Forest functions and their categories
In relation to human society forests fulfil various functions. These functions are in different countries defined otherwise yet we can say there are 3 main functions (or their groups) more or less uniform for all countries. They are:
Production function that is to say production of marketable goods,
Protective function which means implementing of forest stand abilities to protect other components of the environment (chiefly soil), and
Various special functions
Forest stand must be managed in a certain way to secure the fulfilment of the function required. For some functions it is better to leave forest stand unmanaged yet this is a very rare policy in Central Europe in general. Forest stand management adequate to their functions is guaranteed by division of forest stands into several categories and subcategories. There are 3 main forest categories in Slovakia:
- Commercial Forests
- Protective Forests
- Special purpose Forests
Every single stand fulfils several functions, both productive and non-productive. Forest stand categorisation is therefore based on its dominant function.
Forest functions in general are not based only on subjective human demands, they are significantly and objectively limited by site conditions of individual forest stands. For this reason, forest categorisation is narrowly linked to site typification and categorisation of every forest stand into production forest or protective forest category respectively is based on the dominant site type present. Category of special purpose forests represents a certain exception to this rule and these forests are designated on the basis of either their social or certain group importance. However, certain limitations related to the site character still remain, as protective function is paramount to any other.
This category includes forest stands primarily with timber production function. Theoretically we could also think about other forest products such as resin, cork, animal fodder produced by understorey, etc, but these non-timber commodities carry very little importance in the context of Slovakia and law directly prohibits yielding some of them.
Apart from production function commercial forests usually also fulfil further functions. However, their importance should not exceed the significance of their main function. Purely commercial forests are in the context of Slovakia very rare. In the future we can expect even growing importance of non-productive forest functions.
Category of commercial forests is almost exclusively delimited by the site typification units that is to say by forest site types. Suitable forest stands are without any special approval and designating procedure automatically included in it.
Commercial forests are managed on the basis of common forestry practices, only restrictions given by the currently standing forest act are implied. Individual forest stands are managed in compliance with approved forest management plans, which are based on management models approved by state administration bodies. These models contain parameters of basic framework planning including rotation period, regeneration period, silvicultural system, etc and management objectives such as targeted tree species composition, targeted stand structure and targeted commodity.
Within this category, even-aged forest stands managed by the shelterwood system are absolutely prevalent on the whole territory of Slovakia. In well-documented and justified cases also clearcutting system is acceptable yet possible negative impacts on non-productive forest functions (mainly soil anti-erosion one) must be carefully assessed beforehand. Selective silvicultural system is also applicable in these forest stands but due to present age structure of Slovak forest stands we can not seriously expect its increase.
In lower altitudinal vegetation zones (1st to 3rd) we record a high proportion of coppice stands and forest stands of low quality formed by black locust and hornbeam. These stands do not use site production potential to the full and even from the point of view of nature conservation are of lower quality when compared to natural ones. Their conversions are because of their biological properties very complicated. In higher altitudinal vegetation zones there is very often recorded a high, site inadequate proportion of spruce at the expense of other, more stable tree species.
Main function of forests falling into this category is to protect soil (both under forest stands as well as outside stands in case of windbreaks), riverbanks and lower altitude hillside forest stands.
In the past there was a long-standing tendency to leave these stands intervention free. From the state conservation bodies' point of view the attitude still remains pretty much the same and these forest stands are unofficially considered nature reserves. However, it has been proven that these forests need to be managed because of unfavourable changes to the environment and quite often their inadequate structure and tree species composition inherited from the past.
The main objective of management in these forests is never the production side, although it is not sometimes negligible, but assurance of their continual protective function. This requirement can be met only via sustainable existence of forest stands without even the hypothetical short temporary clearcut of larger intact areas.
Protective forests are designated, re-categorised or excluded completely from the category on the basis of Lesoprojekt site type survey only by authorised state administration body. They are divided into the following categories:
Forests on extreme sites - their chief function is to protect soil against erosion, less often also against wetting. This sub-category includes forest stands on naturally extreme sites such as scree, rocky mountain ridges and ravines, hillsides with shallow soils and continually emerging bedrock, soft alluvia, peat bogs and other boggy soils.
