Posts Tagged: Climate Change
This is one of a series of stories featuring a sampling of UC ANR academics whose work exemplifies the public value UC ANR brings to California.
Farmers are already seeing the effects of warmer winter nights and hotter summer days on their crops. Climate change is gradual, but increasing overall temperatures affect many aspects of farming, including where and how crops are grown. Tapan Pathak, University of California Cooperative Extension specialist based at UC Merced, is doing applied research that farmers and ranchers can use to adapt to new conditions created by a variable and changing climate.
“You don't have to shift your practice tomorrow, but if you are thinking of making a 30-year investment, it's important to know what risks there are for planting different crops,” said Pathak, who is based in the Sierra Nevada Research Institute at UC Merced.
Pathak co-chairs the UC Cooperative Extension Climate Change Program Team, whose mission is to increase the capacity among UCCE academics to address climate change concerns with science-based information. Pathak also collaborates with extension professionals from across the western U.S. to do extension events related to climate change adaptation. He works closely with state and federal agencies statewide and growers to identify changes occurring as a result of climate change that affect agriculture. Pathak's research will inform growers' decisions, such as crop variety, planting and harvest dates, extreme heat and frost protection and pest management.
“We are seeing impacts of climate change, that's evident. We have some solutions that are available, but we also need to do more locally relevant crop specific research to make agriculture resilient to climate risks,” Pathak said.
The UCCE scientist was the lead author on an important paper that synthesized the impacts of climate change on California agriculture and offers directions for future research and implementation. The authors concluded that almost all of California's crops, collectively valued at more than $50 billion a year, will be endangered to some degree by rising temperatures and variable weather patterns. The study “Climate Change Trends and Impacts on California Agriculture” was published in Agronomy in 2018.
“I think there's a lot of solutions available and there is also a clear need for adaptation research that include growers' perspectives,” said Pathak, who received a Climate Leadership Award for research from the California Climate & Agriculture Network.
Pathak is also collaborating very closely with UC Davis-based UCCE specialist Daniele Zaccaria, who is leading an international project on evaluating bioclimatic indices and developing the index that is more relevant to irrigated agriculture, which includes scientists from the U.S., Italy, Brazil and Chile.
“A bioclimatic index specific to irrigated agriculture can provide more accurate and valuable agricultural drought information that could be helpful for water resources planning and management decisions,” Pathak said.
Pathak is developing a web-based decision support system called Cal AgroClimate to help growers make decisions, in partnership with the USDA California Climate Hub director Steven Ostoja. It is being built on the same platform as AgroClimate, which is popular with growers in the Southeast.
Cal AgroClimate translates historical climate data and future projections into a useful decision support system for growers. For example, growers can get extreme heat and frost advisories for the next 10 to 14 days in their region and relevant resources to mitigate risks for their selected crop. It is in the early phase of development and will include a suite of tools based on the needs and priorities identified by UCCE colleagues, growers and the agricultural community in general.
In addition to his work on Cal AgroClimate, Pathak has been conducting research on specific crops.
In a study looking at processing tomato production in the Central Valley, Pathak and UCCE advisor Scott Stoddard found that changing temperatures will likely change the tomato growing season. The scientists looked at processing tomato data starting from 1950 and projections for 2030-2040 to see how the time to maturity is changing.
“In general, the time from emergence to maturity, the timeframe for processing tomatoes in that region is going to shrink by two to three weeks,” said Pathak. “A lot of processors have their timeline for when they need the tomatoes for processing and so when you have this shift in the phenology, that alters the timeframe for when they mature and are ready for the processors. So, there's a whole shift in the management that growers might have to think about in the future.”
To identify the climate information almond growers need to take adaptation action, UC Berkeley postdoctoral researcher Kripa Jagannathan, former UCCE advisor David Doll and Pathak interviewed almond growers in the Central Valley. During their conversations with farmers, the researchers clarified that long-term climate projections are not seasonal forecasts or weather forecasts for the next 20 to 30 years. The projections provide information on trends or potential of shifts from historical conditions for making long-term planning decisions.
Pest control is one area where growers will need to make changes. Research by UCCE advisor Jhalendra Rijal and Pathak shows the almond pest navel orangeworm is already extending its life to a fifth generation during a season.
For strawberries, Pathak, UCCE entomology and biologicals advisor Surendra Dara and postdoctoral researcher Mahesh Maskey have developed a model to forecast weekly crop yields based on weather data. “The model was pretty accurate for the Santa Maria region,” Pathak said. “A crop-specific model can be used for labor management not just crop management.”
Because California produces more than 400 agricultural products, adapting to climate change will be more complex than in other states.
