Assessing and Monitoring the Status of Biodiversity-Related Aspects in Flemish Forests by Use of the Flemish Forest Inventory Data

Abstract

Ecological aspects are increasingly influencing silvicultural management. Estimating forest biodiversity has become one of the major tools for evaluating management strategies. A standardised and practical methodology was developed for the monitoring of some important aspects for biodiversity in forests on a stand-scale level. The scoring system was conceived in such way that it should be applicable to the forest inventory dataset for Flanders (Belgium). Only these aspects that are both easily measurable and susceptible to changes through silvicultural measures, such as stand structure and dead wood amounts, are included. Other important aspects for forest biodiversity like forest history, size and connectivity are not included. Therefore the index is not described as a ‘biodiversity index’ but as an ‘authenticity index’, as defined by Dudley (1996): ‘a reflection of the extent to which a forest corresponds to a naturally functioning forest in terms of composition and ecology’, and thus a measure for ‘potential biodiversity’. Test calculations were performed and proved the index to be sensitive to changes due to management and to be reflecting the actual structural and compositional diversity of forest stands. Through automatic calculation, the index values could be produced for the complete data set of the forest inventory. This lead to authenticity values for over 1300 plots, giving a general impression of the status of some important elements for forest biodiversity in the Flemish forests. The total value of the index and the values of the subindices are discussed. The overall ‘authenticity’ value of the Flemish forests is low and confirms certain general shortcomings of the forests towards biodiversity. Nevertheless, for almost every indicator a maximum value could be reached for at least one plot, indicating that the index is not too strict. Further preliminary analysis of relationships of the index with forest history, soil texture type and type of ownership were performed. The results point out that ancient woodlands and forests on richer soils generally have slightly higher index values, while ownership seems to have no influence on the index. The authenticity index proves to be a powerful and practical tool for evaluation and monitoring of the future development of the Flemish forest as far as important aspects for biodiversity are involved, through its direct link to the forest inventory.KeywordsForest StructureDead WoodHerbal LayerPrivate ForestForest BiodiversityThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.