Focus Farm Wetland Study Focus Farm Wetland Study Acknowledgements This report has been produced for the Murrumbidgee Catchment Management Authority by the Charles Sturt University Project Team from the EH Graham Centre (EHGC) and the Institute of Land Water and Society (ILWS) at Charles Sturt University. The project team was: Dr Andrea Wilson (Freshwater Ecologist) - Project Manager from ILWS Dr Remy Dehaan (Spatial Data Analyst) - Project Manager from EHGC Dr Patricia Murray (Freshwater Ecologist) - Editor - ILWS Researchers Dr Catherine Allan (Envionmental Sociologist) - ILWS Helen Burns (Agricultural Liaison Officer) - EHGC Dr Max Finlayson (Wetland Ecologist) - ILWS Dr Iain Hume (Soil Scientist) - EHGC Dr Gaye Krebs (Animal Nutritionist) - Animal and Veterinery Sciences CSU Dr Daryl Neilsen (Freshwater Ecologist) - Murray Darling Freshwater Re- search Centre Dr Tom Nordblom (Economist) - EHGC Dr Skye Wassens (Freshwater Ecologist - Frogs) - ILWS Field Staff: Vanessa Griese (Field Assistant) - ILWS Allie Hendy - Honours Student (Plants and zooplankton) - ILWS Amelia Walcott - Honours Student (Frogs) - ILWS The Project Team would like to thank all staff and students who have contrib- uted to the collection, analysis and presentation of data for this report. We would also like to thank the landholders in the Coolamon and Hay regions who kindly volunteered their time and gave us access to their properties to conduct our research. Photographs throughout the report were taken by various team members, but a special thanks to Tom Nordblom for capturing many of the social interactions. ii Focus Farm Wetland Study Contents Executive Summary 1 Abstract 3 1. Background to the study 4 2. What are temporary rain-filled wetlands? 5 2.1 Physical characteristics 5 2.2 Filling frequency (hydroperiods) 5 2.3 Names for rain-filled wetlands 6 3. What is their value for biodiversity? 6 3.1 Plant diversity 6 3.2 Frogs 7 3.3 Zooplankton communities 7 4. Do rain-filled wetlands assist in catchment hydration? 8 5. Do wetland plants have value for livestock production? 8 6. What is the best management for biodiversity outcomes? 8 7. How do the land managers value these wetlands. 9 8. Indentification, assessment and prioritising wetlands 12 8.1 Identification of wetlands 12 8.2 Assessing and prioritising wetlands 12 9. Conclusions 13 10 References 13 Literature Review 15 1. Introduction 17 2. What are rain-filled wetlands? 17 3. Characteristics of temporary rain-filled wetlands 18 3.1 Hydrology 19 3.2 Ecological importance 19 4. Rain-filled wetlands in agricultural landscapes 21 4.1 Role in catchment hydration and flood mitigation 21 4.2 Role in nutrient retention and cycling 22 4.3 The costs of altered landscape on wetlands 22 5. Potential impacts of cropping on rain-filled wetlands 22 5.1 Effects on wetland vertebrates 23 5.2 Effects on wetland plant communities 24 5.3 Physico-chemical effects of cropping in wetlands 25 5.4 Effects on wetland macroinvertebrates 26 5.5 Effects on wetland egg and seed banks 26 iii Focus Farm Wetland Study 6. Potential impacts of livestock grazing on rain-filled wetlands 27 6.1 Overall effects of grazing 27 6.2 Effects of grazing on wetland vertebrates 28 6.3 Effects of grazing on wetland plant communities 29 6.4 Physico-chemical effects of grazing in wetlands 30 6.5 Effects of grazing on wetland macroinvertebrates 30 6.6 Effects of grazing on egg and seed banks in wetlands 31 7. Conclusions 31 8. References 32 Plants and zooplankton 37 1. Background 39 2. Study sites 40 2.1 Summary of wetland types studied 40 3. Methods 46 3.1 Rapid descriptive assessment 46 3.2 Field assessment of wetland plant communities 48 3.3 Soil Seed and Egg-bank assessment of wetland plant communities 49 3.4 Soil egg bank assessment of wetland zooplankton communities 52 4. Results 53 4.1 Field assessment of wetland plant communities 53 4.2 Soil Seed bank assessment of wetland plant communities 61 4.3 Combined field and soil seed bank data for wetland plant assessments 64 4.4 Soil egg bank assessment of wetland zooplankton communities 68 5. Discussion 72 5.1 Methods of assessments 72 5.2 Wetland contribution to regional biodiversity 72 5.3 Impacts of agricultural management 72 6. References 74 Appendix 1 Study activities for each study site 76 Appendix 2 Examples of percent cover classes for wetland vegetation 77 Appendix 3 Plant species emerging from seed bank 78 Appendix 4 Zooplankton species at each site 79 Frog recruitment 81 1. Background 83 2. Importance of rain-filled wetlands to frogs 83 3. Life history strategies 84 4. Methods 84 iv Focus Farm Wetland Study 5. Results 86 5.1 Wetland types 86 5.2 Species richness and abundance 86 5.3 Species distribution in wetland types 87 6. Discussion 88 7. References 90 Soils and Hydrology 93 1. Background 95 2. Wetland Soils of Coolamon 95 3. Wetland Soils of Hay 96 4. Wetland Classification 96 5. References 98 Coolamon Sites 99 Hay Sites 102 