Posts Tagged: urban heat islands

Climate change resources for Horticulturists, Government Officials, and UCCE Master Gardeners

Climate Change Resources for Horticulturists and UCCE Master Gardeners

Updated by Janet Hartin jshartin@ucanr.edu 8/17/2022

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

UC Climate Change Videos                                 

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)

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 UC (Non-ANR) scientists

Daniel Swain (UCLA): website: https://weatherwest.com/ twitter: @Weather_West

 

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

 

 

 

Master Gardener Spotlight: Redlands Tree Canopy Enhancement Team

It's only right that our University of California Cooperative Extension (UCCE) San Bernardino County Master Gardener ‘Trees for Tomorrow' team of volunteers are our featured ‘Spotlight' Master Gardener volunteers for September, 2021. They provided vital education to Redlands residents receiving gratis trees through a multi-partnership grant obtained by Inland Empire Resource Conservation District Manager Mandy Parkes. 

It's an honor and privilege to recognize UCCE San Bernardino County Master Gardener Project Leader Debbie LeDoux and her dedicated team of 'Trees for Tomorrow' volunteers: Zhibo (Sandy) Anderson; Consuelo (Connie) Davis (pictured); Pam O'Connell; Gail Sefl; and Husam Yousef. These dedicated Master Gardeners were tasked with helping residents select, plant and care for drought, heat, and pest tolerant trees. (Species including Chilopsis linearis 'Bubba', and Pistacia x 'Red Push' were selected due to their excellent performance in our University of California/United States Forest Service research project as 'climate-ready' trees able to withstand harsh conditions related to our changing climate.) Working with a team of California Climate Action Corps volunteers, civic leaders, Common Vision Coalition, and other groups, nearly 100 trees were planted in yards and parks lacking the preferred 25% tree canopy cover.

Trees can cool urban heat islands by 50 degrees Fahrenheit or more during spring and summer, creating welcome oases in hot inland communities. With spring 2021 temperatures so high they broke previous records on multiple dates, the project is especially timely and necessary.

In addition to proper tree selection, trees require the right long-term care. Master Gardeners will continue to provide advice on irrigation, pruning, fertilizing and pest control to residents receiving trees long after the trees are planted. This is critical since an average urban tree lives less than 20% of its potential lifespan due largely to poor care. The long-term engagement of Master Gardeners with residents is as important as is selecting the right species.

UCCE Master Gardeners are all volunteers, giving of their time and talents to enhance the quality of life for individuals and families who call San Bernardino County their home. Each Master Gardener is required to complete a rigorous 18-week training class complete with exams, class projects, and lots of participation! Due to COVID-19, volunteers had to master key horticultural concepts during the first ever all on-line training class. Only recently have they been able to meet fellow Master Gardener graduates and, in some cases, the Redlands residents they mentored through the tree canopy enhancement project. They truly exemplify community spirit and all it takes to successfully work together under adverse conditions. Kudos to each and every one of you from Master Gardener Coordinator Maggie O'Neil and myself! You are creating a cooler, greener and healthier environment for our children's children.  

 

I asked the honored Master Gardeners their thoughts on the project. Here's what they had to say:

“The Redlands tree canopy project was the best volunteer project ever. In the midst of Covid-19, horrific politics and way too many good byes, it was a truly joyous experience. The legacy of being a part of the group that promoted healthy sustainable trees, knowledge of how to plant and care for them, tips on maintaining their health and beauty was the absolute best. For me as a Master Gardener, it was so much fun. I loved the site walks and getting to help our participants select the perfect sustainable trees for their properties. What started as a one-on-one visit often expanded to an enlarged group of neighbors and extended family. I got to give out many handouts and publications and promote our excellent Master Gardener program. I got to share our helpline email and phone numbers. I love the fact that I have been asked to revisit sites to see how great they are doing (once to make sure the tree did not look funny!). I receive emails every now and then asking me questions and showing me pictures of "Our Trees.” So much fun, Janet. Thank you. By far the coolest project ever! Pam O'Connell

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There are a few things that really made an impact on me.

 

1) It was rewarding to attend the Zoom presentation you developed that provided education to various professionals on the importance of planting sustainable trees. I found it to be open and inclusive allowing for good interchange of ideas and concerns. 

2) There are many beautiful trees that are sustainable.

3) Reaching out to the community to offer beautiful, sustainable trees was a worthwhile way to show how various organizations can work together to benefit the community while trying to improve our environment.

