Vegetation succession and soil gradients on inland sand dunes

A part of the sand dune area with the best-preserved pioneer sand vegetation in the vicinity of the town of Durdevac in northern Croatia was declared a Botanical Reservation in 1963. Since then natural succession and other vegetation types replaced the pioneer sand vegetation. Vegetation succession was studied using the space-for-time substitution approach. The environmental features related to the succession process were also studied. The co-structure among the succession stages and some soil features were established by constrained ordination (Co-Inertia Analysis). Organic matter and nitrogen contents showed the strongest relation with the vegetation structure. These two soil properties are assumed to be the most important driving forces for vegetation succession on sand. Therefore, all measures for slowing down or halting vegetation succession with the aim of conservation or recovering the pioneer sand vegetation need to be focused on reducing the organic matter and nitrogen in the soil.