Journal of Heredity Advance Access originally published online on June 22, 2006
Journal of Heredity 2006 97(4):409-416; doi:10.1093/jhered/esl008
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Population Differentiation and the Effects of Herbivory and Sand Compaction on the Subterranean Growth of a Desert Lily
From the Mitrani Department of Desert Ecology, Jacob Blaustein Institute for Desert Research, Ben Gurion University of the Negev, Sede Boqer 84990, Israel (Ruiz-R., Ward, and Saltz); the Department of Biology, National University of Colombia, Bogotá A.A. 7495, Colombia (Ruiz-R.); and the School of Biological and Conservation Sciences, University of KwaZulu-Natal, P. Bag X01, Scottsville 3209, South Africa (Ward)
Address correspondence to D. Ward at the address above, or e-mail: ward{at}ukzn.ac.za.
Differences in level of herbivory can select for local adaptation and genetic differentiation of plant populations in different environments. Mean bulb depth of the desert lily Pancratium sickenbergeri, differs considerably among populations differing in the level of herbivory by the dorcas gazelle. The gazelle digs in the sand to remove most of the bulb of the lily. Deeper bulbs have less material removed by herbivory than shallow bulbs and have higher fitness. A possible confounding factor is the degree of sand compaction, which may retard the downward growth of the bulb. We conducted a common garden experiment with 2 sand types with seeds from source populations with different levels of herbivory. There was a large genetic difference among populations. Two of 3 analyses indicated that there was an interaction between population and sand type, indicating that there is a heritable component of plasticity.