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.

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