Abstract Detail

Ecophysiology

Fulton , Mary Jane [1], Hildebrand, Terri [2].

Anatomical Root Plasticity in an Invasive Plant Species (Salsola tragus, Amaranthaceae) Growing on Varying Substrates.

Invasive plant species often exhibit advantages over native species.  These species usually display rapid growth and especially high tolerances to environmental stress, or phenotypic plasticity.  Invading plant populations present an immediate ecological concern to native communities and species because invaders evolve rapidly in response to biotic and abiotic factors.  Members of Salsola L. (Amaranthaceae) are native to the Ural Mountains of Russia but, upon their introduction, spread across North America in less than 30 years. Our research first explored the effects of climate and substrates (sand or clay) on S. tragus plants growing in southern Utah.  Root samples were collected from soil types that occurred in low, dry Mohave Desert climates (990 m, 33 cm) as well as sand and clay soils at higher elevations and precipitation (1800 m, 87 cm).  Root cross-sections showed vascular tissue layers that occurred in repeated defined rings of fibers, xylem and phloem outward from a central stele. Measurements of fiber, xylem, and phloem bands in addition to vessel members revealed a significant difference among roots that developed in the sand and clay soils (p < 0.001), but no effect of climate or elevation on root anatomical plasticity in S. tragus.  Although sand and clay soils differ in their ability to retain water, we further hypothesized that the abrasive nature of sifting sandy soils had a primary effect on root structure, resulting in the increase in fiber layers observed in plants collected from the sandy soils. To test this hypothesis, we used a common garden greenhouse experiment that controlled for soil water levels regardless of substrate type.  We germinated S. tragus plants and transplanted them into soilless mix (control), sand and clay soils in 15 cm pots in a controlled greenhouse environment.  Half of the pots received six minutes of vibration at 250 rpms when soil moisture levels in the pot registered below a predetermined level (1 dS/m). After 75 days, plants were removed from pots, above- and belowground biomass determined, and overall height and width of plants recorded.  Cross-sections were prepared at identical measurements on all roots and stained (safranin) to visualize vascular components and fibers. Analyses are on-going and results will be presented.

1 - Southern Utah University, Department of Biology, 351 West University Boulevard, Cedar City, UT, 84720, USA
2 - Sweetgrass Consulting, 1223 West Cedar Knolls South, Cedar City, Utah , 84720, USA

Keywords:
exotic species
species management
species distribution.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Eyrie/Boise Centre
Date: Monday, July 28th, 2014
Time: 5:30 PM
Number: PEP009
Abstract ID:794
Candidate for Awards:Physiological Section Best poster presentation,Physiological Section Physiological Section Li-COR Prize