The Sheans are highly adaptable as a species. They make use of whatever were available.
Riahs are not just structures for the Sheans to scale up to collect nitrogen, they also serve as housings for the Sheans. With its sheer height and thickness, there is plenty of room for each of them. Sheans make us of the size and abundance of the strands by making it hollow and make room for them to reside it. The insides are relatively simple, complementing the kind of lifestyle they lead. Housings were mostly for rest and shelter and they were all clustered together as the population of Shea is only a few thousand.
However, with the uprooting of one of the strands, some of the Sheans were starting to fear for their housing. Their worry is if they would actually be carried away with the strand when it uproots and they happen to be in it. These eventually set off some discussions about whether Shea is actually a sustainable world to be living in. After all, if all the strands were to start falling off, what would be left for them to live and hide in?
Hence, some of the more intelligent Sheans gathered and began to think about how they can make their world more sustainable…