Correlation Between Water Level, Water Chemistry and Vegetation in Alkaline Fens
Correlation Between Water Level, Water Chemistry and Vegetation in Alkaline Fens
Can you get knowledge about the water level and quality of the water in the alkaline fen by examining the plants of the alkaline fen?
This question will a new pilot project between the Danish Environmental Protection Agency and the University of Aarhus help to clarify under the auspices of NOVANA.
Previously, the water quality of the alkaline fen has been studied, for example, how loaded the water is with nutrients, via pipes tucked into the fen. But it takes many pipes and many measurements, and it is expensive if the method is to be implemented across the country.
On the other hand, if you can determine the water quality based on the composition of plants and mosses on the surface of the alkaline fen, then it is both faster and far cheaper.
The project is being implemented at eight sites in the Central Jutland and Himmerland in river valleys covered by the EU LIFE IP Natureman project.
Can the Vegetation and Nutrients in Plants Reveal Water Quality?
The new pilot project investigates how vegetation of vascular plants and mosses is related to the occurrence of pressurized water and fluctuations in the water level, as well as the content of nitrogen and phosphorus in the water and vegetation.
Hunting for Effective Method
Alkaline fen is one of the habitat directive's wet habitats, which, for example, also count petrifying springs, molina meadows, raised bogs, humid dune slacks and bog woodland, all of which depend on the amount and quality of the water they are affected by.
Hydrology is particularly important for petrifying springs and alkaline fens, which are defined by the flow of groundwater. The groundwater outflows are often unpredictable and rather local, while the affected areas may be much larger, but are often defined by ditches.
The purpose of the pilot project is to develop extensive indicators of hydrology, so that the condition and development of habitats can be assessed over time. Surveying and monitoring hydrology with water level is resource intensive and not immediately compatible with the extensive monitoring that is organized in NOVANA.
Facts About the Project
The pilot project is being carried out at eight sites with the presence of well-functioning alkaline fens in the central Jutland and Himmerland streams covered by the LIFE IP Natureman project. At each site, two sample areas are investigated, one area of the alkaline fen in optimal condition and one area of less optimal condition. The location of the water level measurements is thus defined by the vegetation and not by the geology of the area.
At the end of 2018, GEUS (Geological Survey of Denmark and Greenland) conducted a soil survey and was responsible for setting up two water level pipes at each sample area, with one pipe measuring the current water level, while the other pipe measuring the water pressure potential. The water level loggers are installed in the pipes, which continuously measure the water level fluctuations over the year.
In the summer of 2019, the Danish Environmental Protection Agency conducted vegetation analyzes of vascular plants and mosses. In addition, the pH and content of nitrogen and phosphorus in the root zone are measured three times a year, testing different methods for sampling water and taking a leaf sample of peat mosses for measuring nitrogen and phosphorus.
In 2019 vegetation analyzes have been carried out in the form of pinpoint analyzes and 5 m circles, as well as registration of structure data at each sample area. In addition, a registration of the microtopography must be made, which is of great importance for the composition of the vegetation.
The pilot project is scheduled to run over 3 years to investigate the year-to-year variation, ie. illustrate how much variation one would expect between annual measurements taken at the same time and using the same method.
The answer to whether the vegetation has potential as a future indicator of hydrology hopes that the Danish Environmental Protection Agency will arrive at when the many data collected has been analyzed after the project period, when the results are expected to be published.
Project Participants
- Henriette Bjerregaard (Danish Environmental Protection Agency, Central Jutland)
- Kamilla Harlev Mai, (Danish Environmental Protection Agency, North Jutland)
Economy
Project Period: 2018 - 2021
Project Financing:
National Funding
Project Sum: DKK 1,500,000
Contact
Henriette Bjerregaard
Danish Environmental Protection Agency, Central Jutland
mail: henbj@mst.dk
tel.: +45 72 54 38 58
mob.: +45 29 16 01 66