Allelopathy and Exotic Plant Invasion

2010 ◽  
pp. 61-74 ◽  
Author(s):  
Amutha Sampath Kumar ◽  
Harsh P. Bais
Keyword(s):  
Plant Invasion ◽  
Exotic Plant ◽  
Exotic Plant Invasion

Exotic plant invasion and understorey species richness: a comparison of two types of eucalypt woodland in agricultural Western Australia

1998 ◽  
Vol 4 (1) ◽  
pp. 21 ◽  
Author(s):  
Max Abensperg-Traun ◽  
Lyn Atkins ◽  
Richard Hobbs ◽  
Dion Steven
Keyword(s):  
Species Richness ◽  
Exotic Species ◽  
Plant Species ◽  
Plant Invasion ◽  
Native Plants ◽  
Exotic Plants ◽  
Exotic Plant ◽  
Native Plant ◽  
Road Verge ◽  
Exotic Plant Invasion

Exotic plants are a major threat to native plant diversity in Australia yet a generic model of the invasion of Australian ecosystems by exotic species is lacking because invasion levels differ with vegetation/soil type and environmental conditions. This study compared relative differences in exotic species invasion (percent cover, spp. richness) and the species richness of herbaceous native plants in two structurally very similar vegetation types, Gimlet Eucalyptus salubris and Wandoo E. capillosa woodlands in the Western Australian wheatbelt. For each woodland type, plant variables were measured for relatively undisturbed woodlands, woodlands with >30 years of livestock grazing history, and woodlands in road-verges. Grazed and road-verge Gimlet and Wandoo woodlands had significantly higher cover of exotic species, and lower species richness of native plants, compared with undisturbed Gimlet and Wandoo. Exotic plant invasion was significantly greater in Gimlet woodlands for both grazed (mean 78% cover) and road-verge sites (mean 42% cover) than in comparable sites in Wandoo woodlands (grazed sites 25% cover, road-verge sites 19% cover). There was no significant difference in the species richness of exotic plants between Wandoo and Gimlet sites for any of the three situations. Mean site richness of native plants was not significantly different between undisturbed Wandoo and undisturbed Gimlet woodlands. Undisturbed woodlands were significantly richer in plant species than grazed and road-verge woodlands for both woodland types. Grazed and road-verge Wandoo sites were significantly richer in plant species than communities in grazed and road-verge Gimlet. The percent cover of exotics was negatively correlated with total (native) plant species richness for both woodland types (Wandoo r = ?0.70, Gimlet r = ?0.87). Of the total native species recorded in undisturbed Gimlet, 83% and 61% were not recorded in grazed and road-verge Gimlet, respectively. This compared with 40% and 33% for grazed and road-verge Wandoo, respectively. Grazed Wandoo and grazed Gimlet sites had significantly fewer native plant species than did road-verge Wandoo and road-verge Gimlet sites. Ecosystem implications of differential invasions by exotic species, and the effects of grazing (disturbance) and other factors influencing susceptibility to exotic plant invasion (landscape, competition and allelopathy) on native species decline are discussed. Exclusion of livestock and adequate methods of control and prevention of further invasions by exotic plants are essential requirements for the conservation of these woodland systems.

The upland hardwood component of Prince Edward Island's remnant Acadian forest: determination of depth of edge and patterns of exotic plant invasion

2003 ◽  
Vol 81 (11) ◽  
pp. 1113-1128 ◽  
Author(s):  
Kate MacQuarrie ◽  
Christian Lacroix
Keyword(s):  
Exotic Species ◽  
Plant Community ◽  
Plant Invasion ◽  
Vascular Plants ◽  
Canopy Cover ◽  
Percent Cover ◽  
Exotic Plant ◽  
Exotic Plant Invasion ◽  
Acadian Forest ◽  
Study Sites

The upland hardwood component of Prince Edward Island's Acadian forest is among the best remaining examples of the precolonial landscape, but it has been severely fragmented during the past 300 years of human use and settlement. Despite the ecological importance of this remnant habitat and its level of fragmentation, there has been no assessment of depth of edge or exotic plant invasion in these areas. Three 300 m long edge–interior transects were established in each of six study sites. Nine 100-m2 circular plots were sampled along each transect at distances from 5.7 to 300 m; one external plot was established at each transect to sample species in adjacent habitats. In each plot, all vascular plants were identified, a visual estimate of percent cover was made, and soil temperature, canopy cover, and tree diameters were measured. An edge–interior plant community gradient was found within these forests; a plant community characteristic of interior conditions was not reached until a distance of more than 120 m from an edge. This suggests that upland hardwood protected areas smaller than 240 m on a side (5.75 ha) are unlikely to include interior habitat, and sites should be greater than 320 m on all sides (10.24 ha) to ensure at least some interior habitat for vascular plants. Invasion by exotic species was found to be more extensive than that reported from other jurisdictions, and innermost (300 m) plots were not free from exotics. Fifteen exotic species were found within the study sites, with Veronica officinalis (common speedwell) and Hieracium lachenalii (hawkweed) being the most invasive, both in terms of distance penetrated and area covered.Key words: Acadian forest, fragmentation, depth of edge, protected area, Veronica, Hieracium.

