Multi-scale analyses of exotic and native plant species diversity within Canada’s endangered antelope-brush ecosystem

Symonds, Josephine Elizabeth; Pither, Jason

doi:10.1007/s11258-012-0084-7

Cited by 8 publications

(7 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This supports our hypothesis that natives and exotics would positively covary due to shared external drivers (Shea and Chesson 2002;Davies et al 2005). Mechanisms underlying this shared response are likely to involve independent direct responses of both natives and exotics to rainfall, although a common response could also be mediated by facilitation of native by exotic, or exotic by native species (Brooker 2006;Mitchell et al 2006;Symonds and Pither 2012).…”

Section: Native-exotic Relationshipssupporting

confidence: 85%

“…However, positive relationships are also widely reported at local scales (Fridley et al 2007;Bennett et al 2012), potentially resulting from common response to management or resources, and potentially mediated by biotic interactions such as facilitation of exotics by natives or vice versa (e.g. Brooker 2006;Mitchell et al 2006;Symonds and Pither 2012). Positive relationships imply that management of external drivers to promote natives may also promote exotics, and management to suppress exotics may also suppress natives.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Competing drivers lead to non-linear native–exotic relationships in endangered temperate grassy woodlands

2016

View full text Add to dashboard Cite

Relationships between the diversity and abundance of native versus exotic species underpin management of disturbance regimes for conservation. Theory predicts negative, positive or neutral relationships depending on respective drivers, with greatest potential benefit when natives and exotics show opposing responses to management. We examined drivers of exotic plant cover and relationships with native plant richness using 12-year burning, mowing and grazing experiments in two representative temperate grassy eucalypt woodlands with contrasting histories of frequent versus infrequent disturbance. We hypothesized that disturbance and high resources favour exotics, and assessed whether natives and exotics covary positively due to common external drivers or negatively due to contrasting external drivers and/or competition. Positive relationships with rainfall and disturbance explained [80 % of the variation in exotic cover at both sites, supporting our first hypothesis. Native-exotic relationships were nonlinear, with native richness first increasing rapidly with increasing exotic cover, then levelling and beginning to decrease. Common external drivers, particularly inter-annual rainfall, explained initial positive relationships, highlighting a prevalence of positive relationships at long temporal (as well as large spatial) scales. At the historically frequently-burnt site, a concomitant increase in native richness and exotic cover after fire contributed to the positive relationship, indicating a management trade-off. At the long-unburnt site, exotics increased but natives decreased with fire, suggesting dual benefits of low fire frequency. We conclude that relationships between exotic cover and native richness emerge from interactions among external drivers and competitive responses, with responses to external drivers dominating at low resources and negative interactions gaining importance as resources increase.Electronic supplementary material The online version of this article (

show abstract

Section: Native-exotic Relationshipssupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Competing drivers lead to non-linear native–exotic relationships in endangered temperate grassy woodlands

2016

View full text Add to dashboard Cite

show abstract

“…In theory, regional processes can interact with local processes to affect NERR patterns. Spatial extent has not received much explicit attention in the discussion of scale and NERR, but several studies suggest that extent may be important in determining NERR patterns (Sandel and Corbin , Symonds and Pither ). Our results, however, indicated that spatial extent plays a less important and less clear role than does grain.…”

Section: Discussionmentioning

confidence: 99%

Correlation of native and exotic species richness: a global meta‐analysis finds no invasion paradox across scales

Peng

Kinlock

Gurevitch

et al. 2019

Ecology

110

View full text Add to dashboard Cite

Support for the “biotic resistance hypothesis,” that species‐rich communities are more successful at resisting invasion by exotic species than are species‐poor communities, has long been debated. It has been argued that native–exotic richness relationships (NERR) are negative at small spatial scales and positive at large scales, but evidence for the role of spatial scale on NERR has been contradictory. However, no formal quantitative synthesis has previously examined whether NERR is scale‐dependent across multiple studies, and previous studies on NERR have not distinguished spatial grain and extent, which may drive very different ecological processes. We used a global systematic review and hierarchical mixed‐effects meta‐analysis to provide a comprehensive quantitative assessment of the patterns of NERR over a range of spatial grain sizes and spatial extents, based on 204 individual cases of observational (non‐experimental) NERRs from 101 publications. We show that NERR was indeed highly scale dependent across studies and increased with the log of grain size. However, mean NERR was not negative at any grain size, although there was high heterogeneity at small grain sizes. We found no clear patterns of NERR across different spatial extents, suggesting that extent plays a less important role in determining NERR than does grain, although there was a complex interaction between extent and grain size. Almost all studies on NERR were conducted in North America, western Europe, and a few other regions, with little information on tropical or Arctic regions. We did find that NERR increased northward in temperate regions and also varied with longitude. We discuss possible explanations for the patterns we found, and caution that our results do not show that invasive species are benign or have no negative consequences for biodiversity preservation. This study represents the first global quantitative analysis of scale‐based NERR, and casts doubt on the existence of an “invasion paradox” of negative NERR at small scales and positive correlations at large scales in non‐experimental studies.

show abstract

“…To examine the patterns on smallest scales possible, rather than across sites and/or spatial scales (e.g., Herben et al 2004;Symonds and Pither 2012), I focus on the smallest scales only (0.01-10 m 2 ) used in each individual study from the 75 cases around the world that use native (or resident) richness as the independent variable. Data from these case studies were compiled by searching Google scholar with key words such as exotic, non-native, alien, native, correlation, relationship, and scale (up to June 29, 2014; see Supplementary Table S1, Appendix S1).…”

Section: Data and Literaturementioning

confidence: 99%

No consistent small-scale native–exotic relationships

Guo

2015

Plant Ecol

View full text Add to dashboard Cite

The perception that native and exotic species are negatively related to each other at small scales has proliferated in the ecological literature. Although mounting evidence shows that such a perception is not always reality, the degree to which the mismatch occurs and the causes are not clear. Here, I compile and synthesize data based on the smallest scales used in 75 case studies in plant communities around the world, and analyze detailed data from a study in early successional California chaparral. I show that (1) different metrics (community variables) yielded different results, (2) native biomass and cover had much stronger negative effects on exotic richness than native richness and density, (3) there is no consistent correlation between native and exotic richness, especially in natural and immature communities, and (4) proportionally more experimental studies revealed negative relations than field observations. Collectively, these results reveal and confirm a high degree of mismatch between perceptions and reality in small-scale patterns of biotic invasions which have management implications.

show abstract

Multi-scale analyses of exotic and native plant species diversity within Canada’s endangered antelope-brush ecosystem

Cited by 8 publications

References 39 publications

Competing drivers lead to non-linear native–exotic relationships in endangered temperate grassy woodlands

Competing drivers lead to non-linear native–exotic relationships in endangered temperate grassy woodlands

Correlation of native and exotic species richness: a global meta‐analysis finds no invasion paradox across scales

No consistent small-scale native–exotic relationships

Contact Info

Product

Resources

About