Aquatic Bacterial Community In Peatland Streams [Marcella Branagan]
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This document summarizes a study on the effects of drainage and restoration practices on aquatic bacterial communities and greenhouse gas concentrations in peatland streams. The study found seasonal differences in bacterial profiles across all stream orders. Bacterial community profiles also varied between catchment types (undrained, drained, restored). Specifically, drainage and restoration practices had a greater impact on bacterial communities than they did on carbon dioxide and methane concentrations. Future work is planned to analyze water chemistry and greenhouse gas data in more detail considering discharge variations, and to conduct additional analyses to identify causes of bacterial variability.
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Aquatic Bacterial Community In Peatland Streams [Marcella Branagan]
- 1. Aquatic bacterial community in peatland streams Kerry Dinsmore (CEH, Edinburgh), Angus Jackson (ERI), Mike Billet (CEH Edinburgh), Martina Maria Burtscher (ERI). Marcella Branagan Environmental Research Institute
- 2. Introduction Global carbon cycle. Streams conduits for movement of carbon. Drainage increases losses of dissolved organic carbon (DOC).
- 3. Knowledge gaps Are the aquatic bacteria affected by management practices. Is stream chemistry reacting in the same way as the bacterial community?
- 4. Hypothesis • Season will have an affect on the bacterial community profile. • The bacterial community profile will change according to management practices. • Dissolved CO2 and CH4 will be affected by management practices.
- 6. Catchment description - Drained
- 8. Methods Greenhouse gases, CO2 and CH4 Collected using head space method. Filter polymerase chain reaction (PCR) Water samples filtered using 0.2 µm filter paper. Millions of copies of a targeted 16S rDNA sequence.
- 9. Denaturing gradient gel electrophoresis (DGGE) 20 % 60 % OTU 1
- 10. Seasonal differences in aquatic bacteria across all stream orders ANOSIM P = 0.01 significant difference between seasons R value 0.331 non-metric MDS plot Winter Spring Bray - Curtis similarity Stress 0.09 Global R 0.337 P 0.01
- 11. Variability in aquatic bacteria between 1º and 2º streams non-metric MDS plot Winter Spring 1º D 2 º R 1 º R 2 º I 1 º I 2 º I 1 º R 2 º R 1 º D 2 º D 2 º D 1 º I Bray - Curtis similarity Stress 0.09 I - Un-drained D – Drained R – Restored
- 12. Differences in bacteria between catchments Bray - Curtis similarity Stress 0.18 Global R 0.331 P 0.001 Catchment P R Un-drained against restored 0.02 0.158 Un-drained against drained 0.001 0.339 Restored against drained 0.001 0.486 non-metric MDS plot Un-drained Drained Restored
- 13. Temporal differences in temperature,CO2 and CH4 concentrations between catchments Un-drained Drained Restored Non-metric MDS plot Catchment P R Un-drained against restored 0.001 0.482 Un-drained against drained 0.001 0.512 Restored against drained 0.847 0.048 Normalised Euclidean distance Stress 0.03 Global R 0.311 P 0.001
- 14. Conclusion • Seasonal differences can be seen in the bacterial profiles. • Less variability within catchment type in winter while spring showed higher variability. • The management practices seems to have more of an affect on the bacterial community when compared to CO2 and CH4 concentrations.
- 15. Future work Look at the DOC, DIC, and greenhouse gas data in detail considering the discharge. Run more DGGE gels looking at secondary streams and identifying possible causes of variability.
- 16. Acknowledgments Kerry Dinsmore for the analysis of water samples and gas samples at CEH. Mona Larson for filtering water samples. Jason McIlvenny for GPS data and maps. Everybody who has come sampling with me.
Editor's Notes
- Today I will be talking about the aquatic bacterial community found in peatland streams located in Scotland's flow country How these are affected by different management practices in the catchments And there relationship to greenhouse gas production 1st brief overview of why this is being studied 2nd present the hypothesis under investigation 3rd give a brief description of the catchments, their management practices and the sampling regime 4th introduce the methods that have been used. 5th talk about what we have found and discuss what this means. 6th talk about future work that will be conducted.
- Global Carbon cycle – store and sequester carbon northern peatlands count for only 3 % of the earths land area but have accumulated between 270 and 450 Pg of carbon. This represents 20 – 30% of the world’s estimated global C pool. In Scotland, peatlands cover 50% of the land area.
- Aquatic bacteria community are classed in this work as those that are present in the water column. The impact of disturbance on the aquatic bacteria community remains unknow In addition it is unknown the relationship between greenhouse gas production and bacteria community
- Investigating 3 catchments types un-drained, drained and restored catchment. Each catchment is composed of a small catchment nested within a large catchment. The intact catchment represents a catchment that is relatively pristine.
- The drained catchment has a network of drains that are believe to originate from 1950’s.
- The rehabilitated catchment was previously forested, with tree felled in early 2000 and drained also blocked using dykes Each of these catchments were sampled bimonthly between December 2008 until August 2010 Today I will be presenting monthly data taken from December 2008 till December 2009
- Filter paper cut into small pieces. Inserted into a PCR tube and mixed with primer that target a specific region of the 16S rDNA molecule.
- DGGE A denaturing gradient created by urea and formamide The PCR product is loaded, electrical current is applied and the gradient separates out the DNA sequences according to melting temperature Which creates a community profile. Each Novel band is given an identity depending on their position on the gel and a matrix of presences/absence data can be built from this
- To test for differences to the bacterial community as a consequence of season a non metric MDS analysis was done. Points that are closer together are similar while those that are far apart are dissimilar. Here we see that there are groups associated with season. An analysis of similarity was done to investigate if this was significant and found that there was significant differences between season. Temperature is important for bacteria, 2 oC differences between these two seasons
- We wanted to consider the variability in bacterial profiles between the primary and secondary streams within the catchment type Although there is little variability between primary and secondary in winter, in spring there was high variability esp. in the intact Need to investigate the 2nd streams as well.
- Here wanted to investigate the Hypo. Catchment type will have an effect on the bacterial community. Again we can see grouping Result Catchment found to be significantly different from one another. Intact and rehabilitated were significantly different while intact against drained and rehabilitated against drained were highly significantly different. Discussion Drained catchment