Objective The comprehensive evaluation of healthcare benefits of different stands can not only provide the basis for the choice of forest therapy tourism, but also provide the scientific basis for the construction and management of healthcare forest in the future.
Method In the summer of 2020 (from June to August), five stands of Phyllostachys edulis forest, subtropical monsoon evergreen broadleaved forest, Liquidambar formosana forest, Cunninghamia lanceolata forest, coniferous and broadleaved mixed forest and a forestless control group in Shimen National Forest Park of southern China were selected. The variation characters of negative air ion concentration, air oxygen content, human comfort index and phytoncide relative content were analyzed. Principal component analysis and systematic clustering were used to construct forest comprehensive healthcare index and evaluation grade, in order to evaluate the healthcare benefits of different stands.
Result (1) In terms of negative air ion concentration, subtropical monsoon evergreen broadleaved forest ((8 377 ± 3 749) ions/cm3) and P. edulis forest ((4 257 ± 2 021) ions/cm3) were all at very comfortable level of gradeⅠ, meanwhile C. lanceolata forest ((2 930 ± 1 917) ions/cm3), coniferous and broadleaved mixed forest ((2 907 ± 2 012) ions/cm3), L. formosana forest ((2 529 ± 1 996) ions/cm3) were in comfortable level of grade Ⅱ , while forestless control group ((1 386 ± 556) ions/cm3) was at more comfortable level of grade Ⅲ. (2) The air oxygen content of five stands and forestless control group were all at higher level of grade Ⅱ, among them coniferous and broadleaved mixed forest was the highest (21.807%), forestless control group was the lowest (21.338%). (3) From the human comfort index, P. edulis forest (2.78) was the best, followed by subtropical monsoon evergreen broadleaved forest (2.81), forestless control group (4.85) was the worst. Five forest stands were at very comfortable level of gradeⅠ, forestless control group was in comfort level of grade Ⅱ. (4) In view of relative content of phytoncide, the subtropical monsoon evergreen broadleaved forest was the highest (21.11%), followed by the C. lanceolata forest (14.75%). From June to August, the number and relative content of phytoncide showed an increasing trend, and the phytoncide released by forest in different months showed a great difference. In June, the species were mainly terpenes (accounting for 50.7%) and alcohols. In July, alcohols (30.9%), esters and terpenes were mainly released. The relative content of phytoncide released in August was relatively balanced, mainly terpenes (23.1%). (5) Establishing forest comprehensive healthcare index (FCHI), according to the FCHI value, it was divided into 5 rating levels. The comprehensive healthcare function of subtropical monsoon evergreen broadleaved forest (0.904) and P. edulis forest (0.614) were in gradeⅠ, in which healthcare function was very obvious. C. lanceolata forest (0.455), coniferous and broadleaved mixed forest (0.407) and L. formosana (0.390) were in grade Ⅲ, in which healthcare function was strong. However, forestless control group in grade Ⅴwas not equipped with healthcare function.
Conclusion In summer, the healthcare effects of subtropical monsoon evergreen broadleaved forest are the best, followed by P. edulis forest. In the forest therapy tourism, it is recommended that tourists choose these two stands for recreation first. In addition, the landscape resources of subtropical monsoon evergreen broadleaved forest and P. edulis forest should be protectively developed in the planning and construction of forest therapy base, and the health care activity space should be rationally utilized. In the improvement of health care function in the stands transformation, the community structure of natural forest can be imitated and mixed forest of multiple tree species can be planted appropriately.