Some trees may ‘social distance’ to avoid disease

api.nationalgeographic.com

By Katherine J. Wu

PUBLISHED July 6, 2020

On a warm day in March 1982, biologist Francis “Jack” Putz strayed into a knot of black mangrove trees seeking relief from the afternoon heat. Drowsy from his midday meal and hours of fieldwork in Costa Rica’s Guanacaste National Park, Putz decided to lie down for a short siesta.

As he gazed skyward, the wind stirred the tops of the mangroves above him, causing the limbs of neighboring trees to claw at each other and snap off some of their outermost leaves and branches. Putz noticed that this reciprocal pruning had left tracks of empty space running through the canopy.

This network of treetop chasms, called crown shyness, has been documented in forests around the world. From the mangroves of Costa Rica to the towering Borneo camphor trees of Malaysia, gaps in the greenery abound. But scientists still don’t fully understand why the tops of trees so often refuse to touch.

Beneath the mangroves 40 years ago, teetering on the verge of a post-lunch snooze, Putz reasoned that trees need personal space, too—a critical step toward unraveling the roots of the branches’ bashful behavior.

“I often make great discoveries at naptime,” he says.

Today, a growing body of work continues to support the early observations of Putz and his colleagues. Wind, it seems, plays a crucial role in helping many trees maintain their distance. The boundaries carved by bouts between branches may improve the plants’ access to resources, such as light. Gaps in the treetops might even curb the spread of leaf-munching insects, parasitic vines, or infectious disease.

In some ways, crown shyness is the arboreal version of social distancing, says Meg Lowman, a forest canopy biologist and director of the TREE Foundation. “The minute you start keeping plants from physically touching each other, you can increase productivity,” she says. “That’s the beauty of isolation … The tree is really safeguarding its own health.”

Tussling in the treetops

Though descriptions of crown shyness have appeared in scientific literature since the 1920s, several decades passed before researchers started systematically digging into the phenomenon’s cause. Some scientists initially pursued a hypothesis that trees were simply failing to fill the spaces between their canopies due to a lack of light—a crucial resource for photosynthesis—where their foliage overlapped.

But Putz’s team published research in 1984 showing that in some cases, crown shyness may simply be the product of a battle between windblown trees, each racing to sprout new branches and parry strikes from their neighbors. In their research, the more mangroves swayed in the wind, the more widely their canopies were spaced from those of their neighbors—some of the first results supporting this so-called abrasion hypothesis to explain the treetop patterns.

About two decades later, a team led by Mark Rudnicki, a biologist at Michigan Technological University, measured the forces jostling lodgepole pine treesin Alberta, Canada. Windy forests full of tall, spindly trunks of similar height were especially prone to crown shyness, they found. And when Rudnicki and his team used nylon ropes to prevent neighboring pines from colliding, the plants interlocked their canopies, filling in the gaps between adjacent crowns.

Other scientists have found clues that several paths to crown shyness likely exist, and some are perhaps less combative than these windy tussles. For instance, Rudnicki says some trees may have learned to stop growing at their tips entirely, wising up to the fact that any new foliage will be stripped away.

Trees could thus avoid unnecessary damage, says Inés Ibáñez, a forest ecologist at the University of Michigan. “Growing new tissue is very costly for plants … It’s like the trees being preemptive: Let’s not grow here because it’s not worth it.”

Some trees may be capable of taking this prudence a step further by using a specialized sensory system to detect chemicals emanating from nearby plants. “There’s a growing body of literature around plant cognizance,” says Marlyse Duguid, a forester and horticulturist at Yale University. Data on chemical communication in woody plants is sparse, but if trees can sense each other, they may be able to halt canopy growth before they’re forced to tussle.

The perks of personal space

Regardless of how crown shyness occurs, the separation likely comes with benefits. “Leaves are like a tree’s most expensive diamonds—you want to protect them at all costs,” Lowman says. “If a whole bunch get bumped off, that’s a terrible disaster for the tree.”

Sparser foliage could also help sunlight reach forest floors, nurturing the ground-dwelling plants and animals that in turn support arboreal life. Putz thinks the gaps may even help trees avoid invasive, woody vines called lianas—which are common in tropical and temperate forests around the world—or buffer the plants against disease-causing microbes and flightless insects that use canopies as conduits. (Some germs and bugs could still theoretically make the hop when trees box in the breeze.)

