- Author: Emily C. Dooley, UC Davis
Study explores cooling benefits of fast-growing vines as trees take their time
Perhaps trees aren't the only green solution when it comes to cooling urban spaces and reducing energy costs. Honeysuckle, Virginia creeper, pink trumpet and other vines could be a fast-growing substitute in climate-smart cities of the future.
Researchers from UC Davis are leading a nearly $880,000 federal grant to study how vines may provide cooling and shade in Western states in less time than it takes a tree to grow tall.
“Vines can quickly shade buildings and reduce energy consumption while trees slowly grow to maturity,” said Alessandro Ossola, an assistant professor of plant sciences who is a principal investigator for the project. “We believe vines can be an effective and cheap measure to help cities accelerating climate change adaptation.”
The grant from the U.S. Department of Agriculture's Agricultural Marketing Service will fund work to plant and monitor at least 10 types of vines on trellises in five locations in different climate zones over three years. California Department of Food and Agriculture is administering the grant.
Using less water
Water conservation will be vital as populations rise, climate extremes become more prevalent and the demand for agricultural and drinking water increases. The goal of this research is to identify vines that can help save energy by providing cooling and reduce the need for irrigated water.
“In addition to rapid growth rates, vines can be easily integrated with structures to maximize potential cooling effects,” said Loren Oki, a Cooperative Extension specialist with Department of Plant Sciences, who is the project lead. “But we need to understand the relationships between low water-use plants and their ability to reduce thermal loads on buildings.”
The vines will be planted, supported by a trellis and watered regularly during the first growing season to establish deep roots and healthy shoots. Over the next two years, the vines will experience low, moderate and high water allocations.
The vines will be rated on aesthetics, foliage quality, floral quantity, pest and disease resistance, appearance and other factors. Thermal images of trellis coverage and other environmental measurements will also be taken to assess shading and cooling potential, according to grant documents.
Many vines can be grown along cables and wire nets that are actually detached from walls to avoid direct contact and still provide shade, Ossola said.
“We want to understand which vine characteristics relate to fast growth, reduced water use and increased aesthetic appeal,” he added.
Outreach and education
The findings will enable recommendations to be developed for regions, planners, the landscape industry and the public. It could lead to plants being designated as “water-wise,” “low-water use,” “energy-saving” or “cooling.”
Extensive engagement and outreach will also publicize the information.
“Climate change is a great opportunity for the horticultural industry to innovate and promote climate-ready plant productions,” Ossola said.
USDA funding supports research across state lines to find innovative solutions to regional and national problems, USDA Under Secretary for Marketing and Regulatory Programs Jenny Lester Moffitt said in a news release announcing this and other grants.
“This year's funded projects will address a range of those challenges, from energy and water saving in vine plants, finding cost-effective solutions for heat tolerance and drought, to addressing food safety risks for produce,” Moffitt said.
Scientists from the University of Arizona, University of Washington, Utah State University and the South Coast Research and Extension Center at UC Agricultural and Natural Resources are contributing to the research and will be overseeing vine sites in their states.
This article is reprinted from the UC Davis College of Agricultural and Environmental (CA&ES) website, where it is titled "Could Vines Be the Answers to Speeding Urban Cooling, Water Reduction in the West?"
- Author: Ben Faber
If you missed the recent UC/CAS/CAC grower meeting on cooling avocado trees or just want to review the enormous amount of information or just want to wander other grower's orchards, Here is the video of the presentations:
Mitigating Heat
- Author: Lenya Quinn Davidson
Reposted from the Fire Adapted Communities Learning Network
On Labor Day weekend, my friends and I canceled a vacation rental on the Trinity River because of the heat and smoke. It was predicted to be 112 degrees inland that weekend, and we figured we'd be crazy to subject ourselves (and our posse of toddlers) to that when we could stay on the coast and enjoy fresh air and cool temperatures. Smart, right?
Saturday morning, we made breakfast at my friend's house and watched the temperature climb. By 10 a.m., it was over 80 degrees, and by noon, it was nearing 100 — unbelievably hot for our foggy redwood coast. And on top of the heat, it was the smokiest I've ever seen it here. Turns out, we hadn't escaped the heat or the smoke.
But here's the weird thing: the inland areas, which were predicted to be unusually hot that weekend, were actually cooler than the coast. My husband, who was working on the Eclipse Complex in the Klamath Mountains — in the heart of the projected heat wave — experienced a high in the low 80s that weekend. Meanwhile, we were grappling with almost unprecedented heat here by the ocean. To have a double-digit difference in temperature between the inland areas and the coast is the norm here, but the coast is never the hotter of the two.
The odd temperature patterns that weekend reminded me of an old paper I read years ago — something about the cooling effects of forest fire smoke, and the potential to use wildfires to better understand the potential impacts of “nuclear winter.” An odd topic, but intriguing, too.
Interestingly, in looking back at the paper, I realized that it was based on data collected in the Klamath Mountains exactly thirty years before this year's hot, smoky Labor Day weekend. The author, Alan Robock, analyzed surface temperature data from weather stations across northern California and southern Oregon, and he found that smoke from nearby wildfires had significant cooling effects in the Klamath River canyon in September of 1987 — temperatures were more than 27 degrees below normal for an entire week and more than 9 degrees cooler than normal for most of the month. During that time, the combination of an inversion and wildfire smoke created a positive feedback loop: smoke trapped by the inversion cooled the surface air temperature, which strengthened the inversion and trapped even more smoke. Of course, the smoke did more than cool the air that month; Robock notes that it also caused severe respiratory problems for people who were living in that area, and even caused tomato plants to shrivel up and die.
