Hydrochory in agricultural landscapes

Maintaining biodiversity of spontaneous species in agricultural landscapes is a major challenge regarding the bundle of ecosystem services provided by them, such as preservation of water and soil resources. It is possible to increase landscape’s resilience to climate change through their renaturalization with agroecological measures, especially maintenance practices of vegetation cover in agroecological infrastructures. 

In the Mediterranean environment, those infrastructures such as ditches, plot borders or even inter-rows of perennial crops concentrate both biodiversity and flow of matter (water, pollutants, particles), making these landscape elements particularly susceptible to intense rainfall events that contribute to exchange of biodiversity across landscapes. Managing vegetation of these elements is a significant lever for biodiversity maintenance considering impacts of plants on flows of matters, such as water and seeds. Promoting exchanges requires knowledge of the relative importance of the main types of plant dispersal i.e. hydrochory, anemochory and zoochory that affects seed exchange between landscape elements, by making the hypothesis that the hydrochoric dispersion, i.e. by water, is particularly important in the Mediterranean environment. 

To establish the potential of hydrochory to rehabilitate Mediterranean vineyard environments, we proposed a conceptual model of seed exchanges at landscape scale incorporating the levers available to stakeholders (vegetation maintenance in inter-rows, drainage ditches and plot borders), as well as climatic variables and the specific characteristics of each seed present. We will present the first results of seed dispersal experiments after a rainy event on a vineyard plot, as well as manipulations to determine the seed bank, allow us to make a first estimate of seed transport and the rehabilitation potential of Mediterranean vineyard environments. At the end of the experiments, the knowledge obtained will be integrated into a spatially explicit model based on the source-sink principle to simulate the dispersion of seeds by water, this model being considered as a virtual laboratory to co-construct landscape arrangements with stakeholders for maintaining biodiversity.