Habitat management against alien trees in the habitat of strictly protected plants

Abstract

Habitat management in order to force back alien species was carried out in the habitat of 2 strictly protected plant species, namely Onosma tomense and Iris aphylla subsp. hungarica,within the operational area of the Aggtelek National Park Directorate. In the habitat of Iris aphylla Robinia pseudo-acacia was spreading, while in the habitat of Onosma tomense Ailanthus altissima has been occupying open areas. In both cases glyphosate herbicide (Medalion) was used. Before the management was carried out, experiments had been conducted to find the most effective and environment-friendly method. In the habitat of Iris aphylla subsp. hungarica against the spreading of robinia, 20% of glyphosate herbicide concentration was used to treat the cut stumps and the foliage. More than 90% success was achieved. Elimination of Ailanthus requires diligence, due to its copious seed production, high seed germination rate, and vegetative reproduction. Cutting is counter-productive because Ailanthus responds by producing large number of stump sprouts and root suckers. Following the experiments two methods seemed to be the most effective for Ailanthus control; herbicide application on the foliage and hack-and squirt method, applying concentration of 15% of a glyphosate herbicide (Medalion) during late summer. Application to the foliage resulted in 100% success, while hack-and squirt method achieved 86% success. The second technique can be used when the tree is too high to treat its leaves. Furthermore, it is more friendly to the environment, which accounts for its application in protected areas. Follow-up monitoring and treatment when needed should be an integral part of the habitat management program.