Air Quality Monitoring with Epiphytic Lichens

Transcription

1 CEW Field Guide: SEPTEMBER 2002 Written by: Jeffrey Borisko Illustrations by: Miyako Kurihashi Citizens Environment Watch 2 Sussex Avenue. Toronto. Ontario. M5S 1J5 Telephone: Fax: env.watch@utoronto.ca

2 Table of Contents 1. Preface Introduction Legal and Safety Considerations Equipment When To Sample Where To Sample Selecting Trees Defining the Sampling Band Determining Lichen Presence/Absence Estimating Lichen Abundance Sampling Site Profile Final Checklist...11 Acknowledgements This field guide would not have been possible without the contributions of many individuals. CEW is grateful to the following people for their contributions and support: Dr. Irwin Brodo (Canadian Museum of Nature) Lionel Normand (Toronto Region Conservation Authority) Brian Craig (Ecological Monitoring and Assessment Network, Environment Canada) Dr. Tom Hutchinson (Trent University) James Richardson (Consultant) Dr. George Sorger (McMaster University) Irene Hinkle (Western Washington University) Dr. David Richardson (St. Mary s University) Citizens Environment Watch 2

3 Preface Citizens' Environment Watch (CEW) is a non-profit organization dedicated to environmental education, monitoring and identifying environmental quality concerns in communities. CEW brings accessible, relevant and exciting hands-on learning experiences to citizens and community groups. By providing surface water and air quality monitoring resources and training, CEW helps volunteers to take the first step toward achieving positive environmental change. A Step by Step Field Guide is a step by step biomonitoring field guide for community organizations and high school students. To achieve credible, defensible results, it is recommended that all users of this guide first attend a CEW field training session. Field Guide Format Epiphytic Lichen Monitoring Field Guide Each step title appears on left side of page. 1. Procedure appears as a numbered list to the right of each step title. 2. Be sure to follow each step in order to ensure accurate results. This symbol indicates the need to record information on your datasheets. Boxes contain important information that will help you complete your epiphytic lichen sampling. Diagrams appear throughout field guide to illustrate important sampling steps. When possible they appear alongside the step they are referring to. Citizens Environment Watch 1 Citizens Environment Watch 3

4 Introduction Epiphytic lichens, found on tree bark, are a symbiotic association of fungi and algae or cyanobacteria (blue-green algae). Because lichens exhibit varying tolerances to changes in air quality, they can be used as indicators of air pollution. This procedure has been developed to enable volunteers to sample terrestrial habitats for lichens growing on trees in a communitybased environmental monitoring program. This field guide includes necessary information for surveying and identifying indicator lichen species in southern Ontario. Additional on-line materials for carrying out this procedure are available through the CEW website, including data sheets, detailed identification guides and information on data analysis and interpretation.. Legal & Safety Considerations Insurance. Be sure that you have properly addressed the following questions: Are you and your group insured? What are you insured for? Are you required to take any specific safety or administrative actions to ensure proper coverage? Trespassing. Always get permission or notify those individuals who own or are responsible for the site that you are sampling. Sampling sites. If you suspect that a selected site may pose a risk to your health or safety (e.g. poison ivy, automobile traffic), seek qualified advice before sampling. Equipment. Take care when using sampling equipment that may cause physical injury. Bring a partner. Always sample with a partner who can help in case of emergency First Aid. Bring a first aid kit in case of emergencies. Equipment Lichen sampling: Lichen key/guide 10x magnifier (hand-lens) Tape measure (at least 2 m) Compass Chalk Fluorescent flagging tape Hand ruler CEW data sheets Waterproof pen or soft pencil Flashlight Other equipment and materials: Site map (topographic and/or road) Tree identification guide Camera Tape measure (at least 25 m) GPS Unit (if available) Clip board For safety: First aid kit Cell phone (if available, in case emergency help is needed) When to Sample Lichens can be sampled during any season, but sampling during or immediately after a rainfall should be avoided. Rainfall causes many lichen species to change colour. This can result in the misidentification of species. Citizens Environment Watch 4

5 Where to Sample The choice of your sampling site is important if you wish to compare your results with other participants following the same procedure. Sites that are similar to each other are more appropriate for comparison. Also try to find sites that are representative of the larger area you wish to assess. The most important consideration for your sampling site is your health and safety. Choose sampling sites that do not pose any known or potential risks. The characteristics within each sampling site should also be as uniform as possible. For example, patches of visibly different tree density and topography may create different microclimates within a site. Since lichen growth and reproduction are affected by sunlight and wind exposure, areas of high tree density, which experience reduced sunlight and wind, may support different lichen species, abundance and diversity than patches with lower tree density. These recommendations may not always be practical, therefore, details on sampling site characteristics need to be documented (see later section). Sampling sites for air quality surveys using epiphytic lichens should support at least 10 trees of the following species: red maple (Acer rubrum), silver maple (Acer saccharinum) or sugar maple (Acer saccharum). These trees must have a circumference at chest height of at least 45 cm. An initial site assessment should be conducted prior to any lichen survey. This activity can be facilitated by CEW staff. Selecting Trees For this protocol and to make more appropriate comparisons between sampling sites, the following tree characteristics are required: Tree species must be either red, silver or sugar maple. Tree circumference at chest height is at least 45 cm (0.45 m). 1. Tie a piece of flagging tape around the lowest branch or trunk of the selected tree. If your site has more than ten suitable trees (red, silver or sugar maples with a CCH of at least 45 cm), your sampled trees should ideally be randomly selected within your sampling site to reduce possible bias. 2. Write the initials of the group members and a unique letter for the tree on the flagging tape. Record on your data sheet the tree species to be surveyed. (All markings on your data sheet should be in soft pencil or waterproof pen.) 3. Measure 120 cm upwards from the base of the tree using your tape measure. Mark this point on the tree trunk with chalk. Citizens Environment Watch 5

