand increases for such things as renewable energy production. Overall, deadwood in most European countries remains well below optimal levels from a biodiversity perspective.
The amount of deadwood that will naturally accumulate in forests varies greatly depending on boreal forest) up to 216 m3/ha (mixed mountain forest in central Europe) (Hahn and Christensen, 2004). In a study of boreal forests in Fennoscandia, deadwood volumes ranged from 19 m3/ha up to 145 m3/ha with values at the lower end of the range at higher latitudes near the timberline (Siitonen, 2001). In managed forests deadwood volumes can range from 2 m3/ha to 10 m3/ha (Siitonen, 2001).
In some areas the accumulation of deadwood may not be desirable, for example where the risk of insect pests (such as invasions of bark beetles) or forest fires is considered unacceptable. This occurs in Mediterranean coniferous plantations where deadwood must be removed to avoid fires.
- MCPFE, 2007. State of Europe's Forests 2007. Jointly prepared by the Ministerial Conference on the Protection of Forests in Europe Liaison Unit Warsaw, UNECE and FAO. Available at: http://www.mcpfe.org/files/u1/publications/pdf/state_of_europes_forests_2007.pdf [Accessed 23 June 2008]
- Hahn, K. and Christensen, M., 2004. 'Dead wood in European forest reserves - a reference for forest management'. EFI Proceedings 51: 181-191.
- Siitonen, J., 2001. 'Forest management, coarse woody debris and saproxylic organisms: Fennoscandian boreal forests as an example'. Ecological Bulletins 49: 11-41.
- MCPFE: www.mcpfe.org.
- European Forest Insititute: www.efi.int.
Indicator specification and metadata
Volume of standing and lying deadwood in forest and other wooded land, classified by forest type (Ministerial Conference on the Protection of Forests in Europe (MCPFE) (MCPFE) definition). In national forest inventories, countries generally classify according to type (standing, snags, lying, species and state of decay).
No units have been specified
Policy context and targets
Deadwood (coarse woody debris) in form of snags (dead standing trees) and logs (dead lying trees) is a habitat for a wide array of organisms and after humification an important component of forest soil. Some species are dependent, during some part of their life cycle, to find a place to live, either on the surface or in cavities/protected places of dead or dying wood of moribund or dead trees (standing and fallen), or upon wood-inhabiting fungi or other species. Because of lack of deadwood in multipurpose forests many of the species dependent on deadwood are endangered.
At present it is still debated what amount of deadwood is required in order to maintain the most valuable species and under what circumstances the accumulated deadwood component may give rise to a risk for insect outbreaks.
Relation of the indicator to the focal area
Decaying wood habitats are important components of biodiversity in European forests and recognised as an indicator for assessing and monitoring biodiversity as well as sustainable forest management.
No targets have been specified
Related policy documents
No related policy documents have been specified
Methodology for indicator calculation
Definition of terms:
Terminology is well defined for international reporting by MCPFE. Dead wood (coarse woody debris) as such as well as the methodology for reporting of volume are thus defined by MCPFE.
On a national scale monitoring of deadwood is carried out in several National forest Inventories (NFIs). Work towards harmonisation of terminology is carried out by the COST E43 action. This comprises type classification (standing, bending, lying) as well as potentially important additional parameter (Uprooted stems, Clearcut stems, Pieces of stems, Cut branches, Uprooted staves, Logging residues, Fine woody debris, Intact snags, Broken snags, Broken, lying stems without uprooting). There are several approaches to register state of decay, most commonly this is classified in 5 classes. Noting the tree species is desirable but data are not collected by everybody.
MCPFE has defined the following reporting of the indicator "Deadwood":
- Status: m3/ha.
- Changes: m3/ha/yr.
Figures to be reported on
- Volume of dead standing trees (snags) and lying trees (logs) on forest area and
other wooded land, classified by forest type.
Minimum length and diameter of standing and lying dead trees
- Length: 2 m.
- Diameter: It is up to the countries to define the minimum size of diameter to be
reported. It is recommended that the minimum size be:
Standing deadwood: 10 cm d.b.h.
Lying deadwood: 10 cm mean diameter.
A European Forest Types classification has been proposed to MCPFE (EEA, 2006).
Methodology for gap filling
No methodology for gap filling has been specified. Probably this info has been added together with indicator calculation.
No methodology references available.
No uncertainty has been specified
Data sets uncertainty
No uncertainty has been specified
MAIN DISADVANTAGES OF THE INDICATOR
- The indicator is a general measure on habitat quality. It will not, at least not in international reporting, be possible to evaluate the indicator with respect to specific organisms, e.g. threatened species.
- A minimum level of required deadwood to create suitable habitats in multifunctional forests is not yet defined. This will probably have to be done when developing management plans at landscape or stand scales. Huge amounts of deadwood may also be a risk (insect calamities, fire).
- Methodology to measure deadwood differs between countries. Some countries include also tree stumps into the calculations. Numbers may also be influenced by the share of undisturbed forest (in which case figures for deadwood may reflect the share of undisturbed forest instead of the real amount of dead wood in production forests).
ANALYSIS OF OPTIONS
The 35 MCPFE quantitative indicators (http://www.mcpfe.org/documents/r_2007/ici)
all relate to sustainable forestry management. From this set, those with most direct relevance to biodiversity were selected.
Biomass stock in forest and other wooded land (Forest Resources Assessment 2005 - country tables)
provided by Food and Agriculture Organization of the United Nations (FAO)
Biodiversity (Primary topic)
- SEBI 018
Contacts and ownership
EEA Contact InfoKatarzyna Biala
EEA Management Plan2010 (note: EEA internal system)
For references, please go to www.eea.europa.eu/soer or scan the QR code.
This briefing is part of the EEA's report The European Environment - State and Outlook 2015. The EEA is an official agency of the EU, tasked with providing information on Europe’s environment.
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