anthropogen

: of, relating to, or resulting from the influence of human beings on nature

Euphorbiaceae, Jatripha sympetala – Jalisco, Mexico

I’m pretty sure this is Jatropha sympetala. The trunk texture and bark are like a yellow version of many of the Bursera spp. in this region. Locally the tree is called “Papelillo”, which is the name ascribed to the Bursera as well. The tree grows up to 10 m high with a round(ish) branching canopy. As can be observed in the photo below, the bark peels off the trunk in large, very thin sheets. Deciduous and very drought tolerant.

For those interested, here are some previous posts from this site related to the Euphorbiaceae family.

Euphorbia tanquahuete SCW_7141 SCW_7142

Plants make their own sunscreen to block damaging rays

Here’s an interesting article from New Scientist referencing recent research published in the Journal of the American Chemical Society about how plant’s protect themselves from UV rays while sitting out in the sun all day…

They bask in the sun for hours, but just like us, plants need to protect themselves from damaging ultraviolet rays. Now we know how they do it.

Many plants use a group of chemicals called sinapate esters to defend against the sun, while they absorb light for photosynthesis. These aromatic compounds sit in the upper cell layers of these plants’ leaves and one type – sinapoyl malate – provides the bulk of this UV protection.

A team led by Timothy Zwier of Purdue University in West Lafayette, Indiana, has probed how sinapoyl malate works, finding that it filters out the entire spectrum of ultraviolet-B radiation, which is known to damage plant and human DNA.

“It can absorb all wavelengths of UV-B radiation, with no ‘gaps’ in coverage,” says Zwier.

Close to zero

Zwier and his colleagues identified the wavelengths that sinapoyl malate intercepts by cooling the substance to near absolute zero and trapping it in argon gas to stop it from evaporating before its ability to block UV-B could be measured.

Gareth Jenkins, who studies UV-B absorption by plants at the University of Glasgow, UK, says that the work shows how effective the sinapate esters are at cutting out radiation. “Plants do not usually show signs of UV damage in sunlight, so the mechanisms they’ve evolved for UV protection, which include sunscreen production, evidently work pretty well,” he says.

The range of UV wavelengths blocked by sinapoyl malate is the same as those that damage human tissues, but Zwier has no plans to develop it as a sun cream ingredient. Closely related natural substances called cinnamates are equally as effective, and are already used widely in sunblocks.

Instead, Zwier says his finding could be useful for developing plants that are even more resistant to UV radiation – something that could come in handy as heatwaves, which have more UV, become more common with climate change.

Journal reference: Journal of the American Chemical Society, DOI: 10.1021/ja5059026

Read full article at New Scientist.com

Phytomining hyperaccumulator plants – the future of metal extraction?

Here’s a recent article on the emerging field of phytomining – the exploitation of sub-economic ore bodies using plants… in other words: a method of metal extraction revolving around the mass cultivation of so-called “metal – hyperaccumulator” plants to harvest metals such as nickel, zinc and cobalt. Would-be phytominers grow a crop of a metal-hyperaccumulating plant species, harvest the biomass and burn it to produce a bio-ore.

Yes, phytomining does also have the potential secondary application to revegetate and control erosion in otherwise decimated former strip mines, where few organisms will grow, but what does the pursuit of phytomining say about the modern human’s perpetually distanced relationship with non-human species? Is phytomining just another way for people to greedily suck prized resources from the earth to turn a profit? Or is it the next eco-groovy road to El Dorado? Or both? Surely, someone out there is feverishly seeking a way to phyto-mine gold…

Inside a lab at the University of Queensland in Brisbane, Australia, soil samples sit under a row of a glowing light bulbs hanging from a track only a short distance above them. In another room, a centrifuge hums as beakers of Nyquil-colored liquids sit on a nearby shelf. Standard white lab coats hang on hooks outside.

This generic-looking lab feels worlds away from the gritty, dusty mines of Australia—but this is where scientists hope to chart a new path for the industry here, and across the world.

If work being done at the Centre for Mined Land Rehabilitation catches on, it could mean new futures for global communities affected by resource-hungry strip-mining, and new ways for the mining industry to do business.

Australian scientists hope to accomplish this with phytomining—harvesting valuable metals from plants. Essentially, it’s growing plants containing nickel, zinc and cobalt—the bread and butter of the world’s mines, and harvesting the metals above ground, not below.

“We have identified a whole lot of new species which could be used for phytomining which weren’t previously known to science,” said Dr. Peter Erskine, one of the researchers working to make the process suitable for conventional mining companies.

Click here to read the full article…

Another quick article from Science Direct…

An optimistic phytomining article from Nerdist.com

And yes, an article on phytomining gold from Science Direct, published in the Journal of Geochemical Exploration

Malvaceae / Bombacaceae, Pseudobombax ellipticum – Mexico

Pseudobombax ellipticum, known in English as Shaving Brush tree (in reference to the flower) is native to Mexico and Central America where it is referred to variously as Acoque, amapola, árbol de doncellas, árbol de señoritas, calinchuche, jilinsuche, matías, pilinsuchil, pumpo, shaving bush, shilo, shilo blanco, shilo colorado. I took these photos in Mexico where it is called Clavelina.

Mature trees grow to about 60 ft developing an engorged, bottle trunk.

Please refer to these photos of the closely related Pseudobombax septanatum, from a previous post. P. septanatum is a somewhat larger version of P. ellipticum.

Here are previous entries on other plants in the Bombacaceae family, and since they have all merged, here are Sterculiaceae, and Malvaceae as well.

I’ll get photos of the flower.

Pseudobombax ellipticum leaf Pseudobombax ellipticum trunk

Researchers find ferns communicate with one another to decide gender

(Phys.org) —A combined team of researchers from Nagoya University and the University of Tokyo has discovered that a certain type of fern plant communicates with others of its kind using pheromones as a means of choosing the gender of maturing plants. In their paper published in the journal Science, the researchers describe how their study of the Japanese climbing fern, led to a better understanding of the role that the pheromone gibberellin plays in its reproduction process. Tai-ping Sun, with Duke University offers a perspective piece in the same journal edition, providing a more in-depth analysis of the work the team has done.

As farmers know, most are both male and female—the Japanese climbing fern is an exception—individual plants are either male or female. Until now, it wasn’t clear how it was that some of the plants grew to become male, however, while others grew to be female. In this new effort, the researchers have found that it’s due to a form of intergenerational communication between the plants.

Read full article at Phys.org: http://phys.org/news/2014-10-ferns-gender.html#jCp