Changes and driving factors of carbon stock in the tree layer of old-growth forests in Taiyang River Provincial Nature Reserve, Yunnan, China.

The analysis of carbon dynamics in old-growth forests helps us understand forest conservation, restoration, and regional carbon sequestration. There is still controversy over whether old-growth forests are carbon sources or sinks. Studying the carbon storage and dynamics of old-growth forests is of great significance for evaluating their carbon source and sink functions, as well as quantifying forest carbon fixation at the regional scale.

[Non-structural carbohydrates characteristics of different forest layers in monsoon broad-leaved evergreen forest in Pu'er, Yunnan Province, China].

Based on cluster analysis of species vertical stratification, the variations in concentration, allocation and seasonal dynamics of non-structural carbohydrates were investigated in a monsoon broad-leaved evergreen forest in Pu'er, Yunnan Province. The results showed that the concentrations of soluble sugar (3.9%) and nonstructural carbohydrates (NSC, 13.

[Species-area relationship at different succession stages of monsoon evergreen broad-leaved forest in south subtropical area of Yunnan Province].

Based on the investigation data of monsoon evergreen broad-leaved forest at its different succession stages (primary, CP; 15 years of succession, CF; and 30 years of succession, CT) in Pu' er of Yunnan Province, this paper studied the species-area relationship of this forest at each succession stage. It was found that in the communities at each succession stage, the number of total species, trees, shrubs, and lianas had a significant correlation with sampling area, with the area explained over 94% of the total variation. The Z value of the total species (0.