Composition and structure of regrowth forests on abandoned agricultural land

Overgrowing of agricultural land by forest in Russia is a large-scale process. This study aims to examine the composition and structure of forests that took over abandoned agricultural lands in Belorechensky district, Krasnodar Krai (Russia). The research on 4 farmland plots was carried out in 2018. At the time of observation agricultural land has been abandoned for 7 to 8 years. Research methodology was developed to determine parameters such as tree and shrub density per ha, height and age at 50 m and up to 100 m from the forest. Two study sites were dominated by mesophytes, whilst the other two sites were invaded by xerophytes. Xerophytic landscapes were co-dominated by downy oaks and dog roses. The stand density of examined plants was 1.7 times lower at 51 to 100 m than near the forest (P ≤ 0.05). There were 3.3 times as many dog roses as downy oaks. The stand density of common ash stand at 51 to 100 m from the forest edge was 10 times lower than that of dog rose (P ≤ 0.01). Mesophytic landscapes were co-dominated by black poplars and crack willows. Black poplar was 4.3 times more frequent than dog rose (P ≤ 0.002) and 130 times more common than elm (P ≤ 0.0001). Natural overgrowth or succession can affect vast areas of land. It was established that dog roses and downy oaks regenerate xerophytic fields within 6 to 7 years, whereas mesophytic fields become dominated by black poplars and crack willows within 5 to 7 years.