4) When dealing with homeowners that belong to an HOA, additional time and communication may be needed to assist them in obtaining approval for trees from their HOA's. Connie Davis

 

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"I see tree planting efforts similar to what a trend of the future is to combat climate change and increase awareness of the importance of trees and tree canopies in our neighborhoods. Not only that but I see this project expanded to other cities in the county of San Bernardino. The continuity of this project is so valuable so that we can see the positive impact on the environment and the well-being of San Bernardino residents in the coming decades. I see this important work being organized and well-coordinated by involving the appropriate stakeholders at all stages of the planning project. It is about time to give back what we have taken for tens of years!" Husam Yousef 

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It was rewarding to see local homeowners excited about planting trees and grateful for the program providing them. Gail Sefl

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THANK YOU ALL!   Janet Hartin and Maggie O'Neill

Synthetic turf, dark mulch and asphalt surfaces are superheating our inland cities

an plants help cool our urban heat islands and mitigate impacts of climate change in our inland cities? I've been interested in measuring the temperatures of living and non-living surfaces for some time. Preliminary results are in! Use of dark asphalt, synthetic turf,

and dark colored mulches are superheating our inland and desert cities. The hottest material of the three is synthetic turf which reached over 165 degrees F in Palm Springs and 159 degrees F in Redlands on days when the  air temperatures were, respectively, 113 and 108 degrees F this summer. On five separate days in July, seconds after I took a quick photo above the artificial turf, my I-phone shut down, leaving me with the ominous heat warning message shown here (lower right).

What can you do?

Take care of your trees, shrubs, groundcovers, and lawns to maximize their ability to cool the surrounding environment. In the same experiment described above, the coolest temperatures occurred in lawns growing in the shade of a mature tree. This is due to living plants cooling the environment during the process of transpiration. Non-living surfaces don't provide this natural air-conditioning. While many people believe lawns waste water, it's important to fully consider the alternative of replacing a water-efficient warm-season lawn like Bermuda or Buffalograss with either dark mulch or no living plants at all.  The lawns are much cooler! Our previous UC studies determined that it's often not the lawns (and other sprinkler-irrigated plants like groundcovers) that waste the water, it's the uneven coverage (low distribution uniformity) of most sprinkler systems, coupled with not applying the right amount of water seasonally. 

However, If you're tired of your high maintenance lawn and want to ditch your lawnmower, fertilizers, and pesticides, consider a low-maintenance drought-resistant groundcover that has similar cooling effects without the need for chemical inputs.

Plant drought-tolerant groundcovers

Here are just a few examples: 

Peruvian Verbena (Verbena peruviana). This groundcover grows to only 1" tall  and sports dark green leaves and white to pinkish (several hybrids available) blossoms that bloom from spring through fall. It spreads quickly and requires little water once established.

Dwarf Rosemary (Rosmarinus prostratus) This particular rosemary species is a low-growing groundcover.  It is a great choice for rock gardens, reaching only 6 inches tall. It produces purple flowers in the summer and attracts pollinators and can be used for culinary purposes (bottom). 

Gold Dalea (Dalea capitata). This semi-deciduous evergreen grows between 8" to 1' tall and has small yellow flowers that bloom in spring and fall and a pleasant scent. It is very heat tolerant and great for urban heat islands (parking lots, etc.) as well as planters and paths (lower right).

For more information on trees, groundcovers, shrubs, and vines suitable for your own home, contact a UC Cooperative Extension Master Gardener volunteer in your county using this link: https://mg.ucanr.edu/FindUs/

Tips to Keep Your Landscape Plants Alive During Drought

In your landscape, your trees and edibles should come first under drought and water restrictions! If there just isn't enough water to go around, your lawn and flowers should be sacrificed instead. Trees are our most valuable landscape resource and take years to maximize their benefits (shade, cooling, habitat/ecosystem enhancement, carbon dioxide storage, energy conservation, pollution filters, etc.).

Just a few slow, deep waterings with a garden hose away from the trunk and slightly beyond the drip line will keep established trees alive, even during summer.  Remember to keep trunks dry!

Here are some other tips:

• Spread and maintain 2-4” of mulch around garden plants and trees (3-4” for wood chips, 2” for pebbles, decomposed gravel, etc.) keeping it a few inches away from tree trunks. (Note: dark colored dyed mulches should be avoided in inland and desert areas due to their high surface temperatures that can > 60 degrees F hotter than living plants and lighter colored mulches.) 

• Water early in the morning when soil evaporation is minimal.

• Control weeds. They compete with other plants for water.

• Avoid fertilizing. Nitrogen increases growth and the need for more water.

• Don't plant new plants during the summer when temperatures are highest. Even drought-resistant native and non-native plants need regular watering their first season.

 

Plant a Tree. Leave a Legacy!

