PARENT SESSION
Oral Session # 7: Populations and Genetics.
Presiding: E Sotka
Monday, August 4. 8:00 AM to 11:30 AM, SITCC Meeting Room 106.
Genetic and spatial analysis of Eastern White Pine on the Menominee Nation Forest.
Marquardt, Paula*,1, Echt, Craig2, Epperson, Bryan3, Pubanz, Dan, 1 USFS-North Central Research Station, Rhinelander, WI2 USFS-Southern Institute of Forest Genetics, Saucier, MS3 Michigan State University, East Lansing, MI
ABSTRACT- To ensure sustainability of forest resources, we must explore the effects of silvicultural treatments on all aspects of resource management. While we often focus on easily measured phenotypes, effects at the genetic level have been largely ignored. Understanding the genetic implications of management practices may assist us in avoiding future bottlenecks. To supply basic information on white pine genetic diversity for native, managed and locally regenerated populations, six stands of eastern white pine were evaluated across the 237,000-acre Menominee Nation Forest, Menominee County, WI. Five of the sites are actively managed, while in the sixth no records exist of live pine being cut (SP). Of the five managed stands, one was regenerated as a white pine plantation (EL), three are under shelterwood management (PP, C1, OL) and one a pine release management site (MC). Fifty over-story white pine trees were sampled for genetic analysis at eight microsatellite DNA loci for each stand except EL, where samples for DNA analysis were taken from planted stock. In addition, 50 regenerated seedlings were sampled from C1, OL and MC. Genetic diversity was high and maintained among native and managed sawtimber populations (mean He = 0.58 + 0.22) and locally regenerated populations (mean He = 0.56 + 0.23). The plantation also contained high levels of genetic diversity (mean He = 0.51 + 0.23). There was less than 2% genetic divergence among all populations (mean Fst = 0.014). Inbreeding was significantly increased above Hardy-Weinberg equilibrium for both the parents (mean Fis = 0.20 + 0.14) and seedlings (mean Fis = 0.14 + 0.16). These results indicate some spatial family structure, which is a major factor in bi-parental inbreeding. Spatial structure among the sampled trees within each population was weak and variable, which was not unexpected since the populations have been disturbed and sampled in various ways. The greatest positive spatial structure was found in the first distance class for SP, the least disturbed population. Based on the mean Moran's I value of 0.008, Wright's neighborhood size (Ne) for the SP population was approximately 300 trees.
Key words: sustainability, Pinus strobus , population genetics, microsatellite