Terrestrial Ecosystem Services and the Recovery of Damaged Aquatic Ecosystems

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Vast areas of the water-rich Boreal Shield landscape are impacted by industrial development and are threatened by multiple stressors associated with climate change or global contaminants such as Hg. Management agencies recognize the importance of taking an “ecosystem approach” however many management programs, such as fish stocking, lake liming and stream rehabilitation efforts often pursue aquatic goals that are decoupled from the changes occurring on land. We therefore fail to take full advantage of the "ecosystem services" (e.g. nutrient provision, water polishing, contaminant retention, flood control etc.) that healthy land provides. *******My research program addresses the need to consider these land/water linkages to increase our understanding of how “healthy land=healthy water”. My students, colleagues and I focus on extremely damaged systems (e.g. mining impacted watershed near Sudbury, Canada) where sharp spatial gradients of disturbance exist. In these disturbed watersheds we are able to clearly identify how terrestrial ecosystem services operate and how they may be optimized to benefit damaged aquatic systems in the early, middle and late stages of recovery. For example, we showed how reforestation affects surface winds and lake stratification, metal retention in wetlands, and the role of terrestrial DOC as a nutrient subsidy to stimulate the entire food web (microbesfish). We have also used the latest molecular biology tools to isolate the unique microbial signature of terrestrial disturbances (fire, logging, mining and urbanization) to show how terrestrially derived dissolved organic matter can affect metabolism and reproduction of aquatic organisms exposed to sublethal levels of Cu. These results will help guide decision makers to set targets in their efforts to reduce air pollution.****In restoration ecology there are often “surprises”, for example where a serious stressor may actually exhibit a beneficial role during some stages of recovery. Our earlier finding that smelter emissions of potentially toxic Se led to reduced bioaccumulation of Hg in fish across the Sudbury landscape is a good example (Belzile et al. 2006 CJFAS). For this grant my students will be preparing for similar discoveries as they examine whether alien invasive forest insects (e.g. gypsy moth) may actually speed the formation of healthy forest soils to protect downstream aquatic systems. They will also try to discover whether various bioassessment techniques, including measures of microbial community function, can assess the effectiveness of “green treatment options” in urban /industrial watersheds. Finally they will try to identify the effects of exposure to sublethal levels of metals on fish in the final stages of system recovery, using analysis of fish gut microbiomes.***