Aboveground persistence of vascular plants in relationship to the levels of airborne nutrient deposition

This paper examines whether high atmospheric nitrogen deposition affects aboveground persistence of vascular plants. We combined information on local aboveground persistence of vascular plants in 245 permanent plots in the Netherlands with estimated level of nitrogen deposition at the time of recording. Aboveground persistence of vascular plants was studied using two types of survival statistic technique: Kaplan–Meier analysis and Cox’ regression. We expected a link between nitrogen deposition and loss of plant species due to intensified herbivory or other forms of tissue loss that would lead to diminishing local aboveground persistence. This could not be detected. In contrast, a positive relation was found between local aboveground persistence of plants and high levels of ammonia deposition. This result is considered to be an indication of lower colonization access, for example due to limited space (e.g. the chance of successful establishment of individuals from new species is lower). The results are discussed in relation to the extremely high levels of nitrogen deposition in the studied plots. This study provides an indication that management practices aiming for restoration of colonization access (e.g. mowing, grazing and sod cutting) are vital under heavily eutrophied conditions