Matrix population models indicate that bark harvest of two medicinal plants in Uganda's Bwindi Impenetrable National Park is sustainable

A study on bark harvesting in Uganda's Bwindi Impenetrable National Park reveals that current harvest levels of two medicinal plants, Rytigynia kigeziensis and Ocotea usambarensis, are biologically sustainable. Using matrix population models and long-term data, researchers found that only a small fraction (4% for R. kigeziensis and 3% for O. usambarensis) of stems showed signs of bark harvest, mostly mild. The model predicted stable or moderately growing populations, with growth rates primarily influenced by survival probabilities. Observed population structures aligned well with the model's predictions, suggesting that estimated vital rates (growth, recruitment, and survival) accurately reflect real-world conditions. While recent harvest levels appear sustainable, ongoing monitoring through tagging, marking, and remeasuring individuals is recommended for both species to ensure long-term stability.

Stas, S. M., Langbroek, E. M., Bitariho, R., Sheil, D., & Zuidema, P. A. (2016). Matrix population models indicate that bark harvest of two medicinal plants in Uganda’s Bwindi Impenetrable National Park is sustainable. African Journal of Ecology, 55(1), 30–36. Portico. https://doi.org/10.1111/aje.12309