La. Admin. Code tit. 43 § XV-5423

Current through Register Vol. 50, No. 11, November 20, 2024

Section XV-5423 - Revegetation: Standards for Success

A. Success of revegetation shall be judged on the effectiveness of the vegetation for the approved post-mining land use, the extent of perennial cover compared to the cover occurring in natural vegetation of the area, and the general requirements of §5417

1. Techniques for estimating cover shall be chosen from the following.

a. Pin Method. In the pin method, a pinpoint is lowered to the ground. If vegetation is encountered, a hit is recorded. If bare ground is encountered, a miss is recorded. Sample locations are distributed randomly throughout the area to be measured. Percentage of cover is the number of hits divided by the total number of points sampled. Each randomly placed pin is considered one sample unit.

b. Point Frame Method. In the point frame method, a group of pinpoints is lowered to the ground. If vegetation is encountered, a hit is recorded. If bare ground is encountered, a miss is recorded. Sample locations are distributed randomly throughout the area to be measured. Percentage of cover is the number of hits divided by the total number of points sampled. Each randomly placed frame is considered one sample unit.

c. Line Intercept Method. The sampling unit is a tape at least 100 feet long that is stretched from a random starting point in a randomly selected direction. The procedure consists of recording the length of tape underlain by vegetation, then dividing by the total length of tape to obtain the percentage of cover. Each randomly located tape is considered one sampling unit.

2. Techniques for estimating production shall be chosen from the following.

a. Clipping. A quadrat of appropriate size is randomly located within the area to be measured. Plants within the volumetric vertical projection are clipped and retained. All production samples shall be oven dried and weighed. The average oven-dried weight per sample is then converted to a production amount for the entire area.

b. Haying. A total harvest of the area to be measured may be used to establish production. The area is cut at a uniform height, the cuttings are windrowed and dried, and the air-dried hay is baled. Randomly selected bales are weighed. These weights are converted to a production amount for the entire area to be measured by multiplying the total number of bales by the average weight of the bales sampled.

c. Double Sampling. Each randomly located cluster is counted as one sampling unit. Plants will be clipped and reported by life form.

3. Technique for Estimating Live Stems Per Acre-Fixed Area Method. Sample locations are randomly established. The live stems within a specified radius of the sample point are counted. The average number of stems per plot is converted to stems per acre by multiplying by the appropriate conversion factor for the radius of the circle used.

4. Estimates of the mean for particular parameters shall be statistically valid. Sample adequacy shall be determined by the following formula:

N_min = (t²s²)/(dx)²

where:

N_min = the minimum number of observations needed;

t = 1.64 (the t table value for a double-tailed t test with infinite degrees of freedom at the 90 percent confidence level);

s² = the sample standard deviation;

d = the level of precision for the estimate of the mean; and

x = the sample mean.

Minimum sample size shall be 10. Sample adequacy must be met for cover, production, and/or woody plant densities.

5. Standards for success shall include criteria representative of unmined lands in the area being reclaimed to evaluate the appropriate vegetation parameters of ground cover, production, or stocking. Ground cover, production, or stocking shall be considered equal to the approved success standard when they are not less than 90 percent of the success standard. The sampling techniques for measuring success shall use a 90-percent statistical confidence interval (e.g., one-sided test with a 0.10 alpha error, two-sided test with a 0.05 alpha, etc.).

B. Standards for success shall be applied in accordance with the approved post-mining land use and shall be selected from the following.

1. For areas developed for use as pastureland, the ground cover and production of living plants on the revegetated area shall be at least equal to the standard for success selected from the following methods.

a. Reference Area. An area of at least 1 acre which will not be disturbed by mining and which is used in a direct comparison with reclaimed areas. As stated in §105, the reference area is to be maintained under appropriate management for the purpose of measuring the referenced vegetative parameters, and should be representative of the geology, soil, slope, and vegetation in the permit area.

i. Direct reference area comparisons are appropriate for pastureland.

b. The Historic Record. A suitable database for the historic record would consist of at least four growing seasons of data, collected to achieve sample adequacy. The historic record shall be based on vegetation data collected from premining areas or areas with plant communities comparable (cover, production, density, diversity) to the disturbed area and shall be established for each plant community or group of plant communities that will be disturbed by mining. The mean value for each parameter for each yearly sampling would be averaged to obtain an overall mean. This value would then be established as the success standard.

c. Technical Documents. Standards established by reference to technical documents of the USDA, USDI, or other authorities are allowed when specifically approved by the office. The office should be consulted prior to the use of this approach.

d. The criteria to be used by the office in approving technical documents for use in determining success standards in accordance with §5423. B.1 b-c, 5423.B.2.b-c, or 5423.B.3.b-c are as follows:

i. the technical documents are published by state or federal governmental agencies or educational institutions with a recognized expertise in agronomics, rain sciences or related disciplines;

ii. the technical documents are applicable to the area in which the permittee's operations are conducted;

iii. the technical documents are generally available to the public and to the office; and

iv. any technical document submitted for approval shall be considered an amendment to Louisiana's approved state program and shall be subject to the state program amendment process.

e. The criteria and procedures for determining ground cover and production success are found at §5424

2. For areas developed for use as grazingland, the ground cover and production of living plants on the revegetated area shall be at least equal to the standard for success selected from the following methods.