EFFECTS OF BIOLOGICAL CONTROL AGENTS AND EXOTIC PLANT INVASION ON DEER MOUSE POPULATIONS

2004 ◽  
Vol 14 (1) ◽  
pp. 241-253 ◽  
Author(s):  
Yvette K. Ortega ◽  
Dean E. Pearson ◽  
Kevin S. McKelvey
Keyword(s):  
Biological Control ◽  
Plant Invasion ◽  
Deer Mouse ◽  
Exotic Plant ◽  
Biological Control Agents ◽  
Exotic Plant Invasion

scholarly journals Environmental factors affecting the success of exotic plant invasion in a wildland-urban ecotone in temperate South America

2019 ◽  
Vol 14 (2) ◽  
pp. 257-274
Author(s):  
Romina Paola Nievas ◽  
Mirian Roxana Calderon ◽  
Marta Matilde Moglia
Keyword(s):  
Soil Moisture ◽  
Environmental Factors ◽  
Environmental Variables ◽  
Anthropogenic Disturbance ◽  
Plant Invasion ◽  
Exotic Plants ◽  
Scaling Analysis ◽  
Exotic Plant ◽  
Factors Affecting ◽  
Exotic Plant Invasion

Urbanization is one of the main causes driving changes in biodiversity patterns and it is regarded as a major threat to native biota. Successful exotic plant invasion depends on invasiveness and invasibility. Invasiveness is related to the characteristics of exotic plants and invasibility to the features of the sites. The objective of this study was to identify the invasibility environmental factors affecting the success of exotic plant invasion in a wildland-urban ecotone of the central region of Argentina (Potrero de los Funes Village, San Luis). Fifty phytosociological inventories were recorded in an area of 700 ha during spring and summer seasons (2013–2015). Abundance-coverage values of plants and environmental variables such as soil characteristics, anthropogenic disturbance, and altitude of the sites were assessed. Soil moisture, electrical conductivity (EC), acidity (pH), organic matter content, and nitrates were determined as part of the soil analysis. A Nonmetric Multidimensional Scaling analysis was used to identify the possible relationship between abundance-coverage of the vegetation and environmental variables. Abundance-coverage of exotic plants was positively influenced by anthropogenic disturbance and nitrate levels, and negatively affected by altitude. However, no significant correlation was found between percentage of exotic plants and pH, EC, or soil moisture. Thus, urbanization and touristic activities influenced the success of exotic plant invasion.

Soil biota and exotic plant invasion

Nature ◽  
2004 ◽  
Vol 427 (6976) ◽  
pp. 731-733 ◽  
Author(s):  
Ragan M. Callaway ◽  
Giles C. Thelen ◽  
Alex Rodriguez ◽  
William E. Holben
Keyword(s):  
Plant Invasion ◽  
Soil Biota ◽  
Exotic Plant ◽  
Exotic Plant Invasion

EXOTIC PLANT INVASION ALTERS NITROGEN DYNAMICS IN AN ARID GRASSLAND

2001 ◽  
Vol 11 (5) ◽  
pp. 1301-1310 ◽  
Author(s):  
R. D. Evans ◽  
R. Rimer ◽  
L. Sperry ◽  
J. Belnap
Keyword(s):  
Plant Invasion ◽  
Nitrogen Dynamics ◽  
Exotic Plant ◽  
Exotic Plant Invasion

scholarly journals Disturbance, Resources, and Exotic Plant Invasion: Gap Size Effects in a Redwood Forest

Madroño ◽  
2010 ◽  
Vol 57 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Brent C. Blair ◽  
Deborah K. Letourneau ◽  
Sara G. Bothwell ◽  
Grey F. Hayes
Keyword(s):  
Size Effects ◽  
Plant Invasion ◽  
Gap Size ◽  
Exotic Plant ◽  
Exotic Plant Invasion ◽  
Redwood Forest
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