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Posts Tagged: climate change

UC California Naturalist Conference, Oct. 7–9, highlights environmental challenges, diverse voices

UC California Naturalist course participants from Mid-Peninsula Regional Open Space District in the Bay Area deliver an interpretive trail program as their capstone project. Photo by Greg Ira

Climate change, extreme drought, intense wildfires and the COVID-19 pandemic can all be linked to humanity's troubled relationship with the natural world.

For more than a decade, healing and deepening connections between people and the environment have been pillars of the UC California Naturalist Program. Partnering with over 80 organizations across the state, the program – a part of University of California Agriculture and Natural Resources – has trained over 6,500 participants and certified more than 5,350 volunteers who engage fellow community members in advancing environmental stewardship and climate resilience.

To celebrate its 10th anniversary, the program is convening a statewide conference Oct. 7–9 along the north shore of Lake Tahoe, under the theme of “Celebrating Community, Nature and Resilience for a Just Future.” Keynote speakers are José González, founder of Latino Outdoors; Rhiana Jones, director of the Washoe Environmental Protection Department; and Obi Kaufmann, artist and eco-philosopher. Members of the public are invited to register for the conference.

UC Naturalists and Climate Stewards (the latter program was established in 2020), as well as instructors for both certification courses, will gather with community members to reflect on their work, share best practices and chart a path toward a more sustainable and equitable future.

Graduates of the National Forest Foundation-sponsored course for UC California Naturalists went on to intern with Cleveland National Forest. Photo courtesy UC California Naturalist program

“We're striving to create a welcoming and safe space where we can challenge our own long-standing assumptions and perspectives and hear from a wide range of voices on crucial topics, including the latest on climate change and resilience; participatory science; and equity, diversity and inclusion in the conservation space,” said Gregory Ira, director of the UC California Naturalist Program.

Ira also highlighted the conference's equity-based registration fee structure, aimed at minimizing cost as a barrier to participation.

“We encourage anyone with an interest in learning more about California's unique ecosystems – and becoming a better steward of the environment – to join us for the weekend,” he said. “We truly value the perspectives and experiences you can bring to our conference.”

The conference agenda will feature engaging presentations, hands-on workshops and field trips to the area's natural wonders. Presenters include:

  • Herman Fillmore, culture/language resources director, Washoe Tribe of Nevada and California
  • Don Hankins, Professor, Geography and Planning, Chico State University
  • Patricia Maloney, Forest and Conservation Biologist, Tahoe Environmental Research Center, UC Davis
  • Adina Merenlender, co-founder of the California Naturalist Program and UC Cooperative Extension professor in conservation science
  • Jennifer Norris, deputy secretary for biodiversity and habitat, California Natural Resources Agency
  • Ken-ichi Ueda, co-founder and co-director of iNaturalist, UC Berkeley School of Information

For more information and to register, visit the conference website at https://ucanr.edu/sites/2022CalNatCon/.  

Posted on Monday, September 26, 2022 at 1:45 PM
Focus Area Tags: Environment, Innovation, Natural Resources

Can vines speed urban cooling?

Parthenocissus tricuspidata, known as Boston ivy, growing at the Hickey Gym on the UC Davis campus. Photo by 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.”

A trumpet flower attracts hummingbirds and provides shade as it grows up a trellis beside a home in Yolo County. Photo by Kat Kerlin, UC Davis
Two research sites will be in California, with one each in Arizona, Utah and Washington.

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?"

Posted on Thursday, April 21, 2022 at 1:17 PM
  • Author: Emily C. Dooley, UC Davis
Focus Area Tags: Environment, Natural Resources

With dwindling water supplies, the timing of rainfall matters

A view of one plot in the artificial rainfall experiment at Boyd Deep Canyon Desert Research Center. Photo by Marko Spasojevic, UCR

How to help plants in drought-stricken states

A new UC Riverside study shows it's not how much extra water you give your plants, but when you give it that counts.

This is especially true near Palm Springs, where the research team created artificial rainfall to examine the effects on plants over the course of two years. This region has both winter and summer growing seasons, both of which are increasingly impacted by drought and, occasionally, extreme rain events.

Normally, some desert wildflowers and grasses begin growing in December, and are dead by June. A second community of plants sprouts in July and flowers in August. These include the wildflowers that make for an extremely popular tourist attraction in “super bloom” years.

“We wanted to understand whether one season is more sensitive to climate change than another,” said Marko Spasojevic, UCR plant ecologist and lead study author. “If we see an increase or decrease in summer rains, or winter rains, how does that affect the ecosystem?”

The team observed that in summer, plants grow more when given extra water, in addition to any natural rainfall. However, the same was not true in winter.

“Essentially, adding water in summer gets us more bang for our buck,” Spasojevic said.

Their findings are described in a paper published in the University of California journal Elementa.

Over the course of the study, the team observed 24 plots of land at the Boyd Deep Canyon Desert Research Center, in the Palm Desert area. Some of the plots got whatever rain naturally fell. Others were covered and allowed to receive rain only in one season. A third group of plots received additional collected rainwater.

