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# Background
Lichen are not plants, but rather a symbiotic relationship between fungi and algae and/or cyanobacteria. Macrolichen (leafy or bushy lichen) that grow on trees obtain all their nutrients from the surrounding air, moisture, and rain, which means that they also absorb many of the chemicals and pollutants present in the air and can serve as mini living air quality monitors. You can learn more about lichen and their main functional groups in this [research note](https://publiclab.org/notes/fongvania/07-21-2021/learning-to-spot-lichens-and-mosses)

This page will hopefully be helpful to folks at various stages in the air quality study design process. Anyone just starting to design an air quality study or reassessing an ongoing study can use this wiki to assess whether bioindicators can and should be integrated into the study. 


## Use Cases and Limitations
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# Methods

##Categories of Methods

||Elemental Analysis|Community Analysis|Physiological Assessment|Transplant Study|
|------|------|------|------|------|
|**Description**  |Collect lichen samples for laboratory analysis to determine identifies and concentrations of elements of interest|Collect and compare information on richness, abundance, and presence/absence of indicator species over geographic space or time.| Analyze changes in lichen anatomy and photosynthetic ability of naturally occurring lichen or transplanted specimens in response to exposure to pollutants. Examples of parameters to measure include chlorophyll concentrations, chlorophyll fluorescence, cell membrane integrity, CO2 exchange capacity.|Transplanting healthy lichen to a test area and measuring physiological response and/or elemental accumulation.|
|**Expertise Required**||||
|**Equipment**||||
|**Cost**||||
|**Considerations**||||

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##Specific Methods

**Community Analysis**

**Physiological Assessment**

**Elemental Analysis**

##Other Guidance for Study Design

**Determining Lichen Species of Interest**

**Spatial Sampling**

**Converting Observations to Air Quality Indicators**

**Consulting Experts**

#Resources
**Hands-On Learning**