is a computer model of every tree in the project area. We build it from the forest owner's own inventory data, which owners maintain anyway for tax purposes, and we harmonise that data so our simulation software can work with it. For each stand we know the species mix, the average age, and how well different species have grown on that specific site over the past hundred years. From that, the simulation generates individual trees, each with its own species, size, and precise location. Once the twin exists, we run it forward in time, usually over thirty years, in five-year steps. In each step, trees grow, some die from climate stress, some get harvested or thinned, and new ones come in through planting or natural regeneration. The growth functions, mortality models, and regeneration dynamics behind these steps all come from peer-reviewed forest science, built on decades of published research on how specific species behave under specific site conditions. We always run two scenarios in parallel: a baseline that reflects what standard practice in neighbouring forests would produce, and a project scenario with the changed management plan. The delta between the two is what we can issue as credits. The contrast with most forest carbon projects comes down to the unit of measurement. Many projects rely on sample plots, area averages, or fixed expansion factors. That works for broad estimates, but it smooths over everything that makes a specific forest behave the way it does.
The Pina Earth simulation
works at single-tree resolution, which means it can capture species interactions, how a thinning in one period affects the growing conditions for the generation underneath, and how changes in species mix compound over decades. Combined with the scientific foundation of the underlying equations, that level of detail is what gives us the transparency to show buyers exactly where the climate benefit comes from and how it develops over time.