Irish Ants (Hymenoptera, Formicidae): Distribution, Conservation and Functional Relationships Submitted by: Dipl. Biol. Robin Niechoj Supervisor: Prof. John Breen Submitted in accordance with the academic requirements for the Degree of Doctor of Philosophy to the Department of Life Sciences, Faculty of Science and Engineering, University of Limerick Limerick, April 2011 Declaration I hereby declare that I am the sole author of this thesis and that it has not been submitted for any other academic award. References and acknowledgements have been made, where necessary, to the work of others. Signature: Date: Robin Niechoj Department of Life Sciences Faculty of Science and Engineering University of Limerick ii Acknowledgements/Danksagung I wish to thank: Dr. John Breen for his supervision, encouragement and patience throughout the past 5 years. His infectious positive attitude towards both work and life was and always will be appreciated. Dr. Kenneth Byrne and Dr. Mogens Nielsen for accepting to examine this thesis, all the CréBeo team for advice, corrections of the report and Dr. Olaf Schmidt (also) for verification of the earthworm identification, Dr. Siobhán Jordan and her team for elemental analyses, Maria Long and Emma Glanville (NPWS) for advice, Catherine Elder for all her support, including fieldwork and proof reading, Dr. Patricia O’Flaherty and John O’Donovan for help with the proof reading, Robert Hutchinson for his help with the freeze-drying, and last but not least all the staff and postgraduate students of the Department of Life Sciences for their contribution to my work. Ich möchte mich bedanken bei: Katrin Wagner für ihre Hilfe im Labor, sowie ihre Worte der Motivation. Katja Scholz und Alice Mazurek für ihre stetige Hilfsbereitsschaft und Hilfe, meinen Eltern Monika und Karl-Heinz Niechoj, sowie meiner Schwester Sandy Marschke für ihre jahrelange Unterstützung. iii Thesis Overview This thesis consists of six chapters. Chapter 1 provides a general introduction to this work within the context of the wider national soil biodiversity project CréBeo. Furthermore ants, earthworms and the use of stable isotopes measurements as a tool for the investigation of trophic ecology of ants and other organisms are introduced. Chapter 2 presents the baseline survey undertaken for ants. An overview of the outcomes of surveys on other soil organisms is also provided. Chapter 3 provides information on the distribution of Irish ants in the Counties Clare, Galway and Limerick. It identifies species and habitats worthy of conservation and gives recommendations for the conservation of ants and suggests situations where information on ants should feed into conservation plans for other taxa. Chapter 4 investigates the relationships between long established colonies of the soil dwelling ant Lasius flavus (F.) and the earthworm community in old limestone grasslands. Chapter 5 presents new information on the trophic interactions of Irish ants based on the use of stable isotopes. It includes not just species of three native genera from a limestone pavement, a notably rare habitat in the European context, but also addresses ontogenetic, temporal and ecosystem aspects of this topic. Chapter 6 provides an overall conclusion for the thesis. iv Table of Contents Title Declaration.............................................................................................................. ii Acknowledgements/Danksagung...........................................................................iii Thesis Overview .................................................................................................... iv Table of Contents .................................................................................................... v List of Abbreviations ............................................................................................ vii List of Figures ........................................................................................................ ix List of Tables ......................................................................................................... xi Chapter 1: General Introduction ........................................................................... 12 1.1. CréBeo – The Irish soil biodiversity and protection project......... 12 1.2. Ants ............................................................................................... 15 1.3. Earthworms ................................................................................... 16 1.4. Stable isotopes as a tool for the investigation of trophic relationships in ecology .................................................................................... 17 1.5. References..................................................................................... 20 Chapter 2: Baseline data on Irish soil organisms: Ants ........................................ 24 2.1. Abstract ......................................................................................... 24 2.2. Introduction................................................................................... 24 2.3. Material and Methods ................................................................... 24 2.4. Results........................................................................................... 28 2.5. Discussion ..................................................................................... 32 2.6. Conclusions and outlook............................................................... 36 2.7. References..................................................................................... 37 Chapter 3: Conservation........................................................................................ 39 3.1. Abstract ......................................................................................... 39 3.2. Introduction................................................................................... 39 3.3. Material and methods.................................................................... 44 3.4. Results........................................................................................... 47 3.5. Conclusions and outlook............................................................... 55 3.6. References..................................................................................... 58 Chapter 4: Do ants alter earthworm community structure and soil functioning in grassland ecosystems? ...................................................................................... 61 4.1. Abstract ......................................................................................... 61 4.2. Introduction................................................................................... 61 4.3. Material and Methods ................................................................... 63 4.4. Results........................................................................................... 65 4.5. Discussion ..................................................................................... 74 4.6. Conclusion and outlook................................................................ 76 4.7. References..................................................................................... 77 Chapter 5: Trophic relationships of ant species (Formicidae) in an Irish limestone pavement ............................................................................................................... 80 5.1. Abstract ......................................................................................... 80 5.2. Introduction................................................................................... 80 5.3. Materials and Methods.................................................................. 81 5.4. Results........................................................................................... 83 5.5. Discussion ................................................................................... 101 5.6. Conclusion and outlook.............................................................. 106 v 5.7. References ...................................................................................108 Chapter 6: Overall discussion and conclusions...................................................111 Appendix 1.1. Presence and absence of ants on sites of the baseline survey......114 Appendix 1.2. Data set for chapter 3...................................................................118 Appendix 1.3. Soil physical and chemical data for Chapter 4 ............................120 Appendix 2. Manuscript submitted to the European Journal of Soil Biology.....133 Appendix 3. Manuscript in preparation...............................................................175 vi List of Abbreviations AF Arable Fields All_chl Allolobophora chlorotica AMF Arbuscular Myccorhizal Fungi ANOVA analysis of variance Apo_cal Aporrectodea caliginosa Apo_lon Aporrectodea longa Apo_ros Aporrectodea rosea B Barrigone BW Broadleaf Woodland C3 three-carbon Compound C4 four-carbon Compound CAM Crassulacean Acid Metabolism CF-IRMS Continuous Flow-Isotope Ratio Mass Spectrometry CG Calcareous Grassland Co. County CW Coniferous woodland CY Urban (habitat), City e.g. exempli gratia EA-IRMS Elemental Analyser-Isotope Ratio Mass Spectrometry EEA European Environment Agency EPA Environment Protection Agency et al. et alia EW, Ew Earthworm(s) F Female Alata(e) F Foynes F. Fabricius FB Ferrybridge fig. Figure For_lem Formica lemani GIS Geographical Information System GPS Global Positioning System I introduced