Tag Archives: trees

Trees provide hundreds of millions of dollars in services to cities for free, paper reports

Megacities gain some US$500 million in services from trees each year, a new paper reports. That sum could potentially be increased by up to 85%, simply by planting more trees, the researchers add.

Awesome trees landscape.

Image credits michalhlavac204 / Pixabay.

Trees are good business for cities. They filter air and water pollutants and supply other critters that maintain city ecosystems with room and board. An international team of researchers wanted to quantify how these services translated to avoided costs in the world’s ten largest megacities, which house nearly 10% of the world population. Even better, they also report that these cities can increase that sum by around 85% simply by planting more trees.

Trees — they keep cities running

Trees underpin urban ecosystems and have an annual median value of US$ 505 million, the team reports, equivalent to saving $1.2 million with every square kilometer of trees planted. Crunch those numbers down and it means that everybody living in such a city would have to pay an average of $35 per year for these ecological services if the trees weren’t there, the team estimates. It doesn’t sound like a lot on on a per capita basis, but seeing as a ‘megacity’ is defined as housing in excess of ten million people, that adds up to a huge pile of money overall.

So how can a tree help people save money? We all know they help improve air quality by scrubbing CO2, but they also perform a wide range of often-overlooked services which play a direct role in making our cities livable. For example, their leaves filter harmful airborne particles out of the atmosphere — something your lungs are definitely thankful for. Everybody’s scrambling for the shade they provide during a heatwave, but trees further help mitigate warm weather by transpiring water vapor. Their shade helps keep buildings and pavement cool (meaning lower costs on air conditioning and more comfortable walks outside), prevent soil erosion, and mitigate runoff during storms.

In other words, trees are really good news for cities and the people living there. In their absence, we’d have to find (and pay for) alternate ways to provide these services in our cities or risk them becoming unlivable expanses of concrete. And the simplest way to save even more, according to Dr. Theodore Endreny of the College of Environmental Science and Forestry (ESF) in Syracuse, New York, the study’s lead author, is to plant even more of them.

“Megacities can increase these benefits on average by 85 percent,” Endreny said. “If trees were to be established throughout their potential cover area, they would serve to filter air and water pollutants and reduce building energy use, and improve human well-being while providing habitat and resources for other species in the urban area.”

Tree city.

They also supply a lot of ‘pretty’.
Image credits Timofey Iasinskii.

To reach the figures reported on in this study, the team estimated existing and potential tree cover in each city and compared that to the ecosystem services the plants provide. Their analysis spanned 10 megacity metropolitan areas across different biomes over five continents. The cities used in the study were Beijing, Buenos Aires, Cairo, Istanbul, London, Los Angeles, Mexico City, Moscow, Mumbai, and Tokyo. As far as ecosystem services are concerned, the team estimated the benefits trees bring to the table in reducing air and water pollution, their effect in mitigating runoff from precipitation, absorption of carbon emissions, and finally building heating and cooling energy savings associated with the plants — both indirect, such as shade, and indirect such as transpiration which helps take the edge off during heatwaves.

“Placing these results on the larger scale of socio-economic systems makes evident to what extent nature supports our individual and community well-being by providing ecosystem services for free,” said Professor Sergio Ulgiati of University Parthenope of Naples, co-author of the paper.

“A deeper awareness of the economic value of free services provided by nature may increase our willingness to invest efforts and resources into natural capital conservation and correct exploitation, so that societal wealth, economic stability and well-being would also increase.

While the sum smaller settlements save on trees is likely smaller, they also house fewer people, meaning that the per capita figures reported by the team probably aren’t that different for smaller towns or cities. And, given the looming threat of climate change and deadly heat waves in both Europe and the United States, trees might be the last line of defense in keeping our cities — if not pleasant — at least habitable.

Practical reasoning notwithstanding, I think we can all agree that cities simply feel better when they’re full of greenery. Plus, we can turn their hand (branches? roots?) and erect some strikingly awesome elf-like architecture — or chic residences. Ample reasons to plant them as often as we can.

The paper “Implementing and managing urban forests: A much needed conservation strategy to increase ecosystem services and urban wellbeing” has been published in the journal Ecological Modelling.

Forest.

Trump Forest wants to compensate for the POTUS’ climate policy by planting 100 new billion trees

In an effort to offset the US’s move away from the Paris goals, a trio of veteran climate campaigners want everyone to join in on planting the Trump Forest. A global forest of over 100 billion new trees.

Forest.

Image credits David Mark.

The plan took off because of the organizers’ frustration over the POTUS “ignorance” on climate science, they say. Seeing as the president’s views on issues such as climate change won’t improve, they set out to beef up our planet’s ability to soak up the damage. Under the project, christened Trump Forest, people can either plant locally or pay for trees to be planted in a number of poorer countries which are most at risk from shifting climate.

All in all, the organizers say they need to plant a forest “the size of Kentucky” to balance out the effect Trump’s policy will have on the planet.

Billions of trees

The New Zealand-based project took off in March this year and has gained backing from around 730 people all around the world. Some 15,000 trees were pledged in the first month alone, and it’s since gone just shy of 200,000. The backers paid for all these trees to be planted in forest restoration projects in Madagascar, Haiti, Ethiopia, and Nepal, or bought and planted a tree themselves and sent a copy of the receipt to the project.

The organizers say they hope to tap into the growing global sense of frustration over the administration’s climate policy, which has seen the US leave the Paris agreement and undo many Obama-era climate policies.

“We’ve met some of the people on the front lines of climate change in Bangladesh, Mongolia and in other countries, and we found it extremely upsetting that Mr Trump’s ignorance is so profound,” said Adrien Taylor, a co-founder of Trump Forest.

“So we started to do something about it. Only a small percentage of the world voted him in, but we all have to deal with the consequences of his climate ignorance.”

The goal of Trump Forest is to offset 650 megatonnes of CO2 equivalent by 2025, which is their estimate of the effect Trump’s presidency will have. All in all, that means they need to plant over 100 billion new trees. That’s a massive undertaking, but the organizers are confident it can be done. They’ve had “a bit of hate mail” from people who support Trump’s policies, but generally have seen a lot of public support for the initiative, despite concerns that the project’s name goes to stroke the president’s ego.

“We want to plant a global forest that will offset all of the emissions that the Trump administration puts in the atmosphere. It sounds a bit ridiculous but it is completely feasible,” said Dr Daniel Price, another co-founder.

“We kind of want him to love the forest; this is his forest after all. We would love it if he tweeted about it,” Taylor added. “All we’re trying to do is pick up the slack he has created and do the work for him. So if he wants to take ownership of this forest just like Trump vodka and Trump Tower, we would welcome that; the phone line is open. So, Mr President, if you are reading this…”

Of course, they’re still a ways away from achieving their goal, but grassroots movements like this can make a significant difference and they’re something everyone can get involved in, setting a positive example. Lord knows we need them such examples.

Trees by themselves probably won’t stop climate change for us, no matter how many we plant. But they’d certainly help. So if you want to be part of the global forest, visit Trump Forests‘ website and see how you can help.

How old is the oldest tree?

Just like Treebeard the Ent claims to be the oldest creature in Middle Earth, trees are among the oldest living beings on real Earth. The oldest tree depends on what you count as a “tree” but ranges from 5,000 to 80,000 years. Now that’s a long time!

Trees have been around for such a long time because a long life means that there is more opportunity to reproduce. Therefore a longer life has been evolutionarily selected for, and trees have unique abilities such as being able to replace organs, part of the tree being able to survive even if the whole is damaged, and their array of defense compounds.

There are two types of trees that we need to consider when discussing tree age: individual trees and identical clonal colonies. Clonal colonies differ from individual trees in that each tree in a colony is genetically identical and connected via a root system, so you can consider them as one organism although there might be many trees. Clonal colonies might be old as a whole, but no single tree is particularly old.

