> For the complete documentation index, see [llms.txt](https://swatplus.gitbook.io/io-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://swatplus.gitbook.io/io-docs/introduction-1/databases/plants.plt/bm_tree_acc.md).

# bm\_tree\_acc

Fraction of biomass accumulated each year that is converted to residue during dormancy

This variable pertains to trees only. It is not used for other types of plants. It governs the amount of biomass that falls off the tree and is converted to residue when the plant goes dormant in the winter.