- Author: Janet S Hartin
To date, over 2,000 climate-ready shade trees and tips on their planting and long-term care have been provided by UC Master Gardeners and over 20 partners to residents of low shade neighborhoods in San Bernardino and Riverside Counties through the “Trees for Tomorrow Start Today” project. Tree species given away are identified from research projects including the joint University of California/United States Forest Service (USFS) study at UC Riverside as well as from other research, local observations, and input from the green industry and academic colleagues.
Why is this project so important? 95% of Californians now reside in cities and suburban environments. Resulting urban heat islands created by built environments coupled with impacts of climate change can be mitigated through nature-based solutions. Planting climate-ready shade trees now will help ensure cooler urban areas in the next several decades as trees mature and maximize their urban ecosystem benefits. Fortunately, the shade from a single well-placed tree can decrease surface temperatures of black asphalt and artificial turf by more than 70 degrees F in hot inland and desert cities. Studies show that surrounding air temperatures can also be reduced through the transpiration process.
A major goal of the"Trees for Tomorrow Start Today" project is to enhance tree canopy cover in low shade neighborhoods also plagued with much higher than average levels of air pollution and pulmonary and cardiovascular disease incidence. Events over the past month have occurred in Fontana, San Bernardino, and the Salton Sea.
Thank you to all our partners and, especially, our tree recipients, for greening and cooling your yard and neighborhood! 
- Author: Janet Hartin
Welcome to Fall!
It's my favorite season and likely for many of you, as well. Beyond the holidays and extra time with family and friends, nature radiates its beautiful hues. In addition to lovely foliage, deciduous trees often expose exquisitely shaped and sturdy trunks. And, of course, there is the lovely fall foliage showcased by many species.
Did you ever wonder why trees "turn" color in the fall? The short answer: It's primarily a function of long, cool fall nights and short, sunny days. The longer answer? Chlorophyll is responsible for the basic green color of leaves we see in spring and summer and is a necessary component of photosynthesis, which uses sunlight to manufacture sugar (food) that is stored during the dormant period of the year. Carotenoids produce yellow, orange and even brown pigments in crops such as carrots, squash, bananas and many ornamental plants such as daffodils and poppies. Anthocyanins are red and orange in color and are most linked to lavish displays of brilliant fall foliage. They also give rise to coloring of strawberries, plums and cherries.
Here's the kicker: While chlorophyll and carotenoids are present in leaf cell chloroplasts throughout the entire growing season, during fall chlorophyll begins to break down. Voila! The lovely yellow and orange hues we all look forward to seeing are finally exposed. In addition, red hues (called anthocyanins) are produced in fall. So, in reality foliage doesn't "turn" orange or red at all.
Interestingly, the actual timing of color change varies across species and appears to be genetically inherited. The same species will exhibit a similar color scheme in cool temperatures in higher elevations at nearly the same time as it does in warmer lower elevation climates.
The intensity of color can vary quite a bit however. Where do temperatures enter the picture? Both the amount of color and the overall intensity of fall color is very linked to weather conditions that occur prior to and during the actual time the chlorophyll in leaves winds down. The most brilliant displays occur after several warm, sunny days and cool, crisp (above freezing) nights. This is because although lots of sugars are made in leaves during sunny daytime hours, the corresponding cool nights prevent the sugars from moving out. The amount of soil moisture also helps ensure that from year to year fall colors vary even in the same trees. So, either a late spring or a prolonged drought can both delay the display of fall color by a few days or even a few weeks.
What's the recipe for the most brilliant fall display? Most likely a warm, moist spring followed by a warm summer and sunny fall with cool autumn nights. Although fall color is not nearly as spectacular in lower elevations of Southern California compared to other colder areas of the nation, the liquidambar or American sweet gum (Liquidambar styraciflua) offers some pretty impressive fall color and an impressive 300 to 400-year life span. (Did you know that liquidambar got its name because it at one time was a sought-after chewing gum for Native Americans?)
