The Montgomery County Council passed a pair of measures Tuesday intended to protect and expand tree cover along public roads and on private property where new construction has disturbed the environment.

Approval of the bills culminates several years of bargaining between the county, builders and environmentalists. One measure requires landowners who cut down a tree along a public right of way to obtain a county permit and replace the tree at or near the site. It also requires the landowner to pay into a tree replacement fund so that the county can plant two additional trees.

State law already regulates protection of roadside trees, but supporters say the county bill, sponsored by council members Roger Berliner (D-Potomac-Bethesda) and Marc Elrich (D-At Large), is more stringent.

The other measure, proposed by County Executive Isiah Leggett (D), is aimed at preventing loss of tree canopy from new home construction, especially in older downcounty neighborhoods. It requires builders to plant three trees for every one lost to construction or to pay a fee to the county. Supporters of the bill say infill development — building in the spaces within a built-up areas — has seriously eroded the tree canopy, especially in Bethesda and other older communities.

Council members said they were gratified with the result of lengthy negotiations. Valerie Ervin (D-Silver Spring) invoked the Lorax, the Dr. Seuss character who “speaks for the trees.”

“It seems to me that today we’re speaking for the trees,” Ervin said.

In other business, the council heard from county officials and Washington Metropolitan Area Transit Authority representatives about the ongoing disagreement over planned repairs to the Silver Spring Transit Center. Rodrigo Bitar, WMATA assistant general manager, said the county was rushing into fixes to the troubled $120 million bus-and-train hub without understanding the root causes of the center’s design and construction problems.

Bitar noted that new cracks have developed in the two 10-by-40-foot roadway slabs the county is preparing to fix. Bitar said WMATA, which is supposed to operate the facility when it is finished, does not believe it is unsafe. But the new fissures — which have emerged before any bus traffic actually places loads on the structure — underscore uncertainty about its long-term durability.

“This is of great concern to WMATA,” he said.

Bitar said the transit agency wants the county to use a procedure called “slot stress testing” for a broader assessment of the strength of the structure. The tests would cost $800,000 and take 12 to 18 weeks, throwing off a timetable that calls for repairs to be finished by the end of the year.

David Dise, Montgomery’s director of general services, said some of the cracking is “normal” and a result of the structure’s natural settling. It may also reflect design problems that will be remedied when the slabs are repaired.

Dise said he believes no additional tests are necessary.

“This facility has been thoroughly examined,” he said. “Excruciatingly thoroughly examined.”