Influence of a native legume on soil N and plant response following prescribed fire in sagebrush steppe

Abstract

Abstract. Woodland expansion affects grasslands and shrublands on a global scale. Prescribed fire is a potential restoration tool, but recovery depends on nutrient availability and species responses after burning. Fire often leads to longterm losses in total nitrogen, but presence of native legumes can influence recovery through addition of fixed nitrogen. We examined the effects of prescribed fire in the central Great Basin, Nevada, USA, on density, biomass and nutrient content of a native legume, Lupinus argenteus (Pursh), and the effects of Lupinus presence and prescribed fire on soil inorganic nitrogen and on neighboring plant functional groups. We examined three treatments -1 year post-burn, 3 years post-burn and unburned control in three replicate blocks. Extractable soil inorganic nitrogen was variable and, despite a tendency towards increased inorganic nitrogen 1 year post-burn, differences among treatments were not significant. Extractable soil inorganic nitrogen was higher in Lupinus presence regardless of time since fire. Lupinus density increased after fire mainly owing to increased seedling numbers 3 years post-burn. Fire did not affect Lupinus tissue N and P concentrations, but cover of perennial grasses and forbs was higher in Lupinus presence. The invasive annual grass Bromus tectorum had low abundance and was unaffected by treatments. Results indicate that Lupinus has the potential to influence succession through modification of the post-fire environment.

Extent of Kentucky Bluegrass and Its Effect on Native Plant Species Diversity and Ecosystem Services in the Northern Great Plains of the United States

“…The mixed-grass prairie of the Northern Great Plains developed under the influence of multiple disturbances, such as fire and grazing (e.g., Bowman et al 2009;Coppedge 1998). In native, mixed-grass prairie sites, available nitrogen is sequestered in belowground organic matter, and intense prairie fires reduced available nitrogen through volatilization and transfer of organic N from labile to recalcitrant pools (Goergen and Chambers 2009). Additionally, most native grasses and forbs exhibit high carbon : low nitrogen ratios further delaying breakdown and reducing available nitrogen for plant growth.…”

Drought sensitivity of an N2‐fixing tree may slow temperate deciduous forest recovery from disturbance

“…Disturbance events in forests are often accompanied by large losses of N, such as the removal of tree biomass during harvesting and leaching of dissolved inorganic N due to reduced uptake by trees (Knoepp and Swank 1997, Menge et al 2009b, Boring et al 2014, McLauchlan et al 2014. This process results in soils with locally elevated N mineralization and nitrification rates (Montagnini et al 1986) and inorganic N availability (Goergen and Chambers 2009), which may facilitate the growth of neighboring nonfixers (DeBell et al 1997). This process results in soils with locally elevated N mineralization and nitrification rates (Montagnini et al 1986) and inorganic N availability (Goergen and Chambers 2009), which may facilitate the growth of neighboring nonfixers (DeBell et al 1997).…”

Sagebrush steppe recovery after fire varies by development phase of Juniperus occidentalis woodland

“…Nitrogen fixing plants, such as Lupinus argenteus, Pursh (silvery lupine), have the potential to influence plant succession in A. t. ssp. vaseyana steppe by modifying post-fire N availability (Goergen and Chambers 2009). However, B. tectorum cover did not appear to be greater in the presence of C. velutinus, hence we concluded that the lack of perennial herbaceous vegetation on the Phase 3 sites allowed post-fire B. tectorum dominance.…”