Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Natural Resources

Department name when degree awarded

Range Science

Committee Chair(s)

Martyn M. Caldwell


Martyn M. Caldwell


Herman H. Wiebe


David L. Turner


Surface mines in mountainous areas cause environmental deterioration at lower elevations in the watershed. The most successful long term solution to the downstream problem is revegetation. However, mine spoils are low in essential plant nutrients, have low water holding capacity, and are often acidic. These factors limit plant colonization. Plants must also be adapted to the environmental conditions of high elevations.

At the McLaren Mine, }1ontana, at 2800 m, it was observed that seedlings on revegetation plots were desiccated, indicating possible water deficits. Field and growth chamber studies were carried out to determine the effects of some spoil ameliorating treatments on leaf water potentials, leaf pressure potentials and seedling development and mortality. Poa alpina L. and Alopecurus pratensis L., the two plant species seeded are successful revegetation species in the area. The four treatments were: 1) a control group with no spoil treatment, 2) peatmoss incorporated into the spoils, 3) a surface mulch of jute net, and 4) peatmoss-plus-jute net.

Results showed a decrease in water stress experienced by plants on plots with spoil ameliorating treatments. The jute net, or peatmoss-plus-jute net treatments were the most effective in reducing water stress. Leaf pressure potential data were extremely variable, making it difficult to determine trends.

In the field seedling mortality was reduced on plots with jute net or peatmoss--plus-jute net. No trends were apparent in the growth chamber study. In both studies seedlings were larger with jute net or peatmoss-plus-jute net treatments.