Growth potential of three Sphagnum species in relation to water table level and peat properties with implications for their restoration in cut-over bogs
Published source details
Grosvernier P., Matthey Y. & Buttler A. (1997) Growth potential of three Sphagnum species in relation to water table level and peat properties with implications for their restoration in cut-over bogs. Journal of Applied Ecology, 34, 471-483.
Published source details Grosvernier P., Matthey Y. & Buttler A. (1997) Growth potential of three Sphagnum species in relation to water table level and peat properties with implications for their restoration in cut-over bogs. Journal of Applied Ecology, 34, 471-483.
In order to assess the potential of revegetation of cut-over peat bogs in bogs of the Swiss Jura, a glass house experiment was conducted. Growth in length and weight of three species of Sphagnum moss (S.fuscum, S.magellanicum and S.fallax) on five different peat types and two water levels was studied.
Sphagnum species: Three species of Sphagnum moss commonly found in the Swiss Jura bogs, and also abundant else where in the northern hemisphere were grown in a glasshouse experiment: S.fuscum, S.magellanicum and S.fallax. Circular mats 13.3 diameter x 5 cm thick of sphagnum were collected in the field for the purpose of the glass house experiment conducted at Neuchâtel.
Peat and water table: The Sphagnum mosses were cultivated in PVC pots at natural density on cores of five different peat types, representing a gradient of increasing disturbance. Two water levels (-1 cm and –40cm) were controlled and maintained to simulate natural and drained situations. There were three replicates of each treatment (90 pots in total).
Greenhouse climate: Shading was provided at about 80% to ensure the glasshouse did not overheat whilst maintaining suitable incident light for growth. Rainwater was used to maintain moisture as required (300 mL water sprayed on each pot).
Growth: Ten Sphagnum plants, cut to 5 cm in length and marked with a polyester thread, were measured for growth rate and dry weight.
Sphagnum growth was most influenced by the water level, rather than peat type. S.fallax in particular was strongly dependent on water level. At high water level its growth in length was much greater than the other two species. Also despite its slender form, mass increments were similar to those of S.magellanicum.
S.fallx clearly had the highest growth at high water levels, reflecting the field conditions that it has been observed growing best. Yet, in the Swiss Jura Mountains, it is the most widespread species in paludification processes of drained bogs (i.e. bog expansion resulting from the gradual rising of the water table as accumulation of peat impedes water drainage) after the cessation of peat mining or harvesting. The reasons for this include its good resistance to desiccation and recovery ability, greater efficiency of photosynthesis at low humidity, fast growth rate (as observed in this experiment), and its capacity to grow horizontally.
Peat type was influential only when the water table was at a low level (-40 cm), simulating drained conditions. Results of analyses taking into account peat physical and chemical properties show that drained sites undergo a strong chemical disturbance, which affects Sphagnum growth. However, depending on the evolution of the peat, a particular combination of chemical and physical properties may actually favour Sphagnum growth even at a low water table.
Conclusions: Results from this glasshouse experiment, suggest that S.fallax should be favoured above S.fuscum and S.magellanicum as a pioneer in bog restoration to stimulate rapid colonization and recovery of Sphagnum on which other species characteristic of ombrotrophic bogs can re-establish.
Note: If using or referring to this published study, please read and quote the original paper, this can be viewed at: http://links.jstor.org/sici?sici=0021-8901%28199704%2934%3A2%3C471%3AGPOTSS%3E2.0.CO%3B2-9