Identifying the drivers of changes in the relative abundances of species in agroecosystems
Authors
Brophy, C., Finn, J. A., Lüscher, A., Suter, M., Kirwan, L., Sebastià, M. T., Helgadóttir, Á., Baadshaug, O. H., Bélanger, G., Black, Alistair, Collins, R. P., Čop, J., Dalmannsdóttir, S., Delgado, I., Elgersma, A., Fothergill, M., Frankow-Lindberg, B. E., Ghesquiere, A., Golińska, B., Goliński, P., Grieu, P., Gustavsson, A. M., Höglind, M., Huguenin-Elie, O., Jørgensen, M., Kadziuliene, Z., Kurki, P., Llurba, R., Lunnan, T., Porqueddu, C., Thumm, U., Connolly, J.
Date
2018
Type
Conference Contribution - published
Collections
Fields of Research
Abstract
Increasing species diversity often promotes ecosystem functions in grasslands, but sward diversity may be reduced over time through competitive interactions among species. We investigated the development of species’ relative abundances in intensively managed agricultural grassland mixtures over three years to identify the drivers of diversity change. A continental-scale field experiment was conducted at 31 sites using 11 different four-species mixtures each sown at two seed abundances. The four species consisted of two grasses and two legumes, of which one was fast establishing and the other temporally persistent. We modelled the dynamics of the four-species mixtures over the three-year period. The relative abundances shifted substantially over time; in particular, the relative abundance of legumes declined over time but stayed above 15% in year three at many sites. We found that species’ dynamics were primarily driven by differences in the relative growth rates of competing species and secondarily by density dependence and climate. Alongside this, positive diversity effects in yield were found in all years at many sites.
Permalink
Source DOI
Rights
© 2018 All rights reserved. Nothing from this publication may be reproduced, stored in computerised systems or published in any form or any manner, including electronic, mechanical, reprographic or photographic, without prior written permission from the publisher. The individual contributions in this publication and any liabilities arising from them remain the responsibility of the authors.