6 4. Measure the tree circumference at this level using your tape measure (see Figure 1). This measurement is called the Circumference at Chest Height (CCH). The point you marked will become the lower limit of your sampling band. Record the CCH in centimeters on your data sheet. 5. Measure the distance to the nearest tree of equal or greater CCH using your tape measure. This is called the Distance to Nearest Tree (DNT). Record the DNT in meters on your data sheet. Complete the remaining boxes in section VII on your data sheet. Figure 1: Circumference at Chest Height Citizens Environment Watch 6

7 Defining the Sampling Band 1. Find the mark you made on the tree trunk 120 cm above the ground. 2. Make a series of marks around the tree trunk at the same height. This is your lower limit. 3. Measure 30 cm upwards from the lower limit using your tape measure. (The total height above the ground should be 150 cm.) 4. Mark the tree with chalk (e.g. small x) 30 cm above the lower limit. This is your upper limit. 5. The area between the upper and lower limits is the sampling band. (refer to Figure 2). Figure 2: Sampling Band Determining Lichen Presence/ Absence It is recommended that you complete the following sections in groups of 2 to 3 people. 1. Slowly walk around the tree and look for lichens within the sampling band. 2. Observe and note each visibly different lichen. 3. Look closely at each visibly different lichen with your 10x magnifier. 4. Use your field guide to determine which of the indicator lichen species are present. Be sure to inspect the sampling band carefully. Some lichens can be overlooked if care is not taken. Be sure not to mistakenly count moss or algae growth on the tree as lichen. Do not include dead lichens. These lichens will have no colouration (i.e. appear mottled white or pink) due to the absence of functional algae or cyanobacteria. Citizens Environment Watch 7

8 Record on your data sheet a ZERO for each indicator lichen species not present and a ONE for each indicator lichen species present. 5. Note the presence of species on your tree that you suspect do not match any of the indicator lichens in your guide (i.e. other ). Describe on your data sheet any other lichen species present. The identification of each indicator species should be verified by at least one other group member. If you suspect that a lichen is not found in the identification guide, seek assistance from a qualified individual. Estimating Lichen Abundance There are four levels of percent abundance that will be recorded. These are 0%, 1-25%, 26-50% and greater than 50%. Figure 3 illustrates three abundance levels for a single lichen species. Figure 4 illustrates two levels of lichen abundance for three species. 1. Walk around the tree and observe the total surface cover (ie. percent abundance) for all indicator lichen species TAKEN TOGETHER within the sampling band. 2. From your observations, assign the most appropriate total percent abundance level for all indicator species TAKEN TOGETHER. Remember, this is an estimate and should not require a great deal of deliberation. For trees with deeply grooved bark, do not include inner surfaces perpendicular to the tree, as this makes the determination of lichen abundance more difficult. The estimation of lichen abundance should be verified by at least one other group member. Record on your data sheet the appropriate lichen abundance category for all indicator species TAKEN TOGETHER. 3. Determine the most appropriate percent abundance level for EACH indicator lichen species, separately. Record on your data sheet the appropriate lichen abundance category for EACH indicator and other lichen species. 4. For each indicator lichen species, determine the side of the tree with the greatest abundance. 5. Using your compass, determine the facing direction of greatest abundance for each indicator and other lichen species. Record on your data sheet the facing direction of greatest abundance for each indicator land other lichen species. 6. Repeat the sampling procedure for the nine nearest maple trees. Be sure not to sample the same tree twice. Citizens Environment Watch 8

9 Figures 3 and 4: Estimating Lichen Abundance Sampling Site Profile This section should be completed once your group has sampled at least 10 maple trees for lichens. Only one sampling site profile needs to be completed. 1. Site Sketch Sketch on your data sheet in overhead view the boundaries of your sampling site. Include in your sketch any permanent features within the boundaries of your sampling site (e.g. walkways, fences, benches). Find all flagged and sampled trees in your sampling site with group members initials and assign a unique number or letter. Citizens Environment Watch 9

10 Record in section VI of your data sheet the unique number/letter for each sampled tree and plot the location of each tree with the unique number/letter within the boundaries of your overhead sketch. Sketch on your data sheet any permanent features around the boundaries of your sampling location (e.g. roads, buildings, hills, rivers). Use Figures 5 and 6 as a guide for your sampling site profile. Figures 5 and 6: Sketching Your Site Citizens Environment Watch 10

11 If you have a camera, take photographs that are representative of your sampling site. Additional photographs of sampled trees are also useful. Record any unusual observations, site conditions, sampling difficulties etc. on your data sheet. 2. Site Characteristics Determine the direction of magnetic north with respect to your sampling site using your site sketch and compass. Record the direction of north on your data sheet. Complete the remaining boxes in section II of your data sheet. If you have access to a GPS unit, record the UTM for your site in section I of your data sheet. If possible, record the longitude and latitude for your sampling site in section I of your data sheet. Final Checklist 1. Check your data sheet to ensure that it is complete and legible. 2. Give your completed data sheet to your group leader. 3. With your group leader s instruction, remove markers, flagging tape etc. from your sampling site. Leave the site in the same state as you found it. Citizens Environment Watch 11