Pacific Southwest Research Station

Evaluation of montane forest genetic resources in the Lake Tahoe Basin: implications for conservation, management, and adaptive responses of Pinus monticola to environmental change

Principal Investigators:
Detlev Vogler, USDA Forest Service-Pacific Southwest Research Station
David Neale, University of California-Davis
Tricia Maloney, University of California-Davis
Annette Delfino-Mix, USDA Forest Service-Pacific Southwest Research Station

Proposal [pdf]

Final Report [pdf]

Please contact Dr. Tricia Maloney with questions regarding the report.

Project Summary

An ecological genetic approach was used to determine genetic diversity and identify adaptive phenotypic variation in western white pine (Pinus monticola [Dougl.]) populations in the Lake Tahoe Basin (LTB). The objectives of the study were to:

1. Evaluate genetic variation for phenotypic traits related to growth, phenology, water-use efficiency, and patterns of resource allocation existing within and among populations of western white pine at a spatial scale of 1,300 km2
2. Determine the genetic structure and diversity of extant western white pine populations
3. Identify interactions between soil and climatic factors that influence standing levels of genetic variation for western white pine.

The results indicate that there is significant segregating genetic diversity for western white pine within the 1,300 km2 of the LTB. For western white pine, this segregating genetic diversity appears to have been structured by natural selection in the past; hence, if change continues to occur in the environmental variables that were important selective forces in the past, it is reasonable to hypothesize that these traits will continue to be important components of biotic responses to ongoing and future changes.

The results also emphasize the importance of considering comprehensive environmental datasets, including both climate and soil data, when studying phenotypic variation and evolutionary potential of tree species in the LTB.