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Species interactions determine the spatial mortality patterns emerging in plant communities after extreme events.

Liao J, Bogaert J, Nijs I - Sci Rep (2015)

Bottom Line: Under interspecific competition, both gap metrics interestingly increased with species richness, while they were reduced under intraspecific competition.Increasing conspecific clumping induced larger gaps with more variable sizes under intraspecific competition, in contrast to interspecific competition.Overall, our "static" model on gap formation offers perspectives to better predict recolonization opportunity and thus community secondary succession under extreme event regimes.

View Article: PubMed Central - PubMed

Affiliation: 1] Research Group Plant and Vegetation Ecology, Department of Biology, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, B-2610 Wilrijk, Belgium [2] Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, Jiangxi Normal University, Ziyang Road 99, 330022 Nanchang, China.

ABSTRACT
Gap disturbance is assumed to maintain species diversity by creating environmental heterogeneity. However, little is known about how interactions with neighbours, such as competition and facilitation, alter the emerging gap patterns after extreme events. Using a spatially explicit community model we demonstrate that negative interactions, especially intraspecific competition, greatly promote both average gap size and gap-size diversity relative to positive interspecific interaction. This suggests that competition would promote diversity maintenance but also increase community invasibility, as large gaps with a wide size variety provide more diverse niches for both local and exotic species. Under interspecific competition, both gap metrics interestingly increased with species richness, while they were reduced under intraspecific competition. Having a wider range of species interaction strengths led to a smaller average gap size only under intraspecific competition. Increasing conspecific clumping induced larger gaps with more variable sizes under intraspecific competition, in contrast to interspecific competition. Given the range of intraspecific clumping in real communities, models or experiments based on randomly synthesized communities may yield biased estimates of the opportunities for potential colonizers to fill gaps. Overall, our "static" model on gap formation offers perspectives to better predict recolonization opportunity and thus community secondary succession under extreme event regimes.

No MeSH data available.


Effect of intraspecific clumping (p) on gap metrics (mean ± SD of 100 replicates) under different species interactions (case 3 in Table 1, see Fig. 1 for interactions).
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f3: Effect of intraspecific clumping (p) on gap metrics (mean ± SD of 100 replicates) under different species interactions (case 3 in Table 1, see Fig. 1 for interactions).

Mentions: Thirdly, we explored how intraspecific aggregation p modulates the effects of species interactions on gap metrics (Fig. 3). Similar to Figs. 1 and 2, inter(+,+) yielded a lower average gap size but similar gap-size diversity compared to neutral conditions (0,0), regardless of intraspecific clumping (all values were low). On the other hand, intraspecific aggregation largely altered the effects of inter- and intraspecific competition on the gap pattern. Under interspecific competition, the average gap size and gap-size diversity reached a maximum in randomly structured communities (i.e., p = 0), and declined exponentially with aggregation. This can be understood from the fact that randomly distributed communities have maximum interspecific contacts, so large numbers of individuals suffer from competition (note that over-dispersed communities, which were not simulated in this study, would probably yield larger gaps with higher gap-size diversity when facing extreme disturbance, as their intraspecific clumping is lower than randomly synthesized communities, inducing dominance of interspecific competition). In contrast, at p = 0, intraspecific contacts are minimized, hence the influence of intraspecific competition on gap formation is also minimal, resulting in the smallest average gap size and lowest gap-size diversity. With increasing clumping degree, both gap metrics increased rapidly as more and more individuals then experience intraspecific competition.


Species interactions determine the spatial mortality patterns emerging in plant communities after extreme events.

Liao J, Bogaert J, Nijs I - Sci Rep (2015)

Effect of intraspecific clumping (p) on gap metrics (mean ± SD of 100 replicates) under different species interactions (case 3 in Table 1, see Fig. 1 for interactions).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4459219&req=5

f3: Effect of intraspecific clumping (p) on gap metrics (mean ± SD of 100 replicates) under different species interactions (case 3 in Table 1, see Fig. 1 for interactions).
Mentions: Thirdly, we explored how intraspecific aggregation p modulates the effects of species interactions on gap metrics (Fig. 3). Similar to Figs. 1 and 2, inter(+,+) yielded a lower average gap size but similar gap-size diversity compared to neutral conditions (0,0), regardless of intraspecific clumping (all values were low). On the other hand, intraspecific aggregation largely altered the effects of inter- and intraspecific competition on the gap pattern. Under interspecific competition, the average gap size and gap-size diversity reached a maximum in randomly structured communities (i.e., p = 0), and declined exponentially with aggregation. This can be understood from the fact that randomly distributed communities have maximum interspecific contacts, so large numbers of individuals suffer from competition (note that over-dispersed communities, which were not simulated in this study, would probably yield larger gaps with higher gap-size diversity when facing extreme disturbance, as their intraspecific clumping is lower than randomly synthesized communities, inducing dominance of interspecific competition). In contrast, at p = 0, intraspecific contacts are minimized, hence the influence of intraspecific competition on gap formation is also minimal, resulting in the smallest average gap size and lowest gap-size diversity. With increasing clumping degree, both gap metrics increased rapidly as more and more individuals then experience intraspecific competition.

Bottom Line: Under interspecific competition, both gap metrics interestingly increased with species richness, while they were reduced under intraspecific competition.Increasing conspecific clumping induced larger gaps with more variable sizes under intraspecific competition, in contrast to interspecific competition.Overall, our "static" model on gap formation offers perspectives to better predict recolonization opportunity and thus community secondary succession under extreme event regimes.

View Article: PubMed Central - PubMed

Affiliation: 1] Research Group Plant and Vegetation Ecology, Department of Biology, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, B-2610 Wilrijk, Belgium [2] Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, Jiangxi Normal University, Ziyang Road 99, 330022 Nanchang, China.

ABSTRACT
Gap disturbance is assumed to maintain species diversity by creating environmental heterogeneity. However, little is known about how interactions with neighbours, such as competition and facilitation, alter the emerging gap patterns after extreme events. Using a spatially explicit community model we demonstrate that negative interactions, especially intraspecific competition, greatly promote both average gap size and gap-size diversity relative to positive interspecific interaction. This suggests that competition would promote diversity maintenance but also increase community invasibility, as large gaps with a wide size variety provide more diverse niches for both local and exotic species. Under interspecific competition, both gap metrics interestingly increased with species richness, while they were reduced under intraspecific competition. Having a wider range of species interaction strengths led to a smaller average gap size only under intraspecific competition. Increasing conspecific clumping induced larger gaps with more variable sizes under intraspecific competition, in contrast to interspecific competition. Given the range of intraspecific clumping in real communities, models or experiments based on randomly synthesized communities may yield biased estimates of the opportunities for potential colonizers to fill gaps. Overall, our "static" model on gap formation offers perspectives to better predict recolonization opportunity and thus community secondary succession under extreme event regimes.

No MeSH data available.