Green Group discussion

Prehistoric sea level rise in the Bronze Age, covered a forest off the modern shore of Wales. Now storms have caused the stumps to re-emerge.

http://www.bbc.com/travel/gallery/202...

Recreating extinct botanical species.

https://gizmodo.com/forget-the-woolly...

An active volcano's scars reveal the pattern of defoliation through general biodiversity loss as the island was colonised and animals were killed off.
https://www.ecowatch.com/volcano-miss...

Mediterranean olive trees are being attacked by a disease. The story does say 'ancient' trees; older trees of any kind are less likely to resist disease. Maybe young trees would recover.

https://www.ecowatch.com/olive-trees-...

Forests, provided they are not just marches of Sitka spruce, are providers of niches for biodiverse habitat. A study across Europe finds plant biodiversity in forests is declining. Nitrogen loving plants are becoming more persistent.

https://phys.org/news/2020-04-diversi...

"This video plants trees."

https://www.youtube.com/watch?v=_nDUx...

A massive tree fell in a forest in Ecuador, and the fact that a science project had been recording the immediate area beforehand allowed a new set of records to be taken.
Hummingbirds in particular showed up rapidly to exploit the gap and the light.

https://phys.org/news/2020-04-humming...

Claims that more CO2 will make trees grow better, ignore the fact of increased drought. Trees need sufficient moisture, some trees need a winter frost for seeds to germinate, other trees need cool for seeds to grow and seedlings to survive.

This new study in America examines drought stress, which I first saw during an Irish summer in the mid-1990s. Trees are getting killed faster than they can adapt, and older trees are not seeding. We have options, but we'd better start using these studies and putting better options into practice.

https://insideclimatenews.org/news/24...

A study of tree genetics across the Americas shows that temperate forests have more biodiversity within tree species than rainforests.
Seems obvious to me; jungles evolved with one kind of climate and temperate forests evolved for all kinds of climate.
Note that the Americas form a vertical spreading landmass compared to Eurasia, but trees live in horizontal bands of latitude.

https://phys.org/news/2020-05-rainfor...

" "What is unique about this study is that it uses DNA sequence information from thousands of tree species right across the Americas to give completely new insights into the countries and habitats where the major branches of the tree of life are found."

By examining the evolutionary structure of tree communities, the researchers tried to discover the main factors that prevent species expanding into new areas and environments.
The "fundamental divide" was found to be the presence or absence of freezing temperatures—which some plants cannot tolerate.

There was also an "evolutionary split" between trees that exist in moist and dry forests in the tropics. "

Natascha McElhone reads a passage about "Trees" by Herman Hesse, at the Royal Botanic Gardens, Kew.

https://www.youtube.com/watch?v=zkQ-6...

Tropical forests store carbon but for how long?

"Professor Marimon notes the clear limits to adaptation. "The study indicates a heat threshold of 32 degrees Celsius in daytime temperature. Above this point tropical forest carbon declines more quickly with higher temperatures, regardless of which species are present.

"Each degree increase above this 32 degree threshold releases four-times as much carbon dioxide as would have been released below the threshold.""

https://phys.org/news/2020-05-tropica...

The study notes that more biodiverse forests have a better chance of surviving as some species can adapt to warmer years more easily.
Biodiversity also functions within the species as individual trees can be possessed of genetic makeup that helps them adapt. This is not the case where trees have been cloned, or grown from seeds of a few trees for forestry.

Trees around the world are becoming shorter and younger. Older trees are being felled and their replacements (where they are planted) felled more quickly.

"In North America and Europe, where more detailed data was available, the researchers found that tree mortality doubled over that time, and a higher proportion of those deaths were older trees. Their findings suggest that on average, the world is losing old trees."

https://earther.gizmodo.com/trees-are...

For example, there are no more trees alive that can be felled to make the vaulted ceiling of Notre Dame as it was.

Some ash trees are genetically more resistant to the Emerald Ash Borer beetle than others. Since this beetle kills trees by the millions, scientists are working up a list of subspecies to replant. Mainly the problem has been seen in America due to imported material from Asia, but the beetle surfaced in Russia during the past few decades and is heading for Europe. The European ash trees are already under threat from ash dieback fungal disease.

https://phys.org/news/2020-05-scienti...

Clare wrote: "Some ash trees are genetically more resistant to the Emerald Ash Borer beetle than others. Since this beetle kills trees by the millions, scientists are working up a list of subspecies to replant. ..."

I can't believe how timely this piece is...we JUST scheduled an arborist to take down two of our ash trees from this. This is really interesting. Thank you for posting this Clare!

