Zs. P. Komáromy szerk.: Studia Botanica Hungarica 16. 1982 (Budapest, 1982)

Hably, Lilla: The relation between Pb-pollution along mainroads and the trace element-composition in soil and vegetation (Examination of section rectangular to M3 mainroad)

increases and remains at medium value almost still the bottom of B-level. At the depth of 1 m it increases but it reaches its maximum only between 140 and 160 cm. After that its quantity suddenly decreases and in the lowest sample it'starts increasing again. Section No. 32 is free of carbonate in its upper 80 cm. After that a gradual and even increase of the carbonate contents can be observed until its maximum of about 12% (160 and 180 cm), after which its value decreases again. The tendency of the changes in the soluble Mn, Zn, Cu, Pb can not be marked by decrease according to depth. Although all the elements show the highest concentration in the uppermost level, the level between 80 and 100 cm is also very near the above values. Zn is the element whose quantity suddenly decreases below A-level and remains on this low level to the bottom of the section with minor variations. Also in this section it is Cu which shows a downward decrease most evenly. It is interesting to note the variations of the values in lead and manganese, which show similar changes. These suddenly decrease after their highest values in A-level, increasing significantly at 60 cm and almost reaching their maximum in A-level between 80 and 100 cm. After that they show a gradual and then a quick decrease in quantity. Section No. 33 (Fig. 5) The A-level is between 0 and 20 cm, B-level is between 20 and 120 cm. Like with the previous section, the pH covers almost two and a half pH intervals, A-level is milder acidic and shows sudden decrease after its 6 pH, although it remains within acidic interval, it is already near neutral chemical reaction. Between 40 and 100 cm it is neutral. Though once it shows alkaline reaction. Under 1 m it suddenly increases and shows steady increase further on to its 8.5 pH maximum between 180 and 200 cm. The decrease in organic material content towards the deeper layers shows two stages. It is present in largest quantities in A-level, then gradually decreases to its minimum between 80 and 100 cm. It increases again to its previous quantity in about 40 and 60 cm. From here it shows steady decrease to the bottom of the section. The quantities of Illite within the section change rather capriciously, but the changes show no outstanding values. Illite appears in the section at 21-33%. It shows even changes only in the C-level, where it increases steadily from the top to the bottom of the section. Almost to the depth of 1 m the section is free of carbonate, smaller quantities of carbonate occur between 60 and 80 cm. Its quantity is relatively constant under 100 cm and shows a sudden increase in the lowest sample level (190 cm). The changes in the soluble trace element content are highly different from those in the previous section. Although copper and lead are enriched the most in the A-level, zinc reaches its maximum at the bottom of B-level (100-120 cm), and manganese reaches its maximum in the Clevel (160 and 180 cm). It is to be noted, however, that they almost reach these values also in the A-level. Zn shows the most unepected results. In the sections so far presented it remained at constantly low values under the A-level. Here this applies only to a depth of 1 m. Between 100 and 120 cm it increases again to a higher value than in A-level and occurs in a relatively high concentration in the following 60 cm. Its concentration shows again significant decrease. Section No. 34 (Fig. 6) The depth of this section is half of the previous ones (1 m). A-level is between 0 and 20 cm, beneath that the whole section is B-level. The majority of the sampling levels fall within acidous pH intervals. The 5.25 pH of A-level can be said acidic enough. Under 20 cm it is mildly acidic, at 80 cm it is very near neutral, but shows alkalescent character (7.2 pH). In this section the organic material content shows very regular variations. The maximum of A-level (4.8%) is followed by a gradual decrease with a more marked decrease under 60 cm while it reaches 2% minimum between 80 and 100 cm. Within 21 and 25% Illite changes irregularly. No carbonate mineral was present in the full length of the section. In the soluble Mn, Zn, Cu, Pb quantities, a decreasing tendency according to depth can be observed. It is remarkable, however, that while so far the order was Mn Pb Cu Zn, now Cu and Zn change places. Besides Zn is enriched not in A-level but between 40 and 60 cm, and it decreases to its usual quantity only between 80 and 100 cm under 1 ppm. To the end of the section copper occurs only in a very small quantity.