• Jessica Evans

Spekboom: the plant we need

South Africa has been in a drought for a few years now and every time I fly home (Johannesburg) from university the ever-present cloud of smog hanging over the horizon seems to get thicker and thicker. It's almost too good to believe that there is a plant out there that could ease the burden of water shortages and filthy air - an indigenous plant no less! I'm talking about the spekboom, of course. Portulacaria afra is it's scientific name.

There is no time like the present for us to do all we can to reduce our environmental impact and there are loads of ways to do this. Having an eco-friendly garden is just one. Forget the thirsty likes of jacarandas and hibiscus and go for a more indigenous feel by adding some spekboom. Here are some of the reasons why spekboom is just fantastic.

Green house gases (like CO2 and methane) are specific types of air that keep earth warm enough to sustain life (yay!). BUT too much of this air makes the world too hot, causing landscapes to change (Atlantis vibes at this point) and weather to become more extreme (apocalypse vibes), which is really no good.

CO2 is a nasty greenhouse gas when there's too much of it and all plants take it out of the air when they photosynthesize. But not all plants were created equal, it seems. Spekboom, and other succulents, can take up a lot more CO2 than other plants. In fact, regions with a lot of spekboom can absorb a similar amount of CO2 from the air as forest ecosystems of the same size! Ecosystems containing spekboom as a dominant species can absorb 4.1 tons of carbon per hectare per year! This is because of the kind of photosynthesis it uses. In dry conditions spekboom uses crassulacean acid metabolism (CAM), which is a kind of photosynthesis that happens when there isn't lots of water. CAM photosynthesis absorbs lots of CO2.

If degraded regions (of which South Africa has many) are restored with vegetation; and if agriculture is done responsibly; and current ecosystems are preserved it's possible that 10% of the current amount of CO2 in the atmosphere could be taken up by plants and stored by 2050. It just goes to show the power plants have when it comes to this stuff.

So spekboom cleans our air very efficiently, but guess what?! It's also super water-wise! In fact, the less you water it, the better! Spekboom in wetter environments takes up less CO2 than in drier parts. That's because spekboom is a facultative CAM plant, meaning it only uses CAM photosynthesis when conditions are not favourable.

Plants absorb atmospheric CO2 by opening tiny holes in their leaves called stomata. The compromise is that when it's hot, water can leave the plant through these stomata. When using CAM photosynthesis, a plant only takes in CO2 at night to avoid losing water during the day. So any water you give your spekboom won't be lost to the environment during hot days, making it even more economical when it comes to water.

There are lots of amazing plants as good, if not better than the spekboom. Examples of full-time CAM plants (CAM is what makes them amazing) include the pineapple, crassulas, most cacti, orchids, agave, and aloes.

But spekboom is a favourite of mine, not only because it's great for the environment, but also because of it's quirks! It, for some reason, was named "bacon tree" which I think is funny; it's leaves are little and cute and chunky; and they taste like sour grapes (please don't go around sampling random foliage unless you know what it is). If for nothing else, those three reasons alone make spekboom a fun thing to have around.

#drought #spekboom #CO2 #greenhousegases #waterwise #CAM #photosynthesis #emissions

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