This is a blog about the native conifers of the Pacific Northwest. It is a companion to the Northwest Conifers site. The blog will focus on timely and interesting details about our conifers, their connections to the rest of the environment, and our connection to them.

Thursday, November 17, 2016

Dorena Genetic Resource Center Visit

In October, Martin Nicholson, Curator at Hoyt Arboretum, took a group of us on a day trip to the Dorena Genetic Resource Center a few miles south of Eugene. The Dorena Center is a US Forest Service facility that does genetic research to find disease resistant conifers, focusing on white pine and Port Orford cedar. Seedlings grown at the Center are planted in seed orchards to produce large numbers of seeds, which can be used for reforestation and restoration. We met Richard Sniezko (Center Geneticist and Acting Manager), who gave us a tour of the facility at Dorena and the BLM's Tyrrell Seed Orchard, located southwest of Eugene in the Coast Range.

White pines growing at the Dorena Genetic Resource Center

White pine blister rust 

White pine blister rust
The primary focus of the Center is white pine blister rust (scientific name Cronartium ribicola). This pathogen is an invasive fungus that attacks five-needle pines, often with deadly results. In the Pacific Northwest, these pines include western white pine (Pinus monticola), sugar pine (Pinus lambertiana), and whitebark pine (Pinus albicaulis). Whitebark pine in particular has been devastated by white pine blister rust. 

To begin research on finding resistant pines, researchers gather seeds from various locations and grow seedlings. To expose the seedlings to the white pine blister rust, researchers gather infected leaves of shrubs like currants and gooseberries. The rust requires two host species to complete its life cycle. One is a species of white pine. The other can be a variety of plants, locally, usually shrubs like currants and gooseberries. The infected shrubs infect the trees, and the trees in turn infect more shrubs. The seedlings at Dorena are infected or "inoculated," as Richard Sniezko put it, by placing them in a large room under a screen that holds the infected leaves of the shrubs. Artificial fog is piped into the room, where water collects on the leaves and drips onto the white pine seedlings, carrying the rust spores with it.

Whitebark pines tested for resistance to blister rust.
Some survive,  others, not so much.
The inoculated seedlings now can be grown to see which ones are rust resistant. Genetically similar seedlings (called a family) are arrayed in a row, with other families in other rows. After a few years, the differences between families is striking, with some surviving and others completely dead.

Once rust-resistant specimens are identified, they can be grown for seed to be used for restoration and reforestation. To meet the demand for seed, resistant trees are grown at the Tyrrell Seed Orchard, and other seed orchards in the Pacific Northwest.

Note that the center develops diverse families of resistant seed.  This is important for two reasons: (1) It enables foresters to restore the new seedlings to habitats to which they are adapted. This enhances their ability to thrive in that environment. (2) It maintains genetic diversity among the planted trees. This enables them to adapt more readily to future changes and survive other diseases.

White pines at the BLM's Tyrrell Seed Orchard
Whitebark pine has been devastated by white pine blister rust in many areas, including the Cascade Mountains. You can see how the Dorena Center has been helping with restoring whitebark pine at Crater Lake in this Oregon Field Guide video. Since the filming, new plantings of rust-resistant whitebark pines have been planted at several locations around the rim of Crater Lake, including one planting near Crater Lake Lodge. Also, see this OPB report on whitebark pine, and another Oregon Field Guide video on the Tyrrell Seed Orchard

It is noteworthy that most of the whitebark pine in the Northwest is located in wilderness. The legal definition of wilderness in the 1964 Wilderness Act expresses the idea that wilderness is to be a place where natural processes are allowed to run their course without human interference. This would seem to preclude planting resistant pines in wilderness. However, in the case of white pine blister rust, it has been human interference that introduced the pathogen into the wilderness. US Forest Service regulations now allow forest restoration in wilderness when we can't reasonably expect that the forest can recover naturally. However, in some cases, it makes sense to leave recovery to natural processes and learn from what happens naturally.

