A Guide to Soil Quality Monitoring for Long Term Ecosystem Sustainability on Northern Region National Forests

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Plant Community Classification for Alpine Vegetation on the Beaverhead National Forest, Montana
PRODUCTIVITY/MANAGEMENT AND SOIL EXCERPTS

[Excerpted from: Cooper, Stephen V.; Lesica, Peter; Page-Dumroese, Deborah. Rev. 1997. Plant Community Classification for Alpine Vegetation on the Beaverhead National Forest, Montana. Gen. Tech. Rep. INT-362. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 61 p.]

SNOWBED COMMUNITIES

Carex nigricans c.t.
(CARNIG; Black Alpine Sedge)

Soils—Parent materials were limestone, granite, and gneiss. Bare ground and gravel covered only 2 percent of the surface. Mean depths of litter and duff were 0.4 and 0.2 inch. Percent of coarse fragments were always less than 10 percent with a mean of 3 percent. Modal texture of the fine fraction was sandy clay. Soil pH was 6.5 at the limestone site and varied between 5.8 and 6.2 when parent materials were crystalline. Mean pH was 6.2. Mean organic matter content was 15 percent, mean total nitrogen was 0.36 percent, and C:N ratio was 20:1. Soils in late July of 1992 were always wet and cold.

Productivity/Management—Due to retarded phenology in 1991, we measured productivity in only two stands. Graminoid productivity had a mean of 375 lbs per acre, and forb productivity had a mean of 275 lbs per acre. Mean productivity of dwarf shrubs was 22 lbs per acre. Mean total productivity was 650 lbs per acre. Carex nigricans was not fully mature when we clipped plots in these stands; thus, our estimates of graminoid and total productivity are low.

Juncus drummondii/Antennaria lanata c.t.
(JUNDRU/ANTLAN; Drummond’s Rush/Woolly Pussytoes)

Soils—Parent materials were gneiss and granite. Bare ground and gravel covered 50 percent of the surface. Mean depths of litter and duff were both 0.1 inch. Percent of coarse fragments ranged from 6 to 17 percent with a mean of 13 percent. Modal texture of the fine fraction was sandy clay. Although they occurred in topographically low positions, these relatively barren and unproductive communities were apparently underlain by shallow and perhaps excessively well-drained soils. Soil pH ranged from 6.0 to 6.1 with a mean of 6.1. Mean organic matter content was 12 percent, mean total nitrogen was 0.21 percent, and C:N ratio was 24:1.

Productivity/Management—Graminoid productivity varied between 200 and 270 lbs per acre with a mean of 237 lbs per acre. Forb productivity ranged from 150 to 860 lbs per acre with a mean of 460 lbs per acre. Productivity of dwarf shrubs in one stand was 30 lbs per acre. Mean total productivity was 726 lbs per acre. Highest productivity occurred on the deepest soils.

Phyllodoce empetriformis/Antennaria lanata c.t.
(PHYEMP/ANTLAN; Mountain-Heather/Woolly Pussytoes)

Soils—Parent materials were granite and quartzite. Cover of bare ground and gravel was 15 percent with 8 percent cover of rock. Mean depths of litter and duff were both 0.1 inch. Percent of coarse fragments varied from 0 to 14 percent with a mean of 7 percent. Modal texture of the fine fraction was sandy clay-loam. Soil reaction ranged from 6.0 to 6.4 pH with a mean pH of 6.1. Mean organic matter content was 14 percent, mean total nitrogen was 0.30 percent, and C:N ratio was 23:1. Soils underlying PHYEMP/ANTLAN were relatively deep and generally still moist in late July.

Productivity/Management—We measured productivity in only two stands; the heather species proved difficult to clip accurately. Thus, our production estimates are only rough approximations. Mean shrub productivity was 166 lbs per acre. Graminoid productivity had a mean of 133 lbs per acre, and forb productivity had a mean of 104 lbs per acre. Mean total productivity was 403 lbs per acre.

Cassiope mertensiana/Carex paysonis c.t.
(CASMER/CARPAY; Merten’s Moss-Heather/Payson’s Sedge)

Soils—Parent materials were quartzite, gneiss, and granite. Bare ground and gravel, covered 11 percent of the surface, while rock cover was 8 percent. Mean depth of litter was 0.2 inch, and mean depth of duff was 0.1 inch. Coarse fragment percent varied from 9 to 35 percent with a mean of 23 percent. Modal texture of the fine fraction was sandy clay. Soil pH ranged from 5.8 to 6.2 with a mean of 6.0. Mean organic matter content was 19 percent, mean total nitrogen was 0.52 percent, and C:N ratio was 19:1. Soils were moderately deep and moist to wet in late July.

Productivity/Management—We measured productivity in only one stand; Cassiope was difficult to clip accurately. Thus, our production estimates are only rough approximations. Shrub productivity was 237 lbs per acre, graminoid productivity was 267 lbs per acre, and forb productivity was 712 lbs per acre. Total productivity was 1,216 lbs per acre.

Juncus Parryi/Erigeron ursinus c.t.
(JUNPAR/ERIURS; Parry’s Rush/Bear Fleabane)

Soils—Parent materials in the two stands were andesite and quartzite. Bare ground and gravel covered 47 percent of the surface, making this the most barren of our snowbed communities. Mean depths of litter and duff were 0.3 and 0.1 inch. Mean coarse fragment content was 25 percent. Modal texture of the fine fraction was clay. Mean soil pH was 5.6. Mean organic matter content was 20 percent, mean total nitrogen content was 0.64 percent, and C:N ratio was 15:1. This sparsely vegetated community type is similar to JUNDRU/ANTLAN, but the soils were even more stony and acidic.

Productivity/Management—Mean graminoid productivity was 439 lbs per acre, and mean forb productivity was 253 lbs per acre. Mean total productivity was 692 lbs per acre. Productivity is probably affected more by the shallow, poorly developed soils than late snow release.

Salix glauca c.t.
(SALGLA; Glaucus Willow)

Soils—Parent material was calcareous sandstone. Exposed ground and gravel constituted 6 percent of the surface. Depths of litter and duff were 1.0 and 0.5 inch. The high surface organic matter probably reflects low rates of decomposition due to low insolation and late snowmelt. Percent of coarse fragments was very different for each microsite but averaged 30 percent for the stand. The texture of the fine fraction was sandy loam. Soil pH was 7.6. Organic matter content was 14 percent, mean total nitrogen was 0.31 percent, and C:N ratio was 28:1.

Productivity/Management—Our estimates are based on only three clipped plots in one stand and should be considered only rough approximations. Salix glauca produced 759 lbs per acre. Graminoid productivity was 12 lbs per acre, and forb productivity was 759 lbs per acre. Total productivity was 1,530 lbs per acre.

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