Quote:
Originally Posted by SouthPark
Under what conditions? Live sphagnum apparently has neutral pH.
Maybe you're thinking of stage 2 ------ peat moss.
|
Under all conditions, unless there's too much calcium carbonate and it neutralises the acids.
Here's what I've been told by a biologist specialised in Sphagnum:
"Both living and dead Sphagnum lowers the pH of their surrounding water every time to a value around pH 3 to 4. This is a strong buffered system and if you would add distilled water of pH around 7, it will immediately become pH 3 or 4 once it is around the Sphagnum.
If you want a short technical explanation for this, they do it by exchanging kations for protons on the polyuronic acids in the cell wall.
The benefit of this acidifying mechanism is double. Bacteria and fungi growth rates are much lower so they don't manage to decompose the dead Sphagnum, allowing it to build up a peat layer. This keeps acting as a sponge, keeping water for optimal Sphagnum growth. The high water table also slows down Sphagnum decomposition because conditions are anoxic in water.
The wet, acidic anoxic conditions in bogs are the reason that vascular plants grow extremely poorly in bogs to the point where Sphagnum remains the most dominant plant. It's a climax vegetation type and the Sphagnum is also the 'ecosystem engineer' of this system. Another reason for this mechanism is that the kation capture allows Sphagnum to monopolyze the few present nutrients in the peat, stealing them away from possible competitors."
I've tried to replicate this by soaking live S. centrale in rainwater, but testing low pH with Phenol red isn't a good idea. I'll have to grab pH strips.
Some species, like Sphagnum angustifolium, like a more basic water and won't be so acidic.
Quote:
Originally Posted by vegetalmatter
I have however noticed that a select few heads are developing brown and black tips, possibly from fertilizer or tips drying out faster
|
It does look nice! Tannin accumulation is also an issue, if you can spray it daily or so it will help a lot.
Hybrid Mode
