全球循环的变化发生在全新世纪时代
Kendra K McLauchlan1, Joseph J Williams, Joseph M Craine
1Department of Geography, Kansas State University, Manhattan, Kansas 66506, USA. mclauch@ksu.edu
Nature
|March 23, 2013
概括
全球生态系统可能缓冲不断增加的污染. 过去的数据显示,在最后一个冰河时代,的可用性正在下降,但最近的人类影响没有显示出一致的全球变化,这表明二氧化碳的吸收可能会抵消的流入.
科学领域:
- 地球系统科学 地球系统科学
- 生态生态学 生态生态学
- 生物地质化学生物地质化学
背景情况:
- 人类活动在全球范围内显著增加了活性水平,引发了人们对生物圈吸收这种涌入的能力的担忧.
- 了解过去的循环对环境变化的反应,对于预测未来的生态系统行为至关重要.
研究的目的:
- 为了研究陆地生态系统如何响应和碳循环的变化,在世-全新世过渡期间.
- 评估最近人为气增加和二氧化碳上升对全球气循环的影响.
主要方法:
- 在跨越六大洲的86个湖泊沉积物记录中分析稳定的同位素比率 (δ(15) N.
- 同位素数据与古气候记录,大气二氧化碳度和陆地碳积累估计数据的比较.
主要成果:
- 沉积物 δ(15) N 值从 15,000 年大幅下降到 7,056 年,这表明在世-全新世过渡期间陆地的可用性正在下降.
- 这种气可用性的下降与大气中二氧化碳和陆地碳储存的增加有关.
- 在过去500年中,尽管人为投入量增加,但没有观察到沉积 δ(15) N 的一致全球趋势.
结论:
- 在上一次脱冰期间,陆地生态系统经历了气可用性的下降,这与二氧化碳和碳封存的增加相吻合.
- 现代大气二氧化碳和生物圈碳吸收的增加可能会抵消最近在某些生态系统中的人类反应丰富.
- 生物圈对当前的污染的反应是复杂的,并可能因同时发生的碳循环变化而受到缓解.
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