Forest and Water POMS Study

• Forest now constitutes 10% of land cover in Ireland (from 1% in 1920)– 43% is on peat soils– Objective to expand forest cover to 17% in the next 30 years

• Forest cover has beneficial effects (e.g. biodiversity) but can lead to increased pressure on waters if it is not managed correctly

• Identified as significant pressure on waters in Ireland in the WFD Characterisation and Water Matters reports

• Forest and Water POMS Study aims:– To assess the potential impact of afforestation and forest operations on

water status in river and lake water bodies – To develop an updated risk assessment methodology– To develop a Programme of Measures to achieve WFD compliance

• Acidification, Eutrophication, Sedimentation• Dangerous Substances

Forestry Study - Background and Aims

Forestry Study – Risk Assessment

• Updated Risk Assessment (Pressure-Pathway-Receptor Model)

• Pressure layer

– 2007 update of the 1998 Forest Inventory and Planning System (FIPS) layer

• Pathway layer

– geology, soils and subsoils maps

• Receptor sensitivity layer

– hydro-geology, chemistry, status, protected species and habitats

• Highlight areas of potential risk to waters from forestry activities

• Will be available to Local Authorities

Forestry Study – Special Studies• Acidification Study (UCD)

– Fieldwork, acidification impact map

– Risk of acidification is associated with waters under closed-canopy conifer forests on base-poor

rocks and soils (e.g. peat soil areas)

– Acidification effects were observed when forest cover exceeded certain %ages, depending on the

hydro-geological setting

• Sedimentation/Eutrophication Study (UCC)

– Fieldwork, sedimentation/eutrophication impact map

– Impacts more limited in extent and generally associated with activities (such as forest roading,

harvesting and replanting) rather than forest extent

– However, high forest cover on peat soils may potentially lead to impacts on waters

• Dangerous Substances Study (WRBD)

– Register and map of dangerous substances usage related to forestry (herbicides and pesticides)

• Research indicated that problems were generally associated with older forestry

planted prior to the introduction of Forest Service Guidelines in 1990

Basic Measures

• Forestry Act, 1946– main control– grant support system administered by the Forest Service– requires adherence to Forest Service guidance documents and codes of practice

• New Forestry Bill (currently being drafted) – will replace the 1946 Forestry Act– will strengthen sustainable forestry management

• Aerial Fertilisation Regulations– control diffuse pollution from this source

• New Freshwater Pearl Mussel Guidelines – Forest Service– Protect this species from forestry activities

• Existing Guidelines and Codes of Practice – Forest Service– Suite of documents relating to various aspects of forestry activity

Supplementary Measures

• Suite of supplementary measures has been developed– Have been tested for technical feasibility

– Some require further research as to their effectiveness in the Irish situation

• Envisaged that a combination of supplementary measures will be used in any one location

• WRBD POMS Study have assigned appropriate supplementary measures on a site by site basis

• LAs will choose which supplementary measure to apply using the information supplied to them in GIS and spreadsheet format

• FM - Management Instruments– updating and cross-referencing regulations, guidance, and maps – education and awareness campaigns

• FA - Acidification Measures • FE - Eutrophication and FS - Sedimentation Measures

– forestry management measures to limit the potential impacts of forestry operations

• FP - Pesticide use measures – controls on insecticide and herbicide useage

• FH - Hydromorphological measures– mainly recommendations for further research

Supplementary Measures

Supplementary MeasuresReduce Pressures and Impacts

FM Ensure regulations and guidance are cross referenced and revised to incorporate proposed measures.

FA Avoid or limit (to below critical thresholds) afforestation on 1st and 2nd order stream catchments in acid sensitive catchments

FA Restructure existing forests to include open space and structural diversity through age classes and species mix, including broadleaves

FA Revise the Acidification Protocol to ensure actual minimum alkalinities are detected (that is ensure sampling under high flow conditions) and revise boundary conditions for afforestation in acid sensitive areas.

FE & FS Avoid or limit forest cover on peat sites

FE & FS Change the tree species mix (for example broadleaves) on replanting

FE & FS Limiting felling coup size

FE & FS Establish new forest structures on older plantation sites (including riparian zones, drainage layouts, species mix, open areas)

FH Audit existing drainage networks in forest catchments

FP Reduce pesticide usage

FP Pre-dip trees in nurseries prior to planting out

FP Maintain registers of pesticide use

Supplementary Measures

Remediate Pressures and Impacts

FA Mitigate acid impacts symptomatically using basic material (e.g. limestone or sand liming)

FA Manage catchment drainage to increase residence times and soil wetting, including no drainage installation in some areas

FA Implement measures to increase stream production – for example with native woodland in riparian zones.

FE & FS Establish riparian zone management prior to clearfelling

FE & FS Enhance sediment control

FE & FS Manage catchment drainage to increase residence times and soil wetting, including no drainage in some locations

FH Enhance drainage network management – minimise drainage in peat soils

FP Develop biological control methods

Further Research Recommendations

• Elucidation of the dominant acidification mechanism in Ireland• Application of native riparian woodland scheme to conifer forest on peat

soils. Evaluate contribution of riparian woodland to stream productivity and degree of compensation achieved.

• Research into the hydromorphological impacts• Evaluation of liming options for Irish catchments, including pre-liming,

broadcast liming aerial application, silo based, grinding mills, base hardcore material for roading.

• Trialling out identified methodologies in some target catchments.• Catchment scale trialling of native riparian woodlands in enhancing stream

productivity and offsetting potential impact of forest on acid sensitive areas.• Research into buffer zones • Trialing different methods for timber/brash extraction• Research into drainage control• Test the effectiveness of conifers/other trees versus natural regeneration. • Evaluate application and effectiveness of Decision Support System in

development by Coillte for the Western Peatlands forested areas.