How grazing and other disturbance factors influence biodiversity in Cyprus, with a focus on breeding bird communities

Abstract

AbstractGrazing and browsing by sheep and goats has been an important anthropogenic influence on ecosystems in the Mediterranean region for centuries. This influence has changed significantly in recent decades, with a general shift from free-range grazing to the penning of animals. The intermediate disturbance hypothesis (IDH) proposes that perturbation - including anthropogenic disturbance - is the “norm” for ecosystems, and Mediterranean systems in particular, and that higher species diversity is found under conditions of continuous, low-level perturbation. We used Cyprus as a case study with the aim of assessing the impact of changes in grazing practice on biodiversity, while also taking account of other anthropogenic factors, such as fire. We aimed to test the IDH as it relates to grazing of scrub and open forest habitats in Cyprus, in the context of the general shift away from free-range grazing. Our hypothesis was that a greater diversity of breeding birds and plants would be found at sites subject to continuous low-level grazing perturbation over a long period of time, compared to sites where grazing has recently ceased, overgrazed sites and sites that have never been grazed.We carried out surveys of breeding birds and vegetation at 48 study sites in scrub and open woodland across Cyprus. We estimated relative grazing pressure (past and present) and fire history at these sites, and looked for associations between these factors and birds, and perennial vegetation.Our findings showed the importance of anthropogenic disturbance for biodiversity in scrub and open forest habitats in Cyprus. However, our results relating to the influence of fire and grazing on birds and vegetation suggest that it is not a regime of continuous low-level disturbance, but rather the absence of perturbation – or at least only very low-level perturbation – that benefits biodiversity in these habitats in Cyprus. This suggests the best approach for biodiversity management in scrub and open woodland habitats in Cyprus is to keep grazing to a minimum and avoid fires, though a ‘no grazing’ approach should also be avoided, because absence of grazers would likely increase fire risk.