Air Quality: Lichens as Bioindicators of Air Pollution

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Grant Agreement number: 226646 -CP- 1-2005-1-IE-COMENIUS-C21 (2005-3264) Air Quality: Lichens as Bioindicators of Air Pollution Subject: Biology Grade level: Upper secondary schools Anticipated time:

1 Grant Agreement number: CP IE-COMENIUS-C21 ( ) Air Quality: Lichens as Bioindicators of Air Pollution Subject: Biology Grade level: Upper secondary schools Anticipated time: 8 hours (lessons and outdoor activities) Developer: L. Brancaleoni, O. De Curtis, U. Thun Hohenstein, M.C. Turrini Abstract In this module students, working in groups, collect data about lichens, widely used as environmental indicators (bio-indicators) to check the quality of air. Air pollution is assessed by calculating the index of lichen biodiversity. This module brings together observations and data collection in the open air with data elaboration in the classroom. Data collection made in the open air will help students improve their skills in observing nature, and the use of handheld technologies will help them measure variables in a scientific way. The heritage site where the module was tested was one of the larger parks of the city of Ferrara which has been a UNESCO Heritage site since The city of Ferrara is located in the Æmilia Romagna Region, north-east Italy. Institution: Biology and Evolution Department, University of Ferara Country: Italy

2 CENTRAL IDEA AND DRIVING QUESTIONS What is air quality in our city? Can we use lichens as bioindicators of air quality? DURATION 8 hours: 3 hours for the preparation lesson in the classroom (indoors) 2 hours for the outdoor activity (outdoors) 3 hours for the post-field work in classroom (indoors) LEVEL Upper secondary schools PEDAGOCICAL FRAMEWORK Documentation is both a process and a product involving discovery, extension, reflection and communication (Glass, Baker, Ellis, Bernstone, & Hagan, 2007). Besides, it is a tool to make learning concrete and observable (Capello, 2007). Advanced technologies involved in the study of science are a new tool of documentation (Lee, Hatherly, & Ramsey, 2002; MacNaughton & Williams, 2004; Fleer et al., 2006). This module proposes the study of air quality using living organisms as bioindicators. Botanical knowledge therefore becomes a profitable tool to verify, in a simple and inexpensive way, how pure the air we breathe is. Lichens are living organisms that can indicate air quality by simply counting the presence of different species in a grid area placed on a tree. Repeating the same sampling on a number of trees will lead to the lichen biodiversity index, i.e. an index of air quality. Then the sample area will be displayed on a georeferred map and, by calculation made by the GIS software, a colour scale shows the characteristic of the air and how these characteristics vary in the area. The module does not require specific knowledge of the lichen species because one only needs to distinguish that one lichen is different from the other, based on morphology and colour. At any rate, the module is also useful to study directly in the field the morphology and the features of tallophytes and cormophytes. PREREQUISITE KNOWLEDGE It would be useful for the students that have to apply this module to have notions about algae, fungi and trees and notions about air pollution. Moreover, it is necessary to know how to use GIS (Geographic Information Systems) software.

3 BACKGROUND KNOWLEDGE A lichen is a symbiosis of two organisms. These are a fungus (the mycobiont) and an alga (or a cyanobacterium, the photobiont). The photobiont produces food for the fungus from photosynthesis and the fungus protects the alga by retaining water and providing mineral nutrients. Most lichens assume the outer shape of the fungal partner. Some lichens look like leaves (foliose lichens), and others cover the substratum like a crust (crustose lichens) or have shrubby forms (fruticose lichens). A typical foliose lichen thallus is formed by four layers. The uppermost layer (the cortex) is formed by fungal hyphae building a protective outer layer. Beneath the cortex there is an algal layer composed of algal cells embedded in rather densely interwoven fungal hyphae. Beneath this layer there is the medulla, a third layer of loosely interwoven fungal hyphae without algal cells. The lower cortex resembles the upper surface and consists of densely packed fungal hyphae and often presents root-like fungal structures known as rhizines, which attach the thallus to the substrate. Many lichens reproduce asexually with soredia, small groups of algal cells surrounded by fungal filaments (no cortex), and by isidia, extensions of the surface of the thallus for wind dispersion. Many lichen fungi also reproduce sexually producing spores in apothecia, perithecia as normal fungi. Since lichens are poikilohydric organisms, without true organs, their hydratation status is related to the humidity of the air (upon which their mineral nutrition depends). Because of these characteristics, lichens are very sensitive to gaseous pollutants, particularly sulphur dioxide, and are widely used throughout the world as pollution indicator organisms. Lichen characters measured in air pollution studies include observations of population changes and morphological effects because, due to the pollutants in the air, chlorophyll is destroyed and consequently photosynthesis is inhibited. MATERIALS - Palm hand-held computer or laptop - GPS - Folding rule or tape measure - Hand-made grid (the grid is a series of 5 squares of 10x10 cm) (see Appendix 1) - Book for lichen identification (if required) - Swiss army knife and small paper bags for collection of lichens (if required; see paragraph on extensions) - digital camera

