Drivers of global lake productivity
In an age of unprecedented global change, it is more important than ever for limnologists to refine our understanding of ecological processes in order to make predictions of freshwater systems will function into the future. Aquatic ecosystems are subjected to multiple concurrent stressors (e.g., warming, changing precipitation regimes, and associated nutrient and organic matter loads), which is affecting lake primary production with cascading effects through the aquatic food web.
In recent years, there has been a revolution in our understanding of limits and controls on lake primary production, but there has been little work done to test newly developed theory in a globally distributed set of lakes. I'm currently working with Dr. Chris Solomon, Dr. Stuart Jones, collaborators within the GLEON network to test the framework proposed by Kelly et al. (2018) which considers how variation in the nutrient stoichiometry of loads and lake size influence the light environment and nutrient availability in lakes, two factors that ultimately influence gross primary production in lakes. |
How does hydrologic setting influence lake metabolism?
While ecosystem scientists know a lot about what structures long-term, average (“equilibrium”) metabolism across broad spatial gradients, we have thought less about temporal variation and the interaction between space and time. How does the template of hydrologic setting dictate temporal variation in metabolism? Our paper is now published in Ecosystems. You can also check out my research talk from ASLO 2021 which summarizes the work.
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Littoral greening of clear lakes: the mystery of benthic filamentous algal blooms
Over the last few years, I have been involved in a series of working groups of researchers and natural resource managers who have united around the theme of understanding the proliferation of filamentous algal blooms (FABs), emerging phenomenon impacting seemingly pristine lakes around the globe. Initially the workshops I helped organize were limited to mountain lake limnologists, but we eventually expanded our reach to scientists who work on some of the world's largest lakes (e.g., Lake Tahoe, Lake Baikal, Lake Taupo).
One outcome of our group was the synthesis of the drivers of FABs in clear-water lake. The environmental stressors leading to FABs are diverse, ranging from direct and localized (e.g., point source nutrient pollution, non-native species introductions) to indirect and regional or even global (e.g., atmospheric nutrient deposition, climate change). While the stimulus that leads to FABS may differ across locations and conditions, the responses converge to produce a proliferation of FABs in lakes traditionally viewed as relatively pristine. To advance our understanding of FABs standardized monitoring approaches need to be implemented to assess the spatiotemporal variation in littoral zone attached algae. To that end, I co-authored a methodological review paper with a group of early-career scientists where we collated periphyton and groundwater sampling and modeling techniques, with the hope of motivating researchers and managers to integrate these techniques into their programs. |