Workshop: Respiration Regimes in River Networks: A cross-biome perspective; September, 2018; Valais, Switzerland

Duke University, Durham NC

Investigators

Abstract

This workshop aims to understand how and why the breakdown of organic material (heterotrophic respiration) varies over time in streams, and how and why this timing differs among streams and rivers of different sizes and in different parts of the world. Recent development of inexpensive oxygen sensors have allowed the widespread collection of multi-year continuous records of oxygen concentration, which can be used to precisely measure the timing of respiration. Organic matter may be produced in the stream by algae and other aquatic plants, or may be produced by terrestrial plants, and later be delivered to streams and rivers as falling leaves, as eroded particles of soil, or dissolved in water that flows from hillslopes to channels. These organic matter sources support the growth of animals higher in the food chain, such as insects and fish, and also provide energy for microorganisms that remove pollutants. The balance of photosynthesis and respiration in streams also influences the production of greenhouse gases such as carbon dioxide. Because organic matter can enter streams in many different ways, and because different kinds of organic matter break down at different rates, the timing of energy supply to streams also is likely to differ among streams, and to respond to many different aspects of environmental change. This award will support strengthen and broaden the scientific workforce by supporting participation of US scientists from different career stages, regions, and backgrounds in an international conference that addresses topics at the leading edge of environmental data science; will strengthen existing connections between US and international scientists and establish new ones; and will increase the use of a newly-developed online portal (StreamPULSE; data.streampulse.org) for storage, sharing, and analysis of stream photosynthesis and respiration data to an international workshop to develop and test ideas about the connections between the timing of organic matter supply and the timing of its decomposition, and how environmental change may alter these patterns. The aim of this conference is to simultaneously advance the conceptual and technical understanding of respiration and heterotrophy in streams and rivers. First, this conference will produce a conceptual model of aquatic heterotrophy that links forms, mechanisms, and timing of organic matter input to temporal patterns in respiration, drawing on case studies from intensive study of organic matter and respiration dynamics at diverse sites around the world. Second, this conference will evaluate statistical methods to improve the estimation and interpretation of respiration dynamics from continuous time series of oxygen and other variables including carbon dioxide. Finally, we will integrate these technical and conceptual advances by empirically linking the dynamics of respiration to remotely-sensed estimates of organic matter supply in forested streams. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.