Today I did a garden maintenance job. It was a bit of an interesting one, involving a large Acacia argyrophylla (beautiful species, worth a look as a feature in sandy soils) that had become infested with caterpillars. A few caterpillars here and there don't make me bat an eyelid. Want butterflies? You have to have caterpillars. But this was taking things to the extreme; the top half of the plant had been eaten, leaving bare branches, and the rest of it was under imminent threat.
Normally in this sort of a situation, where an insect is in overabundance, a predator will come along and have a bit of fun correcting things. With these caterpillars I would have expected the local bird life to have noticed and have had a little nibble, but they hadn't. I tried to figure out why.
The first suspect was the christmas light display still in the bush, running on mini solar panels. Was this keeping the birds away? I was told it wasn't turned on. The next suspect was the horrid plastic owl on the neighbour's roof. There were no birds in the neighbour's garden, or in the gardens on either side, so it became the prime suspect.
By removing a predator from the food chain, a species had become overabundant. Because of this, it was destroying its own food source, which was also potential habitat for a number of other species. Take out one piece of an interconnected whole and the whole thing could collapse, in less than immediately obvious ways.
Another little piece of interconnectedness I was thinking about today regards the recent and extremely controversial study by Facebook on the effects of a little tweaking, here and there, of what people saw in their news feed. They found that positive stories engendered a positive mood, and negative stories a negative mood. Setting aside the enormous ethical concerns involved in playing with the emotions of 700,000 people without their informed consent, it really does highlight how we are influenced by the people around us. "No man is an island", and all that.
Tip for the day (with slight gross-out warning): I hate wearing a respirator. The damn things never fit quite right, they fog up my glasses, they get full of condensed water from your breath and make your face itch. But when mulching I always wear one. The mulch I use is full of compost fines which float in the air and you really don't want that clogging up your lungs. You learn that quickly after blowing your nose in the shower following a job and having your snot come out black from being full of the stuff. Good to take the same precautions when handling potting mix and compost, too. You really, really don't want to contract Legionnaires Disease!