From the first rain on the land to the second rain on a pond, a lot of rain is a natural process, says Jennifer Stoddart of the Canadian Wetlands Institute.
But, the effects of that rain can be catastrophic for ecosystems.
She says many of us are familiar with the famous saying that rain is the best thing that ever happened to a lawn.
But what if that rain comes with the potential to change the landscape?
That’s exactly what a new study from the University of Alberta has found.
A new study published in the journal Nature Climate Change says that the impacts of rain on ecosystems can be devastating for wildlife, which may not survive for long if the wetland is gone.
“It’s a really important question, because it’s not clear what is the optimal level of rainfall,” said Stoddard, the study’s lead author.
“This is a key aspect of our understanding of what’s going on in the wetlands, what kind of ecosystems we’re going to get when the rain is there and when it’s gone.”
For decades, scientists have studied the effects that rain has on wetlands, and how it affects ecosystem structure.
For example, scientists use a computer model to show how wetlands can change in response to rainfall.
The model shows that rainfall can lead to changes to the vegetation that occur in the grasslands, or in the water.
For instance, a wetland could lose its ability to hold water when it gets too wet, and then the grasses could become less productive.
“What we know is that there are some very important relationships between rainfall and water in a wet landscape,” said Dr. Kristopher L. Schulte, a water resource scientist at the University.
“And the relationship between water availability and vegetation is one that you need to take into account in order to design your landscape.”
Wetland ecosystem studies can be quite complex, so the researchers at the university wanted to create a computer simulation to better understand the effect of rain, which has been known to affect ecosystems for centuries.
They wanted to find out how rain changes ecosystem structure, and why it can have such a dramatic effect.
“We’ve been trying to understand how rain affects the structure of a wet environment, but we’re always left guessing,” said Schultes.
“For the past couple of decades, we’ve been working on this simulation, and it’s been very interesting.
We’ve seen that, while there are lots of changes in the landscape that occur with rain, we haven’t been able to understand the impacts to the species in the ecosystem.
So we wanted to have a look at what’s really going on, what might happen in a simulated wetland ecosystem and what could be done to help it survive.”
What they found surprised them.
While rain changes vegetation structure, it doesn’t necessarily cause changes to water availability.
In a simulated ecosystem, they found that the wetter the vegetation, the more water it held.
That may be because the vegetation is more water-retaining than it is hydrophobic, which means it can hold water without being flooded.
“That’s important because it means the vegetation doesn’t need to be water-rich,” said Lutz.
“The vegetation can hold more water when the rainfall is wet, because the moisture content of the water will be lower, so it can store more water and provide more water for the ecosystem.”
Lutz said they also found that vegetation with more water was better able to retain the water that was available to it, which could make it easier for animals to find food.
“So we think that the difference between a wet and a dry environment is going to be in the way that vegetation can store water, and we think it’s going to affect how water is available in the environment,” said Scott M. Smith, a research scientist at NOAA’s National Oceanic and Atmospheric Administration (NOAA).
“We think that vegetation that is more hydrophilic, like the vegetation we study, has more water available to them.
That means that the vegetation has more surface area available to water, because they can store less water.”
Luttles and Schultses work with the Canadian Grasslands Research Institute, which is funded by the Natural Sciences and Engineering Research Council of Canada (NSERC).
The study was funded by NSERC, and the research was supported by the Canadian Institute of Parks and Wildlife, and The Nature Conservancy.