Neutral modelling of agricultural landscapes by tessellation methods-Application for gene flow simulation

Neutral landscape models are not frequently used in the agronomical domain, whereas they would be very useful for studying given agro-ecological or physical processes. Contrary to ecological neutral landscape models, agricultural models have to represent and manage geometrical patches and thus should rely on tessellation methods. We present a three steps approach that aimed at simulating such landscapes. Firstly, we characterized the geometry of three real field patterns; secondly, we generated simulated field patterns with two tessellation methods attempting to control the value of some of the observed characteristics and, thirdly, we evaluated the simulated field patterns. For this evaluation, we considered that good simulated field patterns should capture characteristics of real landscapes that are important for the targeted agro-ecological process. Real landscapes and landscapes simulated using either a Voronoi or a rectangular tessellation were thus compared when used as input data within a gene flow model. The results showed that neither tessellation method captured field shapes correctly, thus leading to over or (small) under estimation of gene flow. The UMR 7517 LHyGeS & UMR 7503 LORIA, ENGEES, F-67000 Strasbourg, [email protected] UR 1115 PSH, INRA, F-84000 Avignon Unité MIA, INRA, F-78350 Jouy-en-Josas UAR 1240 Eco-innov, INRA, F-78850 Thiverval Grignon UMR 1210 BGA, INRA, F-21000 Dijon UMR 7503 LORIA, U. Nancy 2, F-54506 Vandœuvre-lès-Nancy Unité MIA, INRA, F-78350 Jouy-en-Josas