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Germination of Green and Gray Rubber Rabbitbrush and Their Establishment on Coal Mined Land

J. T. Romo, L. E. Eddleman
1988 Journal of range management  
The objective8 of tbia study were to: (1) determine tbe effecta of temperature and water stress on germination, and; (2) evaluate effects of seeding date on emergence and auvival of green and gray rubbermbbitbNeb(Clvysollromnc nauwanu(PaUas)Britt. sulmp. graveole~ (Nutt.) Piper. md Chrysothanmus nauseosla (P8UM) Britt. subep. nuuscosus (Nutt.) Piper.). Seeds of botb sbruba were incubated at 10,20, and 300 C in a gradient of osmotic potentials ranging from 0.0 to -1.5 MPa. Seedings were also
more » ... dings were also made in tht field on reeding dates over a period of 3 years. Total germination and germination rate declined aa temperaturen end osmotic potential8 decreased; they wtre bigbest for both sbruk at 20 and 300 C and lowest at 10" C. Under field conditions seedling populationa wert limited by low emergence and survival relative to viable seed planted. Emergence and survival of aeedlinga were highest in an exceptionally wet year, declining in 8ubeequtnt yttn that were drier. Emtrgenct rnnged from 0 to 6.9% and 0 to 7.1% and surviv81 of emerged seedling8 ranged fkom 6.6 to 5% and 0 to 60% for green and gray rubber rabbitbrush, respectivtly. Survival of green rubber rabbitbrusb was bigbest from mid-spring plantings, but no distinctively favortblt seeding date was found for gray rubber nbbitbrusb. Results suggest that seeds of these shrubs should be planted prior to or during periods wbtn seedbed temperature8 are in tbe 20 to 39 C range and soil moisture is txpttttd near its seasonal bigb. Green rubber rabbitbrush (Chrysorhamnus nuuseosus (PaUas) Britt. subsp. gruveoiens (Nutt.) Piper.) and gray rubber rabbitbrush (Chrysothamnus IuIuseosI(s (Pallas) Britt. subsp. nol(seosI(s (Nutt.) Piper.) are morphologically and ecologically distinct, but sympatric, subspecies that grow on the northern Great Plains. In many areas rabbitbrush is classified as undesirable by range managers. However, green and gray rubber rabbitbrush are important components of rangeland, adding structural and functional diversity. They show potential for use in reclaiming disturbed land by providing cover, stabilizing soils, moderating temperature and moisture regimes, providing forage for mule deer and pronghom, and adding to the aesthetics. Most rabbitbrushes grow rapidly, produce abundant seed, but are not aggressive competitors with herbaceous plants (McArthur et al. 1979). Green rubber rabbitbrush, a large shrub growing to 2m tall, is common on south and southwest slopes of badland plant communities in southeastern Montana (Brown 1971) . This shrub is an early successional species on a wide variety of soil textures on severely disturbed sites including borrow pits, road cuts, and spoil banks of coal and bentonite mines. A smaller shrub, gray rubber rabbitbrush grows to 0.3 to 0.8 m tall. It is limited in its colonizing potential on drastically disturbed sites. Gray rubber rabbitbrush grows mainly on tine textured soils of ridges and slopes in good condition grassland communities
doi:10.2307/3899524 fatcat:nvc3ac3drjbjplqk2g2uqfqb4y