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THE IMPACT OF PINE PLANTATIONS AND ALIEN INVERTEBRATES ON NATIVE FOREST AND FYNBOS INVERTEBRATE COMMUNITIES IN TABLE MOUNTAIN NATIONAL PARK CHARMAINE JANET UYS Town Cape Thesis Presentedof for the Degree of DOCTOR OF PHILOSOPHY in the Department of Zoology UNIVERSITY OF CAPE TOWN University February 2012 Supervised by: Prof. Mike D. Picker Co-supervised by: Prof. Charles L. Griffiths The copyright of this thesis vests in the author. No quotation from it or information derived from it is to be published without full acknowledgementTown of the source. The thesis is to be used for private study or non- commercial research purposes only. Cape Published by the University ofof Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author. University DECLARATION I hereby: (a) grant the University free license to reproduce the above thesis in whole or in part, for the purpose of research; (b) declare that: (i) the above thesis is my own unaided work, both in conception and execution, and that apart from the normal guidance of my supervisors, I have received no assistance apart from that stated in the acknowledgements; (ii) neither the substance nor any part of the thesis has been submitted in the past, or is being, or is to be submitted for a degree at this University or any other University. (iii) I am now presenting the thesis for examination for the Degree of PhD. Signed: ……………………...... Date: ….....…………………. Charmaine Uys (PhD candidate) 2 The impact of pine plantations and alien invertebrates on native forest and fynbos invertebrate communities in Table Mountain National Park Charmaine Uys (February 2012) ABSTRACT While the Cape Peninsula (South Africa) is renowned for its exceptional plant and invertebrate diversity and endemism, extensive alien plant invasions and exotic pine plantations threaten and reduce native species richness. This study frames invasion ecology theory in a conservation context, and examines the impact of planting and felling pine on litter invertebrate communities, by comparing invertebrate diversity between pine plantations and native vegetation. Impacts of the worst invasive alien invertebrate (Argentine ant, Linepithema humile) and other alien invertebrate species are investigated. This is one of the first attempts to inventory and quantify impacts of non-ant alien invertebrates in Table Mountain National Park. The entire ground-dwelling invertebrate community was sampled at 31 sites in summer 2008/2009, using soil cores, leaf litter samples, pitfall traps, sugar-baited ant traps and decayed logs. A total of 112 404 individuals, representing 728 species (10 classes and 38 orders), including nine Cape Peninsula endemic and 19 alien species, was collected. Pine plantations supported lower species richness and abundance, and different community assemblages, compared to Afrotemperate forest, but similar species richness to fynbos. This supports previous local studies and global trends. Pine plantations shared fewer species with fynbos than forest, and negatively affect fynbos-specialist invertebrates, because afforestation reduced available fynbos habitat. Alien species richness was similar across habitats. Argentine ants, like most other alien species identified, were present in all habitats. The impact of Argentine ant invasion on native ant communities was evaluated using species richness and community composition analyses, species co-occurrence patterns (C-score), and the functional group approach. The comparative approach adopted provided no evidence for displacement, impoverishment, or community disassembly. No clear impacts of the 18 non-ant alien species on the abundance, species richness, or community composition of corresponding native taxa were detected. Disturbance history offers a more parsimonious explanation for the trends observed, particularly in fynbos. However, carnivorous molluscs require careful monitoring, given their abundance and known impacts elsewhere. Using a reiterative process and IndVal, two ant species (Pheidole capensis and Camponotus bertolinii) were selected as ecological indicators of restoration progress in fynbos following clear-felling of pine. Ants similarly have application for monitoring in other Mediterranean-type ecosystems impacted by invasive pines. 3 CONTENTS DECLARATION ......................................................................................................................... 2 ABSTRACT ................................................................................................................................ 3 CONTENTS ............................................................................................................................... 4 ACKNOWLEDGEMENTS .......................................................................................................... 6 CHAPTER 1. INTRODUCTION .................................................................................................. 7 Setting the scene .................................................................................................................... 7 Ecological impacts of pine invasions in South Africa ............................................................... 8 Ecological impacts of invertebrate invasions in South Africa ................................................... 9 Implications of felling pine for invertebrate communities ........................................................10 Broad aims and objectives .....................................................................................................10 CHAPTER 2. STUDY SITES AND SAMPLING METHODS ......................................................12 Study area .............................................................................................................................12 Study sites .............................................................................................................................17 Pilot study ..............................................................................................................................19 Sampling methods .................................................................................................................23 CHAPTER 3. THE INFLUENCE OF ALIEN PINE PLANTATIONS ON INVERTEBRATE DIVERSITY AND SPECIES TURNOVER ON THE CAPE PENINSULA....................................28 Introduction ...........................................................................................................................28 Methods ................................................................................................................................31 Results ..................................................................................................................................36 Discussion .............................................................................................................................56 CHAPTER 4. IMPACTS OF ARGENTINE ANTS AND OTHER ALIEN INVERTEBRATES ON NATIVE GROUND-DWELLING INVERTEBRATES ON THE CAPE PENINSULA ....................69 Introduction ...........................................................................................................................69 4 Methods ................................................................................................................................78 Results ..................................................................................................................................82 Discussion ........................................................................................................................... 110 CHAPTER 5. ANTS AS INDICATORS OF RESTORATION PROGRESS FOLLOWING CLEAR- FELLING OF PINE PLANTATIONS IN A MEDITERRANEAN-TYPE ECOSYSTEM ............... 120 Introduction ......................................................................................................................... 120 Methods .............................................................................................................................. 127 Results ................................................................................................................................ 131 Discussion ........................................................................................................................... 139 CHAPTER 6. IMPLICATIONS OF PLANTING AND FELLING PINE FOR GROUND-DWELLING INVERTEBRATES ON THE CAPE PENINSULA .................................................................... 144 Implications of planting pine for ground-dwelling invertebrates ............................................ 144 Implications of alien invertebrate species invasions for native invertebrate taxa .................. 145 Implications of felling pine for ground-dwelling invertebrates ............................................... 146 Cautionary notes ................................................................................................................. 149 Conclusions ......................................................................................................................... 151 The way forward .................................................................................................................. 152 REFERENCES ....................................................................................................................... 154 APPENDIX A. Study sites ....................................................................................................... 182 APPENDIX B.

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