Terrestrial laser scanning data show that trees move their branches in a diurnal pattern, settling down for the night – as if falling asleep. So far, however, researchers have been uncertain as to why this happens.
A new study utilising time-series of terrestrial laser scanning measurements shows that changes in the water status of leaves and branches causes branches to move downward at night, up to 20 cm depending on the tree species. Leaves and branches replenish their water storage during the night, increasing their weight and causing them to droop down. Terrestrial laser scanning is a remote sensing technique that can produce a 3D representation of the surroundings with millimetre accuracy. With repeated measurements, it is possible to study small structural changes in the environment, such as the movement of branches.
“By monitoring the movement of tree branches, we can gain insight into how water moves inside the tree. Climate change reduces the availability of water and increases drought stress, so it is important to understand the movement of water in trees in order to understand changes in forest health,” Postdoctoral Researcher and the lead author of the article Samuli Junttila from the University of Eastern Finland says.
In the laboratory, the researchers found that tree branch position followed changes in tree water status also over a longer time period. These findings also have practical applications. For example, laser scanning could be used to monitor plant water status in a greenhouse to automate watering regimes and save valuable resources.
The study was conducted at the University of Eastern Finland in collaboration with the Finnish Geospatial Research Institute and the University of Helsinki. The study was conducted within the UNITE Flagship Programme funded by the Academy of Finland.
ADVANCES IN CITRUS WATER MANAGEMENT WORKSHOP
Date: May 4, 2022
With: UC Davis, UC Riverside, UC Cooperative Extension
Location: UC Riverside - Palm Desert Center, Palm Desert, CA
9:30 – 10:00 am: Registration
Morning Session – (10:00 am – 12:00 pm)
Block A - Basic principles & information for irrigation management – Moderator: S. Rios
10:00 – 10:15 am: Welcome and Updates for the Citrus production industry (A. Lopez Lopez,
Government of Baja California)
10:15 – 10:45 am: Soil-plant-water relations for Citrus (B. Faber, UCCE Ventura County)
10:45 – 11:15 am: Water Budgeting: where to find the relevant information and
how it all works together (K. Bali, UC ANR)
11:15 – 11:45 am: Methods and tools for irrigation scheduling in Citrus (D. Zaccaria, UC Davis)
11:45 – 12:00 pm: Questions & Answers
12:00 – 12:30 pm LUNCH BREAK
Afternoon Session: 12:30 – 2:30 pm
Block B - Information developed through research efforts – Moderator: E. Scudiero
12:30 – 1:00 pm: Results from the CDFA-funded research project (2018-2020) on Citrus ET/Kc
(D. Zaccaria, UC Davis)
1:00 – 1:30 pm: Strategies for Citrus irrigation management with limited water supply (B. Faber,
UCCE Ventura County)
1:30 – 2:00 pm: FRET – Forecast ETo from the National Weather Service (R. Snyder, UC Davis)
2:00 – 2:30 pm Questions & Answers
2:30 pm WORKSHOP ADJOURN
List of speakers/presenters and email contacts:
- Angel Lopez Lopez – Government of Baja California: email@example.com
- Sonia Rios – UCCE Riverside County: firstname.lastname@example.org
- Ben Faber – UCCE Ventura County: email@example.com
- Khaled Bali – UC Kearney Agricultural REC: firstname.lastname@example.org
- Daniele Zaccaria – UC Davis: email@example.com
- Elia Scudiero – UC Riverside: firstname.lastname@example.org
Rick Snyder – UC Davis: email@example.com
Western Water Systems: Update
Join us for a free webinar offering an update on Western Water Systems
Date: Wednesday – February 3, 2021
Time: 1:00P Eastern/12:00 Central/11:00 Mountain/10:00 Pacific
Kristiana Hansen - Economic Impacts from Water Reductions in
Agriculture: Examples from the Colorado River Basin
Associate Professor in Agricultural & Applied Economics | University of Wyoming
Tapan Pathak - Climate Change Trends and Impacts on
Specialist in Climate Adaptation in Agriculture | University of California Division of Agriculture and Natural Resources
JOIN us via:
Future webinar topics include: Climate Risk and Tools for Management, Credit Conditions in Agriculture, and much more!
Archives of over 100 past AIUT webinar presentations are available on the site for viewing or download.
Please register for Nitrogen Management Plan Self-Certification Webinar on Tuesday and Wednesday, November 17/18, 2020 9:00 AM - 12:00 PM PST at:
This workshop is intended for growers, and their representatives, who are looking to learn more about nitrogen management planning and/or intend to self-certify their plans. It is also a good education on how nitrogen works in our environment and how it can be managed. The program is sponsored by CA Department of Food and Agriculture, University of CA Cooperative Extension and the Ventura County Irrigated Lands Group.
Attendees must participate in both sessions to receive education credit and qualify to take the online certification test after the final webinar session.
After registering you will receive a confirmation email containing information about joining the training.
This workshop will open a half hour early at 8:30am, to allow attendees to test their connection and access the GoTo Training webinar link.
Email organizer: firstname.lastname@example.org
Image of nitrogen deficient avocado leaf on left
From Stanford: Future Water Resources
California isn't running out of water,” says Richard Luthy. “It's running out of cheap water. But the state can't keep doing what it's been doing for the past 100 years.”
