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.

Sunday, March 12, 2017

On Conifer Names

Botanical names seem to have a special status in our language. When we know the name of a tree, we often feel like we have gained a special knowledge of that tree. Many names describe the tree or tell you where it grows. Some tell who discovered it. So learning the name of a conifer often does tell you something about that species. More importantly, learning the names forces you to look more closely at the different characteristics of each tree so you can distinguish it from other similar ones. Learning the names of the conifers is not the be all and end all of knowledge, but it marks the beginning of a relationship. It allows you to become acquainted. Deeper knowledge comes later when you can take the time to observe more carefully and completely.

Most conifers have two types of names: A common name and the scientific name. A good place to start is with the common names.

Common names
Douglas fir - Pseudotsuga menziesii 

Like many other plants, conifers have names that are determined by common usage. Sometimes a conifer will have several common names used in different regions. Learning the common name is an easy way to identify a tree. The names are familiar and easy to remember. However, common names can be misleading. For example, none of the native Oregon cedars are true cedars. Cedars are native to the Middle East and the Himalayas. They are in the pine family and appear to be cousins of the firs. When Europeans came to North America, they encountered trees in the cypress family that had wood like the wood of the Old World cedars. So they naturally called them cedars. Many conifers get their common name because of the nature of their wood. It's not so surprising that people would name things based on the use they make of them.

Many trees called pines are not really pines at all. In the nineteenth century, English botanists circled the globe looking for new conifer species. They often called anything with needles on it a pine. Even Douglas fir was called a pine at one time. The Norfolk Island pine you find in stores each December is not even in the pine family. And the rare Japanese umbrella pine isn't in the pine family either. The Norfolk Island pine is in the Araucaria family in the same genus as the monkey puzzle tree. The Japanese umbrella pine is the only species in a family of its own.

Western hemlock - Tsuga heterophylla
Some writers have attempted to mitigate the misleading nature of common names by writing them differently, for example, "western redcedar," "Douglas-fir," and "Port-Orford-cedar."  But these strained artifacts don't really mitigate the confusion. The spoken name sounds the same. Even the written names don't convey the intended information. Any normal person seeing "redcedar" in print would still think that it's a cedar. And the names still don't tell you what genus or family the trees belong to. We should just realize that common names are not scientific names. In fact, one reason we have scientific names is to clear up this kind of confusion. If we want to use a name that correctly identifies the scientific classification of a tree, we will have to learn the scientific name.

Scientific names

Each conifer species also has a scientific name. Why learn the scientific name? These names give you an unambiguous way to identify a species. These names are assigned and agreed to by botanists based on rigorous classification of each plant. Each species is assigned to a general grouping or genus and given a unique species name. The names are Latin or at least given a Latin ending. The name for a species written as Genus species, written in italics with the genus name capitalized. For example, the scientific name of grand fir is Abies grandis. This name is universal throughout the world, no matter what language is spoken.

Grand fir - Abies grandis
As a practical matter, knowing the scientific name usually tells you something about the tree. For example, the name of western hemlock is Tsuga heterophylla. Tsuga is Japanese for hemlock. And heterophylla means variable leaves, which aptly describes western hemlock needles. Also, if you want to learn more about a tree, it helps to know the scientific name. Much of the scientific literature references species by the scientific name. Familiarity with these names will help when you see them in scientific writings.

Western red cedar - Thuja plicata
Even though scientific names give us a more precise way to identify each species, that's not to say that there's no confusion with these names. They may change. Science is not static. As botanists learn more about a tree, they may change its classification to a different genus. These changes generally generate a lot of discussion among the experts and confusion for the rest of us. Such a discussion has been raging about the classification of Alaska cedar. It was in the genus Chamaecyparis, the same genus as Port Orford cedar. Recently someone proposed putting it in a new genus called Xanthocyparis. Others have countered, saying it should be classified as Callitropsis or Cupressus. And some are proposing that all the Cupressus that are native to the New World should be placed in a separate genus called Hesperocyparis. Many other names have changed over time. Botanists had a terrible time classifying Douglas fir. Its name changed 21 times before they finally settled on Pseudotsuga menziesii.

Note that scientific names can also be misleading. For example, the scientific name of incense cedar is Calocedrus decurrens. The genus name means "beautiful cedar." Even the scientific name suggests that the species is closely related to the genus Cedrus, which it is not.

Getting Started

The photos above show the common conifers found at low elevations (below 2000 feet) in northwest Oregon. Look for these when hiking in Portland's Forest Park and other nature parks nearby.

Take some time to learn the names of our native conifers. It will help you become acquainted with them. Given some time and attention, you may even become friends with some of them.

For more help identifying our native conifers, go to Northwest Conifers.

Tuesday, March 7, 2017

Will Conifers Weather Global Warming?

