Control method that may limit an invasive plant in a protected area: Stem breaking decreases alien goldenrod performance and enhances pest attack

Abstract

Developing alternative control approaches is particularly important for reducing the impact of biological invasions in protected areas. We present a simple stem-breaking control approach for alien goldenrod, Solidago gigantea. The method was tested at the Natura 2000 site ‘Skawina meadows area’ in southern Poland, where S. gigantea threatens the co-occurring protected and rare native species. The tests were performed over 40 days in 2012 and 2013 and involved hand-breaking of stems. Control and broken plants were surveyed in terms of their performance and pest pressure, and the number of pests attacking a given control and/or broken plant was assessed. We found that stem breaking may reduce S. gigantea generative reproduction potential by preventing seed release and increasing pest pressure. The dominant pest groups were Stylommatophora and Auchenorrhyncha. Application of this method in strictly protected areas does not require virtually any equipment and can be performed by non-qualified volunteers. Thus, the proposed approach may be an economic and environmentally friendly method of alien plant species control; however, further tests at a larger scale are needed to confirm this hypothesis.