What does the term "stand symptoms" refer to?

The term "stand symptoms" is best understood as indicators observable from a distance, which is encapsulated by the correct answer. This phrase typically refers to the visible signs of plant health or distress that can be detected without requiring close examination. When assessing the overall health of a plant population or lawn area, these symptoms provide immediate, recognizable cues that can guide further investigation or treatment. For example, changes in color, wilting, or patchy growth might be readily apparent when looking across a landscape, signaling the need for a deeper analysis of the underlying issues affecting the plants.

The other options focus on aspects that do not align with the standard definition of "stand symptoms." For instance, visible symptoms at the cellular level tend to be microscopic and thus not suitable for observation from a distance. Symptoms found only in specific species may indicate unique conditions affecting certain plants but do not encompass the broader field observations that "stand symptoms" covers. Lastly, symptoms that change with varying temperatures can be relevant to plant health, but they do not directly define what "stand symptoms" are, which is more about general visible indicators rather than their variability with environmental factors.