Wide Ecological Amplitude of a Diversity-Reducing Invasive Grass

Abstract

The goals of this study were to identify habitats occupied by the Eurasian grass Bothriochloa ischaemum (King Ranch bluestem) on the eastern Edwards Plateau of central Texas, USA, and to measure the effects of this invasive species on plant diversity. A set of descriptive field studies were conducted to determine the relationships between habitat characteristics (woody cover, slope, presence of roads and trails, history of prescribed burning, and presence of grazing) and the presence and abundance of this species. Species richness and diversity of perennial herbaceous species were compared between plots in which B. ischaemum was absent and plots that it dominated.The only habitat in which B. ischaemum was never found was under the canopies of woody plants. B. ischaemum grew in plots of all inclinations (flat sites to steep hillsides), with little evidence of habitat preference. B. ischaemum was more often, although not exclusively, found in plots near roads, probably because roads facilitate seed dispersal. There was no significant relationship between either grazing or fire history and the distribution of this species. B. ischaemumdominated plots had lower species diversity and species richness than plots in which no B. ischaemum was found. The results of this study confirm that B. ischaemum is very common on the eastern Edwards Plateau and suggest that it will continue to spread throughout this region and to reduce native herbaceous plant diversity there.

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

“…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.…”

Patterns of spatial genetic structure and diversity at the onset of a rapid range expansion: colonisation of the UK by the small red-eyed damselfly Erythromma viridulum

“…In particular, climate change and its associated consequences (such as changes in habitat) has been associated with P. C. Watts (&) Á S. Keat Á D. J. Thompson School of Biological Sciences, University of Liverpool, The Biosciences Building, Crown Street, Liverpool L69 7ZB, UK e-mail: p.c.watts@liv.ac.uk altered geographic ranges in many insect species (Parmesan and Yohe 2003). Irrespective of the specific underlying mechanisms, rapid shifts in distribution are expected for taxa with good dispersal capabilities (Pearson and Dawson 2003), with such changes in distributions likely impacting on current patterns of biodiversity; for example, taxa that exploit new environments may reduce the niche space of native species and/or alter ecosystem function (Sakai et al 2001;Gabbard and Fowler 2007). An essential part of biodiversity conservation, therefore, is to identify the evolutionary patterns and processes that are associated with successful colonisation (Pérez et al 2006).…”

Incipient invasion of Galenia secunda Sond. (Aizoaceae) in Southern Spain

“…G. secunda was more often found near roads (0-25 m) (Fig. 3d), because roads facilitate seed dispersal (Gabbard and Fowler 2007). From the net area of locations found, an area of occupancy of 91.9 ha and an extent of occurrence (not including aquatic environments) of 14,250 ha were calculated, thus suggesting an early stage of invasion.…”