GENERAL33208 - Laserfiche WebLink

Home Browse Search

~. c INTRODUCTION A noxious weed control and monitoring program was initiated in 1998 by the Division of Minerals and Geology (DMG), at the inactive Coal Basin Mine. DMG, in conjunction withPitkin County, was awazded a grant from the Colorado Department of Agriculture, for the purpose of managing serious noxious weed infestations that had developed at various reclaimed area locations within the permit boundary. The mine permit area is located within the upper reaches of the Coal Creek drainage, approximately four miles west of Redstone. Coal mining activities began in the permit area vicinity in the 1890's, were discontinued in the early 1900's, and resumed on a much lazger scale in the mid-1950's. Mid-Continent Resources (MCR) and its predecessors operated a complex of five underground mines and associated processing and transportation facilities within Coal Basin from about 1955 until 1990, Tn the eazly 1990's, the mine ceased operation. MCR filed for Chapter 11 Banlauptcy protection, and began to liquidate its assets. Eventually, MCR's mining permit was revoked and the reclamation bond forfeited by the Colorado Mined Land Reclamation Board. As required by applicable statute, the Colorado Department of Natural Resources, Division of Minerals and Geology, undertook the task of reclaiming the mining disturbances through the use of funds obtained from the bankruptcy liquidation plan. Mine reclamation is now largely completed. The weed control program was initiated to manage significant infestations of noxious weeds that were present on approximately 60 acres of reclaimed land within lower portions of the Coal Basin complex. Weed infested reclaimed sites included a conveyorbeldine corridor and coal stockpile area, a coal refuse pile known as the Sutey Pile, and associated facility azea disturbances. Average elevation of the treatment azeas was 9,000 to 9,500 feet above sea level. Primary target species wereplumeless thistle (Carduus acanthoides) and houndstongue (Cynoglossum o~cinale), both biennials; and the perennial Canada thistle (Breea arvense). Secondary species of concern were the biennial musk thistle (Carduus nutans) and the perennial oxeye daisy (Chrysanthemum teucanthemum). A number of organizations and agencies have participated in the project by offering in-kind services, funding, or materials. Partners in the project in addition to DMG andPitkin County, included the U.S. Forest Service, the Office of Surface Mining, and the Aspen Wilderness Workshop. Program goals were to reduce the severity of noxious weed infestation to allow for establishment of desirable and effective vegetation cover and minimize the risk of spread to adjacent undisturbed areas. Initially, athree year control program was envisioned, with continued treatment as wan•anted. Control program objective was a 75% reduction in noxious weed density within the treatment areas. Tordon (picloram) a[ one or two quarts per acre has been applied to each treahnent azea at least annually in early July, since 1998, using a combination of truck mounted and backpack spraying equipment. Spray operations were conducted twice per year (eazly July and September), in 1998 and 2000. The two quart per acre application rate was typically used, with the lower rate applied in portions of the treatment azeas where infestations were less severe. ht ZOOQ goat grazing combined with mechanical control (chopping ofun- grazed plumeless thistle flowering stalks) andinterseeding was applied to certain sites. Although not a planned control agent, a heavy larval infestation of the painted lady butterfly Q~anessa cardut) was observed on remaining thistle patches within portions of the azea in 2001. The primary purpose of this report is to summarize the results of monitoring that was conducted annually from 1998 through 2001. In order to document appazent treatment effectiveness, four reference sites were established in representative locations within the treatment azeas. Refer to Map 1 for the various treatment azea locations, and approximate locations of Reference Areas 1 through 4. Noxious weed densities and cover based vegetative species composition data were collected within the reference sites prior to initial treatment in June 1998, and data were collected within the same reference sites just prior to summer spraying operations in 1999, 2000, and 2001. Success of the program with respect to tazget species control was based primarily on noxious weed density data, while the species cover and composition data ailowed for assessment of plant community response and apparent impacts to non-target vegetation.