Contemporary ecological design sometimes assumes reduced intervention as evidence of successful dynamism. I think the opposite is more often true in cultivated landscapes.
Without intervention, competitive exclusion can actually reduce dynamism: the vigorous things win and the garden settles into a relatively stable state. Canopies close in. Ruderals get crowded out. The most aggressive organisms decide the future for everyone.
Management and maintenance are often presented as ways of making a landscape adhere to a predetermined set of design decisions. In my experience, that can be true. It often isn’t.
Intervention often increases the number of possible futures for a garden. Weeding, pruning, propagation, selection, removal, replanting and observation continually expand possibilities for a landscape. Thoughtful intervention prevents the garden from becoming inevitable.
Inevitability happens when one process is allowed to become the primary determinant. Competitive exclusion is one example. A planting dominated by competitive native species may quickly settle into a static equilibrium. “Let nature take its course” sounds pluralistic, but any particular site may actually converge toward fewer possibilities.
That makes disturbance especially interesting. Cutting something back, opening a canopy gap, moving a seedling, dividing a colony, collecting seed, introducing another genotype aren't necessarily attempts to return the garden to some frozen original design. They can be interventions that create more possible trajectories for the landscape.
Even unintentional disturbances create new possibilities. Canopy closure, accumulated litter, browsing, drought, and disease affect a landscape’s composition. A skilled gardener works with natural processes to create more possibilities - rather than fighting them.
As a designer, I want to set up conditions in which plants create specific aesthetic and ecological effects, but leave enough freedom for adaptation and surprise. I see ongoing management as a tool that can be deployed at varying levels of intensity and involvement, depending on the conditions/goals for the project. Intervention opens more possibilities rather than allowing the site to gravitate towards inevitability.