Conifer restoration on lakeshores using 3 planting techniques

摘要

Interest in lakeshore habitat restoration has increased concomitant with growing awareness of the importance of these areas for maintaining water quality and for providing terrestrial and aquatic wildlife habitat. Lakeshore restoration efforts are often limited by the high cost of suitable plant material. We compare the effectiveness of containerized and more cost-effective bareroot and innovative gravel-culture planting techniques for 5 conifer species: balsam fir (Abies balsamea (L.) Mill. [Pinaceae]), white spruce (Picea glauca (Moench) Voss [Pinaceae]), red pine (Pinus resinosa Aiton [Pinaceae]), eastern white pine (Pinus strobus L. [Pinaceae]), and northern white cedar (Thuja occidentalis L. [Cupressaceae]). Plantings were monitored for4 growing seasons (year of planting and 3 subsequent). Annual growth rates for 4 of the 5 species did not differ significantly among planting techniques. The exception was containerized balsam fir, which experienced a greater height growth rate than did barerootand gravel-culture stock. Survival of gravel-culture stock was greater than that of bareroot stock and similar to that of containerized stock for all of the conifers examined, except for red pine. Red pine gravel-culture stock had the lowest survival ofany species or treatment (29%), suggesting that this technique is poorly suited for this species. We conclude that the time frame for bareroot native conifer planting may be extended for most of the species examined through the midsummer months by growing bareroot stock in irrigated gravel medium until lifting and planting. For some species, however, neither bareroot planting technique is likely to equal or exceed the growth and survival of containerized stock in lakeshore restoration.