|Shields Jr, Fletcher|
Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2006
Publication Date: 10/1/2006
Citation: Greer, E., Pezeshki, S.R., Shields Jr, F.D. 2006. Influences of cutting diameter and soil moisture on growth and survival of black willow, salix nigra. Journal of Soil and Water Conservation. 61(5) 311-323. Interpretive Summary: Willow trees rooted from cuttings are often planted to stabilize eroding streambanks, but little is known regarding techniques to improve often poor planting performance. Willow cuttings with basal diameters measuring 1 cm, 5 cm, or 10 cm were grown in a greenhouse under three soil moisture regimes, including droughty, well-watered and periodic flooding. The 10 cm cuttings tended to produce the most biomass (leaves, shoots, and roots), while survival rates were slightly better for 1-cm cuttings. These findings will be useful to anyone planning and designing streambank stabilization projects involving planting willow cuttings.
Technical Abstract: Streambank restoration projects often involve planting large-diameter black willow (Salix nigra) cuttings otherwise known as posts. However, the potential exists that smaller size cuttings alone or in combination with larger ones may improve success efforts. Therefore, a greenhouse study was conducted to quantify performance of different-sized cuttings under harsh conditions typical of streambanks. Replicated cuttings with basal diameters measuring 1 cm, 5 cm, or 10 cm were placed in three soil moisture regimes including well-watered, periodic flooding and drought. Biomass accumulation and partitioning, height, and survival were measured. Under periodic flooded conditions 10 cm cuttings had greater leaf number and weight (p<0.05), leaf area index (p<0.05), shoot weight (p<0.05), root weight (p<0.05), and height growth (p<0.05) compared to 1 and 5 cm cuttings. Survival was best for 1 cm cuttings in all three moisture regimes (100%) and for 10 cm cuttings under flooded conditions (100%). Growth and biomass of 10 cm cuttings were reduced by drought compared to periodic flooding treatment (p=0.02). Thus using 1 cm cuttings of black willow in any given moisture regime may lead to increased survival rates. Planting larger cuttings, however, may improve overall restoration success. The technique of planting a combination of these two diameters may help to further stabilize streambanks.