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o~~ o~~ • <br />~.o..~~~.~c~ <br /> <br />elsewhere have shown a tendency for species adapted to lower elevations to decline in <br />vigor following initial establishment when seeded in alpine environments. Good initial <br />stands may eventually die out altogether. Especially on non-topsoiled areas, use of <br />inorganic fertilizers can temporarily support improved agronomic species such as <br />smooth brome and timothy, but when fertilization is curtailed, without the ability to <br />cycle nutrients in the soil, stands may be lost. Plant litter may remain undecotnposed in <br />the soil for years because of low soil microbial activity. Another problem endemic to <br />many mining districts in the Colorado Rockies is the presence of pyritic media which <br />can oxidize to form sulfuric acid. Plant species will not tolerate the se~rere acid <br />conditions which can result from the oxidation of pyrite. Studies have shown that <br />liming treatments are not a permanently effective solution to this problem. <br />All of these problems-to some extent-may be considered characteristic of the Lake <br />Emma site. <br />Plot Layout and Construction <br />The field plot trials at Lake Emma have been designed to address the problems of acid <br />formation, nutrient cycling, and plant species adaptation. Figures 1 and 2 illu:>trate the <br />study design and plot layout. <br />The study comprises four plots on each of three growth media, for a total of 12 plots. <br />The media are (I) lake sediments, (II) lake sediments covered with six inches of fresh <br />topsoil, and (III) waste rock covered with six inches of fresh topsoil. The four plots on <br />each growth medium each comprise one of three treatments plus a control plot. Besides <br />the (1) control, these treatments are (2) organic amendment (manure + peat), (3) <br />organic amendment and pH control, and (4) organic amendment, pH control, and <br />fertilizer. Each plot is 14 feet by 15 feet. Each plot is designated by a two number <br />code: a Roman numeral to designate the growth medium and an Arabic numeral to <br />designate treatment. Plot I-2, for instance, is lake sediment amended with mature and <br />peat. <br />The Blots are situated near the south end of the Lake Emma disturbed area, just above <br />the outlet of the drainage diversion channel. The area is on fairly level gr;tde in a <br />location which will not be disturbed by mining activities. This area was selected in part <br />because there is a clear boundary between waste rock on the south half of the :u~ea and <br />lake sediments on the north half. Thus it was possible to have plots on waste rock and <br />lake sediments in a contiguous area, and to spread topsail on both in one operation. A <br />bucket loader was used to place topsoil on the plots. The topsoil came from stockpiles <br />recently constructed in connection with neazby open pit mining activities. Following <br />rough grading of the topsoiled plots, all plots were hand tilled with a spade atcd pick- <br />axe. Amendment materials, such as lime, manure and femlizer were carefully spread <br />on the appropriate plots according to the plot layout and design. Plots were then <br />thoroughly hand raked to incorporate amendments into the soil and to prepare a smooth <br />surface for seeding. All plots then were seeded with the same seed mixture and lightly <br />raked. Seeding of all plots took place on August 31, 1988. <br />-2- <br />