Is it illegal to live on the second floor without cutting down trees? How to report it?

Not illegal. It is not illegal to live on the second floor without cutting down trees, and report the property to the local real estate administrative department. If the trees in the residential area are cut down by the property, you can report to the administrative department of urban greening, unless the property has gone through the relevant examination and approval procedures. Property management refers to the maintenance, conservation and management of houses, supporting facilities and related sites by property management enterprises in accordance with the property service contract, so as to maintain the environmental sanitation and order in the relevant areas.