4 - GIS software - Georeferred map of the area where the study will be done CONTEXT This module can be developed in any area with trees. It is possible to choose small areas such as the school garden, the municipal park, or larger areas such as the whole city, the countryside, woodlands and so on. We chose one of the larger parks of the city (Parco Massari). The centre of Ferrara was inscribed on the UNESCO World Heritage list as a shining example of a Renaissance city that has retained its centre virtually intact. The criteria underlying this choice were as follows 1 - The Este dynasty residences in the Po Delta illustrate the influence of Renaissance culture on the natural landscape in an exceptional manner. 2 - The Po Delta is an outstanding planned cultural landscape which retains its original form to a remarkable extent ( Parco Massari The city centre has two green areas of considerable extension and a lot of private gardens, but in the outskirts there is a chemical factory that may negatively affect the quality of the air; such effects are promptly recorded by the lichens that live on the bark of the trees in the town and around it.

5 INSTRUCTIONAL ACTIVITIES Lesson 1 Indoors (Preparatory) Duration 3 hours Goals Students acquire basic knowledge about lichens and prepare simple tools to be used in the park for applying the method. They gain confidence with the handheld technological tools, and are informed about the heritage site where they will go and how to behave properly. The teacher checks ideas and preconceptions and/or misconceptions that students have on how to measure air pollution. Then s/he illustrates the method based on the presence of lichens living on the tree bark, using a video that shows this method. Students have an introduction to the use of Palm hand-held computers and GPS. Students gain confidence with lichens based on their colours and shapes, using pictures and/or manuals or by surfing the internet. Students prepare the grid (see appendix 1), the check-list of lichens (see appendix 2) and the spreadsheet for the calculation of the Lichen Biodiversity Index (LBI) (see appendix 3). Students record information about the heritage site where the experiment will be carried out. Lesson 2 Outdoors Duration 2 hours Goals Students check and record lichen frequency in the study area to examine the level of air pollution. The collection of LBI will improve students skills in observing nature and their precision in measuring parameters accurately and scientifically. Group work will help their cooperation skills.

6 Proper behaviour students will improve their consciousness as citizens in good standing. If the module is to be carried out in a protected area, the teacher must make all the necessary applications for permits to visit and/or collect samples. Students are divided in small groups so that all of them can participate in the collection of the data. Every group is responsible for the data of one survey station. Every group checks at least three trees in order to calculate the LBI of the station. Chosen trees must have subneutral bark e.g. lime (Tilia) or oak (Quercus), while trees with sour bark (e.g. conifers) are preferably avoided. The tree should have the following characteristics - circumference of at least 60 cm; - trunk inclination <10 ; - no evident trouble phenomena. Students then put the grid on the tree at about 1 metre up, more or less exposed to a cardinal point (N, E, S, W). Damaged areas of the bark and areas with excessive coverage of mosses or algae must be avoided. Grid on the tree To repeat the study (e.g. in the following years), the following must be recorded - the location of the tree by the GPS; - the exposure of the grid, with the aid of GPS or a compass; - the quote of the grid referred to the base of the trunk; - the circumference of the trunk where the grid is put on.

7 Every tree is also photographed for proper identification at any time. Students therefore record the presence of the lichen species in the 5 grid parts (frequencies from 0 to 5). If the same lichen specimen is present in more than one unit, its frequency value is the same as the number of units where it is present (see fig. 1 at the end of the module). Lichens are distinguished according to their morphology and colour or species (if known). If needed for the identification of the species in the laboratory, students may pick up a small sample and take pictures of lichens. For each tree checked, the Lichen Biodiversity Index (LBI) is the sum of lichen frequencies counted for every cardinal point, while the LBI of the station is the average of the LBI of all the trees checked in the survey station. Calculations (vide Appendix 3) may be made directly in the field or later in the classroom using the spreadsheet drawn up during the preparatory lesson. After completion and the counting of lichens has been recorded, the teacher leads the students in a brief discussion and analysis of the data which they have after collecting. Lesson 3 Indoors (Follow-up) Duration 3 hours Goals Students calculate and interpret the Lichen Biodiversity Index as an indirect index of air purity and display the result in a map through GIS technology. They will understand the central idea of the module and answer the driving questions. In the classroom students display the georeferred map of the heritage site with the sampled areas, using the GIS software. They load the coordinates of checked trees and calculate the LBI (if not already done in the field). GIS can identify every checked point using different colours based on the LBI value, thus having the chance of immediately seeing where the air is clean or not (vide Figure 2). Showing the image of the map with LBI on a screen, the teacher can lead students in a discussion of the results obtained. Some topics of the discussion might be the safety of living beings in connection with the quality of the air; different methods to analyse the quality of the air found surfing the internet, the distance between the most polluted point and the hypothesised polluting source. Students can compare data collected from different trees and in different areas of the town. If necessary, students may observe lichen samples with microscopes and identify the species by the use of manuals and/or the internet.