Single trees

Single trees can be measured directly for how old they are. Usually, researchers count tree rings or estimate their age from the tree’s size and growth rate. The trunk shows how old the whole tree is (this might sound obvious, but we will see later that it isn’t).

The oldest tree in the world is this species, a bristlecone pine. Image credits: daveynin.

Great Basin bristlecone pine trees (Pinus longaeva) from California and Nevada top the list of the oldest trees. There are several that are around 5,000 years old. The oldest is 5,066 years old and located in the White Mountains of California. The second oldest, called Methuselah, is 4,849 and also in California. Their exact locations are kept a secret to protect them. Prometheus, which would be the third oldest was cut down in 1964 by a researcher who wasn’t aware how old it was.

These pines aren’t the only trees that can live a long time; cypress, olive trees, and yew tree have also been found to be over 3000 years old. There could be other really old trees, but they haven’t been measured yet.

Clonal colonies

Clonal colonies are composed of genetically identical trees that are connected by a root system. Though the trees themselves might not actually be so old, the root system and the whole organism could be much older than any individual tree. So if you aged a single tree then you would think that the tree isn’t so old, but if you aged the root system, such as with radiocarbon dating, it can be much, much older.

Pando is one of the largest, oldest living organisms in the world. Image credits: Mark Muir.

Here are a few examples of very old clonal tree colonies. A colony of quaking aspen trees (Populus tremuloides) in Utah called Pando is believed to be one of the oldest and largest organisms in the world. It covers 106 acres (43 hectares), contains around 40,000 trees, and it is at least 80,000 years old. It has been cloning itself for that period of time. However, the individual trees in Pando are only about 130 years old. The Jurupa Oak in California is the second oldest at about 13,000 years old.

Old Tjikko, a Norway Spruce (Picea abies), in Norway is often called the world’s oldest tree. However, the distinction needs to be made that it is actually a clonal tree, and if you compare it to Pando then it’s still a baby colony. The tree lives to be about 100 but Old Tjikko’s root system is 9,550 years old. It is likely the only living trunk left from a former colony which started growing in the last Ice Age. Four generations of remains were found at the site, all genetically the same.

Old Tjikko, the stem itself isn’t so old (about 100 years), but the as a whole it is about 9,550 years old. Image credits: Karl Brodowsky.

All in all, these trees are very old. When Pando started growing, modern humans were just spreading to Asia from Africa. The oldest individual tree started growing at about the same time as the Stonehenge was first built, Troy was founded, and the first pharaohs reigned. These trees still stand as a remnant from a time long past.

 

 

 

 

trees global warming

We can’t count on trees to solve our global warming mess — there’s just too much CO2 out there

trees global warming

Credit: Pixabay.

Massive reforestation can’t save us from runaway global warming, despite what intuition might tell us. According to a recent study which simulated CO2 removal from a biosphere point of view, biomass plantations would be inadequate in steering us away from a potentially disastrous 2 degrees Celsius global warming scenario. Instead, we have to cut off fossil fuels immediately and plant biomass at the same time if we’re to have a winning shot at this.

Trees — don’t overestimate them

We all know deforestation is running rampant all over the world. According to the World Resources Institute, more than 80 percent of the Earth’s natural forests already have been destroyed. Up to 90 percent of West Africa’s coastal rain forests have disappeared since 1900. This destruction is continuing on a daily basis. The U.S. State Department estimates that forests four times the size of Switzerland are lost each year because of clearing and degradation. That’s because every year our cities grow bigger, and so do our crop fields and industrial centers to support an ever growing and affluent population.

Here’s what the forest cover in Central Europe used to look like some 1,100 years ago.

Credit: Michael Williams (2006) – Deforesting the Earth From Prehistory to Global Crisis, An Abridgment. University Of Chicago Press.

Credit: Michael Williams (2006) – Deforesting the Earth From Prehistory to Global Crisis, An Abridgment. University Of Chicago Press.

Trees are incredibly useful. They provide shelter and food for millions of species, enrich the soil, and — perhaps most importantly — suck out CO2 and expel O2. That’s literally the reverse of human respiration and for millions of years, this delicate interplay has worked out just fine for everyone. But then humans started digging and burning billions of tonnes of carbon that was stored in the crust for ages. Coupled with massive deforestation, human activity has released so many greenhouse gases into the atmosphere that the world is now nearly 1 degree Celsius warmer than at the start of the Industrial Revolution.

Though alarmed, some people might feel comfortable knowing that we can always replant our forests to offset all the damage we’ve caused in the last 150 years. But that’s just wishful thinking, according to an international team of researchers who simulated what would happen if we grew biomass under three scenarios: business as usual (unabated burning of fossil fuel resources), Paris Agreement (190+ countries pledged to reduce or cap emissions on a case by case basis. For instance, the U.S.  pledged to lower emissions by at least 26 percent below 2005 levels by 2025), and very ambitious CO2 reductions.

The team found that if we continue to burn fossil fuels at this current rate, the number of trees we’d need to plant would be simply staggering and impractical. Even if we’d plant nothing but poplar trees or switchgrass, which have some of the highest density of stored biomass (50% carbon), under this scenario the size of the plantation would replace natural ecosystems around the world almost completely.

“If we continue burning coal and oil the way we do today and regret our inaction later, the amounts of greenhouse gas we would need to take out of the atmosphere in order to stabilize the climate would be too huge to manage,” says Lena Boysen from the Potsdam Institute for Climate Impact Research (PIK), Germany, lead-author of the study published in a journal of the American Geophysical Union, Earth’s Future.

In the case of scenario #2, even if all the Paris pledgers put their money where their mouth is, we’d still be in trouble. The biomass plantations required by mid-century to extract all that remaining excess CO2 from the atmosphere would be enormous. We’d have to replace natural ecosystems on fertile land the size of more than one-third of all forests we have today on our planet. If that’s not an option, we can always convert a quarter of the land used for agriculture into biomass plantations. But in doing so, we’d seriously jeopardize global food security.

Lastly, if the world was very serious about climate change and ambitiously decided to reduce carbon emissions, then fierce competition for land and food could be less pronounced than in the other two scenarios. However, even in this scenario, we’d have to use high-tech carbon-storage-machinery that captures more than 75 percent of extracted CO2 to limit warming to around 2°C by 2100.

“As scientists we are looking at all possible futures, not just the positive ones,” says co-author Wolfgang Lucht from PIK. “What happens in the worst case, a widespread disruption and failure of mitigation policies? Would plants allow us to still stabilize climate in emergency mode?”

“The answer is: no. There is no alternative for successful mitigation. In that scenario plants can potentially play a limited, but important role, if managed well.”

The fact is, there is no simple solution such as ‘planting more trees’ to such a complex problem like global warming. Consider the following:

Typically, a tree absorbs as much as 48 pounds (21 kg) of carbon dioxide per year and can sequester 1 ton of carbon dioxide by the time it reaches 40 years old. The average North American generates about 20 tons of CO2-eq each year, which means every year you’d need to plant about 500 trees to offset your own carbon footprint, that’s not taking into account the time it takes for a tree to mature and reach the optimal carbon-sinking age. If you’re a New Yorker and need to fly to Berlin, your seat is responsible for generating 10,285 pounds (4,675 kg) of CO2. Your 8.5-hour-long flight just offset roughly 223 trees!

“Our work shows that carbon removal via the biosphere cannot be used as a late-regret option to tackle climate change. Instead we have to act now using all possible measures instead of waiting for first-best solutions,” says co-author Tim Lenton of the University of Exeter, UK.

“Reducing fossil fuel use is a precondition for stabilizing the climate, but we also need to make use of a range of options from reforestation on degraded land to low-till agriculture and from efficient irrigation systems to limiting food waste.”

