What has the SSCZO team focused on? 1.Regolith: How do topographic variability, moisture, weathering, and soil formation control the thickness and development of regolith? How do regolith properties control the cycling of water, energy, and CO 2 ? 2.Vegetation: How do climate and regolith properties control the distribution, density, and activity of vegetation? How does vegetation control the cycling of water, energy, and CO 2 ? 3.Landscape biogeochemistry: How do landscape patterns of climate, regolith, and vegetation control carbon and nutrient cycling? 4.Landscape hydrology: How do landscape patterns of climate, regolith, and vegetation control soil moisture, ET and streamflow?

Science vision, goals and anticipated outcomes A.What regulates the evolution of the CZ? B.Research questions 1.How do regolith properties and process of formation vary over 10 m to 100 km scales? 2.How do physics, chemistry, and biology interact to influence Critical Zone function over instantaneous to decadal timescales? 3.How quickly do regolith properties change in response to altered climate and biota? 4.How do regolith development and properties control, limit or modulate effects of climate change, forest management or disturbance on hydrology, biogeochemistry and ecology? 5.What measurements of the critical zone at appropriate spatial and temporal scales, using cutting-edge technology, can best advance knowledge of the Critical Zone? C.Implications for CZ sustainability

Implementation plan and research activities 1.Core measurements 2.Drilling, sampling, and imaging regolith: 3.Controls on weathering and regolith formation 4.Relationship between elevation/climate and carbon and water exchanges 5.Relationship between elevation/climate and nutrient cycling 6.Effect of forest management on water and nutrient cycling 7.Synthesis, earth-system modeling and prediction

Reviewer_comments 1.Although the work appeals to the idea that the gradients at the site offer the opportunity of a space-time transformation, this idea is not particularly clear. The work might be strengthened by a synthesis effort to clarify/elaborate the ingredients, nuances and caveats of this proposed transformation as manifest in the CZ structure and associated vegetation structure, the outcome of which might provide guidelines on how to fully interpret the co-existing gradients at the site for use in forecasting. Conceptual model paper 2. Missing from the team (and the entire proposal) is expertise and application of soil microbiology. 3. Another deficiency is the absence of a geologist with expertise in structure and petrology of the region. 4. The proposal mentions hotspots for incorporating in watershed scale descriptions. Unfortunately this is never tied in with the rest of the proposal (even the measurements) so this intriguing idea is not really built into the field measurements or the modeling. 5.Similarly the model development or RHESSys and PIHM does not seem to be well integrated with the measurement and monitoring efforts.

Reviewer_comments (cont.) 6.There is a lack of explicit attention to the potential outcomes of forest management and forest disturbance (fire), which is a missed opportunity. 7.Connection to other existing research networks was not articulated (USGS gauging stations, NOAA met stations, FLUXNET, NEON, LTERs). 8.predicting the impact of climate change on the availability of water and other ecosystem services … However, this aspect of societal impact is not well developed and better connections with pertinent state and federal agencies and other stakeholders could be beneficial. 9.The likelihood for up-scaling models generated in this CZO is minimal given the explanations presented. There just is not enough discussion and explanation of the steps involved to have confidence that this would have a favorable outcome.