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Full-Text Articles in Life Sciences

Morphogenesis Of Douglas Fir Buds Is Altered At Elevated Temperature But Not At Elevated Co2, Martha E. Apple, Melissa S. Lucash, David M. Olszyk, David T. Tingey Oct 1998

Morphogenesis Of Douglas Fir Buds Is Altered At Elevated Temperature But Not At Elevated Co2, Martha E. Apple, Melissa S. Lucash, David M. Olszyk, David T. Tingey

Environmental Science and Management Faculty Publications and Presentations

Global climatic change as expressed by increased CO2 and temperature has the potential for dramatic effects on trees. To determine what its effects may be on Pacific Northwest forests, Douglas-fir (Pseudotsuga menziesii ) seedlings were grown in sun-lit controlled environment chambers at ambient or elevated (+4°C above ambient) temperature, and at ambient or elevated (+200 ppm above ambient) CO2. In 1995–1996 and 1996–1997, elevated CO2 had no effect on vegetative bud morphology, while the following unusual morphological characteristics were found with greater frequency at elevated temperature than at ambient: rosetted buds with reflexed and loosened outer …


Intrapopulation Sex Ratio Variation In The Salt Grass Distichlis Spicata, Sarah M. Eppley, Maureen L. Stanton, Richard K. Grosberg Jan 1998

Intrapopulation Sex Ratio Variation In The Salt Grass Distichlis Spicata, Sarah M. Eppley, Maureen L. Stanton, Richard K. Grosberg

Biology Faculty Publications and Presentations

In many dioecious plant populations, males and females appear to be spatially segregated, a pattern that is difficult to explain given its potentially high costs. However, in asexually propagating species, spatial segregation of the sexes may be indistinguishable from superficially similar patterns generated by random establishment of a few genets followed by extensive clonal spread and by gender-specific differences in rates of clonal spread. In populations where a significant fraction of individuals are not flowering and gender cannot be assigned to this fraction, apparent spatial segregation of the sexes may be due to differential flowering between the sexes. We confirm …


Genetic Markers In Plant Evolutionary Ecology, Mitchell B. Cruzan Jan 1998

Genetic Markers In Plant Evolutionary Ecology, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

Genetic markers have provided plant ecologists with a method of assessing levels of genetic relatedness among individuals and populations. In recent years a number of techniques based on DNA sequence variation have been developed to complement allozyme methods that are already widely used. Some of these new markers are more variable than protein-based markers, allowing more precise estimates of genetic differences among individuals and populations. Other DNA-based markers are based on organelle genomes that are inherited uniparentally. These cytoplasmic markers can provide a method for assessing the separate effects of seed and pollen dispersal on gene flow within and among …