While adding water in summer resulted in higher plant biomass, it generally did not increase the diversity of plants that grew, the researchers noted. Decreasing rainfall, in contrast, had negative effects on plants across both summer and winter, but may lead to some increased growth in the following off-seasons.

Implications of the work extend beyond learning when additional water resources might be applied simply to help plants grow. Whole communities of animals depend on these plants. They are critical for pollinators such as bees and butterflies, and they play a big role in controlling erosion and movement of soils by wind.

“Studies like this one are critical for understanding the complex effects of climate change to dryland ecosystems,” said Darrel Jenerette, UCR landscape ecologist and study co-author.

Desert plants also play an important role in removing carbon dioxide and nitrogen from the atmosphere to use as fuel for growth. Microbes that live in the soil can use the carbon and nitrogen released by plant roots, then send it back into the atmosphere where it can affect the climate.

“Drylands cover roughly a third of the land surface, so even small changes in the way they take in and emit carbon or nitrogen could have a big impact on our atmosphere,” said Peter Homyak, UCR environmental scientist and study co-author.

As the team continues this research over the next few years, they expect to see changes in soil carbon and nitrogen cycling, given that plants are already being affected by changes in seasonal rainfall, as this study shows.

“Can changes in precipitation patterns alter the feedback between plants and microbes, destabilizing the carbon locked in soils and sending more of it into the atmosphere? We are working on figuring that out,” Homyak said.

Editor's note: Jenerette and Homyak are affiliated with University of California Agriculture and Natural Resources through UC Riverside's Agricultural Experiment Station.

Posted on Wednesday, April 20, 2022 at 1:16 PM
  • Author: Jules Bernstein, UC Riverside
Tags: Climate Change (110), Darrel Jenerette (1), desert (5), dryland (1), ecosystem (5), Pete Homyak (2), rain (12), UC Riverside (25), Water (78), water resources (2), wildflowers (7)
Focus Area Tags: Environment, Natural Resources

Drip irrigation in arid regions can cut greenhouse gas emissions, improve air quality

Automated chambers measuring soil gas emissions in a field of young sudangrass at Desert Research and Extension Center in Imperial County. Photo by Holly Andrews

Study at Desert Research and Extension Center highlights agriculture's sustainability role

Under the blistering sun of Southern California's Imperial Valley, it's not surprising that subsurface drip irrigation is more effective and efficient than furrow (or flood) irrigation, a practice in which up to 50% of water is lost to evaporation.

But a recent study also concludes that drip irrigation can dramatically reduce greenhouse gas emissions from soil – which contribute to climate change and unhealthy air quality in the region – without sacrificing yields of forage crops alfalfa and sudangrass.

“It was really exciting to see,” said lead author Holly Andrews, a National Science Foundation postdoctoral fellow at the University of Arizona. “The crop yield was at least maintained and in some cases increased, but the water use and gaseous emissions were especially decreased under drip irrigation.”

Desert REC crucial to collecting data

Andrews and her colleagues gathered data from field studies at University of California Agriculture and Natural Resources' Desert Research and Extension Center, a crucial hub of desert agriculture research for more than 100 years. Studies in that context are increasingly important, as much of California and the Southwest becomes hotter and drier.

“We already have this history of looking at drip irrigation at this site, so our study was trying to build on that,” said Andrews, who lauded Desert REC's facilities and staff.

With more than 100 years of history as a hub for studies in a high-temperature environment, Desert REC is crucial for irrigation research. Photo by Pete Homyak

In their study published in Agriculture, Ecosystems & Environment, researchers found that – in comparison to furrow irrigation – drip irrigation in alfalfa slashed per-yield soil carbon dioxide emissions by 59%, nitrous oxide by 38% and nitric oxide by 20%.

Nitrous oxide is a greenhouse gas with nearly 300 times more warming potential as carbon dioxide, and nitric oxide is a precursor to ozone and major contributor to air pollution.

While drip irrigation only decreased water demand 1% in alfalfa, the practice led to a substantial 49% decrease in irrigation for sudangrass. For more fertilizer-intensive sudangrass, drip irrigation also reduced soil emissions of nitrous oxide by 59% and nitric oxide by 49% – the result of drip irrigation making those fertilizers more efficient.

Water management can help mitigate climate change

Studying alfalfa and sudangrass – forage crops with very different fertilizer requirements – was a strategic choice by the researchers. They are number one and number three on the list of most widely grown crops by acreage in the Imperial Valley (Bermudagrass, another forage crop, is number two).

With so much land dedicated to producing these crops, the adoption of drip irrigation at scale could deliver significant benefits to residents' health and quality of life.

“The thought that saving water can increase yields while lowering the emission of trace gases that affect regional air quality and Earth's climate is quite encouraging,” said Pete Homyak, an assistant professor of environmental sciences at UC Riverside who contributed to the study. “This is especially true for the Imperial Valley, an arid region where water is a limited resource and where residents are exposed to bad air quality.”

