…USUFRUCT. (Sorry, I grew up too Catholic to pronounce it that way! ;) )
This is the Common Law principle on which is based the occasional English and successor Settler States (USA, Canada, Australia, I know for certain, maybe others) practice of deigning, that is to say condescending, to let Aboriginal Peoples in “their” countries retain (I say retain) certain rights with regard to their “former” territories and their tribesmembers. It’s the theoretical basis of Reservations, remnant fishing / trapping / hunting / subsistence rights, regard for Tribes’ Sovereignty (to attempt to put it into European terms), Native Treaties, Lands Held in Trust (including royalties [at 18th-century rates]…if only Uncle Sam can remember where he put them!), etc.
The alternative might well have had to be full military defeat, actually wiping out all our ancestors … genocide in its simplest, bloodiest sense — I’ll say it — ala Hitler. And I deduce that conundrum is where the idea came from, IOW, Settler convenience, politics, occasional conscience. The earliest case I know of — though I’m no professional historian — where English courts upheld native legal status is only The Case of Tanistry in the early 1600s. Here the Irish lost by winning (300 years before they won by losing!): the court employed traditional Irish Brehon Law to cheat a rightful traditional clan chief of his chiefly lands in favor of English-Law inheritance previously unknown among traditional Irish … four-and-a-half centuries after first invading. My current point being, the English certainly have become experts at riding roughshod over Irish culture (which is why 1998′s Good Friday Northern Ireland Peace Agreement was such a monumental reversal for them). I guess they didn’t always enjoy how hard it was, and so decided to take a (slightly) less harsh approach in Quebec and North America beyond (to the frustration of the greedy and anti-Catholic eastern seaboard “Founding Fathers”), and Down Under. (In New Zealand, the Treaty of Waitangi is even considered technically part of the national constitution!)
Anyway, as Merriam Webster reminds us, a usufruct is Europeanly-considered technically only temporary — in our case, until the “death” of each Native Nation, envisaged by (unconstitutional) Blood Quantum laws, mandatory dispersion and exogamy, ethnic/racial cleansing, culturecide, divide-and-conquer, even leaving Tribes with the worst-quality land around on which to survive, as well as what I compare to illegal and unjust “constructive eviction” in attempting to claim a Native Community “abandoned” a temporarily-disused right or plot of land.* Conveniently, the U.S. has never recognized Mixed-Bloods as such, as Canada has in its Métis since just 1982, otherwise Native Nations might never die!
(*–The Settlers of Maryland Colony did this to my Nanticoke people. Once they interpreted an Abandonment Clause in a colonial treaty to mean temporarily going up the Susquehanna River for their traditional annual hunt relinquished one of their Reservations: But when they arrived to find one elderly man guarding the otherwise-empty village, they burned him alive in his home.)