在碳和固态度的变化下,重新考虑在低温区的有氧呼吸
Anna B Tureţcaia1, Vanessa A Garayburu-Caruso2, Matthew H Kaufman2,3
1Department of Earth and Planetary Sciences, The University of Texas at Austin, Austin, Texas 78712, United States.
Environmental science & technology
|October 5, 2023
概括
低温区 (HZ) 对水生生态系统至关重要. 这项研究表明,高温区的有氧呼吸同时受到溶解有机物 (DOM) 质量和的可用性限制,根据深度而异.
科学领域:
- 环境科学 环境科学
- 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:
- 低温区 (HZ) 是地下水和地表水混合的关键接口,通过溶解有机物 (DOM) 和营养循环显著影响水生生态系统功能.
- 了解高温区内DOM代谢的空间和时间动态是必不可少的,但仍然不太了解.
研究的目的:
- 研究一项理论,即碳 (C) 和 (N) 限制之间的权衡调节了HZs.中的代谢过程.
- 为了测试在HZs中的有氧呼吸 (AR) 可以由DOM热力学和N含量共同限制的假设,由于C/N比率的微小变化.
主要方法:
- 利用大流体实验来模拟HZ条件.
- 采用连续的光极测量用于溶解氧 (DO) 监测.
- 对DOM进行了空间和时间分辨的分子分析,并从元素固态度比推断出C和N的限制.
主要成果:
- 在厘米尺度上观察到DO,DOM热力学和有机N之间的深度分层关系.
- 在浅海 (低C/N) 中,DO与DOM热力学有关.
- 在更深的HZ (更高的C/N) 中,DO与涉及有机N的生物化学反应有关,这表明了明显的限制模式.
结论:
- 在高温区的有氧呼吸是由多个相互竞争的过程调节的.
- 这些发现支持AR由DOM热力学和有机N共同限制的概念,在空间和时间上有所变化.
- 解决这些微小的变化对于改善HZ函数的机械模型预测至关重要.
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