Purpose of Review

The aim of this paper is to describe the carbon cycle in drylands in relation to the processes, factors, and causes affecting it. A specific focus is placed on both biotic and abiotic mechanisms of carbon sequestration in drylands in relation to mitigation of the anthropogenic climate change.

Recent Findings

Global dryland area is increasing along with an increase in risks of desertification, salinization, and eolian/hydrologic processes of accelerated soil erosion with strong impacts on the carbon cycle. Nonetheless, drylands contribute strongly towards the land-based sink of the atmospheric carbon dioxide through sequestration of carbon in the soil, ground water, and biomass. Thus, dryland ecosystems affect inter-annual variability in the global carbon cycle and create a negative feedback through carbon sequestration.

Summary

Global drylands, covering 66.7 M km² or 45.36% of the Earth’s land area, strongly impact the ecosystem carbon stock, contribute to the land-based carbon sink, and provide a negative feedback to the global carbon cycle. Whereas the net primary productivity is limited by the water scarcity, especially in hyper-arid and arid ecoregions, sequestration of inorganic carbon in soil and ground water is an important control of the carbon cycle. Desertification, caused by eolian and hydrologic erosion along with salinization, must be controlled and reversed to enhance carbon sequestration, achieve land degradation neutrality, and create a negative feedback. Carbon sequestration strategy recognizes “soil” as a rights holder to be protected, restored and naturally evolve.

中文翻译：

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全球旱地的碳循环

审查目的

本文的目的是描述干旱地区的碳循环与过程，影响其的因素和原因。与减轻人为气候变化有关，干旱地区碳固存的生物机制和非生物机制都受到了特别关注。

最近的发现

全球干旱地区的面积正在增加，同时沙漠化，盐碱化和加速土壤侵蚀的风沙/水文过程的风险也在增加，这对碳循环产生了重大影响。尽管如此，干旱地区通过固存土壤，地下水和生物质中的碳，对大气中二氧化碳的陆基吸收做出了重要贡献。因此，旱地生态系统影响全球碳循环中的年际变化，并通过碳固存产生负面反馈。

概要

全球干旱地区，占地66.7中号公里²或地球陆地面积的45.36％，大大地影响了生态系统的碳储量，有助于陆地碳汇，并提供一个负反馈到全球碳循环。净初级生产力受到缺水的限制，特别是在干旱和干旱的生态区，而土壤和地下水中无机碳的固存是碳循环的重要控制。由风沙和水文侵蚀以及盐碱化引起的荒漠化必须得到控制和逆转，以增强碳固存，实现土地退化的中立性并产生负面反馈。碳固存战略承认“土壤”是受保护，恢复和自然发展的权利所有者。