Phenotypic Plasticity within the Native Perennial Grass, Poa secunda (Sandberg bluegrass), an Important Component of the Western United States Sagebrush Grassland Vegetation
type: CreativeWork
description: Native plant communities of the Nevada Great Basin are experiencing a rapid shift from native perennial grasses to invasive annual grasses. The ability to respond to competition through root plasticity may be an important trait for survival of native plants in invaded systems. I investigated the following questions about Poa secunda, a common native perennial grass in sagebrush ecosystems: 1) Can P. secunda respond plastically to directly-manipulated nutrient availability? 2) Does P. secunda respond to the presence of B. tectorum? and 3) Are these plastic responses adaptive? For the nutrient experiment, ten seeds from twenty families were sown individually into greenhouse pots, where one P. secunda family is defined as one individual plant. Within each family, five individuals received a low nutrient treatment, and five a high nutrient treatment. Plants were harvested fifty days after emergence. Roots were rinsed, clipped from leaf mass, and digitally scanned. For the competition experiment, twenty seeds from forty-eight families were sown individually into small and large greenhouse pots and one seed of B. tectorum was added to half of the pots. Plants were harvested sixty-seven days after emergence (early harvest), and after one growing season (late harvest) for the competition experiment. Roots were rinsed, clipped from their leaf mass and digitally scanned in a similar manner as the nutrient experiment. For both the nutrient and the competition experiments, measurements included total biomass, root to shoot ratio, leaf number, specific root length (SRL), percent allocation to different root diameter size classes, and plasticity in allocation to these same root diameter classes. In addition change in percent allocation to different root diameter size classes was calculated for plants in response to both low nutrients and competition from B. tectorum. Measures were correlated with plant performance measured as CPI (competitive performance index) and total biomass …
abstract: Native plant communities of the Nevada Great Basin are experiencing a rapid shift from native perennial grasses to invasive annual grasses. The ability to respond to competition through root plasticity may be an important trait for survival of native plants in invaded systems. I investigated the following questions about Poa secunda, a common native perennial grass in sagebrush ecosystems: 1) Can P. secunda respond plastically to directly-manipulated nutrient availability? 2) Does P. secunda respond to the presence of B. tectorum? and 3) Are these plastic responses adaptive? For the nutrient experiment, ten seeds from twenty families were sown individually into greenhouse pots, where one P. secunda family is defined as one individual plant. Within each family, five individuals received a low nutrient treatment, and five a high nutrient treatment. Plants were harvested fifty days after emergence. Roots were rinsed, clipped from leaf mass, and digitally scanned. For the competition experiment, twenty seeds from forty-eight families were sown individually into small and large greenhouse pots and one seed of B. tectorum was added to half of the pots. Plants were harvested sixty-seven days after emergence (early harvest), and after one growing season (late harvest) for the competition experiment. Roots were rinsed, clipped from their leaf mass and digitally scanned in a similar manner as the nutrient experiment. For both the nutrient and the competition experiments, measurements included total biomass, root to shoot ratio, leaf number, specific root length (SRL), percent allocation to different root diameter size classes, and plasticity in allocation to these same root diameter classes. In addition change in percent allocation to different root diameter size classes was calculated for plants in response to both low nutrients and competition from B. tectorum. Measures were correlated with plant performance measured as CPI (competitive performance index) and total biomass …
author: Phillips, Allison J.
keywords: Great Basin, ontogenetic drift, phenotypic plasticity, Poa secunda, restoration, Sandberg bluegrass
date published: 2012
date modified: 2026-07-27T21:46:30Z
provider: University of Nevada - Reno
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Nevada - Reno

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11714/3543