Correlates of yield, fecundity and survival of a wild harvested Cyclopia intermedia (honeybush) population

Cyclopia intermedia (honeybush) is a plant species endemic to the fynbos biome. Wild harvested populations are used commercially to produce tea. The species is a resprouter, regrowing from underground rootstock after fires, and as such resprouts once it has been cut. However, there is concern that premature cutting may be compromising rootstock recovery. We report on an initial 400 wild plants measured and monitored under different harvest regimes, including control plants. Plants were harvested once in 2018 and regrowth and survival monitored until 2021. Here, an allometric calculation is provided based on height and stem number to estimate the harvest yield. Plants in valleys or with high surrounding vegetation had the highest yield values and potential fecundity. After harvest, an increase in mortality was correlated with plant size, being higher for smaller plants, but after two years of drought high mortality was not explained by any harvesting category nor any of the site variables, suggesting drought results in high plant mortality regardless of harvest history. The study clarifies several speculative components of harvest method, demonstrates that a complete cut rather than half cut results in better potential yield, and that an ash admixture post-harvest had no measurable impact on regrowth.

Automated summary

In this study, the harvest methods of Cyclopia intermedia were observed, and the yield was estimated based on height and stem number. The results showed that plants in valleys or with high surrounding vegetation had higher yield values and potential fecundity. Additionally, plant size was correlated with mortality rate after harvesting, with smaller plants having higher mortality. However, after two years of drought, high mortality was not influenced by harvesting category or environmental variables, indicating that drought leads to high plant mortality regardless of harvest history.