Geographical and genetic distances among zooplankton populations in a set of interconnected ponds: a plea for using GIS modelling of the effective geographical distance

Abstract

In systems of interconnected ponds or lakes, the dispersal of zooplankton may be mediated by the active population component, with rivulets and overflows functioning as dispersal pathways. Using a landscape-based approach, we modelled the effective geographical distance among a set of interconnected ponds (De Maten, Genk, Belgium) in a Geographic Information System (GIS) environment. The first model (the Landscape Model; LM) corrects for the presence of direct connections among ponds and was based on the existing landscape structure (i.e. network of connecting elements among ponds, travelling distance and direction of the current). A second model (the Flow Rate Model; FRM) also incorporated field data on flow rates in the connecting elements as the driving force for the passive dispersal of the active zooplankton population component. Finally, the third model (the Dispersal Rate Model; DRM) incorporated field data on zooplankton dispersal rates. An analysis of the pattern of genetic differentiation among Daphnia ambigua populations inhabiting 10 ponds in the pond complex reveals that the effective geographical distance as modelled by the flow rate and the dispersal rate model provide a better approximation of the true rates of genetic exchange among populations than mere Euclidean geographical distances or the landscape model that takes into account solely the presence of physical connections.

The power of species sorting: Local factors drive bacterial community composition over a wide range of spatial scales

“…For more detailed information on the environmental conditions in these lakes, see Cottenie et al (23,33). Information on the morphometry and water flow between the lakes is given in Michels et al (34,35). Eleven lakes of this system were sampled in August 2001.…”

Plant biodiversity of beech forests in central-northern Italy: a methodological approach for conservation purposes

“…D'altra parte, deve essere tenuto in considerazione che la moderata pendenza delle rette di regressione, nonostante le elevate distanze spaziali, può essere l'effetto di una contenuta omogenizzazione floristica, dovuta alla capacità di dispersione delle specie presenti nelle comunità studiate. E' necessario sottolineare che questi due fattori giocano un ruolo centrale nel determinare: (i) la distribuzione delle specie; (ii) il grado di successo della colonizzazione; e (iii) le dinamiche di meta-popolazione e comunità (Nekola & White 1999, Michels et al 2001. In funzione di ciò è possibile interpretare l'ordinamento in Fig.…”

A weighted difference barrier method in landscape genetics

“…From the point of view of population genetics, average gene diversity, or average heterozygosity (H) is simply the average of all hs from all loci. There are many calculations of genetic distance such as Nei's genetic distance, Cavalli-Sforza chord measure, and Reynold, Weir and Cockerham's genetic distance (Nei 1987;Fearnhead 2007;Michels et al 2001;Nei 1973). We take one of the most frequently used one, standard genetic distance D, defined by Nei (1973Nei ( , 1987.…”

“…In addition, since geographic distance and barriers are crucial considerations in many genetic barrier analyses, GIS, spatial algorithms and models are sought after as the demand for more effective integration of geographic and genetic information increases (Michels et al 2001).…”