Is it unethical to cut down trees to measure biomass?

In the earlier times (like approximately 100 years ago) scientists used to kill animals and dry them in order to measure their biomass, however as the time passed humans became more sensitive/protective of animals and animal rights. So nowadays it isn't acceptable to kill animals to measure their biomass, but still scientists are cutting down trees to measure their biomass. Trees are also living organisms, just because they are fixed/stationary doesn't give the right for scientists to kill them, so I believe this is an unethical thing to do. They should find some other way to measure their biomass, there should be a different solution, plus cutting down trees also disturbs the natural order on earth, trees (producers) are vital for consumers since consumers depend on them. Things on earth are rapidly changing and globalization is one of the thing which affect this change the most, the understanding of ethics are also changing with the changing society and their changing ideologies. Hopefully soon enough people would realize that cutting down trees isn't any different than killing animals, people should be aware of the deficiencies this act might cause and people should be informed about the importance of trees in our lives.