Recent posts on this blog looked at how conifers survive the snow and cold. As increasing carbon dioxide in the atmosphere causes climate warming, cold may become the least concern for our forests. But how will conifers deal with the fact that the climate is getting warmer? As with everything related to the life of living things, it's complicated. But we can see some of the effects of climate change because they are happening now. And we can see some future potential outcomes just by understanding something about the lives of trees and how they react to their environment.

At the outset, it is important to remember that, like all living things, conifers growing in the natural environment are adapted to the climate conditions where they are. Each species is adapted to survive where it grows. In the Pacific Northwest, it has taken thousands of years for our forests to adapt to the current climate.

Going up north. One response to warming climate is to move to where it is cooler. Birds can fly to cooler temperatures in the north. Even mammals can move up slope to cooler locations in the mountains. But these options can be a problem for trees. Roots do not make good legs. Even so, successive generations of trees can move as each generation distributes its seeds a few hundred feet. Yes, trees can migrate over long distances, but it may take thousands of generations and millions of years. When climate change is rapid, migrating trees cannot keep up.

Trees marching up Mt. Hood?
Migrating up slope also can present significant problems. The space gets smaller as you near the top of the mountain. And if it becomes too hot for you at the top, you just have nowhere to go. Migrating north can present barriers as well. Mountains can be a barrier, as can rivers, lakes, and even oceans.

Adapting. Natural selection enables trees to adapt. When conditions change, the genetic variability in a population will enable some trees to survive and pass their genes to the next generation. In this way, a species can adapt to a changing climate in place, but like migration, this process could also require thousands or millions of years. Trees cannot readily adapt to rapid climate change.

Are we then putting our forests in danger by causing global warming? Well, the answer to that is complicated, and varied. The temperate forests of the Pacific Northwest will likely be less affected by climate change than those in the southwest U.S. Also, the consequences of climate change for forests is not just about rising temperatures. There are related factors that may more seriously impact our forests.

Vista Ridge fire on Mt. Hood
Drought.  As the climate warms, weather patterns change. Most seriously, rainfall patterns change. Some areas will get more rainfall. Some will get less. Entire forests may be plagued by drought. In these forests, tree species that are drought intolerant will not survive. Mild winters also contribute to summer drought. Winter snowpack stores water that melts in the spring and provides water for growing trees. However, warmer temperatures bring rain in winter instead of snow. The runoff comes early, and trees are left high and dry in the summer.

Wild fires. Drought-stressed forests are subject to an ever increasing risk of wild fires. With increasing drought, fires burn hotter and are more destructive. We have already seen recent devastating wild fires all over the western U.S.

White pine blister rust is killing 
pines on Mt. Hood
Insect invasions and disease. Trees weakened by drought are also vulnerable to insect invasions and disease. Winter cold can help keep insect invasions in check. But with warmer temperatures, the insects can survive the winter and attack forest trees in force the following summer. Recent mild winters have enabled the mountain pine beetle to destroy millions of acres of lodgepole pine and ponderosa pine forests in western North America.

More carbon dioxide. One mitigating factor for forests and other plants would seem to be the increasing levels of carbon dioxide in the atmosphere. The very thing that is causing global warming could be a boon for our forests. They use carbon dioxide and store the carbon in root, limb, and their massive trunks. Perhaps we can look to forests to store carbon and help prevent more global warming. However, this scenario may not pan out as well as you might think. Just as trees are acclimated to their climate, they are also acclimated to the amount of carbon dioxide in the atmosphere. They won't necessarily grow faster if carbon dioxide concentrations are higher. Other factors often limit growth. Some experiments have shown that increasing carbon dioxide levels does increase production in some conifer species. Others, not so much. Furthermore, forests decimated by drought, wild fires, and disease won't benefit at all from increased carbon dioxide. Thus, our efforts to preserve forests to prevent climate change can be undermined by the climate change we have already caused.

Forest conservation. One thing is clear: Preserving our forests is important. They can be a significant repository of carbon. Forest destruction only adds to the rising carbon dioxide in the atmosphere. How we protect forests from the effects of climate change is not as clear, but much research has been done. Some work is being done to develop trees that are resistant to disease and can tolerate changes in climate. Foresters are planting trees in new locations where they can thrive. Yet, more research is needed to determine the effects of the changing climate on forests and develop ways to help forests adapt to change.

How can we help? We can support restoration and reforestation efforts. Planting trees is good exercise, too. We can also reduce our consumption of fossil fuels by avoiding travel in fuel-burning cars and airplanes, and instead opting to travel by electric cars, bicycles, and our feet. We can make other lifestyle choices that leave a smaller carbon footprint. We can live more simply and install solar panels on our houses. We will have a smaller impact on our planet, and the the trees in our forests will be happy.

See Also

Climate change’s effects on temperate rain forests surprisingly complex

CNN:Global warming threatens forests, study says