Competitive abilities of native grasses and non-native (Bothriochloa spp.) grasses

Abstract

Old World Bluestems (OWB), introduced from Europe and Asia in the 1920s, recently have begun to raise concerns in the Great Plains. Despite suggestion in the late 1950s that OWB were weedy and negatively impacted biological diversity, they were widely introduced throughout the Great Plains for agricultural purposes. Anecdotal evidence suggests that OWB exhibit invasive characteristics that promote competitive exclusion of native species. The objective of our study was to quantify the competitive abilities of two OWB species (Caucasian bluestem; Bothriochloa bladhii (Retz.) S.T. Blake (= Bothriochloa caucasica (Trin.) C.E. Hubb.) and yellow bluestem; Bothriochloa ischaemum (L.) Keng) with three native grass species (big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachyrium scoparium (Michx.) Nash), and sideoats grama (Bouteloua curtipendula (Michx.) Torr.)). A greenhouse target-neighbor study was conducted to assess both interspecific and intraspecific competition. A total of 480 pots (4.4 l) filled with native soil was used with all pair-wise combinations of species and four density treatments (six replications). Vegetative tiller height, above-and belowground biomass were measured at the end of 16 weeks. Both of the OWB significantly inhibited at least one growth parameter of the three native grass species, while most of the native species did not inhibit growth of either OWB species. Growth of B. ischaemum was enhanced when grown in association with S. scoparium. Based upon the results of our study of OWB competitive superiority and previous research, many of the characteristics possessed by OWB are found to be in common with known invasive species. Hence, we propose that two OWB are competitively superior to three common native prairie species providing them with the ability to invade and threaten the native grasslands of the Central and Southern Great Plains.

Effects of Planting Method on Enhanced Stand Establishment and Subsequent Performance of Forage Native Warm-Season Grasses

“…In the seeded plots, values were still the least for BB (9 cm), but not statistically different from GG (11) and all other differences were only numeric (P > .05). Specific differences in basal diameter could result from variable competitive abilities of the native grass species against the already established weeds similar to earlier observations (Schmidt et al, 2008). While the current data still indicate that transplanting may be a better establishment method to direct seeding for the NWSGs, results further showed that upon successful establishment, GG will produce a thicker stand relatively sooner while BB may suffer weed competition longer.…”

Grazed Pannonian grassland beta-diversity changes due to C4 yellow bluestem

“…It shows the stochastic processes of filtereffects resulting in low diversity. Experimental evidences confirm the competitive superiority of Bothriochloa ishaemum [21]. There are several traits (e.g.…”

“…There are several traits (e.g. bunchgrass architecture; reproduction by rhizomes, stolons, and seeds via apomixis; small seed sizes; good dispersal ability; very plastic morphological traits; rapid growth to sexual maturity) that explain the competitive advantage of Bothriochloa ishaemum [21,[54][55][56][57].…”

“…On the other hand overgrazing and improper management can lead to the spread of C 3 grasses for example Brachypodium genuense [17,18]. Yellow bluestem as a typical C 4 grass appears invasive in several part of the world reducing biodiversity [19][20][21] and the economic value of grasslands [22]. Therefore, it is important to study and understand the patterns and mechanisms that regulate the spread of yellow bluestem and to recognize the related changes in plant community structures.…”

Yield, Yield Distribution, and Forage Quality of Warm-Season Perennial Grasses Grown for Pasture or Biofuel in the Southern Great Plains

“…"Plains" old world bluestem (Bothriochloa ishaemum) was released in 1972 by the Oklahoma Agricultural Experiment Station and USDA-ARS from lines originating in southcentral Asia. It is a bunchgrass with good drought tolerance [13], but it is an aggressive competitor with indigenous grass species [14]. "Pensacola" bahiagrass (Paspalum notatum) was introduced into the US from South America in the late 1930s and is the most widely grown bahiagrass in the US.…”