Shade tolerance is the relative capacity of tree species to compete for survival under shaded (which is to say, less-than-optimal) conditions. It is a tree trait, a functional adaptation that varies among species. Because of its outsized influence on tree survival and stand growth, shade tolerance is a pillar of silviculture. Foresters everywhere commonly rank tree species on a continuum… (more)
Once upon a time, forest stand structure meant age structure. Areas of forests containing similar-aged trees were called even-aged stands, and areas with trees of multiple ages were considered uneven-aged stands. It was all quite straightforward. Stand structure was defined by how many trees were present in each age class within a given stand. It was beautiful. This view of… (more)
Trees are about half water, maybe a little less in winter. And if the temperature drops low enough, the water in even the most cold-hardy tree will freeze. Since ice crystals can shred cell membranes, a hard freeze can be devastating to living tree cells, leading to dead leaves, branches, and even whole trees. But most trees actually live through… (more)
Indicator plants are peculiar to a certain place. Though they aren’t necessarily rare, they don’t grow just anywhere. They tolerate only a narrow range of growing conditions, so their presence in a forest signals some distinctive aspect of that place. Not all plants are so uniquely characteristic of specific conditions. Really, most aren’t. In the dizzying complexity and variation that… (more)
“I want to cut some firewood but don’t want to jeopardize my valuable timber trees. How do I choose which trees to cut?” You can make firewood from most any hardwood, but you can only make sawtimber from those with the best form. Even in a down market and with expanded options for selling fuelwood, it still pays to know… (more)
Pollen is to trees what sperm is to animals. It carries the tree’s male genes; it is the male fertilizing unit of woody plant reproduction. Typically, pollen appears in spring as a powdery cloud of fine, yellowish grains. Each tiny grain is a single cell, encased in a tough, ridged, or spiked coating. When inhaled by susceptible people, these grains… (more)
Those white paint-like bands across the bark are lichens, and they are as normal and natural a part of healthy forests as are warblers. There are several others present on this tree and throughout the woods. Lichens exist in beautiful diversity, and the vast majority of them do absolutely no harm to trees. Better still, lichens play several vital roles… (more)
Trees grow where they can. And they are surpassingly capable, making do in an impressive array of conditions around the globe, including many harsh places. But there are limits to their versatility. There are some natural environments where trees simply do not grow, thrive, or even survive, such as near the tops of the bigger mountains. As you hike up… (more)
Every acre contains the same measure of land regardless of whether it is steep, bowl-shaped, or the Great Plains. This is due to long-standing conventions of land surveying and accepted procedures for determining ownership boundaries. There is definitely a catch, however, in that not every measured acre contains the same amount of ground surface. In other words, you’d need a… (more)
Knots in trees occur where a branch has been surrounded by continued growth of the bole. When the bole is sawn into lumber, or peeled to make veneer, the branch sections included in the lumber or veneer show up as knots. Whether a knot is red or black was determined back when the tree was growing. If a branch and… (more)