Milanovich Joseph R, Hopton Matthew E
United States Environmental Protection Agency, Office of Research and Development, Sustainable Technology Division, National Risk Management Research Laboratory, Sustainable Environments Branch, Cincinnati, Ohio, USA.
Integr Zool. 2014 Nov;9(5):613-22. doi: 10.1111/1749-4877.12114.
Ecological stoichiometry provides a framework to investigate an organism's relationship to nutrient cycles. An organism's stoichiometry is thought to constrain its contribution to nutrient cycles (recycling or storage), and to limit its growth and reproduction. Factors that influence the stoichiometry of a consumer are largely unstudied, but what is known is that consumer stoichiometry is influenced by the elemental requirements of the consumer (e.g. for growth, reproduction and cell maintenance) and the availability of elements. We examined whole-body stoichiometry of larval southern two-lined salamanders (Eurycea cirrigera) and described the influence of location, body size, stoichiometry of diet items, and environmental nutrient supply on whole-body stoichiometry. Mean composition of phosphorous was 2.6%, nitrogen was 11.3%, and carbon was 39.6%, which are similar for other aquatic vertebrate taxa. The most significant predictor of whole-body stoichiometry was the site where the samples were collected, which was significant for each nutrient and nutrient ratio. Body size and stoichiometry of diet items were also predictors of Eurycea cirrigera stoichiometry. Our study suggests that spatial differences in environmental nutrient supply have a stronger influence on consumer whole-body stoichiometry among similar-sized larvae compared to life history traits, such as body size or diet.
生态化学计量学提供了一个框架，用于研究生物体与养分循环的关系。生物体的化学计量学被认为会限制其对养分循环（再循环或储存）的贡献，并限制其生长和繁殖。影响消费者化学计量学的因素在很大程度上尚未得到研究，但已知的是，消费者的化学计量学受消费者的元素需求（例如用于生长、繁殖和细胞维持）以及元素的可利用性影响。我们研究了南部双线蝾螈（Eurycea cirrigera）幼体的全身化学计量学，并描述了位置、体型、食物项目的化学计量学以及环境养分供应对全身化学计量学的影响。磷的平均组成是2.6%，氮是11.3%，碳是39.6%，这与其他水生脊椎动物类群相似。全身化学计量学最显著的预测因子是采集样本的地点，这对每种养分和养分比例都具有显著性。体型和食物项目的化学计量学也是南部双线蝾螈化学计量学的预测因子。我们的研究表明，与体型或饮食等生活史特征相比，环境养分供应的空间差异对相似大小幼体的消费者全身化学计量学影响更大。
