scholarly journals Meta-Analysis of Exotic Forages as Invasive Plants in Complex Multi-Functioning Landscapes

2015 ◽  
Vol 8 (3) ◽  
pp. 292-306 ◽  
Author(s):  
John Derek Scasta ◽  
David M. Engle ◽  
Samuel D. Fuhlendorf ◽  
Daren D. Redfearn ◽  
Terrance G. Bidwell
Keyword(s):  
Community Structure ◽  
Plant Community ◽  
Plant Communities ◽  
Invasive Plants ◽  
Effect Size ◽  
Meta Analysis ◽  
Plant Community Structure ◽  
Native Plant ◽  
Forage Species ◽  
Negative Effect

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.

scholarly journals Within-species phylogenetic relatedness of a common mycorrhizal fungus affects evenness in plant communities through effects on dominant species

2018 ◽  
Author(s):  
Romain Savary ◽  
Lucas Villard ◽  
Ian R. Sanders
Keyword(s):  
Community Structure ◽  
Plant Community ◽  
Plant Communities ◽  
Mycorrhizal Fungi ◽  
Mycorrhizal Fungus ◽  
Species Variation ◽  
Plant Community Structure ◽  
Growth Responses ◽  
Differential Effects ◽  
The Impact

AbstractArbuscular mycorrhizal fungi (AMF) have been shown to influence plant community structure and diversity. Studies based on single plant - single AMF isolate experiments show that within AMF species variation leads to large differential growth responses of different plant species. Because of these differential effects, genetic differences among isolates of an AMF species could potentially have strong effects on the structure of plant communities.We tested the hypothesis that within species variation in the AMF R. irregularis significantly affects plant community structure and plant co-existence. We took advantage of a recent genetic characterization of several isolates using double-digest restriction-site associated DNA sequencing (ddRADseq). This allowed us to test not only for the impact of within AMF species variation on plant community structure but also for the role of the R. irregularis phylogeny on plant community metrics. Nine isolates of R. irregularis, belonging to three different genetic groups (Gp1, Gp3 and Gp4), were used as either single inoculum or as mixed diversity inoculum. Plants in a mesocosm representing common species that naturally co-exist in European grasslands were inoculated with the different AMF treatments.We found that within-species differences in R. irregularis did not strongly influence the performance of individual plants or the structure of the overall plant community. However, the evenness of the plant community was affected by the phylogeny of the fungal isolates, where more closely-related AMF isolates were more likely to affect plant community evenness in a similar way compared to more genetically distant isolates.This study underlines the effect of within AMF species variability on plant community structure. While differential effects of the AMF isolates were not strong, a single AMF species had enough functional variability to change the equilibrium of a plant community in a way that is associated with the evolutionary history of the fungus.

scholarly journals Antigonon leptopus invasion is associated with plant community disassembly in a Caribbean island ecosystem

2021 ◽  
Author(s):  
Maarten B. Eppinga ◽  
Elizabeth A. Haber ◽  
Luke Sweeney ◽  
Maria J. Santos ◽  
Max Rietkerk ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Plant Community ◽  
Plant Communities ◽  
Biodiversity Loss ◽  
Native Plant ◽  
Tropical Islands ◽  
Caribbean Island ◽  
Occurrence Patterns ◽  
The Impact

AbstractInvasions by non-native plant species are widely recognized as a major driver of biodiversity loss. Globally, (sub-)tropical islands form important components of biodiversity hotspots, while being particularly susceptible to invasions by plants in general and vines in particular. We studied the impact of the invasive vine A. leptopus on the diversity and structure of recipient plant communities on the northern Caribbean island St. Eustatius. We used a paired-plot design to study differences in species richness, evenness and community structure under A. leptopus-invaded and uninvaded conditions. Community structure was studied through species co-occurrence patterns. We found that in plots invaded by A. leptopus, species richness was 40–50% lower, and these plots also exhibited lower evenness. The magnitude of these negative impacts increased with increasing cover of A. leptopus. Invaded plots also showed higher degrees of homogeneity in species composition. Species co-occurrence patterns indicated that plant communities in uninvaded plots were characterized by segregation, whereas recipient plant communities in invaded plots exhibited random co-occurrence patterns. These observations suggest that invasion of A. leptopus is not only associated with reduced species richness and evenness of recipient communities in invaded sites, but also with a community disassembly process that may reduce diversity between sites. Given that A. leptopus is a successful invader of (sub-)tropical islands around the globe, these impacts on plant community structure highlight that this invasive species could be a particular conservation concern for these systems.

scholarly journals Determinants of native and non-native plant community structure on an oceanic island

Ecosphere ◽  
2017 ◽  
Vol 8 (9) ◽  
pp. e01927 ◽  
Author(s):  
Shishir Paudel ◽  
Juan C. Benavides ◽  
Beau MacDonald ◽  
Travis Longcore ◽  
Gail W. T. Wilson ◽  
...  
Keyword(s):  
Community Structure ◽  
Plant Community ◽  
Oceanic Island ◽  
Plant Community Structure ◽  
Native Plant ◽  
Native Plant Community

scholarly journals The Cooling and Humidifying Effects and the Thresholds of Plant Community Structure Parameters in Urban Aggregated Green Infrastructure

