Search results
Results From The WOW.Com Content Network
Trees can explode when struck by lightning. [3] [15] [16] [17] The strong electric current is carried mostly by the water-conducting sapwood below the bark, heating it up and boiling the water. The pressure of the steam can make the trunk burst. [3] [17] This happens especially with trees whose trunks are already dying or rotting.
The practice of girdling has been known in Europe for some time. [4] Another example is the girdling of selected Douglas-fir trees in some Northern California oak woodlands, such as Annadel State Park, in order to prevent that Douglas-fir from massive invasion of the mixed oak woodland. [5] Girdling can be used to create standing dead wood, or ...
Among the commercial products made from bark are cork, cinnamon, quinine [48] (from the bark of Cinchona) [49] and aspirin (from the bark of willow trees). The bark of some trees, notably oak (Quercus robur) is a source of tannic acid, which is used in tanning. Bark chips generated as a by-product of lumber production are often used in bark mulch.
Trees usually have a single main stem or trunk but many eucalypts are mallees that are multistemmed from ground level and rarely taller than 10 metres (33 feet). There is no clear distinction between a mallee and a shrub but in eucalypts, a shrub is a mature plant less than 1 m (3 ft 3 in) tall and growing in an extreme environment.
The trees have been pretty good stewards of the planet, providing free lodging to spotted owls, pacific fishers, flying squirrels and a host of other tenants while nurturing the ground beneath ...
The dark horizontal lines on silver birch bark are the lenticels. [1]A lenticel is a porous tissue consisting of cells with large intercellular spaces in the periderm of the secondarily thickened organs and the bark of woody stems and roots of gymnosperms and dicotyledonous flowering plants. [2]
Almost all burl wood is covered by bark, even if it is underground. In some tree species, burls can grow to great size. The largest, at 26 ft (8 m), occur in coast redwoods ( Sequoia sempervirens ) and can engirdle the entire trunk; when moisture is present, these burls can grow new redwood trees.
[5] [12] The dark color of these cones helps to absorb heat. After maturity, which takes about two years, the cones will become brown in color. [13] These ancient trees have a gnarled and stunted appearance, especially those found at high altitudes, [8] and have reddish-brown bark with deep fissures. [14]