More recent studies show other important effects of temperature inversions. Earlier this year, Becky Estes and others published a paper in Ecosphere that looked at the factors influencing fire severity in the Klamath Mountains in 2006 — a year that had moderate burning conditions and is thus representative of years when wildfires might be managed for resource benefit. Of all the weather variables they looked at, temperature inversions had the strongest influence on fire severity that year. Earlier work by Miller et al. (2012) had noted similar patterns, including more surface fire and less crowning under inversions. 1987 and 2008, two of the biggest fire years in our region in the last several decades, had lower than average fire severities thanks to widespread temperature inversions.
Collectively, these studies reveal interesting tensions between humans and fire — not just here in the Klamath Mountains, but everywhere. In some ways, the inversions and smoke are producing conditions we want to see on the ground: lower fire intensities, cooler temperatures, etc. But these can come at the cost of unlivable air quality (not to mention stunted vegetables and wine that tastes like smoke!). And this isn't just about inversions — it's really about us finding ways to live in the crossfire of the natural checks and balances of these systems. We know that we need more fire, and that we need to take advantage of moderate burning conditions, even if that means more smoke. We just need to find good ways to do it — that's what fire adaptation is all about. (Also, I'd be lying if I said Robock's thoughts on nuclear winter didn't seem a little more relevant now than they did last time I read that paper … might be worth revisiting!)
References
Estes, B. L., Knapp, E. E., Skinner, C. N., Miller, J. D., & Preisler, H. K. (2017). Factors Influencing Fire Severity Under Moderate Burning Conditions in the Klamath Mountains, Northern California, USA. Ecosphere, 8(5).
Miller, J. D., Skinner, C. N., Safford, H. D., Knapp, E. E., & Ramirez, C. M. (2012). Trends and Causes of Severity, Size, and Number of Fires in Northwestern California, USA. Ecological Applications, 22(1), 184-203.
Robock, A. (1988). Enhancement of Surface Cooling Due to Forest Fire Smoke. Science, 242, 911-913.
/h2>- Author: Mary E. Reed
There is a wide schism between the sleek mechanical harvesting machines that briskly traverse California’s fertile croplands versus the field worker with a machete and head-basket, or possibly a donkey laden with woven baskets, that is still most commonly found in many nations.
Produce loss continues to be a significant problem. Worldwide, it is estimated that as much as one-third of the produce grown is never consumed by humans (Kader, 2005). Many logistical challenges contribute to this loss, including: ineffective or absent cooling systems, slow and rough transportation, physical damage from rough handling, and poor sanitation conditions.
In 2010, one of the most popular free titles available on the Postharvest Technology Center’s web site was “Small-Scale Postharvest Handling Practices: A Manual for Horticultural Crops”. Written by Lisa Kitinoja and Adel Kader, and currently translated into 10 languages, this title was downloaded by over 22,000 readers last year. While this useful resource is very popular in the United States among small-scale farmers, over 8,000 readers benefitted from the useful content translated into Indonesian, 4,000 from the Vietnamese translation, and over 3,000 from the Arabic translation. Readers learned information about the curing of tuber crops, designing picking poles and catching sacks to gently harvest fruit, and efficient designs for packinghouse layout. (View all ten translations under the section on “Small-Scale Postharvest Practices” at: http://postharvest.ucdavis.edu/Pubs/publications.shtml.)
“Many simple practices have successfully been used to reduce losses and maintain produce quality of horticultural crops in various parts of the world for many years,” asserted Lisa Kitinoja of Extension Systems International. “You don’t necessarily need costly handling machinery and high-tech postharvest treatments to be able to deliver quality produce to the marketplace. However, effective management during the postharvest period is key to reaching the desired objective.”
While most California produce shoppers are grateful for the quality and variety available in our markets, it’s nice to know that an effort is being made to improve the produce available to others not quite as fortunate as we.
Photo: Kumasi Retail Produce Market, courtesy of Adel Kader.
- Author: Mark Bolda
In some of the first literature written in Japan in 1939 (Kanzawa, T.) about spotted wing drosophila, Drosophila suzukii, (SWD), experiments were made regarding the sensitivity of the egg and larval stages of spotted wing drosophila to periods of temperatures above and below freezing (32o F).
As is noted in the two graphs below, at constant temperatures of up to 35o F, 96 hours or more of cooling resulted in total mortality of spotted wing drosophila eggs and larvae. This was also anecdotally confirmed in tests conducted in 2009 in California.
While temperatures below freezing are not useful to fruit shippers, temperatures in the area of 35o F are. However, it is important to note that for success the constancy of the temperature is critical. So, while in an ideal situation constant temperatures of 35o F or a little below are effective in SWD egg and larvae suppression when extended for periods longer than 96 hours, the reality can vary significantly from the ideal. Shipped fruit ordinarily do not experience lengthy regimes of constant temperature as they are moved from place to place. Temperatures of a refrigerator truck can vary by location inside and placement of the produce (ie on the side, towards the bottom etc.), and certainly the temperatures at the point of sale can vary from the ideal to room temperature to even warmer.
Additionally, while initial damage from SWD on raspberries, blackberries and strawberries can be difficult to detect, this is not the case for other fruits such as cherries or blueberries, where the activity of SWD will leave an unsightly blemish.
The take home message from this information is that while extended cooling can be suppressive of SWD, growers should not rely on cooling alone. It will still be important to manage SWD in field.
Thanks to Shinji Kawai for making the information from the 1939 Kanzawa paper available.