The big takeaway here is that mitigating climate change involves all state actors working in coordination and a number of tools. Planting biomass is definitely in our toolset but can’t work alone by itself. We also need renewable energy, an immediate shutdown of fossil fuel activity, as well as high-tech carbon storage and capture.

“In the climate drama currently unfolding on that big stage we call Earth, CO2 removal is not the hero who finally saves the day after everything else has failed. It is rather a supporting actor that has to come into play right from the beginning, while the major part is up to the mitigation protagonist,” says co-author Hans Joachim Schellnhuber, Director of PIK. “So this is a positive message: We know what to do — rapidly ending fossil fuel use complemented by a great variety of CO2 removal techniques. We know when to do it — now. And if we do it, we find it is still possible to avoid the bulk of climate risks by limiting temperature rise to below 2 degrees Celsius.”

Wildfire

Up to 80 percent of all wildfires in the U.S. are started by humans

Wildfire

Credit: Pixabay.

Five out of six wildfires which occurred in the U.S. in the past two decades can be traced back to human activity, a new study found. Human-caused blazes, either on purpose or by accident, have tripled the length of the wildfire season causing it to start earlier in the East and to last longer in the West.

Jennifer Balch, a fire ecologist at the University of Colorado, and colleagues analyzed wildfires occurrences in the country between 1992 to 2011. The researchers found a staggering 1.3 million fires were started by humans, mostly due to trash burning which explained 29 percent of human-started fires. Around 21 percent of fires were due to arson or just as much as there were due to lightning. Another 11 percent can be traced to faulty or misuse of equipment.

Strikingly, one out of five wildfires occurred during the 4th of July. That’s not to say these were the most damaging. While humans are the prime drivers of forest wildfires, we’re responsible for only 44 percent of acres burned.

This chart put together by the researchers show human-triggered wildfire incidence around the country. Credit: PNAS.

This chart put together by the researchers show human-triggered wildfire incidence around the country. Credit: PNAS.

The most human-triggered wildfires can be found in the Southeast. For instance, in Kentucky, West Virginia, and Tennessee fire seasons lasted for more than 200 days on average in a year. In these states, 99 percent of all wildfires are caused by humans. That’s because forests in these states don’t catch fire easily.

“The role that humans play in starting these fires and the direct role of human-ignitions on recent increases in wildfire activity have been overlooked in public and scientific discourse,” the scientists wrote in the Proceedings of the National Academy of Sciences.

Humans are also indirectly responsible for an increase in both frequency and length of wildfires by driving climate change as a result of releasing greenhouse gases in the atmosphere. Four of the worst wildfires since 1960 happened in the last decade, among which 2015 is considered the worst wildfire year on record. A growing number of homes in or near major forests is to blame for this dramatic rise in fires but hotter, drier seasons shouldn’t be ignored. In 2016 alone, wildfire damages amounted to two billion dollars.

[ALSO See] The different types of forests

Generally, wildfires are good for ecosystems. These regenerate the forest, revitalize the watershed, renew the soil, and reset the clock for the ecosystem. Many forests such as pine barrens or lodgepole pine forests can’t even survive without fires since the trees are adapted to only produce seeds following a major fire event. That being said, there’s clearly nothing natural in this recent trend and people should definitely act more responsibly when going out in the forest.

The different types of forests: everything you need to know

Forests cover 1/3 of the earth’s surface and contain an estimated 3 trillion trees. Forests exist in dry, wet, bitterly cold, and swelteringly hot climates. These different forests all have special characteristics that allow them to thrive in their particular climate.

Broadly speaking, there are three major forest zones that are separated according to their distance from the equator. These are:

  • the tropical,
  • temperate,
  • and boreal forests (taiga).

There are also more specific types of forests within these larger regions.

World forest cover. Image credits: NASA Earth Observatory

Tropical forests

Tropical rain forests grow around the equator in South America, Africa, and Southeast Asia. They have the highest species diversity per area in the world, containing millions of different species. Even though they cover only a small part of the earth, they house at least one half of all species. The temperature is stable year-round, around 27°C (60° Fahrenheit). As you can tell from the name, it rains a lot in these forests. Most tropical forests receive at least 200 cm (80 inches) of rain in a year. Tropical forests generally have a rainy and dry season.

Tropical rain forests contain millions of species. Image credits: Thomas Schoch

The high temperatures, abundant rainfall, together with twelve hours of light a day promotes the growth of many different plants. One square kilometer (0.6 miles) can have up to 100 different tree species. Broadleaf trees, mosses, ferns, palms, and orchids all thrive in rain forests. The trees grow very densely together and the branches and leaves block most of the light from penetrating to the understory. Many animals adapted to life in trees — such as monkeys, snakes, frogs, lizards, and small mammals — are found in these forests.

Map of global tropical (dark green) and temperate/subtropical (light green) rainforests. Image credits: Ville Koistinen

The soil can be several meters deep, but due to nutrient leaching, it lacks most of the essential nutrients for plant growth. The thin topsoil layer contains all the nutrients from decaying plants and animals, and this thin layer sustains the many plant species in the forest. One might think that the soil would be very rich because it supports so much life, but when tropical forests are clear-cut, the soil is useless for agriculture after only a few years — when the topsoil becomes depleted.

Different subcategories within tropical rain forests

  • Evergreen: rain year-round, no dry season
  • Seasonal: vegetation evergreen, short dry season,
  • Dry: long dry season in which trees lose leaves
  • Montane: most precipitation from mist or fog that rises (also called cloud forests), mostly conifers
  • Tropical and subtropical coniferous: dry and warm climate with conifers adapted to variable weather
  • Sub-tropical: north and south of tropical forests, trees adapted to resist summer drought

    Mindo cloud forest in Ecuador. Image credits: Ayacop

Temperate forests

Temperate forests occur in the next latitude ring, in North America, northeastern Asia, and Europe. There are four well-defined seasons in this zone including winter. In general, the temperature ranges from -30 to 30°C (-22 to 86 F) and the forests receive 75-150 cm (30-60 in) of precipitation per year. Deciduous — or leaf-shedding — trees make up a large proportion of the tree composition in addition to some coniferous trees such as pines and firs. The decaying fallen leaves and moderate temperatures combine to create fertile soil. On average, there are 3-4 tree species per square km. Common tree species are oak, beech, maple, elm, birch, willow, and hickory trees. Common animals that live in the forest are squirrels, rabbits, birds, deer, wolves, foxes, and bears. They are adapted to both cold winters and warm summer weather.

Global temperate deciduous and mixed forests. Image credits: Terpsichores

Temperate evergreen coniferous forests are found in the northwestern Americas, South Japan, New Zealand, and Northwestern Europe. These forests are also called temperate rain forests because of the large amount of rainfall they see. The temperature stays pretty constant throughout the year, with a lot of precipitation, 130-500 cm (50-200 in). All this rain creates a moist climate and a long growing season, which results in very large trees. Evergreen conifers dominate these forests. Common species are cedar, cypress, pine, spruce, redwood, and fir. There are still some deciduous trees such as maples and many mosses and ferns — resulting in a Jurassic-looking forest. Common animals roaming the woods are deer, elk, bears, owls, and marmots.

Coastal temperate rainforest. Image credits: Sam Beebe

Subcategories within temperate forests

  • Moist conifer and evergreen broad-leaved: mild wet winters and dry summers
  • Dry conifer: at higher elevations, little rainfall
  • Mediterranean: located south of temperate regions around coast, almost all trees evergreen
  • Temperate broad-leaved rainforest: mild, frost-free winters, lots of rain throughout the whole year, evergreen

Boreal forests

Boreal forests, also called taiga, are found between 50 and 60 degree of latitude in the sub-Arctic zone. This area contains Siberia, Scandinavia, Alaska, and Canada. Trees are coniferous and evergreen.