Luthy knows. As a professor of civil and environmental engineering at Stanford, as well as director of a National Science Foundation center to re-invent urban water supply (known as ReNUWIt), he has spent decades studying the state's metropolitan areas.
In a new journal article, he argues that California cities can no longer rely on their three traditional water-coping strategies: over-drafting groundwater, depleting streams and importing water from far away. His analysis focuses on several strategies that, taken together, can help cities provide for their growing population with prudent public policies and investments:
Conservation is cheap, says Luthy. Eliminating lawns or taking shorter showers are behavioral changes that don't require new spending on infrastructure.
Some cities have already made great strides. Los Angeles, for example, added 1.1 million residents between 1990 and 2010, but kept total water consumption flat through conservation, as homeowners and builders install things like low-flow toilets and high-efficiency washing machines. Similarly, two dozen San Francisco Bay Area cities cut total consumption by about 23% between 2004 and 2016 even as their populations grew by 10%.
But conservation isn't enough to match population growth. Although Southern California water officials recently predicted that by 2040 expanded conservation efforts should save enough water to supply about 2.3 million new residents, officials also expect population to grow by 3.1 million by then.
California can do more, Luthy says. About 10% of water distributed in urban areas is lost to leaks. Since the last drought, California utilities have conducted water loss audits to curb such waste. “Conservation is essential to help meet urban water demand, but we also need other measures to increase supply,” Luthy says.
The reuse of non-potable water for irrigation or other purposes has a long history in California. More than a century ago, cities like Fresno were reusing sewage water to irrigate surrounding farms. In the 1980s, the Irvine Ranch Water District built a dual-distribution system that now delivers 25 million gallons per day of purified non-potable water to farms and businesses.
Cities could do the same today, but to recycle non-potable water, planners would have to build pipe networks to separate the non-potable water from the drinking water, at a cost of between $1 million to $10 million per mile.
Most short-distance opportunities have already been implemented. That still leaves new opportunities for smaller, decentralized projects where wastewater is generated and needed. The Salesforce Tower in San Francisco, for example, will soon be recycling about 30,000 gallons of wastewater a day for all purposes except drinking. Distributed non-potable reuse is also catching on with tech campuses in Silicon Valley.
The real future, says Luthy, is potable reuse – making recycled water pure enough to drink.
Potable reuse is a process that begins by purifying wastewater in treatment plants and then feeding this cleansed water back into reservoirs or underground aquifers. Water utilities then mix the recycled water with new, fresh water to meet the standards for potability.
A number of counties and municipalities are already making advances in this area.
Orange County Water District has been a leader in potable reuse and the practice of “full advanced treatment” since 2004, and many other cities have plans to recycle at least some highly treated wastewater for drinking. For example, Los Angeles is currently considering an ambitious project to recycle virtually all its wastewater to eventually make it available for potable reuse by 2035 at a cost of $8 billion. A comparable project for the San Francisco Bay Area would involve expensive upfront infrastructure, but those initial outlays could ultimately be worth it as the supply of water imported from the Sierra decreases due to climate impacts and ecosystem needs, and the cost climbs, as expected, by 60% over the next decade.
Billions of gallons of storm water simply pour into the ocean annually. That needs to change, Luthy says. California's coastal cities were historically engineered to flush out storm water to reduce flooding, but today cities want to capture as much as possible and put it to use. Los Angeles already gets 10% of its water from storm water runoff, and hopes to more than double that by 2035. Like potable reuse, however, storm water capture often requires big investments in pipes, storage sites and treatment facilities. The capital costs of such infrastructure vary widely, depending on local conditions. But the median project cost is often cheaper than costs to import water in the future, even assuming it will be available, Luthy says.
The ocean has virtually limitless water, and some communities are taking advantage of desalination to meet their needs. San Diego Water Authority's desalination system, built at a cost of $1 billion, already delivers 50 million gallons per day – about 8% of its needs. But desalinating seawater is costly and energy intensive, and can harm marine life, which is why Luthy says other communities are desalinating brackish water from estuaries where rivers meet the sea. (Brackish water has a lower salt content than ocean water, which makes it easier and cheaper to treat.)
Alameda County already produces about 10 million gallons of drinking water per day by desalinating brackish groundwater in Newark. A partnership of five agencies in the Bay Area is considering a $200 million plant that could desalinate about 20 million gallons of brackish water per day from the North Bay estuaries for about the same cost per gallon as consumers currently pay to import water from the Hetch Hetchy Reservoir.
It's an ancient story that climate change makes increasingly common: too much rain and snow in wet years, and not enough in dry ones. One way to deal with these extremes is to “bank” extra water from wet years in underground aquifers. This is possible because the state's major metropolitan areas are linked by the 400-mile California Aqueduct. Cities in the north can “deposit” water in wet years by not taking withdrawals from the aqueduct and allowing that water to be pumped out and stored instead in Kern County, heart of the agricultural region near the end of the aqueduct. In dry years, northern cities could make “withdrawals” by taking extra water from the aqueduct and rely on the water stored in Kern County to be pumped back into the aqueduct, to make sure that enough water continues to flow to cities in Southern California.
“No single one of these measures will work in isolation, but if we plan wisely now, urban water will be available when we need it,” Luthy says./h2>/h2>/h2>/h2>/h2>/h2>