Elephants and aboveground carbon stocks in a South African protected savanna

Abstract: Savanna elephants (Loxodonta africana) are known to exert transforming impacts on the vegetation. Due to these impacts, one would expect elephants to have significant effects on aboveground carbon stocks. However, we still know relatively little about the magnitude and direction of the effects of elephants on aboveground carbon stocks. Here, I combined historical data from vegetation surveys and wood density field measurements to estimate the change in aboveground carbon stocks between 1999 and 2017 in relation to different elephant impact levels in Hluhluwe-iMfolozi Park, South Africa. Despite an increasing and relatively high-density elephant population compared to other South African reserves, aboveground carbon stocks did not generally decrease over time, although we found weak evidence for a reduction in aboveground carbon stocks at extreme elephant impact levels. In addition, variation in stem diameter and elephant impact among individuals influenced the wood density of these individual for certain tree species but not for others. This demonstrates the importance of considering drivers of wood density and how their effects vary among tree species when estimating aboveground carbon stocks. Our findings support previous findings and show that elephants might not necessarily conflict with goals focused on conserving aboveground carbon stocks.