The National Forest Inventory (NFI) is an important resource for estimating the national carbon (C) balance. Based on the volume, biomass, annual biomass increment and litterfall of different forest types and the 6th NFI in China, the hyperbolic relationships between them were established and net primary production (NPP) and net ecosystem production (NEP) were estimated accordingly. The results showed that the total biomass, NPP and NEP of China's forests were 5.06 Pg C, 0.68 Pg C year⁻¹ and 0.21 Pg C year⁻¹, respectively. The area-weighted mean biomass, NPP and NEP were 35.43 Mg C ha⁻¹, 4.76 Mg C ha⁻¹ year⁻¹ and 1.47 Mg C ha⁻¹ year⁻¹ and varied from 13.36 to 79.89 Mg C ha⁻¹, from 2.13 to 9.15 Mg C ha⁻¹ year⁻¹ and from −0.16 to 5.80 Mg C ha⁻¹ year⁻¹, respectively. The carbon sequestration was composed mainly of Betula and Populus forest, subtropical evergreen broadleaved forest and subtropical mixed evergreen–deciduous broadleaved forest, whereas Pinus massoniana forest and P. tabulaeformis forest were carbon sources. This study provides a method to calculate the biomass, NPP and NEP of forest ecosystems using the NFI, and may be useful for evaluating terrestrial carbon balance at regional and global levels.

The ecological value encapsulated in the term “spiritual ecology” is drawing more and more attention from ethnology, folklore, ecology, and other related disciplines. The custom of respecting and pacifying forest spirits has distinct regional and ethnic characteristics, and many scholars have discovered samples from different studies around the world. Qingyuan County, located in the mountainous region of southwest Zhejiang, is a very typical case of the practice of respecting and pacifying forest spirits. The mushroom-cultivation technology invented by the chthonic people there more than 900 years ago made this the global birthplace of artificial mushroom cultivation. The Qingyuan Forest–Mushroom Co-cultivation System (QFMCS) has been listed as an important agricultural heritage system by the Ministry of Agriculture and Rural Affairs of China, Beijing, China and a candidate project by the Food and Agriculture Organization of the United Nations, Rome, Italy for Globally Important Agricultural Heritage Systems (GIAHS). Additionally, the QFMCS is currently an important part of the Baishanzu National Park under construction. The authors made an in-depth field study in the mountainous areas of Qingyuan and used theoretical methods of ecology, anthropology, and folklore to reveal the function spiritual ecology plays in ecological conservation, forest protection, identity, and the maintenance of community interests. In the “traditional-modern” transformation of Qingyuan County, the practice of respecting and pacifying the Spirits is still being propagated, resulting in expansion and social cohesion.

In order to better understand the developmental conditions and trends of the biodiversity at agricultural heritage sites, the structure and function of the ecosystem and ecological environment in Qingtian Rice-Fish Culture System is examined in the decade since the implementation of the GIAHS project. Through the collection of historical data and sample-plot survey, this study collates the data from 2005 to 2013 related to the heritage site to evaluate the ecological benefit of the Agricultural Heritage System conservation. The results show that: (1) Since the implementation of heritage conservation, the variety of traditional rice grown at the heritage sites basically remains stable, the varieties of other crops basically remain unchanged and the varieties of fruit trees and medicinal plants have developed at faster rates. As the ecological environment at the heritage sites gradually improved, the species and richness of the biodiversity in the ecosystem have increased, especially the increasing growth of egrets and boars. (2) From 2005 to 2013 in the Fangshan Town of Qingtian County, the ecosystem areas identified as river, forest, urban and bare land have increased. The increased area of the urban ecosystem is the largest one of them, which is up to 20.30 ha; while the area of the forest ecosystem has increased to 7.29 ha. The areas of wetland, reservoir, farmland and grassland have been reduced, and the area of grassland ecosystem has been reduced the most with a reduction of 28.87 ha. From the changes in the values of the ecosystem services of different ecosystem types, the values of forest ecosystem services have achieved the most growth, reaching up to 92000 yuan yr-1 and the growth of the river and bare land ecosystem service values are not obvious. (3) Over nearly a decade, the soil nutrients and the water quality of rice fields at the heritage site have not obviously changed and the plant diseases and insect pests in the rice fields have not been aggravated. The monitoring indexes are far better than the standard values. With the great support of the local government, the production and living conditions and the living environments of farmers in the villages of the heritage sites have been greatly improved through road reconstruction, water improvement, toilet enhancements and the greening, brightness and beautification of the villages.