Cedar root disease

The Dorena Genetic Resource Center also works with Oregon State University to research and grow Port Orford cedar (Chamaecyparis lawsoniana) that is resistant to cedar root disease. This pathogen (Phytophthora lateralisis an introduced fungus-like water mold that is related to brown algae. It was first reported in the United States on ornamental Port Orford cedar seedlings near Seattle in 1923. By 1952, it had spread to the natural range of Port Orford cedar near Coos Bay, Oregon. Since then, it has spread throughout the range of Port Orford cedar in southwest Oregon and northern California, killing large numbers of trees. It has also attacked cultivars of Port Orford Cedar, adversely affecting the horticulture industry.  It also can kill Pacific yew (Taxus brevifolia) growing near infected cedars. Western red cedar (Thuja plicata) is resistant to the disease but can be infected. 

Pine and cedar seedlings
Researchers have located Port Orford cedars growing in the wild that are apparently resistant to cedar root disease and have used these for a program to grow seeds of resistant trees. One approach is to grow small trees for seed in a greenhouse at the Center. The trees are treated with gibberellic acid, a hormone that stimulates them to produce cones at an early age. This quickly provides seeds to grow resistant seedlings.

Diverse plantings of Port Orford cedars are also growing at the Tyrrell Seed Orchard to provide resistant seed for planting. As with the pines, it is important to maintain genetic diversity in forest habitats and to plant new seedlings in habitats to which they are adapted.

Port Orford cedar at the Tyrrell Seed Orchard 
One possible monkey wrench in the program of developing disease resistant trees is that the pathogens that attack them can also undergo genetic changes so that they are lethal to the resistant trees. This could mean job security for geneticists fighting the diseases. It's likely to be a continuing battle. 

Sources and more info

Sunday, November 6, 2016

Conifer Cultivars

A recent trip to the Oregon Garden was a great opportunity to see a great variety of conifer cultivars. Many of the conifers you find in landscaping are cultivars of naturally growing species. What is a cultivar? "Cultivar" is a short version of "cultivated variety." It is a plant selected for some set of desirable characteristics, often a result of careful breeding to accentuate those characteristics. Most garden plants and food crops are cultivars.

There are only about 600 species of naturally growing conifers. However conifer cultivars number in the thousands. The Encyclopedia of Conifers describes over 8000 cultivars. The authors note that there may be over 15,000 conifer cultivars now.
Dwarf cultivars - All photos from the Oregon Garden
Cultivar names: The formal names of cultivars are formed by adding a special name to the Latin name of the species. These names can be in any language and are enclosed in single quotations marks, for example: Picea glauca 'Pendula', a cultivar of white spruce. Cultivars often have common names as well, in this case, weeping white spruce.
Picea glauca 'Pendula'

Variability: Cultivars can look entirely different from their parent species. Like the variety of dogs "cultivated" from the wolf, there may be hundreds of different cultivars developed from a single species of conifer. Over 450 have been produced from one Oregon native: Port Orford cedar (Chamaecyparis lawsoniana). Western red cedar has produced over 40 cultivars.

Origin: Many cultivars originated from naturally occurring genetic variations in a species or from genetic mutations. Others are produced by bud mutations on a normal tree. These can result in color change, different growth patterns, or dwarfing. Bud mutations often produce witches' brooms, a reduced growth form that creates a mass of short branches that often look like a dense bush growing high in a tree.

Cultivars are often reproduced by cloning, for example by growing cuttings taken from a twig. Some are reproduced from seeds, but normal reproduction introduces genetic variability that is often difficult to control.
Cupressus glabra 'Raywood's Weeping'
- a cultivar of Arizona cypress

Features: Conifers often grow to be large trees, not suitable to a small landscaped yard or garden. Many conifer cultivars are dwarfs compared to their parent species. They have been selected because they grow slowly and remain a reasonable small size for years. Many are selected for their unusual color, often showing blue or variegated leaves. Some show unusual growth patterns that people find attractive. A favorite feature is stringy, drooping branches. These cultivars are often named 'Pendula' or 'Weeping'.

