Individual study: Feasibility of out-planting small populations of spreading globeflower Trollius laxus in a forested fen in central New York, USA
Scanga S.E. (2014) Feasibility of out-planting small populations of spreading globeflower Trollius laxus in a forested fen in central New York, USA. Conservation Evidence, 11, 48-52
Where sufficient seeds of a rare plant species are available, out-planting small populations may be an effective conservation practice, given certain rare species persist naturally as small populations, sometimes within metapopulations. I investigated the feasibility of out-planting small populations of the rare and declining fen plant spreading globeflower Trollius laxus, which is easily grown in greenhouse and garden settings. In 2004 greenhouse-raised seedlings were planted at 14 plots (n = 10 plants per plot) located within a protected area where a well-studied metapopoulation of T. laxus already occurred. Suitable plots were identified using a GIS-based, macroscale habitat model; seven were under canopy gaps and seven were under intact canopy. The populations were monitored one, two, three and eight years after out-planting. Two plots that were lost less than one year after out-planting were not included in subsequent monitoring and analysis. I compared survival between gap and non-gap populations and quantified the vigour of the surviving plants over time. Overall, survival was very poor (only 10 of the original 120 transplants survived to year eight), but surviving plants were vigorous, showing increases in size and flower production. Plant survival to year three was significantly greater under canopy gaps than intact canopy. These results suggest that out-planting T. laxus at new sites may be difficult, that success will be greater under canopy gaps than intact canopy, and that out-planted populations may need regular supplementation with new transplants in order to be viable over the long-term.