Epsilon Archive for Student Projects

Abstract

Syftet med denna studie är att undersöka om bioindikatorerna skogssork (Myodes glareolus), vanlig näbbmus (Sorex araneus) och brun skogssnigel (Arion subfuscus) ackumulerar tungmetaller efter gödsling av skog med värmebehandlat och pelleterat eller granulerat avloppsslam. Försöksområdet ligger nära Bäcksjön, Umeå, i Västerbottens län. