Introduction
Alaska remains as one of the most ecologically diverse regions in the globe with key ecosystems that are highly sensitive to both natural and human interference.
A closer look at Alaskan forests further reveals a region that holds diverse vegetation with highly varied geologic history and evolutionary progression. The main habitats in Alaska that harbor trees include the Boreal forest which sustains trees that can survive in temperatures that are as low as negative 30 degrees Celsius.
Trees in this habitat are largely coniferous and evergreen during both winter and summer. Temperate conifers are further characterized by tall trees that grow to over 60 meters in height and last for over 500 years. This paper explores the key characteristics of different trees found in Alaska.
White Spruce
White Spruce which is botanically known as Picea glauca is an evergreen tree that belongs in the coniferous group. According to Tarpening and Tarpening (2010), this tree is generally medium-sized and reaches about 55 meters in height and generally asymmetrical with a conical crown.
This shape has been cited as a critical survival strategy that reduces snow sticking tendencies on its leaves during winter. The plant further branches in a pattern that extends to the ground held by a bark that is smooth dark and scary.
Legasy, Labelle-beadman and Chambers (1995) indicate that this tree is shallow-rooted with the tap root which only reaches a maximum of 300 meters depending on the type of soil.
It is important to mention that the roots are associated with Mycorrhizae which are mainly used in fixation of nitrogen.
Birch
Birch’s botanical name is Betula pendula and grows in the Northern temperate zones at latitudes of between 50 and 70 degrees. This tree is medium-sized and adapted to most cold regions.
Leaves are simple in shape, petiolated and alternate in arrangement (Tarpening & Tarpening, 2010). Branches and trunk are mainly gray and further split into several layers as the tree grows older.
An important point to note is the direct visibility of lenticels that enable effective gaseous exchange even during winter. The tree produces differentiated male and female flowers.
The male flower appears grouped into trios with two to four filaments while the female one holds 2-3 similar filaments (Legasy, Labelle-beadman & Chambers, 1995).
Aspen
The botanical name for Aspen is Populus tremula. It has become to be widely known for its different uses. The tree is characteristically thin in its trunk and has white bark that is smooth and creamy.
The leaves are round and measure about 3 to 6 centimeters with blunt margins (Legasy, Labelle-beadman & Chambers, 1995). The petioles are flat and generally remain flexible at the base.
Notably, the tree is generally thin and therefore less effective for heavy duty woody activities such as those exhibited by others like Birch and Cotton wood.
Balsam
Balsam’s botanical name is Abies balsamea. It remains as one of the key dominant species in Alaska. As a conifer, the tree is evergreen and typically grows to about 15 to 20 meters in height.
The bark is largely grey with major resin blisters. Leaves are needle- like and flat to reduce snow accumulation. It grows to about 30 millimeters.
Its leaves are arranged spirally but the leaves’ base are twisted to give the branches a flat shape (Tarpening &Tarpening, 2010).
From the above discussion, it is evident that trees in Alaska are specially adapted to the extreme cold climate with their leaves, bark and even reproductive cycle functioning in harmony during the various seasons.
However, continued invasion by man of different species remains an important factor that makes further studies of Alaskan trees to be of great importance.
References
Legasy, K., Labelle-beadman, S. & Chambers, B. (1995). Forest Plants of Northeastern Ontario. Ontario, Canada: Lone Pine Publishing.
Tarpening, T. & Tarpening, T. (2010). Alaska. Washington: Sage.