If you've been talking to your plants for years, you are not alone. But know this: plants can communicate, too. They eavesdrop, sense danger in the environment, and can distinguish friend from foe. A plant under a predatory attack will emit volatile chemical cues, enabling its neighboring plants to adjust their defenses to better protect themselves.

That's the gist of what ecologist Richard Karban, professor of entomology in the UC Davis Department of Entomology and Nematology, told us back in July 22, 2015 on the publication of his landmark book, Plant Sensing and Communication (University of Chicago Press). 

Our news article, on the department website, covered his research and his 240-page book.

Karban's book is “the first comprehensive overview of what is known about how plants perceive their environments, communicate those perceptions, and learn," said  Graeme Ruxton of the University of St. Andrews, UK, co-author of Experimental Design for the Life Sciences and Plant-Animal Communication. "Facing many of the same challenges as animals, plants have developed many similar capabilities: they sense light, chemicals, mechanical stimulation, temperature, electricity, and sound. Moreover, prior experiences have lasting impacts on sensitivity and response to cues; plants, in essence, have memory."

Karban has researched plant communication in sagebrush (Artemisia tridentata) on the east side of the Sierra since 1995. His groundbreaking research on plant communication among kin, published in February 2013 in the Proceedings of the Royal Society B: Biological Sciences, drew international attention. In that study, Karban and his co-researchers found that kin have distinct advantages when it comes to plant communication, just as “the ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviors.”

A lot has happened since then. Karban continues his 40-year research, and it's continuing to draw widespread interest.

This week writer Zoe Schlanger featured him in a Bloomberg Quint article titled The Botanist Daring to Ask: Do Plants Have Personalities? 

Schlanger followed him to his field study area in Mammoth Lakes, Calif. It's part of a 156-acre reserve owned by UC Santa Barbara. She described him as "a lithe beanpole of a man with arrow-straight posture and a tuft of white hair."

"In the past 15 years or so, thanks to advances in plant genetics and a new openness toward plant research once considered fringe, botanists such as Karban have found that plants produce and respond to complex chemical signals," Schlanger  wrote. "They can detect the slightest touch. They know when they're shaded by a cloud or a fellow plant, and whether that plant is related to them. Several species can recognize can recognize their genetic kin and rearrange their bodies to avoid competing with siblings. They can manipulate predators to do their bidding and transmit electrical signals among their roots."

Read more of Schlanger's article at https://www.bloombergquint.com/onweb/do-plants-have-personalities-this-botanist-is-looking-to-prove-they-do. 

Karban, a fellow of the Ecological Society of America, is the go-to person regarding plant sensing and communication. 

We remember asking Karban: "What are 10 things to know about plant sensing and communication?" He answered:

1. Plants sense their environments and respond.
2. Although they lack central nervous systems, they process information and appear to "behave intelligently."
3. They sense the position of competitors and "forage" for light.
4. They sense the availability of water and nutrients in the soil and "forage" for these resources.
5. Their decisions are influenced by past experiences, akin to memory.
6. The respond to reliable cues that predict future events, allowing them to "anticipate."
7.  Plants respond differently to cues that they themselves produce, allowing them to distinguish self from non-self.
8. They respond differently to close relatives and strangers.
9. Plants that are prevented from sensing or responding experience reduced fitness.
10. By understanding the "language" of plant responses, we can grow healthier and more productive plants.

So the next time you see monarch caterpillars chowing down on narrow-leafed milkweed (Asclepias fascicularis), or Gulf Fritillary caterpillars skeletonizing their host plant, the passionflower vine (Passiflora), think about that. And ponder: Do plants have personalities?

Congrats, Rick Karban!

We just received word that noted ecologist Richard “Rick” Karban, professor in the UC Davis Department of Entomology and Nematology, has been named a fellow of the Ecological Society of America (ESA) for “his innovative contributions to community and evolutionary ecology, especially through providing conceptual advances and rigorous experimental work on plant-insect interactions."

Karban, an international authority on plant communication, is the "go-to" person when folks want a news story about plant communication or when scientists want to research  plant sensing and communication.

“Rick's pioneering discoveries on plant communication through volatile compounds certainly merit this recognition,” said Steve Nadler, professor and chair of the UC Davis Department of Entomology and Nematology.

Karban authored the 240-page book, Plant Sensing and Communication (University of Chicago Press), considered a landmark in its field.

ESA, in announcing its list of 27 fellows today (Feb. 6), said that its fellowship program recognizes the many ways in which its members contribute to ecological research and discovery, communication, education and pedagogy, and management and policy. 

Karban has researched plant communication in sagebrush (Artemisia tridentata) on the east side of the Sierra since 1995. His groundbreaking research on plant communication among kin, published in February 2013 in the Proceedings of the Royal Society B: Biological Sciences, drew global attention. In that study, Karban and his co-researchers found that kin have distinct advantages when it comes to plant communication, just as “the ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviors.”
 
“Plants responded more effectively to volatile cues from close relatives than from distant relatives in all four experiments and communication reduced levels of leaf damage experienced over the three growing seasons,” they wrote.

