[Radial growth dynamics of Chinese fir and its response to seasonal drought].

We explored the seasonal dynamics and climate responses of radial variation of Chinese fir, we continuously monitored intra-annual stem radial size changes with the automated dendrometers in central Jiangxi Province in 2016 and 2017. We analyzed daily and seasonal dynamics of radial variations, and their Spearman correlations with climatic factors. We found that the diurnal radial variations had a pattern of contraction during the day and expansion at night.

[Response of radial growth of and to climate warming in the ecotone of Changbai Mountain, Northeast China].

Changbai Mountain is a typical distribution area of temperate coniferous and broad-leaved mixed forests, with significant influence of global climate change. In order to understand the responses of forest ecosystem to climate change, we examined the responses of dominant arbor species in the community ecotone of broad-leaved Korean pine forest and spruce-fir forest (also known as dark coniferous forest), and . The standard chronologies were established by obtaining tree ring width data in order to identity the key climatic factors that confine the radial growth of both species.

[Soil enzyme activities and their stoichiometry of typical plantations in mid-subtropical China].

We measured the activities of six kinds of enzyme, including β-glucosidase (BG), β-N-acetyl-glucosaminidase (NAG), leucine aminopeptidase (LAP), acid phosphatase (AP), polyphenol oxidase (POX), peroxidase (POD), as well as enzyme stoichiometric ratios and soil physical and chemical properties at 0-10 and 10-20 cm layers across typical Pinus massoniana plantation, Pinus elliottii plantation and mixed plantation of P. massoniana and Schima superba (broadleaved-conifer mixed plantation) in mid-subtropical China. Key factors driving the variation in soil enzyme activity and stoichiometry among different stand types were investigated.

Long-term monitoring of tree population dynamics of broad-leaved Korean pine forest in Changbai Mountains, China.

Based on four investigations of a one-hectare permanent plot in Changbai Mountains from 1981 to 2016, the changes of tree species composition and structure of broad-leaved Korean pine forest were examined, and diameter distribution, spatial pattern distribution, and quantitative changes of each tree species were analyzed. The results showed that there were little changes in tree species composition and an overall decreasing trend in total density in 35 years. Both basal area and stand volume were 43-45 m·hm and 474-496 m·hm, respectively.

[Response of radial growth of Pinus koraiensis and Picea jezoensis to climate change in Xiao-xing'anling Mountains, Northeast China].

Based on dendrochronological methods, we established residual chronologies of Pinus koraiensis and Picea jezoensis, with the dominant species of broadleaved Korean pine mixed forest at low altitudes chosen as the research object, to identify the key climatic factors affecting the radial growth of the two species in Xiaoxing'anling Mountains, Northeast China. The results showed that the responses of the two species to climate factors were different, and P. koraiensis was more sensitive, and hence more suitable for dendroclimatological analysis.