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998. Occurrence and spatial pattern of water repellency in a beech forest subsoil

Creator:
Bachmann, Jörg, Krueger, Jiem, Goebel, Marc-O., and Heinze, Stefanie
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
beech forest, soil organic carbon, subsoil, and water repellency
Language:
Slovak
Description:
Most recent studies on soil water repellency (WR) were limited to the humous topsoil or to shallow subsoil layers slightly below the main root zone to approximately 0.5 m depth. Hence, the main objective of the present study was to investigate the wettability pattern of a forest soil including the deeper subsoil. The selected site was a 100 years old beech forest on a well-drained sandy Cambisol in northern Germany which showed moderate to partly extended acidification. Results obtained from three sampling transects (3 m length, 2 m depth; sampling grid 8 × 8 samples per transect; minimum distance of sampling locations to nearest tree about 0.5 m) show that contact angles (CA) were always in the subcritical WR range (0° < CA < 90°). Significant impact of the tree distance on WR was not observed for any of the transects. A prominent feature of two transects was the minimum WR level (CA < 10°) for samples with soil organic carbon (SOC) contents around 0.25-0.4%. For the topsoils it was observed that CA increased with SOC content from that minimum to a maximum CA of 60-75° for transects 1 and 2 with mean pH values < 3.5. For transect 3 with slightly higher average pH close to 4.0, average CA of samples were always < 10° and showed no trend to increase with increasing SOC content or other soil parameters like N content or C/N ratio. Subsoil samples, however, behave differently with respect to SOC: for these samples, generally low in SOC, the CA increase with decreasing SOC occurred at all transects for approximately 50% of the samples but did not show any clear tendencies with respect to further parameters like texture, pH or N content. We conclude that the SOC content is the most prominent parameter determining wettability, either positively correlated with WR for topsoils or negatively correlated for subsoil samples very low in SOC. We finally conclude for moderately acid beech forest stands that emerging WR starts in the A horizon after reaching a pH lower than 3.5, whereas subsoil WR might appear already at higher pH values. Even SOC contents of ∼0.01-0.02% turned out to be very effective in increasing the CA up to 70°, which points out clearly the importance of small amounts of soil organic matter in affecting subsoil wettability. With respect to site hydrology we conclude that ongoing acidification as well as predicted higher frequencies of extended droughts due to climate change will promote the occurrence of WR with corresponding implications for site and catchment hydrology.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

999. Occurrence of selected organochlorine pesticide residues in surface sediments from the Velke Kozmalovce, Ruzin, and Zemplinsk Sirava water reservoirs, Slovakia

Creator:
Hiller, Edgar, Sirotiak, Maroš, Tatarková, Veronika, and Jurkovič, Ľubomír
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
organochlorine pesticides, DDT, surface sediments, water reservoir, organic matter, organochlórované pesticídy, dnové sedimenty, vodná nádrž, and organická hmota
Language:
Slovak
Description:
Surface sediment samples from three water reservoirs of Slovakia were analyzed for selected organochlorine pesticides (OCPs). Concentrations of total dichlorodiphenyltrichloroethanes (ΣDDTs) in the sediments from Velke Kozmalovce, Ruzin, and Zemplinska Sirava ranged from 12 to 24 ng g-1, 5 to 28 ng g-1, and 1 to 20 ng g-1, respectively, with the exception of one sediment sample from Zemplinska Sirava, having anomalously high concentration of ΣDDTs (526 ng g-1). Concentrations of hexachlorobenzene (HCB) in the sediments from these water reservoirs were generally lower and ranged from 0.3 to 9 ng g-1. Other organochlorine pesticides such as mirex, lindane and heptachlor were not detected in the surface sediments. Ratios of DDT/(DDE + DDD) were lower than 1.0 in majority of the sediment samples indicating that the degradation of the parent DDT occurred significantly and DDT in the sediments from the studied water reservoirs was derived mainly from the weathered agricultural soils. Moreover, ratios of DDD/DDE indicated that the parent DDT was degraded under aerobic conditions before depositing into the sediments of these water reservoirs. and V štúdii boli analyzované vzorky sedimentov z troch vodných nádrží Slovenska na vybrané organochlórované pesticídy (OCPs). Koncentrácie sumy DDT a jeho metabolitov DDE a DDD (ΣDDTs) v sedimentoch z vodných nádrží Veľké Kozmálovce, Ružín a Zemplínska Šírava sa nachádzali v intervale od 12 do 24 ng g-1, od 5 do 28 ng g-1 a od 1 do 20 ng g-1, s výnimkou jednej vzorky sedimentu zo Zemplínskej Šíravy, ktorá vykazovala anomálne vysokú koncentráciu ΣDDTs (526 ng g-1). Koncentrácie hexachlórbenzénu (HCB) v sedimentoch z týchto vodných nádrží boli všeobecne nižšie a pohybovali sa v intervale od 0,3 do 9 ng g-1. Iné v sedimentoch sledované organochlórované pesticídy ako mirex, lindán a heptachlór neboli zistené. Vo väčšine vzoriek sedimentov boli hodnoty pomeru DDT/(DDE + DDD) nižšie ako 1, z čoho sa dá usúdiť, že väčšia časť pôvodne prítomného DDT sa rozložila na jeho hlavné metabolity a že DDT v sedimentoch vodných nádrží pochádza najmä z erodovaných poľnohospodárskych pôd. Hodnoty pomeru DDD/DDE ukázali, že predtým ako bol DDT deponovaný do sedimentov vodných nádrží, rozkladal sa najmä za aeróbnych podmienok.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1000. Odhad intercepcie v experimentálnych mikropovodiach ÚH SAV so smrekovou a hrabovou monokultúrou

