Category: Ecological Research
Title: Lack of Native Propagules in a Pennsylvania, USA, Limestone Prairie Seed Bank: Futile Hopes for a Role in Ecological Restoration
Author: * Laughlin, D.C.
Subject: Grasses, Ecological Restoration, Seed bank, Mixed-grass prairie, Invasive
Abstract: The highly threatened limestone prairies of Pennsylvania, USA, will be lost from the landscape entirely unless they are soon protected and restored . Several studies have demonstrated that seed banks can be useful in the restoration of native plant communities. Jfnative prairie propagules are still present in the soil of an early successional forest, which was once prairie according to aerial photographs from 1949 and 1971, then it may be possible to remove the invading woody plants and utilize the seed bank for limestone prairie seedling recruitment. The soil seed bank ofa limestone prairie in central Pennsylvania was analyzed by extracting soil cores from the current prairie, the edge of the prairie, and the surrounding forest. The seedling emergence method was used to germinate seeds for species identification. Although viable seeds of 12 native prairie species were present in soil samples from within the limestone prairie, only 9 and 4 native prairie species were present in the edge and surrounding forest soils, respectively . Thus, the richness of prairie propagules in the soil seed bank declined since the onset of woody plant invasion. Moreover, no viable seeds of Bouteloua curtipendu/a (Michx.) Torr., the dominant grass of limestone prairies, were detected, even within the prairie . Therefore, the soil seed bank of limestone prairies in Pennsylvania cannot be expected to contribute significantly to seedling recruitment during restoration efforts. As a rule of thumb, if the dominant or co-dominant plant species in a community does not generate a large andlor long-lived seed bank, then recruitment from the seed bank is not a viable method for ecological restoration .
Source: Natural Areas Journal
Publisher: Natural Areas Association, http://www.naturalarea.org