The Joshua tree does not require protection under the Endangered Species Act, the Fish and Wildlife Service said in a decision announced Wednesday.

Conservationists had petitioned the service in 2015, seeking to have the iconic desert plant and namesake of Joshua Tree National Park in Southern California listed as a threatened species. On Tuesday, the petitioners, a group called Wild Earth Guardians, filed a lawsuit complaining that the service was long overdue to respond to their petition.

Fish and Wildlife, part of the Department of the Interior, said Wednesday that it had determined that the Joshua tree's habitat is primarily on federally managed land, and has seen "no major contraction in populations" in the last 40 years. Joshua trees are found not only in California but also in Nevada and Arizona.

Federal wildlife officials on Wednesday also declined to protect eight other species across the U.S., citing commercial and scientific data. The determinations come two days after the Trump administration unveiled changes to how the Endangered Species Act will be implemented, including ending a ban on considering economic impacts and decreeing that climate change impacts should not be considered.

Secretary of the Interior David Bernhardt has called the changes “improvements to regulations" and Commerce Secretary Wilbur Ross has praised the changes, saying they would ease the regulatory burden on the American public.

Agency: Joshua trees have 'enough resiliency'

The decision from the Fish and Wildlife Service's Carlsbad office reviewed the primary stressors to Joshua trees, among them wildfire, invasive plants, effects of climate change, and habitat loss. However, because the two species of Joshua tree, Yucca brevifolia and Yucca jaegeriana, still occupy their historical ranges of roughly 12 million acres, there is “enough resiliency in the population despite threats acting on them,” the service said. The species native to Joshua Tree National Park, Yucca brevifolia, has a historic range of 6.4 million acres, the service said.

Taylor Jones, the biologist and advocate who authored the petition, expressed frustration with Wednesday's decision.

“It appears that this administration is ignoring the science because they don’t believe in climate change,” Jones said. “This is blatant disregard of the climate crisis.”

Jones' petition cited climate models indicating the Joshua tree could lose roughly 90% of its habitat in the next 80 years, should the most severe climate conditions bear out. The gradual warming and drying of Southern California, which could see average maximum temperatures in July rise by as many as five or six degrees, could reduce the Joshua tree population in California to one small refuge in the center of Joshua Tree National Park.

It is unclear whether the agency agrees with the projections cited by Jones, though the findings state that “future stochastic and catastrophic events would not lead to population- or species-level declines in the foreseeable future.” A more detailed examination of the climate change impacts is still to be released, and will include the agency's own 80-year projections.

“This administration has a history of climate-change denial," Jones said. "President Trump called climate change a hoax, and Bernhardt discounted climate change when opening up public lands to oil and gas development. Denial of protections to Joshua trees fits that pattern.”

Changes to the Endangered Species Act

This week's changes to the Endangered Species Act for the first time allow authorities to compile and review economic impacts of protecting a particular species during the review process; end blanket protections for animals newly deemed threatened; and reduce the scope of assessments during the listing review process. Instead of blanket protections for threatened species, officials said they will require “species-specific regulations for protective status.”*

Legal challenges are expected by California and other states, as well as environmental groups.

“Even as we suffer an extinction crisis and a climate emergency, the Trump administration continues to serve only narrow corporate interests,” said Tierra Curry, a senior scientist at the Center for Biological Diversity. “By shooting down protections for these imperiled plants and animals, Trump officials are displaying contempt for America’s natural heritage."

More:Joshua trees, monarch butterflies among species that may be impacted by Endangered Species Act change

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Wednesday's decision on the Joshua tree was not made public as a result of Wild Earth Guardian's court filing on Tuesday, according to a Department of Fish and Wildlife spokesperson, Jane Hendron. Wild Earth Guardians said in a statement Wednesday it plans to file another lawsuit appealing Tuesday's decision.

Sen. Dianne Feinstein (D-Calif.) responded to Tuesday's announcement by saying: "The iconic Joshua tree defines the California desert, but it could be lost forever if the administration has its way." Feinstein also criticized the Trump administration's rule changes for the Endangered Species Act.

Bee, mussels, blackbird also rejected

Besides the Joshua tree, the Fish and Wildlife Service said Wednesday it would decline to extend protections to another tree, freshwater mussels, reptiles and insects across the United States.

Petitioners were seeking protections for species including:

the Arapahoe snowfly

the brook floater and smooth pimpleback (two types mussels),

golden orb spider

the seaside alder, a tree

the tricolored blackbird

the yellow-banded bumble bee.

The agency asked the public "to submit to us at any time” any new, relevant information on the status of the species or their habitats.

Commercial as well as scientific information was used in the decisions not to protect the species, the federal agency said. Critics say economic impacts should not be allowed to outweigh biological and other research. Home developers, farmers and others have long argued that economics should be weighed as well.

The brook floater, a North American mussel, has historically been found from Georgia to Nova Scotia and New Brunswick, clustered in sand pockets behind boulders and stream banks. The medium-sized mussel has been wiped out of approximately half of its U.S. locations, making the Canadian population “an important global stronghold for the species,” according to Fisheries and Oceans Canada.U.S. wildlife officials said there are also resilient populations in North Carolina and Maine.

More:Imperiled by climate change, Joshua trees could be declared a threatened species

More:How Minerva Hamilton Hoyt saved Joshua Tree park for future generations

California’s tricolored blackbirds have declined by nearly 90% since the 1930s because of the destruction of wetlands and grasslands, pesticide use that wipes out their insect prey base and loss of nest sites during agricultural operations, environmentalists say. Federal officials said the fact that the bird is protected by California as an endangered species is adequate.

Yellow-banded bumblebees, once common in the American Midwest and East Coast and in southern Canada, have declined due to pesticide use and large swaths of habitat lost to development,conservationists say. Federal officials said: "In the species’ current condition, there is occupancy across the majority of the yellow-banded bumble bee’s historical range."

The seaside alder tree lives in riparian and marshy areas in the East, where it may be threatened by salt-water intrusion via sea-level rise due to climate change. A separate population in Oklahoma is threatened by cattle grazing. But the tree has adequate, diverse habitat and populations, and is equipped to adapt to future change, the wildlife service said.

The Siskiyou Mountains salamander lives in the Klamath-Siskiyou region of Oregon and California, primarily in old-growth forests. It is threatened by U.S. Forest Service and Bureau of Land Management plans to increase logging, according to environmental biologists. Federal officials said that environmental groups had not presented "substantial" information to support their contention that fires, logging, mining and other factors were imperiling the salamander's existence.

Three creatures — the golden orb spider, smooth pimpleback mussel and Arapahoe snowfly — were determined to no longer be genetically distinct species. Curry, of the Center for Biological Diversity, said the government appeared to have properly relied on science that determined they are subgroups of larger species.

Trump has protected 18 species to date

The Endangered Species Act, signed by President Nixon in 1973, covers more than 1,600 species in the United States and its territories. The Trump administration has now protected 18 species and declined protections for more than 60 species, said Curry. Eighteen is the lowest number of species protected by any president this far into a first term, she said.

During the eight years of the Obama administration, 360 species were protected under the Endangered Species Act. Under President Bill Clinton's two terms, 523 species were protected.

Under President George H.W. Bush, who served one term, 232 species were protected. Under President George W. Bush, who served two terms, 62 species were protected.

During Ronald Reagan's eight-year presidency, 254 species were protected.

*Clarification: This story has been clarified to explain more clearly about the role economic impacts will play in the Endangered Species Act process and how protections will be extended to species listed as threatened.