Habitat Requirements of Rare Grasshopper Species in a Near-Natural Floodplain Ecosystem in the Northern Alps (Tyrol, Austria) by Josefine Höfler
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Degree Course Master in Environmental Management of Mountain Areas Habitat requirements of rare grasshopper species in a near-natural floodplain ecosystem in the Northern Alps (Tyrol, Austria) by Josefine Höfler Supervisor of the Free University of Bozen-Bolzano Prof. Dr. rer. nat. Stefan Zerbe Supervisor of the University of Innsbruck Dr. Georg Leitinger Year Degree Conferred: 2017/2018 + 1 Exam Date: 19/03/2019 Acknowledgements Als erstes möchte ich Hermann Sonntag danken, für den Themenvorschlag und die Möglichkeit, im wunderschönen Rißtal zu forschen. Vielen lieben Dank an Sina und Sebastian, für die Begleitung und Einweisung in das Gebiet sowie in die Flora und Fauna der Kiesbänke. Danke an die Weggemeinschaft Hinterriss-Eng für die Förderung meiner Arbeit. Danke an die Österreichischen Bundesforste und den Verband der Naturparke Österreichs für den Forschungsfond. Ein herzliches Dankeschön an Michael Reich, für die Zusendung relevanter Literatur, für den spannenden Austausch auf der Lech Exkursion, die vielen Mails und die Überlegungen zur Bryodemella tuberculata Population am Rißbach. Vielen Dank an Georg Leitinger und Erich Tasser für die geduldige Unterstützung und Hilfestellung bezüglich der statistischen Analyse. Danke Stefan Zerbe für die schnellen Antworten per Mail und die stete Bereitschaft, für Fragen verfügbar zu sein. Danke an Michael Schödl für die Übermittlung von Heuschreckenfunden am Bayerischen Teil des Rißbachs. Danke an die Abteilung Umweltschutz vom Land Tirol, besonders Walter Michaeler und Michael Haupolter, für die Beratung und die Versorgung mit Geräten. I Content List of figures ...................................................................................................... IV List of tables ........................................................................................................ V List of abbreviations ............................................................................................ VI Abstract ............................................................................................................. VII Zusammenfassung ........................................................................................... VIII 1. Introduction ................................................................................................... 1 2. Methods and Materials .................................................................................... 5 2.1 Study area ............................................................................................... 5 2.2 Study plots .............................................................................................. 8 2.3 Study species ......................................................................................... 11 2.3.1 Chorthippus pullus (Philippi, 1830) .................................................... 11 2.3.2 Tetrix tuerki (Krauss, 1876) .............................................................. 11 2.3.3 Bryodemella tuberculata (Fabricius, 1775) ......................................... 12 2.3.4 Psophus stridulus (Linnaeus, 1758) ................................................... 13 2.4 Data collection and processing ................................................................ 13 2.5 Vegetation mapping ............................................................................... 14 2.6 Habitats of the Annex I Habitats Directive ............................................... 16 2.7 Statistical Analysis .................................................................................. 17 3. Results ........................................................................................................ 20 3.1 Vegetation ............................................................................................. 20 3.2 Detected grasshoppers ........................................................................... 23 3.3 Statistical Analysis .................................................................................. 23 3.3.1 Bryodemella tuberculata ................................................................... 24 3.3.2 Chorthippus pullus ........................................................................... 26 3.3.3 Tetrix tuerki ..................................................................................... 27 3.3.4 Psophus stridulus ............................................................................. 27 4. Discussion ................................................................................................... 28 4.1 Bryodemella tuberculata ......................................................................... 28 4.2 Chorthippus pullus ................................................................................. 32 4.3 Tetrix tuerki ........................................................................................... 33 4.4 Psophus stridulus ................................................................................... 34 4.5 Management suggestions ....................................................................... 35 5. Conclusion ................................................................................................... 38 II References ......................................................................................................... 39 Attachments ...................................................................................................... 43 Annex I .......................................................................................................... 43 Annex II ......................................................................................................... 45 Annex III ........................................................................................................ 48 III List of figures Figure 1: The river Rißbach and its floodplain……………………………………………………2 Figure 2: Location of the study area in Tyrol and the nature park Karwendel…….5 Figure 3: Climate graph Hinterriss…………………………………………………………………….6 Figure 4: Daily runoff of the Rißbach in summer 2018…………………..……………………8 Figure 5: Location of the study plots and measure areas……………………………………9 Figure 6: Chorthippus pullus male……………………………………………………………………11 Figure 7: Tetrix tuerki…………………………………………………………………………………….11 Figure 8: Bryodemella tuberculata male……………………………………………………………12 Figure 9: Psophus stridulus male…..………………………………………………………………..13 Figure 10: Myricaria germanica on study plot 4…………..……………………………………….21 Figure 11: "Alpenschwemmlinge" Dryas octopetala and Campanula cochleariifolia…..21 Figure 12: Plant association Juncetum alpino-articulati…………………………………………22 Figure 13: Number of detected grasshoppers on the 23 study plots………………………..23 Figure 14: Boxplot of speckled grasshopper abundance and vegetation cover………….25 Figure 15: Typical habitat of Bryodemella tuberculata…………………………………………..28 Figure 16: Comparison of study plots 6 and 21……………………………………………………29 Figure 17: Bryodemella tuberculata female individual "swimming"..………………………31 Figure 18: Chorthippus pullus on rocky, sunny habitat…………………………………………32 Figure 19: Habitat of Tetrix tuerki at river Rißbach………………………………………………33 Figure 20: Comparison of habitats of Psophus stridulus…………………………………………34 Figure 21: Monitoring of Bryodemella tuberculata………………………………………………37 IV List of tables Table 1: Characteristics of the 23 study plots ....................................................... 10 Table 2: Conservation status of four grasshopper species ..................................... 13 Table 3: Datasheet on habitat characteristics ....................................................... 15 Table 4: Summary of the EU habitat types ........................................................... 16 Table 5: Transformation of values for the statistical analysis ................................. 18 Table 6: List of 18 independent variables for the multiple linear regressions .......... 18 Table 7: Results on the vegetation analysis on the 23 study plots…………………………20 Table 8: Output of multiple linear regression Bryodemella tuberculata ................... 24 Table 9: Output of multiple linear regression Bryodemella tuberculata females....... 25 Table 10: Output of multiple linear regression Bryodemella tuberculata males........ 26 Table 11: Output of multiple linear regression Chorthippus pullus ......................... 26 Table 12: Output of multiple linear regression Tetrix tuerki .................................. 27 Table 13: Output of multiple linear regression Psophus stridulus .......................... 27 Table 14: Counts of grasshopper species 24th - 30th of July 2018 ........................... 43 Table 15: Counts of grasshopper species 27th - 29th of August 2018 ...................... 44 Table 16: Data on habitat characteristics ............................................................. 45 Table 17: Results of the vegetation mapping of the 23 study plots ........................ 48 V List of abbreviations AIC……………………………………………………………………….... Akaike’s Information Criteria a.s.l……………………………………………………………………………………..……..Above sea level e.g……………………………………………………………………………………….…………..for example BIK…………………………………………………………………………..….Biotope type classification VI Abstract The Earth is facing a sixth mass extinction, given the extreme loss of biodiversity over the past decades on a global scale. Especially alarming is the decline of the insect fauna, which is mainly caused by habitat degradation. The loss of habitats is the main driver regarding the decline of several specialized insects inhabiting the