One of the best places to see conifer cultivars is at the Oregon Garden. The Conifer Garden there features an extraordinary variety of cultivars that are beautifully landscaped and maintained. Fall and winter is a great time to visit. The conifers look about the same as in spring and summer, and you will avoid the crowds of people. 

Sequoiadendron giganteum 'Pendula'
 - a cultivar of giant sequoia

Abies koreana 'Silberlocke' - a cultivar of Korean fir

Abies koreana 'Piccolo' -  a cultivar of Korean fir

Cedrus atlantica 'Glauca Pendula' - Stretches across the photo and over the trellis
More info
Encyclopedia of Conifers [Caution: Extremely heavy. Lift with legs, not back.]
Bert Cregg: Extension Publications and Conifer Corner articles 

Monday, October 3, 2016

Bristlecone Pines: The Oldest Living Tree

On our recent trip to California, my wife and I drove up to Schulman Grove in the White Mountains to see the ancient bristlecone pines. Specimens of the Great Basin bristlecone pine (Pinus longaeva), are the oldest living trees in the world. These bristlecone pines have needles that grow in bundles of five. The needles are short for a pine, only about one inch long and spread along the branch like a bottle brush. However, these short needles live a long time, lasting up to 43 years. The cones are about three inches long. The growth form is often contorted and gnarled. Old trees have colorful, exposed wood that has lost its bark. Great Basin bristlecone pines grow at elevations over 10,000 feet in the White Mountains of California, and to the east in the mountains of Nevada and Utah. 

In 1953, Edmund Schulman discovered the world's first known 4000-year-old tree in the grove of bristlecone pines now called Schulman Grove. He used an increment borer to get samples of the growth rings of many of the bristlecone pines in the area and discovered one that was over 4700 years old. The oldest known living tree is another bristlecone pine that is over 5000 years old (5060 years old in 2012). It is growing at an undisclosed location, about 12 miles north of Schulman Grove.

Schulman Grove is located 24 miles from Big Pine, California. The road to get there is paved, but steep and winding. There is parking at the Ancient Bristlecone Pine Forest Visitor Center, where you can hike three trails at Schulman Grove. There is no water to be had in lake, stream, spring, or well, which tells you something about the arid nature of the White Mountains, and should suggest something about the nature of the bathroom facilities located near the Visitor Center. I hiked around the mile long Discovery Trail loop to get the photos shown here.

Tree-ring dating
It's easy to determine the age of a tree by counting the annual growth rings after it has been cut down. A less destructive way is to use an increment borer. This device is a long hollow drill bit that can extract a thin cross section of a tree, which enables you to count the tree rings. Also, since the rings are wider in wet years, you can determine variable weather patterns throughout the history of a tree. Furthermore, this variability forms patterns that researchers can recognize in different core samples. By comparing cores from living trees with cores from dead trees and wood fragments, researchers can extend their knowledge of weather patterns back for thousands of years. We now have a continuous record of bristlecone pine tree rings going back over 11,000 years. Also, tree rings in the wood at archaeological sites enable scientists to determine the age of the wood.

Since the tree rings provide an accurate count of the years, this research has enabled scientists to calibrate the readings from radiocarbon dating, giving archaeologists all over the world more accurate data on the age of artifacts.

