Wind

• Sitka spruce (Picea sitchensis) is the largest species of spruce and the the fourth largest conifer in the world. Sitka spruce is the third tallest conifer species, surpassed only by the costal redwood and the coastal Douglas fir. Native to the west coast of North America, the tree derives it name from the community of Sitka, Alaska. In their native habitat, Sikta spruce are constantly battered by strong, cold winds. Many trees have adapted by bending and growing in a form and direction determined by the prevailing winds. Because the winds are coming in off the ocean, the trees have developed a high tolerance to saline ocean air.
  
  

Soil Content

• The majority of evergreen trees require nutrient-rich, well-drained soil. Different species have different methods of adapting to less than ideal conditions. Trees attempting to grow in rocky, shallow soil cannot develop deep and strong roots. The tree may develop aggressive, above the soil surface roots as an anchor. Trees with insufficient moisture may develop wandering, spreading roots that branch out in search of water. Most trees growing in a soil with a pH level of 8.0 or higher will be stunted and deformed, never reaching their true potential.
  
  

Insect Infestation

• All across the United States, stately evergreen forests are experiencing devastating insect infestations. Several different species of beetles, wasps and borer are attacking the trees, contributing to their decline or death. Evergreens may produce an excessive amount of pitch to try to ward off the attack. Trees that survive the many different species of insects common to evergreen forests, may exhibit stunted or unusual growth patterns. Burls or "conks" may develop at the site of the insect attack.
  
  

Snow and Ice

• Heavy winter snow and ice accumulations exerts tremendous weight and pressure on evergreen trees. The tree will twist and bend under the weight of the snow and remain that way until the snow and ice melts in spring. When the tree is free of the snow, it will naturally lean towards the sunlight. If staked and supported, the evergreen will grow straight and tall. In nature, young seedling will continue to grow but may retain their shape as distorted by winter weight. Mature trees may suffer broken branches or severed trunks, dependent on the weight of the frozen water build-up. Evergreens growing in rocky, shallow soil may be up-rooted by the weight of heavy snow and ice.