If you live around Champaign County, the Forest Preserve District is recycling trees. Those could be used for fish habitats or they could get chipped and used as mulch. They have three places in the county where you can drop them off. To find out more about that, you can click on this link.
If you live within the city limits of Champaign or Urbana, city workers can come pick up your tree.
To find out about Champaign's pick-up, click on this link.
To find out more about Urbana's pick-up, click on this link.