Assessing Forest Classification in a Landscape-Level Framework: An Example from Central European Forests

Experience of Forest Ecological Classification in Assessment of Vegetation Dynamics

Due to global climate change and increased forest transformation by humans, accounting for the dynamics of forest ecosystems is becoming a central problem in forestry. We reviewed the success of considering vegetation dynamics in the most influential ecological forest classifications in Russia, the European Union, and North America. Out of the variety of approaches to forest classification, only those that are widely used in forestry and forest inventory were selected. It was found that the system of diagnostic signs developed by genetic forest typology based on the time-stable characteristics of habitats as well as the developed concept of dynamic series of cenosis formation allows us to successfully take into account the dynamics of vegetation. While forest dynamics in European classifications is assessed at a theoretical level, it is also possible to assess forest dynamics in practice due to information obtained from EUNIS habitat classification. In ecological classifications in North America, the problem of vegetation dynamics is most fully solved with ecological site description (ESD), which includes potential vegetation and disturbance factors in the classification features. In habitat type classification (HTC) and biogeoclimatic ecosystem classification (BEC), vegetation dynamics is accounted based on testing the diagnostic species and other signs of potential vegetation for resistance to natural and anthropogenic disturbances. Understanding of vegetation–environment associations is fundamental in forming proper forest management methods and improving existing classification structures. We believe that this topic is relevant as part of the ongoing search for new solutions within all significant forest ecological classifications.

Intensive site preparation for reforestation wastes multi-trophic biodiversity potential in commercial oak woodlands

Lowland oak forests host high biodiversity throughout Europe, and to maintain their high biodiversity potential we need to understand how current silviculture practices influence these ecosystems. The most common harvest approach in oak woodlands remains clear-cutting followed by site preparation for reforestation. The site preparation can vary in intensity and possibly affect forest biodiversity in various ways. We studied the impact of site preparation intensity on ground-dwelling arthropod predators and detritivores in commercial oak woodlands. The intensive management included mechanical site preparation with soil milling, stump removal, and herbicide application. The extensive management consisted of natural succession after reforestation with only such slight disturbances as regular hand-provided mowing of vegetation. We recorded 120 spider species, 92 species of ground beetles, 10 species of centipedes, 17 species of millipedes, and 7 species of woodlice, including a relatively large number of threatened species. We found that intensive post-logging management strongly homogenized the habitat structure, and this led to low multi-trophic taxonomic and functional diversity in comparison to that under extensive management. At sites with extensive management, there was not only high functional diversity but also high functional redundancy. Species of conservation concern almost vanished from clearings under intensive management. The high multi-trophic diversity and functional redundancy indicate that extensive site preparation may enhance ecosystem multi-functionality, including primary productivity and ecosystem resilience. Extensive post-harvest management is therefore strongly preferable, and it is also economically more feasible. Intensive post-harvest management should be prohibited in lowland forests within transition zones to localities under nature protection or in natural oak forests.

Presentation of landscape-fuzzy approach of forest capability evaluation (LFAFCE) for degraded sites

Evaluation of forest sites capability (EFSC) is important for the restoration of degraded areas. The current costly EFSC approaches developed based on forest stand structure criteria is too costly for less developed countries (LDC) and not suitable for severely degraded lands. This paper describes an inexpensive Landscape-fuzzy approach for forest capability evaluation (LFAFCE) that can be used to restore degraded forest areas especially in LDC. Five physical criteria of slope, hillshade, altitude, precipitation, and geo formation were evaluated in the Zagros region of western Iran using the fuzzy membership functions, prioritized by analytic network process (ANP), and combined with GIS-based weighted linear combination. We then performed multi-criteria evaluation integrated by GIS. Given the positive correlation between the independent variable of EFSC and the dependent variable of the dominant tree height, the model results were validated based on the linear regression of the relationship between the two variables. The results of the validation showed that the linear regression model with appropriate coefficient of determination was significant. The results of EFSC by LFAFCE showed that most of the forest area was allocated to two classes: well (75%) and moderate (21.8%). In total, only 3.2% of the area belonged to the marginal (0.4%), high (0.1%), and unsuitable regions (2.7%) classes. Our results demonstrate that LFAFCE is valid for low-cost evaluation of degraded area in Zagros and for other similar areas, if calibrated, where normal forest mass parameters are not available.

Thorny Shrubs Limit the Browsing Pressure of Large Herbivores on Tree Regeneration in Temperate Lowland Forested Landscapes

Thorny shrubs are considered as an important driver in the natural development of temperate forest structures, particularly in European lowland forests. We assessed the current role of thorny shrubs in the regeneration of deciduous tree species under heavy browsing pressure in a central European temperate forested landscape. The study’s military training area offered a unique opportunity to investigate the processes in which deciduous tree seedlings grew under thorny shrubs and in the close vicinity of thorny shrubs in a landscape with a high density of large herbivores (red deer and sika deer). We assessed the number of seedlings, species composition, seedling height, and degree of browsing damage, and their relationship to study plots elevation, thorny shrub species, coverage, and height. The regenerated tree seedlings were mostly detected as common ash (Fraxinus excelsior) and wild cherry (Cerasus avium). The species of thorny shrubs were blackthorn (Prunus spinosa), hawthorn (Crataegus sp.), and wild rose (Rosa sp.). We found that the thorny shrubs protected the tree seedlings from browsers to a large extent. However, the effects of thorny shrubs on the tree seedlings' characteristics varied among the shrub species. While results revealed significant effects of hawthorn and wild rose on the tree seedlings' abundance and survival, blackthorn’s negative effect of shading the tree seedlings outweighed its protective role. These results indicated a possible mechanism that enabled the regeneration of deciduous tree species under large herbivore pressure. These results can be applied in the landscape planning and forest management of deciduous tree regeneration and forest restoration in temperate forested lowland landscapes, where high densities of large herbivores (without the presence of large predators) usually occur.

Bird Diversity as a Support Decision Tool for Sustainable Management in Temperate Forested Floodplain Landscapes

Sustainably managed forests provide multiple ecosystem services in cultural landscapes, including maintaining biodiversity. Better understanding of the benefits regarding the biodiversity of different silvicultural practices is important for sustainable landscape management. Conservation targets in forested landscapes should be determined by land managers and policy-makers, based on serious ecological research. This study deals with response of bird diversity to three different habitat types of temperate hardwood floodplain forests, which reflect specific forms of forest management. Research was based on long-term field bird census in the years 1998 to 2002 applying the point count method. Data was analysed using regression analysis with dummy variables. The results of the study indicate that hardwood floodplain forest heterogeneity, supported by different types of forest management (old-growth forest protection, group-selection harvesting and forest edge protection), provides large-scale habitat mosaic conditions suitable for many breeding bird species with different ecological niches. This result suggests that comparison of bird diversity response to different forest management types can be used as a decision support tool for sustainable landscape management strategy and local management practices in forested cultural lowland landscapes. Improvements in both regional and local ecological knowledge are generally needed in order to control floodplain land use decisions, which are typically made on the scale of landscape management.