Intermittent streams are characterized by significant periods of low to no flow, yet are also frequently subjected to flashy, high floods. Floods alter ecosystem function and result in variable successional patterns across the stream network. Yet, the timing of restored function after floods in intermittent stream networks is relatively unexplored. We measured recovery of stream ecosystem function using rates of gross primary production (GPP), ecosystem respiration (ER), net ecosystem production (NEP), and the primary production to respiration ratio (P/R) across eight locations in the Kings Creek drainage basin with differing preflood conditions (previously dry [intermittent] or flowing [perennial]) over a 30-d period following a 2-yr return interval flood. We found that all metabolic rates (GPP, ER, NEP, P/R) varied primarily by time (days since flood) and antecedent flow, but not spatial network position (i.e., drainage area). Intermittent sites exhibited high rates of ER (0.17–3.33 g dissolved oxygen [DO] m⁻² d⁻¹) following rewetting compared to perennial sites (0.03–1.17 g DO m⁻² d⁻¹), while GPP, NEP, and P/R were slower to recover and varied less between sites of differing preflood conditions. Metabolic rates were not strongly influenced by other environmental conditions. A large proportion of variation was explained by the random effect of location. Our results suggest that metabolism is temporally asynchronous and highly heterogenous across intermittent watersheds and that antecedent hydrology (drying prior to rewetting) stimulates heterotrophic activity, likely dependent on terrestrially derived organic matter and nutrient subsidies.

中文翻译：

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草原河流新陈代谢的恢复因河岸泛滥后河流网络的先前水文而异

间歇性溪流的特点是大量的低流量到无流量，但也经常遭受突然的高洪水。洪水改变了生态系统的功能，并导致整个河流网络发生变化的演替模式。然而，间歇性河流网络洪水后恢复功能的时间相对尚未探索。我们使用 Kings Creek 排水系统 8 个地点的总初级生产力 (GPP)、生态系统呼吸 (ER)、净生态系统产量 (NEP) 和初级生产力与呼吸比 (P/R) 来衡量河流生态系统功能的恢复在 2 年的回归间隔洪水之后的 30 天内，具有不同洪水前条件（以前干燥 [间歇] 或流动 [多年生]）的盆地。我们发现所有代谢率（GPP、ER、NEP、P/R) 主要随时间（洪水后的天数）和前行流量而变化，但与空间网络位置（即流域面积）无关。间歇性位点表现出较高的 ER (0.17–3.33 g 溶解氧 [DO] m^-2 d ^-1）与多年生场地（0.03-1.17 g DO m ^-2 d ^-1）相比，再润湿后，而 GPP、NEP 和 P/R 的恢复速度较慢，并且在不同洪水前条件的场地之间变化较小。代谢率不受其他环境条件的强烈影响。很大一部分变化是由位置的随机效应解释的。我们的研究结果表明，间歇性流域的新陈代谢在时间上是异步的和高度异质的，并且先前的水文（再润湿前的干燥）刺激了异养活动，可能依赖于陆地衍生的有机物和养分补贴。