Nutritive Value of Wetland Plants 105 1. Background 107 2. Introduction 107 3. Materials and Methods 108 3.1 Collection of Plants 108 3.2 Laboratory Analyses 108 4. Results and Discussion 111 5. Conclusion 113 6. References 114 Socio-economic aspects 117 1. Introduction 120 2. Scoping the social and economic aspects of rain-filled wetlands 120 3. Method 120 3.1 Phase 1 - Focus farm discussions 121 3.2 Phase 2 – Case studies 123 4. Results 123 4.1 Hay district 123 4.2 A summary of the themes arising from the meetings and draft reports 124 4.3 Hay case studies summary 129 v Focus Farm Wetland Study Hay Case Study: Canegrass swamp management: 131 Hay Case Study: Black box depression/nitre goosefoot case study: 134 Hay Case Study: Black box depression/spike rush case study: 137 Coolamon district 140 Coolamon Case Study: Gilgais and mixed farming case study: 144 5. Discussion 152 5.1 Perceptions 153 5.2 Knowledge 154 5.3 External factors 154 5.4 Recommendations 155 References 156 Appendix 1- sample research information sheet 157 Using remote sensing to detect rain-filled wetlands 159 1. Introduction 161 2. Methods 162 3. Conclusion 168 4. References 168 Assessment and prioritisation framework 169 1. Introduction 171 2. How to identify rain-filled wetlands 172 3. Assessing rain-filled wetlands 177 4. Prioritisation 177 4.1 Individual wetland biota 178 4.2 Landscape connectivity 180 5. Conclusion 181 vi Executive Summary by Patricia Murray Institute of Land Water and Society - Charles Sturt University Focus Farm Wetland Study Acknowledgements The project managers, Andrea Wilson and Remy Dehaan wish to acknowledge the support and dedication of the team members and honours students: Editor: Patricia Murray; Researchers: Catherine Allan, Helen Burns, Remy Dehaan, Max Finlayson, Iain Hume, Daryl Neilsen, Tom Nordblom, Skye Wassens, Andrea Wilson. Honours Students: Allie Hendy, Amelia Walcott Field Staff: Janey Adams, Vanessa Griese. Sub-editor: Gordon Murray Also the support of: Murrumbidgee CMA staff for assisting in the Focus Farm Groups and locating wetlands in Hay and Coolamon regions; The land managers who participated in this study. Photographs were taken by a number of researchers, but Tom Nordblom took most of the photos used in this report. 2 Executive Summary Focus Farm Wetland Study Abstract This section summarises the information from the Focus Farm Wetland Study. The study concentrated on temporary rain-filled wetlands in the Coolamon and Hay regions of the Murrumbidgee catchment. The study, 2010 to 2011, resulted from field observations that rain-filled wetlands were relatively common in the Murrumbidgee catchment, but that a preliminary literature review showed little was known about their biodiversity value, present management and threats. To understand more about these temporary wetlands, the Murrumbidgee CMA com- missioned this study. The comprehensive literature review found that there were very few studies on temporary rain-filled wetlands in the world, let alone Australia. Overseas studies suggested that these temporary wetlands supported an important component of regional biodiversity and could be an important refuge for some amphibian species. They also were important for flood mitigation and accession of water into the soil and groundwater systems. The wetlands were shown to be affected by activities in the surrounding landscape, especially agricultural activities. The present study also found that rain-filled wetlands supported a rich diversity of plants and zooplankton, and were used for breeding by at least five frog species. The wetlands were hard to group ecologically because of their diverse characteristics. Twenty-four species of wetland plants were found to support moderate or better livestock growth. The wetlands contributed to catchment hydration by allowing water penetration into the soil profile and deeper groundwater. Their management differed depending on the predominate landuse surrounding the wetlands. In grazing context they were generally part of unimproved pas- tures and were not managed differently to the rest of the paddock. In Hay, where canegrass and/or shrubs were often present, they were especially valued for the livestock shelter they provided during extreme weather conditions. In the crop- ping context, again they were not managed differently to the rest of the paddock, but during wet times they were avoided during sowing or harvesting of crops to prevent bogging machinery. During dry times the wetlands were noticed to often produce a better crop than the rest of the paddock. The wetland managers participating in the study were keen to know more about these wetlands. They were surprised at the variety of plants and animals found. The scattered nature of these wetlands in some districts, like Coolamon, meant incentives such as for fencing were not necessarily the best option for actively engaging managers in conserving these wetlands.