Using native annual plants to restore post-fire habitats in western North America

Abstract

Increasing fire frequencies and uncharacteristic severe fires have created a need for improved restoration methods across rangelands in western North America. Traditional restoration seed mixtures of native perennial mid- to late-seral plant species may not be suitable for intensely burned sites that have been returned to an early-seral condition. Under such conditions, native annual plant species are likely to be more successful at becoming established and competing with exotic annual plant species, such as Bromus tectorum L., for resources. We used a field study in Colorado and Idaho, USA, to test the hypothesis that native annual plant species are better suited to post-fire restoration efforts compared with perennial plant species that are commonly used in traditional seed mixtures. Replicated test plots at three post-fire sites were assigned one of four treatments: (1) native annual seed mixture, (2) standard perennial seed mixture, (3) combination of annual and perennial and (4) an unseeded control. Seeding native annuals with perennials resulted in a slight reduction in exotic plant cover, suggesting that it is potentially beneficial to include native annual plant species in restoration seed mixtures.

Fuel Reduction, Seeding, and Vegetation in a Juniper Woodland

“…Limiting similarity theory predicts that plant communities are able to better resist invasion when resident species are more similar to potential invaders (Emery 2007). Our data also support recent evidence that early successional forbs can be successful as seeded species in preventing exotic invasions (Abella et al 2012;Herron et al 2013). Moreover, propagule supply for the tall annual exotic group of species was probably relatively low in the study area prior to cutting.…”

Using revegetation to suppress invasive plants in grasslands and forests

“…The small number of studies we identified and the diverse methods and metrics used within those studies prevent us from conducting a robust meta‐analysis. However, studies that supported the efficacy of revegetation reported IPS cover or biomass to be reduced 11%–94% by revegetation (Blumenthal, Jordan, & Svenson, ; Herron, Jonas, Meiman, & Paschke, ). Although it is important to consider these responses within the context of potential positive‐outcome publication bias (Fanelli, ), this wide range emphasizes that the results of restoration efforts may be context dependent and that there is a need to identify which conditions maximize the ability of revegetation to suppress IPS.…”

“…The small number of studies we identified and the diverse methods and metrics used within those studies prevent us from conducting a robust meta-analysis. However, studies that supported the efficacy of revegetation reported IPS cover or biomass to be reduced 11%-94% by revegetation (Blumenthal, Jordan, & Svenson, 2003;Herron, Jonas, Meiman, & Paschke, 2013).…”

The role of resource limitation in restoration of sagebrush ecosystems dominated by cheatgrass (Bromus tectorum)

“…Also, they may decrease growth and reproduction of invasive annual grasses via competitive interactions. An effective, integrated restoration approach for improving establishment of native species involves seeding nonnative annuals such as common wheat (Triticum aestivum) that can serve as cover crops and reduce success of non-native invasive annuals in the first year, and then seeding native species in the following year (Koscelny et al 1990, Monaco et al 2003, Herron et al 2013. Because species like common wheat are typically sterile, competition from these species in the second year and the risk that they will reproduce and become invasive is nil.…”