The Competitive Response of Panicum virgatum Cultivars to Non-Native Invasive Species

Abstract

It is important to use the most appropriate plant cultivar in restoration or biofuel trials especially when plantings are likely to be invaded by undesirable species. In this study, the competitive response of two lowland and three upland cultivars of the dominant C 4 grass Panicum virgatum to three invasive species (Bromus inermis, Schedonorus phoenix, and Poa pratensis) was tested using a simple pair-wise greenhouse experiment. Response variables (height, number of leaves, tiller density, and biomass of P. virgatum) and resources (soil moisture and light intensity) were measured over a seven-month period. Performance of the different P. virgatum cultivars were differentially reduced by the three invasive species, especially the performance of the Kanlow (lowland) and Blackwell (upland) cultivars. Low soil moisture reduced the performance of P. virgatum in the presence of only one invasive (Bromus inermis) irrespective of cultivar source. Root, shoot, and total biomass depended on cultivar and did not show an interaction with invasive species identity. The results of this greenhouse study suggest that the P. virgatum cultivars differentially responded to the invasive species and that the cultivar used should be considered carefully in planning prairie restorations or biofuel trials in the context of likely invasive species.

Trigonelline Accumulation in Leaves of Panicum virgatum Seedlings

“…The units differ between the two experiments because Cho et al [4] used a pure sample to determine TRG availability; in this study a pure sample was not used to determine the availability of TRG. However, a previous study showed a significant interaction between P. virgatum cultivar and moisture level that had a TRG concentration range of 0.1-1.1 OD 264 gFW -1 [18]. In this experiment, cultivar source did not significantly affect TRG concentration.…”

“…Restoration is necessary to restore the highly degraded and frequently arid prairie ecosystem [22] and success may depend on successful establishment of the dominant plants, such as P. virgatum, in drought stressed soil [15]. Invasive species also pose a threat to the establishment of P. virgatum and can utilize the available resources [23]. Therefore, knowledge of the effect of soil moisture levels on cultivars may be important in making an informed selection and the response of P. virgatum and other dominant grasses should be considered as a potential filter in tallgrass prairie for restoration.…”

Response of bluebunch wheatgrass to invasion: Differences in competitive ability among invader‐experienced and invader‐naïve populations

“…There is some evidence that cultivars may be more competitive against invasive weeds than are local ecotypes, largely due to their increased biomass production (Lesica & Atthowe, ). However, this may not be true for all cultivars as competitiveness against invasive species is not an explicit selection criterion during breeding (Shwartz, ). Understanding the potential benefits of cultivars in terms of increased competitiveness in highly invaded areas is critical in determining when their use is appropriate, given concerns that they reduce genetic diversity and result in a loss of locally adapted genotypes in their wild progenitors (Schroder & Prasse, , ).…”

“…There is some evidence that cultivars may be more competitive against invasive weeds than are local ecotypes, largely due to their increased biomass production (Lesica & Atthowe, 2007). However, this may not be true for all cultivars as competitiveness against invasive species is not an explicit selection criterion during breeding (Shwartz, 2011). Understanding the potential benefits of cultivars in terms of should be driven by the element of competitive ability (either tolerance or suppression) that is most important to project goals.…”