The role of canopy gaps in maintaining biodiversity of plants and soil macrofauna in the forests of the northwestern Caucasus

Nikolaj Shevchenko, Anna Geraskina, Alexander Kuprin, Evgeniy Grabenko



The research was carried out in the coniferous-deciduous forests of the northwestern Caucasus, growing in similar climatic and soil-orographic conditions. Three types of forests of different ages were studied: aspen-hornbeam (50-70 years), beech-fir-hornbeam (80-110 years) and fir-beech forests (over 450 years). The studies were performed on the territory Krasnodar Krai (upper reaches of the Pshekha river, State Nature Reserve Chernogor'e) and the Republic of Adygea (upper reaches of the Belaya river, the Caucasian State Biosphere Reserve) in the summer seasons 2016 and 2019. The research involves geobotanical, population-ontogenetic, and soil-zoological methods. It has been established that in the canopy gaps of all forest types species density of plants is almost twice as high as in under-crown areas or even higher due to good light factor and high soil moisture since the tree stand does not intercept precipitation. Regeneration of tree cenopopulations in all forest types is much more effective in canopy gaps compared to under-crown areas. The undergrowth density of different types of trees is 10 and more times higher in gaps than in the under-crown areas. The maximum number of ecological-coenotic groups of plants is observed in the canopy gaps in all types of forest. All major trophic groups of macrofauna inhabit canopy gaps and under-crown areas, but their biomass in gaps is significantly exceeds that in under-crown areas. Due to the fact that soil moisture supply is an essential factor for moisture-loving saprophages’ activity, biomass of saprophages is on average twice as high in gaps than under-crown areas of all forest types. Only canopy gaps have high biomass of anecic earthworms – there are important ecosystem engineers, which contribute a lot to plant litter processing and the formation of soil porosity.


earthworms; forest community; invertebrates; species richness; treefall gaps; trophic groups; saprophages; under-crown area; undergrowth

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