Two “climate-ready” tree species with lovely fall foliage that grow in both the west portion of the county and the desert are the ‘Keith Davey' Pistache, a large street and park tree sporting crimson to scarlet colored foliage and its relative, the ‘Red Push' Pistache, a hybrid between P. atlántica x P. integerrima) which has lovely red foliage as it emerges in Spring as well as Fall. Others include the Raywood Ash (Fraxinus oxycarpa 'Raywood') sporting a reddish-purple hue in the fall, and the ‘Sunburst' Locust (Gleditsia triacanthos var. inermis 'Sunburst') which offers a vivid display of fall color. Unfortunately, it is susceptible to the Invasive Shot-Hole Borer. If you have one of these lovely trees already, take good care of it to help it stand up to this aggressive pest!
Happy Fall! Enjoy the cooler weather, family and friends, and lovely trees!
- Author: Janet Hartin
University of California UC ANR Green Blog (Climate Change and Other Topics) https://ucanr.edu/blogs/Green/index.cfm?tagname=climate%20change (full index)
Examples:
- Save Trees First: Tips to Keep Them Alive Under Drought https://ucanr.edu/b/~CdD
- Landscaping with Fire Exposure in Mind: https://ucanr.edu/b/~G4D
- Cities in California Inland Areas Must Make Street Tree Changes to adapt to Future Climate https://ucanr.edu/b/~oF7
Drought, Climate Change and California Water Management Ted Grantham, UC Cooperative Extension specialist (23 minutes) https://youtu.be/dlimj75Wn9Q
Climate Variability and Change: Trends and Impacts on CA Agriculture Tapan Pathak, UC Cooperative Extension specialist (24 minutes) https://youtu.be/bIHI0yqqQJc
California Institute for Water Resources (links to blogs, talks, podcasts, water experts, etc.) https://ciwr.ucanr.edu/California_Drought_Expertise/
UC ANR Wildfire Resources (publications, videos, etc.) https://ucanr.edu/News/For_the_media/Press_kits/Wildfire/ (main website)
-UC ANR Fire Resources and Information https://ucanr.edu/sites/fire/ (main website)
-Preparing Home Landscaping https://ucanr.edu/sites/fire/Prepare/Landscaping/
UC ANR Free Publications https://anrcatalog.ucanr.edu/ (main website)
- Benefits of Plants to Humans and Urban Ecosystems: https://anrcatalog.ucanr.edu/pdf/8726.pdf
-Keeping Plants Alive Under Drought and Water Restrictions (English version) https://anrcatalog.ucanr.edu/pdf/8553.pdf
(Spanish version) https://anrcatalog.ucanr.edu/pdf/8628.pdf
- Use of Graywater in Urban Landscapes https://anrcatalog.ucanr.edu/pdf/8536.pdf
- Sustainable Landscaping in California https://anrcatalog.ucanr.edu/pdf/8504.pdf
Other (Non-UC) Climate Change Resources
Urban Forests and Climate Change. Urban forests play an important role in climate change mitigation and adaptation. Active stewardship of a community's forestry assets can strengthen local resilience to climate change while creating more sustainable and desirable places to live. https://www.fs.usda.gov/ccrc/topics/urban-forests
Examining the Viability of Planting Trees to Mitigate Climate Change (plausible at the forest level) https://climate.nasa.gov/news/2927/examining-the-viability-of-planting-trees-to-help-mitigate-climate-change/
Reports and other information resources coordinated under the auspices of the United Nations and produced through the collaboration of thousands of international scientists to provide a clear and up to date view of the current state of scientific knowledge relevant to climate change. United Nations Climate Action
Scientific reports, programs, action movements and events related to climate change. National Center for Atmospheric Research (National Science Foundation)
Find useful reports, program information and other documents resulting from federally funded research and development into the behavior of the atmosphere and related physical, biological and social systems. Search and find climate data from prehistory through to an hour ago in the world's largest climate data archive. (Formerly the "Climatic Data Center") National Centers for Environmental Information (NOAA)
Think tank providing information, analysis, policy and solution development for addressing climate change and energy issues (formerly known as the: "Pew Center on Global Climate Change"). Center for Climate & Energy Solutions (C2ES)
Mapping Resilience: A Blueprint for Thriving in the Face of Climate Disaster. The Climate Adaptation Knowledge Exchange (CAKE) was launched in July 2010 and is managed by EcoAdapt, a non-profit with a singular mission: to create a robust future in the face of climate change by bringing together diverse players to reshape planning and management in response to rapid climate change. https://www.cakex.org/documents/mapping-resilience-blueprint-thriving-face-climate-disaster
