I believe your question in considering the use of "ethnic cleansing" in the comment in which you contrast that term with the existence of 60% forest in Bhutan has to do with a criticism that involves the complexities and paradoxes of eco-geo-ethno-politics there. Your question is about the use of "ethnic cleansing" within a comment that is critical of certain practices regarding people and trees in Bhutan, correct?
From what I read, the bombings in Bhutan have to do with clashes amongst groups, and the identities of those groupings have to do with ethnicity, power, and governance. "Ethnic cleansing" includes many tactics, some of which match the definition of genocide, but historically a combination of efforts are used simultaneously, so the distinction between just mass removal or just mass killings may not be practical in your definition.
(See the glossary terms in: "Race and Ethnicity" by Stephen Spencer - Routledge 2014)
As the world-wide debate continues about how any of those terms (ethnic cleansing, genocide, eugenics, etc) are defined and applied - particularly regarding who is doing the defining,
and who may or may not be apologizing, or who is arguing for reparations, or even who is actively denying those terms and just summing it all up as "warfare" - the contrast of so much human suffering in the name of environmental saving is a contradiction that seems to be sharpening globally. (The UN Charter on Genocide was ratified in the U.S. by Ronald Reagan sometime in the 1980's, but archaeologists have found evidence of Anasazi involvement in a genocidal action against another tribe as early as the early 9th century...http://news.discovery.com/history/genocide-native-americans-ethnic-cleansing.htm)
If this is the issue pertinent to your question, then I would agree that yes, it's nice that Bhutan has 60% forest, and that the "but" in the "but they also have committed ethnic cleansing" is a very big, complicated, and ever-sharpening "but". The caveat is that there really is no euphemism for genocide, no matter how you word it; making a speech-comment with the intention to sharpen a contradiction via a loaded term is what it is. Just be prepared for mixed responses, especially if speaking in mixed company.
(Ironically, there's an opposite story in what happened in New England and Washington's campaign against the Seneca, (Susan Brind Morrow's "Wolves & Honey" has a poignant and poetic treatment in her narrative); he had the trees killed in order to get rid of the people...)
The following is an abstract (relatively old) that I think expands your point in a very verbose and academic way, but there are a few phrases that seem to match the point of your comment.
"Forest cleansing: racial oppression in scientific nature conservation  L. Lohmann
Article looks at a specific case of racial oppression manifesting itself within development programs. At a more general level, the article looks at how ecological project can become politicised.
An example of this is South-East Asia, where valley-based states have regularly attempted to sedentarize or repress hill-dwelling ethnic minorities. Racist patterns and processes in the region have been sustained and strengthened through the activities of international environmentalists and developmentalists.
The potential for racial violence in the region is exemplified by a current conflict over water and forests in Chom Thong, a district in Chiang Mai province of Northern Thailand. Here, over the past decade, elite conservationists, state bureaucracies and politicians have helped each other exploit, rework and augment a legacy of highland-lowland ethnic tensions in the course of pressing for resettlement of mountain communities on "environmental" grounds and for greater elite and state control over mountain resources.The establishment by Thai elites, under the tutelage of US and other international conservationists, of parks and wildlife reserves has helped to entrench an upland vs lowland ethnic grid.
A simplified people-vs.-trees narrative of forest decline was superimposed on the realities of forest history, making it possible to reinterpret the character and persistence of highland forests as a result of the relative absence of human influence rather than of human stewardship or commercial inaccessibility.
In an irony often noted by minority observers, the disproportionate survival of good forest in minority-occupied areas was transformed into a reason for evicting minorities.Physical violence against mountain minorities, much of it unreported, has been an integral part of their increased stigmatization and scapegoating. The violence is directed, again following the standard racist dualism, at either removal or assimilation.
Certain conservation organisations involved in this issue have mobilised ethnic divisions in the service of "forest conseration" and centralisation through: Physical exclusion, Conceptual exclusion from the Thai nation! Division of minority groups from each other, dissemination of racial stereotypes.
Conclusion: Throughout their existence, campaigns to dispossess hill-dwelling minorities in Thailand have tapped the power of international racist science and development discourse. Understanding environmental racism means paying attention both to the uniqueness of particular cases and to wider parallels. Examples such as the one explored in this article provide rich materials for understanding evolving patterns of ethnic violence and their links both to local and regional inter-class politics and resource competition and to structures of racism embedded in international science and mainstream environmentalism"**
Here's the link - http://agris.fao.org/agris-search/search/img/FAO-logo.png
(Please forgive my lack of visually helpful formatting - my iPad doesn't seem to agree with this platform - in future I will compose on a computer!)