『Abstract
Since the 1950s, large areas of upland peat have been afforested
in northern European countries. Due to the poor phosphorus (P)
adsorption capacity and low hydraulic permeability in blanket
peat soil and increased labile P sources, harvesting these blanket
peat forests can significantly increase P concentrations in the
receiving aquatic systems. This paper briefly reviews the current
management practices on the control of P releases from forestry
in Ireland and the UK, and proposes a possible novel practice
- grass seeding clearfelled areas immediately after harvesting,
which should reduce P release from blanket peat forest harvesting.
The study was conducted in the Burrishoole Catchment in the west
of Ireland. A field trial was carried out to identify the successful
native grass species that could grow quickly in the blanket peat
forest. The two successful grass species - Holcus lanatus
and Agrostis capillaris - were sown in three blanket peat
forest study plots with areas of 100, 360, and 660 m2
immediately after harvesting. Areas without grass seeding were
used as controls. One year later, the P content in the aboveground
vegetation biomass of the three study plots were 2.83, 0.65, and
3.07 kg P ha-1, respectively, which were significantly
higher than the value of 0.02 kg P ha-1 in the control
areas. The water extractable phosphorus in the three study plots
were 8.44, 9.83, and 6.04 mg (kg dry soil)-1, respectively,
which were lower than the value of 25.72 mg (kg dry soil)-1
in the control sites. The results indicate that grass seeding
of the peatland immediately after harvesting can quickly immobilize
significant amounts of P and warrants additional research as a
new Best Management Practice following harvesting in the blanket
peatland forest to mitigate P release.
Keywords: P release; Blanket peat; Forest harvesting; Grass seeding;
Holcus lanatus; Agrostis capillaris』
1. Introduction
1.1. Current mitigation methods
1.2. A possible novel practice - grass seeding
2. Materials and methods
2.1. Site description
2.2. Trial and plot-scale experiment
2.3. Aboveground vegetation biomass and P content measurement
2.4. Soil water extractable phosphorus measurement
2.5. Data analysis
3. Results
3.1. Biomass and P content of natural re-vegetation in blanket
peat forests after harvesting
3.2. Successful germination grass species
3.3. Impact of grass seeding on the biomass and P content of
aboveground vegetation
3.4. Impact of grass seeding on soil water extractable phosphorus
4. Discussion
5. Future research
6. Conclusion
Acknowledgments
References