caa a22 4500 445869801 CHVBK 20180317145508.0 cr unu---uuuuu 170323e20110301xx s 000 0 eng 10.1007/s11101-010-9195-8 doi (NATIONALLICENCE)springer-10.1007/s11101-010-9195-8 A review of the phytochemical support for the shifting defence hypothesis [Elektronische Daten] [Leonie Doorduin, Klaas Vrieling] Several theories have been developed to explain why invasive species are very successful and develop into pest species in their new area. The shifting defence hypothesis (SDH) argues that invasive plant species quickly evolve towards new defence levels in the invaded area because they lack their specialist herbivores but are still under attack by local (new) generalist herbivores. The SDH predicts that plants should increase their cheap, toxic defence compounds and lower their expensive digestibility reducing compounds. As a net result resources are saved that can be allocated to growth and reproduction giving these plants a competitive edge over the local plant species. We conducted a literature study to test whether toxic defence compounds in general are increased in the invaded area and if digestibility reducing compounds are lowered. We specifically studied the levels of pyrrolizidine alkaloids, a toxin which is known for its beneficial and detrimental impact against specialists and generalists, respectively. Digestibility reducers did not show a clear trend which might be due to the small number of studies and traits measured. The meta analysis showed that toxic compounds in general and pyrrolizidine alkaloid levels specifically, increased significantly in the invaded area, supporting the predictions of the SDH that a fast evolution takes place in the allocation towards defence. The Author(s), 2010 Defence nationallicence EICA nationallicence Invasion nationallicence PAs nationallicence SDH nationallicence Doorduin Leonie Ecology and Phytochemistry, Institute of Biology, Leiden University, PO Box 9505, 2300 RA, Leiden, The Netherlands aut Vrieling Klaas Ecology and Phytochemistry, Institute of Biology, Leiden University, PO Box 9505, 2300 RA, Leiden, The Netherlands aut Phytochemistry Reviews Springer Netherlands 10/1(2011-03-01), 99-106 1568-7767 10:1<99 2011 10 11101 https://doi.org/10.1007/s11101-010-9195-8 text/html Onlinezugriff via DOI 1 review-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11101-010-9195-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Doorduin Leonie Ecology and Phytochemistry, Institute of Biology, Leiden University, PO Box 9505, 2300 RA, Leiden, The Netherlands aut NATIONALLICENCE 700 1- Vrieling Klaas Ecology and Phytochemistry, Institute of Biology, Leiden University, PO Box 9505, 2300 RA, Leiden, The Netherlands aut NATIONALLICENCE 773 0- Phytochemistry Reviews Springer Netherlands 10/1(2011-03-01), 99-106 1568-7767 10:1<99 2011 10 11101 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer