Grazing as a conservation tool in Mediterranean temporary ponds

Abstract

Mediterranean Temporary Ponds - 3170* (MTP) are seasonal freshwater habitats that are strongly dependent on rainfall and annually experience a flood/dissection cycle. Their persistence has been not only compatible but also favoured by extensive human activities. So, MTP conservation must bear in mind that this habitat results from a long human presence in the Mediterranean region. In the Portuguese Southwest Coast (PSC), ongoing MTP conservation status decay is due to several anthropogenic pressures and the abandonment of traditional land uses (e.g. grazing and superficial tilling) resulting in grass encroachment and consequent disappearance of rare/less abundant flora species, and invasion by opportunistic heliophytic plants. This context is exacerbated by the current climate change scenario. During the LIFE Charcos project (LIFE12NAT/PT/997), we promoted and simulated grazing by sheep on small plots in MTPs of the PSC protected area. In a following project on the same area we managed to scale-up the most effective conservation measures. We simulated this traditional land-use regime in 10 MTP plots to recover, among others, Heliosciadium repens (Apium repens) and Caropsis verticillato-inundata (Thorella verticillato-inundata). The soil superficial tillage allowed light into the soil surface and enhanced seed germination that were still in the soil seed bank. The methods proved to be efficient as plant species richness increased. Nevertheless, these results open new questions such as: What is the resilience associated with the results obtained? Is it sustainable to carry out regular recovery actions, either environmental or economically speaking?