Physical Sciences and Mathematics Commons^™

Gas Exchange And Water Relations Of Two Alpine And Two Arctic Tundra Plant Species, Douglas Allan Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Although water stress is an important selective force in many environments, it is not commonly considered to be of particular importance in tundra areas. Even though large portions of tundra may have an abundance of water, other more exposed areas may become quite dry. This microsite variability with respect to moisture stress was reflected in soil water potential measurements obtained from an alpine tundra area on Niwot Ridge in Colorado. Even though soil water potentials were consistently above -5 bars in a relatively low lying Deschampsia meadow, soil water potentials from an exposed fellfield area were often as low as …

Respiratory Metabolism And Energy Requirements Of Embryo, Larval And Juvenile Mountain Whitefish, Prosopium Williamsoni, Pokkavil Karunakara Rajagopal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The upper optimum temperature for embryonic development of mountain whitefish is 6 C, and for the post yolk sac stage is 9 to 12 C. The need to know effects on all stages in the life cycle in cases of thermal pollution is demonstrated. Abnormalities caused by thermal pollution in hatched larvae were agape jaws, coloboma or fissure of the eye, monophthalmia or the presence of only one eye, monomicrophthalmia or the presence of one small eye and one case of twinning. High mortalities of eggs occurred at 9 C and higher.

Study of the energy expenditure, by the dry …