The few measurements made indicate that from this perspective, it is a harsh environment. The paradox comes when you look at the plants. There is an abundance of species and many appear to be thriving, even some quite close to the sulfur vents. Admittedly, many of the plants are stunted. That gives a hint that something is limiting the root growth.
Soil acidity is a likely candidate.
Take time to examine the distribution, abundance and general health of the plants in this area and you'll see how well adapted the plants are to this type of environment. It is clear that we need more environmental measurements if we are to sort out exactly what is happening here. Environment Elevation is about 4,000 ft. Rainfall and air temperature will closely match that recorded at HVNP Park Headquarters. Plant Species Checklist Click the following links for the type of checklist that you want.