Creator:
Miklánek, Pavol and Pekárová, Pavla
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Strazov highland, experimental microbasins, interception, spruce and hornbeam forest, Strážovská vrchovina, experimentálne mikropovodia, intercepcia, and smrekový a hrabový porast
Language:
Slovak
Description:
In the first part the paper gives an overview of the research activities in experimental microbasins of the Institute of Hydrology of the Slovak Academy of Science (IH SAS) in Strážov highlands during 47-years period of the years 1958 - 2005. The present state of the research in experimental basins is discussed. Due to current personal and financial situation it is time to re-evaluate and decide if operation of such experimental field base is still bearable for the institute. In the second part of the paper, the monthly interception of two catchments with different forest cover is estimated with simple regression relationships. The interception of the hornbeam forest in Lesný basin was monitored during the vegetation seasons 1981 - 1990. Its values were between 12.4 - 23.0 %. The hornbeam vegetation catches 18.4 % of precipitation in average. The interception of the spruce vegetation (Cingeľová basin) was between 30.2 - 40.8 % in 1981 - 1990 with the mean value of 36.9 %. Concerning the monthly values the highest mean interception in hornbeam forest was in June - 20.7 mm, and the lowest one in October - only 7.8 mm. In the spruce forest the interception was higher, in June it was 38.8 mm, in October 16.6 mm in average. Generally the results show that the monthly interception of the hornbeam forest is only 48 % of the spruce forest interception. and Prvá časť príspevku uvádza prehľad výskumných aktivít v experimentálnych mikropovodiach Ústavu hydrológie SAV v Strážovskej vrchovine za 47-ročné obdobie 1958-2005 a stručný opis súčasného stavu výskumu v Prírodnom hydrologickom laboratóriu (PHL). Súčasná personálna a finančná situácia pracoviska si vyžaduje zhodnotenie možností a prijatie rozhodnutia o pokračovaní existencie takéhoto detašovaného pracoviska a zabezpečenia výskumu v ňom. V druhej časti článku sú na základe meraných údajov intercepcie odvodené jednoduché regresné vzťahy umožňujúce odhadnúť mesačnú intercepciu v povodiach s hrabovou (povodie Lesný) a smrekovou (povodie Cingeľová) monokultúrou. Podkorunné zrážky v experimentálnych mikropovodiach Lesný a Cingeľová (a stok po kmeni v hrabovom poraste) boli pozorované v dennom kroku vo vegetačných obdobiach rokov 1981-1990. Hodnoty intercepcie vegetačného obdobia hrabového porastu sa pohybovali v rozmedzí 12,4-23,0 %. V priemere hrabový porast zachytáva 18,4 % zrážok. Intercepcia vegetačného obdobia smrekového porastu sa pohybovala medzi 30,2-40,8 % s priemernou hodnotou 36,9 %. Najvyššia priemerná mesačná hodnota intercepcie v hrabovom lese bola v júni - 20,7 mm a najnižšia v októbri - iba 7,8 mm. V smrekovom lese boli hodnoty intercepcie vyššie, v priemere v júni 38,8 mm a v októbri 16,6 mm. Vo všeobecnosti mesačná intercepcia hrabového porastu vegetačného obdobia dosahuje iba 48 % intercepcie smrekového porastu.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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