A boab tree in the Kimberley. Boab trees can live for thousands of years and their trunks hollow out as they get older.
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The leaves, when boiled, can be eaten like spinach. The seeds can be roasted for a coffee substitute, and the pulp can be fermented to make beer.
Lake sediment tells an ancient story of trees, soil – and disaster.
Dr. Niklas Leicher, University of Cologne
Thousands of years of history tells the same story over and over: you ignore soil at your peril.
How many lakes are in Alaska? Thermokarst lakes on Alaska’s North Slope are self-similar and fractal.
Painting by Cherissa Dukelow
What do earthquakes, wealthy Italian families and your circulatory system have in common? Scientists use fractals, self-similarity and power laws to translate from local to global scales.
“Vic Stockwell’s puzzle”: a close but anciently separated relative of the eucalypts.
Frank Zich
Stockwellia has links back to the epoch before Australia separated into its own continent and was mostly covered in rainforest.
The short answer is that leaves fall off trees when they aren’t doing their job any more.
Emily Nunell/The Conversation CC-NY-BD
Leaves fall off trees when they aren’t doing their job any more. If there isn’t enough water, the leaf can be damaged and stop working.
The lonely Malham Ash at dawn in Yorkshire Dales National Park.
PhilMacDPhoto/Shutterstock
A new study has calculated the tremendous cost of ash dieback to the UK economy.
Just off Washington Square in New York City.
Frej Berg/Flickr
Trees clean urban air, store carbon, slow floodwaters and can be used to design safer streets. Scholars are starting to calculate what these services are worth – a fitting topic for Arbor Day.
Autumnal displays may be dimmed in the future.
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Record-breaking summer heat might mean trees delay and mute their autumn hues.
In Australia you can have any tree you want, as long as it’s a eucalypt.
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Eucalypts have been in Australia for 45 million years. But hundreds of species appeared more recently than previously thought.
As climate change threatens Australian trees, it’s important to identify which are at risk.
Nicolás Boullosa/flickr
Climate extremes are killing Australian trees, but we don’t know where they’re dying. Scientists are asking the public to use their phones to help.
The Conversation
Walking towards this tree, which grows only on a select few mist-shrouded mountainsides in Queensland, can feel like stepping into a prehistoric dinosaur-filled fantasy.
In 1919, 1,376 new Norway Maples were planted along streets in Brooklyn.
Department of Parks of the Borough of Brooklyn, City of New York
In 1910, along one 45-block stretch of New York City’s Fifth Avenue, there were only 13 trees.
Nowhere for wildlife to Hyde.
I Wei Huang/Shutterstock
Keeping urban habitats such as parks neat and tidy by removing dead wood and leaves is driving the species which live there to extinction.
Christmas shouldn’t be the only time of the year to have greenery in the household.
Rain0975/Flickr
Studies show the presence of natural living things in homes improve wellbeing. So why not have your own version of a Christmas tree all year round?
Green Christmas.
Happy Hirtzel/Shutterstock
Whether plastic or natural, Christmas trees are generally bad for the environment. However, a new chemical process could recycle dead trees into all kinds of useful products.
Scotch pines on a Christmas tree farm in northern Michigan.
Bert Cregg
Both natural and artificial Christmas trees have environmental impacts, but they’re not major. What matters most is what happens to the trees after the holidays.
Wes Mountain/The Conversation
It takes a eucalyptus tree more than a hundred years to develop hollows suitable to shelter Aussie animals, and just moments to cut it down.
RoberG/Shutterstock.com
Valuing nature is hardly natural.
Snowpack protects tree roots and soil from harmful freeze/thaw cycles.
Rebecca Siegel
Climate change is shrinking winter snow cover in Northeast forests, which protects tree roots and soil from repeated freezing and thawing. This could stunt tree growth and forest carbon storage.
India has developed a pioneering national agroforestry policy.
Suleman Merchant/Shutterstock
If we need more trees, many will have to be introduced into managed agricultural mosaic landscapes.