Sunday, March 20, 2016

Gray Pine

I was at the Portland Chapter meeting of the Native Plant Society recently and someone there told me that the gray pine (Pinus sabiniana) was an Oregon native. This was news to me. It’s not listed in Trees to Know in Oregon, from the Oregon State University Extension Service. Also, Ronald Lanner writes in Conifers of California that gray pine is “…a native to California alone – without any Nevada or Oregon outliers.” (p. 71) He goes on to quote David Douglas on the discovery of the gray pine: “I have added a most interesting species to the genus Pinus, P. sabinii, one which I had first discovered in 1826, and lost, together with the rough notes, in crossing a rapid stream.” However, David Douglas was not in California in 1826. He was in the Umpqua Valley area of Oregon in search of sugar pine, where he must have also seen some gray pine. The “rapid stream” he crossed was the Santiam River.

Frank Callahan documents the discovery of the gray pine in Oregon. He reports that a railroad survey in 1855 recorded them growing in Jackson County between Gold Hill and Central Point. In 1945, Oliver Matthews provided the first scientific documentation of Pinus sabiniana in Oregon after collecting specimens near Gold Hill. Callahan notes numerous specimens that he has located in the Medford area.  (See Frank Callahan, “Discovering Gray Pine (Pinus sabiniana) in Oregon,” Kalmiopsis Volume 16, 2009.

The gray pine is a distinctive pine with long, gray-green needles. Its most distinctive feature is the size of its large, heavy cones. They are usually visible it the top branches of the tree, where they remain for several years after they mature. The cones have the largest seeds of any conifer in the Pacific Northwest. The nutritional seeds were harvested by Native Americans, although too few trees grew in Oregon for them to be an important food source. Since the seeds are too large to be dispersed far from the tree, the gray pine relies on birds to disperse the seeds. Gray pine seeds are a favorite food of the Steller’s jay and scrub jay, which store seeds in the ground to eat later. Since the jays never recover all the seeds, they also plant the next generation of gray pines.

For more information, see Northwest Conifers.

Thursday, February 4, 2016

Focus on Pines

Western White Pine
Pine are the most common conifer in the world, spreading across the land masses of the Northern Hemisphere, including much of North America, Europe, and Asia. The genus of the pines, Pinus, includes over 100 species, more than any other conifer genus. (Aljos Farjon lists 113 species of pine in A Handbook of the World’s Conifers.) Pinus is classical Latin for the Mediterranean stone pine.

Pines have an ancient origin, appearing 130 million years ago. They are older than the firs, spruces, larches, hemlocks, and Douglas firs. All these conifers branched off from ancient pines. Some pine trees are ancient. They can live to be thousands of years old. The oldest living tree is a bristlecone pine that is over 5000 years old, growing in the White Mountains of California.

Northwest Pines

Eight species of pine grow in the Pacific Northwest. Pines don't compete as well in the climate west of the Cascades summit, where forests are dark, damp, and dense. You will find them high in the mountains east of the Cascades summit. Pines are not shade-tolerant and compete best in drier areas where the forests are more open. In a favorable environment many Northwest pines grow to an impressive size, especially sugar pine. Pines can also thrive in poor soils where other trees cannot compete. In extreme environments like cold, wind-swept ridges and the windy Pacific Coast, the pines are often small and contorted. 

Ponderosa Pine

Many pines have an interesting relationship with fire. Since they are not shade-tolerant, they often depend on fire to clear the forest of competing trees before the pine seedlings can sprout and grow. Some species depend on frequent fires. Ponderosa pine depends on low-intensity fires that burn competing species every few years. The thick bark on the ponderosa protects it from the fire, but the fire burns the competing firs. Other pines depend on hotter fires that consume the forest. The cones of knobcone pine and some lodgepole pine remain closed on the tree until they are heated during a fire. After the fire, the cones open and drop their seeds, which germinate and grow to become the next generation of pines.