Global boreal forests. Image credits: Terpsichores

There are two seasons here: a short, moist, mildly-warm summer and a long cold dry winter. Temperatures range from -40 to 20°C (-40 to 68° Fahrenheit). Precipitation is usually delivered as snow because it is so cold, 40-100 cm (15-40 inches) each year. The ground is comprised of a very thin layer of nutrient-poor, acidic soil. The canopy lets very little light through so there is usually little growing in the understory. Evergreen conifers with needle leaves that can stand the cold, like pine, fir, and spruce trees, live here. Animals that live in these forests can withstand long periods of cold temperatures and usually have thick fur or other insulation — among them are moose, bears, lynx, wolf, deer, wolverines, caribou, bats, small mammals, and birds.

Aerial view of a boreal forest. Image credits: Cephas

The world’s forests are incredibly diverse and act as a carbon sink! They should be protected for their beauty and functionality.

Mindblowing fact of the day: sharks are older than trees

This 240-million-year-old fish is Helicoprion. It goes to show just how much sharks have been experimenting with their arsenal. Credit: Sharkopedia.

Trees as we familiarly know them today — a primary trunk, large height, crown of leaves or fronds — didn’t appear on the planet until the late Devonian period, some 360 million years ago. You might be surprised to learn that sharks are older than trees as they’ve been around for at least 400 million years.

Sharks have been around truly for a very long time, proving their resilience. They’ve survived all five global mass extinctions that knocked 80% of the planets mega– fauna out of existence. In the worse such event, 251 million years ago, as many as 95% of species were killed.

Tracing the evolution of sharks can be frustrating. Because they have a cartilaginous skeleton, only a few body parts can be preserved as fossils, making it difficult to understand what ancient sharks were like. That’s not to say that we don’t have much to work with. Universities and museums have in their collections thousands of fossil shark scales, which are considered the most abundant of vertebrate microfossils. The most well-preserved shark fossils, however, are the teeth.

The earliest shark teeth are from early Devonian deposits, some 400 million years old, in what today is Europe. These teeth are less than an inch in length (3-4 millimeters) and belonged to an ancient shark known as Leonodus. Its double-cusped teeth suggest Leonodus may have belonged to a family of freshwater sharks known as xenacanths.

Much older shark scales have been found, though. The oldest shark-like scales date back to the late Ordovician Period, about 455 million years ago, from what is now Colorado. Such scales are different from those featured by modern sharks leading many paleontologists to dispute that these truly belonged to sharks. The oldest undisputed shark scales are about 420 million years old, from early Silurian deposits in Siberia. These diminutive survivors of prehistory have been assigned to the genus Elegestolepis, but we have no clues about what the rest of the shark might have looked like.

Sharks are sometimes called primitive but if you study them long enough you might come to see they’re very well equipped, as evidenced by 400+ million years of existence. Sharks and other elasmobranchs are very cosmopolitan, being represented by many species with different adaptations. Though many sharks like the Great White are at the top of the food chain, sharks can be found at all levels of the chain. Whether the setting is benthic, pelagic, sub-tidal, or estuarine, there is a specialized shark for that environment.

Sharks are nearly impervious to infections, cancers and circulatory diseases. They can heal and recover from severe injuries very rapidly. Some say that these features were acquired by surviving one mass extinction event after the other over the course of millions of years. Again these guys are older than freaking trees! That basically sums up how badass sharks are.

Oddly enough, despite being around for over 400 million years, sharks might have met their match: humans. Because sharks go for quality, not quantity, they have a slow rate of maturation and reproduction turn-over. But sharks are no longer apex predators in their ecosystems — humans are. Demand for shark fins is driving many species of sharks extinct, as a result. Maybe trees win the day, after all.

If you’d like to learn more and find out how you can help, visit SharkSavers.

2. Images illustrating key elements of proper sensor placement for reliable sonic tomogram study of internal decay of four individuals of living Alseis blackiana trees on Barro Colorado Island, Panama. Credit: Applications in Plant Sciences

Scientists use sound waves to ‘listen’ for decay in trees

Like all living things, trees also suffer from aging, disease, and all-around decay. Unlike most organisms, however, trees are very secretive about their health. Even to the trained eye, it can be very difficult to assess whether a tree is old or in a bad shape, as a thick bark can conceal even the most advanced decay on the inside. Luckily, there are ways to probe a tree’s health without having to physically retrieve samples or make any cuts. You only have to listen.

2. Images illustrating key elements of proper sensor placement for reliable sonic tomogram study of internal decay of four individuals of living Alseis blackiana trees on Barro Colorado Island, Panama. Credit: Applications in Plant Sciences

2. Images illustrating key elements of proper sensor placement for reliable sonic tomogram study of internal decay of four individuals of living
Alseis blackiana trees on Barro Colorado Island, Panama. Credit: Applications in Plant Sciences

One such method is called sonic tomography. It allows arborists to more accurately inspect the safety of hazardous trees and reveal the quality of wood. First, a dozen or more sensors are placed around a tree’s trunk, then sound impulses are transmitted remotely to be received by the sensors. A special software calculates the measured values to make a 3-D picture of the response because sound travels differently through parts of the tree. The longer it takes for a sound wave to travel through the trunk, the more decayed it is. Damaged areas appear in red, somewhat damaged in yellow and intact in green.

Over the years, sonic tomography has proven very useful. However, one of its limitations is that it can only accurately gauge the health of trees which have cylindrical trunks. For many intents and purposes, that’s just fine but what if you need to study trees with irregular-shaped trunk? Indeed, we can imagine such a demand given irregular-shaped tree are widely found in the tropics and a lot of researchers are interested in measuring their health. Tropical forests are home to 96% of the world’s tree diversity and about 25% of terrestrial carbon, compared to the roughly 10% of carbon held in temperate forests, says Greg Gilbert,  Professor and Chair of the Department of Environmental Studies at the University of California, Santa Cruz.

Gilbert and colleagues reported in the journal Applications in Plant Sciences how they went to Panama and examined 173 species in the rainforest. Overall, the team inspected1,800 trees with sonic tomography, despite many of these trees had an irregularly shaped trunk. Apparently, using more sensors and a better placement to account for the non-cylindrical shape of the trees does the job.

“While the effectiveness of tomography to detect wood decay has been well established for use on regularly shaped trees, the expanded use of this technology for a diversity of tropical tree species with highly irregular trunks, buttresses, prop roots, and different patterns of wood production would benefit from continued efforts at validation. This can be done by taking advantage of opportunities to scan trees that are to be felled, and following up with postcutting inspection of wood decay patterns within the trunk (Gilbert and Smiley, 2004). Additionally, minimally invasive extraction of wood cores or wood material, as we have done here, can be used to quickly evaluate patterns of wood integrity and decay associated with the patterns shown in the PiCUS 3 tomograms. As standardized approaches to tomography are used on a greater diversity of tree species under different growing conditions, the utility of tomography as a research tool will continue to grow,” the researchers concluded.

NOW READ: Do trees sleep, too? 

Scientists found that gold nanoparticles (shown in red , inset) are absorbed from the soil beneath the Eucalyptus tree and concentrated in leaves and twigs. (c) Nature Communications

Gold growing on trees offers a new prospecting tool

Scientists found that gold nanoparticles (shown in red , inset) are absorbed from the soil beneath the Eucalyptus tree and concentrated in leaves and twigs. (c) Nature Communications

Scientists found that gold nanoparticles (shown in red , inset) are absorbed from the soil beneath the Eucalyptus tree and concentrated in leaves and twigs. (c) Nature Communications

The old saying “money doesn’t grow on trees” is often recited to remind squandering youth of the value of a hard-earned buck. Things turn really funny when you hear that gold, as in the actual glittering chemical element that money is used to be based on, grows on trees. In Australia, to be more precise, geochemists at  CSIRO’s Earth Science and Resource Engineering division in Kensington found that trees that grew on gold deposits had a concentration of gold particles at the surface of their leaves 40 times higher than trees that grew on normal soil.

