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Long-term integrated research at ultrabasic catchment (Pluhův Bor, Czech Republic)

Pavel Krám1, Jakub Hruška1, Anna Lamačová1, Oldřich Myška1, Jan Čuřík1, František Veselovský1, Juraj Farkaš1, Martin Novák1, Tomáš Navrátil2, Jan Rohovec2
1 Czech Geological Survey
2 Institute of Geology AS CR, v.v.i.

O 1.11 in Long term trends in the functioning of ecosystems

15.07.2014, 11:00-11:20, H18

The 21.6-ha Pluhův Bor catchment is almost entirely forested by mature stands of Norway spruce (Picea abies). It is underlain mainly by ultrabasic rocks (serpentinite; tremolite and actinolite schists; 79% of outcrops) and partially by basic rocks (e.g. amphibolite; 13% of outcrops) (Krám et al. 2009). The catchment was investigated in 1991-2014. Water monitoring consisted of measurements of bulk precipitation, throughfall, soil water (five depths 10-90 cm), ground water (26 m) and stream water. Up to 35 chemical compounds and six isotopes (including Ca and Mg) were analyzed in water. Rocks were sampled at thirty outcrops, soils at six locations and trees at five locations. Long-term mean annual precipitation and throughfall were 800 and 541 mm/yr, respectively, and mean stream water runoff was 285 mm/yr (1992-2013 water years). Productivity of slow-growing forest was co-limited maily by low supply of K and P (Rosenstock et al. 2014). Slow growth appears to be caused also by Mg oversupply and Ni and Cr toxicity. Atmospheric deposition and chemical weathering generated near-neutral magnesium-bicarbonate-sulfate stream water. Stream water exhibited extremely rapid decrease of sulfate in the 1990s. Dissolved organic C in drainage water increased significantly (Hruška et al. 2009), the mean annual increase was 0.4 mg/L/yr in stream water between 1993 and 2013. Stream water was partially acidified only during short-term hydrologic episodes when the runoff was dominated by flow through surface soil horizons. A typical feature of stream water during high flow episodes is elevated concentration of several metals (Ni, Cr, Hg). Benthic macroinvertebrate richness was intermediate in the main stream with 55 identified taxa (Horecký et al. 2013). Impacts of anticipated global climate change on water budget for 2071-2100 were evaluated by the Brook90 model (Benčoková et al. 2011). Runoff in summer is expected to decrease noticeably and the stream might regularly dry up. The MAGIC model was used to simulate corresponding future soil and water chemistry, depletion of soil exchangeable pools of K is a major threat.

References:

Benčoková et al. (2011) Future climate and flow patterns changes in Czech headwater catchments. Climate Research, 49, 1-15.

Horecký J. et al. (2013) Benthic macroinvertebrates of headwater streams with extreme hydrochemistry. Biologia, 68, 303-313.

Hruška J. et al. (2009) Increased dissolved organic carbon (DOC) in Central European streams is driven by reductions in ionic strength rather than climate change or decreasing acidity. Envir. Science and Technol., 43, 4320-4326.

Krám P. et al. (2009) Geoecology of a forest watershed underlain by serpentine in central Europe. Northeastern Naturalist 16, Spec. 5, 309-328.

Rosenstock N. et al. (2014) Rock-eating fungi are picky eaters. Geoph. Res. Abs. 16, EGU2014-11891.

Acknowledgement: Support of the European Commission (SoilTrEC, GA 244118) and the Czech Science Foundation (P210/11/1369) is appreciated.

 



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last modified 2014-04-04