|
Evergreen or Conifer?
By Susan Butterfass
They're so much more noticeable now - those lovely, dark-green, often triangular trees that smell so nice. What do we call them? Evergreens? Conifers?
Evergreen means that they don't lose their leaves all at once, remain leafless during the coldest part of the year and then grow new leaves in the Spring. This is a defining characteristic in the Northeast, as so many of our trees are deciduous (leafdropping). In the South and the tropics, however, many tree species similar to the ones we call deciduous retain their leaves all year long, and are therefore technically evergreen. We also have some broad-leaf evergreens, such as rhododendrons and mountain laurel, which have very little in common with what we usually think of as evergreens, as well as trees with needles that turn yellow and fall off every year (larches). This muddies the waters further.
How about conifer? The word is from Latin and means "conebearing". Certainly the familiar pines, spruces, hemlocks, and firs all have cones, but birch trees have seed-holders that look like cones, too. If you want to get scientific, what we usually think of as conifers are gymnosperms - naked seeds, which germinate quickly - as opposed to the deciduous angiosperms - seeds in a container (like apples, peaches, or walnuts), which are slower to sprout. The scientific community usually calls the trees in question conifers.
What would be the advantages these naked-seed trees have for survival? Well, where do they usually grow? Many are found in Northern areas, such as the boreal forest, where living conditions can be harsh. Soil is thinner, land is rockier, water is scarcer, and winter is longer, colder, drier, and windier. What adaptations do these trees have to help them survive?
First, their leaves are needleshaped, which reduces surface area and thus lessens water loss. Each needle has a tough waxy cuticle, which also cuts evaporation. The needles are slippery, so although snow can build up on them, it often slides off before branches break, and wind is therefore less of a damaging factor, too. Roots are shallow, an important consideration in rocky, thin soil, and there is no long tap root. In addition, because the cells are protected by a form of antifreeze, the tree is much less subject to damage by freezing. Because these trees can make food for themselves by photosynthesis throughout even the shortest days of winter, they are capable of growing rapidly from a tender seedling to a sturdy adult much less likely to die from environmental stresses. Conifers also tend to grow in areas where nutrient levels are relatively low, or the ground is so cold that organic matter decays slowly, limiting available nutrients; when a deciduous tree sheds its leaves, it loses nutrients, and coniferous plants living in cold or poorsoil regions cannot afford this loss.
Because they can survive under such adverse conditions, and because they appear green and alive in winter when other trees look dead, conifers have been used as symbols in folklore, culture, politics, and religion wherever people live for thousands of years. Aside from their symbolism of eternal life, survival, and renewal, they are also attractive and available in winter, when traditionally little else was around with which to decorate our homes.
As we approach the solstice, the time of least daylight when our ancestors were most fearful that the sun would not return, think of the conifers and all of their miraculous adaptations, and think about planting a conifer when the soil warms up!
| Click ads below
for larger version
System and Method for Display
Ads have a Patent Pending.
Click Here for More Information
|