The tree studied by the researchers led by Mel Lintern,  a geochemist with the Commonwealth Scientific and Industrial Research Organisation (Australia’s national science agency), is a certain Eucalyptus tree which grew above a known gold deposit.

The deposit is about the size of a football field and lies at least 30 meters below ground – too little for too much of an effort to be worth the exploitation. What scientists have learned after gathering twigs, bark and a myriad of trees, however, may be of greater value. Imagine prospecting operations that are both cheap and non-invasive: as easy as putting a leaf under a microscope.

gold_growing_trees

You see, after comparing the same vegetation from trees growing 200 meters away from the ore, the researchers found the ‘golden’ Eucalyptus measured 40 times more background gold concentration or 80 parts per billion (ppb).

This find came from a site in Western Australia, so the researchers wanted to see if similar results can be discovered in other areas. In Southern Australia, at another site, the researchers showed that  eucalyptus trees growing above a deposit lying 35 meters underground had 20 times more gold in the gummy substances coating their leaves than did trees that grew 800 meters away.

Their data suggested that the trees, which have roots extending up to 40m below ground, had absorbed particles of gold while searching for water during droughts, and transported to their leaves, twigs and bark.

Scientists have known for some time that trees gather tiny gold particles at the surface of their leaves, but the only viable explanation they could find at the time is that these were collected by the leaves from winds carrying and sweeping gold particles found at the surface.

To verify the gold is actually expelled from the soil underneath the trees and not simply gathered from the surface, Lintern and colleagues devised an experimental set-up.

They grew seedlings in greenhouses insulated from airborne dust and watered them with a gold-laced solution. In time, they found the gold accumulated at the surface of the leaves, proving the element was actually absorbed from the soil and expelled later.

Indeed, being a heavy metal, gold may be harmful to trees and the build-up of gold at the leaves’ surface may be the result of a defense mechanism.

“The new research provides “a conclusive set of evidence … from a very nicely constructed set of experiments,” says Clifford Stanley, a geochemist at Acadia University in Wolfville, Canada.

I know what you’re thinking. What if we mine trees? Well, you’d have your work cut out for you. The highest concentration of gold is found in the leaves. If you dry them up, you end up with an even higher concentration. Even so, the largest gold particle the scientists could find was 8 micrometers across or half the width of a human hair. Too thin and too spaced apart. Collecting gold from trees would be too much of a hassle to make anyone bother. But where the gold in  trees fails as an ore mine, it shines in its prospecting value.

Engineers could use this information to first measure gold concentration in trees from areas suspected of harboring gold deposits, and only after they find hints would the big guns be called for: geology and geophysics.

Phytomining: Scientists find gold growing on trees.

The underlying regolith stratigraphy and Au deposit is shown. (c) Nature Communications

Worldwide, new discoveries of the metal are down 45% over the past decade. All the good and easy to find spots are already taken, the next generation of prospecting will require new and ingenious methods to stay on top. Gold growing in trees might find a great part to play.

It’s worth noting that trees aren’t the only unconventional gold prospecting tool. For instance, entomologists at the same CSIRO in Australia found that termites “mine” and stockpile the precious metal while they’re collecting subterranean material for their nests. From the ZME Science article we wrote a while ago:

For the study, entomologist Aaron Stewart, with Australia’s Commonwealth Scientific and Industrial Research Organisation, and colleagues analyzed samples from several termites nests and compared them to soil samples taken from different depths.

Then, by using a mass spectrometer, they found a direct correlation between the amount of gold in the termite nest sample and their proximity to the gold source: the ones closer to the deposit had higher concentrations. A mass spectrometer analyzes the chemical make-up of the sample, by measuring the the mass-to-charge ratio of charged particles.

Also, plants have been used before to find gold – a prospecting technique called gold phytomining (when animals are used to mine it, it’s called biomining).

Using  certain hyperaccumulators – plants that have the natural ability to take up through their roots and concentrate metals such as nickel, cadmium, and zinc in their leaves and shoots  – scientists found that under certain chemical conditions, gold solubility can be forced. Some have proposed using phytomining to extract gold, essentially growing gold but it’s been found to be unfeasible. This latest research, however, is the first to show gold grows on trees.

The natural gold particles growing in Eucalyptus trees finding was reported in a paper published in the journal Nature Communications.

Editorial note: The metaphor “gold grows on trees” shouldn’t be taken literally. Gold particles are absorbed from the soil beneath the tree and then expelled at the surface of vegetation. 

“Extinct” elms discovered doing just fine in the Queen’s gardens, Edinburgh

Two elms of a species presumed to be extinct in Great Britain have been discovered in the Queen’s Edinburgh gardens in Scotland.

Image credits Lubomir Mihalik / Pixabay.

In the 1970s, Britain was being ravaged by the Dutch elm disease — an epidemic which claimed between 25 to 75 million trees. Yes, tree epidemics are a thing, and they’re really bad news for us and the species that rely on those trees for food and board. Ulmus Wentworthii Pendula, or the Wentworth elm, was tragically wiped out of the island nation by the affliction.

Or, so we thought. Two Wentworth elms were (unknowingly) found (several thousand times) hiding in plain sight in Edinburgh, adorning the Queen’s gardens. While it took a botanical survey of the grounds surrounding the Palace of Holyroodhouse, the royal residence in Scotland, to identify their species, the trees are by no means inconspicuous. Standing some 30 meters (100 feet) tall, the elms are one of the most photographed trees in the gardens — it’s just that no one ever noticed they’re “extinct” before.

“Such a discovery when the trees in question are just shy of 100 feet [30 metres] and in plain sight does sound rather odd,” said Max Coleman from the Royal Botanic Garden Edinburgh (RBGE).

He thinks they went unnoticed for so long because Wentworth elms were never very common to begin with.

“If you pull your tree book off the shelf to try and look them up, you won’t find Wentworth elm listed in the books,” he explained for the BBC.

Wentworth elms have a distinctive “weeping” habit and glossy, almost waxy, sparsely-haired upper leaf surface.
Image credits Max Coleman / Wikimedia.

Most likely, the elms were taken from the city’s botanical gardens sometime in the last century. The RBGE records show that the trees arrived there in 1902 from Germany, but after that, they only mention one tree in the gardens which fell to the disease in 1996.

“It is very tempting to speculate that the Wentworth elms at the Palace are the two missing trees from RBGE. There is anecdotal evidence that the young trees could have come in to RBGE then been grown-on before planting-out in their final positions,” said Coleman.

“Certainly, there was a close relationship between the Palace and the Garden in the early 20th century and the head gardener at Holyrood, William Smith, had trained here. And, although we have no record here of elms going out, we know that a large number of ivy plants went from here to Holyrood to plant round the abbey ruins.”

For now, though, the origins of these two surviving Wentworth elms remains mysterious. It’s a very fortunate find, however, and experts are now considering how best to restore the species starting from these two individuals. Part of that job is to figure out what helped them survive the disease that wiped out the rest of their species.

“It is very likely the only reason these rare elms have survived is because Edinburgh City Council has been surveying and removing diseased elms since the 1980s,” Coleman added. “Without that work many more of the thousands of elms in Edinburgh would have been lost. The success of this program may be partly demonstrated in the way two rare trees have been preserved.”

Now, the elms will have to start working hard at making baby elms. Hopefully, they’ll live up to the task with as much gusto as Diego the tortoise.

Douglas fir forests are buckling under the heat, pausing their growth altogether

America’s iconic Douglas firs are feeling the heat (and drought) of shifting climate patterns all across the Western U.S., finds a new University of California study.

Tiny mushrooms growing out of a Douglas Fir cone near Mount Lewis on the MiWok Ranger District of the Stanislaus National Forest. Image credits Alice Poulson / USFS Region 5 Flickr.

