Project info
Project start date: 1 January 2022
Planting trees in South-east Europe, Bulgaria.
Location of project's activity
Five of the six afforestation sites fall into an area that is relatively homogeneous in its characteristics, with humus-rich soil (3.27 ± 0.23%), with a neutral to slightly alkaline reaction (pH = 7.36 ± 0.12) and with significant variations in terms of macronutrients N, P, and K, probably due to agricultural heterogeneous use in the past. All three elements are mobile enough so that the established variation does not have a significant impact in the medium and long term in a forest culture.
The sixth site (43846.29.46) differs as its soil has lower humus content, which suggests a tree species that is less demanding to soil fertility. The availability of nitrogen (mainly inorganic) is high, and soil is not inferior to the other five sites in terms of other elements.
The humidity index (NDMI = (B8A-B11) / (B8A + B11)) in the area determined by satellite photos taken by Sentinel-2 satellites shows that over the last 5 years the humidity conditions have become favourable for active growth processes in this area a little after the beginning of April and the permanent drying of soil occurs between the middle and the end of August (Fig. 1).
Fig. 1. Afforestation site humidity index in the Lisivrah area. Data refer to the last 5 years (2017-2021). The index has been determined via satellite photos taken by the Sentinel-2 satellites.
The index becomes positive after 23 April (± 5.3 days) and remains so until 13 August (± 7.6 days). This fact demonstrates that in order for afforestation to be successful, it is necessary to select a sufficiently drought-resistant species, such as Cerris oak and Hungarian oak.
Cerris oak is recommended, given the flatter nature of the terrain, but the Hungarian oak would also be successful and they may be combined in a mixed culture. Other tree species from the main list are also suitable.
The afforestation scheme should be in accordance with the peculiarities of the indicated tree species, but also with the purpose of afforestation - 1.5 - 2.0 m between rows, but at a higher density of 0.75 - 1.0 m in them.