About halfway through Wetlands Preserved, an appropriately mellow chronicle of a Tribeca nightclub’s lifespan, music writer Richard Gehr declares that there is no good nostalgia. While I don’t agree, director Dean Budnick’s lope down memory lane occasionally errs on the side of bad nostalgia. That is to say, it’s a boutique documentary whose ideal audience is so tightly knit that they probably already know all about, say, the time the Spin Doctors broke the Blues Traveler’s drinking record. But the Wetlands Preserve, which nursed those acts in their early days, also offers a classic New York story. Founded by a Deadhead dreamer named Larry Bloch in 1989, Wetlands was part music scene, part “social-justice activist center,” with hundreds of thousands of dollars in proceeds going to environmental causes. From the VW bus parked inside to the recycled matchbooks, Bloch mingled his hippie ethos with a love of improvised music and community. That love was challenged when the neighborhood changed into one that didn’t dig endless solos and pee-stained streets. Cue Giuliani’s martial law enforcement, the sale of the club to a sympathetic post-grad whippersnapper, and the ruthless condo revolution. Wetlands closed in 2001, and while late lamenteds like CBGB and the Cedar Tavern may have a more storied lineage, the fate of Bloch’s club is a wistful reminder of how rare a come-one, come-all scene is in an increasingly exclusive Manhattan.