Active Protection of Halophytes: Assessment of the Human Intervention Range using Emergy Analysis and Indicators of Sustainable Development

Anthropogenic disturbances in nature can be defined by energy and emergy terms. I studied four saline meadows with different protection status to see if they differ in species richness and plant biomass of halophytes and in the level of anthropogenic disturbance. The four studied meadows were located in the Kujawy region, the central part of Poland. The first study area was the reserve of halophytes called Ciechocinek. The others were three meadows in the valley of the River Zglowiaczka in the south-eastern part of Kujawy. The first study site is situated near graduation towers, which were built in the mid-19th century and have been used until present times to condense brine by renewable energy for the nearby salt-works. Halophilous species and their communities retreated when artificial inundations of meadows by saline waters were discontinued. Also suspension of hay-production activities and grazing of meadows contributed to a decline of halophytes. The meadows studied in the valley of the Zglowiaczka River are naturally saline by subsoil waters. The analyses were carried out there in two plots exploited for hay-production and cattle grazing (one of them intensively and the other one moderately exploited) and the third plot managed in a considerably less intensive way for extensive grazing. The aim of the analysis was to calculate the Environmental Sustainability Index (ESI) and to define whether the range of anthropogenic disturbance is comprised within the magnitude range of ESI corresponding with the systems where management is performed according to the principles of sustainable development. Among the four studied sites, the lowest ESI value (0.15) was obtained for the reserve Ciechocinek (i.e., the ecosystem with the most typical halophytic plant communities, but supported by artificial flooding with saline waters). This value was somewhat higher than values obtained for industrial systems and intensive field cultivations. The two meadows in the Zglowiaczka River valley naturally supported by saline waters, but intensively or moderately exploited reached the value of 1.12 and 1.24, respectively. The ESI of the third meadow, also naturally saline by subsoil waters and extensively grazed only, reached the value of 4.29. The high contribution of halophytes in the total number of species and the total biomass of a plant community were recorded in the intensively and moderately disturbed meadows. The lowest contribution of halophytes was recorded in the extensively grazed meadow, where strong domination of common reed Phragmites australis was observed. The ESI values of the former reserve Ciechocinek and the two more intensively exploited meadows in the Zglowiaczka River valley were lower than the values 2.7 and 3.0 stated in the ecological literature for protected areas, such as a national park or nature reserve. Among the four studied meadows, only the least disturbed (by extensive grazing) site in the Zglowiaczka River valley, with sporadic appearance of halophytic plant species, obtained a higher ESI (4.19) compared to the above mentioned values characteristic of protected areas. Chapter 8. Active Protection of Halophytes...