Physical and chemical constraints on emergent aquatic ecosystem metabolism

Alpine glacial loss is resulting in the rapid change and even emergence of downstream lakes; however, little is known about the processes regulating development in these new ecosystems. The unique properties of glacial meltwater impose physical and chemical constraints on lake ecosystem processes, but the degree to which these constraints interact or relax as glaciers recede is not well understood. The nature of these constraints have direct consequences for the fundamental ecological characteristics of the ecosystem. For example, glacial inputs rich in sediment may reduce light thereby limiting primary production, whereas glacial inputs rich nutrients may promote primary production. As these inputs fade, the response of lake biota determine the corresponding changes in biogeochemical cycling. Understanding the relative importance of glacial inputs to the metabolism of emerging aquatic ecosystems may help preserve them and build a framework to predict their trajectory of ecosystem development and future ecological state. In addition, aquatic systems will likely shift from net autotrophic carbon sinks to net heterotrophic carbon sources as glaciers disappear and vegetation colonizes alpine catchments

Reconciling carbon‐cycle processes from ecosystem to global scales

International audienc

Key rules of life and the fading cryosphere: Impacts in alpine lakes and streams

Alpine regions are changing rapidly due to loss of snow and ice in response to ongoing climate change. While studies have documented ecological responses in alpine lakes and streams to these changes, our ability to predict such outcomes is limited. We propose that the application of fundamental rules of life can help develop necessary predictive frameworks. We focus on four key rules of life and their interactions: the temperature dependence of biotic processes from enzymes to evolution; the wavelength dependence of the effects of solar radiation on biological and ecological processes; the ramifications of the non-arbitrary elemental stoichiometry of life; and maximization of limiting resource use efficiency across scales. As the cryosphere melts and thaws, alpine lakes and streams will experience major changes in temperature regimes, absolute and relative inputs of solar radiation in ultraviolet and photosynthetically active radiation, and relative supplies of resources (e.g., carbon, nitrogen, and phosphorus), leading to nonlinear and interactive effects on particular biota, as well as on community and ecosystem properties. We propose that applying these key rules of life to cryosphere-influenced ecosystems will reduce uncertainties about the impacts of global change and help develop an integrated global view of rapidly changing alpine environments. However, doing so will require intensive interdisciplinary collaboration and international cooperation. More broadly, the alpine cryosphere is an example of a system where improving our understanding of mechanistic underpinnings of living systems might transform our ability to predict and mitigate the impacts of ongoing global change across the daunting scope of diversity in Earth's biota and environments