Assessment of plant indicator and invasive species in Wetlands by Citizen Scientists. Guideline and Protocols

3 Assessments of plant indicator and invasive species in Wetlands by Citizen Scientists Guideline and Protocols Version 1.1 24.11.2025 Citation: Weigelhofer, G., Rosenberger, C., Feldbacher, E. (2025) Assessment of plant indicator and invasive species in Wetlands by Citizen Scientists. Guideline and Protocols. Horizon Europe Project Restore4Life (101112736). 10.5281/zenodo.17703928 4 Content CHAPTER 1: BACKGROUND ............................................................................................................................................................ 5 CHAPTER 2: HERBACEOUS PLANTS IN WETLANDS .............................................................................................................. 6 CHAPTER 3: IDENTIFYING PLANTS ............................................................................................................................................ 10 3.1. Outdoor protocol................................................................................................................................................................ 10 5 Chapter 1: Background Monitoring Ecosystem Services (ES) provided by wetlands is crucial for assessing the state of the wetlands, their changes over time, and the impacts of conservation and restoration measures. The engagement of non-experts as Citizen Scientists can support this ES monitoring by delivering large amounts of data otherwise not (easily) available. Additionally, Citizen Science helps raise awareness among local people about the significance of wetlands for human well-being, thereby enhancing citizens’ stewardship. In the Horizon Europe Project RESTORE4LIFE, 101112736 (https://restore4life.eu/ ), we have created a toolbox for monitoring ES of wetlands (Deliverable D3.5), covering both geospatial and on-the-ground methods (publicly available from Dec 2025on our webpage and Zenodo). One focus was on developing Citizen Science protocols for on-the-ground measurements that provide reliable and valuable data for wetland assessments. Various Citizen Scientists helped us test the developed protocols regarding their intelligibility, user-friendliness, and applicability before release. To assess the quality and explanatory power of the data collected by Citizen Scientists, we compared them with data collected by scientists using more advanced methods. The results of these quality checks can be found in our toolbox D3.5. The following topics were covered and published separately: (1) water body quality, (2) organic carbon storage in tree biomass and wetland soils, (3) plant diversity, and (4) recreational and educational services. Each published document consists of several parts: Citizen Scientists' protocol(s) for assessing data in the field; Citizen Scientists' protocol(s) for indoor analyses (if applicable); Citizen Scientists' protocol(s) for calculations (if applicable); and a guideline for scientists on further data processing. The current document addresses the identification of plant indicator and invasive species to determine plant diversity and status in wetlands. 6 Chapter 2: Herbaceous plants in wetlands Surveying herbaceous plant species provides valuable insights into the ecological conditions and health of habitats such as meadows, floodplains or peatlands. Different species have specific environmental preferences, so their presence and abundance reflect factors like soil nutrients, moisture, acidity, and light availability – all of which also affect carbon storage and ecosystem function. Citizen Science helps document the most common species along a transect by estimating their abundance using the Fisher scale. Identifying plants with the Flora Incognita app and photographing key features (whole plant, leaf, flower) ensures reliable species records and helps distinguish native from non-native plants. Equally, Citizen Scientists can record the occurrence of invasive plant species. Adding indicator values (based on Latin species names) offers further ecological interpretation. These values describe each plant’s typical environmental requirements, such as moisture, nitrogen or pH, and support a deeper understanding of habitat quality and possible changes due to climate change or land use. Flora incognita offers these values for each species under “traits”. You could also use the Ellenberg indicator values. Add the plant's Latin name to https://statedv.boku.ac.at/zeigerwerte/. Unfortunately, this platform is only available in German. Thus, we have added an English translation on the following pages. 7 ELLENBERG’S INDICATOR VALUES 8 9 REFERENCES ELLENBERG, H., WEBER, H.E., DÜLL, R., WIRTH, V., WERNER, W., PAULIßEN, D.: "Zeigerwerte von Pflanzen in Mitteleuropa", Scripta Geobotanica 18 (2.Auflage 1992). 10 Chapter 3: Identifying plants 3.1. OUTDOOR PROTOCOL MATERIALS:  10-20 m measuring tape or rope TASKS: 1. At each site, select a section 10-20 meters along the path and mark the ends with a ribbon. Take a photo of the site. 3. Walk along the path and determine the five to seven most common nonwoody species on both sides up to 2 m from the path. Estimate the abundances of these five species using the Fischer scale (shown below). Abundances according to the Fischer scale (1986): Symbol Abundance Areal coverage 1 Ra re , 1-2 plants per species < 5 % 2 210 plants per species < 10 % 3 Common, >10 plants per species <20 % 4 Very common 20-50% 5 Dom inating 50-10 0 % 4. Identify each species using the "Flora Incognita" App. Take a picture of the entire plant, the leaf, and the flower (if present). Check the identification by comparing it to the plant description in the app. 5. Then, look under “traits”. Here you find information on the species' distribution, protection status, and habitat preferences. Note whether the species is native or not (neophyte). Note the numbers of the indicator values Nutrients, Moisture, Light, Temperature, and Soil Reaction (pH). These indicators describe the plant’s habitat preferences. The higher the number, the more light, soil moisture, nutrients, temperature, and pH the plant prefers or tolerates. 11 We appreciate your support! Your data provide information on the wetland vegetation, plant diversity, and the health of the ecosystem. This helps to develop management strategies to restore and protect the wetland.