By Mary O’KEEFE

I recently listened to a radio program from BBC’s CrowdScience titled “Do plants know we’re here?”

It was fascinating (as most CrowdScience programs are) but this one really held my attention from beginning to end. 

It all started with a CrowdScience listener who had been at a retreat where she was encouraged to “hug a tree.” She found it very comforting but wondered if the tree felt her presence. 

In the radio program, the conclusion reached after speaking to a number of biologists and horticulturalists, is that plants find stressful the whole experience of being touched. 

“In terms of humans, I think they [plants/trees] won’t necessarily know a human or even an individual human. They certainly wouldn’t be aware of that level of specificity – but they would if they were in a small room. If a human walked in, they would be breathing out carbon dioxide and the plant would immediately be aware of that change in the air,” according to Alexander Jones with the Sainsbury Laboratory at the University of Cambridge in the UK. 

He added that if humans turn on a light or open a window the body of the plant would respond to it – even if only for a short while. 

“According to Alexander, just by being around plants we would change their environment in ways they can detect and respond to in measurable ways. So we can measure genes – gene expression going up or down in response to these stimuli very fast,” according to the BBC radio show.

It is believed that plants recognize different types of stimuli, for example a bug crawling across their leaves. 

And some interaction with specific bugs, like spider mites, trigger a specific reaction from the plant. 

“You might be familiar with spider mites crawling all over your house plants. They’re actually terrible pests,” Jones said. “We found that when spider mites feed on a leaf, they will actually trigger a drought hormone. This drought hormone is normally used to save water by closing pores on the leaf but the plant can do the same thing to defend against spider mites.”

So plants respond to us, and to pests, in a variety of ways. Which to me just enforces the fact that we must respect nature around us because what we do affects it. 

I love walking along the trails around us. Mountain Oaks and Deukmejian Wilderness Park are really nice trails to walk, especially in the mornings. Descanso Gardens is another one of my favorite walks. 

“There is growing medical evidence that immersing oneself in a forest environment can have significant physical and mental health benefits,” according to psychiatry.org.

The Global Wellness Institute also speaks about the advantages of walking in the forest, which they call forest bathing and forest therapy. It is the practice of just taking in the forest atmosphere. 

There have been studies that do show how just walking through a forest and listening to the sounds around you can improve mental wellness.

As reported in Global Wellness: A study in 2010 at Chiba University in Japan found that forest environments promote lower pulse rate, blood pressure and concentrations of cortisol, and greater parasympathetic and lower sympathetic nerve activity than do city environments.

A small 2017 Nippon Medical School study compared the impact of a three-day forest bathing trip to a city trip with exercise. It found the forest bathing trip significantly increased natural killer (NK) activity. NK cells are specialized white blood cells that act as rapid first responders in the body’s innate immune system to destroy virus-infected and cancerous cells. The numbers of NK cells increased, along with the expression of intracellular anti-cancer proteins, while the concentration of adrenaline in urine with increased NK activity lasting more than seven days significantly decreased. In contrast the city trip did none of these things. 

Another study done in 2017 in Japan found that forest bathing has hypertensive effects: SBP (systolic blood pressure) and DBP (diastolic blood pressure) in the forest environment were significantly lower than in non-forest environments. They found it had a bigger effect on those with high blood pressure and those people in middle age and older. 

A study from National Taiwan University found a two-hour forest bathing experience led to changes in autonomic nervous system activity and emotions. Heart rate and systolic and diastolic blood pressure were significantly lower after the short experience while the mood scores were also significantly lower for “tension-anxiety,” “anger-hostility,” “fatigue-inertia” and “depression-dejection.”

Every time my dad and mom came out to California my dad had to sit outside for a while. It didn’t matter if it was cold, hot or raining – he needed time outside. I would join him and we would just sit and listen to the birds and squirrels … and of course my kids yelling for me to find something that was right in front of them. 

I realized that Dad knew about the therapy of forest and outdoors in general before there were studies about it. I think that was because he was brought up in a farm world. I also remember that when we went to visit family at their farms we rarely were inside. In fact, I don’t think I could describe the interior of my uncle’s home – but I knew every inch of his acreage. 

I have also found the older I get the more I want to spend time out in nature, even if it’s in my backyard. I find that if I don’t take time to garden I am sad. Dad always said you can check your priorities in your garden. If you have weeds your priorities are off. 

We are so lucky to live in a community when all we have to do is walk just a few steps outside our homes and hear those wonderfully loud parrots flying by or come face-to-face with crows that are as big as cats.

So my advice as we move into fall is to take time to take a walk through nature without listening to the latest podcast or even music. Listen to nature … because it is definitely listening to us. 

For those who would like to listen to BBC’s CrowdScience, go to 

https://www.bbc.com/audio/play/w3ct8k7h.

Weather report from Gregg Inboden:

As of Tuesday at 6:30 p.m. in La Crescenta, the outside temperature was 80 degrees, humidity 30.35. Both are pretty typical for this time of year. Wind at 2 mph but has been as high as 7 mph at various times.

  No measurable rain is expected this week but (as we have heard) we are expecting a pretty severe El Niño this fall and winter. We’ll be getting darker earlier – sunset at 6:40 p.m. and sunrise at 6:47 a.m.

  Fall is put on hold as we face another heatwave. The Weather Service has issued an extreme heat wave watch that will be in effect from Oct. 2 at 10 a.m. to Oct. 8 at 8 p.m.

Today and on Friday the temperatures are expected to reach triple digits and temperatures will continue to ramp up through next week. There will be two heat peaks, one focuses on Saturday and another one will occur in the middle of next week, according to NOAA.