Researches on the ecological stoichiometry of forest vegetation at different growth stages under long-term human management activities and its driving factors will help to clarify how the limited nutrient resources are allocated at different growth stages of forests, providing a basis and suggestions for scientific cultivation of artificial forests. In subtropical China, the C:N:P stoichiometry of an ancient Torreya grandis ‘Merrillii’ community was measured in leaves, twigs, roots, soils, and soil microbes with age gradients of 0–50, 50–100, 100–300, 300–500, and more than 500 years. The results showed that the nutrient use varied with tree ages. The N and P concentrations in the leaves, twigs, and roots of T. grandis had the similar increasing trends with the increasing tree age, and the N concentrations in leaves in 0-50-year-old forests were significantly lower than those forests of other ages. Particularly, the N:P ratio of different organs was always below 10, reflecting limited N supply of plants. The soil C content increased with the increasing T. grandis forest ages while the soil microbe C showed a fluctuated trend. There was a higher correlation among the C, N and P contents and their ratios in leaves, twigs and roots of 0-50-year-old forests than that in soil microbes, but inversely at more than 500-year-old forests. The homeostasis analysis results showed that the roots and soil microbes are more indicative of soil nutrient availability. The results of redundancy analysis showed that acid phosphatase activity had the highest impact on soil microbes in 0–10 and 10–20 cm soil layers, confirming that the decomposition and transformation of P in soils is very active. Moreover, soil enzyme activity mediates the influence of soil microbes on soil N and P limitation. In summary, tree age can effect the plant–microbe–soil C:N:P stoichiometry of T. grandis forests. The growth of T. grandis is mainly restricted by N, and reasonable application of N fertilizer is needed to promote its growth.

The National Forest Inventory (NFI) is an important resource for estimating the national carbon balance (These data were unpublished data, and we could only obtain the data before 2008 through data search by now). Based on the data from sample plots, the literature, and NFI, as well as the relationships between volume, biomass, annual litterfall and soil respiration of different forest types, the net ecosystem production (NEP), changes in forest biomass carbon storage (ΔCbiomass) and non-respiratory losses (NR) of China's forests during 1999–2008 were estimated, and the forest soil carbon sequestration (ΔCsoil) was assessed according to the carbon balance principle of the forest ecosystem (ΔCsoil = NEP – NR – ΔCbiomass). The results showed that the total NEP, ΔCbiomass, NR and ΔCsoil values for China's forests were 157.530, 48.704, 31.033 and 77.793 Tg C yr–1 respectively, and average NEP, ΔCbiomass, NR, and ΔCsoil values were 101.247, 31.303, 19.945 and 49.999 g C m–2 yr–1 respectively. There were large spatial differences in forest soil carbon sequestration in different parts of China. The forest soil in Jiangxi, Hunan, Zhejiang, Fujian, Anhui, Shanxi, Shaanxi, Guangxi and Liaoning served as carbon sources and the carbon released was about 25.507 Tg C yr–1. The other 22 provinces served as carbon sinks and the average carbon sequestration by forest soil came to 103.300 Tg C yr–1. This research established a method for evaluating soil carbon sequestration by China's forests based on the NFI, which is a useful supplement to current statistical data-based studies on the forest ecosystem carbon cycle, and can promote comparable studies on forest soil carbon sequestration with consistent research methods at the regional scale.