Last week, over 30 scientists from across the US, Canada, and as far as Germany stood on the soggy wetlands of Juneau’s Douglas Island during the third Coastal Rainforest Margins Research Network workshop. Though everyone stared down at the same moss-covered peat, the group was thinking about the ecosystem from distinct perspectives. The structure of the soil horizons, the flow and storage of water in the landscape, the chemical makeup of organic matter carried downstream, the biology of the twisted shore pine and moss communities: the soil scientists, hydrologists, biogeochemists, and ecologists each considered the field site from different lenses and scales.
Dave D’Amore, USDA Forest Service soil scientist and lead organizer of the workshop, pulled out a long probe that could have been mistaken for a collapsible tent stake and fielded guesses at the depth of the peat soil we stood on. In the end, his probe hit glacial till with a crunch at 2.8 meters. That’s nearly 3 meters of carbon-rich peat collecting and releasing water and nutrients into the ecosystem. Forested wetlands and peatlands are abundant across the region and make up a high proportion of the carbon storage for the North Pacific Coastal Temperate Rainforest (NPCTR).
With uncharacteristic March sunshine beating over our shoulders, rising temperatures and drought were at the forefront of everyone’s minds. What does drought mean in a temperate rainforest that still receives over 2 meters of rain annually in areas? What would this landscape look like under drier, warmer conditions? And how would changes to soil functioning in a warming climate impact nearshore marine environments?
Those aren’t questions that would be answered in an afternoon, nor are the many that followed in discussions throughout the week. The goal of this workshop was not to settle all the uncertainty we have around soils and material transport in this ecosystem; it was to determine the most pressing questions to ask and think ahead to how we might answer them.
The discussions centered around one overarching theme: the ways that the flow of water and nutrients connects temperate rainforests and coastal oceans. Soils play a large role in this process, storing carbon, organic matter, and water and regulating the flow of materials to streams. Factors like slope, bedrock material, soil type, and thickness alter when and what types of nutrients and sediment are exported to coastal waters. Storms, landslides, windfalls, and other disturbance events move sediment rapidly, impacting downstream ecosystems. What ends up in coastal waters has an effect on marine food webs, the acidity of coastal waters, and the global carbon budget.
Understanding the linkages between land and sea in the NPCTR starts with getting this interdisciplinary team in the same room, where scientists from different fields can collaborate to conduct research on an ecosystem-wide scale. But perhaps just as important as the diversity in areas of study was the generational spread in the group, from those with decades of research and management experience to master’s students just starting out. Early career participants had the opportunity to share and receive feedback on their work with the group in a constructive setting, as well as help set a roadmap for addressing the most critical ecological questions for future of the NPCTR.