Whitebark Pine
Other pines take advantage of extreme environments or mutually beneficial relationships with animals. Whitebark pine has adapted to the extreme cold and snowy environment near the timberline. It has also developed a close relationship with the Clark’s nutcracker. This pine holds its seeds in closed cones, waiting not for a fire, but for a Clark’s nutcracker to come and pry out the large, edible seeds. The nutcrackers typically fly off and bury the seeds, which they dig up and eat during the winter. But the seeds that they forget about can germinate and sprout new little whitebark pines. This adaptation of producing large edible seeds is a common tactic used by several species of pines, often called “stone pines.” Birds are not the only animals to benefit. Pine seeds are a traditional food for people, too. If you have extra money to burn, you can buy them today in nearly any grocery, where they are sold as “pine nuts.”

Although ponderosa pine thrives in the dry areas east of the Cascades, it is also native to the Willamette Valley, where it has adapted to the wet environment, and competes well with Douglas fir. Lodgepole pine mostly grows in the Cascades and Rocky Mountains, but it also grows along the Pacific Coast, where it is called “shore pine.” It has adapted to the wet, salty environment along the beach and in nearby bogs.


Limber Pine Cultivar
"Vanderwolf's Pyramid" 
Pines arean important timber resource throughout the world. They are grown in plantations in the south of the U. S. and various locations around the world, including New Zealand and Brazil. The wood is used for construction, woodworking, window frames, and furniture. Pine is a favorite wood for paneling. Pines are a primary source of pulp for paper making. They are also a source for making turpentine.

Pines are widely planted as ornamentals, a tribute to their beauty, but perhaps also because they are often slow-growing. Stately ponderosa pine is a favorite. Its golden bark adorns parks throughout the West. Pines seem to lend themselves to the development of a wide variety of cultivars of different size, shape, and color. The Encyclopedia of Conifers includes 360 pages of pine cultivars.

Identification of Northwest Pines

It’s easy to distinguish pines from other conifers. Pine needles typically grow in bundles of two, three, or five. Unlike the thin scales on hemlock and spruce cones, pine cones have thick, woody scales. The cones are the largest you will find in the Northwest. You can usually identify a pine species by the number of needles in each bundle or the shape and size of the cones.

Lodgepole PinePinus contorta
Needles: 2 per bundle. Cones: 2” long, egg shaped.
Western white pinePinus monticola
Needles: 5 per bundle, 2-4” long. Cones: 6-10” long, curved.
Whitebark pinePinus albicaulis
Needles: 5 per bundle, 2-3” long. Cones: 2-3” long, closed when mature.
Ponderosa pinePinus ponderosa
Needles: 3 per bundle, 5-10” long. Cones: 3-6” long, egg shaped.
Jeffrey pine Pinus jeffreyi
Needles: 3 per bundle, 5-10” long. Cones: 6-10” long. SW Oregon.
Knobcone pinePinus attenuata
Needles: 3 per bundle, 3-6” long. Cones: 3-6” long. SW Oregon.
Sugar pinePinus lambertiana
Needles: 5 per bundle, 2-4” long. Cones: Large, 10-20” long. SW Oregon.
Limber pinePinus flexilis
Needles: 5 per bundle, 2-3” long. Cones: 3-7” long, open when mature. This pine is rare in the Northwest, growing only in the Wallowa Mountains.


The Gymnosperm Database – Pinus

The Encyclopedia of Conifers by Aris G. Auders and Derek P. Spicer, Vol. 2

A Handbook of the World’s Conifers by Aljos Farjon, Vol 2

Conifers of the World by James E. Eckenwalder

The Wood Database – Pine Wood

Monday, January 18, 2016

Focus on Firs

Grand Fir
Firs (scientific name, Abies) are widespread throughout mountainous regions of the Northern Hemisphere. The genus includes over 40 species. The exact number depends on the source you look at. Four species and two hybrids are native to the Pacific Northwest.

It’s easy to distinguish the firs from other conifers in the Northwest. We can rule out the cedars with their flat leaves and the pines, which have long needles that grow in bundles. Now we just need to eliminate the spruces, hemlocks, larches, and Douglas fir (not a true fir, being in the genus Pseudotsuga.) 

