Seeding emergence patterns of six restoration species in soils from two big sagebrush plant communities

Authors: WILDER, LACEY - Utah State University; VEBLEN, KARI - Utah State University; SCHUPP, EUGENE - Utah State University; Monaco, Thomas

Submitted to: Western North American Naturalist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2018
Publication Date: 6/30/2019
Citation: Wilder, L., Veblen, K.E., Schupp, E.W., Monaco, T.A. 2019. Seeding emergence patterns of six restoration species in soils from two big sagebrush plant communities. Western North American Naturalist. 79(2):233-246. https://doi.org/10.2135/cropsci2017.11.0689.
DOI: https://doi.org/10.2135/cropsci2017.11.0689

Interpretive Summary: The influence of soil properties on emergence of seeded species to improve degraded herbaceous understory conditions in shrubland plant communities is largely unexplored. We evaluated emergence patterns of six commonly seeded restoration species in soils from Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) and mountain big sagebrush (A. t. ssp. vaseyana [Rydb.] Beetle) plant communities that differed in soil texture, soil organic matter content, and soil water holding capacities. We conducted two separate experiments that regularly wetted soils to standardized soil water potentials (i.e., field capacity; -0.03 MPa) and allowed differences in evaporation to create distinct wet-dry watering pattern cycles over a 26-29 d period. We hypothesized that greater water holding capacity of vaseyana soil would result in higher emergence than in wyomingensis soil, and that this pattern would be more pronounced under low soil water content due to lower evaporation in vaseyana soils. Results supported our assumption that differences in soil texture and organic matter between soils translate into fundamental differences in soil water holding capacity: finer-textured vaseyana soils held roughly two-fold more water than coarse-textured wyomingensis soils. On the other hand, seeds in vaseyana soils were exposed to fewer frequent wet-dry cycles compared to wyomingensis soils. Although restoration species collectively exhibited greater emergence in vaseyana than wyomingensis soil, patterns were vastly different among species and differences between soils became more pronounced under low soil water for only two species. Consequently, both hypotheses were rejected due to variable responses among species. We conclude that the manner in which soils and water uniquely influenced emergence patterns provides new insights into species suitability for restoration sites and how inherent soil differences may constrain seeding success.

Technical Abstract: The influence of soil properties on emergence of seeded species to improve degraded herbaceous understory conditions in shrubland plant communities is largey unexplored. We evaluated emergence patterns of six commonly seeded restoration species in soils from Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) and mountain big sagbrush (A. t. ssp. vaseyana [Rydb.] Beetle) plant communities that differed in soil texture, soil organic matter content, and soil water holding capacities. We conducted two separate experiments that regularly wetted soils to standardized soil water potentials (i.e., field capacity; -0.03 MPa) and allowed differences in evaporation to create distinct wet-dry watering pattern cycles over a 26-29 d period. We hypothesized that greater water holding capacity of vaseyana soil would result in higher emergence than in wyomingensis soil, and that this pattern would be more pronounced under low soil water content due to lower evaporation in vaseyana soils. Results supported our assumption that differences in soil texture and organic matter between soils translate into fundamental differences in soil water holding capacity: finer-textured vaseyana soils held roughly two-fold more water than coarse-textured wyomingensis soils. On the other hand, seeds in vaseyana soils were exposed to fewer frequent wet-dry cycles compared to wyomingensis soils. Although restoration species collectively exhibited greater emergence in vaseyana than wyomingensis soil, patterns were vastly different among species and differences between soils became more pronounced under low soil water for only two species. Consequently, both hypotheses were rejected due to variable responses among species. We conclude that the manner in which soils and water uniquely influenced emergence patterns provides new insights into species suitability for restoration sites and how inherent soil difference may constrain seeding success.