Estimating autotrophic respiration in streams using daily metabolism data
Estimating autotrophic respiration in streams using daily metabolism data
复制标题
使用每日代谢数据估计溪流中的自养呼吸
DOI：
10.1899/12-147.1
复制
发表时间：
2013
影响因子：
1.4
通讯作者：
J. Beaulieu
中科院分区：
文献类型：
--
作者：
R. Hall;J. Beaulieu
抽象。总初级生产力（GPP）的一部分，立即呼吸的自养生物和它们密切相关的异养生物（ARf）是未知的。这个值对于计算食物网的自养基础是必要的，这需要知道可用于食草动物的生产。ARf对于估计异养呼吸（HR）也是必要的，而计算溪流和河流中的C螺旋也需要该呼吸。我们提出了一种方法来估计ARf从每日代谢数据使用GPP和90%分位数的生态系统呼吸（ER）之间的分位数回归。我们推断，自养呼吸代表ER在任何一天的下限，并使用分位数回归估计ER的较低分位数与GPP的关系。我们研究了这种方法与模拟建模和分位数回归估计连续GPP和ER从>20流的应用。模拟模型表明，ARf的低不确定性估计需要每日GPP的大变化。HR和GPP之间的协方差，如果过程是温度控制的，可能会观察到ARf的有偏估计值。ARf的季节性估计值对于ARf作为GPP函数的每日变化是稳健的。根据先前发表的溪流每日代谢估计值计算的急性参考因子平均值为0.44（SD = 0.19），溪流之间差异很大。 该值高于大多数生理测量值，可能是因为藻类的光限制以及与每日GPP密切相关的HR。有多少ARf是从藻类呼吸与密切相关的异养呼吸是未知的，但我们建议的值（1 - ARf）GPP代表的C可供动物的量。
Abstract. The fraction of gross primary production (GPP) that is immediately respired by autotrophs and their closely associated heterotrophs (ARf) is unknown. This value is necessary to calculate the autotrophic base of food webs, which requires knowing production available for grazers. ARf is also necessary for estimating heterotrophic respiration (HR) which is needed to calculate C spiraling in streams and rivers. We suggest a way to estimate ARf from daily metabolism data using quantile regression between GPP and 90% quantile of ecosystem respiration (ER). We reasoned that autotrophic respiration represents the lower limit for ER on any one day and used quantile regression to estimate the relationship of the lower quantile of ER with respect to GPP. We examined this approach with simulation modeling and application of quantile regression to estimates of continuous GPP and ER from >20 streams. Simulation modeling showed that low-uncertainty estimates of ARf required large variation in daily GPP. Covariance between HR and GPP, which might be observed if the processes were temperature controlled, biased estimates of ARf. Seasonal estimates of ARf were robust to daily variation in ARf as a function of GPP. ARf calculated from previously published estimates of daily metabolism from streams averaged 0.44 (SD = 0.19) with high variation among streams. This value is higher than most physiological measurements, probably because of light limitation of algae and from HR closely associated with daily GPP. How much of ARf was from algal respiration vs closely associated heterotrophic respiration is not known, but we suggest that the value (1 – ARf)GPP represents the amount of C available to animals.