Unique Chameleon Woody Vine Discovered in Chile!!!

Move over, Sherlock Holmes. There is a new master of disguise—and it’s a plant. Camouflage and mimicry are usually reserved for the animal realm. The hawk moth caterpillar scares away predators by resembling a snake. Myrmarachne jumping spiders imitate ants as they creep up on unsuspecting insects—fangs ready. Fewer examples of mimicry—or crypsis—are known for plants. But as in some mistletoe species in Australia, all of these imposters copy only one other species. That’s not the case with the woody vine Boquila trifoliolata, which transforms its leaves to copy a variety of host trees. Native to Chile and Argentina, B. trifoliolata is the first plant shown to imitate several hosts. It is a rare quality—known as a mimetic polymorphism—that was previously observed only in butterflies, according to this study, published today in Current Biology. When the vine climbs onto a tree’s branches, its versatile leaves (inset) can change their size, shape, color, orientation, and even the vein patterns to match the surrounding foliage (middle panel; the red arrow points to the vine, while the blue arrow indicates the host plant). If the vine crosses over to a second tree, it changes, even if the new host leaves are 10 times bigger with a contrasting shape (right panel). The deceit serves as a defense against plant-eating herbivores like weevils and leaf beetles, according the researchers. They compared the charlatan leaves hanging on branches with the leaves on vines still crawling on the forest floor in search of a tree or scaling leafless trunks. Herbivory was 33% and 100% worse for the vines on the ground and on tree trunks, respectively. It is unclear how B. trifoliolata vines discern the identity of individual trees and shape-shift accordingly. The vines could read cues hidden in odors, or chemicals secreted by trees or microbes may transport gene-activating signals between the fraud and the host, the researchers say.

Source: Science Magazine

Paper or Plastic?

As a landscape architect, I am always thinking about how the natural world can play a larger role in our urban environments. Obviously trees and parks are the primary methods that come to mind.  But I recently came across an article in Architect Magazine that examined the role cellulose could potentially play in our urban environments...that is, in the role we currently see played by conventional plastics.

Conventional plastics are inexpensive and can be found everywhere.  Site furniture, play structures, and decking are just a few of the items I immediately think about with practical use in landscape architecture.  If these items were replaced with an 'environmentally persistent compound' that provided ecological benefit, there could be vast improvements concerning the vitality of our urban environments.

This new product, created by Zeoform, is made of nothing more than recycled paper waste and water. Zeoform mimics the characteristics of plastic and wood and can be molded, routed, sanded, engraved, and laser-cut into about any shape you could imagine.


Image courtesy of Zeoform.

There are a few questions I have been thinking about.  With this material being biodegradable and made of cellulose and water, is there a high potential for the material to loose its structural qualities and acquire mold? The product is "a combination of fiber entanglement and hydroxyl bonding" but how will this hold up to the everyday wear and tear in the urban environment?

I am excited to see how this product will play out.  Like Ecovative Design's Mushroom Materials (see past blog post), These are the types of innovations we like to see here at The Sharp End of the Green Stick!

Rate of Tree Carbon Accumulation Increases Continuously with Tree Size

Forests are major components of the global carbon cycle, providing substantial feedback to atmospheric greenhouse gas concentrations1. Our ability to understand and predict changes in the forest carbon cycle—particularly net primary productivity and carbon storage—increasingly relies on models that represent biological processes across several scales of biological organization, from tree leaves to forest stands. Yet, despite advances in our understanding of productivity at the scales of leaves and stands, no consensus exists about the nature of productivity at the scale of the individual tree, in part because we lack a broad empirical assessment of whether rates of absolute tree mass growth (and thus carbon accumulation) decrease, remain constant, or increase as trees increase in size and age.

A global analysis of 403 tropical and temperate tree species, shows that for most species mass growth rate increases continuously with tree size. Thus, large, old trees do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees; at the extreme, a single big tree can add the same amount of carbon to the forest within a year as is contained in an entire mid-sized tree. The apparent paradoxes of individual tree growth increasing with tree size despite declining leaf-level and stand-leve productivity can be explained, respectively, by increases in a tree’s total leaf area that outpace declines in productivity per unit of leaf area and, among other factors, age-related reductions in population density.

Results resolve conflicting assumptions about the nature of tree growth, inform efforts to undertand and model forest carbon dynamics, and have additional implications for theories of resource allocation and plant senescence.

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12914.html

Filtering dirty water with plant xylem!

Tree pores (red and blue) located within the sapwood filter bacteria (green) in dirty water.photo credit: Boutilier et al.

To turn dirty lakewater into drinkable H2O, peel away the bark from a nearby tree branch and slowly pour water through the wood. According to new research, this neat, low-tech trick ought to trap any bacteria, leaving you with uncontaminated water. 