The gist of it: if you're a sagebrush and a predator (such as a grasshopper) is eating your nearby kin, another sagebrush,  it's good to be closely related. Through volatile (chemical) cues, your kin will inform you of the danger so you can adjust your defenses. Yes, plants can communicate

Karban was featured in a December 2013 edition of The New Yorker in Michael Pollan's piece, “The Intelligent Plant: Scientists Debate a New Way of Understanding Plants."
 
Karban and his graduate student, Eric Lopresti, also drew widespread interest when they announced that their woolly bear caterpillars can predict whether a Republican or Democrat will be elected to the White House.  When the population of woolly bear caterpillars (Ranchman's Tiger Moth, Platyprepia virginalis) at their research site at the Bodega Marine Reserve thrives, a Democrat heads to the White House, they said. When the population dives (as it did this year), a Republican occupies the oval office.  (See Bug Squad blog).

And why not? “Paul the Octopus had a pretty good run predicting soccer matches in 2012, so perhaps the woolly bears have earned as much credibility at forecasting this presidential election,” Karban related. Who says scientists don't have fun?

Highly honored by his peers, Karban is a fellow of the American Association for the Advancement of Science (AAAS) and recipient of the 1990 George Mercer Award from ESA for outstanding research. He was named an outstanding professor, ecology, at UC Davis in 1986.  He has published three books and more than 100 journal articles.

Karban received his bachelor's degree in environmental studies from Haverford (Penn.) College in 1977 and his doctorate in biology from the University of Pennsylvania, Philadelphia, in 1982. He joined the UC Davis faculty in May 1982 as an assistant professor, advancing to associate professor in 1988 and to full professor in 1994.

Overall, it was a great day today for UC Davis ecologists. Also selected fellows were:

• Anurag Agrawal, professor in the Department of Ecology and Evolutionary Biology, Cornell University, who received his doctorate at entomology at UC Davis in 1999, studying with Rick Karban. Agrawal was singled out his “innovative contributions to community and evolutionary ecology, especially through providing conceptual advances and rigorous experimental work on plant-insect interactions.” 
  
  
• John Stachowicz, professor of evolution and ecology, of the UC Davis Department of Evolution and Ecology  “for his fundamental contributions to the fields of symbiosis andmutualism,multi-trophic species interactions,biogeography, and invasion biology.”

ESA established its fellows program in 2012 with the goal of honoring its members and supporting their competitiveness and advancement to leadership positions in the Society, at their institutions, and in broader society, said spokesperson Lisa Lester.

The 10,000-member Ecological Society of America, founded in 1915, is the world's largest community of professional ecologists. They're committed to advancing the understanding of life on Earth, and some 4000 attend the Annual Meeting, featuring the most recent advances in ecological science. The Society publishes five journals and a membership bulletin and broadly shares ecological information through policy, media outreach, and education initiatives.

Related Links:
 

Rick Karban: Kin Recognition Affects Plant Communication and Defense
Past ESA Fellows
TED-Ed Original Lessons: "Can Plants Talk to Each Other?"

Plants can eavesdrop. They can sense danger. 

So says ecologist Richard 'Rick' Karban, professor of entomology, UC Davis Department of Entomology and Nematology, and author of the newly published book,  Plant Sensing and Communication (University of Chicago Press). 

Over the past several years, we've heard Karban speak about plant communication at UC Davis and beyond. His talks always draw an enthusiastic crowd.

Whenever I see Gulf Fritillary caterpillars chewing on our passionflower vine (yes, we planted the vine for the butterflies), I wonder what the plant is sensing with all that crunching, munching and chomping going on. Sometimes a scrub jay will swoop down and grab a beakful of caterpillars. Sometimes a praying mantis or European paper wasp will target the 'cats. Sometimes I feel sorry for the passionflower vine--especially after the 'cats have defoliated it,  leaving only scarred stems.

It's a battlefield out there, and so fascinating.

So we asked Karban "What are 10 things to know about plant sensing and communication?"

Here's the list:

1. Plants sense their environments and respond.
2. Although they lack central nervous systems, they process information and appear to "behave intelligently."
3. They sense the position of competitors and "forage" for light.
4. They sense the availability of water and nutrients in the soil and "forage" for these resources.
5. Their decisions are influenced by past experiences, akin to memory.
6. The respond to reliable cues that predict future events, allowing them to "anticipate."
7.  Plants respond differently to cues that they themselves produce, allowing them to distinguish self from non-self.
8. They respond differently to close relatives and strangers.
9. Plants that are prevented from sensing or responding experience reduced fitness.
10. By understanding the "language" of plant responses, we can grow healthier and more productive plants.

The 240-page book is a “landmark in its field,” said Graeme Ruxton of the University of St. Andrews, UK, co-author of Experimental Design for the Life Sciences and Plant-Animal Communication.

