Sphagnum mosses – Ecosystem engineers of bogs

I evaluated production and decomposition characteristics of six dominant Sphagnum species in their natural microhabitats distributed along the gradient of water table in an open ombrotrophic bog. The growth in length was much higher in pools and hollows than in hummocks but the resulting annual production was roughly similar between the microhabitats due to a greater shoot and bulk density in hummocks. Although hummocks provided much higher potential for decomposition than hollows, the Sphagnum litter decomposed more slowly in hummocks due to much lower litter quality of the hummock sphagna. Thus the hummock Sphagnum species possess both principal mechanisms participating in maintaining hummocks above hollows – a sufficient production rate and limited decomposition rate. These mechanisms emphasize the role of Sphagnum mosses as autogenic ecosystem engineers controlling also the microhabitat diversification in patterned mires