Can fire avoid massive and rapid habitat change in Italian heathlands

Abstract Heathlands are a peculiar habitat of western Europe, and have markedly declined over the last decades. Most of the remaining fragments are now protected, but are still threatened by the encroachment of pioneer trees such as Betula pendula Roth and Populus tremula L. Prescribed fire and mechanical cutting are commonly used to control pioneer trees in northern countries, but there is little understanding of their effects towards the southern edge of the range of European heathlands. I report the results of 14 years of monitoring in a network of permanent plots located in the Vauda, one of the largest lowland heathlands in Italy. Even at high frequencies (≥3 burns in 14 years) fire did not control the expansion of pioneer trees. Actually, at frequencies of 1–2 burns in 14 years, fire stimulated the expansion of pioneer trees. The growth of pioneer trees was rapid: grassland might be completely lost from the Vauda Nature Reserve in as little as 15 years. Only yearly mechanical cutting was able to control woody plants, while in mown plots cover of C. vulgaris ranged between 7% and 19% through the study. This work shows that management of southern European lowland heathlands must be more intensive than what is usually applied in north-European contexts, because fire alone cannot control pioneer trees. Rather, combinations of prescribed fire, mowing and increasing grazing/browsing will be necessary to achieve long term conservation of heathlands where fast rates of scrub and woodland encroachment is observed.