Sorry to hear about your trees!

I am an arborist in your parlance, a tree surgeon, where I live.
Anything about trees interests me.
I suggest replanting with a completely different species, here I would probably say hornbeam for similar functions.

Clare wrote: "Sorry to hear about your trees!

I am an arborist in your parlance, a tree surgeon, where I live.
Anything about trees interests me.
I suggest replanting with a completely different species, her..."

That's great advice...we're looking to put something in its place. I'm envious...I wish I knew more about trees! Thanks for the message and take care

Andy

Mass tree planting exercises sometimes don't get the follow-up care trees need to survive.

In Ethiopia, where the topsoil washes off each year and provides all that silt in the Nile, the people have been planting seedlings avidly but it doesn't always work. Here is a look at this year's plans and an unconfirmed assessment of last year.

https://phys.org/news/2020-06-snags-e...

"Belaynesh Zewdie, a forestry expert with the UN Development Programme in Buee, has seen firsthand how projects that lack community buy-in can go awry.

In the late 1980s, under the communist Derg regime, she was involved in a scheme to plant one million acacia trees in the northern Amhara region.

But the scheme was top-down and "forced", she recalls, and once the regime fell in 1991 angry residents cleared the trees to plough the land.

In recent years, Belaynesh has worked on a plantation and rehabilitation project in Buee that tries to deliver immediate and concrete benefits to those living nearby."

"As Oak Processionary Moth season begins, the Forestry Commission reminds people to be aware of the pest and report sightings."

https://www.gov.uk/government/news/pu...

A photo is included of the procession of caterpillars climbing around an oak trunk. These are a health hazard because of irritating hairs which can cause pain, skin rash, breathing hazard and allergic reactions. As such, this introduced pest is controlled with great care and in UK the observer has a duty to report the pest.

The site linked above is a UK Government website which requires you to accept cookies. Here is the UK Government Forestry Research website which has a great deal of information about these pests, including a photo of the nests and nibbled crown leaves.

https://www.forestresearch.gov.uk/too...

On the left margin is a list of other pests and diseases of trees with links to their pages.

I started reading about the pine-tree lappet moth and couldn't stop. The advisors are even doing genetic analysis to try to discover if a remnant population of native moth lives in the small Scots area, or if it was introduced and if so from where on the continent.

https://www.forestresearch.gov.uk/too...

They do not have a pest mention of the pine sawfly, which I have seen on a suburban Dublin Scots Pine. These mimic pine needles.

https://www.canr.msu.edu/news/check_p...
US report

https://www.rhs.org.uk/advice/profile...
UK report.
The UK page explains two pests: pine sawfly and fox-coloured sawfly. The pests are very similar but the trouble with the former is that they have two generations per year. So any regrowth on the tree gets stripped.

By examining the contents of a stomach of an anklyosaur, scientists are able to tell us what it ate, what time of year, how it helped or hindered regrowth after forest fires.

https://phys.org/news/2020-06-scienti...

Here is the original article on Dietary palaeoecology from the Royal Society.
https://royalsocietypublishing.org/do...

Mangrove forest are trees which store immense amounts of carbon right at the water's edge, providing security against tsunamis, sea rises, pollution and erosion.
Other benefits include clean water and biodiversity, and a source of food.

https://mangroveactionproject.org/

A mention in EcoWatch of how the above group is turning abandoned shrimp farms in Thailand back into the mangroves they used to be.

https://www.ecowatch.com/mangrove-eco...

Cicadas live underground as nymphs and suck sap from tree roots, then emerge as adults. Eggs are laid in cracks in branches and can cause twigs to split and break.
This is a cicada year in USA for the 17-year appearing variety.

https://earther.gizmodo.com/whats-up-...

You do need to turn the sound on for the short film!

A reminder that by preserving and planting appropriate forests, we preserve the original wildlife therein.
In this case, pine forests and the capercaillie.

https://cairngorms.co.uk/national-lot...

A panel of experts on climate change risks to forests met at Salt Lake City. They remind us that just planting trees won't be enough as the new forests will have to be conserved against increased risks that come with hotter climate.

https://phys.org/news/2020-06-forests...

This one's a bit technical but may interest any botany biochemists.

https://phys.org/news/2020-06-marvelo...

A technical tale about the coffee plant and caffeine gene.

https://phys.org/news/2014-09-coffee-...

Learn more about how trees make thorns on their branches.

https://phys.org/news/2020-06-scienti...

Plants in a mixed forest environment, like a Mexican jungle, have plenty of predators, from leaf-munching mammals to small wrigglies. As some predators favour some plants, scientists found it was in the plants' favour if they didn't smell distinctive.

https://phys.org/news/2020-06-camoufl...

