**Acknowledgements**

This research has been supported by projects from Chongqing Basic Research and Frontier Exploration Program (cstc2018jcyjAX0187), the Fundamental Research Funds for the Central Universities (SWU116087 and XDJK2017B013), the New Star Foundation on Shaanxi Province Youth Science and Technology (2016KJXX-89), and National Natural Science Foundation of China (Nos. 41201258, 41411140035, and 41671511).

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**Author details**

and Ming-Guo Ma1

Chongqing, China

Shaanxi, China

\* †

, Xiao-Cong Zhu1†, Feng-Bao Zhang2

\*Address all correspondence to: shiweiyu@swu.edu.cn

† These authors contributed equally to this chapter.

provided the original work is properly cited.

1 Research Base of Karst Eco-Environments at Nanchuan in Chongqing of Ministry of Nature Resources and Chongqing Engineering Research Center for Remote Sensing Big Data, School of Geographical Sciences, Southwest University,

2 State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

, Kai-Bo Wang2

, Lei Deng2

Wei-Yu Shi1

*Soil Carbon Biogeochemistry in Arid and Semiarid Forests*

*DOI: http://dx.doi.org/10.5772/intechopen.87951*

*Soil Carbon Biogeochemistry in Arid and Semiarid Forests DOI: http://dx.doi.org/10.5772/intechopen.87951*

*Applied Geochemistry with Case Studies on Geological Formations, Exploration Techniques…*

important environmental factor, controlling a complex series of biochemical processes in soil respiration soil respiration rate sensitive to changes in soil temperature, soil temperature change will cause significant changes in soil respiration of terrestrial ecosystems carbon budget patterns have a significant impact [50]. Fierer et al. study have shown that with the increase of soil temperature, soil respiration rate of growth slowed, reducing sensitivity to temperature change, at lower temperatures, soil respiration mainly controlled by temperature changes [51]; when the temperature is high, soil respiration mainly affected by soil moisture and other factors. Soil moisture is a key limiting factor on soil respiration, soil moisture content in most ecosystems and soil respiration was significantly positively related to increased soil moisture will promote soil respiration [52]. Sponseller's study has shown that an increase in soil moisture accelerates the rate of soil respiration by affecting the vegetation's root metabolism and soil microbial activity [53]. After the soil temperature and moisture increase exceed a certain threshold range, microbial activity and soil permeability become lower, which will significantly inhibit soil respiration [54].

*Schematic diagram of DIC (dissolved inorganic carbon) leaching and transport in a closed arid basin: Tarim* 

In the past few decades, many studies have explored the evolution of forest soil carbon after afforestation, but there is still no unified conclusion. We still need three issues in future studies of forest soil carbon biogeochemistry in arid and semiarid regions. First, soil N dynamics and C-N interactions should be focused on for considering soil C accumulation. Second, we should note the effect of changes in soil properties on soil carbon after afforestation in soil carbon cycle, and we need to consider the ecological benefit. Third, we should identify key environmental factors

This research has been supported by projects from Chongqing Basic Research

and Frontier Exploration Program (cstc2018jcyjAX0187), the Fundamental Research Funds for the Central Universities (SWU116087 and XDJK2017B013), the New Star Foundation on Shaanxi Province Youth Science and Technology (2016KJXX-89), and National Natural Science Foundation of China (Nos. 41201258,

**5. Main conclusions and future research lines**

in soil CO2 sequestration and its influence in climate change.

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**Figure 3.**

*Basin, as an example cited from Li et al. [46].*

**Acknowledgements**

41411140035, and 41671511).
