Using geomorphological variables to predict the spatial distribution of plant species in agricultural drainage networks

PLoS One. 2018 Jan 23;13(1):e0191397. doi: 10.1371/journal.pone.0191397. eCollection 2018.

Abstract

To optimize ecosystem services provided by agricultural drainage networks (ditches) in headwater catchments, we need to manage the spatial distribution of plant species living in these networks. Geomorphological variables have been shown to be important predictors of plant distribution in other ecosystems because they control the water regime, the sediment deposition rates and the sun exposure in the ditches. Whether such variables may be used to predict plant distribution in agricultural drainage networks is unknown. We collected presence and absence data for 10 herbaceous plant species in a subset of a network of drainage ditches (35 km long) within a Mediterranean agricultural catchment. We simulated their spatial distribution with GLM and Maxent model using geomorphological variables and distance to natural lands and roads. Models were validated using k-fold cross-validation. We then compared the mean Area Under the Curve (AUC) values obtained for each model and other metrics issued from the confusion matrices between observed and predicted variables. Based on the results of all metrics, the models were efficient at predicting the distribution of seven species out of ten, confirming the relevance of geomorphological variables and distance to natural lands and roads to explain the occurrence of plant species in this Mediterranean catchment. In particular, the importance of the landscape geomorphological variables, ie the importance of the geomorphological features encompassing a broad environment around the ditch, has been highlighted. This suggests that agro-ecological measures for managing ecosystem services provided by ditch plants should focus on the control of the hydrological and sedimentological connectivity at the catchment scale. For example, the density of the ditch network could be modified or the spatial distribution of vegetative filter strips used for sediment trapping could be optimized. In addition, the vegetative filter strips could constitute new seed bank sources for species that are affected by the distance to natural lands and roads.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agriculture / methods*
  • Ecosystem*
  • Environment
  • France
  • Geological Phenomena
  • Mediterranean Region
  • Models, Biological
  • Plants*
  • Species Specificity
  • Water

Substances

  • Water

Grants and funding

Authors are grateful to the INRA institution who partly funded the experimental work exposed in this paper within the 'Pari-Scientifique: Hydro-écologie des fossés agricoles' project (INRA-EA) to FV. This project was also funded by Agropolis Fondation under the reference ID 1605-034 through the « Investissements d’avenir » programme (Labex Agro:ANR-10-LABX-0001-01) to FV. Lastly, the project was also supported by funds from a PhD grant provided by Montpellier Supagro and the INRA institution via the EcoServ metaprogram to GR. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.