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slopes and aspects. Mulches are expected to decrease fluc- <br /> <br />• ~. tuations in soil surface temperature by intercepting some of <br />the solar radiation at the soil surface, and by reducing heat <br /> loss at night. The mulch is also intended to reduce the rate <br /> of soil moisture loss because of cooler soil temperatures and <br /> diminished exposure to air movement at the surface. <br /> Figure 2.1-1 is a diagram of the plot design. Due to space coa- <br /> straiats, only one control replication was installed for each mixture on <br /> each slope. The lack of control replication and the lack of all pos- <br /> sible mulch treatments oa all slopes results in an unbalanced statis- <br />i <br />tical design. The effect of this design on the statistical analysis is <br /> discussed i.n the Data Analysis section. <br /> 2.2 Plot Construction <br /> Methods used to construct plots and seed them are described in the <br /> First Annual Report (ERT 1979). <br /> 2.3 Data Collection <br />` 2.3.1 Soil Temperature and Moisture Measurements <br />(- Field measurements were taken with a Soil Test HC-300B Soil <br />' Moisture-Temperature Meter at two week intervals beginning on Hay 4 and <br /> concluding oa tiovember 4. The dau sheet used to record data is shown <br />1 in Figure 2.3-1. Readings were taken between 15D0 and 1600 on measure- <br />") meat days. <br /> 2.3.2 Vegetation Cover and Density Measurements <br /> Plot canopy cover and density estimates were performed on Hay 23, <br />'• 1979 and cover data were collected again on September 12, 1979. Density <br />'- data were not collected in October because dormant plants could not be <br /> distinguished from dead plants. <br />~_ A .2 z .5 m (.1 m) rectangular sampling quadrat was used to sample <br /> cover and density is all treatments. Five randomly located quadrats <br /> were sampled is each treatment. Randomization was achieved on 4:1 plots <br /> by dividing the plots into a grid consisting of nine equally spaced <br /> uaits.on the vertical and horizontal axes. The origin was located at <br /> the lower left hand corner of the plot. The grid was modified to allow <br /> a .25m buffer along the edges of each plot. Random number pairs were <br /> taken from a random numbers table to locate a position on the vertical <br /> axis (first digit) and a point on the horizontal axis (second digit). <br /> The conjunction of the two points marked the lower left hand corner of <br /> <br /> <br />3 <br />