Why continuous cover has wealth of benefits for all
Published 04/09/2012 | 05:00
I have written previously about the concept of continuous cover forestry (CCF), also called close-to-nature forest management, with pointers on how to convert a conventional plantation to a CCF system over time. This week I will look at some advantages of close-to-nature forest management.
Before foresters and owners alike dismiss CCF as a viable, even desirable, option, perhaps they would do well to consider the long-term global trend towards the more sustainable stewardship of all our resources.
Certification of sustainable forest management is in all likelihood here to stay. As we have seen, clearfelling is now illegal in some European countries; and across Europe the size of clearfelling coupes allowed has been decreasing.
At a theoretical 25ha, our maximum felling coupe size is one of the largest allowed in any European state -- itself rather bizarre given our small total forest cover, and small average forest size. The Forest Stewardship Council (FSC) and the Programme for the Endorsement of Forest Certification (PEFC) standards for Ireland incorporate provisions to limit the extent of clearfell as a proportion of the total woodland area, and to ensure that even-aged woodlands are restructured for a greater diversity of ages and habitats.
In addition, society is les comfortable with the scars on the landscape caused by clearfelling -- whatever about the disturbance to wildlife, even the most diehard proponents of the system are unlikely to argue that a recently clearfelled site is a tourist attraction.
But this is to view CCF as an alternative in a negative light, when in fact it has many advantages.
To look first at what some would see as a disadvantage - the level of management input typical in well established CCF sites in Europe.
Even though in many cases the forests are huge in comparison to our own, they are often sub-divided into small management units and their managers have an intimate knowledge of the growing stock, sometimes right down to individual tree level.
But management is no bad thing, provided it's focused in the right direction. No business ever suffered from good quality management and attention to detail. Once the conversion to CCF has been achieved, the financial benefits can be significant.
Rather than concentrating the bulk of the returns at the end of the rotation, followed by the considerable expense of replanting and then no income at all for 15-25 years, CCF provides the owner with a regular income in perpetuity, and, it is argued, much lower costs.
The system concentrates on removing the best, largest and most valuable trees. The smaller trees are left to grow on, and only the increment is removed as income, so the forest "capital" is retained. As the species mix becomes more diverse, it opens up greater marketing opportunities.
Permanent forests are healthier and trees perform better in a CCF system. They benefit from the microclimate which is created by the permanent forest conditions, and the understorey helps to maintain moisture levels and a constant temperature within the stand.
They are also rather more stable, a particularly important consideration in Ireland where the risk of catastrophic windblow in our conventional plantations remains high.
European experience has shown that continuous cropping of spruces can result in a deterioration of stand quality over time. While it is true that the second rotation, especially, will usually be of a higher yield class than the first, subsequent rotations have proven to be less robust and productive.
One explanation is that this is due to the shallow rooting system typical of spruces -- constant swinging in the wind results in increased soil compaction, reducing aeration and therefore leading to still shallower rooting.
On this evidence, at least, it would appear the long-term viability of a clearfell system may be in doubt.
Finally, continuous cover forests are by definition more environmentally sustainable, and are more pleasant places to spend time in. For further information, those interested should contact Pro Silva Ireland at prosilvaireland.wordpress.com.
William Merivale is secretary of PEFC Ireland and a forestry consultant based in Cork. Email: firstname.lastname@example.org