US Forest Service e u phephetsa hore u tsoe ka ntle 'me u nke linepe tsa moru oa hau oa litoropong kapa oa sechaba. U ka hapa $200 ka lisebelisoa tsa kantle ho tsoa ho National Forest Foundation.
Ho bala melao e felletseng ea tlholisano kapa ho fana ka senepe, etela urbanforest.challenge.gov.