26 January/February 2016 Landscape and Irrigation www.landscapeirrigation.com
BY BRANDON M. GALLAGHER WATSON
In the upper regions of Siberia, nearly 450 miles above the Artic
Circle, resides one of the world's toughest tree species. Larix
gmelinii, known as the Dahurian larch, holds the distinct title
of "World's Northernmost Tree Species." Living in this area,
just above the permafrost layer, is not for the faint of sap. Air
temperatures have been recorded at an astonishing negative
94 degrees Fahrenheit (-70°C) during the winter, and summer
temps climb above the freezing point for just a few short
weeks. The growing season is
less than 100 days long each
year with polar night lasting
from September to February.
This species has adapted to
low seed germination rates
with the ability to sprout
new trees off its root system,
forming forest colonies of "creeping larch." This growth habit
is common among hardwoods, such as aspen, but uncommon
amongst temperate conifers. Their tough wood and extreme
cold keep insect and fungal pests to a minimum and, of the
268 other organisms that live on this tundra, there are no
other tree species competing for sunlight. They can survive
here for a long time. One individual was found to be 919 years
old, while the root system may be as old as several millennia.
Despite these inhospitable conditions, the Dahurian larch
thrives here.
The Dahurian larch endures
the local climate with great
success thanks to a fairly
complex series of adaptations
we generally refer to "cold
hardiness." Hardiness is a
measure of how well a plant can
withstand adverse conditions,
"Hardiness is a measure of how well a
plant can withstand adverse conditions,
and can include cold, heat, elevation,
drought, flooding and even wind."
ALL
PHOTOS
PROVIDED
BY
RAINBOW
TREECARE
SCIENTIFIC
ADVANCEMENTS
Just Chill:
How Cold Hardiness Works
TREE CARE