FORESTSOILC

Soil carbon stock changes and greenhouse gas fluxes in Irish forests

DOWNLOAD 2009 REPORT AS PDF (pdf 353Kb)  
DOWNLOAD 2009 REPORT IN IRISH (pdf 329Kb) 

PROJECT TEAM
Prof. Gerard Kiely, University College Cork*
Michael Wellock, University College Cork
Christina LaPerle, University College Cork
Nelius Foley, University College Cork
Dr Kevin Black, FERS Ltd

* Email: g.kiely@ucc.ie

COMPLETION DATE:
May 2011

BACKGROUND
Forests are a central component of the global (C) cycle and are estimated to store 77% of the C stored in vegetation and 39% of the C stored in soil. Therefore, the Kyoto Protocol includes mechanisms such as Article 3.3 for parties to use C sequestration in forests to meet emission reduction targets. Article 3.3 allows changes in C stocks due to afforestation, reforestation, and deforestation since 1990 to be used to offset emissions. Due to the rapid rate of afforestation in Ireland since 1990 Article 3.3 offers great potential for Ireland to offset emissions from other sources. In order to meet international reporting obligations Ireland must collect nationally specific data to increase the accuracy and reduce the uncertainty of the estimation of the GHG emissions offset by afforestation.

OBJECTIVES

  • To use the paired plot approach to investigate the affect of afforestation on soil C stocks at 30 forest sites and to estimate forest soil carbon stocks.
  • To determine the effect of afforestation and deforestation on CO2 and CH4 dynamics in peat soils and to develop CO2 and CH_ emission factors for afforested and deforested blanket peat.
  • To determine the effect of broadleaf afforestation of mineral soils on soil C stocks.
  • To investigate the effect of afforestation on CO2 and N2O fluxes.

    PROGRESS
    National scale soil C stocks: The aim is to develop a quantitative assessment of the carbon (C) stocks in Irish forest soils. Following the development of sampling and laboratory protocols and some preliminary field work, 21 mineral soil sites (i.e. 21 pairs to include one forest site plus a nearby non forest site), 8 peaty mineral soil sites and 10 peat soil sites are to be sampled. The paired concept grew out of work in New Zealand.
    The mineral soil sites have been divided into eight sampling groups based on soil type (brown earths, podzols, brown podzolics, and gleys) and forest type (coniferous, mixed, or broadleaf). The mineral soil forest sites are paired with a site representative of pre-afforestation site conditions.
    The peat and peaty mineral (peaty gley and peaty podzol) sites are not be paired due to the level of variability in peat depth within a site.
    It is important to note that UCD will be sampling the same number of sites in the northern half of the country. All UCC sites have been sampled to date. Average carbon density for three conifer gley sites changes with depth. As expected the carbon density decreases as the depth increases. Also, the total carbon density (including the litter layer) is greater in the forest compared with its paired pre-afforestation site. The average bulk density for five low level (elevation < 150 m) blanket peat sites changes with depth. According to these data, the bulk density does not appear to increase as depth increases. This finding is contrary to some of the literature which predicts that the bulk density would increase down the profile.
    C dynamics in organic soils: Gas sampling for CO2 and CH4 began in July 2009. Litter collectors have been put out at all sites. Litter bags will be put out at sites and soil will be sampled for fine root turnover in January 2010.
    C stocks and stock changes in mineral soils: Site selection is in progress.
    CO2 and N20 fluxes in recently afforested grassland: The aim of this WP is to assess the impact of afforesting grassland on the fluxes of CO2. N2O and CH4 from the soil. The site selected is a recently (2005) afforested ~ 10 ha grassland site at Dripsey, Co Cork. The eddy covariance flux tower was installed in the summer of 2008. The instrumentation on the 2 m scaffold tower includes: radiation and PAR sensors; air temperature and humidity sensors; a LICOR 7500 sensor for 10 Hz CO2 and H2O concentrations; a 3D sonic anemometer; soil temperature and soil moisture.
    Data collection began in September 2008. The data collected includes meteorological and flux data. For the measurement of N2O and CH4 fluxes from the Dripsey afforested site, 16 permanent collars have been placed at the soil surface in two transects. Soil moisture and temperature probes have been installed under each collar to allow for continuous measurements. The N2O fluxes will be measured monthly during the winter and weekly during the growing season, measurements began December 2009.

