Temperature response of respiration and respiratory quotients of 16 co-occurring temperate tree species
Temperature response of respiration and respiratory quotients of 16 co-occurring temperate tree species
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16种共生温带树种呼吸和呼吸商的温度响应
作者：
A. E. Patterson;Rachel Arkebauer;Crystal Quallo;M. Heskel;Ximeng Li;N. Boelman;K. Griffin
由于大规模农业、木材采伐和火灾干扰的历史性下降，美国东北部的森林是全球增长最快的陆地碳汇之一。然而，随着气温升高，树种分布范围的变化正在改变森林群落的组成和碳动态。在这里，我们专注于呼吸，这是一个强烈依赖于温度和物种的生理过程。我们专门研究了呼吸（R; CO2释放）对温度的反应，在10个阔叶树和6个针叶树物种，以及呼吸商（RQ; CO2释放的O2消耗的比率）的9个阔叶树物种，共同出现在哈德逊高地地区的纽约，美国。这些生理测量和相关的叶性状之间的关系也进行了探讨。在20 °C的呼吸速率是71%，高出北部范围的阔叶树种相比，中部和南部范围的物种。相比之下，在20 °C时，北部针叶树的呼吸速率比中部针叶树低12%。温度从15 °C升高到35 °C时，阔叶树种的RQ增加了14%。当RQ值汇集在温度，北方范围的阔叶树种有12%和9%的RQ值低于中央，南方范围的物种，分别表明依赖替代（非碳水化合物）基板，以满足呼吸需求。Pearson相关分析的叶性状和呼吸之间的相关性较强，叶氮，叶质量面积和R阔叶和针叶树种。我们的研究结果阐明了叶性状与树木生理的关系，并揭示了不同分布范围的物种的各种形式和功能策略。再加上预测的范围分布变化和物种更替，这可能会降低东北森林的碳储存潜力。
The forests of the northeastern US are globally, one of the fastest growing terrestrial carbon sinks due to historical declines in large-scale agriculture, timber harvesting and fire disturbance. However, shifting range distributions of tree species with warming air temperatures are altering forest community composition and carbon dynamics. Here, we focus on respiration, a physiological process that is strongly temperature and species dependent. We specifically examined the response of respiration (R; CO2 release) to temperature in 10 broadleaved and six conifer species, as well as the respiratory quotient (RQ; ratio of CO2 released to O2 consumed) of nine broadleaved species that co-occur in the Hudson Highlands Region of New York, USA. The relationships between these physiological measurements and associated leaf traits were also explored. The rates of respiration at 20 °C were 71% higher in northern-ranged broadleaved species when compared with both central- and southern-ranged species. In contrast, the rates of respiration at 20 °C in northern-ranged conifers were 12% lower than in central-ranged conifers. The RQ of broadleaved species increased by 14% as temperatures increased from 15 °C to 35 °C. When RQ values were pooled across temperature, northern-ranged broadleaved species had 12% and 9% lower RQ values than central, and southern-ranged species, respectively, suggesting a reliance on alternative (non-carbohydrate) substrates to fulfill respiratory demands. A Pearson correlation analysis of leaf traits and respiration revealed strong correlations between leaf nitrogen, leaf mass area and R for both broadleaved and conifer species. Our results elucidate leaf trait relationships with tree physiology and reveal the various form and function strategies for species from differing range distributions. Compounded with predicted range distribution shifts and species replacement, this may reduce the carbon storage potential of northeast forests.