What the heck are mangroves? Not a place where we grow man trees; that would be horrifying. 

Mangroves are funky looking stilt-rooted trees that grow where most other trees can’t; in saltwater. 

They are massively important to us and our ecosystem; they store huge amounts of carbon, support nurseries for a wide variety of commercially important fish species, and protect coastal areas from storm damage.

In a new project, scientists attempted to manufacture “synthetic mangroves” to figure out how the plants were taking in saltwater from their roots, turning it to freshwater, and pumping it to their leaves. 

They discovered that the pressure difference between the leaves and the rest of the tree acts like a straw, pulling water through up from the roots and stem. A series of membranes located in the roots filter out the salt, allowing the fresh water to flow up to the leaves, where photosynthesis occurs. 

So, can man-made-mangroves solve the world’s lack of fresh water? 

Not exactly. The amount of energy required is far too high for the project to be used at large scale. 

However, while designing the synthetic mangroves, scientists came up with another brilliant use for them; incorporating them into the design of cities to make buildings more resilient in the face of storm surges.

The team said the technology can be used to design buildings that soak up excess groundwater and evaporate it from the walls and roofs. Just like the mangroves, the buildings would use a pressure difference to soak up water in the event of a flood or storm surge. 

We’re basically talking about a sponge city, without the smell, and mold. 

As storm surges and flooding incidents increase in frequency, projects like this one represent a path forward for major coastal cities. Plus, sponge city is kind of catchy…

Know an engineer or city dweller? Share sponge city with them.