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Full-Text Articles in Life Sciences
Some Effects Of Prescribed Fire At Cedar Creek Natural History Area, A. N. Axelrod, F. D. Irving
Some Effects Of Prescribed Fire At Cedar Creek Natural History Area, A. N. Axelrod, F. D. Irving
Journal of the Minnesota Academy of Science
On four oak savanna restoration compartments with a total area of 100 acres, annual burns (1965-1972) reduced the percent of milacre plots stocked with hazel to 39 compared with 65 on unburned areas. Four growing seasons after one and three fires the hazel distribution was not significantly different from the control. Annual burns increased the density of hazel stems in clones to 19.5 per .0001 acre compared to 11.0 on controls. Stem density four years after 1 and 3 burns averaged 10.0 and 8.0 per .0001 acre. The o.d. weight of live hazel stems per .0001 on annual burn areas …
Energy Potential Of Cattails (Typha Spp.) And Productivity In Managed Stands, N. J. Andrews, D. C. Pratt
Energy Potential Of Cattails (Typha Spp.) And Productivity In Managed Stands, N. J. Andrews, D. C. Pratt
Journal of the Minnesota Academy of Science
Because of their high productivity in both natural and managed stands, cattails are being considered as a potential "energy crop". Yields of 40 tons per hectare, including above and below ground biomass, have been reported (Moss et al., 1977). Yields from plants grown in managed paddies on peat are generally 20-30 percent lower. The maximum shoot weight occurs in August while maximum below ground biomass is reached in October. Total biomass increased with increasing rates of fertilizer application but differences were not significant. Differences between the initial nutrient contents of the two peat types used were more important than fertilizer …
Unialgal Growth Of Anabaena And Dictyosphaerium In Lake Itasca, Charles P. Mason
Unialgal Growth Of Anabaena And Dictyosphaerium In Lake Itasca, Charles P. Mason
Journal of the Minnesota Academy of Science
A relatively new field technique was employed to determine the growth of algae in natural waters. Anabaena sp. (Cyanophyta) and Dictyosphaerium sp. (Chlorophyta) were grown in separate membrane filter chambers situated in Lake Itasca and LaSalle Lagoon, a sewage effluent pond. Physical and chemical determinations before and after each two-week experiment were correlated with changes in algal biomass. Wet weight determinations of Anabaena were twice as great in the lake as in the sewage lagoon, while Dictyosphaerium growth was the same in both habitats. Nitrogen (nitrate and nitrite) was 0.09 • 0.2 mg/1 in the lagoon and from less than …
The Elongation Of The Leaf Of Cyclamen Persicum Mill. (Cultivars), Marshall D. Sundberg
The Elongation Of The Leaf Of Cyclamen Persicum Mill. (Cultivars), Marshall D. Sundberg
Journal of the Minnesota Academy of Science
The leaves of three cultivars of Cyclamen persicum were examined at several stages of development in order to determine the pattern of elongation in both the lamina and petiole. Although there is a considerable literature on lamina elongation, relatively little is known about the growth of the petiole. In the latter structure it is usually assumed that an intercalary meristem is involved. Elongation of the young leaf is initially due to activity distributed throughout the deve1opint organ. Maturation of the leaf progresses acropetally from the base of the petiole and basipetally from the tip of the lamina. As the leaf …
Effects Of Nutrients On Productivity And Morphology Of Typha Angustifolia X Latifolia, V. Bonnewell, D. C. Pratt
Effects Of Nutrients On Productivity And Morphology Of Typha Angustifolia X Latifolia, V. Bonnewell, D. C. Pratt
Journal of the Minnesota Academy of Science
The productivity of natural stands of cattails (Typha latifolia) has been correlated with the amounts of nutrients in the soil and water by Boyd and Hess (Ecology, 51: 296, 1970). The direct effects of varying levels of nitrogen (N), phosphorus (P) and potassium (K) on productivity were examined in our study by growing cattails in Hoagland's nutrient solution. Concentrations of ¼, 1/16, and 1/64 the amount of N present in complete Hoagland's solution (0.01Ml resulted in 63 percent, 48 percent and 26 percent of the dry weight of plants grown in complete solution. Rhizomes used to start plants contained considerable …