Akasha M. Faist Armin J. Howell Sasha C. Reed Scott Ferrenberg 2018 <p><strong>Background and aims</strong></p><p>Biocrusts are communities of cyanobacteria, mosses, and/or lichens found in drylands worldwide. Biocrusts are proposed to enhance soil fertility and productivity, but simultaneously act as a barrier to the invasive grass, <i>Bromus tectorum</i>, in western North America. Both biocrusts and <i>B. tectorum</i> are sensitive to climate change drivers, yet how their responses might interact to affect dryland ecosystems is unclear.</p><p><strong>Methods</strong></p><p>Using mesocosms with bare soil versus biocrust cover, we germinated <i>B. tectorum</i> seeds collected from warmed, warmed + watered, and ambient temperature plots within a long-term climate change experiment on the Colorado Plateau, USA. We characterized biocrust influences on soil fertility and grass germination, morphology, and chemistry.</p><p><strong>Results</strong></p><p>Biocrusts increased soil fertility and <i>B. tectorum</i> biomass, specific leaf area (SLA), and root:shoot ratios. Germination rates were unaffected by mesocosm cover-type. Biocrusts delayed germination timing while also interacting with the warmed treatment to advance, and with the warmed + watered treatment to delay germination.</p><p><strong>Conclusions</strong></p><p>Biocrusts promoted <i>B. tectorum</i> growth, likely through positive influence on soil fertility which was elevated in biocrust mesocosms, and interacted with seed treatment-provenance to affect germination. Understanding how anticipated losses of biocrusts will affect invasion dynamics will require further investigation of how plant plasticity/adaptation to specific climate drivers interact with soil and biocrust properties.</p> application/pdf 10.1007/s11104-017-3525-1 en Springer Biocrusts enhance soil fertility and Bromus tectorum growth, and interact with warming to influence germination article