Two identical degraded plots — a former grazed field — run in parallel on an accelerated clock. The passive plot only has its disturbance removed (grazing stops) and is left to recolonize on its own, moving through the classic succession sequence: bare soil → annual weeds → perennial grasses → shrubs → pioneer trees → mature forest. Each transition depends on the previous stage building enough soil structure and seed rain, so the whole sequence unfolds over decades. The active plot is planted directly with target tree species, which lets it skip the slow early colonization stages and close canopy in a fraction of the time — at the cost of nursery stock, labor and site prep up front.
biomass(t) = K / (1 + e^-r(t-t0))
passive: slow r, late t0 → decades to close canopy
active: fast r, early t0 → canopy within ~1-3 decades
- Time speed — simulated years advanced per real second; both plots always run on the same shared clock so the comparison stays fair.
- Biomass chart — active restoration reaches high vegetation cover much sooner; passive restoration is slower but needs no planting budget.
- Biodiversity chart — passive restoration's slower, self-selected colonization eventually supports a richer species mix; active restoration's planted stock is faster but more limited in species diversity.
- Reset — clears both plots and the charts and returns the clock to year zero.
Real-world relevance: restoration ecologists choose between passive and active approaches (or blend them) based on how degraded a site is, available budget, and how urgently the target ecosystem services are needed — this is exactly the swiftness-vs-cost trade-off visualized here.