In the regioning of the seed transfer of pine species, two criteria are used. One of them is relative moisture of the growing season or vegetation period, and the other is the duration of the growing  as a day in the year. In addition, the features of orography, continenteality, expose and height were taken into consideration.

     For the determination of the vegetation periods or the duration of growing seasons, daily average temperatures of 8 C and more are accepted.

     In the growing season, relative moisture (humidity) ranges from 75 to 21 percent in Turkey. Especially, along the northern coast of the Black Sea Region, relative moisture varies between 70 and more than 70 percent, while in the Inner and South-east Anatolian , relative moisture is less than 40 percent.

     There is a wide range in the duration of the growing season in Turkey. In fact, the growing season ranges from 135 days in Kars (East Anatolian) to 353 days in Anamur (Mediterranean Region) . Generally, the seacoasts have about 230 and more growing days. The growing season in Inner and East Anatolian, is about 180 – 140 days.

     As a result, in the seed transfer, main regions are separated according to relative moisture and subregions are separated according to duration of the growing season.

     Pinus brutia forests are divided into 5 regions and 18 subregions; Pinus nigra forests are divided into 10 regions and 24 subregions; and Pinus sylvestris forests are divided into 5 regions and 11 subregions.