Around the world, countries have established protected areas as the primary defense to reduce widespread biodiversity loss and guard vulnerable habitats. However, species and ecosystems are adapted to particular climates—as those climates shift across and outside of protected area boundaries, species may track them into unprotected landscapes where human land uses degrade conservation potential.
In a new study published in Science Advances today, Berkeley researchers offer a broad analysis of how protected areas will continue to capture the climates suitable for species into the future. The study was led by Paul Elsen, a climate adaptation scientist at the Wildlife Conservation Society and former postdoctoral researcher in the Department of Environmental Science, Policy and Management, and it was co-authored with Cooperative Extension specialist Adina Merenlender, recent Ph.D. graduate Eric Dougherty, and Bill Monahan, currently with the U.S. Forest Service.
The authors first determined how climate is expected to change within all terrestrial protected areas globally by utilizing data from several major global climate models and maps of protected areas. They found that over the next 50 to 80 years, the total amount of protected land situated in both warm and cold climates, over a wide range of annual precipitations, is expected to decline significantly.
“We calculate that most countries will fail to protect over 90% of their available climate at current levels, forcing many species to shift into unprotected lands,” says Merenlender.
Species or ecosystems adapted to specific climatic conditions would disproportionately be impacted, such as those in tropical and subtropical moist broadleaf forests, boreal forests, tundra, savannas, grasslands and shrublands.
The authors then tested how different mitigation and adaptation strategies might work to limit the amount of change species may experience in protected areas within countries, thereby reducing species' vulnerability. For example, they investigated whether greenhouse gas mitigation or the addition of new protected areas were more effective for building resilience to climate change.
“Protected areas are invaluable to conserving biodiversity, but where those protected areas are positioned in relation to available climates can have a huge influence on their ability to reduce species' vulnerability to climate change,” says Elsen.
If countries were to expand protected areas to double the diversity of climates under protection, the authors find, they would retain 118% more land area of today's protected climates into the future. By contrast, reducing greenhouse gas emissions in accordance with global targets would increase retention of currently protected climates by 102%.
“If we adopt a strategy for increasing protection that seeks to maximize the diversity of climate types represented within protected areas—for example, cold, warm, hot, wet, temperate, arid, etc.—we stand a much better chance that protected areas will continue to encompass the climatic conditions that support currently protected biodiversity,” says Elsen, lead author of the study.
The authors were surprised to find that simply establishing more protected areas wasn't the solution to building resilience. “Whether it's ‘half-earth' or a more modest target, we need more protected areas but they must be climate smart,” says Merenlender. “This means protecting a full range of climate types, or parks will not protect biodiversity as intended into the future.”
The long-term conservation potential of protected areas depends on careful maintenance of appropriate biotic and abiotic conditions that promote biodiversity. The authors stress that decisions about land use, which are socio-economic in nature, need to also account for conservation and ecosystem health. “Species that track climate into unprotected landscapes may face landscapes that are highly modified by agriculture, infrastructure, development, and other human activities, so it is still critical that we work to increase the suitability of unprotected lands for biodiversity, too,” says Elsen.
The study includes recommendations for planning for future reserves that stand to better protect biodiversity and will be more resilient to climate change over the long term.
Read the study on the Science Advances website.
We would like to congratulate the 13 Imperial County farmers who received a total of $1,073,697.97 from CDFA's Healthy Soil Incentive Program.
California Department Food and Agriculture (CDFA) has been providing financial initiatives to California growers and ranchers through its Healthy Soil Program to enable farmers to implement conservation management practices that sequester carbon, reduce atmospheric greenhouse gases (GHGs), and improve soil health.
These 13 award-winning projects will reduce GHG emissions by an estimated 3,689.1 metric tons of carbon dioxide per year, which is equivalent to 797 passenger vehicles driven for one year.
This is a groundbreaking achievement for our county and a huge jump from last year's HSP solicitation period, demonstrating that farmers in this region are becoming very interested in adopting climate smart agricultural practices, provided they have funding.
“These climate smart agriculture incentive programs assist farmers in doing their part to try to sequester carbon and help sustain the environment,” Ronnie Leimgruber, one of the 13 Healthy Soils grant recipients, says. “Being awarded this grant will allow me to apply more compost than I normally would.”
2020 is the first year that Imperial County growers and ranchers applied for the Healthy Soil grants, which began in 2017.
With a maximum award of $100,000 per award, this grant was a great opportunity for California farming operations to pilot conservation management practices such as compost application, cover crops, nutrient management, and reduced till/no till for 3 to 10 years (depending on the practice) with minimal financial investment on their part. For the farmers and ranchers interested in the environmental benefits but unable to afford the cost of implementing these practices on their own, this program is a chance to try them firsthand.
