Secure change of stand structure and plant diversity of urban forests under conservation management activities by citizens

Abstract

In order to verify the appropriate conservation of urban forests, we used continuous survey data to analyze the secular change of stand structure and plant diversity of urban forests that are being conserved and managed by citizens. The survey was conducted every year for about 10 years by setting up three quadrats in different parts with different origins and management conditions. In the minimal management stand of middle-aged secondary forest, the number of evergreen trees in the lower layers gradually increased. There were few non-forest type species in this stand, and there were many evergreen trees originating from garden trees. In the brightly maintained stand of middle-aged secondary forest, many summer green trees invaded the lower layer, and the current stand structure was maintained in a dynamic equilibrium state by continuous management. Many non-forest type species were also found here. In the young artificial forests, the canopy height was low and not closed in the fourth-grade stands, but in the final year of the survey, a closed tall tree layer was formed. Initially, there were few forest type species and many alien species, but the species composition of the young artificial forests approached the species composition of middle-aged secondary forest year by year. Young plantations have the same diversity as conserved forests due to natural invasion from adjacent sources of forest-type species. In this forests, stands with high diversity and which have many non-forest type species, and stands which are dark but require minimal management, are maintained according to the needs of each location.