First-Year Establishment, Biomass and Seed Production of Early vs. Late Seral Natives in Two Medusahead (Taeniatherum caput-medusae) Invaded Soils

Abstract

Re-seeding efforts to restore or rehabilitate Great Basin rangelands invaded by exotic annual grasses are expensive and have generally achieved limited success. There is a need to identify new strategies to improve restoration outcomes. We tested the performance of a native early seral seed mix (annual forbs, early seral grasses and shrubs) with that of a native late seral mix representative of species commonly used in restoration when growing with medusahead in soils of contrasting texture (sandy loam and clay loam) through the first growing season after seeding. Natives were also seeded without medusahead. We found that the grasses and forbs in the early seral mix established significantly better than those in the late seral mix, and the early seral mix significantly reduced aboveground biomass and seed production of medusahead by 16 and 17% respectively, likely because of competition with the early seral native forb, bristly fiddleneck. Medusahead performance was reduced in both soil types, suggesting utility of bristly fiddleneck in restoration is not limited to only one soil type. In contrast, the late seral mix did not suppress medusahead establishment, aboveground biomass or seed production. Although the native perennial grasses, particularly early seral species, were able to establish with medusahead, these grasses did not appear to have a suppressive effect on medusahead during the first growing season. Medusahead was able to establish and produce seeds on both soil types, demonstrating an ability to expand its current range in the Intermountain West, though aboveground biomass and seed production was higher in the clay loam. Our results suggest that certain species may play a key role in restoration, and that targeting early seral species in particular to find additional native species with the ability to suppress exotic annual grasses is an important next step in improving restoration outcomes in desert ecosystems.

Seed Source May Determine Field‐Specific Germination and Emergence: The Source by Planting Environment Interaction

“…Most of the detailed demographic work on establishment of perennial grasses in the United States has been performed in the Great Basin and Intermountain West. Other researchers have observed native grass establishment rates of 17 to 75% (Uselman et al, 2014) in small experimental plots, and high germination (as much as 79%) followed by low emergence (4 to 17%) in post‐fire plots (James et al, 2011; James and Svejcar, 2010). Fire may lead to seed bed environments that are particularly inhospitable, with low establishment rates—another study found establishment rates to be as low as 0.75% in post‐fire soils (Madsen et al, 2012).…”

Emergence and early survival of early versus late seral species in Great Basin restoration in two different soil types

“…During the study period, soil volumetric water content (0–12 cm) was 8.3 ± 0.3% and 18.3 ± 0.8% in mid‐Nov, 24.0 ± 0% and 34.5 ± 2.5% in late Dec, and 7.7 ± 0.3% and 20.0 ± 0.6% by late May in the sandy loam and clay loam, respectively (Uselman et al. ). In the sandy loam, the average annual soil temperature was 13.2 °C, varying between −1.4 °C in Dec and 29.7 °C in Jul at 1 cm (data not shown).…”

“…However, in our companion study, we showed that T. caput‐medusae can also be highly successful in a more coarse‐textured soil, but we did not evaluate emergence or survival during early life stages (Uselman et al. ). In contrast, B. tectorum is able to grow in most soil types, but it is especially successful on coarse‐textured loamy soils, including sandy loams commonly occupied by big sagebrush (Young ; Welch ).…”

“…In our companion study, we reported biomass production, seed production and first‐year establishment data (Uselman et al. ). In this study, we present a detailed examination of emergence, timing of emergence and early seedling performance because early life stages (i.e.…”

Managing Medusahead (Taeniatherum caput-medusae) on Rangeland: A Meta-Analysis of Control Effects and Assessment of Stakeholder Needs

“…The majority of the grazing studies in our meta-analysis attempted ket services (Kyser et al, 2013;Davies et al, 2014;Uselman et al, 2014).…”