Do you have Spring Fever? If you have adequate space, why not leave a legacy to your children's children by planting a tree? When the right species is planted in the right location with the right care, landscape trees can be enjoyed for 100 years or more. Landscape trees cool urban heat islands, absorb carbon dioxide, filter toxic chemicals from soil preventing them from polluting our waterways, reduce soil and water erosion, reduce internal energy needs and related costs, provide habitat, and beautify neighborhoods.

Spring is a much better times to plant a container landscape tree in California than is summer. Trees incur far less stress if they've been in the ground several weeks rather than having to immediately adapt to high summer temperatures. Cooler weather allows plants to establish roots in their new ‘home' before the harshness of summer sets in. (Deciduous bare-root fruit trees, on the other hand, should be planted during the winter when they are dormant.) Choose recommended species for your climate and micro-climate.

Choose trees based on your Sunset climate zone (more precise than USDA zones for California since they include impacts of high temperatures as well as low temperatures) and your microclimate (shade, soil conditions, space, etc.). Four of my favorite search engines that allow one to search by multiple criteria (size, water needs, flower color, ecosystem functions, pest susceptibility, etc.) are: Inland Valley Garden Planner: https://inlandvalleygardenplanner.org/; Cal Poly, Pomona: https://selectree.calpoly.edu;California Native Plant Society: http://www.cnps.org/cnps/grownative/lists.php; and WUCOLS IV (Water Use Classification of Landscape Species): http://ucanr.edu/sites/WUCOLS

Avoid circled, girdled roots. Remember to inspect the root system of container trees. Avoid purchasing specimens with severely circled and girdled roots. Root pruning will not solve the problem and the resulting tree is much more prone to failure later. This occurs because the upper portion of the tree continues to grow and expand while the root system lacks the breadth and architectural strength to support the tree. Many times a tree will look fine for several years and - seemingly - very suddenly topple in winds that otherwise it could sustain with a more adequate root system. Only when the tree falls does the owner actually notice firsthand that the root system is the same size it was when the tree was planted years before!

Check drainage before you plant. Dig a hole where you are planning on planting the tree, fill it with water, and make sure it completely drains within 24-hours. If it doesn't drain, don't plant a tree there. In some cases, trees are carefully selected based on species and location only to perish ten or more years later due to poor drainage and water-logged soil. Trees often die in these situations due to a lack of aeration setting them up for disease-causing fungal pathogens.

Planting the tree. Dig a hole at least 2-1/2 times the width of the container (in clay or compacted soils make the hole at least 4-5 times wider) up to two inches shallower than the depth of the tree in the container to compensate for settling. Use a shovel or trowel to roughen the soil on the sides of the hole to encourage root growth into the native soil. Remove the tree from the container along with any loose soil that covers the lower part of the trunk. Carefully place the tree in the planting hole, keeping the trunk flare (the area where the trunk widens and connects with the roots) 1-2 inches above the existing grade. Gently fill the hole with the same soil that was removed. Do not add soil amendments or compost, another common cause of circled and kinked roots. Irrigate the tree immediately after planting through the entire root system and slightly deeper. Keep in mind that soils with appreciable clay content absorb water more slowly than sandier soils and need to be watered longer but less often. Water newly planted container trees often through their establishment period, even if they are drought tolerant species. Recently transplanted trees have a small volume of roots that dry out very quickly. Water newly planted trees regularly through the first season. Trees in sandy soils require more frequent watering than do trees in heavier soils. (After trees are fully established, irrigation frequency should be reduced but more water should be added during each irrigation.)

Avoid staking trees unless necessary. Stake trees only if they were staked at the nursery and/or if they are planted in a wind-prone area. Remember to loosen ties on nursery stock before they girdle the trunk. Gently secure any tree requiring staking with two opposing flexible ties on the lower half of the tree, allowing the tree to gently blow in the wind to encourage lower trunk strength. Avoids taking trees tightly, restricting flex. As the tree matures, remember to loosen ties and aim for removing stakes entirely if the tree is self-supporting.

Pruning. Avoid heavy pruning at the time of planting. Remove only broken branches, crossed branches and suckers at the base of the tree.

Fertilizing. Most trees have received adequate nutrition in the nursery and do not need fertilizer at the time of planting.

Mulching. Apply a 2-4 inch layer of mulch three or more inches away from the tree trunk. Organic mulches such as woodchips and compost should be applied and maintained at a depth of 3-4 inches to prevent weed seeds from sprouting. Inorganic mulches (gravel, pebbles, etc.) should be maintained at 2-3 inches. In fire-prone areas, organic mulches near the urban/forest interface should be avoided. Remember to irrigate below the mulch.

For more information on tree planting and care and all other home gardening and landscape topics, contact the UCCE San Bernardino County Master Gardener Helpline at mgsanbern@ucanr.edu

 

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