Event Title

Biological Soil Crust Effect on Restoration Grasses and Forbs Establishment Under Different Restoration Seeding Methodswhen Drilled, Minimum Till Drilled, and Broastcast

Presenter Information

Hilary Whitcomb

Location

USU Eccles Conference Center

Event Website

http://www.restoringthewest.org/

Abstract

Biological soil crusts (BSC) are an important ecological component of post-wildfire restorations. They can be classified into narrow or broad successional groups that have different impacts on plant available water, nutrients, and seed penetration. However, BSC successional groups have been poorly studied in semi-arid Great Basin restoration projects. We designed a greenhouse study to determine seed drilling interaction with five BSC groups (very little crust development [M1], early cyanobacteria [M2], mid-cyanobacteria [M3], diverse moss/lichen [M4], and tall-moss mats found predominantly under shrubs [M5]) on the invasive cheatgrass Bromus tectorum and common restoration species (bluebunch wheatgrass Pseudoroegneria spicata, bottlebrush squirreltail Elymus elymoides, needle-and-thread grass Hesperostipa comata, indian ricegrass Achnatherum hymenoides, western yarrow Acchilea millefolium L. var. occidentalis, and gooseberry globemallow Sphaeralcea grossulariifolia). Two pots of each group were range or minimum-till “drilled” 32 (using an auger) or broadcast, then singed with a heat lamp to simulate a light burn. BSC development and seeding treatment had significant effects on plant germination and fitness. Intact crust decreased cheatgrass germination while drilling improved its germination and fitness. Minimum-till drilling generally supported the best germination and fitness in all species. Range drilling and broadcast seeding were often surprisingly similar in their effect on grasses. Germination and fitness for both forbs were greater when broadcast compared to range drilling. More developed BSC supported greater germination and fitness across native species. Tall-moss often supported the fittest plants, but tended to have lower germination rates. Minimum-till drilling often resulted in lessened BSC group effect (e.g. no height difference in M2-M4) while range drilling tended to accentuate BSC group effects (e.g. taller plants with more developed BSC). Overall this study suggests interaction between BSC and seeding type may result in different outcomes for common restoration species. Field studies are recommended.

Comments

Hilary Whitcomb is a PhD student at Utah State University, Ecology Center, Department of Environment and Society

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Oct 29th, 1:30 PM Oct 29th, 2:00 PM

Biological Soil Crust Effect on Restoration Grasses and Forbs Establishment Under Different Restoration Seeding Methodswhen Drilled, Minimum Till Drilled, and Broastcast

USU Eccles Conference Center

Biological soil crusts (BSC) are an important ecological component of post-wildfire restorations. They can be classified into narrow or broad successional groups that have different impacts on plant available water, nutrients, and seed penetration. However, BSC successional groups have been poorly studied in semi-arid Great Basin restoration projects. We designed a greenhouse study to determine seed drilling interaction with five BSC groups (very little crust development [M1], early cyanobacteria [M2], mid-cyanobacteria [M3], diverse moss/lichen [M4], and tall-moss mats found predominantly under shrubs [M5]) on the invasive cheatgrass Bromus tectorum and common restoration species (bluebunch wheatgrass Pseudoroegneria spicata, bottlebrush squirreltail Elymus elymoides, needle-and-thread grass Hesperostipa comata, indian ricegrass Achnatherum hymenoides, western yarrow Acchilea millefolium L. var. occidentalis, and gooseberry globemallow Sphaeralcea grossulariifolia). Two pots of each group were range or minimum-till “drilled” 32 (using an auger) or broadcast, then singed with a heat lamp to simulate a light burn. BSC development and seeding treatment had significant effects on plant germination and fitness. Intact crust decreased cheatgrass germination while drilling improved its germination and fitness. Minimum-till drilling generally supported the best germination and fitness in all species. Range drilling and broadcast seeding were often surprisingly similar in their effect on grasses. Germination and fitness for both forbs were greater when broadcast compared to range drilling. More developed BSC supported greater germination and fitness across native species. Tall-moss often supported the fittest plants, but tended to have lower germination rates. Minimum-till drilling often resulted in lessened BSC group effect (e.g. no height difference in M2-M4) while range drilling tended to accentuate BSC group effects (e.g. taller plants with more developed BSC). Overall this study suggests interaction between BSC and seeding type may result in different outcomes for common restoration species. Field studies are recommended.

http://digitalcommons.usu.edu/rtw/2015/Posters/2