(Bitou Bush) on Coastal Ecosystem Processes
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University of Wollongong Research Online University of Wollongong Thesis Collection 1954-2016 University of Wollongong Thesis Collections 2004 The impact of Chrysanthemoides monilifera spp. rotundata (bitou bush) on coastal ecosystem processes Elizabeth A. Lindsay University of Wollongong Follow this and additional works at: https://ro.uow.edu.au/theses University of Wollongong Copyright Warning You may print or download ONE copy of this document for the purpose of your own research or study. The University does not authorise you to copy, communicate or otherwise make available electronically to any other person any copyright material contained on this site. You are reminded of the following: This work is copyright. Apart from any use permitted under the Copyright Act 1968, no part of this work may be reproduced by any process, nor may any other exclusive right be exercised, without the permission of the author. 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For further information contact the UOW Library: [email protected] The impact of Chrysanthemoides monilifera spp. rotundata (bitou bush) on coastal ecosystem processes A thesis submitted in fulfilment of the requirements for the award of the degree of Doctorate of Philosophy from the University of Wollongong by Elizabeth A. Lindsay B. Med. Chem (Hons) Department of Biological Sciences 2004 Thesis Certification Certification I, Elizabeth Lindsay, declare that this thesis, submitted in fulfilment for the requirements for the award of Doctor of Philosophy, in the Department of Biological Sciences, University of Wollongong, is wholly my own work unless otherwise referenced or acknowledged. The document has not been submitted for qualifications at any other academic institution. Elizabeth A. Lindsay November 2003 Table of Contents Page Number List of Tables i List of Figures iv List of Abbreviations x Abstract xi Acknowledgments xiv CHAPTER 1: Introduction 1 Plant invasions in Australia 2 Bitou bush 2 Control techniques and their implications 7 Litter decomposition 9 Invertebrates and weeds 11 Invertebrates and decomposition 13 Aims 14 Thesis format 15 CHAPTER 2: The affect of Chrysanthemoides monilifera ssp. rotundata invasion on decomposition rates and environmental parameters Introduction 17 Methods 19 Study area 20 Decomposition study 21 Statistical analysis 22 Leaf structure 24 Soil moisture 24 Soil surface temperature 25 Light transmittance 25 Results 26 Decomposition study 26 Decomposition constants 29 Leaf quality 32 Environmental Differences 33 Discussion 39 Environmental parameters 39 Decomposition rates 41 Leaf quality 42 Leaf litter invertebrates 43 Site variation 44 Conclusion 46 CHAPTER 3: Nutrient cycling and litterfall in coastal areas invaded by Chrysanthemoides monilifera ssp. rotundata Introduction 48 Methods 51 Study Sites 51 Soil nitrogen 52 Soil pH 53 Bulk density 53 Litterfall 54 Leaf litter layer 55 Leaf nutrient analysis 55 Nutrient loss from decomposing leaves 56 Results 57 Soil nitrogen 57 Soil properties 59 Leaf fall and ground litter layer 61 Leaf nutrients 65 Nutrient flux from decomposing litter 67 Discussion 74 Litterfall and the litter layer 74 Nutrient loss from leaf litter 76 Senescence 79 Soil nitrogen 81 Soil properties 83 Effect of nutrient enrichment 84 Implications for regeneration 84 Conclusions 85 CHAPTER 4: The affect of Chrysanthemoides monilifera ssp. rotundata invasion on coastal leaf litter invertebrates Introduction 87 Methods 89 Study Sites 89 Invertebrate sampling 90 Data analysis 91 Results 93 Invertebrate abundance 94 Taxa and species composition 105 Temporal variation 109 Discussion 111 Litter quality 113 Temporal variation 114 Spatial variation 114 Conclusions 116 CHAPTER 5: The impact of the herbicide Roundup® Biactive™ (glyphosate), on leaf litter invertebrates within bitou bush infestations Introduction 118 Methods 121 Study sites 121 Invertebrate sampling 122 Change in abundance 122 Community composition 123 Results 125 Changes in abundance of taxa 126 Community composition 129 Discussion 133 Direct toxic effects 133 Indirect effects 134 Rainfall and temperature 135 Conclusions 137 CHAPTER 6: Conclusions 138 REFERENCES 142 APPENDIX Newton iteration technique 168 i List of Tables Page number Table 2.1: Summary of the soil and vegetation characteristics of each field 20 site. Table 2.2: Summary of a four-factor ANOVA for each field site for the 28 mean mass lost of C. monilifera and native leaves with time. The