Tiny mushrooms growing out of a Douglas Fir cone near Mount Lewis on the MiWok Ranger District of the Stanislaus National Forest.
Image credits Alice Poulson /
USFS Region 5 Flickr.

Nobody enjoys a good old fashioned heat-wave, especially when there’s no water to be found anywhere. You’re sluggish, sweaty, bad-tempered and all you want to do is find a cool surface and put as much of your body surface against it as you can. The Douglas fir understands you. In fact, it would probably do just the same as you would, if its roots didn’t you know, root it in place.

So when confronted with a heat wave strong enough to dry the soil and air around the trees, they do the next best thing at their disposal — they stop growing altogether. And this could have huge implications for forest carbon stocks and the global carbon cycle.

“If trees are being less productive, if they are not growing as well, they are taking in less CO2 from the atmosphere,” said Christina Restaino, a postdoctoral researcher at the University of California, Davis.

“Tree stress can lead to the point where trees die, and when we lose tree species on the landscape, there’s always the question of what is going to grow back in its place.”

For the study, Restaino and her team examined more than 2,000 tree cores from 122 locations across the Western United States. They found that rising temperatures hurt the growth cycle of the trees — because it removes water from both the soil and atmosphere, the heat causes the firs to lose water faster than they can take it in. The trees respond by closing their stomata, tiny pores which shuttle in carbon dioxide and pump out oxygen during photosynthesis.

Using climate models to gauge future conditions, the team determined that the air and soil which Douglas fir forests rely on could dry up for up to double the time we see today by 2080. This would also translate into double the effect on growth we see today, the team added. The effects were most pronounced in the Southwest, which is already experiencing higher temperatures. Douglas firs in the Pacific Northwest fared a bit better.

“This is a species that has been logged historically and still is, so it certainly is important in terms of thinking about not only how our ecosystems are responding to changes in climate, but also in changes of the economics of forest management, as well,” Restaino said.

The team spent three summers harvesting their own tree cores for the study instead of using the extensive tree core data set available from the International Tree-Ring Data Bank (ITRDB.) They also used data collected by co-author Jeremy Littell, lead research scientist with the U.S. Geological Survey at Alaska’s Climate Science Center.

This way they can get an accurate snapshot of how Douglas firs respond to climate change between 1916 to 2006 across their entire U.S. range. ITRDB cores are often taken from trees in the harshest environments so they can be easily connected to the climates of past years, but that offers a biased view of the species’ response.

“We can tell a larger story about a whole range of tree-growing environments,” she said.

The full paper, titled “Increased water deficit decreases Douglas fir growth throughout western US forests” has been published online in the journal PNAS.

Trees trade carbon through their roots, using symbiotic fungi networks

A forest’s trees capture carbon not only for themselves, but also engage in an active “trade” of sorts with their neighbors, a new study found. University of Basel botanists found that this process, conducted by symbiotic fungi in the forest’s soil, takes place even among trees of different species.

Image credits pexel user veeterzy

Plants rely on photosynthesis for energy and growth. Through this process, carbon is extracted from atmospheric CO2 and used to synthesize carbohydrates (sugars). These are then further processed into stuff that a growing plant needs, like cellulose, lignin (a polymer that gives wood its resilience,) protein and lipids. Some of the sugars get sent down to the roots and shared with the tree’s underground symbiotic fungi (known as mycorrhizal fungi) in exchange for nutrients that they extract from the soil.

It’s a very effective process, providing the plant with everything it needs without it having to move a single branch. But it all falls apart without enough carbon dioxide or light, and in a thick forest these can be hard to come by. So then, why don’t young trees just wither, choked under the canopy of much bigger, older trees? Well, the answer might lie in a type of tree socialism — and mycorrhizal fungi make it all happen.

Dr. Tamir Klein and Prof. Christian Körner of the University of Basel, working with Dr. Rolf Siegwolf of the Paul Scherrer Institute (PSI) have found that forest trees use the fungal network to trade sugars among themselves. The researchers used a construction crane and a system of fine tubes to saturate the crowns of 120 year old, 40 meter tall spruce trees in a forest near Basel with labeled CO2. The gas was processed to contain less of the heavier 13C isotope than normal air.

Image credits University of Basel

For the trees, this CO2 was just as good as the rest and they gulped it all up. But it allowed the team to track the carbon atoms through the tree using mass spectrometers. They traced the atoms on their way from crown to the roots of the spruce trees and as they entered the fungi. But then something unexpected happened: neighboring trees (even those of other species) also showed the same markers even though they had not received the labelled carbon dioxide.

If the gas would have been absorbed directly by these trees, then some of it would have been caught by the underbrush too — understory plants however remained entirely unmarked. And the differentiated carbon was only found in their roots. The only explanation for its presence is an exchange between the trees through the tiny filaments of the mycorrhizal fungi.

The team considers this natural exchange of large quantities of carbon “a big surprise,” especially as it also takes place among completely unrelated species. They estimate that in an 68 meter wide and 100 meter long area the fungal network can transport around 280 kilograms of carbon a year. That accounts for nearly half the carbon in the trees’ fine roots.

“Evidently the forest is more than the sum of its trees,” Prof. Christian Körner comments.

The full paper, titled “Belowground carbon trade among tall trees in a temperate forest” has been published online in the journal Science and can be read here.

Europe might lose its ash trees forever

Europe is likely to lose all its ash trees, the largest-ever survey of the species warns. Plagued by both a fungal disease known as ash-dieback and an invasive species of beetle, the emerald ash borer, the tree might be wiped clean off of the continent.

Image credits Jørgen Larsen

Trees have been a symbol for stability, endurance and stoicism in various arts for a long, long time now. So it’s almost hard to imagine that trees, just like other organisms, can be decimated by outbreaks of disease; but it does happen.

“Between the fungal disease ash dieback and a bright green beetle called the emerald ash borer, it is likely that almost all ash trees in Europe will be wiped out – just as the elm was largely eliminated by Dutch elm disease”.

In the 1970s, Europe’s almost 15 million elm trees became afflicted with the Dutch elm disease and were largely wiped out. Now, under pressure from both a highly aggressive species of invasive beetle and a fungal disease, the continent’s ash trees are facing their own extinction scenario. This is the most common hedgerow tree in the UK, with an estimated 60,000 miles of tree lines. It is the second most common tree in the country’s woodlands after oak, and there are countless ash trees planted in towns and cities.

“Between ash dieback and the emerald ash borer, it is likely that almost all ash trees in Europe will be wiped out, just as the elm was largely eliminated by Dutch elm disease,” said Peter Thomas, tree ecologist at Keele University, UK, and author of the study.

“The two together are a double whammy.”

I don’t even know what a double whammy is but it sounds terrifying. Thomas said that the arrival of the emerald ash borer in the UK is inevitable. This bright green beetle, native to Asia, feeds on ash trees and cause little damage to the plants. The real problem are the larvae which bore under the bark and into the wood, killing the tree.

Close-up of an emerald ash borer beetle.
Image credits USGS Bee Inventory and Monitoring Lab/ flikr

“It is quite a big beetle, originally from Asia, and can fly a long way. In the past, insect diseases have spread very quickly,” Thomas said.

Attempts to halt the beetle’s spread in North America, by baiting male beetles in traps with female pheromones for example, have failed.

“It is only a matter of time before it spreads across the rest of the Europe – including Britain. Our European ash is very susceptible to the beetle and the beetle is set to become the biggest threat faced by ash in Europe – potentially far more serious than ash dieback.”

Ash dieback was first seen in Eastern Europe in 1992, but has since spread over more than 2 million sq km, from Scandinavia to Italy. The first observed case in the UK was reported in 2012 — but, given the large number of areas in which it has been found, it must have arrived earlier. It’s currently spread from Norfolk and Suffolk to South Wales. Also known as Chalara, the disease is caused by the fungus Hymenoscyphus fraxineus and kills the leaves, then the branches, trunk and eventually the whole tree. It takes a few years for a full-grown tree to succumb to the disease, but a worse-case scenario (such as what happened in Denmark) could see 95% of ash trees lost to the fungus.

