Main content area

Soil and climate determine differential responses of soil respiration to nitrogen and acid deposition along a forest transect

Zhang, Junjun, Yang, Hao, Wang, Jinsong, Tian, Dashuan, Li, Yong, He, Nianpeng, Niu, Shuli
European journal of soil biology 2019 v.93 pp. 103097
acid deposition, air temperature, atmospheric precipitation, carbon cycle, climatic factors, cold, ecosystems, forest types, latitude, nitrogen, nitrogen content, prediction, soil acidification, soil organic carbon, soil pH, soil respiration, temperate forests, tropical forests, China
Soil respiration (RS) plays an important role in the terrestrial carbon cycle and can be affected by nitrogen deposition and soil acidification. The objective of this study was to explore the variation in RS response to nitrogen and acid deposition with forest types (subtropical forest, warm temperate forest, temperate forest and cold temperate forest). We conducted a coordinated field manipulative experiment to quantify the response of RS to nitrogen deposition and soil acidification in four different forest types in China at different latitudes along a transect from south to north. The results showed that soil inorganic nitrogen increased by 9.2%–142.9% for these four forests under nitrogen addition. Soil pH value decreased by 0.1–0.3, 0.1–0.3 and 0.2–0.4 on average across the four forests under nitrogen, acid, and nitrogen plus acid addition treatments, respectively. The response of soil respiration varied with forest types. Nitrogen addition decreased RS by 11.2%–17.8% from the subtropical to temperate forest, but increased it by 7.9% in the cold temperate forest. Acid addition reduced RS by 5.2%–16.6% on average in the four forests. Across the studied sites, the response magnitudes of RS to nitrogen addition or acid addition were all positively correlated with soil inorganic nitrogen content and soil pH value. Additionally, these changes of RS increased remarkably with latitude and soil organic carbon content, but decreased significantly with mean annual air temperature and mean annual precipitation. This study suggests that the impacts of nitrogen deposition and soil acidification on forest RS vary with different forest types and largely depend on soil and climate conditions. These factors should be considered for the simulation and prediction of ecosystem carbon cycle in forests.