Scarification plays a key role in improving the chances of survival and the conditions for growth of a seed or plant. The problems encountered when establishing a new forest are the same no matter where in the world it is planted. Just as in agriculture, the greatest risk of harm comes from vermin and competing vegetation in fertile soil. This is the main advantage of scarification: protecting the seed or plant during its start in life, when it is most exposed to attack by vermin and competing vegetation. In the northern regions of the globe, however, improved growth is the more important aspect as attacks by vermin are not as severe. Naturally, the positive effects of scarification are complex, and it is difficult to rank and compare them. The cumulative advantages of increased survival rates and improved growth are, however, unequivocal. As such, scarification gives the seed or plant a helping hand.
At northern latitudes, the growing season is short, with trees generally growing from May to September. The temperature is seldom high. Proper scarification provides higher air and ground temperatures, lets in more sunlight, provides more nutrients, and improves the water balance of the soil. All these advantages provide increased growth during the plant’s first year, corresponding to that of plants several degrees further south. Due to the temperature difference, the growth aspect increases in importance as one moves north.