Project results

A network of 14 small headwater catchments was established in 1994 for studying the effects of acidification, eutrophication and global impact of climate change. Small catchments ranging from tenth to several hundred hectares in size represent an ideal research sites for evaluating of hydrological and hydrochemical balances. Unified methodology - continuous flow measurements in the closure profile, a monthly chemical analysis of precipitation, throughfall and runoff – are used to calculate the flow of ecologically important ingredients (nitrogen, phosphorus, carbon, aluminum, base cations, etc.). Currently we have 20 years of continuous monitoring of mass balances of ecologically important elements in a monthly/weekly time resolution.

Current research has revealed rapidly changing chemical composition of precipitation and surface water in the Czech Republic. Primarily in response to the reduced input of acidifying agents (reduction of sulfur deposition). Changing of surface water cheistry has a major impact on biodiversity of invertebrates in headwater areas. Thus, changing of chemical composition of surface water has an impact on the ecological function of flows and significantly affects the resistance of aquatic ecosystems to pressures from the altered hydrological situation caused by global climate change.

A major impact of the composition of surface water on diversity of macrozoobentos was previously demonstrated in selected watersheds from the GEOMON network. The uniqueness of long-term data of chemical composition of individual components in the catchment area is obvious in the context of a close relationship between the chemical composition of water and the diversity of individual plant and animal species. Modeled estimates of the chemical composition of surface waters may be used to estimate the changes in the diversity of flora and fauna inhabiting these headwater areas. If these estimates are made on organisms with high potential indicator showing the quality of the habitat, eg. species composition of benthic algae, may thus obtained dependences and projections used to estimate not only future chemical but also the ecological status of the territory.

Atmospheric deposition

Long-term monitoring of flows of ecologically important elements in precipitation and surface waters takes place in 14 small forest catchment of GEOMON net. Samples are collected throughout the duration of the project in monthly intervals.

In samples are measured following parameters: Na, Ca, K, Mg, SO4, NO3, NH4, Cl, F, Mn, Fe, Zn, Al, As, Cd, Pb, Ni, DOC (Dissolved Organic Carbon) and DON (dissolved organic nitrogen), followed by pH and conductivity. The outcome is a database of substance flows for the reporting period presented in monthly intervals.

Stream chemistry

On the territory of all 14 small forest catchments takes place monitoring of ecologically important elements in surface waters. Water samples are collected throughout the duration of the project in monthly intervals.

In samples are measured following parameters: Na, Ca, K, Mg, SO4, NO3, NH4, Cl, F, Mn, Fe, Zn, Al, As, Cd, Pb, Ni, DOC (Dissolved Organic Carbon) and DON (dissolved organic nitrogen), followed by pH and conductivity. The outcome is a database of substance flows for the reporting period presented in monthly intervals.

Soil chemistry

Soils are the largest storehouse of basic cations (Ca, Mg, K) and other ecologically important nutrients (P, N) in the catchment. Also the largest amount of carbon of the entire ecosystem is tied in soils. Soils were collected in 14 forested catchments on the selection based on areas defined in GIS (weighted selection based on the stand, topographic and soil characteristics of the basin).

Quantitative sampling of soils was performed, that is based on ICP Forest methodology and include quantification of individual soil layers defined as L, M, H, 0-10, 10-20, 20-40 and 40-80 cm. In each soil horizon is determined the content of exchange cations (Ca, Mg, Na, K) in the leachate 0.1M BaCl2, exchange pH (1 M KCl) and pH in the water, exchange acidity, and is calculated cation exchange capacity (CEC) and base saturation (BS).

The results are presented in the form of tabular summaries of element supplies in soils and outputs in the form of maps in the GIS environment.

Vegetation and biodiversity

In all 14 watersheds were collected samples of the assimilation organs of representative trees in the catchment. Further were taken bores of wood samples. In samples of biomass are determined total contents of Ca, Mg, K, C, N and P.

The chemistry of the surface water in the headwater areas of the Czech Republic came in the second half of the 20th century through markedly acidification, when the composition of the water (low pH, high levels of toxic Al) had a negative impact on the diversity of animals and plants (fish, macroinvertebrates, plankton, etc.). Although surface water successfully recovered from acidification, biological regeneration is delayed and its future trajectory is difficult to estimate. In the Water Framework Directive is anchored requirement phytobenthos monitoring in rivers as indicators of the ecological state of the watercourse. Composition of bioindication phytobenthos is an effective means to determine the ecological state, when especially diatoms are a good indicator of the composition of the whole community phytobenthos. To identify trophic status and degree of acidity of the environment are also used non-diatoms species of benthic algae. They are particularly suitable for determining the extent of water nutrient levels (ie. Periphyton index of trophic status PIT) and the rate of acidification (acidification index periphyton AIP).

Evaluation of dependence of diversity composition of benthic communities of phytoplankton at the water chemistry is used to estimate future changes in the diversity of primary producers and to predict which way will develop ecological status of the studied basins. This is an important aspect, because the ecological status, as defined in the Water Framework Directive, is defined by the structure and function of ecosystems, which benthic organisms are an important part.