Utilization of multifrequency permittivity measurements in addition to biomass monitoring

Abstract

The ecosystemic approach to landscape is based on a number of principles developed by or applied in landscape ecology. The principles useful to the elaboration of ecological networks are presented here in the form of summary recapitulations so as to facilitate understanding of how this new, more complex method — yet one firmly founded on recognized scientific principles — is set up. The principles underlying the ecological networks approach have already been described in the final report of the Swiss national Ecological Network project (Berthoud & al, 2004). Prior to that, the account of a partial practical application of the method was published in the context of the departmental ecological network of the Isère (ECONAT, 2001). An account of a complete practical application of the “hierarchically organized ecological networks” method has never yet been published, but already exists in the form of technical charts drawn up for various partial applications. The ECONNECT Project constitutes an opportunity to present the method as it was applied in its entirety and progressively calibrated over a period of ten years in projects focused on the French department of the Isère. The approach was structured over two distinct stages: - The cartography of the natural infrastructure of the landscape; - The exploitation of available eco-geographical data according to a tri-factorial evaluation system weighted according to multiple criteria. The analysis of landscape structure is based on the existence of a spatio-temporal entity termed a “continuum”. A continuum defines a living space that is available in a landscape for a group of species sharing analogous ecological affinities. The variable frequentation of this theoretical living space is defined in terms of a graduated scale of frequentation intensity. And this scale allows us to establish a differentiated standard zoning:
A nodal or reservoir zone = Constant presence of populations;
An extension zone = Regular frequent presence of populations;
A continuum margin zone = Regular periodic presence of populations;
Corridors = Episodic presence of populations. The specific characteristics of each of these different zones are also related to different qualitative and functional criteria. This model of ecological spatialization can be applied to a species guild, to a group of specialized species or to a single species according to the requirements of the analysis in question. A landscape territory always plays host to several characteristic species guilds. As a result, these necessarily occupy a number of favourable habitat continua. The aim of the hierarchically organized ecological network approach is to acquire a synthesizing picture of the living spaces required for the development of specific chosen populations. The choice of the pertinent cartographical scale results from a satisfactory compromise between the amount of necessary information about living spaces that needs to be collected and the level of scale that is useful to the problems of planning in the territory under analysis. More often than not, the choice made is relevant to a relatively limited area, an area that allows the use of a mapping scale of 1/25,000. If the object were the entire Alpine region, however, the appropriate mapping scale would be 1/100,000, so as to obtain, for example, a synthesizing cartography to a scale of 1/300,000. The analysis of the Pays Bièvre-Valloire region has been chosen to illustrate the complete methodology of the approach when applied at a scale of 1/25,000. Some of the examples described illustrate particular applications, such as the maintenance of the permeability of motorway networks to fauna or the restoration of biological corridors in highly urbanized zones. Finally an application at the communal scale describes the potential to better understand ecosystemic functioning at that scale. It is notably marked by the switch to a 1/5,000mapping scale.