8 Objectives By the end of the module students will understand - how air quality influences living organisms; - how some living organisms can be used to study air quality; - how to study air pollution; - the direct influence of human activity on the environment. Students will learn how to use Palm hand-held computers, GPS, and GIS technology. POSSIBLE EXTENSIONS Students may compare the calculated LBI with the official data recorded by environmental agencies. They can send their results to the local environment agency, urging some countermeasures if needed. Students can repeat the same survey in different places, closer to and farther from potential sources of air pollution. Students can compare different techniques (direct and indirect) for monitoring air pollution. ASSESSMENT For students In small groups, students will present their work to the class, if needs be presenting slides, to show the following - their skills in hypothesising results; - their understanding of the correlation between air quality and the health of the living beings through the health of the lichens; - their knowledge of different methods of measuring air pollutants; - their skills in the use of Palm hand-held computers and GPS; - their skills in the use of GIS. The quality of the presentation can be a good indication of the students ability to work in a group. To check individual preparation, the teacher may - ask for the interpretation of the LBI maps obtained; - ask for the experiment to be repeated in the school or a student s garden; - ask questions about lichen and tree identification and morphology; - aerify the ability to use GIS software with the creation of a map, or of a new attribute table. - submit a final test.

9 For student teachers and teachers In this module, what do you think of - the interest levels among students? - the importance for syllabus? - the integration with other subjects? - the adaptability to your own teaching methods? Have you any comments or suggestions for support teachers? What changes would you make? Would you change the sequence of activities? If yes, how? Did you find it easy to teach this module in your school? If yes, what? Did you find the suggested activities helped your students to learn about important concepts in science? If yes, which? If so, how? Did you find your students had particular difficulties with some of the suggested activities? If yes, which? How will you do it next time round?

10 BIBLIOGRAPHY References in the module text Capello, B. (2007). Documenting your emergent curriculum. Childcare Australasia, 3, Fleer, M., Edwards, S., Hammer, M., Kennedy, A., Ridgway, A., Robbins, J., et al. (2006). Early Childhood Learning Communities: Sociocultural Research Practice. Frenchs Forest: Pearson Education. Glass, B., Baker, K., Ellis, R., Bernstone, H., & Hagan, B. (2007). How Does an Inclusive Environment Enhance the Learning of All Children? New Zealand Childcare Conference. Paihia, New Zealand. Lee, W., Hatherly, A., & Ramsey, K. (2002). Using ICT to Document Children s Learning. Early Childhood Folio, 6, MacNaughton, G., & Williams, G. (2004). Teaching young children: Choices in theory and practice. Berkshire: Open University Press. Air pollution references (After modified): Edelson, Ed. (1992). Clean Air. New York: Chelsea House. Gay, K. (1991). Air Pollution. New York: F. Watts. Lucas, E., Challand, H.J., & Stubbs, H. (1991). Acid Rain. Chicago: Children's Press. Oliver, D.J. (1996). Killer Air Plagues. Bay Area: Oakland Tribune. Revkin, A. (1992). Global Warming: Understanding the Forecast. New York: Abbeville Press. Rock, M. (1992). The Automobile and the Environment. New York: Chelsea House. Sandak, Cass, R.A. (1990). Reference Guide to Clean Air. Hillside, NJ: Enslow. Tyson, P. (1992). Acid Rain. New York: Chelsea House. References about Lichens (After modified): Casselman, K.L. (1993). Craft of the Dyer - Color from Plants and Lichens. New York: Dover Publications. Esslinger, T.L., & Egan, R.S. (1995). A Sixth Checklist of the Lichen-forming, Lichenicolous, and Allied Fungi of the Continental United States and Canada. The Bryologist, 98(4), Goward, T., McCune, B., & Meidinger, D. (1994). The Lichens of British Columbia Illustrated Keys, part 1 - Foliose and Suamulose Species. British Columbia: Ministry of Forests, Research Program. Hale, Mason, E., How to know the lichens, Pictured Key Nature Series. Hale, M.E. (1983). The Biology of Lichens (3rd Ed). Baltimore: Edward Arnold Publ. Hawksworth, D.L., & Hill, D.J. (1984). The Lichen-Forming Fungi. New York: Chapman and Hall.

