When I have read and heard the presentations, I will synthesize them and raise questions about methodological, measurement, place-related, and theoretical challenges in research on perceived restorativeness, stress reduction, and other salutary effects of nature. These questions concern both the current state of the field and promising directions, such as more unified approaches to measurement, tools for capturing the dynamic, multi-sensory experience of diverse populations across time and settings, and the role of technologies such as satellite imaging linked with census and health data.
Beyond methodological issues, I ask whether, in focusing on effects, we have overlooked a basic question: What is nature? Natural environments vary widely—forests, deserts, grasslands, tundras, mountains, oceans, farm fields, gardens, invasive and indigenous vegetation, rivers, waterfalls, lakes, skies, and celestial bodies. We encounter them under different seasonal and weather conditions—sun, rain, fog, snow, storms. Which types and conditions are restorative? For example, does seeing a mountain in the distance differ in effect from climbing it, or reaching its summit in sunshine, rain, or snow, alone, with strangers, or with friends? Does meaning matter—for instance, if it is revered as a holy mountain, as Mount Fuji is in Japan?
Given consistent findings of restorative and stress-reducing effects, do we need to identify the specific stimulus properties that produce them, and how to measure these? Should we accept that "nature" is restorative in some mysterious way, or should research aim to isolate and replicate those properties? If so, it may be possible to design virtual environments that do not look like traditional natural settings yet possess the critical features that yield comparable benefits.