Pacific Silver Fir Cones
You may be able to identify a fir by looking for the cones. The barrel-shaped cones are unique in two ways. First, they stand upright near the top of the tree like tiny owls. The cones of other native conifers hang down or point this way and that. However, if you are standing in a forest of large trees, you probably can’t see the cones. This is where the other unique character of fir cones will help. Rather than drop old cones like most other conifers, fir cones disintegrate on the tree when they disperse their seeds, leaving a thin spike on the tree. So if you are standing in a forest of conifers and there are no cones on the ground, they are probably all fir trees.

Grand Fir                    Noble Fir
Pacific Silver Fir         Subalpine Fir
A better way to identify a fir tree is to look at the needles. Unlike the short, unruly hemlock needles, fir needles are long and orderly like they had been combed. The needle tips of Northwest firs are soft, unlike the prickly spruces. The needles do not grow in bundles like those of pines and larches. As a final and definitive test for a fir, look at a twig that has lost its needles.  The scars left on the twig will be smooth and round. They are rare, but you might come across a yew, which has similar needles. You can tell the difference by looking at the lower surface of the needles. Each fir needle has two bands of white bloom on its lower surface. On the other hand, yew needles are a lighter shade of green underneath.

The firs are closely related and often look similar, which can make it difficult to tell one species from another. To make matters worse, when two species grow in the same locale, they often interbreed. For example noble fir (Abies procera) interbreeds with red fir (Abies magnifica). As you travel south in the Cascade Mountains of southern Oregon, noble fir begin to look more and more like red fir. You can see this change by observing the bracts that protrude from the cones of noble fir. As you go south, they become shorter and finally disappear from the cones of red fir. The hybrids are called Shasta Red Fir, (Abies magnifica x procera.)*

Considering the similarities and cross-breeding, it’s no surprise that there is so much disagreement about the number of fir species. The number in recent classifications ranges from 39 to 55. A Handbook of the World's Conifers by Aljos Farjon (2010) lists 47. Conifers of the World by James Eckenwalder (2009) lists 40.

Noble Fir
Everyone loves firs for their beauty. The varied hues, from the dark green Pacific silver fir to the bluish noble fir, and their iconic conic shape make them a favorite for landscaping and Christmas trees. Although fir lumber is not as strong as other conifers, it is widely used for plywood and framing lumber. You can find it in the lumber yard sold as “Hem-Fir.” This wood is one of the fir species or western hemlock (Tsuga heterophylla). The wood is soft with a light color that easily takes a stain, which makes it ideal for moldings used trim doors and windows. The light-colored wooden moldings you see at any lumber yard is likely Hem-Fir. The wood is not fragrant like cedar, but many products sold as “pine scented” get their fragrance from fir bark and foliage.

Northwest Fir Species
The following firs are native to the Pacific Northwest:
Grand fir (Abies grandis) – Needles flattened on twig. Grows below 5000 ft.
Noble fir (A. procera) – Needles bent like hockey sticks. Grows above 2000 ft.
Pacific silver fir (A. amabilis) – Needles dark green on top, pointing up & forward. Grows above 2000 ft.
Subalpine fir (A. lasiocarpa) – Needles curve upward with white lines on both sides. Grows above 4000 ft.

The following, which grow in the mountains of southwest Oregon, are considered to be hybrids* with white fir and red fir, which are native to California:
Shasta red fir (A.magnifica x procera) – Needles like noble fir.
White fir (A. Abies concolor x grandis) – Needles 2” long with white lines on both sides.

See also

*The Gymnosperm Database and Oregon Flora Project list these as Abies magnifica x procera..

