Final answer:
Descriptive approaches involve observing and documenting characteristics of an ecosystem, while functional approaches involve manipulating variables to understand ecosystem processes.
Step-by-step explanation:
The difference between descriptive and functional approaches to answering an ecological question lies in their focus and methodology. Descriptive approaches involve observing and documenting the characteristics, patterns, and relationships within an ecosystem without manipulating variables. This approach aims to provide a detailed description of the ecosystem's structure and composition. On the other hand, functional approaches focus on understanding the processes and interactions within an ecosystem, often through experimental manipulation of variables. This approach aims to uncover the underlying mechanisms and dynamics driving ecosystem function.
For example, to study the distribution of plant species in a forest, a descriptive approach would involve mapping and documenting the species' locations. This would provide information on the spatial arrangement and diversity of plant species. In contrast, a functional approach might involve manipulating environmental factors such as light intensity or nutrient availability to investigate their effects on plant growth and competition.