Africa is Burning Right Now More than the Amazon and Nobody Even Knows

הועלה ב-ספטמבר 1, 2019 08:15 אחה"צ על ידי beetledude beetledude


It's important to clarify exactly where in Africa, or more specifically where in those countries, these fires are burning. Angola and Zambia both largely comprise fire-adapted savanna and woodlands where fires are a natural part of the system. Same for southern parts DRC, where the video seems to highlight most of the fires occurring in that country. Of the countries listed in the video, Tropical rain forests, which are not fire-adapted and where fires are likely to cause damage, only occur in northern DRC. How many of these fires are actually occurring in systems where they should not be occurring?

פורסם על-ידי adriaan_grobler לפני בערך 4 שנים

Adriaan makes a good point.
I just returned from a sortie by light aircraft that cut across the northern part of South Africa, eastern Botswana, western Zimbabwe, the Caprivi Strip and West and Central Zambia. Except over the central parts of Kafue National Park, there were multiple fires visible at any time during the flight. A high pressure system was dominating the subcontinent so the smoke from thousands of fires caused a haze over the entire area; even in Central Kafue, where there were no fires in a 100km radius. I'm not saying this is good or bad. I truly don't know.

The southern African floristic landscape (I refer to rural areas, not areas dominated by commercial agriculture, timber production and cityscapes) has been shaped largely by pastoralists, their fires and their cattle over the past few hundred years and also by the extinction or exclusion of wild mega herbivores in many parts. We see mostly fire-adapted savannah and woodland because the landscape has been regularly set on fire for more than a century, perhaps centuries. I guess prior to regular burning by man there were areas where natural fires occurred at decade(s)-long intervals rather than almost annually. Were regular fires always a natural part of all these systems? Perhaps large areas of fire-adapted vegetation has replaced something else?

What I do know is that the Lowveld looks very different to photographs that were taken here 90 years ago. The open grasslands have all but disappeared with the animals that thrived on them like roan, sable, tsessebe and cheetah. We still call it "savannah" but in many places it is now more shaded than vegetation types that are called woodland and even forest in neighboring countries.

Who knows through what kinds of vegetation cover the southern African "savannah" has cycled over the last 1 000 years? Do we really know what effects regular burning has brought about? Locally I see dramatic short-term changes in protected areas where burning programmes are changed and where cattle, elephant and buffalo are variously confined, excluded, regulated or reintroduced.

I guess that in deciding on management interventions like manipulation of mega-herbivore numbers and timing or preventing the burns we strive to maximize diversity or to achieve some similar conservation objective. If anyone knows how to go about that please let me know :-)

My response to all the fires I've seen recently, including a vicious one that came over the escarpment last night is frustration and sadness, but that is purely emotional.

פורסם על-ידי wynand_uys לפני בערך 4 שנים

Emeritus Profesor William Bond of UCT, an eminent fire ecologist would have something interesting to say but I do not think he is on Inaturalist. He gave a talk at the University of Cape Town three years ago in which he showed that because of global warming that savannah and bushland are advancing rapidly southwards towards the Cape in Southern Africa largely at the expense of grasslands.

One needs to be mindful that both the Amazon and the Gabonese/Congo basins have had periodic contractions and expansions during evolutionary history as evidenced by ecological and archaeological studies of soil cores and soil horizon pits showing multiple sand/charcoal layers over time.

I do agree though that the current rate of destruction of the rain forest is appalling and almost becoming irreversible in some countries such as Malaysia and Indonesia and parts of East Africa.

פורסם על-ידי charles_stirton לפני בערך 4 שנים

@beetledude I write as a complete ignoramus when it comes to the science of bushfires and only have questions. Are regular African fires healthy and useful in reducing concentrations of Greenhouse Gases like CO2 and methane? Do fires produce significant amounts of charcoal to sequester carbon for long periods ? Which produces more greenhouse gases, an area of dry grass eaten by termites ( methane producers) or the same area of grassland burnt ( producing some black carbon). Is the prevention of regular fires a cause of a rise of greenhouse gases ? Stupid questions perhaps but I would like answers from ecologiosts !

פורסם על-ידי botswanabugs לפני כמעט 4 שנים

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