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Forests and surface water Forests and surface water eutrophication and sedimentation eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Michael Bruen, Dr Ted Farrell, Dr Farrell, Dr Jan-Robert Jan-Robert Baars, Dr Robert Baars, Dr Robert Cruikshanks, Dr Ronan Cruikshanks, Dr Ronan Matson, Mr James Johnson Matson, Mr James Johnson Dr Simon Harrison, Dr Dr Simon Harrison, Dr Stephen Hutton, Prof. Stephen Hutton, Prof. John O’Halloran, Dr John O’Halloran, Dr Guillaume Juhel, Mr Paul Guillaume Juhel, Mr Paul Phelan Mr Tad Kirakowski Phelan Mr Tad Kirakowski University College Cork University College Cork University College Dublin University College Dublin
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Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Dec 16, 2015

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Page 1: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Forests and surface water eutrophication and Forests and surface water eutrophication and sedimentationsedimentation

Dr Mary Kelly-Quinn, Dr Michael Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Bruen, Dr Ted Farrell, Dr Jan-Jan-Robert Baars, Dr Robert Robert Baars, Dr Robert Cruikshanks, Dr Ronan Matson, Mr Cruikshanks, Dr Ronan Matson, Mr James Johnson James Johnson

Dr Simon Harrison, Dr Stephen Dr Simon Harrison, Dr Stephen Hutton, Prof. John O’Halloran, Dr Hutton, Prof. John O’Halloran, Dr Guillaume Juhel, Mr Paul Phelan Mr Guillaume Juhel, Mr Paul Phelan Mr Tad KirakowskiTad Kirakowski

University College Cork University College Cork University College DublinUniversity College Dublin

Page 2: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

IntroductionIntroductionConifer afforestation of catchments is known to pose a risk to the chemical and biological integrity of receiving waters:

- Low pH (mid and mature phase)

- High sediment loading (planting and harvesting)

- High concentrations of plant nutrients and other dissolved and particulate substances (planting and harvesting)

- Low light and temperature (mature phase)

Although all these effects have been documented at local scales, there has been few attempts to assess the wider scale risk of commercial conifer afforestation to stream water quality.

Page 3: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

The impact of a particular plantation will depend on many factors including:

- Geology, geomorphology and soil type.

- Small scale ‘random’ factors such as the nature of a particular planting or felling operation, rainfall patterns, water drainage from a site.

Page 4: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Research question:Research question:What is the risk posed by afforestation to receiving waters?

- Assess the relative impact of forestry on water quality, in relation to other land uses.

- Effective mitigation measures for current and future plantations

Page 5: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Sampling

200+ streams draining upland catchments across the Republic were sampled three times in 2007-8:

• Sampling was restricted to 1st & 2nd order upland streams

•‘Forest’ sites were streams that flowed through conifer plantations

•‘Control’ sites were streams that flowed through neighbouring unforested moorland

• Forested catchments were either mature plantations without felling or mature plantations with felling

• Catchments were chosen in peat and podsol/lithosol (poorly drained mineral soil) catchments

Page 6: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Chemical parameters: Water samples taken 3x from each stream. Comprehensive range of parameters analysed, including plant nutrients, heavy metals, DOC, suspended solids, pH, alkalinity. Sediments Sediment collected using a modified Surber sampler. Sample sieved at two fractions; coarse (250-1000μm) and fine (50-250μm), dried and weighed.

Macroinvertebrates: 3 multi-habitat kick samples taken from each stream on one occasion.

Diatoms: Diatoms scraped from stone surfaces taken from each stream in summer.

Page 7: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Sampling Locations

101 Peat catchment streams

88 Podsolic lithosolic streams

Page 8: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Results – water chemistry

Page 9: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Mean water chemistry parameters (1)

Peat catchments Podsol lithosol catchments

Page 10: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Peat catchments Podsol lithosol catchments

Mean water chemistry parameters (2)

Page 11: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Mean DOC concentration in streams vs percentage catchment felled within last 5 years

% catchment felled

Page 12: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Mean total ammonia concentration in streams vs percentage catchment felled within last 5 years

% catchment felled

Page 13: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Mean total phosphorus in streams vs percentage catchment felled within last 5 years

% catchment felled

Page 14: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Draft European Communities Environmental Objectives (Surface Waters) Regulations 2008: these define ‘high’ and ‘good’ water quality status according to a suite of chemical and biological parameters:

Mean MRP (mg P/l)High status = ≤ 0.025 mg P/LGood status = ≥ 0.025 ≤ 0.035 mg P/lFailed status = >0.035 mg P/l

Mean Ammonia (mg N/L)High status = ≤ 0.040 mg N/LGood status = ≥ 0.065 ≤ 0.040 mg N/lFailed status = > 0.065 mg P/l

Criteria for impact assessment:

Page 15: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Phosphorus water quality status of streams in data set

Impact assessment Phosphorus (SRP)

Peat catchments Podsol lithosol catchments

Control Mature Clearfelling Control Mature Clearfelling

>0.035 mgP/l Failed status 0.0 0.0 14.0 0.0 0.0 0.0

0.025-0.035 mgP/l Good status 0.0 0.0 9.3 0.0 0.0 0.0

<0.025 mgP/l High status 100.0 100.0 76.7 100.0 100.0 100.0

SRP concentration Status

Page 16: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Total Ammonia water quality status of streams for the different catchment soil types

Impact assessment Total Ammonia

Peat catchments Podsol lithosol catchments

Control Mature Clearfelling Control Mature Clearfelling

>0.065 mgN/l Failed status 0.0 4.0 18.6 0.0 0.0 2.6

0.04-0.065 mgN/l Good status 3.0 20.0 32.6 3.2 16.7 5.1

<0.04 mgN/l High status 97.0 76.0 48.8 96.8 83.3 92.3

Total Ammonia concentration

Status

Page 17: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Results - Macroinvertebrates

Page 18: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Small Stream Risk Scores

Peat catchments

Podsol lithosol catchments

Page 19: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Invertebrate metrics

Peat catchments Podsol lithosol catchments

Page 20: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Trophic Diatom IndexTD

I

Page 21: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

Conclusions

Clear impacts of forestry operations on stream water chemistry and sediment bedload.

Elevated levels of key eutrophication and sedimentation parameters seen in streams draining peat catchments, but not mineral-soil podsol lithosol catchments.

High percentage of streams draining peat catchments subject to clearfelling fail water chemistry standards.

Benthic macroinvertebrate and diatom metrics reflect reduced water quality in streams draining forests planted in peatsoil catchments.

Page 22: Forests and surface water eutrophication and sedimentation Dr Mary Kelly-Quinn, Dr Michael Bruen, Dr Ted Farrell, Dr Jan- Robert Baars, Dr Robert Cruikshanks,

..Don’t plant or re-plant conifer trees on peat!