2002-07-08_GENERAL DOCUMENTS - M2002004 (3)

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beds as seed sources for natural recruitment to meet these density requirements. Also more recently, the rapid increase in Wyoming big sagebrush seed costs has renewed the interest and/or raised questions as to whether transplantation is a viable option. In the next few paragraphs we will discuss the costs and potential for seedling transplantation to achieve the shrub density standards and compare that to direct seeding costs. Kleinman and Richmond (2000) stated that transplant stock for Wyoming big sagebrush can be more than $2.00 seedling'. Therefore, the cost to achieve 1 seedling m-2 on 20% of a hectare would require 2000 seedlings at a cost of $4000 ha' of reclaimed land. This would assume 100% survival which would be very optimistic considering the semiarid climate and highly variable precipitation of the region. Miekle (2000) cited estimates of 23 to 90% survival over 5 -6 years depending on whether sagebrush plants were fall or spring planted. However, he also states that there are very few actual studies where survival has been monitored. Numerous reclamationists have stated that survival of transplantation stock is very low. Therefore, if only 25% of the transplanted seedlings survive, then the initial cost of planting 8000 seedlings would be $16000 ha' Even if the cost could be reduced by 50 or 75% and survival was 100 %, the cost would still be $2000 and $1000 ha', respectively. Miekle (2000) proposes the use of "seed production plots" and "facilitation beds" for establishment of Wyoming big sagebrush on mined lands. The "seed production plots" would be developed using transplantation stock and planted in a windbreak fashion (maybe a single row) as a source of viable seed. "Facilitation beds" would be areas between the "seed production plots" that would lend themselves to natural recruitment of sagebrush from the "seed production plots." The facilitation beds would be planted to vegetation that is less aggressive/competitive and more susceptible to invasion by big sagebrush. The main concern with this approach is the fact that natural recruitment of Wyoming big sagebrush has been shown to be very limited and in fact is the premise for the success of managing or controlling big sagebrush with fire or herbicides. Sagebrush fruits are not structurally designed for wind or animal dispersal (West and Durham 1991); therefore, dispersal is limited to a few meters from the parent plant (Young and Evans 1989). In fact, it has been estimated that 85 -90% of the seeds fall within 1 m of the parent plant (Wagstaff and Welch 1990; Young and Evans 1989). Lyford (1995) reported that natural recruitment was very limited and only found 0.10 seedlings m' within 50 m of the native stand of 43 Wyoming big sagebrush when assessing several older mined land reclamation sites in Wyoming. He also concluded that the density of the native sagebrush plants had no effect on recruitment. Johnson and Payne (1968) also suggested that native sagebrush stands adjacent to treated areas was of no importance as a seed source for reinvasion due primarily to competition from grasses within the treated area. Miekle's (2000) proposed "facilitation beds" may help to alleviate some of the competition; however, no data was shown to evaluate this proposed practice. Another concern with natural recruitment from "seed production plots" is that Wyoming big sagebrush seedlings will not produce seed for the first 4 years (West 1988), thereby, limiting the chance of adequate seedling establishment and distribution to meet the shrub density requirement within the 10 year bonding period of reclaimed coal mined lands. The shrub density requirement must be met the last 2 years of the bonding period. Using data from two recent research studies accomplished in the Powder River Basin of Wyoming the following cost comparisons for direct seeding under several scenarios is offered. We assume that the seed used has 3500 seeds g' and that the seed is of good quality (example: 85 -90% viable and —25% PLS). To make the following estimates we used Wyoming big sagebrush seedling densities of4.0 and 7.5 seedlings m' observed after 2 years when seeded at the rate of 2 and 4 kg PLS ha' with a grass rate of 8 kg PLS ha' (Fortier 2000). We assume long -term survival rates of 33 and 59% obtained by Kriger et al. (1987) and Schuman (G.E. Schuman, unpublished data, 2000) and seed costs of $100, $200 and $300 kg' PLS for sagebrush seed. Seeding costs are not considered in this scenario because it is generally broadcast at the same time the grass mixture is being drilled and grass seeding would also be a cost in the transplantation scenario above. Table 1 shows the estimated cost per seedling and per 2000 surviving seedlings per hectare for two sagebrush seeding rates, the three sagebrush seed costs used and the two survivals. The number of 2000 seedlings ha' is used to represent the regulatory required density of 1 seedling m' over 20% of the land area (hectare). As is fairly evident, the cost of direct seeding, even considering the high seed costs, opportunity for successful establishment, and the long -term seedling survival, is a small fraction of the cost of nursery stock transplantation. If we were to use the best scenario of $0.50 per transplanted seedling and 100% survival and compare that to the highest direct seeding cost and lowest seedling survival rate; direct seeding would still only cost 9.6% of what transplantation would cost to