11 Galloway, D.J. (1985). Flora of New Zealand Lichens. Wellington: P.D. Hasselberg, Government Printer. McCune, B., & Goward, T. (1995). Macrolichens of the Northern Rocky Mountains. Arcata, California: Mad River Press. Thomson, J.W. (1984). American Arctic Lichens. Vol. 1: The Macrolichens. New York: Columbia University Press,. References about air pollution and lichens (After modified) Bates, J.W., & Farmer, A. (Eds.). (1992). Bryophytes and Lichens in a Changing Environment. Oxford: Oxford Science. Ferry, B.W., Baddeley, M.S., & Hawksworth, D.L. (Eds.). (1973). Air Pollution and Lichens. London: Athlone Press. Hawksworth, D.L., & Rose, F. (1976). Lichens as Pollution Monitors. London: Edward Arnold. Henderson, A. (1990). Literature on Air Pollution and Lichens. XXXII, Lichenologist, 22, Richardson, D.H.S. (1992). Pollution Monitoring with Lichens. Slough: Richmond Publishing. Italian references A.A.V.V. (2001). Manuale ANPA: I.B.L. Indice di Biodiversità Lichenica. Manuali e Linee Guida 2/2001 ANPA Dipartimento Stato dell Ambiente, Controlli e Sistemi Informativi. Malavasi, C. (2000). Progetto "Licheni in rete" - Labter Crea-Mn. Pieralli, P., & Traquandi, S. (1991). I Licheni. Guide all aria pura. Firenze: Editoriale Tosca (Da richiedere alla casa editrice). Valcuvia Passadore, M., & Malavasi, C. (2002). Relazioni simbiotiche: dai licheni all'agenda 21 locale. Regione Lombardia (Il manuale è disponibile presso il Labter Crea di Mantova)

12 APPENDIX 1 Sample grid Materials 2 pieces of wood (or plastic or bamboo) 52 cm long, 1-2 cm thick, nylon string (2-2.5 mm Ø), a drill. Method Make 6 holes at 10 cm distance on the two pieces of wood. Join the two pieces with the string at each hole, keeping 10 cm between the wood. Fix the string with a knot. You can also make a single grid to orient simultaneously all four points of the compass by simply constructing four grids in the same way and joining them with a sliding piece of string.

13 APPENDIX 2 Tree N Photo N Checked out area (city, street ) Coordinates Candelaria concolor Candelariella reflexa Lecanora allophana Lecanora carpinea Lecanora chlarotera Lecanora hagenii Lecidella elaeochroma Micarea sp. Caloplaca pyracea Rinodina pyrina Parmelia acetabulum Parmelia caperata Parmelia elegantula Parmelia exasperatula Parmelia subrudecta Parmelia sulcata Parmelia tiliacea Phaeophyscia orbicularis Physcia adscendes Physcia biziana Physcia clementei Physconea grisea Ramalina fastigiata Evernia prunastri Xanthoria parietina Orthotricum diaphanum Orthotricum striatum Tortula papillosa Hypnum cupressiforme var. fili. grid exposition grid high on the tree Specie Circumference LBI N LBI E LBI S LBI W If the lichen species are unknown, a practical method must be used to distinguish different species, based on their colour and/or morphology (crustose, foliose and fruticose morphology).

14 APPENDIX 3 Lichen Biodiversity Index LBI of the sample (one tree): sum of lichens present in single unit of grid per point of the compass; LBI of the station compass point (all trees): sum of all LBIs sampled at same compass point; LBI of station (all trees and all compass points): sum of LBI of compass points divided by the number of trees sampled Figure 1 Example of LBI calculation

15 LBI COLORS LBI NATURALITY/ALTERATION COLOR 7 0 Very high alteration Dark Red 6 1 LBI 15 High alteration Red 5 16 LBI 30 Medium alteration Orange 4 31 LBI 45 Low naturality/low alteration Yellow 3 46 LBI 60 Medium naturality Green 2 61 LBI 75 High naturality Dark green 1 LBI > 75 Very high naturality Blue Figure 2 - Colours assigned to different Lichen Biodiversity Index

16 APPENDIX 4 Lichen B (yellow) Lichen C (green) Lichen B (yellow) Lichen A (grey) Lichen A (grey) Lichen C (green) Figure 3 - Exemplum of lichens classification via their colours

EQA Environmental quality / Qualité de l Environnement / Qualità ambientale, 1 (2009) 1-6

EQA Environmental quality / Qualité de l Environnement / Qualità ambientale, 1 (2009) 1-6 AIR QUALITY MONITORING WITH THE LICHEN BIODIVERSITY INDEX (LBI) IN THE DISTRICT OF FAENZA (ITALY) MONITORING DE LA QUALITÉ DE L AIR AU MOYEN DE L'INDICE DE BIODIVERSITÉ LICHÉNIQUE (IBL) SUR LE TERRITOIRE