leaves were either in coarse or fine litterbags (Bag type) in a C. monilifera infested area or a native un-infested area (Weed) Table 2.3. The mean percent original mass remaining for all time periods, 29 for each leaf type within each habitat at each site. Table 2.4. The decomposition constants (k) for the single and double 30 exponential decay models. The regression coefficients (R2) for the double exponential decay model were calculated from observed vs. predicted values. Table 2.5. The mean initial leaf carbon and nitrogen concentrations of each 32 species, and the native leaf mixture, ± one standard error Table 2.6: The percent moisture and physical leaf parameters for each 33 species. Table 2.7: Summary of a two-factor ANOVA, performed to determine the 34 difference in soil moisture between the C. monilifera infested areas and native un-infested areas at each site. Table 2.8: Summary of a three-factor ANOVA performed to determine the 36 difference in soil surface temperatures at day (6am-5pm) and night (6pm- 5am) within the C. monilifera invaded and native area at each site. Table 2.9: Summary of a two-factor ANOVA performed to determine the 38 difference in percent light transmittance between C. monilifera infested and native areas at each site ii Table 3.1: Summary of the two factor ANOVA results performed to determine 57 the difference in total soil nitrogen concentration between native and C. monilifera invaded areas at each site. P<0.05 significance level. Table 3.2: Summary of the two factor ANOVA results performed to determine 58 the difference in soil ammonia and nitrate concentration between native and C. monilifera invaded areas at each site. P<0.05 significance level. Table 3.3. Summary of a two factor ANOVA performed to determine the 60 difference in soil bulk density between native and C. monilifera areas at each site. P<0.05 significance level. Table 3.4: Summary of the three factor ANOVA performed to determine the 64 difference in total ground litter weight per metre squared and leaf weight per metre squared between native and C. monilifera (weed) invaded areas. P<0.05 significance level Table 3.5: The nutrient content of green leaves (± one standard error) and the 66 carbon to nutrient ratios. Table 3.6: The nutrient content of abscised leaves (± one standard error) and 66 the carbon to nutrient ratios. Table 3.7: The approximate annual nutrient input from the leaf fall from the 67 three dominant species in the native areas and C. monilifera in the weed infested areas. Table 4.1: The number of beetle morphospecies identified. Selected 92 morphospecies were first classified to family or superfamily before being identified further. iii Table 4.2: Summary of the ANOVA for total abundance, number of taxa and 95 abundance of certain orders and classes. P>0.05 significance level. Significant results are in bold. Table 4.3: Summary of the ANOVA for total abundance per gram of litter and 97 total number of taxa per gram of litter. P>0.05 significance level. Significant results are in bold. Table 4.4: The ANOSIM results for each site testing for differences between 97 native and C. monilifera areas at each collection time. Data was either square root or presence/ absence transformed. P=0.05 significance level. Table 4.5: The average dissimilarity between the invertebrate assemblages 99 within the native and C. monilifera areas of each site. SIMPER analysis was not performed on presence/absence data for Anna Bay as the ANOISM was not significant. Table 5.1: Summary of the unreplicated repeated measures ANOVA for the 125 abundance of each group analysed. Significant values are in bold. P<0.05 significant level. Table 5.2: Results of the analysis of similarity, comparing the before impact 130 time with the four after impact sampling times, for impact and control sites. Data were square root transformed. iv List of Figures Page number Figure 1.1: The distribution of C. monilifera spp. rotundata in Australia. 3 Map adapted from Weiss et al. (1998). Figure 1.2: a. Native coastal shrubland at Warrain Beach N.S.W, b. Bitou 6 bush infestation on Comerong Island, c. Bitou bush infestation at Anna Bay N.S.W d. A bitou bush flower. Figure 2.1: The mean percentage of the original weight remaining in small 27 and large litterbags in C. monilifera (bitou) and native un-infested areas, through time pooled across all sites. Error bars are one standard error. Figure 2.2. The fitted curves from a, the single exponential decay model for 31 the native leaf mix litterbags and b, the double exponential decay model for C.