Mountain forests beneath the upper tree line - their main function is to protect lower altitude forest stands and land against avalanches. Further on they very often serve as soil protection on steep and rocky locations. This sub-category mostly includes forest stands of the 7th vegetation zone (spruce), yet also forest stands of lower vegetation zones can belong here if site conditions are somehow extreme such as some minor side mountain ridges or locations with the 7th zone being deforested.
Forests located in a dwarf pine zone - their main function is equal to the previous category. This sub-category exclusively contains only forest stands of the 8th vegetation zone (dwarf pine).
Other forests with prevalent soil protection function - their chief function is to protect soil against erosion, in exceptional cases also against wetting. Under current legislation, this category is not entirely clearly defined. It includes forest stands on naturally extreme sites (mostly on steep rocky mountain sides, less often also sites with shallow or waterlogged soils), as well as forests stands on secondary degraded sites (erosion gullies, landslides, areas destabilized by mining industry) and forest stands serving as protection to their adjacent areas (windbreaks) or riverbanks. The ideal silvicultural system for such stands is selective, yet thanks to a great variability of forest stands included, there are also other management systems being applied.
This category includes forest stands securing special public-beneficial functions given by specific social needs. These needs are also reflected in the selection of the most suitable management system. It is necessary to realise that these forests meet also to a various extent other functions apart from their main one. However, their main function remains dominant and paramount to all the others. Some functions, when considered highly important, even mutually exclude themselves such as, for example, a combination of recreational and water protection or game management ones.
This category of forests is not defined by specific site type units (units of a protection character are not applicable, though), the level of importance of a certain function is exclusively given by social demands only. Therefore, their declaration is virtually in the hands of forestry state administration bodies while initiative comes from owners, users or other state administration bodies. Lesoprojekt is only responsible for submitting proposals for air pollution damaged special-purpose forests.
Category of special-purpose forests is further divided into the following subcategories:
Forest stands in buffer zones of reservoirs: Their main function is to guarantee adequate water quality of reservoirs. This function is in many countries regarded as a protection function rather than the special one. These forest stands are almost solely being located in reservoirs' vicinity, the strictest first protection zone is usually excluded from the forest fund.
So called "Spa forests" represent a fairly controversial subcategory as they fulfil 2 mutually opposite functions - mineral and healing spring protection (this function is basically identical with the water protection one) and recreational one. Even if both functions' interest areas overlap, the management measures applied are very often right opposite. These forests are generally located in close vicinity of spas.
Recreational forests serve for public recreation: This function can be understood in very broad terms, however, current forestry legislation slightly underestimates it to say the least. Strictly taken, this subcategory nowadays includes only inner zones of residential recreational forests. In reality all municipal forests and forests around recreational zones including areas around footpaths and roads importantly fulfil this function.
Forests in game reserves and pheasant enclosures ensure game management interests that is to say secure the production of non-wood commodities such as game, specific services such as hunting or adaptation of introduced game species. This subcategory includes forest stands of already designated game reserves and pheasant enclosures or their parts respectively. We have to say that this function is being fulfilled to a certain extent by the majority of Slovak forests yet apart from the above-mentioned special facilities it is never paramount to the other functions.
Forests important for nature conservation: Their main function lies in nature protection. Their main objective is to preserve selected ecosystems for scientific purposes and to ensure the stability of ecosystems in a broader context. This subcategory includes forest stands of small-scale protected areas (nature reserves, natural monuments, etc) as well as parts of large-scale protected areas (NP and landscape protected areas). These forest stands as given by the nature protection act fall into several nature protection levels (usually stricter ones) and thus legal management restrictions are likewise different.
Parts of forests damaged by air pollution under current understanding do not fulfil any special function. So called "anti-pollution" function commonly being mentioned in relation to these forests basically means the protection of urban areas against pollution via green buffer zones. These are in the context of Slovakia put only into a limited use and are not commonly being designated as special-purpose forests. Under current practice, this subcategory actually groups vast areas of forests to a various degree damaged by air pollution, mainly remote transfer one. The fact that these forests are being damaged by air pollutants is adequate enough reason to manage them in a special way, yet we can not call this fact their function. The true reason behind such practice is that once these forests having been designated as special-purpose ones, there is legal basis for the compensation of both their owners and users alike.
Forests serving for educational purpose and research: These forest stands represent a kind of model forests aimed at testing, verification and practical illustration of various management systems (wrong ones including).