Life Sciences Commons^™

Plant Succession Studies On Subalpine Acid Mine Spoils In The Beartooth Mountains, Patricia Lea Howard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Large areas within alpine and subalpine tundra have been by disturbed by mining during this century. The most promising method for retarding deterioration of these areas is revegetation with native species through both seeding and transplants. One natural process of revegetation which occurs on portions of many existing disturbances seems to be the establishment of a few species that expand with time to form matts of plants.

At the McLaren Mine, located at 3000 m elevation in the Beartooth Mountains, Montana, active succession is occurring and is dominated by Carex species. Seed viability and successional patterns studies were conducted on …

Leaf Development Of Rumex Patientia L. Exposed To Uv Irradiation (280-320 Nm), Judith G. Dickson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two factors which affect leaf ontogeny and ultimate leaf size: (1) the rate and duration of cell expansion, and (2) the rate and duration of cell division, were examined for their role in the slowed early growth rate and smaller ultimate leaf size when plants are exposed to ultraviolet-B (UV-B) radiation. Rumex patientia L. was grown in controlled environment chambers under enhanced UV-B radiation (equivalent to daily solar UV-B irradiation at 40°N latitude in mid-May with an atmospheric ozone concentration of 0.20 atm-cm) and control treatments. The pattern of growth as expressed in changes of mean cell size of two …