Wednesday, January 13, 2016

Climate and Forest Offsets

The recent climate agreement in Paris reminds us that we need to drastically reduce our use of fossil fuels to prevent the rise of emissions of carbon dioxide (CO2), a greenhouse gas that causes climate warming. However, reducing our dependence on fossil fuels is hard. We love the convenience of getting in our cars and driving where we want to go. Our lifestyle and our economy depend on energy driven in large part by burning fossil fuels. Yet there is an alternative to reducing fossil fuel usage. Instead of reducing the amount of CO2 we add to the atmosphere, we can pay to have someone else to remove CO2 from the atmosphere somewhere else. This kind of trading is called a carbon offset. For example, you can offset a flight across the US by buying an offset created by planting trees in the UK. The amount of CO2 you release into the atmosphere is offset by the CO2 absorbed by the trees you paid for. You can fly or drive wherever you want with a clear conscience because your carbon emissions are compensated by the offsets that you buy.

Plantings of Douglas fir
Planting trees is certainly an attractive option. Besides reducing atmospheric CO2, there are other benefits to the environment from planting trees and restoring forests. However, the practice of buying carbon offsets recently has come under increasing criticism. Some have compared it to indulgences sold by the Catholic Church in the Middle Ages. Similarly, now you can buy indulgences to offset your environmental sins.

Does this strategy of planting trees to offset our burning of fossil fuels actually reduce atmospheric CO2? Critics have documented serious problems with this approach. Vendors selling these offsets are notoriously untrustworthy. Often very little money from the offsets actually goes toward planting trees. The large projects promised by offset vendors often turn out to be a small fraction of what was promised. There is little oversight of these vendors to ensure that they are doing what they say they will do.

If we were to weed out the bad players in the carbon offset market, would it be possible to make a significant reduction in the emissions of CO2 by offsetting emissions with reforestation? There are several problems with offset schemes that undermine their effectiveness in reducing CO2 emissions.

The problem of additionality
If an offset is going to be genuine, it must pay for additional reductions in greenhouse gasses that would not have happened without the offset. If the project was going to happen anyway without the money from the offset, then buying the offset did nothing to reduce the greenhouse gasses. In many cases, offsets do not buy additional reductions. The offsets are sold for projects that had already been funded for other purposes. In some cases of tree plantings, offsets are sold for plantings that took place long before offsetting entered the picture.

Burned forest on Mt. Hood
The problem of permanence
The carbon stored in the trees in a forest does not stay there forever. Eventually the trees die. When they are destroyed by fire, insects, or disease, they release their carbon back into the atmosphere. Offset projects that finance tree plantations are particularly vulnerable to disease and insect infestations. Ironically, continued climate change can increase the threat of disease and fire. Natural forests can sequester large amounts of carbon, but it is important to maintain them in a healthy state to keep the carbon from returning to the atmosphere.

The problem of bad side effects
Most offset plantation projects are done in poor countries. These projects often displace local farmers and deprive local people of needed resources, particularly water. Critics view this practice of planting in poor countries to pacify emissions in the rich industrial countries as exploitation, calling it “carbon colonialism.”

The problem of future-based offsets
Offsets based on tree plantations do not reduce CO2 at the time of purchase. It takes many years to remove the CO2 already released into the atmosphere. For example, suppose I like to vacation in Hawaii every year. Each year I purchase an offset from a seller that plants trees. The offset pays to plant a tree that over the next 90 years will absorb the CO2 released by my flight. The problem is that the CO2 was released all in one day during the flight. As long as I continue flying and buying offsets, the CO2 released will increase faster than the CO2 captured by the trees. Offsets based on future CO2 reductions are fundamentally flawed. We may think that we are doing the right thing, but the results are continued climate warming from increases in atmospheric CO2.

Healthy natural forest
Tree planting offset schemes fail to deal with rising CO2 levels. Focusing on these flawed schemes is a dangerous distraction from dealing with the root cause of climate change. We must make serious reductions to our burning of fossil fuels if we have any hope of avoiding climate changes that will have dire consequences for the natural ecosystems of the earth and the people that live on the planet.