Homyak, who is affiliated with UC ANR through UC Riverside's Agricultural Experiment Station, said that this study illustrates how changes in water management can substantially mitigate agricultural impacts on the environment.

The study findings should encourage growers to replace furrow irrigation systems with drip irrigation infrastructure – especially in combination with financial incentives from the state, such as cap-and-trade and carbon credit programs, that can help defray high installation costs.

“It really is worthwhile if you're thinking sustainability and environmental activism in how agriculture can actually support climate change mitigation,” Andrews explained. “These practices might be a way that we can start to change that picture a little bit – and make agriculture more sustainable by tailoring irrigation management to local climate conditions.”

In addition to Andrews and Homyak, the other study authors are Patty Oikawa, California State University, East Bay; Jun Wang, University of Iowa; and Darrel Jenerette, UC Riverside.

Posted on Friday, April 8, 2022 at 8:54 AM
Focus Area Tags: Agriculture, Environment, Health

Just what is a ‘resilient’ forest, anyway?

A new suggests that low-density stands that largely eliminate tree competition are key to creating forests resilient to stressors such as severe wildfire, drought and bark beetles. Photo by Elena Zhukova

Study finds resilient, frequent-fire forests have far fewer trees

What does a “resilient” forest look like in California's Sierra Nevada? A lot fewer trees than we're used to, according to a study of frequent-fire forests from the University of California, Davis.

More than a century ago, Sierra Nevada forests faced almost no competition from neighboring trees for resources. The tree densities of the late 1800s would astonish most Californians today. Because of fire suppression, trees in current forests live alongside six to seven times as many trees as their ancestors did — competing for less water amid drier and hotter conditions.

The study, published in the journal Forest Ecology and Management, suggests that low-density stands that largely eliminate tree competition are key to creating forests resilient to the multiple stressors of severe wildfire, drought, bark beetles and climate change.

This approach would be a significant departure from current management strategies, which use competition among trees to direct forest development.

Defining ‘resilience'

But first, the study asks: Just what does “resilience” even mean? Increasingly appearing in management plans, the term has been vague and difficult to quantify. The authors developed this working definition: “Resilience is a measure of the forest's adaptability to a range of stresses and reflects the functional integrity of the ecosystem.”

They also found that a common forestry tool — the Stand Density Index, or SDI — is effective for assessing a forest's resilience.

“Resilient forests respond to a range of stressors, not just one,” said lead author Malcolm North, an affiliate professor of forest ecology with the UC Davis Department of Plant Sciences and a research ecologist with the U.S. Forest Service, Pacific Southwest Research Station. “‘Resistance' is about surviving a particular stress, like fire — but there's a lot more going on in these forests, particularly with the strain of climate change.”

Competitive nature

For fire-adapted forests in the Sierra, managing for resilience requires drastically reducing densities — as much as 80% of trees, in some cases.

“Treatments for restoring resilience in today's forests will need to be much more intensive then the current focus on fuels reduction,” said Scott Stephens of UC Berkeley, a co-author on the paper.

The study compared large-scale historical and contemporary datasets and forest conditions in the southern and central Sierra Nevada, from Sequoia National Forest to the Stanislaus National Forest. It found that between 1911 and 2011, tree densities increased six- to seven-fold while average tree size was reduced by half.

A century ago, both stand densities and competition were low. More than three-quarters of forest stands had low or no competition to slow a tree's growth and reduce its vigor. In contrast, nearly all — 82%-95% — of modern frequent-fire forests are considered in “full competition.”

The study indicates that forests with very low tree densities can be more resilient to compounded threats of fire, drought and other climate stressors while maintaining healthy water quality, wildlife habitat and other natural benefits. Forests burned by high-severity fires or killed by drought lose such ecosystem services.

Wake-up call

The authors say the 2012-2016 drought, in which nearly 150 million trees died from drought-induced bark beetle infestations, served as a wake-up call to the forestry community that different approaches are required to help forests confront multiple threats, not only severe wildfires.

A shift away from managing for competitive forests and toward eliminating competition could allow the few to thrive and be more resilient.

“People have grown accustomed to the high-density forest we live in,” North said. “Most people would be surprised to see what these forests once looked like when frequent surface fires kept them at very low densities. But taking out smaller trees and leaving trees able to get through fire and drought leaves a pretty impressive forest. It does mean creating very open conditions with little inter-tree competition. But there's a lot of historical data that supports this.”

“We think resilient forests can be created, but it requires drastically reducing tree density until there's little to no competition,” said Brandon Collins of UC Berkeley, another co-author on the paper. “Doing this will allow these forests to adapt to future climate.”

Additional co-authors include Ryan Tompkins of UC Cooperative Extension, and Alexis Bernal and Robert York of UC Berkeley.

The study was funded by the National Park Service Pacific West Region, U.S. Forest Service Pacific Southwest Research Station, U.S. Joint Fire Sciences Program, and the UC Agriculture and Natural Resources Division.

Posted on Wednesday, January 19, 2022 at 11:28 AM
  • Author: Kat Kerlin, UC Davis
Focus Area Tags: Environment, Natural Resources

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