Climate change, land cover change, and overharvesting threaten a widely used medicinal plant in South Africa

Abstract

Medicinal plants contribute substantially to the well‐being of people in large parts of the world, providing traditional medicine and supporting livelihoods from trading plant parts, which is especially significant for women in low‐income communities. However, the availability of wild medicinal plants is increasingly threatened; for example, the Natal Lily (Clivia miniata), which is one of the most widely traded plants in informal medicine markets in South Africa, lost over 40% of individuals over the last 90 years. Understanding the species’ response to individual and multiple pressures is essential for prioritizing and planning conservation actions. To gain this understanding, we simulated the future range and abundance of C. miniata by coupling Species Distribution Models with a metapopulation model (RAMAS‐GIS). We contrasted scenarios of climate change (RCP2.6 vs. RCP8.5), land cover change (intensification vs. expansion), and harvesting (only juveniles vs. all life‐stages). All our scenarios pointed to continuing declines in suitable habitat and abundance by the 2050s. When acting independently, climate change, land cover change, and harvesting each reduced the projected abundance substantially, with land cover change causing the most pronounced declines. Harvesting individuals from all life stages affected the projected metapopulation size more negatively than extracting only juveniles. When the three pressures acted together, declines of suitable habitat and abundance accelerated but uncertainties were too large to identify whether pressures acted synergistically, additively, or antagonistically. Our results suggest that conservation should prioritize the protection of suitable habitat and ensure sustainable harvesting to support a viable metapopulation under realistic levels of climate change. Inadequate management of C. miniata populations in the wild will likely have negative consequences for the well‐being of people relying on this ecosystem service, and we expect there may be comparable consequences relating to other medicinal plants in different parts of the world.

Assessing the Vulnerability of Medicinal and Aromatic Plants to Climate and Land-Use Changes in a Mediterranean Biodiversity Hotspot

“…Climate change may block the ability of species to deal with land-use change, and in turn, land-use change could limit resilience to climate change [13,178]. Climate change and land use change have significant impacts on medicinal and aromatic plants, including a reduction in their diversity, abundance and growth forms, changes in their geographical distribution and habitat ranges, a decrease in the climatically suitable areas for them and detrimental effects on their secondary metabolome as a source of innovative drugs and probes for novel biochemical mechanisms and targets [13,87,[179][180][181]. Our study provides novel insights into the potential impacts of climate and land-use change on the diversity and distribution of MAPs in the Chelmos-Vouraikos National Park, a protected area and biodiversity hotspot in Greece.…”

“…These smaller conservation areas, strategically located, can provide a haven for species facing the most significant threats, ensuring their survival in the face of looming challenges [227][228][229][230]. However, other management measures become equally critical [179]. Over-harvesting of MAPs, driven by their commercial demand and their medicinal and aromatic value, is a persistent concern, and sustainable harvesting emerges as a key conservation approach for numerous wild-harvested species, considering their significant role in local economies and their enduring value to harvesters over an extended period [231][232][233][234][235][236].…”

Diversity of edible plants traded in the East Jakarta traditional markets, Indonesia

“…However, trading wild and semi-cultivated plants in traditional markets also creates problems such as sustainability and environmental protection. For example, over-harvesting can cause a decline in wild plant populations, threaten the survival of certain species, and disrupt natural ecosystems (Groner et al 2022). In addition, in some cases, illegal trading of rare or endangered plants may also occur in traditional markets.…”

Potential decline in the distribution and food provisioning services of the mopane worm (Gonimbrasia belina) in southern Africa

“…Climate change is predicted to negatively alter ecosystem services ( Mooney et al 2009 , Groner et al 2022 ). These impacts are likely to be severe for southern Africa; for instance a review by Serdeczny et al, (2017 ) predicted a significant increase in undernutrition in southern Africa under climate change, leading to greater risk of negative secondary health consequences.…”