The vernal equinox is upon us again and that means it is a great time to pay attention to the often-overlooked flooded areas in our forests and even small woodland areas. What some consider to be “just puddles” – many creatures call these places home and essential to their survival. Vernal pools, also known as ephemeral ponds, essentially become charged with life this time of year.
Vernal Pool Monitoring
In the coming week or so, I’ll be putting on some mud boots and heading out to check on how some local pools I’ve been monitoring are doing. Springtime visits are always an extra special sensory experience, not only to see all the creatures emerging from long winter hibernation but to hear them. Take a listen to this recording I made in 2018 when my visit luckily was during a peak wood frog chorus session.
Honestly, I could have sat there for hours just listening to them – with the frogs, birds, and sounds of the woodland a symphony of life. I did for a while, but there was also work to be done with collecting water temperatures and other site data.
Why are vernal pools important?
I have heard ecologists referring to vernal pools as keystone ecosystems. Like beavers are a keystone species in creating wetlands, vernal pools export a great deal of biomass from the aquatic to terrestrial habitat. And like coral reefs do for marine ecosystems, they introduce this great influx of energy into the food web that supports a lot of other woodland species that depend on them.
Threats to Vernal Pools
Besides various forms of pollution, I am pretty sure one of the largest threats is simply lack of awareness. These pools have varying states of wetness, and in late summer can be bone dry. (Fairy shrimp actually require the drying out of their eggs to hatch the next season). So depending on the time of year a site is visited, it could just look like a small depression with leaves in it. And given they are usually much smaller than regulated wetland minimum acres, a developer could build right over one or more.
I don’t have any solutions for that risk other than people simply being aware these habitats exist and their importance to many species. It may not prevent an area from being developed without legal protections, but it is a start.
Look Closer
The next time you are walking in the woods and see a small flooded area, stop for a moment to take a closer look. Even the simplest little bodies of water can become spawning grounds and food sources for all sorts of woodland species.
Really interesting stuff for me to be aware of for those spring hikes. Thanks!
definitely worth checking out for a closer look
I need to buy some wellies and get out there. I’ve been cursing the swamps our woodland has become since the melt but I think we’ll have to become friends.
I am guessing you’ll find some interesting things in there Joe. The path to some of these gets quite mucky, sinking over my ankles in parts.
I enjoyed the audio and video recordings, Mark. Found it to be a great way to start my morning. I wish we had more of those out here. Most are found along the Poudre River and low lying areas on the eastern plains.
I’m just glad you are aware of them. I may have to bring a thermos of coffee next time I visit and just sit.
Due to the efforts of local conservationist and enthusiastic volunteers the vernal pools in the Sourland Mountain appear to be thriving. I can hear it at night.
The last two winters in San Diego weren’t great for vernal pools but in the previous years, when we had good winter rains, I enjoyed the few of them that are accessible quite a bit. Since vernal pool habitat is so rare in Southern California (mostly on the flat mesas, which were developed early on) most of them are fenced off and not accessible to the public. Which is a good thing, to protect what’s left.
I enjoyed your audio recording and the video a lot. Just like you, I could listen to a frog concert for hours. 🙂 The Fairy Shrimp was particularly cool – I had never seen one of those before! Thanks for sharing.
I was quite lucky to be there that particular day. With some better equipment now, I hope to have less shaky video next time. I’ve been trying to get underwater footage of the Fairy Shrimp, but it’s been a challenge. Very tiny creatures.
I don’t imagine there are many of these in the deserts of CA. 🙂
There actually are fairy and/or brine shrimps in the deserts. Quite astonishing. Here in San Diego County, in Anza Borrego Desert State Park, we have Clark (Dry) Lake, which, when flooded, is home to them. I have no idea how that actually works…
Well I know their eggs need to be dried out and can remain dry for a long time (hence their use as “sea monkeys” back in the day) – just add water and they come to life. That makes me wonder what desert life takes advantage of them being there as they are pretty low on the food chain.
I’ve seen snakes going for a swim in vernal pools. 🙂
Our vernal pools here in Californias Central Valley have not materialized the past few years, for the lack of sufficient rain. They tend to get crowded with flowers when the winter is rainy. Unfortunately, we have not had a rainy winter in years.
I can only imagine the impact the long drought has had on these habitats throughout the western US.