The difference between small, controlled lab experiments and ecosystem-scale experiments primarily lies in the applicability of the results.
In small, controlled lab experiments, conditions can be meticulously controlled, which allows researchers to isolate specific variables and understand mechanisms at a fundamental level. However, the results may not always be directly applicable to real-world scenarios due to the simplified environment.
In contrast, ecosystem-scale experiments incorporate a broader range of variables and interactions that occur in natural settings, which can yield findings that are more relevant to real-world ecological dynamics, but these results might be harder to control or replicate.