Original Articles: Nitrogen Availability and Old-Field Succession in a Shortgrass Steppe

Infrequent composted biosolids applications affect semi-arid grassland soils and vegetation

“…There was also less cover of invasive plant species in the highest application rates (P ¼ 0.0007; data not shown), which is contrary to what is often observed for nutrient addition studies in this region (e.g. Paschke et al, 2000). Another study at this same site demonstrated increases in native perennial grass growth associated with increasing rates of biosolids application (Sullivan et al, 2006).…”

Cottonwood understory zonation and its relation to floodplain stratigraphy

“…Increased N availability may benefit fastgrowing exotics at the expense of slow-growing natives adapted to low resource availability (Chapin 1980). In experimental studies, elevated soil N has been shown to increase the abundance of exotic species (e.g., Brooks 2003; Paschke et al 2000), likely because the flux of unused resources can be exploited by invaders (Davis et al 2000). However, DeCant (2008) argued that N enhancement by Russian olive was unlikely to facilitate exotic plant invasion on the Rio Grande floodplain, because soil microbial growth experiments showed limitation by C, not N. He suggested instead that the effects of shading by Russian olive on PAR and soil moisture may be more responsible for changes in community composition.…”

Seed Bank Depletion: The Key to Long-Term Downy Brome ( Bromus tectorum L.) Management

“…Paschke et al (2000) examined increasing soil carbon through amendments as a mechanism to decrease available soil nitrogen (alter the C:N). Experiments were conducted on the shortgrass steppe of eastern Colorado in early-, mid-, and late-seral plant communities that previously had been cultivated and on one uncultivated site that served as a control.…”

“…This favors its germination, establishment, and dominance on sites. Research has shown that decreasing the amount of available nitrogen (by increasing soil carbon) disfavors downy brome (McClendon and Redente 1991;Paschke et al 2000). There currently are no practical methods commercially available to increase soil carbon thus, decrease available nitrogen.…”