 

Okay, time for a little tree physiology. To get water and minerals up a tree, wood is comprised of xylem, porous tissue arranged in tubes for conducing sap from the roots upwards through a system of vessels and pores. Xylem tissue is found in sapwood, the younger wood that lies in concentric circles between the central heartwood and the bark. Tiny pores called pit membranes are scattered throughout the walls of the vessels, allowing sap to flow from one vessel to another, feeding various structures along a tree’s length. 

 

Turns out, the same tissue that evolved to transport sap up the length of a tree also has exactly the right-sized pores to allow water through while blocking bacteria. Additionally, the pores also trap air bubbles, which could kill a tree if spread in the xylem. “Plants have had to figure out how to filter out bubbles but allow easy flow of sap,” study author Rohit Karnik from MIT says in a news release. “It’s the same problem with water filtration where we want to filter out microbes but maintain a high flow rate. So it’s a nice coincidence that the problems are similar.” 

 

As Karnik’s team finds, a small piece of sapwood can filter out more than 99 percent of the E. coli from water, at the rate of several liters per day.

 

To study sapwood’s water-filtering potential, the team collected white pine branches and stripped off their outer bark. They attached inch-long sections of sapwood to plastic tubing, then sealed it with epoxy and secured it with clamps.

They tested their improvised filter using water mixed with particles ranging in size. They found that while sapwood naturally filters out particles bigger than 70 nanometers, it wasn’t able to separate out 20-nanometer particles. 

 

When they poured water contaminated with inactivated E. coli through the sapwood filter, they saw how bacteria had accumulated around the pores in the first few millimeters of the wood. In the false-color electron microscope image above, (green) bacteria are trapped over pit membranes (red and blue). 

 

Existing water-purification technologies that use chlorine treatments and membranes with nano-scale pores are expensive. Even boiling water requires fuel for heat. Here, just take some wood and make a filter of it -- it’s low-cost, efficient, and readily accessible for rural communities as well as dehydrated campers in the Northeast. “Ideally, a filter would be a thin slice of wood you could use for a few days, then throw it away and replace at almost no cost,” Karnik explains. 

 

The group is looking into the filtering potential of other types of sapwood. Flowering trees, for example, tend to have smaller pores than coniferous trees and may be able to filter out even smaller particles, like viruses. 

The question now is how does this science become a game changer for underdeveloped nations who need it the most?  What materials will the most effective filter need and are there specific species of trees that will filter more effectively. Future studies will only empower nature-loving enthusiasts. Until then, let's plant some trees!

 

The work was published in PLOS ONE last week. 

Watch 63 Years of Climate Change in one Horrifying GIF

Global warming is still the topic of much debate, but a short video posted recently by NASA is fairly convincing. The 15-second animation, which was posted by NASA last week and picked up on Tuesday by Co.Exist, shows a view of the entire globe with an overlay that details climate change. NASA scientists analyzed data collected over the past 63 years by 1,000 meteorological stations from around the world, and the animation they compiled shows just how rapidly the Earth’s climate is changing.

The GIF is a consolidated version of NASA’s full animation that helps illustrate just how drastic the change has been since 1950. Temperatures in some regions have swung by as much as 4 degrees Celsius in the past 60 years alone.

“Long-term trends in surface temperatures are unusual and 2013 adds to the evidence for ongoing climate change,” GISS climatologist Gavin Schmidt said with regard to NASA’s findings. “While one year or one season can be affected by random weather events, this analysis shows the necessity for continued, long-term monitoring.”

According to the report, the average global temperature in 2013 was 58.3 degrees; Fahrenheit. That’s 1.1 degrees Fahrenheit warmer than the mid-20th century baseline temperature.

“Last year, when the concentration of carbon dioxide in the atmosphere surpassed levels of 400 parts per million, the amount of atmospheric carbon dioxide reached a higher point than it had at any time in the last 800,000 years,” Sydney Brownstone noted.

NASA’s full animation follows below.



http://bgr.com/2014/01/29/global-warming-gif-video/

Robotic Construction Crew Needs No Foreman

The TERMES robots can carry bricks, build staircases, and climb them to add bricks to a structure, following low-level rules to independently complete a construction project.

Credit: Eliza Grinnell, Harvard SEAS

On the plains of Namibia, millions of tiny termites are building a mound of soil -- an 8-foot-tall "lung" for their underground nest. During a year of construction, many termites will live and die, wind and rain will erode the structure, and yet the colony's life-sustaining project will continue.

Inspired by the termites' resilience and collective intelligence, a team of computer scientists and engineers at the Harvard School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering at Harvard University has created an autonomous robotic construction crew. The system needs no supervisor, no eye in the sky, and no communication: just simple robots -- any number of robots -- that cooperate by modifying their environment.