Many of these possible advantages, however, have yet to be conclusively linked to crown shyness. Forest canopies—the tops of some of the world’s tallest plants—aren’t easy to study, says Lowman, a self-described “arbonaut” and one of the few scientists who has made a career studying canopies. Examining the tops of trees requires quite a bit of climbing, balance, and bravery. “The limiting factor is our inability to deal with gravity to get to those places,” she says.

Still, ignoring the canopy of a tree is like trying to understand the human body from only the waist down, Lowman says. The crowns of trees teem with life—and much of this biodiversity may still be undiscovered, especially in the tropics.

Luckily, crown shyness “isn’t something you have to get on a plane to see,” Putz says. “It’s happening all around—and what an enriching thing for people to look up and see.”

https://api.nationalgeographic.com/distribution/public/amp/science/2020/07/tree-crown-shyness-forest-canopy?__twitter_impression=true

Petition to Register “Radical Predators” in a Public Database!

change.org

Hesitant Heroes started this petition to Representative Barbara Lee and 17 others 3-4 minutes

This petition aims to help pass a bill that would create a public registry for people who have been found guilty of committing a felony racial hate crime, similar to what already exists for those convicted of sex crimes.

First and foremost, we would like to convey our deepest condolences to the families of all those who have lost their lives due to the unjust, systematically biased America in which we find ourselves; in which we have always found ourselves. George Floyd, Breonna Taylor, Rayshard Brooks, Eric Garner, Sandra Bland, Laquan McDonald, Tamir Rice, Alton Sterling, Freddie Gray, Rekia Boyd, Walter Scott and so many others. As we have witnessed the irreparable harm that has already been done, we continue to see African Americans subjected to these injustices daily. And we continue to see the perpetrators of these injustices not be held accountable. This must change.

Recently, there has been a plethora of videos to surface that shows racist people flaunting, abusing and misusing 911 as their own personal tool to fulfill their racist intentions. This crime is not only racist, it is reckless, abhorrent and could lead to death. Since the murder of Emmett Till, it has been a constant plague in our society.

Lawmakers in the city of New York have recently passed legislation that will make false race-based 911 reports a hate crime, according to Andrew Cuomo’s “Say Their Name” Reform Agenda. We vehemently support this bill, but want to push it further. We demand that those convicted be entered into a public database as Racial Predators. Eventually we hope to include all hate crimes (including, but not limited to, hate crimes based on sexual orientation/identification, creed or sex.) There is no legal accountability that is sufficient enough for the magnitude of this crime; nothing that would deter the misuse of our justice system or the continuation of these false accusations.

This petition calls to not only hold civilians accountable for race-based actions, but also for the accountability of Law Enforcement. In a Guardian article, Paul Butler states: “Cops routinely hurt and humiliate black people because that is what they are paid to do. Virtually every objective investigation of a US law enforcement agency finds that the police, as policy, treat African Americans with contempt.” These officers will search for every reason that might lead to an arrest and abusers have used this to their advantage.

The transparency of police officer’s prior disciplinary records, as well as the elimination of “Qualified Immunity” are essential in this venture. Truly reforming our broken system requires getting to the foundation of how it works. A farmer knows that nothing will grow an overgrown field by merely sprinkling seeds on top of the weeds. They need to clear the field and till the soil in order for things to grow. Let’s do what we need to do to plant the seeds that will feed and sustain our society.

We are demanding through this petition that anyone, including police officers who are convicted in this crime or any other racist hate crimes, MUST be registered as a racial predator in a public database so that we all know who they are.

Enough is enough.

https://www.change.org/p/petition-to-register-racial-predators-in-a-public-database?source_location=petition_footer&algorithm=promoted&original_footer_petition_id=18464416&grid_position=3&pt=AVBldGl0aW9uABG9VwEAAAAAXwTU2IRM3944ZjdkNWYzOQ%3D%3D

Petition · United States Supreme Court: Justice for Atlanta Officer Garrett Rolfe! · Change.org

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Bryse Sunderlin started this petition to United States Supreme Court and 5 others

Atlanta, GA – Fulton County District Attorney Paul Howard has announced seven felony charges – including murder – against former Atlanta Police Officer Garrett Rolfe who fatally shot Rayshard Brooks at Wendy’s on Friday night. The Georgia Bureau of Investigation is still investigating the shooting, but Howard was quick to file charges against Rolfe. This is a blatant disregard for due process and “innocent until proven guilty.”

