Results of ecological research in the area of the National Astronomical Observatory Rozhen

Diana Malinova and Ludmila Malinova

Abstract: The aim is to present results of ecological research in the area of the National astronomical observatory “Rozhen”, to evaluated the chemical status of soils and predict possible changes over time. The ecological research, conducted in the region of Rozhen – Central Rhodopes, near the National Astronomical Observatory “Rozhen”, revealed a degradation process in the dystric Cambisols from the high mountain zone at an altitude of 1750 m. The soil-forming process occurred on a strongly rugged relief and acidic silicate rock – gneiss, at an average annual temperature of 3.50°C. The tree stands are of natural origin – Picea abies (L.) Karsten. The dominant soil-forming process was a progressive acidification – the рНCaCl2 values varied in the range from 3.98 to 4.83. The analysis showed that the vertical migration of basic cations exceeded the soil profile depth. Their values were high only in the forest litter, while in the surface 5 cm mineral layer the cations sharply decreased – 4 times for the exch. Ca and 2 times for the exch. Mg, respectively. The contents of exch. K and Na were also significantly decreased. The degradation process was also represented by changes in the cationic capacity. It was determined that the еxch. Al occupied 26 % of the soil cationic capacity in the layer 0-5 cm, 73 % in the layer 5-10 cm, 85 % in the layer 10-20 cm, 81 % in the layer 20-40 cm, and 86 % in the layer 40-80 cm, respectively. The mobility of microelements was high, and the content of Cu in the forest litter was evaluated as increased above the toxicity level. The soil-forming processes led to soil depletion and the progressive acidification was defined as the main risk factor. It was assumed, that this is a naturally occurring process due to the lack of industrial sources of immissions in the area. The high acidity was assessed as a risk factor which should be monitored over time.

Keywords: cation exchange capacity; ecological research; forest soil; landscape; spruce

Date published: 2022-10-11