Image credits BSBI/ Forestry Commission

“We already have lots that are mortally wounded,” Thomas said.

Ash dieback will be virtually impossible to eradicate from the UK as its spores can be carried for more than 10 miles by wind and survive on woodland floors for four or five years.

But there is some hope. Ash trees are pretty genetically diverse, and some of them have developed a resistance to the fungus. Three genetic markers have been identified that encode this natural resistance, and future planting efforts will use trees selected for these markers. They could also be grafted into trees via genetic engineering.

“Natural tolerance to the disease exists and the UK is leading the way on work to identify resistant strains, investing more than £21m in tree health research. Our approach also includes protecting non-infected areas and managing infected trees,” a DEFRA spokeswoman said.

Defra (Department of Environment, Food and Rural Affairs) has the emerald ash borer listed as a “significant threat” and is working with other EU nations to contain its spread, such as suspending ash tree imports since ash dieback was first identified in the UK.

“If the ash went, the British countryside would never look the same again,” Thomas said.

But this still leaves the plants defenseless against the ash borer. Beyond the loss of the trees themselves, the species is associated with over 1,000 species of animals, birds and plants. In particular, over a 100 species of lichens, fungi and insects would decline or become extinct if the ash was gone. While it may well be too late to save most ash trees, more could have been done sooner.

“It beggars belief that we had known this disease was coming for decades but we didn’t do anything about it,” Thomas concludes.

The full paper, titled “Biological Flora of the British Isles: Fraxinus excelsior” has been published online in the Journal of Ecology and is available here.

 

twisted trees slope point

Surreal crooked trees shaped by Antarctic winds

twisted trees slope point

Photo: Flickr

Slope Point is the southernmost point of New Zealand’s South Island. It lies only 4800 km (2982 mi) from the South Pole and weather can be terribly cruel. Air streams that flow over the Southern Ocean produce some of the most tear shedding winds you’ll ever see on a regular basis. It’s no wonder then that Slope Point is virtually uninhabitable, apart from sheep and a couple of farmers who tend after them. Winds are so unforgiving that the trees themselves molded into weird and crooked shapes. There’s an almost surreal beauty to their shape though, highlighting the beautiful harshness of life. You won’t find anything like it anywhere else in the world.

slope point

Image: Flickr

slope point

Image: Flickr

slope point

Image: Flickr

slope point

Image: Flickr

slope point

Image: Flickr

slope point

Image: Flickr

slope island

Image: Flickr

Broken trees in the aftermath of a hurricane storming under Sankt Petersburg, Russia

Oddly enough, all trees regardless of size break at the same wind speed

In the wake of calamities like hurricanes or tornadoes, you’ll find trees leveled to the ground. When Hurricane Sandy hit the East coast in 2012, it made a hell of a lot of trouble causing trees to topple or brake, killing or injuring people and animals, crashing into homes and cars, blocking roads and ripping down power lines. In New York City alone,  8,497 trees  fell in the hurricane’s onslaught.  In the face of such powerful forces of nature, seeing scores of broken trees isn’t odd in itself. What’s striking though is that even during less severe wind gusts, many noticed that trees are brought down regardless of their size, shape, diameter or species. Data collected from storms suggests the  critical wind speed at which trees break is constant — about 42 meters per second. Spurred by this oddity, French researchers modeled trees at the mercy of a storm too find out why exactly this happens.

forest damage after a hurricane

 

 

Various wooden rods were tested and weights were applied to record the force required to break the rods. For a fixed length, the diameter made the rods stronger as expected. But trees grow in diameter proportionally with height, in most cases. Using Hooke’s law, Griffith’s criterion, and tree allometry (the relationship of tree size parameter like diameter and height — the feedback loops), the researchers came up with a mathematical equation that explained why almost all trees seem to break at the same wind speed.

Changing parameters like its height, diameter or species did little to affect the outcome. If you double the size of a tree, the required wind speed increases by 9%. Some species are more resilient and can withstand bending stress better. Oak, for instance, breaks at a speed 10% higher than pine. Overall, though, the outcome doesn’t change significantly and at 50 m/s absolutely all trees should break.

The researchers note that this is likely an optimization nature evolved to save resources given winds so powerful (enough to turn any object into a projectile!) are rare. The same mathematical relationship might explain how coral and sedimentary organisms grow in water currents, according to David Schultz who writes for Science.

 

Dutch collective plans to “plant” a forest on Rotterdam’s waters.

If there’s one thing we all want more of in our cities it’s plants; soft grass, pretty flowers and shade-providing trees all make for comfy places to relax, clean the air and are just awesome. But where do we find the space for trees in our cities with all the buildings already vying for the limited space available?

Dutch collective Mothership’s answer is waterways. The group plans to install the “Dobberend Bos” (Bobbing Forest) in Rotterdam’s Rijnhaven harbor next spring. The forest will consist of 20 trees firmly planted inside of colorfully re-purposed buoys.

Concept of the floating forest to be installed in Rotterdam
Image via inhabitat

The group was insired by Colombian artist Jorge Bakker’s “In Search of Habitus,” an aquarium filled with teeny-tiny model buoys and trees. Bakker is known for his sculptures and installations that put often-overlooked elements of our cities, such as water and wind, into the foreground.

Bakker’s “In Search of Habitus,” the piece that served as inspiration for the Forest.
Image via inhabitat

After years of toying with the idea and experimenting with prototypes, the Motership designed a small floating forest that they’ll install in Rotterdam’s historic Rijnhaven. The harbor will host model projects in floating architecture until 2018.

“These miniature trees floating on the water raise questions about the relationship between the city dweller and nature,” according to a statement on the Dobberend Bos website.
Image via inhabitat

The city’s tree bank will provide the plants, and the 20 required buoys will be repainted and adapted by Mothership members. The harbor’s brackish waters won’t be allowed to reach the trees, Dobberend Bos website reads.

“These miniature trees floating on the water raise questions about the relationship between the city dweller and nature,” the website goes on to state.

“What does a city dweller have with nature and how humans and nature relate to the world around them?”

The project is scheduled for implementation on March 16, 2016.

Crown Shyness – Trees can shy away too!

Crown shyness is a phenomenon observed in some tree species, in which the crowns of fully stocked trees do not touch each other, forming a canopy with channel-like gaps.

Dryobalanops_Aromatica_canopyWhy?

Well, scientists are not certain what causes these remarkable patterns. But some theories have been proposed since the 1900’s to explain the phenomenon.

3 - dGUWBQi

Photo Credit

Since most of the trees are tall, slender and typically found in high wind areas, crown shyness is thought to prevent them from bumping into one another and abrading each other. The leading shoots get dispatched as an aftermath of the abrasion.

This was proven experimentally too. Scientists artificially prevented the trees from colliding in the wind and found out that they inturn fill the canopy gaps!

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Photo Credit

But studies done on the Camphor tree found no evidence of abrasions. Instead, it was suggested that the leading tips were sensitive to light. Ergo, fewer buds developed in regions that were already dense or where the crowns of different trees met. This curbed the development of shoots in regions that already were populous.

Species

Where would you find these species? Well, Crown shyness is not an exclusive phenomenon that occurs only in a country/region, it’s universal and  has been reported in various parts around the world.

Species of Dryobalanops( including Dryobalanops lanceolata and Dryobalanops aromatica ), eucalypt, Pinus contorta or lodgepole pine, Avicennia germinans or black mangrove, Didymopanax pittieri, Clusia alata,  Celtis spinosa and Pterocymbium beccarii are some well-known ones that exhibit Crown Shyness.