""Easily distinguished odors are to the herbivores' advantage and plants' disadvantage," said Professor Phil Stevenson, a researcher at Britain's Royal Botanic Gardens, Kew.

"So, we have an information arms race. Plants want to avoid being located and eaten so do their best to smell like other plants."

Thursday's study was the first time scientists were able to analyze the interactions between such a wide variety of plants and insects, lead author Pengjuan Zu at Massachusetts Institute of Technology said.

Previous attempts to understand the cat-and-mouse evolution game between plants and insects relied on the study of only individual plant species in controlled environments.

This is a far cry from the ensemble of plant and insect species that coexist in real-life forests, the authors wrote."

Just planting trees to absorb carbon can harm native forests and biodiversity.

https://phys.org/news/2020-06-trees-t...

"A closer look reveals faults in the optimistic plans. For example, nearly 80 percent of commitments to the Bonn Challenge involve planting monoculture tree plantations or a limited mix of trees that produce products such as fruit and rubber rather than restoring natural forests. Plantations typically have significantly less potential for carbon sequestration, habitat creation and erosion control than natural forests. The potential benefit dwindles further if planted trees replace natural forests, grasslands or savannahs—ecosystems that have evolved to support unique, local biodiversity."

Trees and other plants near the Equator turn out to be growing at near the highest point of their temperature survival range.
So if it gets just a little hotter, the seeds won't germinate.
Thanks to Kew Gardens for this study.
Climate change will mean that by 2050 tropical plants could be going extinct in large numbers.

https://phys.org/news/2020-07-climate...

Measuring sap flow in trees. This is a slightly invasive procedure but the measurements for one tree could be used to inform about many. Trees in urban areas take up a great deal of surface water.

https://www.iros-uk.com/treevigourass...

The UK firm says it provides:
"Vigour assessment of newly planted trees.

Water uptake assessment for urban planting particularly within inner city and hard landscape areas

Assessment of vascular functions of older trees that are showing signs of stress

Real time data on water requirements for nursery stock

Sapflow assessment for Councils and Tree Officers, Forestry Organisations, Nurseries, Landscape Architects and Contractors, Arboreta and Private Owners"

Mexican fir.

"The Colima fir tree "has extremely low genetic diversity; it has the lowest known genetic diversity among all the species in the Abies genus in Mesoamerica and one of the lowest among all the species of trees on the planet," according to the authors of the proposal to recognize the tree as an endangered species. The area it occupies "is very limited": just 15,002 hectares (37,071 acres), or 0.007% of the territory of Mexico.

The Nevado de Colima volcano, which stands 4,260 meters (13,976 feet) above sea level, is one of only eight peaks that exceed 4,000 m (13,123 ft) in Mexico. It is only 40 kilometers (25 miles) from the Pacific Ocean and is considered an "evolutionary island" because the ecosystems in its high-altitude areas drive unique adaptations in species and are cut off from other ecosystems by hundreds of kilometers. The Colima fir tree is an example of the area's biological differentiation, according to Libertad Arredondo, a researcher and expert on the ecology of high mountains."

https://www.ecowatch.com/mexico-fir-t...

Urban trees - this article barely touches on their benefits but highlights some of their stresses.

https://www.ecowatch.com/trees-climat...

How plants evolved into many different species in the mountains now between India and China.
First thrust up your mountains. Then increase the rainfall to carve them. Instant spot for increased biodiversity.

https://phys.org/news/2020-07-ancient...

Not mentioned, crows evolved in the Himalayas and this is known as a launchpad. The Alps have also been a launchpad for species which then spread.

The newly found tallest tropical tree, in Borneo.
This article not only describes the giant and how it gained this height, but lets a local tree climber relate how it felt to ascend with a tape measure.

https://api-nationalgeographic-com.cd...

"This discovery is the first 100-meter tropical tree (and the world's tallest known flowering plant) recorded anywhere in the world. If it were laid along the ground the tree would be longer than a soccer field. The team named the tree “Menara,” which is Malaysian for tower. They estimated it weighs 81,500 kilograms, or more than the maximum takeoff weight of a Boeing 737-800, excluding roots.

It's possible an even taller tree is still waiting to be found in the region, the team notes.

These rainforest giants have been found growing in the Danum Valley Conservation Area, at the center of one of the best protected, and least disturbed, tracts of lowland rainforest left in South East Asia. Danum protects Borneo’s iconic and endangered orangutan, clouded leopard, and forest elephants. Danum is also, it turns out, providing refuge for the tallest known tropical trees in the world.

