Species Accumulation Curve — Ecological Sampling Simulator (2D)

Field ecologists rarely find every species on the first visit. This simulator hides a synthetic community — a chosen true number of species with a log-normal abundance distribution — and lets you survey it one individual at a time. Each draw is a genuine random pick from the true, hidden species-abundance probabilities, and the resulting species-accumulation curve is smoothed by real rarefaction: the same observed individuals are reshuffled into many independent random orders and averaged, removing the noise of any single messy field visit. A real Chao1 estimator recomputes after every draw from the count of species seen exactly once versus exactly twice, showing how statistical extrapolation closes the gap between what you've observed and the community's true hidden richness — and how the underlying abundance evenness changes how fast that gap closes.