TY - JOUR
T1 - Native insect herbivory limits population growth rate of a non-native thistle
AU - Eckberg, James O.
AU - Tenhumberg, Brigitte
AU - Louda, Svata M.
PY - 2014/5
Y1 - 2014/5
N2 - The influence of native fauna on non-native plant population growth, size, and distribution is not well documented. Previous studies have shown that native insects associated with tall thistle (Cirsium altissimum) also feed on the leaves, stems, and flower heads of the Eurasian congener C. vulgare, thus limiting individual plant performance. In this study, we tested the effects of insect herbivores on the population growth rate of C. vulgare. We experimentally initiated invasions by adding seeds at four unoccupied grassland sites in eastern Nebraska, USA, and recorded plant establishment, survival, and reproduction. Cumulative foliage and floral herbivory reduced C. vulgare seedling density, and prevented almost any reproduction by C. vulgare in half the sites. The matrix model we constructed showed that this herbivory resulted in a reduction of the asymptotic population growth rate (λ), from an 88 % annual increase to a 54 % annual decline. These results provide strong support for the hypothesis that indigenous herbivores limit population invasion of this non-native plant species into otherwise suitable grassland habitat.
AB - The influence of native fauna on non-native plant population growth, size, and distribution is not well documented. Previous studies have shown that native insects associated with tall thistle (Cirsium altissimum) also feed on the leaves, stems, and flower heads of the Eurasian congener C. vulgare, thus limiting individual plant performance. In this study, we tested the effects of insect herbivores on the population growth rate of C. vulgare. We experimentally initiated invasions by adding seeds at four unoccupied grassland sites in eastern Nebraska, USA, and recorded plant establishment, survival, and reproduction. Cumulative foliage and floral herbivory reduced C. vulgare seedling density, and prevented almost any reproduction by C. vulgare in half the sites. The matrix model we constructed showed that this herbivory resulted in a reduction of the asymptotic population growth rate (λ), from an 88 % annual increase to a 54 % annual decline. These results provide strong support for the hypothesis that indigenous herbivores limit population invasion of this non-native plant species into otherwise suitable grassland habitat.
KW - Biotic resistance
KW - Bull thistle
KW - Cirsium vulgare
KW - Ecosystem service
KW - Invasion
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U2 - 10.1007/s00442-013-2876-4
DO - 10.1007/s00442-013-2876-4
M3 - Article
C2 - 24402131
AN - SCOPUS:84901458404
SN - 0029-8549
VL - 175
SP - 129
EP - 138
JO - Oecologia
JF - Oecologia
IS - 1
ER -