Cal-Adapt provides a way to explore peer-reviewed data that portrays how climate change might affect California at the state and local level. We make this data available through downloads, visualizations, and the Cal-Adapt API for your research, outreach, and adaptation planning needs. Cal-Adapt is a collaboration between state agency funding programs, university and private sector researchers https://cal-adapt.org/
Find reports, maps, data and other resources produced through a confederation of the research arms of 13 Federal departments and agencies that carry out research and develop and maintain capabilities that support the Nation's response to global change. Global Change (U.S. Global Change Research Program)
The Pacific Institute is a global water think tank that combines science-based thought leadership with active outreach to influence local, national, and international efforts to develop sustainable water policies. https://pacinst.org/our-approach/
Making equity real in climate adaptation and community resilience policies and programs: a guidebook. https://greenlining.org/publications/2019/making-equity-real-in-climate-adaption-and-community-resilience-policies-and-programs-a-guidebook/
Quarterly CA Climate Updates and CA Drought Monitor Maps (updated each Thursday) https://www.drought.gov/documents/quarterly-climate-impacts-and-outlook-western-region-june-2022
- Author: Janet Hartin
What do Fritillaria devlavayi plants and chameleons have in common? Think evolution and ensuring their survival for years to come. If you thought about their ability to camouflage themselves, you're right!
Plants have a will to live similar to humans and other animals. Besides changing colors, some plants have changed their shapes and patterns over many thousands of years to blend in with their environments. What is a newly discovered twist is that researchers in China determined that humans have also influenced the camouflaging of plants. Yang Niu, Martin Stevens, and Hang Sun published a paper in Current Biology on this topic. 
Why? Fritillaria made this adaptation to protect it from extinction by “hunters” whose goal was to harvest it. Rocky areas are more porous and loose, lending themselves to easier plant collection. Fritillaria has no known natural enemies leading researchers to surmise that human harvesting resulted in the camouflaging adaptation.
Photo credit for all pictures: Yang Niu.
Can you find the Corydalis hemidicentra?
This isn't an outrageous claim at all. Humans are known to have exerted strong selection pressure on some animal traits, resulting in unintentional evolutionary changes. Examples include bighorn sheep having smaller horns than they used to, keeping trophy hunters at bay allowing the bighorn sheep to survive. In other research, a group of UC Santa Barbara scientists led by Dr. Scott Hodges, an ecology professor, hypothesized that columbine flower color has evolved in North America as a survival mechanism. While red columbines are pollinated by hummingbirds, white and yellow ones are pollinated by hawkmoths. Over time, this color change occurred five times. In this mutually beneficial arrangement, flora and fauna both stand to gain! Score one for natural selection. See if you can spot the hidden plant (Corydalis hemidicentra).
The next time you're out in nature take a close look around you. You may see something you never noticed before in your own neighborhood or gain a fresh perspective on the wonders of plants and nature.
- Author: Janet Hartin
Fall is a great time to plant trees in our urban landscapes. Temperatures are cooler than summer and trees adjust to transplanting much better than during the heat of summer.
Why trees? Trees reduce surface temperatures of asphalt and other dark impervious surfaces by over 60 degrees F in inland cities during spring and summer. They also reduce energy usage and costs, enhance habitat and pollinator populations, absorb and store carbon dioxide, provide oxygen for our subsistence, reduce erosion, reduce glare and noise, add beauty to our neighborhoods, and enhance mental and emotional health.
I am appreciative to UCCE San Bernardino County Master Gardener trainee Alex Shippee for his graphic design wizardry, making a drab publication on planting trees inviting and appealing to read.
Have more questions about your trees? Contact the UC Cooperative Extension Master Gardener tree helpline in San Bernardino County. 22trees4tomorrow@gmail.com or our general telephone helpline at (909)387-2182 or email mgsanbern@ucanr.edu where your gardening questions can also be addressed. (You will also reach this website by following the QR code link above.) We also have this handout available in Spanish.
