Real Life Lorax Listening to the Oldest Trees

Music of the Trees.

Some will find this a bit woo, that’s fine. We need it all.
If only tree planting was all we needed to do to reverse climate change, that would be great, and for some, the “plant trees” meme is a substitute for doing the hard work of cutting heat trapping gases.
Research, however, (below) makes it clear that tree planting, while a critical component of climate response, must go along with rapidly cutting emissions.

I’ve not met Dave Milarch, but he’s got this operation going in Northern Michigan to preserve the genomes of the world’s largest and most long lived trees. Gotta say my hat’s off to that.

Inside Climate News:

Most climate-concerned people know that trees can help slow global warming by removing carbon dioxide from the atmosphere, but a recent study published in the journal Science shows the climate cooling benefits of planting trees may be overestimated.

“Our study showed that there is a strong cooling from the trees. But that cooling might not be as strong as we would have thought,” Maria Val Martin, a senior lecturer at the University of Sheffield in the U.K. and the senior author of the research article, said.

Darker forests can warm the Earth because they reduce the albedo of the land they cover, meaning they absorb more sunlight and reflect less solar radiation back into space. So more heat is held by the Earth’s surface.

In addition, trees play a more complex role in the Earth and its atmosphere than just sequestering carbon dioxide. They also release organic compounds, such as isoprene and monoterpenes.

These compounds can react with various oxidants, including the hydroxyl radical that breaks down methane, a greenhouse gas that is roughly 80 times more potent at warming the climate than carbon dioxide over a 20-year period. The reaction with the organic compounds released by forests leads to a reduction in hydroxyl concentrations, which decreases the destruction of methane and increases the concentrations of the greenhouse gas in the atmosphere.

Given methane’s potency in warming the climate, even a modest change can have a significant impact on atmospheric warming, said James Weber, a lecturer at the University of Reading in the U.K. Consequently, the climate benefits from planting trees will be greater if methane is also being reduced in the atmosphere through other means.

“Reforestation has a part to play, but it will be more efficient if we do it while also cutting greenhouse gas emissions and anthropogenic pollution,” Weber said. 

The compounds that trees emit also react to nitrogen oxides, creating the greenhouse gas ozone, which can warm the atmosphere, but can also lead to the production of aerosol particles that reflect solar radiation back into space, creating a cooling effect.

“Really, [we’re] saying let’s do it, but let’s do it as part of a broader package of sustainable measures, not ‘planting trees is our only option,’” Weber said.

And not just mono crop Truffula trees, either.

Nature Conservancy:

Planting forests with diverse species can help ensure their success, according to a new study published May 18 from the Smithsonian Environmental Research Center (SERC) and The Nature Conservancy. The study is the result of a decade of research from BiodiversiTREE, a large-scale reforestation project at SERC designed to run 100 years, testing the effects of different tree planting strategies on sapling survival and other ecosystem functions.

Forests are naturally diverse, and this diversity of plant species brings an array of benefits: pest and disease resistance, resilience to climate change and increased wildlife habitat. However, nearly all forest plantations, and some restoration projects, are planted as monocultures—where a single plant species is grown on the land. This practice leaves both managed and unmanaged forests ecologically and economically vulnerable to changing conditions. Another disadvantage of monocultures is the risk of planting failure—where a sapling fails to thrive—and early mortality.

Hundreds of scientific studies have shown that biodiversity enhances ecosystem function, suggesting that diversity in tree plantings could improve their survival outcomes. Yet there have been few tests of this hypothesis on trees. Scientists designed BiodiversiTREE to test whether tree diversity impacts ecosystem function—the largest experiment of its kind in North America.

In 2013, scientists and 100 volunteers created BiodiversiTREE by planting 20,000 saplings on former agricultural land near Chesapeake Bay. In some sections the scientists and volunteers planted a single species, and in others four or 12 species. Around 8,000 trees planted in the project were monitored yearly for the first three years, and then every two to three years thereafter.

Ten years in, the results showed that reforestation projects with diverse species are more likely to include species that thrive at the planting site, lowering the risk of planting failure.

“Even planting four species instead of just one significantly reduced variation in survival in our plots, showing that small increases in diversity could have large impacts on the success of tree planting efforts,” said Rachel King, forest ecologist at SERC and lead author of the study, published in the journal Restoration Ecology.