Laserfiche WebLink
and width of 2 meters. (If the grid distance is less than 50 meters, density belts will be <br />reconfigured to be 4 m X 25 m or similar configuration, but always totaling 100 m2.) <br />Determination of Ground Cover <br />Ground cover at each sampling site will be determined utilizing the point-intercept <br />methodology. This methodology will be applied as follows: First, a transect 10 meters in <br />length will be extended from the starting point of each sample site toward the direction of <br />the next site to be sampled. Then, at each one-meter interval along the transect, a "laser <br />point bar", "optical point bar" or 10-point frame will be situated vertically above the <br />ground surface, and a set of 10 readings recorded as to hits on vegetation (by species), <br />litter, rock (>2mm), or bare soil. Hits will be determined at each meter interval as <br />follows: <br />1. When a laser point bar is used, a battery of 10 specialized lasers situated along <br />the bar at 10-centimeter intervals will be activated and the variable intercepted by <br />each of the narrow (0.02") focused beams will be recorded; <br />2. If an optical point bar is used, intercepts will be recorded based on the item <br />intercepted by fine crosshairs situated within each of 10 optical scopes located at 10- <br />centimeter intervals. <br />3. If a 10-point frame is used, sharpened pins will be used to determine intercepts at <br />10-centimeter intervals. Care will be taken to NOT record "side touches" on the <br />pins as this will result in a significant overestimation error. <br />The following sampling rules should apply during data collection. Intercepts will be <br />recorded for the first (typically highest) current annual (alive during the current growing <br />season) plant part intercepted without regard to underlying intercepts or attachment to a <br />living base except when multiple strata are present. In this circumstance, multiple live <br />hits may be recorded, but only one hit per stratum with the second live hit being recorded <br />separately and not used to calculate total ground cover. Otherwise, the intercept will be <br />litter, rock or bare soil. Rock intercepts are based on a particle size of 2 mm or larger <br />(MRCS definition), otherwise it would be classified as bare soil. To distinguish between <br />current year senescent plant material and litter (including standing dead), the following <br />rule should apply: 1) if the material is gray or faded tan it should be considered litter; and <br />2) if the material is bright yellow or beige it should be considered current annual (alive) <br />and recorded by species. On occasion, experience with non-conforming taxa may <br />override this rule. <br />When using laser or optic instruments during windy field conditions, the observer should <br />consistently utilize one of the following techniques for determining a hit: 1) record the <br />first item focused upon that is intercepted by the narrow laser beam or cross-hair; 2) wait <br />a few moments and record the item intercepted for the longest time, or 3) block the wind <br />and record the intercept. When using a pin frame, the observer must wait for the wind to <br />subside. <br />4.15-30 Revision Date: 3/14/08 <br />Revision No.: TR-72