"open easily" is correct and usable in written English.
You can use it to describe an object that is easy to open. For example, "This jar of peanut butter opens easily."
ROUND 2: COMPATIBILITY The previous versions of Pages had a serious problem: Documents created on Pages for the Mac didn't open easily on Pages for the iPad.
Instead "customers have been wanting smaller, simpler bags that open easily," said Rose Redondo, a sales clerk at Flight 001, a travel store on Greenwich Avenue.
Meanwhile, even a solid door with a deadbolt can be pushed open easily if the strike plate isn't secured to the door frame with screws at least 2 1/2 inches long, said Mr. Zakhary, who is the chief of police in Woodway, Tex.
"My house, being always open, easily approached and ever ready to welcome all men (since I have never let myself be persuaded to turn it into a tool for a war in which I play my part most willingly when it is farthest from my neighborhood), has earned quite a lot of popular affection," Montaigne wrote, about a year later, in the essay he called "On Vanity".
(Plus, these jars don't open easily, I must note).
Certainly the limited destructive sample for large tree sizes would explain the high biomass density discrepancies, but it is conceivable that destructively harvested trees were also preferentially extracted from open, easily accessible areas with lower canopy covers.