    ACTIVITIES PLANNED
  • National scale soil C stocks: Complete the estimate of soil carbons stocks and stock changes in Irish forest soils.
  • C dynamics in organic soils: Continue gas sampling for CH4 and CO2 fluxes and to collect litter decomposition and quantity data as well as root turnover data.
  • C stock changes in mineral soils: Select sites and to complete site sampling.
  • CO2 and N2O fluxes in recently afforested grassland: Continue N2O data collection.

     

    OUTPUTS
    A national workshop with COFORD and UCD is planned for February 2010.


    2008 report

    PROJECT TEAM
    Prof. Gerard Kiely, University College Cork*
    Michael Wellock, University College Cork
    Christina LaPerle, University College Cork
    Nelius Foley, University College Cork
    Dr Kevin Black, FERS Ltd.

    * Email: g.kiely@ucc.ie

    COMPLETION DATE: May 2011

    BACKGROUND
    The Kyoto Protocol includes mechanisms such as Article 3.3 for parties to use C sequestration in forests to meet emission targets. Article 3.3 allows changes in C stocks due to afforestation, reforestation, and deforestation since 1990 to be used to offset emissions. Due to the rapid rate of afforestation in Ireland since 1990 Article 3.3 offers a great potential for Ireland to offset emissions from other sources. In order to meet international reporting obligations, Ireland must collect nationally specific data to increase the accuracy and reduce the uncertainty of the estimation of the greenhouse gas emissions offset by afforestation.

    OBJECTIVES
  • To investigate the effect of afforestation on soil C stocks at 40 forest sites and to estimate forest soil carbon stocks.
  • To determine the effect of afforestation and deforestation on CO2 and CH4 dynamics in peat soils and to develop emission factors for afforested and deforested blanket peat.
  • To determine the effect of broadleaf afforestation of mineral soils on soil C stocks.
  • To investigate the effect of afforestation of grassland on CO2 and N2O fluxes.

    PROGRESS
    Work on developing a quantitative assessment of the carbon (C) stocks in Irish forest soils commenced in July 2007. Following the development of sampling and laboratory protocols and some preliminary field work, it was agreed that 21 mineral soil sites (i.e. 21 pairs to include one forest site plus a nearby non-forest site), 8 peaty mineral soil sites and 10 peat soil sites are to be sampled. The paired concept grew out of review work in New Zealand.
    The mineral soil sites have been divided into eight sampling groups based on soil type (brown earths, podzols, brown podzolics, and gleys) and forest type (coniferous, mixed, or broadleaf). The mineral soil forest sites are paired with a site representative of pre-afforestation site conditions.
    The peat and peaty mineral (peaty gley and peaty podzol) sites will not be paired due to the level of variability in peat depth within a site.
    Nineteen of the 21 mineral paired sites, two of the 8 peaty mineral sites and none of the peat sites have been field sampled to date. It is planned to complete the mineral site sampling by the end of February 2009 and the peat sites by May 2009. The laboratory analysis of soils is ongoing.
    With regard to the aim to assess the impact of afforesting grassland on the fluxes of CO2, N2O and CH4 from the soil, the selected site was recently afforested (2005) ~10 ha grassland site at Dripsey, Co Cork. The eddy covariance flux tower was installed in the summer of 2008. The instrumentation on the 2 m scaffold tower includes: radiation and PAR sensors; air temperature and humidity sensors; a LICOR 7500 sensor for 10Hz CO2 and H2O concentrations; a 3D sonic anemometer; soil temperature and moisture. Data collection on the flux tower began in September 2008, and included meteorological and flux data.
    At the same site, sixteen permanent collars (along with soil moisture and temperature probes) have been placed at the soil surface in 2 transects to measure the N2O and CH4 fluxes. The N2O fluxes will be measured monthly during the winter and weekly during the growing season.

    ACTIVITIES PLANNED
    National scale soil C stocks: All field and laboratory work should be complete by July 2009, and estimation of SOC stocks will begin.
    C dynamics in organic soils: Begin work on project in February 2009 and have initial results for July 2009.
    C stock changes in mineral soils: Begin work on this after completion of work on national scale soil C stocks.
    CO2 and N2O fluxes in recently afforested grassland: Begin N2O data collection after the installation of the soil temperature and moisture probes.