Impact of one year crozier removal on long-term frond production in Matteuccia struthiopteris

Abstract

Matteuccia struthiopteris (L.) Todaro populations that had been subjected to crozier harvesting over the past 25 yr were investigated. The number of crowns harvested and the number of croziers harvested per crown varied annually, but most crowns were harvested at least once over 5 yr. In 1995, total and 50% defoliation impacts were tested on subsequent years’ frond production in understorey and open site populations. The effect of mineral fertilization on the understorey population was also investigated. Crowns in the open habitat produced more fronds annually than the understorey crowns and were less susceptible to partial defoliation. One year with total defoliation was sufficient to significantly reduce the number of fronds produced in both habitats over the next 4 yr. Defoliated crowns also accumulated less carbohydrates at the end of the first season. Mineral fertilization increased the number of fronds produced the following year but had no long-term benefit and did not significantly alleviate defoliation effects. Despite the fact that harvesting intensity was relatively low, it appears necessary to limit crozier harvesting per crown to less than 50% in understorey populations to preserve wild populations of M. struthiopteris. Key words: Defoliation, carbohydrate reserves, fertilization, fiddlehead, Matteuccia struthiopteris