The record-breaking trees are all, so far, of the same species—yellow meranti. It is highly endangered, and IUCN red listed, having been harvested relentlessly for decades. While Sabah’s primary rainforest is under protection, yellow meranti felling still goes on elsewhere in Borneo—often to make molds for pouring concrete and cheap plywood. These incredible trees, each its own mini biodiversity hotspot hosting up to 1,000 insect, fungi and other plant species, can be reduced to planks in a sawmill in a few minutes."

The article contains a short clip of climbing and recording a giant redwood tree.

Viburnum is a shrub and the berries have been found to be made of lipid globules, not cellulose. They shine blue without pigment.

https://phys.org/news/2020-08-fruit-b...

A list of eleven facts about trees.

https://www.dw.com/en/11-surprising-f...

Microclimates occur when, for instance, one side of a valley gets sun and the other does not. Also, a hollow in an otherwise exposed mountain face. A rock pool - a slough on the prairie - a coppice of trees in open land.

https://www.ecowatch.com/microclimate...


"Forests provide us with some great examples. "The climate near the ground in a tropical rainforest is dramatically different from the climate in the canopy 50 meters [164 feet] above," says University of Montana ecologist Solomon Dobrowski in an email. "This vertical gradient among other factors allows for the staggering biodiversity we see in the tropics."

Likewise, scientists observed that a 2015 partial solar eclipse caused the air temperature of an Eastern European meadow to change more dramatically than it did in a nearby forest. That's because trees provide not only shade, but their leaves also reflect solar radiation. At the same time, forests tend to reduce wind speeds.

All those factors add up. A 2019 review of 98 wooded places — spread out across five continents — found that forests are 7.2 degrees Fahrenheit (4 degrees Celsius) cooler on average than the areas outside them."

Forests in Siberia are growing as the tundra warms, but forests in North America are being struck by insects and diseases.

https://phys.org/news/2020-08-north-a...

"The study is the first to quantify how carbon emitted from specific surface regions during the annual carbon flux affects the seasonal cycle of CO2 in the atmosphere: The planet essentially "breathes in" carbon during the spring and summer when trees and plants grow leaves and photosynthesize. It exhales in winter when vegetation goes dormant.

Knowing this seasonal flux gives researchers a picture of how productive different forest regions are and how much carbon they remove from the atmosphere.

The varied carbon flux across different forests of similar latitudes suggests that, while some forests, like those in Siberia, are continuing to increase their carbon uptake, others, like those in North America, may not. They may even absorb less as the climate changes."

More information: Xin Lin el al., "Siberian and temperate ecosystems shape Northern Hemisphere atmospheric CO2 seasonal amplification," PNAS (2020). www.pnas.org/cgi/doi/10.1073/pnas.191...
Journal information: Proceedings of the National Academy of Sciences

A short (7 min) YouTube video about how we need to have diverse forests with natural deadwood rather than monocrop plantations, if the trees are to survive climate change.
The setting is Germany and they don't explain insects, diseases etc.

https://www.youtube.com/watch?v=G-rN4...

As the Andes were being uplifted due to continental drift, the biomes changed. A massive petrified tree has been discovered, buried under turf on a now-treeless plain.

https://phys.org/news/2020-08-fossil-...

""This tree and the hundreds of fossil wood, leaf and pollen samples we collected on the expedition, reveal that when these plants were alive the ecosystem was more humid—even more humid than climate models of the past predicted," said Camila Martinez, a fellow at STRI, who recently finished her doctorate at Cornell University. "There is probably no comparable modern ecosystem, because temperatures were higher when these fossils were deposited 10 million years ago."

The anatomy of the petrified (permineralized) wood the researchers found is very much like wood anatomy in low-elevation tropical forests today. Indeed, the altitude then was probably only 2,000 meters above sea level."

Heat and drought stress make it hard for trees to fight off bark beetles. Now foresters can place a natural pheromone on trees to attract the predators of the bark beetles.

"The foreign messenger substances are therefore selective: The enemies of the bark beetles are attracted by these substances, but other bark beetles are not. In the best-case scenario, the foreign substance acts as a deterrent. As larvae, the ant beetles eat the early stages of the bark beetle that burrow into the wood. These predatory beetles also patrol the bark, where they catch and eat approaching bark beetles. In this way, they can prevent or reduce the infestation."

https://phys.org/news/2020-08-bambooz...

Europe's oldest known trees are all in Italy, and sessile oaks have now been radiocarbon dated to around 900 years. And going strong.

https://phys.org/news/2020-08-oldest-...

