Seasonal Chlorophyll Change in a Leafy Liverwort

It is known that chlorophyll content of plant material varies with the season of the year, though the fact is sometimes lost sight of in studies of particular plant communities. Measurement of seasonal changes has been more often done with higher plants: e.g., Compton and Boynton (1945), Bordeau ( 1959). But Myiata and Hosokowa (1961) studied these changes in epiphytic mosses as correlated with photosynthetic efficiency. This paper reports on a study made during 1963-1964 of the chlorophyll content of the leafy liverwort, Scapania nemerosa (l.) Dumort, measured at monthly intervals for a period of one year. This plant material was especially suitable because pure strands of it, growing on a cliff in Duluth, Minn., were accessible at aIl seasons

Stress on the San Andreas fault: an analysis of shallow stress relief measurements made near Palmdale, California, 1979 and 1980

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Distribution in Minnesota of Acer Saccharum, Tilia Americana and Betula Lutea

The distribution in Minnesota of three tree species (Acer saccharum, Betula lutea and Tilia americana) of the northern hardwood type have been plotted, using data from the Third Forest Inventory of the Lake States\u27 Forest Experiment Station, herbaria records and records of occurrence from personal and other\u27s field work. Maps are presented that give more detailed distributions than have heretofore been available. All three species show concentration in a belt along the North Shore of Lake Superior. Acer saccharum and Tilia Americana show the expected close correspondence of distribution in this belt and in a broad extension westward, almost to the prairie margin. Befula lutea thins out rapidly as one proceeds west