# MEGAN v3.2: How Should Ecotype Data Be Defined for Regional Applications?
**URL:** https://forum.cmascenter.org/t/megan-v3-2-how-should-ecotype-data-be-defined-for-regional-applications/6267
**Category:** MEGAN
**Tags:** cmaq, emissions, megan
**Created:** [August 12, 2026, 2:57pm UTC](https://forum.cmascenter.org/t/megan-v3-2-how-should-ecotype-data-be-defined-for-regional-applications/6267 "2026-08-12T14:57:34Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@bb404bb](https://forum.cmascenter.org/u/bb404bb)
#### Post date: [August 12, 2026, 2:57pm UTC](https://forum.cmascenter.org/t/megan-v3-2-how-should-ecotype-data-be-defined-for-regional-applications/6267/1 "2026-08-12T14:57:34Z")
Hello everyone,
I am currently trying to use **MEGAN v3.2**. I have mostly understood the general workflow and am now able to generate BVOC emissions for use in the CMAQ model.
However, I am still unclear about the **Ecotype input data**.
My study domain mainly covers **East Asia, including Taiwan**. In particular, when I examined the Ecotype information over Taiwan, I found that the tree species ID assigned in the Ecotype dataset is **5277**.
I searched through the input files to identify what species ID 5277 represents, and found that it is listed as **TEOWBtr5277**. However, I am not sure what this vegetation/species code actually represents.
My questions are:
1. **What does the vegetation code `TEOWBtr5277` represent?** Is there a documentation or lookup table that explains these codes in more detail?
2. For regional applications such as East Asia or Taiwan, **is it necessary to modify or customize the Ecotype/species composition** , or is it recommended to simply use the default Ecotype dataset provided by the MEGAN developers?
3. If the default Ecotype data are used, **how might an inappropriate or non-representative species composition affect the simulated BVOC emissions and subsequent air quality simulations?**
I would especially appreciate hearing from researchers who are currently using **MEGAN v3.2**. How do you usually handle the Ecotype input when applying MEGAN to a specific region? Do you use the default Ecotype data directly, or do you customize the Ecotype/species composition based on regional vegetation information?
Any advice, references, or examples of how others have handled this issue would be greatly appreciated.
Thank you very much for your help!
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### Author:  [@willison.jeff](https://forum.cmascenter.org/u/willison.jeff)
#### Post date: [August 12, 2026, 3:15pm UTC](https://forum.cmascenter.org/t/megan-v3-2-how-should-ecotype-data-be-defined-for-regional-applications/6267/2 "2026-08-12T15:15:15Z")
The ecotype inputs are created upstream from the EPA-implemented code. The development of these files is somewhat opaque to me. I recommend contacting Alex Guenther about this. Here is the developer’s website: [UCI BAI - MEGAN](https://bai.ess.uci.edu/megan)