Further use of hemiparasitic plants to increase species diversity

This post is the next in a series on the use of lousewort (Pedicularis lanceolata) a hemiparasitic plant common in wetlands, to increase species diversity. At the edge of our wetland the sedge Carex trichocarpa was forming very dense monospecific stands. Because of the sedge, no other species were able to get established.

In 2009 I discovered that lousewort was starting to move into these Carex stands. Lousewort is known to parasitize sedges. The hope was that this action would open up the site so that other species could become established. Therefore we collected lots of lousewort seeds and planted them in the large Carex patches.

By 2011 the lousewort was beginning to have its effect. The Carex had been knocked  back and other species were beginning to be established.

Over the next two years we continued to plant lousewort seeds in more Carex areas, with good effect. This spring all these Carex areas were  burned as part of our major wetland burn. By now the Carex has almost disappeared (see photo below) and a wide variety of wet mesic prairie species have become established. Species here include Baptisia alba, Pycnanthemum virginianum, Silphium perfoliatum, Rudbeckia hirta, R. laciniata, and Veronicastrum virginicum.

We have lots of lousewort growing at the edge of our wetland, and the seeds are easy to collect and plant. Thus, it is quite easy to use this technique to increase species diversity.