3. For areas developed for use as cropland, crop production on the revegetated area shall be at least equal to the standard for success selected from the following methods.

4. For areas developed for forestry, the ground cover and live stems per acre on the revegetated area shall be at least equal to the following standard for success.

a. At the time of final bond release there shall be 450 well-distributed free-to-grow live pine trees of the same age per acre or 250 well-distributed free-to-grow live hardwood trees of the same age per acre. Countable stems shall have utility for the approved post-mining land use, be healthy, and be a minimum of three years old. This standard has been developed after consultation and approval by the Louisiana Department of Agriculture and Forestry.

Free-to-Grow-pine seedlings or saplings without significant hardwood competition. Competing vegetation shades the pine's crown on less than 30 percent of the crown's circumference and the pines are judged to have better than a 90 percent chance of capturing a place in the crown canopy.

(a). This standard has been developed after consultation and approval by the Louisiana Department of Agriculture and Forestry.

(b). Vegetative ground cover shall not be less than 70 percent. This standard has been developed after consultation and approval by the Louisiana Department of Agriculture and Forestry.

Well-Distributed- uniform stocking levels over an entire planting site.

5. For areas developed for residential use, the vegetative ground cover shall not be less than 70 percent.

6. For areas developed for industrial/commercial use, the vegetative ground cover shall not be less than 70 percent.

7. For areas developed for recreation use, the vegetative ground cover shall not be less than 70 percent. The planting success standard for trees and shrubs will be established after consultation and approval by the Louisiana Department of Wildlife and Fisheries on a permit-specific basis. Trees and shrubs that will be used in determining the success of stocking and the adequacy of the plant arrangement shall have utility for the approved post-mining land use. At the time of bond release, at least 80 percent of the trees and shrubs shall have been in place for 60 percent of the five-year responsibility period. Trees and shrubs counted in determining such success shall be healthy and in place for not less than two growing seasons.

8. For areas developed for fish and wildlife habitat, the vegetative ground cover shall not be less than 70 percent. The planting success standard for trees and shrubs will be established after consultation and approval by the Louisiana Department of Wildlife and Fisheries on a permit-specific basis. Trees and shrubs that will be used in determining the success of stocking and the adequacy of the plant arrangement shall have utility for the approved post-mining land use. At the time of bond release, at least 80 percent of the trees and shrubs shall have been in place for 60 percent of the five-year responsibility period. Trees and shrubs counted in determining such success shall be healthy and in place for not less than two growing seasons.

a. The criteria and procedures for determining ground cover and stocking success are found at §5425

9. For areas with a post-mine designation of undeveloped, the vegetative ground cover, production or stocking shall be comparable to the standard for success for the highest and best managed land use that area is capable of supporting based on the information required by §2533. A.2 a

10. For areas previously disturbed by mining that were not reclaimed to the requirements of this Subpart and that are remined or otherwise redisturbed by surface coal mining operations, the vegetative ground cover shall be, at a minimum, not less than the ground cover existing before redisturbance and shall be adequate to control erosion.

1. The period of extended responsibility for successful revegetation shall begin after the last year of augmented seeding, fertilizing, irrigation or other work, excluding husbandry practices that are approved by the office in accordance with §5423. C 3

2. In areas of more than 26.0 inches of annual average precipitation, the period of responsibility shall continue for a period of not less than five full years. Vegetation parameters identified in §5423. B for grazing land or pasture land and cropland shall equal or exceed the approved success standard during the growing seasons of any two years of the responsibility period, except the first year. Areas approved for the other uses identified in §5423. B shall equal or exceed the applicable success standard during the growing season of the last year of the responsibility period.

3. The office may approve selective husbandry practices, excluding augmented seeding, fertilization or irrigation, provided it obtains prior approval from the director in accordance with 30 CFR 732.17 that the practices are normal husbandry practices, without extending the period of responsibility for revegetation success and bond liability, if such practices can be expected to continue as part of the post-mining land use or if discontinuance of the practices after the liability period expires will not reduce the probability of permanent revegetation success. Approved practices shall be normal husbandry practices within the region for unmined lands having land uses similar to the approved post-mining land use of the disturbed area, including such practices as disease, pest and vermin control; and any pruning, reseeding or transplanting specifically necessitated by such actions.

La. Admin. Code tit. 43, § XV-5423

Promulgated by the Department of Natural Resources, Office of Conservation, LR 5:395 (December 1979), amended LR 6:177 (May 1980), LR 14:441 (July 1988), LR 20:447 (April 1994), LR 21:1082 (October 1995), LR 29:1497 (August 2003).

AUTHORITY NOTE: Promulgated in accordance with R.S. 30:901-932.