The response of geophytes to continuous human foraging on the Cape south coast, South Africa and its implications for early hunter-gatherer mobility patterns

Abstract

Current ecological understanding of plants with underground storage organs (USOs) suggests they have, in general, low rates of recruitment and thus as a resource it should be rapidly exhausted, which likely had implications for hunter-gatherer mobility patterns. We focus on the resilience (defined here as the ability of species to persist after being harvested) of USOs to human foraging. Human foragers harvested all visible USO material from 19 plots spread across six Cape south coast (South Africa) vegetation types for three consecutive years (2015–2017) during the period of peak USO apparency (September–October). We expected the plots to be depleted after the first year of harvesting since the entire storage organ of the USO is removed during foraging, i.e. immediate and substantial declines from the first to the second harvest. However, over 50% of the total weight harvested in 2015 was harvested in 2016 and 2017; only after two consecutive years of harvesting, was there evidence of significantly lower yield (p = 0.034) than the first (2015) harvest. Novel emergence of new species and new individuals in year two and three buffered the decline of harvested USOs. We use our findings to make predictions on hunter-gatherer mobility patterns in this region compared to the Hadza in East Africa and the Alyawara in North Australia.

Understanding the effects of weather parameters on the population dynamics of an endangered geophyte supports monitoring efficiency

“…1): means (daily mean (T mean ), maximum (T max ) and minimum temperature (T min ), diurnal temperature range (DTR), drought index), sum (daily precipitation(P sum )), maximum and minimum (diurnal temperature range (DTR max, DTR min )) were calculated, as well as the number of frost days (D f ) and number of days with precipitation (D p ). The periods considered were: (1) early spring -peak owering period, (2) fall -owering period, (3) assimilation period of the previous year, (4) leaf growing period, (5) fall -peak assimilation period, (6) early spring -peak assimilation period, (7) period between owering and fruiting and (8) owering period. These periods were chosen as they are expected to have a main in uence on dormancy breaking (1, 2, 5), on bulb growth (3,4,6) and on reproduction (7, 8) (Nagyné 1984; Khodorova and Boitel-Conti 2013; Kashin et al 2020).…”

“…Figure 1 Main life cycle stages of C. bulbocodium in two consecutive years and periods (marked with numbers) for which weather parameters were studied: (1) early spring -peak owering period, (2) fall -owering period, (3) assimilation period of the previous year, (4) leaf growing period, (5) fall -peak assimilation period (6) early spring -peak assimilation period, (7) period between owering and fruiting and (8) owering period. For detailed description see Supplement Material Table 1.…”

Light Intensity and Growth Media Influence Growth, Nutrition, and Phytochemical Content in Trachyandra divaricata Kunth

“…It is a stout, tufted, rhizomatous perennial which produces fleshy leaves that grow up to 1 m long and a horizontal stalk that produces white to purple flowers [25]. According to ethnobotanical reports, the flower buds of this plant were eaten by the ancient Khoisan residents of South Africa in times of food scarcity [26,27]. Nowadays, the plant is underutilised, despite the increasing demands for plant-based nutrients, and there have been no studies on its nutrient profiles, pharmacological potential, and sustainable cultivation protocols developed for this species and its close relatives [19,20].…”

Human occupational intensity and palaeoecology at Klasies River from MIS 5–3: Preliminary taphonomic analyses of faunal remains from the Deacon and Wurz excavations

“…It has been suggested that the Cape Floristic Region (CFR) of the southern Cape-particularly its food resources-played an important role in human evolution in the later Pleistocene (Jerardino and Marean, 2010;Parkington, 2010;Marean, 2010, Faith, 2011Marean et al, 2014; but see Brink 2016 andWurz et al, 2018 on the important role of the interior of southern Africa). Besides highly nutritious marine resources along the coast, the CFR is rich in geophytes, which both modern and ancient people have exploited as a reliable source of high-quality carbohydrates (Marean, 2010;De Vynck J. C. et al, 2016a;Botha et al, 2019). The topography of the southern Cape is important in human development through the MSA.…”