Harvard's TERMES system demonstrates that collective systems of robots can build complex, three-dimensional structures without the need for any central command or prescribed roles. The results of the four-year project were presented this week at the AAAS 2014 Annual Meeting and published in the February 14 issue of Science.

The TERMES robots can build towers, castles, and pyramids out of foam bricks, autonomously building themselves staircases to reach the higher levels and adding bricks wherever they are needed. In the future, similar robots could lay sandbags in advance of a flood, or perform simple construction tasks on Mars.

"The key inspiration we took from termites is the idea that you can do something really complicated as a group, without a supervisor, and secondly that you can do it without everybody discussing explicitly what's going on, but just by modifying the environment," says principal investigator Radhika Nagpal, Fred Kavli Professor of Computer Science at Harvard SEAS. She is also a core faculty member at the Wyss Institute, where she co-leads the Bioinspired Robotics platform.

Most human construction projects today are performed by trained workers in a hierarchical organization, explains lead author Justin Werfel, a staff scientist in bioinspired robotics at the Wyss Institute and a former SEAS postdoctoral fellow.

"Normally, at the beginning, you have a blueprint and a detailed plan of how to execute it, and the foreman goes out and directs his crew, supervising them as they do it," he says. "In insect colonies, it's not as if the queen is giving them all individual instructions. Each termite doesn't know what the others are doing or what the current overall state of the mound is."

Instead, termites rely on a concept known as stigmergy, a kind of implicit communication: they observe each others' changes to the environment and act accordingly. That is what Nagpal's team has designed the robots to do, with impressive results. Supplementary videos published with the Science paper show the robots cooperating to build several kinds of structures and even recovering from unexpected changes to the structures during construction.

Each robot executes its building process in parallel with others, but without knowing who else is working at the same time. If one robot breaks, or has to leave, it does not affect the others. This also means that the same instructions can be executed by five robots or five hundred. The TERMES system is an important proof of concept for scalable, distributed artificial intelligence.

Nagpal's Self-Organizing Systems Research Group specializes in distributed algorithms that allow very large groups of robots to act as a colony. Close connections between Harvard's computer scientists, electrical engineers, and biologists are key to her team's success. They created a swarm of friendly Kilobots a few years ago and are contributing artificial intelligence expertise to the ongoing RoboBees project, in collaboration with Harvard faculty members Robert J. Wood and Gu-Yeon Wei.

"When many agents get together -- whether they're termites, bees, or robots -- often some interesting, higher-level behavior emerges that you wouldn't predict from looking at the components by themselves," says Werfel. "Broadly speaking, we're interested in connecting what happens at the low level, with individual agent rules, to these emergent outcomes."

Coauthor Kirstin Petersen, a graduate student at Harvard SEAS with a fellowship from the Wyss Institute, spearheaded the design and construction of the TERMES robots and bricks. These robots can perform all the necessary tasks -- carrying blocks, climbing the structure, attaching the blocks, and so on -- with only four simple types of sensors and three actuators.

"We co-designed robots and bricks in an effort to make the system as minimalist and reliable as possible," Petersen says. "Not only does this help to make the system more robust; it also greatly simplifies the amount of computing required of the onboard processor. The idea is not just to reduce the number of small-scale errors, but more so to detect and correct them before they propagate into errors that can be fatal to the entire system."

In contrast to the TERMES system, it is currently more common for robotic systems to depend on a central controller. These systems typically rely on an "eye in the sky" that can see the whole process or on all of the robots being able to talk to each other frequently. These approaches can improve group efficiency and help the system recover from problems quickly, but as the numbers of robots and the size of their territory increase, these systems become harder to operate. In dangerous or remote environments, a central controller presents a single failure point that could bring down the whole system.

"It may be that in the end you want something in between the centralized and the decentralized system -- but we've proven the extreme end of the scale: that it could be just like the termites," says Nagpal. "And from the termites' point of view, it's working out great."

This research was supported by the Wyss Institute for Biologically Inspired Engineering at Harvard University.

What can a TERMES robot do?

- Move forward, backward, and turn in place
- Climb up or down a step the height of one brick
- Pick up a brick, carry it, and deposit it directly in front of itself
- Detect other bricks and robots in immediate vicinity
- Keep track of its own location with respect to a "seed" brick

What instructions do the TERMES robots follow?

- Obey predetermined traffic rules
- Circle the growing structure to find the first, "seed" brick (for orientation)
- Climb onto the structure
- Obtain a brick
- Attach the brick at any vacant point that satisfies local geometric requirements
- Climb off the structure
- Repeat

http://www.sciencedaily.com/releases/2014/02/140213142134.htm

JBC NOAA Green Roof Profiled

The NOAA Southwest Fisheries Green Roof in La Jolla, California designed by Jeffrey L. Bruce & Company is profiled on "A Growing Passion" hosted by Nan Sterman