09 Sep The Drought
If you live in New England, you are well aware that we are in the midst of one of the worst droughts in decades. Where I live in northeastern Massachusetts, we just set the record for the lowest rainfall in recorded history between June and August (under 4 inches), which has been amplified by a historically dry spring. Since January 2015, we are 18” behind where we should be in terms of precipitation. And the long-range forecast is not promising: meteorologists are predicting a warm and dry September and the potentially beneficial rains of Tropical Storm/Hurricane Hermine never materialized.
How will this drought affect our local ecosystems? It’s hard to say. Resilience is the term ecologists use to describe how quickly ecosystems can bounce back from catastrophic events. The resilience of a particular ecosystem is generally determined by the health of the ecosystem along with its level of biodiversity. Areas with a wide variety of healthy plant and animal populations tend to be more resilient; any one catastrophe is unlikely to provide a fatal blow as some species will inevitably survive based on their unique set of traits. For example, a hurricane might knock down all the mature oak and pine trees in a Massachusetts forest, but the sun-loving trees that have been held in check in the forest understory such as beeches, cherries, and maples will soon grow and replace the damaged forest canopy. Such a forest would exhibit excellent resiliency. However if a forest has a compromised understory and contains trees that have been previously damaged by disease, human interference, or drought, the forest might take much longer to recover from hurricane-inflicted damage.
Our current drought is bordering the catastrophic and will put our local ecosystems’ resilience to the test. For the most part, our native plants will survive this drought. If we were facing multiple years of drought I’d be more concerned, but our native species are genetically wired to survive these tough times. Leaves will fall earlier (and probably won’t have as robust colors), the fall flowers will be fewer, and we may see a decrease in the nut and berry crop. But the vast majority trees and plants we see around us today will survive the winter and rebound in the spring (provided the drought doesn’t persist).
However, for our aquatic animals, this summer will be potentially catastrophic. Most shallow or small wetlands in our area are completely dry. Rivers and ponds are well below their normal levels and warmer than usual. This leads to decreased dissolved oxygen levels that put even more pressure on our aquatic organisms. Frogs, salamanders, and turtles which depend on these habitats to survive are forced to wander great distances and often don’t survive the journey. Vernal pools have dried more rapidly than normal stranding frog and salamander larva that were unable to mature before losing the water they need to breathe. Our native cold-water fish such as brook trout, creek chubsucker, and fallfish will also be starved of oxygen as river waters slow, dry-up, and warm. These animals, whose numbers were already low due to disappearing habitat, could soon disappear from our local waters.
Unfortunately, humans place undue burden on our local ecosystems and reduce their resilience. The eradication of large predators has led to the robust deer population that has severely damaged our forest understory. We draw our drinking water from local wetlands and watersheds exacerbating drought conditions. There are only so many stressors our ecosystems can handle before they begin to fall apart.