I first learned about the NADP National Trends Network in the fall of 1994 as a graduate student beginning my research on nitrogen cycling at the Huntington Wildlife Forest in Newcomb, NY, the location of site NY20. My association with NADP has grown throughout my career from attending the science symposia, to becoming involved in committee work and now serving as the vice-chair of the Executive Committee. My work on atmospheric deposition and watershed response has consistently reinforced the value of long-term data in evaluating environmental change. Like many in the NADP community, I have come to appreciate that the strength of this program lies not only in its data, but in the people and partnerships that sustain it. From site operators collecting weekly samples in all conditions to the scientists and analysts interpreting those data, NADP is a truly collaborative scientific enterprise.

Over the past several decades, NADP has advanced our understanding of how emissions from energy production, agriculture, and other sources influence air, water, and ecosystems. These long-term records have documented important improvements in some areas while also highlighting emerging challenges, including shifts in emissions sources, evolving precipitation patterns, and changing deposition dynamics.

As our scientific questions continue to evolve, continued innovation is essential. The NADP network provides a critical foundation, offering consistent, high-quality measurements needed to detect trends, test new approaches, and inform decision-making. Building on this foundation requires creative thinking, new analytical tools, and strong collaboration across disciplines.

The theme of this year's symposium, "Thinking Outside the Bucket: Innovation in a Changing Environment," reflects this need. The presentations highlight new methods, perspectives, and applications that expand how we use NADP data to better understand atmospheric deposition and its effects.

Thank you to all of the presenters and to the broader NADP community for your continued contributions. I especially want to thank the site operators without whom the networks would not exist, they do the hard work of producing the data that are the foundation of NADP. I look forward to the discussions and collaborations that will emerge from this symposium.

Mike McHale, U.S. Geological Survey

Vice-Chair of the Executive Committee