Continuous Cover Forestry
In this section
- Timber as the forest interest
- Benefits and constraints
- CCF in Ireland
- Transformation to CCF
- CCF shelterwood system
- CCF selection system
- CCF case studies
Continuous Cover Forestry (CCF) is a forest management approach suitable to both conifers and broadleaves. It allows for the production of commercial timber while retaining a forest cover at all times. It often relies on harnessing natural forest processes such as natural regeneration of trees, mixed species, increased biodiversity and natural forest development (forest succession). For this reason, it is also known as Close-to-Nature forest management.
CCF encompasses a number of silvicultural systems each suited to different circumstances. CCF systems can be divided in two broad categories:
Stand stability is an important factor in considering transforming to CCF systems. It is not an option for all sites as issues with elevation and soil quality might undermine forest wind stability during the transformation process. Sheltered sites with free draining soils are most suited. High deer density sites would also be difficult to transform to CCF due to browsing of young trees if adequate deer management is not in place.
CCF systems, on suitable sites, offer a possible alternative to the widely practiced clearfell / replant system where trees are harvested all at once at the end of the rotation. This is then followed by one replanting operation.
Higher structural diversity and species diversity allow CCF systems to integrate timber production with a high level of ecosystem services. These services include soil protection, long term and stable carbon storage, water protection, landscape, recreation and habitat refuge for a wide range of woodland species of flora, fauna and fungi. Such services are increasingly valued by society.
Under CCF management, the timber is -in essence- viewed as the interest generated by the growing forest capital. In many respects, managing a forest for timber under CCF can be compared to the process of rearing a herd for beef production. To the suckler beef system, the suckler cows are the capital and the calves are the interest:
|Capital||Selected breeding herd animals||Selected high quality standing trees providing seed|
|Herd genetics, quality and productivity improves||Forest genetics, quality and productivity improves|
|Interest||Live weight of beef sold||Timber sold|
Compared to the current clearfell / replant system where all trees are harvested / replanted once at the end of the rotation, CCF offers the possibility to harvest a similar timber volume over the same period of time but in regular instalments (3-6 years) and without any loss of forest cover. This has a range of potential benefits but also some constraints.
- Regular income and forest capital value increase
- Higher quality timber potential / greater proportion of sawlog from each harvest
- Market flexibility / greater timber assortment
- Sustained skilled rural employment potential
- No large scale / open field replanting
- Increased pest protection
- Soil and water protection
- Permanent deep rooted forests intercept, slow and retain large amounts of water due to deeper soil percolation
- Enhancement of forest biodiversity by maintaining forest condition
- Wildlife and landscape enhancement
- Climate change resilience / long term carbon store
- Opportunities for alternative forest uses (e.g.: eco-tourism, game shooting, wild edible mushrooms)
- No large timber sale / payment at any one time
- Regular monitoring required
- Possible higher level of road density / maintenance required
- The greater species range and larger dimensions of timber (>50cm Diameter at Breast Height or dbh) typical of CCF might be more difficult to sell to current Irish sawmills. They are currently predominantly set up for one species (Sitka spruce) of smaller uniform dimensions (generally <40cm dbh).
CCF is relatively new to Ireland but has been practised widely throughout Europe for many years. In recent years, Coillte and a growing number of private forest owners across Ireland are initiating transformation to CCF. In addition, a number of CCF monitoring sites have been established. This will provide useful insights on best practice for this forest management approach under Irish conditions.
Pro Silva Ireland (external link) promotes CCF management through open days, forest site visits, discussions and information dissemination.