scholarly journals The unseen invaders: introduced earthworms as drivers of change in plant communities in North American forests (a meta-analysis)

2016 ◽  
Vol 23 (3) ◽  
pp. 1065-1074 ◽  
Author(s):  
Dylan Craven ◽  
Madhav P. Thakur ◽  
Erin K. Cameron ◽  
Lee E. Frelich ◽  
Robin Beauséjour ◽  
...  
2006 ◽  
Vol 128 (4) ◽  
pp. 467-474 ◽  
Author(s):  
Christopher B. Anderson ◽  
Clayton R. Griffith ◽  
Amy D. Rosemond ◽  
Ricardo Rozzi ◽  
Orlando Dollenz

2018 ◽  
Vol 115 (24) ◽  
pp. 6237-6242 ◽  
Author(s):  
Shihong Jia ◽  
Xugao Wang ◽  
Zuoqiang Yuan ◽  
Fei Lin ◽  
Ji Ye ◽  
...  

The theory of “top-down” ecological regulation predicts that herbivory suppresses plant abundance, biomass, and survival but increases diversity through the disproportionate consumption of dominant species, which inhibits competitive exclusion. To date, these outcomes have been clear in aquatic ecosystems but not on land. We explicate this discrepancy using a meta-analysis of experimental results from 123 native animal exclusions in natural terrestrial ecosystems (623 pairwise comparisons). Consistent with top-down predictions, we found that herbivores significantly reduced plant abundance, biomass, survival, and reproduction (allP< 0.01) and increased species evenness but not richness (P= 0.06 andP= 0.59, respectively). However, when examining patterns in the strength of top-down effects, with few exceptions, we were unable to detect significantly different effect sizes among biomes, based on local site characteristics (climate or productivity) or study characteristics (study duration or exclosure size). The positive effects on diversity were only significant in studies excluding large animals or located in temperate grasslands. The results demonstrate that top-down regulation by herbivores is a pervasive process shaping terrestrial plant communities at the global scale, but its strength is highly site specific and not predicted by basic site conditions. We suggest that including herbivore densities as a covariate in future exclosure studies will facilitate the discovery of unresolved macroecology trends in the strength of herbivore–plant interactions.


PLoS ONE ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. e0168613 ◽  
Author(s):  
Lisa A. Waddell ◽  
Judy Greig ◽  
Mariola Mascarenhas ◽  
Shannon Harding ◽  
Robbin Lindsay ◽  
...  

2009 ◽  
Vol 2 (3) ◽  
pp. 253-259 ◽  
Author(s):  
Don Cipollini ◽  
Stephanie Enright

AbstractWhen exposed to native or introduced herbivores and pathogens, invasive plants may become weaker competitors with more benign impacts on individual plants and plant communities. In a greenhouse pot study, we tested whether the presence of powdery mildew disease caused by Erysiphe cruciferarum could alter the competitive impact of garlic mustard on Impatiens pallida, a North American native understory plant. Target I. pallida plants were grown alone or with one, two, or three garlic mustard neighbors. Half of the pots exposed to garlic mustard were inoculated with conidia of E. cruciferarum. Competition with garlic mustard moderately affected aboveground growth of I. pallida, particularly at high garlic mustard density, but it strongly reduced seed output across all densities. In contrast, inoculation of garlic mustard plants with E. cruciferarum completely abolished their competitive impact on seed output of I. pallida across all densities, independent of effects on aboveground growth of target plants. This effect was likely due to alteration in the ability of garlic mustard to compete for belowground resources. Even without killing garlic mustard, these results indicate that the presence of powdery mildew disease in the field will likely dampen the competitive impact of garlic mustard on individual plants and plant communities. Escape from such attackers has likely contributed to the invasiveness and impacts of garlic mustard in North America.


CATENA ◽  
2017 ◽  
Vol 150 ◽  
pp. 256-260 ◽  
Author(s):  
Qian Zhang ◽  
Junjie Yang ◽  
Roger T. Koide ◽  
Tao Li ◽  
Haishui Yang ◽  
...  

2014 ◽  
Vol 56 (1) ◽  
pp. 155-167 ◽  
Author(s):  
Barbara Sudnik-Wójcikowska

<em>Iva xanthiifolia</em> Nutt., a north-American therophyte has been recorded in Warsaw only for the last 25-40 years. Here, it occurs as a ruderal epoecophyte. It may be considered as an invasive species in the town as it spreads very quickly. The paper represents the attempt at the determination of the coenological amplitude of <em>Iva xanthiifolia</em> Nutt. It also considers syntaxonomic affiliation of the communities with this species on the grounds of the deductive method of syntaxonomic classification of anthropogenic plant communities.


2019 ◽  
Vol 84 (3) ◽  
pp. 534-541 ◽  
Author(s):  
Todd W. Arnold ◽  
Ray T. Alisauskas ◽  
James S. Sedinger
Keyword(s):  

2015 ◽  
Vol 8 (3) ◽  
pp. 292-306 ◽  
Author(s):  
John Derek Scasta ◽  
David M. Engle ◽  
Samuel D. Fuhlendorf ◽  
Daren D. Redfearn ◽  
Terrance G. Bidwell

AbstractIntroducing exotic forages in the attempt to enhance livestock and wildlife forage has been practiced widely for over a century. These forage species are selected for traits conferring persistence under stress, potentially yielding invaders that transform native plant communities. Using standardized systematic review guidelines and meta-analytical techniques we quantified effects of exotic forage invasion on change of native plant community structure, and compared the magnitude and direction of change across exotic forage species, plant functional groups, and structure of plant communities. Our study of 13 exotic forage species in North America (six C4 grasses, three C3 grasses, and four legumes) yielded 35 papers with quantitative data from 64 case studies. Nine of the 13 species met our inclusion criteria for meta-analysis. The overall effect of exotic forage invasion on native plant communities was negative (Ē̄ = −0.74; 95% confidence interval [CI]: −0.29 to −0.25). The effect size was most negative for two C4 grasses, Lehmann lovegrass and Old World bluestems. A negative effect was also expressed by C3 and C4 grass functional groups, and these effects were stronger than for legumes. Effect size differed among measures of plant community structure, with the greatest negative effect on native plant biomass and the least negative effect on species evenness. Weighted fail-safe numbers indicated publication bias was not an issue. Exotic forage species are important for agricultural production but may threaten complex multi-functioning landscapes and should be considered as a subset of potentially invasive exotic species. Characteristics making exotic forages different from other exotic plants hinge on pathways of selection and dispersion: selection is based on persistence mechanisms similar to characteristics of invasive plants; dispersion by humans is intentional across expansive geographic regions. Exotic forages present a complex socio-ecological problem exacerbated by disconnected scientific disciplines, competing interests between policy and science, and organized efforts to increase food production.


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