Right Tree, Right Place

Trees are often pointed to as a panacea for climate change, the most cost-effective environmental engineering we can do to cool the planet. The t-shirt slogan/ ancient Chinese proverb is inescapable: "The best time to plant a tree was 20 years ago. The second best time is now." However, my time following grasslands scientists on Twitter, back when it was a useful tool for networking and research, made me look more skeptically at trees. See my blog post from 2019 with more links about the relative importance of grasslands and kelp forests as carbon sinks. I still chuckle at the quip by one scientist: "Trees are dorks who put loads of their carbon aboveground." 

Mount Diablo sunset, photo credit: me

Besides being prone to burning and unhelpfully releasing lots of carbon dioxide into the atmosphere, trees can be a problem because you can't just plant any tree anywhere, and people don't always take the time to think ahead. A July 2025 Guardian UK article "How a £1.5bn ‘wildlife-boosting’ bypass became an environmental disaster" describes just such an instance, where a biodiversity corridor along an English highway instead turned into a dead zone, where nearly all the tree saplings died: "they had planted the wrong species in the wrong place." National Highways, the supervising agency, had to admit nature was left worse-off after the project, with the death of nearly all of the 860,000 trees they planted.

Meanwhile, I spent most of the last five years working on wildfire mitigation in California, where the slogan "right tree, right place" is repeated by all the players (government, utilities). In particular, the utilities want you to think ahead before planting a tree: sometimes they get left holding the bag when someone's poorly placed or poorly maintained tree comes into contact with bare wire and there's an ignition. All three major investor-owned electrical utilities in California have repositories of information on how to select the right tree and place it at a safe distance from electrical infrastructure.

 

Seen in a friend's garden, photo credit: me

Here are some tree planting planning resources the utilities point to:

• CalPoly's SelecTree Tool (which includes a filter for California native plants and "has fall color")
• The Arbor Day Foundation's Tree Wizard Tool

And then there are the utility-specific pages:

• PG&E "Planting Safely" (scroll down to Safe Planting Resources)
• SCE "Power Lines and Trees" (and the two-page 2019 brochure "Right Tree, Right Place") 
• SDG&E "Plant the right tree in the right place"

Some other resources you might want to reference:

• The California Native Plant Society's Calscape Search Page - to locate native trees and shrubs to suit your needs
• The National Cooperative Soil Survey's Web Soil Survey - to learn about your soil's characteristics

On a related note, researchers published a study in Nature Communications last year (2024) looking at where global warming from reducing surface reflectivity (albedo) from increasing tree canopy can partially or even completely counteract the cooling benefit of increased carbon storage in trees. It turns out "[i]n most locations, these changes in albedo offset or even negate the carbon removal benefits" (Hasler et al. 2024 "Accounting for albedo change to identify climate-positive tree cover restoration").

The researchers produced a spatial data set for land managers to help them determine how much the decreased reflectivity from additional tree cover might impact the carbon removal benefit of a reforestation project. Without taking the reflectivity reduction impact into account, land managers might be overestimating the carbon removal benefit of reforestation projects "anywhere from 20 to 81%" (as described in the Nature Conservancy summary of the study "New maps help decision-makers factor albedo into tree-planting strategies").

If you don't have an easy way to use a spatial data set, you can estimate a reforestation project's impact using the Nature Conservancy's Naturebase mapping tool, which "integrates albedo into both its reforestation and avoided forest conversion estimates."

My backyard Bradford Pear tree, photo credit: me

Remember - trees are dorks! They burn and they absorb sunlight which both warm the planet. Plant them strategically! 

Dispatch from Western Australia- Lessons for California

Mark Lubell, an Associate Professor at the Dept. of Environmental Science and Policy at UC Davis, is visiting Western Australia and writing on his department's blog about that country's water management lessons for California. Read his latest post: "Dispatch: Climate Adaptation in Southern California...oops...I mean Perth, Western Australia."

According to his departmental bio, Mark studies human behavior and the role of governance institutions in solving collective action problems and facilitating cooperation. His bottom line in this latest post:

Australia appears to have a far more centralized set of environmental management institutions than California, with centralization at the level of state agencies. This is a nuanced statement because in another way natural resource management is decentralized like in California--the national government gives all the responsibility to the states (for example, the states manage the national parks). But in terms of regional adaptation, the state agencies have a lot of centralized control. The chief example is the Water Corporation, which manages all of the water infrastructure and delivers water to households. The local governments don't provide the water themselves, and in fact the local governments have far less control over their resources than cities and counties in the US. So the number of actors and policy games involved with climate adaptation is smaller and more centralized in [Western Australia], which makes for an interesting comparison and possibly a better ability to actually get things done.

I wonder-- what conditions could lead to the creation of a state "Water Corporation" like this in California? Would people cede control at the prospect of trucking in bottled water in a severe drought? Adelaide, Australia, faced this prospect in 2009.

I also wonder how the Australian Water Corporation handles water rates, and if they have anything like a "universal lifeline" rate for low-income households to provide the poor access to water in a drought. It appears from the Water Corporation's website that seniors and pensioners can get "a substantial rebate or concession" on their water bills. Otherwise, it seems water users can negotiate a payment plan, but not for a reduced rate.

Some utility districts in California offer a low-income water rate, but from what I know most don't. Again, I wonder what it would take for California to mandate a water rate for the poor.

--- An aside:

The idea of a universal lifeline rate for water isn't my own idea, incidentally. The Pacific Institute's Peter Gleick, speaking at a UNESCO conference in 1998:

Water is a social good-- we all agree on that. People should pay for its use, to encourage efficiency and as a recognition of its value. But perhaps a universal 'lifeline rate' should be established, and anything above that should be priced much higher. To water a lawn, for example, should be truly expensive.

(As quoted in Water: The Fate of Our Most Precious Resource by Marq De Villiers, 2001.)