Though local adaptation could affect the success of revegetation projects, it is often not taken into consideration during restoration planning. The source of seed used to plant a restoration site may affect project success because seeds are best adapted to the area from which they were collected and may not do well in distant locales. However, the limited availability of large quantities of native plant seed often forces restoration practitioners to sow seed from a distant source. For many species used in revegetation projects, little is known about how far seeds can be planted from their collection source before exhibiting reduced vigor due to local adaptation. In order to better understand the effect of local adaptation on revegetation projects, we set up a reciprocal transplant experiment at five sites in New Mexico using winterfat (Krascheninnikovia lanata, Chenopodiaceae) as the study species. We compared the environments at each site using climatic, soil, and vegetative community data. We also compared the genetic differentiation among the existing populations using 9 allozyme loci. We examined local adaptation by measuring the growth and reproduction of individuals from different locales at the same sites for two years after transplanting.
Results/Conclusions
The climate, soil properties, and plant communities differed significantly at the five sites. However, though the transplants exhibited local differentiation in plant growth and reproduction, this differentiation was not adaptive. A potential explanation for this is our finding of low genetic differentiation among the five populations, as measured by allozyme variation, indicating a high level of gene flow among populations. These results have enhanced our knowledge of the potential for local adaptation to limit the viability of restoration projects.