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 111
Author(s):  
Jiaxing Wei ◽  
Hongbo Li ◽  
Yuncai Wang ◽  
Xizi Xu
Keyword(s):  
Community Structure ◽  
Plant Community ◽  
Plant Communities ◽  
Green Infrastructure ◽  
Vegetation Type ◽  
Structure Parameters ◽  
Plant Community Structure ◽  
Canopy Density ◽  
Positive Correlation ◽  
Optimal Thresholds

The cooling and humidifying effects of urban aggregated green infrastructure can provide essential services for city ecosystems, regulating microclimates or mitigating the urban heat island effect. However, the optimal thresholds of plant community structure parameters for maximizing the associated cooling and humidifying effects remain unclear. In this paper, we use the method of dummy variable regression to measure plant communities in an urban aggregated green infrastructure. By examining the relationships between the cooling and humidifying effects and plant community structure parameters (i.e., canopy density, porosity, and vegetation type), we introduce optimal thresholds for the parameters. We find that canopy density has a significantly positive correlation with both cooling and humidifying effects, while porosity has a positive correlation with cooling and a negative one with humidifying. Different vegetation types have distinct influences on cooling and humidifying effects. When the canopy density is between 0.81 and 0.85 and the porosity is between 0.31 and 0.35, the cooling and humidifying effects of the plant communities reach their peak. Additionally, the greening coverage rate and spatial types of urban aggregated green infrastructure have influences on cooling and humidifying effects. The findings can help us to better understand the relationships between plant community structure parameters and their temperature regulation functioning for urban aggregated green infrastructure. This study provides guidelines and theoretical references for the plant configuration of future urban green spaces.

Relating pine-litter intrusion to plant-community structure in native eucalypt woodland adjacent to Pinus radiata (Pinaceae) plantations

2007 ◽  
Vol 55 (5) ◽  
pp. 521 ◽  
Author(s):  
Andrew C. Baker ◽  
Brad R. Murray ◽  
Grant C. Hose
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Plant Species ◽  
Plant Community ◽  
Plant Species Richness ◽  
Radiata Pine ◽  
Plant Community Structure ◽  
Native Plant ◽  
Native Plant Species ◽  
Eucalypt Woodland

Radiata pine (Pinus radiata D.Don) plantations are often found in close proximity to vegetation set aside for biodiversity conservation. We examined the intrusive effects of radiata pine beyond the confines of plantations by quantifying the penetration of pine litter (needles, cones, twigs and seeds) and wildings from plantations into adjacent eucalypt woodland in the Jenolan Caves Karst Conservation Reserve (south-eastern Australia). We then investigated the relationship between pine-litter intrusion and plant-community structure in adjacent woodland vegetation. We found significantly higher quantities of pine litter and wildings at all sites adjacent to plantations than at reference woodland sites that were not adjacent to plantations. At adjacent sites, pine litter decreased significantly with increasing distance from plantations. Alarmingly, native plant species richness declined and exotic plant species richness increased with increasing quantities of pine litter. Thus, there were fewer native plant species and more exotics in areas bordering pine plantations. Our findings suggest a potentially important link between the intrusion of pine litter and a loss of native biodiversity and facilitation of exotic-species invasion. We suggest the provision of a buffer zone around plantations in order to minimise intrusive impacts of plantations on native biodiversity.

Plant Community Structure of Tropical Semi-Evergreen Forest of Reiek in Mamit District of Mizoram

2017 ◽  
Vol 5 (1) ◽  
pp. 58-62 ◽  
Author(s):  
S.T. Lalzarzovi ◽  
◽  
Lalnun Tluanga
Keyword(s):  
Community Structure ◽  
Structural Analysis ◽  
Plant Communities ◽  
Ecological Study ◽  
Life Form ◽  
Evergreen Forest ◽  
Biodiversity Hotspots ◽  
Plant Community Structure ◽  
Floristic Survey ◽  
Normal Spectrum

Ecological study of tropical semi-evergreen forest of Reiek in Mizoram was carried out to determine the stratification of the forest as well as to prepare life form spectrum of the plant communities. Mizoram is a part of Indo- Myanmar region which falls under one of the 35 biodiversity hotspots identified worldwide and therefore has a rich biodiversity. A detailed floristic survey was carried out. Plant species were collected, mounted in herbarium sheets and identified. Structural analysis was carried out and profile diagram was drawn. The forest was found to be composed of three layers in both the disturbed and undisturbed areas of the forest. The life form spectrum has been compared with Raunkiers normal spectrum to find out the phytoclimate of the region. The study area was found to have an abundance of phanerophytes indicating a phanerophytic climate

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