The bottom line is that it’s important that we focus on real reductions in fossil fuel use if we want to prevent climate changes that threaten the health of our forests and our planet. Preservation and restoration of forests is an important part of this effort. But we should not fool ourselves by thinking that we can continue to accommodate current levels of carbon emissions by offsetting them with tree planting.

Old person and older Douglas fir
See also

Carbon offsetting - Explain that Stuff

The Carbon Neutral Myth (PDF)– Offset Indulgencies for your Climate Sins

Designed to fail? (PDF) – The concepts, practices and controversies behind carbon trading


Monday, January 4, 2016

Forests and Climate

How do forests affect the climate?

Douglas fir forest
We all experience how a forest can affect the local climate, moderating both hot and cold temperatures. On a larger scale, can forests affect the global climate?

The climate of our planet is warming. It is common knowledge that climate scientists have attributed this warming to increasing amounts of greenhouse gasses in the atmosphere, mainly carbon dioxide (CO2), and that the primary source of the increase in CO2 is the burning of fossil fuels. It’s also well-known that plants, and especially trees, remove CO2 from the atmosphere, storing the carbon and releasing the oxygen back into the air. It stands to reason that preserving existing forests and planting new forests would tend to reverse the increasing levels of CO2.

However, the relationship between forests and climate warming is a complex one, and the effect that forests have on climate is a mixed one. Some forest types are more effective at storing carbon than others. Tropical forests generally store the most carbon per acre, but old-growth temperate forests can actually store more carbon than a tropical rain forest. Preserving and restoring forests in these areas can help mitigate the effects of rising CO2 levels.

Fragmented forest near Mt. Hood
On the other hand, the northern arboreal forests do not store great amounts of carbon. Furthermore, they can contribute to global warming, because they absorb more heat from the sun than unforested land in the polar regions. More sunlight is reflected from areas covered by grasses or snow. So restoring or planting new forests in the northern regions is not an effective way to reduce global warming.

Unfortunately, continued deforestation is adding significant amounts of CO2 to the atmosphere. In the last 40 years almost 20% of the rainforest in the Amazon has been lost. Almost 20% of global greenhouse gas emissions are from deforestation, more than the total emissions from cars, busses, and airplanes.*

Deforestation in the Amazon
Recent efforts to mitigate rising CO2 in the atmosphere have focused on planting new forests. However, efforts to plant new forests often prove to be ineffective, and the result can be more detrimental than the benefit of storing the CO2. Instead of restoring natural forests, many of these efforts are plantings of monoculture supported by the use of herbicides and commercial fertilizers. Also, these plantings often replace natural forests, displace local people, and disrupt their livelihood.

To make matters worse, these plantings, rather then decreasing the rise of greenhouse gasses, often are done as trades that allow big industry to release those very gasses that contribute to global warming. The net benefit of these efforts is zero.

In spite of these problems, preserving natural forests is necessary to prevent the release of their stored carbon. If done correctly, restoring forests can remove significant amounts of CO2 from the atmosphere. However, we should not fool ourselves into thinking that these efforts can solve the problem of rising CO2. To solve that problem, we must stop burning fossil fuels and move to renewable sources of energy.

How does climate change affect forests?

First we must realize that natural forests have adapted to the climate that exists where they grow. In the Pacific Northwest, it has taken thousands of years for our forests to adapt to the current climate. If the climate changes suddenly, trees cannot just fly to a more suitable location like migrating birds. Trees can migrate over long distances, but it may take thousands or millions of years. They can adapt to a changing climate in place, but this would also take thousands or millions of years. They cannot readily adapt to rapid climate change.

As the climate warms and rain patterns change, our forests may be more likely to suffer damage, leaving them more vulnerable to disease, insect infestation, and catastrophic fire. Thus, our efforts to preserve forests to prevent climate change can be undermined by the climate change we have already caused. If we want to protect our forests, we must significantly reduce the use of fossil fuels and move to renewable sources of energy.

Subalpine trees on Mt. Hood - Will they move higher as the climate warms?

See also