|Shields Jr, Fletcher|
Submitted to: Ecological Restoration
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/2004
Publication Date: 6/1/2005
Citation: Martin, L. T., Pezeshki, S. R., Shields Jr., F. D. 2005. Soaking treatment increases survival of black willow posts in a large-scale field study. Ecological Restoration. 23(2):748-763.
Interpretive Summary: Native woody vegetation is an attractive method for streambank erosion control because of economic and environmental factors. Willow species are especially useful because they may be propagated by planting large cuttings (posts) that stabilize steep, eroding banks during the critical period of plant establishment. Anecdotal and laboratory evidence indicates that performance of such cuttings may be enhanced by soaking the posts in water for 10 days or more prior to planting. Survival and growth of soaked and unsoaked posts were compared after planting in plots representing a range of soil textures and elevations above shallow groundwater table. The soaked posts exhibited significantly higher survival rates, particularly in plots at higher elevations, which were drier. Soaked posts also outperformed unsoaked posts when grazed by beaver. These results verify that a relatively inexpensive technique may be used to enhance success of willow cuttings on eroding channel margins.
Technical Abstract: Restoration of damaged riparian ecosystems often includes the reintroduction of native, pioneer, woody species, including black willow (Salix nigra). Survival rates of willow have varied dramatically in previous projects, highlighting the need for techniques to improve survival. Described herein is an experiment testing the effectiveness of a pre-planting soaking treatment of willow posts on survival in a large-scale field study. Twenty plots were planted with eight soaked posts and eight unsoaked posts. First year results showed higher survival of soaked posts than unsoaked posts (64% and 53% respectively, p<0.1). Leaf chlorophyll content index (cci) was also higher in soaked posts than in unsoaked posts (8.42 cci and 7.92 cci, respectively, p=0.07). At high elevation plots (>110 cm above stream elevation at baseflow) survival of soaked posts was higher than unsoaked posts (71% and 43% respectively, p=0.07). Plots with severe damage from beaver herbivory (>40% of posts grazed) also exhibited higher survival of soaked posts compared to unsoaked posts (80% and 60%, respectively, p=0.05).