ENVIRONMENT > For experts and partner cities > Biomonitoring of the environment
Bioindication environmental monitoring – regular monitoring of living organisms at selected localities
(the text below is based on the chapter Regular monitoring of living organisms at selected localities (bioindication monitoring) published in yearbook Prague Environment 2006)
Fig. Development of the amphibian population
Fig. Development of the reptilian population
Note: excluding the newly given species of smooth snake (Coronella austriatica)
Fig. Prokopské Valley – the number of species registered and expected classified by groups and seasons
Monitoring of the state of and development in environmental compartments follows numerous antropogeneous pollutants and provides by means of chemical and physical measurements information on their quality and quantity in the environment. In order to evaluate their affects on the territory population and on health risks the values measured can be compared to public health standards, which represent virtually contractual values that may often widely differ in various countries. Because under common conditions there is not only one factor or pollutant, yet a whole set of factors, the objective interpreting of the values measured from the hygiene point of view is substantially more troublesome, namely due to synergic effects – certain factors or components tend to reinforce effects of the others more, and in exceptional cases even a negative synergic effect or mutual neutralization may occur (acid rain combined with alkaline dust fallout from a cement plant, for instance).
The bioindication monitoring offers the approach the other way – it does not deal with causes yet with consequences of sets of pollutants in organisms, which may this way contribute to the evaluation of effects of local conditions also on human population and some of which more sensitive than human organism may in advance indicate hygiene risks to the population in the given environment.
The methodology applied: Repeated inventory taking is carried out of selected groups of plants and animals having significant ability to indicate in five model natural sites in Prague. Results are either descriptions of the actual status either finding of time series (trends) through the benchmarking with the previous monitoring periods.
Divoká Šárka Valley (1984, 1988, 1993, 1998, 2003),
Prokopské Valley (1984, 1989, 1994, 1999, 2004),
Pitkovice Valley and Uhřiněves Game Preserve (1985, 1990, 1995, 2000, 2005),
Confluence of the Vltava River and the Berounka River (1986, 1991, 1996, 2001),
Troja Valley (1987, 1992, 1997, 2002).
In 2005 the Pitkovice Valley and Uhřiněves Game Preserve were investigated. Comparing these two close areas natural communities on the Pitkovice Valley, including the small scale protected area “Pitkovice Slope” appear to have higher value and being richer; the immission load from local sources as well as by the prevailing winds from Prague is lower there than that in the Uhřiněves Game Preserve. This holds especially for liverworts that belong to sensitive bioindicators of the atmospheric pollution transfer. The increase in their number in the Pitkovice Valley indicates slight improvement in the immission conditions, it can be deduced from their species representation that there is less sulphur oxides and a slight increase in nitrogen oxides from mobile sources. The Uhřiněves Game Preserve is traditionally less rich and the species composition indicates higher immission load yet, compared to the past, even there slight revitalisation was noticed.
Bryoflora (mosses and liverworts) in the Pitkovické Valley were in the meantime in between the last inventory takings partly affected by floods in 2002, one shore growth entirely vanished, the others were broken and fragmented into small islands also due to the progress of the nettle growth supported by nitrification from the increasing amount of traffic flue gas. On the contrary, in the Uhříněves Game Preserve the qualitative and quantitative increase in the number of species was found due to the area freed by the retreating ruderal flora.
Among 30 species of molluscs found in the Pitkovice Valley one species formerly present, yet missing since 1990, appeared again. This component situation in the Game Preserve is assessed as mostly steady state, nevertheless in the partial section of the Game Preserve one new species was found. Therefore a trend to moderate environmental quality improvement is indicated on both the territories.
Rather different result was obtained by the inventory taking of butterflies in the Pitkovice Valley where already in the past the decreasing trend was indicated concerning quantity, which was slowed down in the recent period yet still occurs. One, formerly not found, species was added yet.
The Uhříněves Game Preserve remains without any significant change substantially less rich than the Pitkovice Valley.
Concerning phytophagus beetles the Pitkovice Valley is also more valuable then the Game Preserve. In the time series both the territories appear as stabilised yet with prevailing adaptable and expansive species, which are less sensitive to environmental quality.
The 144 species of Carabidae beetles (with one species more compared to the state in 2000) make the Pitkovické Valley an above average quality Prague’s locality. The Game Preserve is permanently less rich in species while adaptable and expansive species prevail and that indicates worse environmental conditions yet variable in time.
Reptiles and amphibians indicate, on the contrary to the majority of other groups, adverse trends, which are, however, not related to antropogeneous environmental pollution; in this case negative factors effective here are the growing frequency in visits and number of visitors, invasive area development in the vicinity, cycling, and free roaming dogs.
Similar sources of adverse effects were found also in birds and because this part of fauna was investigated here for the first time no development trend could have be determined so far.
The synthesis of outcomes from respective inventory takings enables to state that pollution with airborne contaminants has been slightly decreasing, except for the progress in nitrophilous plants, confirming the increase in nitrogen oxides from the growing traffic.