The Joshua Trees under a blood red sky.

https://phys.org/news/2020-09-mojave-...

"Hughson and Kaiser don't have early accounts to prove it, but they believe that grazing changed the dome from a more open savanna of native grasses studded with big old Joshua trees to a dense Joshua woodland that was undergrown by a mixture of native shrubs, bunch grasses and invasive red brome.

"The fire would not have burned so hot had it not been overgrazed and didn't have an increased fuel load," Kaiser said.

A less intense fire would have been less disastrous. As it is, of the estimated 1.33 million burned Joshua trees, Kaiser says fewer than 200,000 are topped by green leaves and have any chance of survival."

I wasn't familiar with the stinging tree, I'm pleased to say. Back away carefully!

"The tree's scientific name is Dendrocnide which literally means 'stinging tree'—a member of the nettle family which can be found in Australia from the Northern Rivers region of NSW, through Gympie QLD and all the way to the tip of the Cape York Peninsula.

"The Australian stinging tree species are particularly notorious for producing excruciatingly painful sting, which unlike those of their European and North American relatives can cause symptoms that last for days or weeks.

"Like other stinging plants such as nettles, the giant stinging tree is covered in needle-like appendages called trichomes that are around five millimetres in length—the trichomes look like fine hairs, but actually act like hypodermic needles that inject toxins when they make contact with skin," Associate Professor Vetter said."
https://phys.org/news/2020-09-native-...

More information: E.K. Gilding el al., "Neurotoxic peptides from the venom of the giant Australian stinging tree," Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.abb8828
Journal information: Science Advances
Provided by University of Queensland

Studying the dust on evergreen needles can tell you how much pollution is present; or I suggest you could study the lichen for the same answer. This scanning of trace elements also identifies magnetite, particles from brake lining and fuel burning.

https://phys.org/news/2020-09-evergre...

"Particulate matter in the air comes from many sources, including natural windblown dust, brake dust and the byproduct of burning solid or fossil fuel.

"That's stuff in the air," Lippert says, "and it's got to come out sometime."

When it falls out of the air some of it, of course, falls on tree leaves and evergreen needles. Some of the particles contain iron, with enough to be detectable by the kind of high-precision magnetometers that Lippert uses in his geological work. The iron-bearing particulate matter in the air can be too small to see, but magnetism, he says, is a way to see the unseen.

The papers made an impression on Rea-Downing, who saw Salt Lake City's air quality in stark contrast to the normally clean air of his native coastal California. He could easily apply the method in Lippert's research lab."

I have always found dust in trees, especially evergreens which act as natural traps and filters for the air particles. Climbing them could leave me quite dirty.

More information: Grant Rea‐Downing et al, Evergreen needle magnetization as a proxy for particulate matter pollution in urban environments, GeoHealth (2020). DOI: 10.1029/2020GH000286
Provided by University of Utah

Aspens are one of three trees which establish after glaciation. Now Colorado's aspens are declining due to heat.

https://phys.org/news/2020-09-colorad...

Primary forests.

"Primary forests are forests without any signs of past human use and where ecological processes are not disrupted by human influence. These forests are of outstanding ecological value. They are an irreplaceable part of our natural heritage and critical for conserving forest biodiversity. In Europe, where millennia of land use have transformed forested landscapes, very few such primary forests remain, and these are mostly found in remote and relatively unproductive areas.


Even if scarce and irreplaceable, many of these forests are not legally protected and continue to be logged in Europe. The newly released EU Biodiversity Strategy for 2030 explicitly recognizes the intrinsic value of primary and old-growth forests and the need to protect them. The question is: Which areas should be prioritized?"

https://phys.org/news/2020-09-europe-...

If anyone is particularly interested in trees, may I suggest they join Linked In and follow #trees - even without joining any groups they will find plenty of information is being posted. Posted by professionals in the field, who invite discussions and share their extensive knowledge.

WWF has a guest post and this person talks about trees and sustainability, in other words, for her industry that means forests equal paper.
She says she works for HP. Many, many people do not know what company initials represent, so HP is Hewlett Packard, a computer manufacturer based in America.

Google/ Wikipedia says:
"On November 1, 2015, as previously announced, Hewlett-Packard changed its name to HP Inc. and spun off Hewlett Packard Enterprise as a new publicly traded company.
Company acquired: Compaq, Palm, Inc., Apollo ...
Computer models: HP 2100, HP TouchPad
Subsidiary: Electronic Data Systems, 3Com, O...
Software: webOS, iPrint Photo, HP OpenView"


https://www.worldwildlife.org/blogs/s...