Each and every type of vegetation has its role in keeping ecology and environment in balance, however, how to measure this to determine its relevance in surrounding environment ?
Can you describe what you mean exactly by ambient ecology? But I presume this is a controlled environment where you can use specialized tools and protocols such as remote sensing and in particular Lidar to monitor vegetation changes (3 D).
It certainly depends on the particular species under consideration and the environment / ecosystem it is harbored in. In general, its involvement in the dynamics of local ecosystem and role it is playing gin the ecological fabric can be assessed by investigating the relationships and associations it develops with the other organisms in that system.
What I do is measure the percentage cover of each species in an area, then you can write a computer program that finds the the relationships between each species, and develop constants for each species in relationship to each other. It is very useful in being able to see the potential effects of new weeds for example, when they first get into native ecosystems. You do not include rocks in the transect data, but you do include bare soil.