Biodiversity Changes in Vegetation and Insects Following the Creation of a Wildflower Strip
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Hochschule Rhein-Waal Rhine-Waal University of Applied Sciences Faculty of Communication and Environment Biodiversity changes in vegetation and insects following the creation of a wildflower strip A Case Study Bachelor Thesis by Johanna Marquardt Hochschule Rhein-Waal Rhine-Waal University of Applied Sciences Faculty of Communication and Environment Biodiversity changes in vegetation and insects following the creation of a wildflower strip A Case Study A Thesis Submitted in Partial Fulfillment of the Requirements of the Degree of Bachelor of Science In Environment and Energy by Johanna Marquardt Matriculation Number: 23048 Supervised by Prof. Dr. Daniela Lud Prof. Dr. Petra Blitgen-Heinecke Submission Date: 22.02.2021 Abstract With the Global Climate Change, the loss of biodiversity is one of the most current and biggest crises of today and the future. The loss i.e., the decrease of biodiversity, does not only have negative effects on vegetation and animals, but also on humans. If nature is doing well, people are doing well. In order to counteract the loss, this bachelor thesis attempts to increase plant and insect biodiversity at a specific location with insect-friendly seed mixtures and by measuring the change using comparison areas. Accordingly, the two research questions were addressed: (1) "How does plant-biodiversity change in the backyard and front yard on the seed mixture plot compared to plant-biodiversity in the backyard and front yard next to the seed mixture plot?" and (2) "How does insect-biodiversity change in the backyard and front yard on the seed mixture plot compared to insect-biodiversity in the backyard and front yard next to the seed mixture plot?" To answer these research questions and to obtain more suitable data, a wildflower strip was established in the backyard and one in the front yard, each with an adjacent reference field, to ensure equal environmental conditions and to detect changes in flora and fauna. Plants and insects were observed and documented during the flowering period in order to determine differences in biodiversity sizes afterwards. The comparison of the different biodiversity sizes shows that an increase in insect and plant biodiversity can be achieved by planting insect-friendly wildflower strips. As the increase of plant biodiversity also leads to the increase of insect biodiversity. Further research in the field of biodiversity enhancement could be done by collecting more measurement points of the coefficients at additional locations to extend the data set and to improve the applied method of this bachelor thesis. Also, the recordings could be repeated over a longer time period of several years. Keywords: Biodiversity, insect-friendly, species diversity, species richness, wildflower strip iii Table of Content Abstract III List of Abbreviations VII List of Formulas VII List of Symbols VII List of Figures VIII List of Tables IX-X 1. Introduction 1 1.1 What is biodiversity? 1 1.2 The loss of biodiversity 1-2 1.3 Measuring biodiversity 3 1.4 Motivation for this bachelor thesis 3-4 1.5 Hypothesis 4 1.6 Research questions 4 2. Material and Methods 5 2.1 Practical conditions 5-6 2.2 Metadata for the wildflower strips and their reference fields 6-7 2.3 Visual documentation of plants and insects 7 2.4 Identification of flora and fauna 7-8 2.5 The counting method 8-9 2.6 Determination of α-, β- and γ-diversity 9 2.7 α-diversity indices 9 2.7.1 Species richness 9 2.7.2 Shannon-Wiener index 10 2.7.3 Evenness 10 2.8 β-diversity indices 11 2.8.1 Simple-matching coefficient 11 2.8.2 Jaccard-coefficient 11 2.8.3 Soerensen-coefficient 12 2.8.4 Bray-Curtis coefficient 12 2.9 Presentation of the biodiversity 13 2.10 Correlation between recorded plants and insects 13 iv 3. Results 14 3.1 Observation and calculations 14 3.2 α-diversity of vegetation – Species list and species richness 14 3.2.1 Wildflower strip – Area 1 14 3.2.2 Reference Field 1 15 3.2.3 Wildflower strip – Area 2 15-16 3.2.4 Reference Field 2 16 3.2.5 Shannon – Wiener index and evenness of vegetation 16-17 3.3 β-diversity of vegetation 17-18 3.4 Visualization of the plant species-diversity 18-19 3.5 Plants origin and lifetime 20 3.5.1 Origin of the plants 20-21 3.5.2 Lifetime of the plants 21-22 3.6 Flora vegetation addition 22-23 3.7 α-diversity of recorded insects 24 3.7.1 Species list and species richness 24 3.7.2 Insect species list – wildflower strip – Area 1 24-25 3.7.3 Area 1 – species richness 25 3.7.4 Insect species list – Reference Field 1 26 3.7.5 Reference Field 1 – species richness 26 3.7.6 Insect species list – wildflower strip – Area 2 27 3.7.7 Area 2 – species richness 28 3.7.8 Insect species list – Reference Field 2 28-29 3.7.9 