Reduced benefits of ant occupation for ant-trees in oil palm compared with heavily logged forest M. Y. I. Houadria 1 & H. Feldhaar 2 & B. Fiala 6 & D. Lestina 1,3 & A. Chung 4 & A. Salleh 5 & H. Justin 5 & P. Kokorova 1,3 & T. M. Fayle 1,3 Received: 10 December 2019 /Accepted: 5 May 2020 # Springer Nature B.V. 2020 Abstract Understanding interactions between species in altered ecosystems is important, as they influence resilience and opportunities for restoration. Here we explore a multipartite interaction between an important early succession myrmecophytic tree in Borneo (Macaranga pearsonii), and its ant mutualists that provide protection from herbivores. We compare the mutualistic system between two highly degraded habitats that are candidates for future restoration: oil palm plantation and recently heavily-logged forest. For each tree we measured tree structure (height, diameter, number of branches), leaf biomass and herbivore damage. We also measured soil characteristics (phosphate and nitrate content, pH, density) and canopy openness as these may influence tree health. For each branch, we quantified number of ant workers, brood, alates and queens as well as number of coccids. The ants tend these symbiotic coccids for their sugar-rich exudate produced by sucking the tree’s sap. We demonstrate that herbivore damage was up to twice as high in oil palm plantation compared to heavily-logged forest. This herbivory increase was not related directly to changes in abiotic conditions or to higher herbivore pressure, but rather to the distribution of the ant workers within the trees. However, trees in oil palm were able to compensate for the increased herbivory by increasing leaf production. For similar ant abundance, fewer branches were occupied in oil palm plantation, and there were relatively more ants in the presence of coccids. Taken together, our findings indicate that although this mutualism has variation in its functioning, with reduced benefits for the tree of ant occupation in oil palm plantation, the mutualism persists in oil palm. Therefore Macaranga pearsonii is a viable candidate for forest restoration (just as in secondary forest) if these trees are allowed to grow in oil palm plantations. Keywords Myrmecophytism . Forest restoration . Coccids . Multipartite interactions . Macaranga . Crematogaster 1 Introduction All organisms on Earth are embedded in a complex network of interactions. These interactions between species can be quantified by assessing the costs and benefits for each partner. Each interaction can then be defined as competitive, predato- ry, parasitic, commensal, or mutualistic. However, the out- comes of these interactions may vary in relation to the biotic and abiotic environment (Canestrari et al. 2014). Because hu- man activities are dramatically changing the biotic and abiotic environment, understanding variation in outcomes is increas- ingly important. This is particularly true for mutualistic inter- actions, where partners may have traits that increase partner fitness that have high levels of interaction specificity, making these interactions potentially sensitive to anthropogenic dis- turbance (Palmer et al. 2008; Câmara et al. 2018). Ranges of most organisms now occur across landscapes with varying degrees of anthropogenic habitat modification (Hooke et al. 2012). Furthermore, plant mutualistic interactions underlie Electronic supplementary material The online version of this article (https://doi.org/10.1007/s13199-020-00684-x) contains supplementary material, which is available to authorized users. * M. Y. I. Houadria mikhou@hotmail.fr 1 Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branisovska 31, 370 05 Ceske Budejovice, Czech Republic 2 Animal Population Ecology, Animal Ecology I, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Universitätsstr 30, 95447 Bayreuth, Germany 3 Faculty of Science, University of South Bohemia, Branisovska 31, 370 05 Ceske Budejovice, Czech Republic 4 Forestry Department, Forest Research Centre, Sandakan, Sabah, Malaysia 5 Institute for Tropical Biology and Conservation, University Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia 6 Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany Symbiosis https://doi.org/10.1007/s13199-020-00684-x