At more than five hundred acres, little-known Knowland Park is Oakland's single largest parcel of open space. It's also of immense ecological value, environmentalists say. The oak and riparian woodlands and perennial grasslands on Knowland's rolling hills host an array of native plants and animals, some of which are rare, endangered, or otherwise protected. But 56 acres of the picturesque parkland and its native species are now threatened by a planned expansion of the Oakland Zoo, which, ironically, wants to build a new exhibit celebrating California species that have lost their habitats. Environmentalists also contend that the zoo, an organization ostensibly dedicated to conservation, is trying to skirt California environmental laws that are designed to protect threatened and endangered wildlife.

For example, Laura Baker, conservation chair of the California Native Plant Society, argues that the zoo's plan to protect a rare native wildflower colony within a proposed wolf enclosure is woefully insufficient because it involves little more than watching to ensure the wolves don't dig up the plants. "We find it absurd to trade off any currently threatened species to showcase other endangered or extirpated species," Baker said. "It makes a mockery of the whole concept of the 'California!' exhibit."

Abundant flora at Knowland Park include purple needlegrass (the California state grass), mature coast live oaks, and some of the last remaining undisturbed California chaparral in the East Bay. Hawks, owls, foxes, deer, and red-legged frogs also make their home there, and a federally protected Alameda whipsnake was identified on three occasions in 2010. The zoo, which occupies 44 acres in lower Knowland Park, wants to expand to more than twice its current size to make room for California creatures including Tule elk, mountain lions, condors, beavers, and grizzly bears in a hillside setting.

Ruth Malone, co-chair of Friends of Knowland Park, a community group established four years ago when the zoo proposed an amendment to expansion plans originally approved in 1998, doesn't believe the zoo has adequately accounted for the protection of existing native species. "This is going to be permanent," she said. "This is something that is going to take away this public resource forever. You're not going to get this biological hotspot back."

When Oakland Zoo officials first received City Council approval in 1998 for the proposed expansion into upper Knowland Park, they probably thought they finally had neighborhood activists out of their hair. After all, a year and a half of deliberations had concluded with expansion opponents signing off on the plan. Everything was fine until four years ago, when the zoo announced it was ready to start the work — only under an updated plan. Now, a new coalition is fighting the zoo's revised proposal on environmental grounds, even though the zoo insists its updated plan is actually greener than the last.

Oakland Zoo Executive Director Joel Parrott said he doesn't understand why the conflict has flared up again. Most of the amendments to the original expansion plan — which was approved by some of the same neighborhood activists back in 1998 — were designed specifically to decrease the zoo's impact on the land, he said. These changes include replacing a diesel shuttle-bus system with an electric aerial gondola; swapping a three-acre river exhibit for a three-quarter-acre veterinary hospital; adjusting the perimeter fence to avoid chaparral and Arroyo Viejo Creek while retaining public access to the park's popular knolls; and moving an interpretive center away from homes and further down the ridgeline.

But Malone and other critics don't necessarily take every change to be an improvement. They also believe that according to the California Environmental Quality Act, the sheer scope of the amendments — as well as significant environmental circumstances that have changed since 1998, including the identification of the threatened Alameda whipsnake and the discovery of highly transmittable Sudden Oak Death in the park in 2009 — demand a more rigorous environmental review than the zoo has performed to date.

In February, the zoo officially introduced its revised master plan in the form of a 1,300-page document known as a mitigated negative declaration, which argues that after measures the zoo will take, the project will not have a net negative effect on the environment. Friends of Knowland Park, however, along with environmentalists representing the Sierra Club, Golden Gate Audubon Society, California Native Grasslands Association, and California Native Plants Society, argue that the project calls for a more intensive environmental impact report.

Friends of Knowland Park, which claims more than 1,000 members from throughout the Bay Area, is prepared to file a lawsuit if the plan proceeds without such a document. In fact, it's already taking collections for a legal fund. "According to our lawyers, an environmental impact report is required by law," Malone said. "We're trying to get the city to see that this is the right thing to do, and this is the legal thing to do."

They're not alone in the sentiment. UC Berkeley Forest Pathologist Matteo Garboletto found that the zoo's master plan completely ignores the existence of Sudden Oak Death in Knowland Park, even though construction could further spread the disease throughout the area. Oakland conservationist Ralph Kanz believes that the discovery of the Alameda whipsnake alone warrants far stricter mitigation measures than are currently proposed.

Parrott, however, maintains that the zoo's existing environmental review is not only thorough but legally defensible. "Anybody who has a sense of impact on the environment would know that this is a far smaller impact on the environment, and it's far more responsible," he said. "They can threaten to sue, but they better check the law first, because the City Attorney's Office definitely checked the law on what would be required."

But neighborhood activists' problems with the zoo don't end there. Friends of Knowland Park representatives say they'd be more apt to accept the zoo's mitigations and Habitat Enhancement Plan, as described in the 1,300-page proposal, if they trusted its ability to serve as a steward of the park. Citing the zoo's alleged dumping of construction debris and animal manure within the park, intentional bulldozing of a vernal pool known to serve as a frog breeding ground, and improper removal of invasive French broom, among other alleged infractions, the group's sixty-page response to the zoo's amended master plan amounts to what's essentially a vote of no confidence.

Oakland's City Planning Commission is currently reviewing the objections raised by Friends of Knowland Park, along with hundreds of other public comments on the zoo's new expansion plan, and will release its findings at a public meeting on Wednesday, April 20, at 6 p.m. in City Hall. The project could go before the full city council as soon as early May, and, if approved, break ground shortly thereafter — unless it's stopped by a lawsuit. If not, construction would be performed in phases, with a projected final completion date of 2017. If the council does not approve the amendment, zoo officials say they'd have to revert to the more impactful 1998 plan.

Malone wants a third option — further revision of the project based on the findings of a full environmental impact report. "I would prefer a plan that protected the character of the park as a park while allowing an expansion," she said. "There is room to do that and with creativity. I believe a win-win is possible."