#05 2023

Raging fire leaves path of destruction in the arid lands

By Tshililo Ramaswiela, Field Technician, Arid Lands Node and Murunwa Mathoho, Student, Sol Plaatje University

In recent weeks raging veld fires caused havoc across parts of the Northern Cape, with weather conditions hampering firefighting efforts. The areas most affected include Daniëlskuil, Kimberley, Delportshoop, Warrenton and Olifantshoek. 

It was a perfect storm – hot, dry and windy conditions made it nearly impossible to put out the flames. The runaway fire left a trail of destruction, destroying properties, livestock and thousands of hectares of grazing land. Scores of animals burnt to death, and some had to be euthanised. Several houses and infrastructure were gutted.

Woody plant mortality – Vachellia erioloba, the keystone species in the arid savanna, on fire (Photos: Tshililo Ramaswiela)

Fires in the region are becoming more frequent and more severe, largely due to very dry winter months coupled with strong winds experienced in spring. In the Kimberley area there were major fires in 2019, 2021 and September this year. The arid savanna is characterised by only a few tree components and these fires have far-reaching impacts on the natural biota and the demography of woody species.

Number of live woody species before and after fire (Source: Murunwa Mathoho)

Differences in abundance mean of common grass species before and after fire (Source: Murunwa Mathoho)

An honours project conducted by Murunwa Mathoho from Sol Plaatje University post 2021, shows how fires influence vegetation dynamics at Benfontein Nature Reserve. The Socio-Ecological Observatory for Southern African Woodlands (SEASOW) plots were resurveyed after the incidence of fire to assess the mortality of woody species, and especially the keystone species – camel thorn (Vachellia erioloba). Fire remains the biggest threat to this slow-growing, extremely hardy and drought-tolerant tree, a protected species in South Africa.

Differences in marginal biomass means of dominant grass species before and after fire (Source: Murunwa Mathoho)

The mean difference in number of multiple stems of woody vegetation before and after fire (Source: Murunwa Mathoho)

Damage to instruments  

The fire severely damaged SAEON’s weather monitoring instruments. The cost to replace the damaged infrastructure is immense. The weather station and flux tower were heavily affected, and the soil moisture logger was destroyed. Despite the extra precautionary measures put in place to protect our instruments, the risk is never far from the surface.

It is always a tricky exercise to determine the source of these fires, but we plan to clear a much bigger radius around our instruments in the very near future to prevent damage from ambient temperatures.

The fire severely damaged SAEON’s weather station and flux tower at Benfontein Nature Reserve and the soil moisture logger (right) was destroyed (Photos: Tshililo Ramaswiela)