This was a completely justified shooting and the officers life was on the line. Now he’s being dragged through the dirt and facing murder charges for defending himself. We need to defend his rights! #JusticeForRolfe

SHARE, SHARE, SHARE!

Updates

  1. 2 weeks ago17,500 supporters
  2. Justice For Officer Rolfe!To everyone who has signed— Thank you so much for your support. Your support for Officer Rolfe, and all police around the country. The latest update is that several Atlanta PD officers have walked out while on duty. S… Bryse Sunderlin3 weeks ago
  3. 3 weeks ago1,000 supporters
  4. 3 weeks agoBryse Sunderlin started this petition

https://www.change.org/p/united-states-supreme-court-justice-for-atlanta-officer-garrett-rolfe?source_location=petition_footer&algorithm=promoted&original_footer_petition_id=18464416&grid_position=5&pt=AVBldGl0aW9uAOGFXQEAAAAAXwTMtvrG0Qc3NWVlZDgwNA%3D%3D

Petition to Kellogg’s: Please make it vegan!

Herbivore Club started this petition to Kellogg

Whilst Kellogg’s does have a number of vegan cereals and products, they could expand this range extensively by simply switching the vitamin D used in their cereals to a plant-based version.

The vitamin D currently used in most of Kellogg’s products is an animal-derived version of vitamin D3. This comes from a substance called lanolin, which is found in sheep’s wool.

Vegans avoid wool and products made from wool for a number of reasons. Firstly, there is an inherent link between the wool industry and the meat industry. Additionally, undercover investigations into the wool industry have shown abuse and horrific treatment of gentle sheep during the sheering process.

Plant-based vitamin D can be in the form of vitamin D2 or a plant-derived D3.

Last year, Animal Aid announced that supermarket giant Asda has swapped the vitamin D in a number of their cereals to a plant-based version, making a number of their own-brand cereals vegan.

This simple swap does nothing to alter the taste or quality of the product, but it does open it up to a huge and ever-growing vegan market.

Please join us in urging Kellogg’s to swap the vitamin D3 in their cereals for a vegan version.

Updates

  1. 6 days ago5,000 supporters
  2. PBN: Kellogg’s Urged To Use Plant-Based Vitamin D In All CerealsPlantbased news has published an article about our petition: Click hereHerbivore Club7 months ago
  3. 7 months ago1,000 supporters
  4. 9 months agoHerbivore Club started this petition

https://www.change.org/p/kellogg-s-please-make-it-vegan?use_react=false

Think Your Dog is a Good Communicator? Congratulate Yourself

firepaw.org

Researchers have found that dogs adapt their communicative strategies to their environment and that owner behavior influences communicative effort and success.

Study Overview

Given the remarkable sensitivity of dogs to human vocalizations, gestures and gazes, researchers have suggested that 30.000 years of domestication and co-evolution with humans may have caused dogs to develop similar principles of communication — a theory known as the domestication hypothesis.

On this basis, researchers designed an experiment that would examine the factors influencing the form, effort and success of dog-human interactions in a hidden-object task. Using 30 dog-owner pairs, researchers focused on a communicative behavior called showing, in which dogs gather the attention of a communicative partner and direct it to an external source.

While the owner waited in another room, an experimenter in view of a participating dog hid the dogs` favorite toy in one of four boxes. When the owner entered the room, the dog had to show its owner where the toy had been hidden. If the owner successfully located the toy, the pair were allowed to play as a reward. Participants were tested in two conditions: a close setup which required more precise showing and a distant setup which allowed for showing in a general direction.

Results Overview

The findings indicate that a crucial factor influencing the effort and accuracy of dogs’ showing is the behavior of the dog’s owner. Owners who encouraged their dog to show where the toy was hidden increased their dog’s showing effort but generally decreased their showing accuracy.  Bottom line: the current study indicates for the first time that owners can influence their dog’s showing accuracy and success.


Journal Reference: Melanie Henschel, James Winters, Thomas F. Müller, Juliane Bräuer. Effect of shared information and owner behavior on showing in dogs (Canis familiaris). Animal Cognition, 2020; DOI: 10.1007/s10071-020-01409-9


https://firepaw.org/2020/07/07/think-your-dog-is-a-good-communicator-congratulate-yourself/#like-7045#like-7045