Effects of tephra deposition on mire vegetation: a field experiment in Hokkaido, Japan

Abstract

Summary 1The influence of tephra (aerially transported volcanic ejecta) on mire vegetation was investigated in a field experiment at Sarobetsu Mire, northern Hokkaido, Japan, which simulated relatively thin, widespread tephras. It was carried out in the centre of a raised part of the mire in a Carex middendorffii -Sphagnum papillosum community. 2 We tested the effects of varying tephra layer thickness, grain size and season of the simulated tephra impact. 3 Vegetation surveys and analyses of the mire pore water were carried out before and 1 and 2 years after tephra application. Redox potential, oxygen saturation and sulphide concentration were measured in the surface layer of selected plots after 10 months. 4 Pore water chemistry and oxygen saturation changed significantly in some treatments. Some plant species disappeared from certain treatments after tephra application, but the majority survived. Colonization by non-mire species played a significant role in only one treatment. Mosses were more strongly affected by the disturbance than vascular plants. 5 Tephra had stronger effects on the vegetation when layers were thicker, were more fine-grained and when applied at the beginning rather than at the end of the growing season. 6 Moderate tephra deposition is unlikely to cause long-term changes in mire development. Subsequent succession depends on properties of the tephra, on the vegetation type (e.g. life-forms) and on the season, but the original vegetation will probably recover even where the moss layer is severely damaged, as Sphagnum spp. can re-establish by growing through tephra at least up to 6 cm thick.

Vegetation structure influences the retention of airfall tephra in a sub-Arctic landscape

“…Racomitrium lanuginosum can absorb falls of up to 8cm without incurring significant 108 damage; Zobel & Antos (1997) noted moss recovery from falls < 2cm in forest adjacent 109 to Mount St. Helens and Hotes et al (2004) reported the recovery of Sphagnum spp. 110 moss from beneath deposits 6cm thick.…”

A chronosequence approach for detecting revegetation patterns after Sphagnum‐peat mining, northern Japan

“…During the terrestrialization, peat, mostly consisting of Sphagnum spp., accumulated, and the peat depth now reaches ca. 6 m (Hotes et al 2004). Two major vegetation types that must have been major components of the original vegetation are the Carex middendorffii-Sphagnum papillosum community and the Carex middendorffii-Sphagnum magellanicum community (Tachibana and Ito 1980).…”

Persistent effects of a tephra eruption (AD 1655) on treeline composition and structure, Mt Taranaki, New Zealand

“…Tephra deposits are generally deepest in close proximity to the volcanic vent, and become progressively thinner with increasing distance from the source (Carey 2005). The effect of tephra on vegetation is primarily related to the depth (thickness) of the ejected material (Eggler 1963;Vucetich & Pullar 1963;Hotes et al 2004;Antos & Zobel 2005;Tsuyuzaki & Hase 2005;Gomez-Romero et al 2006).…”