Comparative analysis of the competition of stands of different species composition in relation to the Siberian stone pine undergrowth

Under the canopy of the parent native berry-green-moss Siberian stone pine forest and derivatives berry-green-moss pine and birch forests on the Urals, using the previously proposed complex of light, root, and integral competition indices of the stand, a comparative analysis of the parameters of the Siberian stone pine undergrowth is carried out. Under the canopy of Siberian stone pine forest two main determining factors have a negative complex effect on the growth of the Siberian stone pine undergrowth: the light competition of the stand (the level of photosynthetically active radiation interception by its canopy) and, almost equal to it, the root competition for soil nutrition. Under the pine forest canopy with the combined negative effect of factors of light and root competition of the stand on the development of Siberian stone pine undergrowth, light competition is decisive. The effect of the root competition is less than almost two times. Under the birch forest canopy the main factor determining the development of Siberian stone pine undergrowth is the light competition of the stand. The connection with the root competition of stand is not expressed.