Subalpine gully‐head ribbon fens of the Lammerlaw and Lammermoor Ranges, Otago, New Zealand

Abstract

Vegetation patterns of subalpine gullyhead mires were investigated in the flat-topped Lammerlaw and Lammermoor Ranges, South Island, New Zealand. Two intensively studied mires each consist of a series of peaty terraces and scarps. Terraces may contain pools, elongated downslope in the narrow, lower altitude mire, but across slope in the broader, upper mire. A crest occurs on some terrace lips, and marginal "spillways" (channel-like zones) occur down some scarps. Some mires have drained by subsurface pipes.Vegetation analysis distinguished between grassland or herbfield on gully sides, vegetation of mire margins, showing aspect differences on the steeper, lower mire, and the vegetation of gully floors, including oligotrophic mire centre vegetation and species-poor pools. The crests, though warmer, bore no special vegetation type.Mineral soil beneath the peat indicates a previous non-mire vegetation, which has subsequently paludified. Scarp slumps indicate downslope creep of organic material. Peat fissures, and mineral, vegetation, and erosion dams all appear to have initiated development of some pools.Mires are designated gully-head ribbon fens. Patterning appears to be accentuated because of the mires' gully-head location on broad-topped ranges, and drainage of soligenous water from upslope gully sides. These apparently unique fens give insight into patterning in aapa mires, and merit special conservation.

Variable source and age of different forms of carbon released from natural peatland pipes

“…Soil pipes are significant subsurface structural features of peatlands and are known to occur in northern Europe, North America, Siberia, and the Southern Hemisphere [ Norrström and Jacks , 1996; Price , 1992; Rapson et al , 2006; Thorp and Glanville , 2003]. They have been widely recorded in UK blanket peats [e.g., Holden and Burt , 2002; Holden , 2005; Jones et al , 1997], where it has been shown that peat drainage, surface drying and Calluna vulgaris L.…”

The dynamics of natural pipe hydrological behaviour in blanket peat

“…Larger pipes have also been commonly reported in peatlands (e.g. Jones, ; Markov and Khoroshev, ; Woo and DiCenzo, ; Price, ; Norrstrom and Jacks, ; Jones et al ., ; Glaser, ; Gunn, ; Holden and Burt, ; Thorp and Glanville, ; Holden et al ., ; Holden, ; Rapson et al ., ). Soil conditions are generally too harsh for burrowing fauna in most peatlands, but peatlands may be conducive to piping because they are susceptible to rapid desiccation cracking.…”

IsEmpodisma minusthe ecosystem engineer of the FBT (fen–bog transition zone) in New Zealand?

“…Work by , 2004 has been pioneering in consistently addressing the FBT. Practical experimentation, such as that initiated in bogs by Clymo (1965) and Bellamy & Reiley (1967), and more recently demonstrated by Scheffer et al (2001), Heijmans et al (2002 and Adema et al (2006), offers much needed insight into bog mechanics.…”

“…A peat accumulating system or zone is a prerequisite, but it is otherwise far from clear how the process occurs (Hughes 2000;Hughes et al 2000Hughes et al , 2007Hughes & Dumayne-Peaty 2002;, 2004.…”

“…Indeed, spatial dispersion of successfully engineered FBTs might be the ultimate cause of the string or flark patterning in mires which has generated so much discussion in the literature (e.g. Moore 1982Moore , 1991Glaser & Janssens 1986;Foster & Fritz 1987;Rapson et al 2006;Eppinga et al 2008).…”