2.1 Study area description
The study was conducted in Luoxi Town, Taihe County, Jiangxi Province,
China (114.47′41.55″E, 26°51′14.73″N). This site has a subtropical
monsoon humid climate with mean annual precipitation of 1438 mm, mean
annual temperature of 18.9 ℃ and mean annual relative humid of 79 %
(http://data.envbox.net/). The soil is red soil developed from a
quaternary red clay, characterized with almost no humid layer and full
of gravel on the surface due to water erosion.
Masson
pine, an evergreen coniferous tree, is an important species for timber
production in southern China and its rosin is also one of the most
important chemical raw
materials.
In addition, this species
has
become an excellent pioneer tree species for afforestation of barren
hills in China, due to its resistance to drought and barrenness and
strong adaptability. Consequently, aerial seeding of Masson pine has
been widely established in southern China to limit the intensive soil
erosion and accelerate the restoration of forest vegetation (Xiaoet al. 2015).