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ARS Home » Pacific West Area » Logan, Utah » Forage and Range Research » Research » Research Project #438918

Research Project: Wildland Testing of Bluebunch Wheatgrass Plant Materials Under Variable Environmental Conditions

Location: Forage and Range Research

Project Number: 2080-21000-018-36-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 30, 2020
End Date: Sep 30, 2022

Objective:
Wildland-test the performance of a broad array of bluebunch wheatgrass (BBWG) materials in response to biotic and abiotic filters that strongly influence rangeland restoration efforts. Assessing plant material performance across a range of climates, soils, and biotic conditions will specifically test how phenotypic plasticity of key plant traits contribute to seedling establishment and survival. In wildland settings, enhance plant material testing by comparing trait expression among narrow and broad plasticity variants under investigation by the USDA, Agricultural Research Service (ARS) and compare them to local BBWG populations using a reciprocal-planting experimental design.

Approach:
The performance of 12 BBWG materials: 6 originating from current ARS experiments (e.g., narrow and broad phenotypic plasticity variants of P-7, Anatone, and Columbia) and 6 collected from widely representative ecological sites in northern Utah will be tested in each of three seed transfer zones, and within each seed zone across two ecological sites where BBWG is the most prominent herbaceous species. Ecological sites sites will include Semidesert Gravelly Loam (coarse soil texture) and Semidesert Loam (fine soil texture). At each of these six sites, plant materials will be seeded or transplanted into paired plots arranged along 5 replicated linear transects (blocks; n = 5). Seeded portions will consist of sowing seeds at a rate of 2.5 kg/ha pure live seed into three 50 cm rows (spaced 25 cm), and the transplant portions will consist of 9 plants placed in a 3 x 3 grid (spaced 25cm apart). In addition, paired plots will be placed in one of two different microsites (under sagebrush canopy or in interspaces between sagebrush plants). Thus, each site will contain a total of 120 paired plots (5 reps x 12 BBWG materials x 2 microsites). Beginning in the year after establishing plots, simulated herbivory will be applied to select plants in each paired plot by removing an estimated 50% of biomass by weight each spring. Performance of BBWG will be evaluated by applying demographic models and multivariate path analysis models to a core set of plant traits; including the following: percentage establishment, survival rate, reproductive output (tillering rate and spike number), leaf water stress (stomatal conductance), root length density, defoliation recover (re-growth following clipping treatments), and annual biomass production (collected at end of each growing season.