 

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Photo Credit

With over 100 years of research into this phenomenon, we are yet to truely uncover the mechanism of Crown Shyness. Although it is not for the lack of trying, we seem to be missing a conjoining piece that connects all the pieces together.

Look deep into Nature, and you will understand everything

As we further our understanding about the world that we dwell in, we will hopefully be able to unravel the mysteries that underly baffling phenomena of nature such as Crown Shyness and appreciate nature better.

 

 

EX-NASA Engineer Wants to Plant one Billion Trees a Year Using Drones

Each year, we cut down 26 billion trees, for lumber, agriculture, mining and development projects. Every year, we plant about 15 billion trees, so that still leaves us with a huge deficit – something which is not sustainable and has to be addressed as soon as possible to avoid further problems down the road. Now, a former NASA engineer has found that drones could play a key part, and he plans to plant up to 1 billion trees a year using them.

Drones often get a bad rep, and for good reasons; the military has been using them for years, sowing fear and panic in many areas of the world. Now, scientists and engineers want to explore other, beneficial uses for drones – sowing a better future.

The problem is that hand planting takes a lot of time, effort, and money. You need lots of people doing lots of stuff, basically – and it’s not every effective. Enter the stage Oxford-based BioCarbon Engineering; they want to redesign the way trees are planted on an industrial scale, and while 1 billion trees a year won’t eliminate damage of deforestation, it’s a hell of a start!

The thing is, drones won’t just fly at a low height and drop seeds – that’s just not going to cut it. The drones are equipped with pressurized air canisters that force the seeds into the soil, so you need a special type of drone, able to carry all this equipment, weighing 8 kg (17.5 pounds). Each pod is encapsulated in a “nutrient-rich hydrogel” that presumably feeds the seed until it takes root. Later, the drones can be used to monitor the progress of the fresh growth.

BioCarbon founder Lauren Fletcher, a former NASA engineer, says that their system can not only plant ten seeds per minute, but is also cheaper than existing alternatives.

“First, by planting germinated seeds using precision agricultural techniques, we increase uptake rates. Second, our scalable automated technology significantly reduces the manpower requirements and costs.”

Trials will take place by the end of the year, and hopefully, the technology will be successful in the near future.

“The only option we’ve had previously has been hand planting, which is slow and really expensive, and just can’t keep up with industrial-scale deforestation,” says Fletcher. “We’re hoping that our technology is going to provide opportunities to really scale up the reforestation and replanting rates.”

large tree

California lost half its large trees since 1930, steep decline continues

California’s large trees or those larger than two feet in diameter have declined in numbers to half those recorded in a 1930 census, according to a study published in  Proceedings of the National Academy of Sciences. The leading cause of the demise is thought to be rising surface temperatures which but high stress on large trees, along with water shortages. Pines are particularly vulnerable, while oaks seem to flourish and gain terrain. It seems like the state’s wetlands and forests will be dominated by bushy vegetation and densely packed small trees, as large trees will find it ever harder to survive a warming climate.

The giants are dying

large tree

California has 50% less big trees than it had in 1930. Image: Big World Trees

According to Patrick McIntyre, an ecologist at the state Department of Fish and Wildlife who was the lead author of the study, there are many factors that have contributed to this disheartening situation. Big trees are particularly susceptible to logging being easier to cut down and transport, thus being the cheapest to exploit weight per weight. Real estate has long expanded into the woods, while over zealous fire suppression has seen small trees crowd Californian forests competing for resources with the larger ones. Yet the trees’ biggest enemy is climate change.

“Older, larger trees are declining because of disease, drought, logging, and other factors, but what stands out is that this decline is statewide,” explains study leader Patrick McIntyre. The manager of biodiversity data with the California Department of Fish and Wildlife continues, “Forests are becoming dominated by smaller, more densely packed trees, and oaks are becoming more dominant as pines decline.”

He goes on to say, “The current drought in California highlights our need to understand the role of water balance in these systems and how it will be affected by global temperature rise. Forests and woodlands cover a third of California, so this has important implications for our state.”

Speaking of the Californian drought which has ravaged the state for the past four years, the study’s findings didn’t even measure its results. That’s because McIntyre and colleagues made their research by comparing a census of California forests done in the 1920s and 1930s with another survey between 2001 and 2010, right before the drought began. With this in mind, the results are even more discouraging since presently the reality must be worse.

Indeed, lack of water seems to be the prime driver for California’s big tree decline. Computer models were used to calculate how much water big trees needed versus how much they were actually getting, considering precipitation, air temperature, soil moisture, and the timing of snowmelt. Those areas where the biggest tree loss were reported coincided with those with the greatest water deficit.

Because of rising surface temperatures, trees lose more water to the atmosphere, while early snowmelt reduces the water available during the dry season. Of course, the water shortage affects all trees, but large trees even more so. Because they’re taller, the internal hydraulic system that pumps water and nutrients up through the tree is more susceptible to failure when out of enough water. There’s also a hypothesis that given the most large trees sprouted centuries ago during a colder climate, it’s possible that they find it harder to adapt.

Throughout the state, the most severe declines were among pine trees, including ponderosa, sugar, and Jeffrey pines. Their place has been taken by trees smaller than a foot across, which have surged across the state.  Oaks are an increasing presence in the Sierras and along the north coast, while declining slightly in southern California.

While large trees are indeed being replaced, their rapid downfall as well as their unique ecological role still makes this sound like a disaster. Large trees store more carbon that their smaller shrubby  brethren, and provide homes for animals like spotted owls and flying squirrels.

Hyperion located in Redwoods, California, is the tallest tree in the world measuring 115.61 meters high and 4.84 meters in diameter. It’s between 700 and 800 years old and belongs to the Sequoia sempervirens species. As an interesting fact all of the top ten tallest trees in the world are in California, and four out of the top five trees are in Redwoods. The study doesn’t say anything about sequoias and redwoods, California’s trademark giants.

Professor Bekker and a student extract a core sample from a dead tree in Provo canyon

Tree rings reveal worst droughts in the West’s history happened during Christopher Columbus’ lifetime

Professor Bekker and a student extract a core sample from a dead tree in Provo canyon

Professor Bekker and a student extract a core sample from a dead tree in Provo canyon. (C) BYU

Modern climate tracking and water flow records go back only 100 years, but to prepare for the worse, scientists and policy makers alike need to understand how the weather was like in the world many more years prior. A solution is to study the tree rings of certain tree species which bear telltale signs of water levels hundreds of years past, as  Brigham Young University professor Matthew Bekker suggests.

Bekker analyzed rings from drought-sensitive tree species and remarkably found that  the worst drought of this century barely makes the top 10 of a study that extended Utah’s climate record back to the year 1429. Here are some conclusions Bekker could gather simply by closely following tree rings, whose thickness is directly dependent on water intake at the time, using only simple tools like sandpaper and a microscope:

– Long droughts: The year 1703 kicked off 16 years in a row with below average stream flow.

– Intense droughts: The Weber River flowed at just 13 percent of normal in 1580 and dropped below 20 percent in three other periods.

– Consecutive worst-case scenarios: The most severe drought in the record began in 1492, and four of the five worst droughts all happened during Christopher Columbus’ lifetime.

“We’re conservatively estimating the severity of these droughts that hit before the modern record, and we still see some that are kind of scary if they were to happen again,” said Bekker, a geography professor at BYU. “We would really have to change the way we do things here.”

research_tree_ring

(C) BYU

This analysis which goes back more than 500 years tells us that the West was once subjected to drought fluctuations much more severe than anything we’ve seen in recent history. If this happened before, then it can certainly happen in the future. The real questions that remain to be answered is when these periods of severe drought might come again in the future, and what signs can scientists look for to forecast their coming.

“We’re trying to work with water managers to show the different flavors of droughts this region has had,” said Bekker. “These are scenarios you need to build into your models to know how to plan for the future.”

The findings were reported in the Journal of the American Water Resources Association.