UC Cooperative Extension in Imperial County and Imperial County Farm Bureau partnered to provide technical assistance for the Healthy Soils Program and Alternative Manure Management Program for 2020. Together we conducted outreach, held a series of workshops and assisted individuals with their grant applications.
The goal was to bring awareness to these climate smart agriculture incentive programs and assist growers in applying and maximizing their chances of receiving grants. Overall, Imperial County saw great progress from the prior year in the number of applicants and amount of awards, drawing recognition from Assemblymember Eduardo Garcia.
We are optimistic that these programs will continue to grow in future years, assisting local farmers in implementing additional farming practices that continue to benefit the environment. We encourage grant recipients to contact us for assistance with project implementation and data collection.
This year, CDFA's Healthy Soil Incentive Program received a total of 578 applications requesting $37.87 million, exceeding the $22 million available funds.
CDFA secretary Karen Ross stated, "Soil has the transformative power to help us stabilize our changing climate by capturing greenhouse gas emissions from the atmosphere and storing them underground, through the assistance of living plants and microbes, that improve both the atmosphere and the soil."
These conservation management practices are known to promote on-farm sustainability by building organic matter, encouraging nutrient cycling, increasing water holding capacity, reducing soil compaction, and lessening the need for synthetic fertilizers. In general, if you enrich your soil, it will boost the productivity of your cropping systems. However, every agricultural operation varies in its needs, the benefit it obtains from different conservation management practices depends on the location, size, crop rotation, irrigation system, and soil type. To enhance applicability according to site specific needs, CDFA allows applicants to choose from four categories, totaling 28 eligible practices selected from the United States Department of Agriculture (USDA) Natural Resources Conservation Services (NRCS) conservation practices standards.
For more information about climate smart agriculture, please contact me, Kristian Salgado, at email@example.com or at (442) 265-7700.
“There are lots of invasive pests everywhere because of global warming and the movement of plant materials in general,” said Philippe Rolshausen, UC Cooperative Extension subtropical tree specialist at UC Riverside.
Yellowing leaves, a thinning canopy and branch die-back are symptoms that the tree is sick. UC Master Gardeners, headquartered in UCCE county offices across the state, can provide free help, the article said.
Marantos listed possible reasons for common tree symptoms:
Yellow leaves: May be due to a lack of nutrients. A sudden jolt of fertilizer isn't the best solution. Homeowners often remove the best fertilizer and mulch for trees — their own fallen leaves.
Thinning canopies and branch die-back: May be the result of a soil-born disease, such a phytophthora, caused by excessive water. “Homeowners have a tendency to over-irrigate a tree that's not doing well, but soil-borne diseases actually thrive in wet soils, so that's making things even worse,” Rolshausen said. “Trees don't like standing water on their root systems because they can't breathe.”
Huanglongbing of citrus: Invested trees send up shoots of bright yellow leaves. Eventually, new leaves get twisted and mottled and the fruit stops ripening. The disease was first spotted in Southern California in the late 1990s and has since been detected in Los Angeles, Orange, San Bernardino and Riverside counties, according to a map prepared by University of California Agriculture and Natural Resources.
The Times article also recommended the UC Integrated Pest Management Program website to learn how to diagnose and control tree insects and diseases.
National Public Radio highlighted a growing concern for San Joaquin Valley tree fruit and nut farmers - diminishing winter chill in an age of climate change. "Warm winters mess with nut trees' sex lives," reported Lauren Summer on Morning Edition.
For example, adequate winter chill allows female and male pistachio trees to wake up simultaneously, which is ideal for pollen to be available for wind to carry it to blooms on female trees.
Fresno State agriculture professor Gurreet Brar, a former UC Cooperative Extension advisor, is testing whether horticultural spray application at different chill-hour intervals will trick trees into thinking they've been colder. Normally, the spray is used on fruit and nut trees to control insects, but it's also known to alter the tree's dormancy period.
"It's supposed to help the tree and buds wake up normally and have a normal bloom," Brar said.
Summer also spoke to Katherine Jarvis-Shean, UC Cooperative Extension orchard systems advisor in Yolo County.
"We're on this (climate change) march and it's really just a matter of how bad it's going to be, not whether it's happening or not," Jarvis-Shean said. "Threatening those crops is really threatening the livelihoods of a lot of Californians."
Fruit and nut trees that require the most winter chill will run into trouble by mid-century, when experts predict consistently warmer weather, Summer reported.
"Bing cherries, which is really the marquee variety in California, won't get enough chill," Jarvis-Shean said. "We'll need to be breeding new varieties that still have that rich ruby flesh and that juicy flavor that can do well under those low chill conditions."
Better-adapted trees may be the only strategy in the long-run, she said. Efforts are already underway to breed new varieties of pistachios that can handle warmer winters.