Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
Our coastal forest shows little effect from the first 10-hour exposure to salt water in June 2022 and grows normally for the rest of the year. We increased the exposure to 20 hours in June 2023 and the forest was still mostly untouched, though Tulip Poplar Tree Water was rising more slowly from the ground, which could be an early warning sign.
The situation changed after a 30-hour exposure in June 2024. Forest tulip poplar leaves begin to turn brown in mid-August, several weeks earlier than usual. By mid-September the forest canopy was bare, as if winter had set in. These changes did not occur in any nearby plots that we treated similarly, but with fresh water instead of seawater.
The initial resilience of our forests can be explained by the relatively low salt content in these estuarine waters, where freshwater rivers and salty seas mix. The rain that fell after the experiments in 2022 and 2023 washed the salt from the soil.
But after the 2024 experiment there was a major drought, so the salt settled in the soil. Long-term exposure of plants to saline soils after our 2024 experiment may have exceeded their tolerance to these conditions.
The seawater being pumped into the Southern California wildfires is full-strength, salty seawater. And there conditions It has been very dryEspecially compared to our east coast forest plots.
Obvious changes on the ground
Our research group is still trying to understand the factors that limit the tolerance of forests to saltwater and how our findings apply to other ecosystems, such as the Los Angeles region.
The leaves on the trees turning from green to brown before fall was a wonder, but the ground beneath our feet had even more surprises.
Rainwater seeping through the soil is usually clear, but about a month after the first and only 10-hour saltwater exposure in 2022, the soil water turned brown and stayed that way for two years. The brown color comes from carbon-based compounds released from dead plant material. It is a process similar to making tea.
