Onderzoeksproject OA/13 (Onderzoeksactie OA)
Introduction
Destruction of natural habitats and fragmentation of the remnants, associated with changes in land use for human activities, are now widely recognised as the major driving force in the reduction of Earth’s biodiversity. Analyses of current species extinction show recurrent patterns of distribution area shrinking and collapsing. Such patterns indicate that the disappearance of populations is a prelude to species extinction and therefore delimit both the spatial scale and the level of biological organisation relevant to the practical application of conservation measures: (1) practical conservation strategies should focus on individuals and populations and (2) landscape is the appropriate spatial scale corresponding to these levels of biological organisation. Here we define the landscape as a portion of the geographic space showing homogenous geomorphology and specific climatic features
At this landscape scale two different strategies of conservation are applicable:
- Mean quality (overall) rehabilitation, via agri-environmental schemes (ESA).
- Adequat habitat networks implementation, in order to create, sustain or improve a high connectivity level (functional), in this landscape.
This is the theoritical frame of this project: “LANDECOL: on the use of Landscape Ecology for Biodiversity Management and Conservation”.
Its aim is to assess, in a theoritical way, the contribution, for the biodiversity, of the two preceding strategies. In order to meet the ecological needs of a species’ selection, optimal landscapes will be simulated and validated. Because of its theoretical value, this project will constitute a pilot study which could drive further research in management and conservation science.
Project Descripton
Objectives
Reusing collected data dealing with the survey of biodiversity in Belgium is one of the objectives of the project. Consequently, partnerships were established, involving the Observatory of Fauna, Flora and Habitats (OFFH) for Wallonia and the Research Institute for Nature and Forest (INBO) for Flanders.
The final aim of this pilot study is to provide guidelines for decisional help to people responsible for territory management. These guidelines will permit them:
- To asses the functional connectivity within the landscape, from the species perspective,
- To target priority areas where management practices are needed,
- To get more precise information about the carrying capacity of the actual landscapes, particularly in cereal production areas
Methodology
Selection of landscapes within the whole of Belgium (4 * 100 Km²) is the first step of this research project. They were selected according to their degree of forest connectivity:
- Two landscapes in highly connected areas (Famenne and Campine)
- Two landscapes in highly fragmented areas (Hesbaye and Brabant Flamand)
Species selection is the second step of this project. Species were selected according to three main parameters: (1) they are nowadays present in the studied landscapes; (2) they belong to different taxa and (3) they are found on the regional red lists. We selected bird, butterfly and amphibian (or reptile) species. Distributional data already collected by regional agencies for the survey of their local biodiversity (OFFH & INBO) was used for this purpose.
In this research project, we use the species-specific approach, i.e. every species perceives the landscape from its own perspective. Therefore in order to elaborate species-specific maps (with species-specific habitat), different life history traits (home range size, dispersal capacity, habitat needs and density) were compiled from the literature. Consequently, habitat maps are ecologically scaled: each patch integrates its own carrying capacity value.
Cartographic modelling will then be implemented in order to analyse the present species-perceived functional connectivity within each study area. The modelling will be conducted in collaboration with the University of Wageningen (Alterra) in the Netherlands (Rene JOCHEM, Rogier POUWELS and Jana VERBOOM).
From these results, we will be able to assess the status of both the patch (isolated, key, Minimum Key Patch) and the total linked [meta]population (sustainable, non sustainable). In this way we will be able to infer for every species, the habitat network available in the landscape.
If this habitat network is sustainable, different ways for improving its quality will be considered in order to generate “improved landscapes”.
If this is not the case, a preliminary management of this landscape by means of agri-environmental schemes (ESA) will be necessary. So according to the precedent results, we will be able to easily target priority areas where intervention is needed (isolated patches supporting non-sustainable [meta]population). Then, in collaboration with the GIREA-UCL (asbl), we will consider the most adequate ESA regarding the different species requirements, in order to generate “improved landscapes”.
We expect a sustainable ecological network within the two landscapes less affected by human pressure (Famenne & Campine). Indeed, enough “natural to semi-natural” habitats seem to be available to ensure species survival. On the other hand the two other landscapes, characterised by a high human pressure (intensive cereal agriculture: Hesbaye & Brabant Flamand), preliminary management will probably be necessary in the perspective of restoring a suitable ecological network for biodiversity.
Finally, a validation step of these “improved landscape” models is planned. This end result is expected to highlight the contribution of landscape improvements in managing the biodiversity with production of conservation guidelines for further studies.