“Karban seeks to argue that plants behave—that they sense their environment, detect and communicate with an array of different organisms, and respond to their sense of the environment and communication,” Ruxton said. ”He is very successful in this, demonstrating that plant sensing and communication is a vibrant area of current research with still plenty more to discover.”

The book is “the first comprehensive overview of what is known about how plants perceive their environments, communicate those perceptions, and learn,” according to the publisher. “Facing many of the same challenges as animals, plants have developed many similar capabilities: they sense light, chemicals, mechanical stimulation, temperature, electricity, and sound. Moreover, prior experiences have lasting impacts on sensitivity and response to cues; plants, in essence, have memory."

Karban has researched plant communication in sagebrush (Artemisia tridentata) on the east side of the Sierra since 1995. His groundbreaking research on plant communication among kin, published in February 2013 in the Proceedings of the Royal Society B: Biological Sciences, drew international attention. In that study, Karban and his co-researchers found that kin have distinct advantages when it comes to plant communication, just as “the ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviors.”

“Plants responded more effectively to volatile cues from close relatives than from distant relatives in all four experiments and communication reduced levels of leaf damage experienced over the three growing seasons,” they wrote.

In other words, if you're a sagebrush and your nearby kin is being eaten by a grasshopper, deer, jackrabbit, caterpillar or other predator, communication is more effective if you're closely related. Through volatile cues, your kin will inform you of the danger so you can adjust your defenses.

Karban likened this kind of plant communication to eavesdropping.” Plants “hear” the volatile cues of their neighbors as predators damage them.

Karban is featured in the Dec. 23-30, 2013 edition of The New Yorker in Michael Pollan's piece, “The Intelligent Plant: Scientists Debate a New Way of Understanding Plants."

 

Plants communicate. They do.

Ecologist Richard Karban, a professor in the UC Davis Department of Entomology, points out that one of the simplest forms of communication involves shade.

When a plant is shaded, it grows away from the plant or other object that's shading it.

Today he published research in the Proceedings of the Royal Society B: Biological Sciences that is truly amazing readers. It involves kinship, communication and defenses.

Basically, if you’re a sagebrush and your nearby kin is being eaten by a grasshopper, deer, jackrabbit, caterpillar or other predator, it’s good to be closely related. Through volatile (chemical) cues, your kin will inform you of the danger so you can adjust your defenses.

 If you’re not closely related, communication won’t be as effective.

Kin have distinct advantages when it comes to plant communication, just as “the ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviors," Karban says. For example, fire ants can recognize kin. “Ants will destroy queens that are not relatives but protect those who are."

That ability is less well studied for plants--until now.

“When sagebrush plants are damaged by their herbivores, they emit volatiles that cause their neighbors to adjust their defenses,” Karban said. “These adjustments reduce rates of damage and increase growth and survival of the neighbors.”

“When sagebrush plants are damaged by their herbivores, they emit volatiles that cause their neighbors to adjust their defenses,” Karban said. “These adjustments reduce rates of damage and increase growth and survival of the neighbors.” 

“Why would plants emit these volatiles which become public information?” he asked. “Our results indicate that the volatile cues are not completely public, that related individuals responded more effectively to the volatiles than did strangers.  This bias makes it less likely that emitters will aid strangers and more likely that receivers will respond to relatives.” 

The research, “Kin Recognition Affects Plant Communication and Defense,” is co-authored by two scientists from Japan and two from UC Davis: Kaori Shiojiri of the Hakubi Center for Advanced Research, Kyoto University, and Satomi Ishizaki of the Graduate School of Science and Technology, Niigata University; and William Wetzel of the UC Davis Center for Population Biology, and Richard Evans of the UC Davis Department of Plant Science.

To simulate predator damage, the researchers “wounded” the plants by clipping them and then studied the responses to the volatile cues. They found that the plants that received cues from experimentally clipped close relatives experienced less leaf damage over the growing season that those that received cues from clipped neighbors that were more distantly related. 

“More effective defense adds to a growing list of favorable consequences of kin recognition for plants,” they wrote.

The researchers performed their field work on sagebrush (Artemisia tridentata) at Taylor Meadow, UC Sagehen Creek Field Station, near Truckee. They conducted four field experiments over three years “that compared the proportion of leaves that were damaged by herbivores over the growing season when plants were provided with volatile cues clipped from a close relative versus cues from a distant relative,” the scientists wrote. 

For closely related kin, they snipped stem cuttings (clones), potted them, and then returned the pots to the field. They determined relatedness “by using microsatellites that varied among individual sagebrush clones.”

The result: “Plants responded more effectively to volatile cues from close relatives than from distant relatives in all four experiments and communication reduced levels of leaf damage experienced over the three growing seasons,” they wrote. “This result was unlikely to be caused by volatiles repelling or poisoning insect herbivores.” 

Karban, who has studied plant communication among the sagebrush at the site since 1999, likened the plant communication to neighbors “eavesdropping.” They “hear” the volatile cues of their neighbors as predators damage them.

Eavesdropping. Kinship. Plant communication. Plant defenses.

Fascinating stuff.

Who knew?