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Ecological application of biotic resistance to control the invasion of an invasive plant, Ageratina altissima

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ABSTRACT

Biotic resistance is the ability of species in a community to limit the invasion of other species. However, biotic resistance is not widely used to control invasive plants. Experimental, functional, and modeling approaches were combined to investigate the processes of invasion by Ageratina altissima (white snakeroot), a model invasive species in South Korea. We hypothesized that (1) functional group identity would be a good predictor of biotic resistance to A. altissima, whereas a species identity effect would be redundant within a functional group, and (2) mixtures of species would be more resistant to invasion than monocultures. We classified 37 species of native plants into three functional groups based on seven functional traits. The classification of functional groups was based primarily on differences in life longevity and woodiness. A competition experiment was conducted based on an additive competition design with A. altissima and monocultures or mixtures of resident plants. As an indicator of biotic resistance, we calculated a relative competition index (RCIavg) based on the average performance of A. altissima in a competition treatment compared with that of the control where only seeds of A. altissima were sown. To further explain the effect of diversity, we tested several diversity–interaction models. In monoculture treatments, RCIavg of resident plants was significantly different among functional groups but not within each functional group. Fast‐growing annuals (FG1) had the highest RCIavg, suggesting priority effects (niche pre‐emption). RCIavg of resident plants was significantly greater in a mixture than in a monoculture. According to the diversity–interaction models, species interaction patterns in mixtures were best described by interactions between functional groups, which implied niche partitioning. Functional group identity and diversity of resident plant communities were good indicators of biotic resistance to invasion by introduced A. altissima, with the underlying mechanisms likely niche pre‐emption and niche partitioning. This method has most potential in assisted restoration contexts, where there is a desire to reintroduce natives or boost their population size due to some previous level of degradation.

No MeSH data available.


Comparisons between monoculture and mixture treatments. RCIavg: relative competition index of resident plant(s) as an indicator of biotic resistance (see Equation (1)). The same letter indicates that means are not significantly different from one another. Error bar represents the standard error
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ece32799-fig-0004: Comparisons between monoculture and mixture treatments. RCIavg: relative competition index of resident plant(s) as an indicator of biotic resistance (see Equation (1)). The same letter indicates that means are not significantly different from one another. Error bar represents the standard error

Mentions: Mixtures of resident plants were more resistant to invasion than monocultures, and this diversity effect on biotic resistance was the result of positive interactions between FG1 and FG3 (Figuress 4 and 5). RCIavg was significantly greater in mixtures than in monocultures (F1,53 = 4.08; p = .048; Figure 4). Aboveground biomass of resident species was also significantly greater in mixture treatments than in monoculture treatments (F1,53 = 7.33; p < .009).


Ecological application of biotic resistance to control the invasion of an invasive plant, Ageratina altissima
Comparisons between monoculture and mixture treatments. RCIavg: relative competition index of resident plant(s) as an indicator of biotic resistance (see Equation (1)). The same letter indicates that means are not significantly different from one another. Error bar represents the standard error
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC5383480&req=5

ece32799-fig-0004: Comparisons between monoculture and mixture treatments. RCIavg: relative competition index of resident plant(s) as an indicator of biotic resistance (see Equation (1)). The same letter indicates that means are not significantly different from one another. Error bar represents the standard error
Mentions: Mixtures of resident plants were more resistant to invasion than monocultures, and this diversity effect on biotic resistance was the result of positive interactions between FG1 and FG3 (Figuress 4 and 5). RCIavg was significantly greater in mixtures than in monocultures (F1,53 = 4.08; p = .048; Figure 4). Aboveground biomass of resident species was also significantly greater in mixture treatments than in monoculture treatments (F1,53 = 7.33; p < .009).

View Article: PubMed Central - PubMed

ABSTRACT

Biotic resistance is the ability of species in a community to limit the invasion of other species. However, biotic resistance is not widely used to control invasive plants. Experimental, functional, and modeling approaches were combined to investigate the processes of invasion by Ageratina altissima (white snakeroot), a model invasive species in South Korea. We hypothesized that (1) functional group identity would be a good predictor of biotic resistance to A.&nbsp;altissima, whereas a species identity effect would be redundant within a functional group, and (2) mixtures of species would be more resistant to invasion than monocultures. We classified 37 species of native plants into three functional groups based on seven functional traits. The classification of functional groups was based primarily on differences in life longevity and woodiness. A competition experiment was conducted based on an additive competition design with A.&nbsp;altissima and monocultures or mixtures of resident plants. As an indicator of biotic resistance, we calculated a relative competition index (RCIavg) based on the average performance of A.&nbsp;altissima in a competition treatment compared with that of the control where only seeds of A.&nbsp;altissima were sown. To further explain the effect of diversity, we tested several diversity&ndash;interaction models. In monoculture treatments, RCIavg of resident plants was significantly different among functional groups but not within each functional group. Fast&#8208;growing annuals (FG1) had the highest RCIavg, suggesting priority effects (niche pre&#8208;emption). RCIavg of resident plants was significantly greater in a mixture than in a monoculture. According to the diversity&ndash;interaction models, species interaction patterns in mixtures were best described by interactions between functional groups, which implied niche partitioning. Functional group identity and diversity of resident plant communities were good indicators of biotic resistance to invasion by introduced A.&nbsp;altissima, with the underlying mechanisms likely niche pre&#8208;emption and niche partitioning. This method has most potential in assisted restoration contexts, where there is a desire to reintroduce natives or boost their population size due to some previous level of degradation.

No MeSH data available.