Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Predicting invasion in grassland ecosystems
T2 - is exotic dominance the real embarrassment of richness?
AU - Seabloom, Eric W.
AU - Borer, Elizabeth T.
AU - Buckley, Yvonne
AU - Cleland, Elsa E.
AU - Davies, Kendi
AU - Firn, Jennifer
AU - Harpole, W. Stanley
AU - Hautier, Yann
AU - Lind, Eric
AU - Macdougall, Andrew
AU - Orrock, John L.
AU - Prober, Suzanne M.
AU - Adler, Peter
AU - Alberti, Juan
AU - Michael Anderson, T.
AU - Bakker, Jonathan D.
AU - Biederman, Lori A.
AU - Blumenthal, Dana
AU - Brown, Cynthia S.
AU - Brudvig, Lars A.
AU - Caldeira, Maria
AU - Chu, Chengjin
AU - Crawley, Michael J.
AU - Daleo, Pedro
AU - Damschen, Ellen I.
AU - D'antonio, Carla M.
AU - Decrappeo, Nicole M.
AU - Dickman, Chris R.
AU - Du, Guozhen
AU - Fay, Philip A.
AU - Frater, Paul
AU - Gruner, Daniel S.
AU - Hagenah, Nicole
AU - Hector, Andrew
AU - Helm, Aveliina
AU - Hillebrand, Helmut
AU - Hofmockel, Kirsten S.
AU - Humphries, Hope C.
AU - Iribarne, Oscar
AU - Jin, Virginia L.
AU - Kay, Adam
AU - Kirkman, Kevin P.
AU - Klein, Julia A.
AU - Knops, Johannes M. H.
AU - La Pierre, Kimberly J.
AU - Ladwig, Laura M.
AU - Lambrinos, John G.
AU - Leakey, Andrew D. B.
AU - Li, Qi
AU - Li, Wei
AU - Mcculley, Rebecca
AU - Melbourne, Brett
AU - Mitchell, Charles E.
AU - Moore, Joslin L.
AU - Morgan, John
AU - Mortensen, Brent
AU - O'halloran, Lydia R.
AU - Pärtel, Meelis
AU - Pascual, Jesús
AU - Pyke, David A.
AU - Risch, Anita C.
AU - Salguero-gómez, Roberto
AU - Sankaran, Mahesh
AU - Schuetz, Martin
AU - Simonsen, Anna
AU - Smith, Melinda
AU - Stevens, Carly
AU - Sullivan, Lauren
AU - Wardle, Glenda M.
AU - Wolkovich, Elizabeth M.
AU - Wragg, Peter D.
AU - Wright, Justin
AU - Yang, Louie
PY - 2013/12/1
Y1 - 2013/12/1
N2 - Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring species' relative abundance will more rapidly advance our understanding of invasions.
AB - Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring species' relative abundance will more rapidly advance our understanding of invasions.
U2 - 10.1111/gcb.12370
DO - 10.1111/gcb.12370
M3 - Journal article
VL - 19
SP - 3677
EP - 3687
JO - Global Change Biology
JF - Global Change Biology
SN - 1354-1013
IS - 12
ER -