Isotopic methods for non-destructive assessment of carbon dynamics in shrublands under long-term climate change manipulation

1.Long-term climate change experiments are extremely valuable for studying ecosystem responses to environmental change. Examination of the vegetation and the soil should be non-destructive to guarantee long-term research. In this paper, we review field methods using isotope techniques for assessing carbon dynamics in the plant-soil-air continuum, based on recent field experience and examples from a European climate change manipulation network. 2.Eight European semi-natural shrubland ecosystems were exposed to warming and drought manipulations. One field site was additionally exposed to elevated atmospheric CO2. We evaluate the isotope methods that were used across the network to evaluate carbon fluxes and ecosystem responses, including: 1) analysis of the naturally rare isotopes of carbon (13C and 14C) and nitrogen (15N); 2) use of in-situ pulse labelling with 13CO2, soil injections of 13C- and 15N-enriched substrates, or continuous labelling by Free Air Carbon dioxide Enrichment (FA...1. 长期气候变化实验在探究生态系统对环境变化的响应方面具有极高的科研价值。为保障长期研究的可持续推进，对植被与土壤的检测需采用非破坏性方法。本文依托近期野外研究经验与欧洲气候变化调控网络（European climate change manipulation network）的相关案例，综述了利用同位素技术（isotope techniques）评估植物-土壤-空气连续体（plant-soil-air continuum）碳动态的野外研究方法。 2. 欧洲8个半自然灌丛生态系统接受了增温与干旱调控处理，其中1个野外样地额外施加了大气CO₂浓度升高处理。本文评估了该调控网络中用于测定碳通量与生态系统响应的同位素方法，具体涵盖：1）碳（¹³C与¹⁴C）及氮（¹⁵N）的天然稀有同位素分析；2）采用¹³CO₂原位脉冲标记、¹³C与¹⁵N富集底物土壤注入法，或通过自由大气二氧化碳富集（Free Air Carbon dioxide Enrichment, FA...）开展的连续标记。