Polyploid organisms often have different geographic ranges than their diploid relatives. However, it is unclear whether this divergence is maintained by adaptation or results from historical differences in colonization. Here we conducted a reciprocal transplant experiment with diploid and autotetraploid Chamerion angustifolium to test for adaptation at the ploidy and population level. In the Rocky Mountains, pure diploid populations occur at high elevations and pure autotetraploid populations occur at low elevations with mixed-ploidy populations between. We planted 3134 seedlings in 2004 and 3890 juveniles (bolting) in 2005 among nine plots, three in each of the diploid, mixed-ploidy and tetraploid zones, and monitored survival until 2008. For both seedlings and juvenile plants, elevation significantly influenced survival. The juvenile plants also showed a significant ploidy by elevation interaction, indicating that diploids and tetraploids survived best at their native elevations. In contrast, we found no evidence of local adaptation to plot within elevation. This suggests that the current distribution of diploids and tetraploids across elevations is the result of adaptation and that genome duplication may have facilitated the invasion of lower elevation habitats by limiting the movement of maladapted alleles from diploid populations at higher elevations.
Usage Notes:
Martin and Husband Diameter Height Data
This file contains diameter measurements for seedlings of Chamerion angustifolium, grown from field collected seed, reared in the green house and planted into 9 plots in the Canadian Rocky Mountains. (See paper for details.) Read me on first sheet of work book.
Martin and Husband Survival Data
This data represents information on the survival of Chamerion angustifolium seedlings (2004) and juveniles (2005) transplanted in to 9 plots in the Canadian Rocky Mountains. See paper for details. Read mes included in workbook.
Martin and Husband Vegetation Survey
Data collected during vegetation survey conducted in 2005 at the 9 plots involved in the experiment in the Canadian Rocky Mountains. (Read me included.)
Martin and Husband Weather Data
This file contains daily meteorological data downloaded from Environment Canada (http://climate.weatheroffice.ec.gc.ca/climateData/canada_e.html) as csvs covering 1 year of data each and amalgamated.
Specifically, the available data was downloaded for 9 stations in the Canadian Rocky Mountains for the period from 1997 to 2007. Station information and read me included in the data file.