English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Worldwide, exotic invasive grasses have caused numerous ecosystem perturbations. Rangelands of the western USA have experienced increases in the size and frequency of wildfires largely due to invasion by the annual grass Bromus tectorum. Rehabilitation of invaded rangelands is difficult; but long-term success is predicated on establishing healthy and dense perennial grass communities, which suppress B. tectorum. This paper reports on two experiments to increase our understanding of soil factors involved in suppression. Water was not limiting in this study. Growth of B. tectorum in soil conditioned by and competing with the exotic perennial Agropyron cristatum was far less relative to its growth without competition. When competing with A. cristatum, replacing a portion of conditioned soil with fresh soil before sowing of B. tectorum did not significantly increase its growth. The ability of conditioned soil to suppress B. tectorum was lost when it was separated from growing A. cristatum. Soil that suppressed B. tectorum growth was characterized by low mineral nitrogen (N) availability and a high molar ratio of [Formula: see text] in the solution-phase pool of [Formula: see text] Moreover, resin availability of [Formula: see text] explained 66 % of the variability in B. tectorum above-ground mass, attesting to the importance of A. cristatum growth in reducing N availability to B. tectorum. Trials in which B. tectorum was suppressed the most were characterized by very high shoot/root mass ratios and roots that have less root hair growth relative to non-suppressed counterparts, suggesting co-opting of biological soil space by the perennial grass as another suppressive mechanism. Greater understanding of the role of biological soil space could be used to breed and select plant materials with traits that are more suppressive to invasive annual grasses.

Suppression of annual Bromus tectorum by perennial Agropyron cristatum: roles of soil nitrogen availability and biological soil space