Effects of soil nutrients and stand structure on aboveground net primary productivity of oak secondary forests in the forest–steppe transition zone of Loess Plateau, China

• Published in: Canadian journal of forest research Vol. 51; no. 9; pp. 1208 - 1217
• Main Authors: Sun, Meimei, Zhai, Bo-Chao, Chen, Qiu-Wen, Li, Guoqing, Tateno, Ryunosuke, Yamanaka, Norikazu, Du, Sheng
• Format: Journal Article
• Language: English
• Published: 1840 Woodward Drive, Suite 1, Ottawa, ON K2C 0P7 NRC Research Press 01.09.2021; Canadian Science Publishing NRC Research Press
• Subjects: aboveground net primary productivity (ANPP); Canada; chênaie; dryland; Environmental aspects; Forest ecosystems; Forest productivity; Forests; Forests and forestry; Litter fall; Loess Plateau; Multivariate statistical analysis; Net Primary Productivity; Nutrients; nutriments du sol; Oak; oak forest; Plateau de Loess; Primary productivity (Biology); Productivity; productivité primaire nette aérienne (PPNA); Quercus liaotungensis; Soil investigations; Soil nutrients; Soil structure; Soils; Stand structure; Steppes; structure du peuplement; terre sèche; Terrestrial ecosystems; Transition zone; Canada; China; Loess Plateau
• ISSN: 0045-5067; 1208-6037
• DOI: 10.1139/cjfr-2020-0459

Liaodong oak (Quercus liaotungensis Koidz.) dominated forests contribute to the few natural forest ecosystems in the semiarid Loess Plateau region in China. This study investigated the influence of soil nutrients and stand structure on aboveground net primary productivity (ANPP) in the oak communities. We aimed to understand the major factors and their possible pathways that determine the ecosystem productivity. The biomass and the ANPP were estimated using plot surveys and litterfall collection in fixed plots. Linear regressions and structural equation models were used to evaluate the relationships among soil nutrients, stand structure (including vertical and horizontal structure), and ANPP. The results showed that the effect sizes of soil nutrients on ANPP and leaf production were near 60% and 70%, respectively. More than 70% of the variation in woody production was explained by stand structure, while litterfall production was largely dependent on stand vertical structure with effect size of 64%. The effect of soil nutrients on stand structural indices was detected only in the case of the vertical structure. The results suggested that soil nutrients could affect forest productivity both directly and indirectly in coordination with stand vertical structure, and that the effect of stand structure was limited in these communities.