Panel 1. A view of the densely forested Luquillo Mountains found at the Luquillo Critical Zone Observatory (LCZO).

Panel 2. Dr. Bill McDowell stands in the forest, waves and says, “Hi, I am Dr. Bill McDowell and I lead the research conducted at the LCZO.”

Panel 3. Researchers walk through the diverse nature of the montane environment of Puerto Rico.

Panel 4. LCZO researchers study how bedrock, soils, sediments, streams, elements and microbes interact in the CZ, the region from the ground water to tree tops. A stream flows down a steep mountainside.

Panel 5. Photosynthesis in plants help to regulate the concentrations of oxygen and carbon dioxide in the atmosphere. Arrows to and from trees show that trees take in carbon dioxide and release oxygen.

Panel 6. Microbes in the soil are engaged in a constant battle for carbon from dead plant material, their main energy source. Dr. McDowell and researchers collect microbial data from the soil.

Panel 7. The rocks and mountainous landscapes at LCZO control the movement of carbon and nutrients through the streams, soils, regolith to the oceans.

Panel 8. The landscape can also affect upstream migration of aquatic organisms, like fish and shrimp.

Panel 9. The CZO is equipped with instrumentation to measure water, carbon, and nutrient budgets. Instrumentation shown includes an automatic water sampler, a stream weir, and a flux tower.

Panel 10. Dr. McDowell, among CZ researchers, says, “Understanding the Luquillo Critical Zone is important for the sustainability and protection of this unique and diverse ecosystem.”