PHOENIX - A long-held belief about old trees has been uprooted. A new study from the U.S. Geological Survey finds that trees' growth rates do not slow as they get older and larger; instead, they keep putting on mass along with their years.

According to study lead author Nate Stephenson, a forest ecologist with the USGS, if people did the same as trees, we'd weigh well over a ton by retirement age. For trees, the finding changes what we know about how they store carbon, and has implications for forest management.

"About for every pound of mass a tree puts on, it's absorbing and sequestering about a half-pound of carbon," he said, and added that old, large trees are better at storing and absorbing carbon from the atmosphere.

Stephenson pointed out that the rapid absorption rates mean old trees are the star players within forest carbon dynamics. And that's also of interest in terms of the changing climate.

"Change is going to happen no matter what, and if we want to project how forests are going to respond to that, we really have to get some of these key pieces right," he stated.

Trees around the world were studied for the report, more than 600,000 of them, from 400 different species on six continents.

Forests cover roughly 27 percent of Arizona's territory, or nearly 20 million acres.

The study has been published in the journal Nature, at Nature.com.




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Nevada scored high for its well-funded conservation programs and for the state's commitment to public land protections.

A new report by The Center for Western Priorities evaluated eight Western states within three categories - land protection and access, responsible energy development, and land use and planning for growth.

The Center's Policy Director Rachael Hamby said Nevada has done a good job of becoming an "assertive leader" as it relates to public land protection and conservation - especially with 67% of the state being made up of public lands, according to the Bureau of Land Management.

She added that Nevada was also the first state Legislature to endorse the global 30X30 Initiative, which is a plan to conserve 30% of nature by 2030 - to avoid what Hamby called a "biodiversity crisis."

"They've made progress towards that goal too, opening a couple new state parks," said Hamby, "and again this is a state doesn't always have as much of a surface area to work with - and this shows that is OK. You can be a conservation leader with your state-level policies in place for the lands that you do manage on behalf of Nevadans."

Hamby said the Silver State has also taken action to protect wildlife, including what she calls a "strong habitat framework" that is a direct result of an executive order signed in 2021 by former Gov. Steve Sisolak.

Nevada also passed a bill in 2021 that requires developers to consult with the Department of Wildlife on their subdivision plans and assess how projects will impact wildlife connectivity.

Nevada didn't have a legislative session in 2024, but it will have one in 2025.

Hamby said despite Nevada being in a good spot, there are still areas for improvement, such as responsible energy development.

Despite Nevada not being a major oil-producing or natural-gas producing state, it currently has no statewide setback requirements for oil and gas wells or any laws or rules on the books to reduce methane emissions.

Hamby said each state can celebrate its wins, but must also get to work where they're lagging.

"So hopefully the scorecard can help with identifying some area for growth in each state," said Hamby, "as policymakers are looking for ideas of what they might be able to do to advance conservation goals."

Hamby added that the positive economic implications of a transition to a clean energy economy will become even more evident in years to come.

Since the passage of The Clean Energy Plan in 2022, Nevada has seen more than 20,000 new jobs across the state.

When the Champlain Towers South collapsed in Surfside in 2021 taking 98 lives, it sent shock waves across South Florida. The tragedy has left lingering questions about the safety of coastal high-rises and whether the ground beneath them is as solid as once thought.

A new study by scientists from the University of Miami uncovered a troubling pattern: 35 buildings along the coastline from Miami Beach to Sunny Isles Beach are sinking, some at rates of up to eight centimeters in the past seven years.

Farzaneh Aziz Zanjani, a postdoctoral researcher at Washington University in St. Louis and the study's lead author, called the findings significant.

"We saw a correlation between the start of the subsidence and the nearby construction activities and we also found some correlation between the geology," Aziz Zanjani explained. "As we move from Sunny Isles to Miami Beach, the amount of subsidence is less."

Using satellite-based technology, the team tracked subtle ground movements which are otherwise invisible. Sunny Isles Beach, known for its luxury high-rises, showed the most dramatic rates of subsidence. The researchers believe the southern Florida geology with softer sandy layers within the limestone may be a factor.

For longtime residents, the study is unsettling. The idea some buildings may be sinking in a region already grappling with rising seas and stronger storms adds concerns about the future. Aziz Zanjani cautioned against jumping to conclusions.

"It doesn't necessarily mean that these buildings are unsafe," Aziz Zanjani pointed out. "This is beyond the scope of the study we had. It just shows that there is something happening under these buildings and it's related to geology and a lot more factors that we don't understand, and we need to do more research."

The research was motivated by the Surfside collapse but scientists found no evidence subsidence contributed to the tragedy. Still, Aziz Zanjani emphasized the study highlights the need for transparency and better monitoring of structural stability across the region. Aziz Zanjani's paper is open-access to the public.


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The Iowa Department of Natural Resources is training operators of Concentrated Animal Feeding Operations on the safest ways to apply manure to their fields and what to do if a spill happens. It is part of the state's effort to help reduce accidents and protect the environment.

Iowa produces about 50 million tons of manure every year or enough to fertilize roughly 17% of the state's cropland.

Jeff Prier, senior environmental specialist for the Iowa DNR, said the state is teaching commercial and smaller operators how to apply it safely by following a required manure management plan.

"When they go out to do their application, they need to comply with any separation distances to residence, church, business, school, public use area, water sources," Prier outlined. "Dependent on their application method."

Manure from Concentrated Animal Feeding Operations is known to pollute air and groundwater when it is not properly applied. Commercial operators said they are looking for more environmentally friendly ways to operate while trying to meet consumer demand for high quality meat. The deadline to apply for the DNR training is next week.

The DNR charges commercial operators $225 for a manure application permit and $175 for smaller operators. Prier noted it is a small price to avoid fines of between $3,000 and $5,000 for applying fertilizer without state certification.

"When they hear the numbers, they tend to open their eyes pretty big and think that's a pretty big number," Prier observed. "But the best reason is being in compliance with the rules and regulations and knowing what to do if there is a spill."

Prier, who has been overseeing training for 26 years, added given the amount of manure spread on Iowa farms every year, the number of spills is relatively small.


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