ABSTRACT

Stable isotopes in natural materials provide a powerful way to study energy flow in many systems and are widely used in fields such as archaeology, ecology, forensics, geochemistry, geology, oceanography, palaeoecology and palaeoclimatology. Based on the manner in which stable isotopes fractionate in natural systems, they allow scientists to address a wide array of research topics ranging from tracking climatic shifts, ascertaining organisms’ migratory patterns, matching organisms to their diets and/or environments, assessing food web bioenergetics, documenting ecosystem changes through time, measuring soil carbon budgets and soil microbial activity, etc. Hence, it may be a viable option to use stable isotopes to investigate stream and food web ecology with students. Students with no prior experience working with stable isotopes successfully met learning objectives by completing the requisite field and laboratory protocols, analysing data, interpreting results, and communicating their findings in a report modelled after a peer-reviewed scientific journal article. While this activity focused on food web ecology in a stream ecosystem, the method is repeatable, cost-effective, and can be modified relatively easily to evaluate food webs in virtually any other ecosystem.

摘要

天然材料中的稳定同位素为研究许多系统中的能量流动提供了强有力的方法，并广泛应用于考古学、生态学、法医学、地球化学、地质学、海洋学、古生态学和古气候学等领域。基于稳定同位素在自然系统中的分离方式，它们使科学家能够解决一系列广泛的研究课题，包括跟踪气候变化、确定生物体的迁移模式、将生物体与其饮食和/或环境相匹配、评估食物网生物能量学，记录生态系统随时间的变化，测量土壤碳收支和土壤微生物活动等。因此，使用稳定同位素与学生一起研究河流和食物网生态可能是一个可行的选择。没有使用稳定同位素工作经验的学生通过完成必要的现场和实验室协议、分析数据、解释结果以及在以同行评审的科学期刊文章为模型的报告中交流他们的发现，成功地实现了学习目标。虽然这项活动侧重于河流生态系统中的食物网生态学，但该方法是可重复的、具有成本效益的，并且可以相对容易地修改以评估几乎任何其他生态系统中的食物网。