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

ABSTRACT

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.

KEYWORDS:

• Wild harvest
• sustainable resource use
• honeybush
• tea
• harvest methods
• ash

Acknowledgments

Conversations with Christo Schutte, the harvester, were extremely insightful, and we dedicate this study to his memory. Thank you to the Biosphere Expedition volunteers for marking and measuring plants during 2017, especially Sandy Kerr, for making the aluminium numbered tags. Thanks also to Jeff and Arlene Jackman and the students of Oudeberg Nature Reserve for assisting with the marking and measuring of some plants. Thanks to Sion and Chanique for assisting with weighing of harvested plants. Thanks to the Advanced Diploma students at Nelson Mandela University for assisting with follow-up measurements in 2021, and especially Daniel Venter for completing this task. Alastair Potts edited and commented extensively on a draft version. This manuscript was substantially improved thanks to inputs from two anonymous reviewers.

Disclosure statement

This study was partially funded by the sale of honeybush harvested at this study site. Funds were used to pay and host field assistants.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/21683565.2023.2174238