Reference Field 2 – species richness 29 3.7.10 Shannon-Wiener index and evenness of recorded insects 30 3.8 β-diversity of recorded insects 30-31 3.9 Visualization of the insect species-diversity 31-32 3.10 Fauna observation addition 33-34 3.11 Timing of the variety of insects recorded on the test fields 34-35 3.12 Correlation between flora and fauna 35-36 v 4. Discussion 37 4.1 The change of vegetation 37 4.1.1 α-diversity change of flora vegetation 37 4.1.1.1 Backyard 37 4.1.1.2 Front yard 37-38 4.1.2 β-diversity change of flora vegetation 38 4.1.3 The overall biodiversity of the vegetation 38-39 4.1.4 Negative side effects by the use of insect-friendly seed mixtures 39-40 4.1.5 Extra vegetation observation after completion of the observation phase 40 4.2 The change of fauna 41 4.2.1 α-diversity change of fauna 41 4.2.1.1 Backyard 41 4.2.1.2 Front yard 41-42 4.2.2 β-diversity change of fauna 42 4.2.3 The overall biodiversity of the recorded insects 43 4.2.4 Highlight on the insect order Hymenoptera 43-44 4.3 Correlation between plant- and insect-species 44-45 4.4 Methodology developed for this bachelor thesis 45 5. Conclusion 45-46 References 47-50 A. Appendix 51 A.1 Plant and insect catalog 51-71 A.2 Information about the origin and lifespan of plants 71-73 A.3 Recorded insects during the observation process 74-76 A.4 Calculations for flora 76-84 A.5 Calculations for fauna 84-98 A.6 Insect observation – mean value and standard deviation 99-101 Declaration of Authenticity 102 vi List of Abbreviations CBD = Convention on Biological Diversity BfN = Bundesamt für Naturschutz NABU = Naturschutzbund Deutschland BNatSchG = Bundesnaturschutzgesetz List of Formulas Page eq. 2.7.1 = Species richness 9 eq. 2.7.2 = Shannon-Wiener index 10 eq. 2.7.3 = Evenness 10 eq. 2.8.1 = Simple-matching coefficient 11 eq. 2.8.2 = Jaccard-coefficient 11 eq. 2.8.3 = Soerensen-coefficient 12 eq. 2.8.4 = Bray-Curtis similarity coefficient 12 eq. 2.8.5 = Bray-Curtis dissimilarity coefficient 12 eq. 2.10.1 = Measure correlation coefficient r according to Pearson 13 List of Symbols α = alpha β = beta γ = gamma S = Species richness H’ = Shannon-Wiener index E = Evenness Sm = Simple-matching coefficient Sj = Jaccard-coefficient Ss = Soerensen-coefficient Sbc = Bray-Curtis similarity Dbc = Bray-Curtis dissimilarity r = Measure correlation coefficient n = Number of individuals M = Mean value SD = Standard deviation vii List of Figures Figure 2.1: Environmental conditions around the test area 5 Figure 2.2: Urban and industrial conditions around the test area 5 Figure 2.3: Macro photograph of the insect-friendly seed mix 6 Figure 2.4: Wildflower strip – Area 1 6 Figure 2.5: Reference Field 1 6 Figure 2.6: Wildflower strip – Area 2 7 Figure 2.7: Reference Field 2 7 Figure 3.1: Shannon-Wiener index and evenness boxplot-diagram of vegetation 17 Figure 3.2: Venn-diagram of plant species-diversity 19 Figure 3.3: Origin – Pie chart; wildflower strip – Area 1 20 Figure 3.4: Origin – Pie chart; Reference Field 1 20 Figure 3.5: Origin – Pie chart; wildflower strip – Area 2 21 Figure 3.6: Origin – Pie chart; Reference Field 2 21 Figure 3.7: Lifetime – Pie chart; wildflower strip – Area 1 21 Figure 3.8: Lifetime – Pie chart; Reference Field 1 21 Figure 3.9: Lifetime – Pie chart; wildflower strip – Area 2 22 Figure 3.10: Lifetime – Pie chart; Reference Field 2 22 Figure 3.11: Origin – Pie chart of late bloomers 23 Figure 3.12: Lifetime – Pie chart of late bloomers 23 Figure 3.13: Insect species richness boxplot-diagram of wildflower strip – Area 1 25 Figure 3.14: Insect species richness boxplot-diagram of Reference Field 1 26 Figure 3.15: Insect species richness boxplot-diagram of wildflower strip – Area 2 28 Figure 3.16: Insect species richness boxplot-diagram of Reference Field 2 29 Figure 3.17: Shannon-Wiener index & evenness boxplot-diagram of recorded insects 30 Figure 3.18: Venn-diagram of insect species-diversity 32 Figure 3.19: Recorded types of the insect family Hymenoptera 33 Figure 3.20: Counted insects of the family Hymenoptera 34 Figure 3.21: Number of recorded insects, from the three observations 35 Figure 3.22: Correlation-diagram between plant- and insect-species 36 viii List of Tables Table 3.1: Plant species list & species richness – wildflower strip – Area 1 14 Table 3.2: Plant species list & species richness – Reference Field 1 15 Table 3.3: Plant species list & species richness – wildflower strip – Area 2 15-16 Table 3.4: Plant species list & species richness – Reference Field 2 16 Table 3.5: β-diversity coefficients for vegetation 18 Table 3.6: Plant species list & species richness – late bloomers 22-23 Table 3.7: Insect species list – wildflower strip – Area 1 24-25 Table 3.8: Insect species list – Reference Field 1 26 Table 3.9: Insect species list – wildflower strip – Area 2 27 Table 3.10: Insect species list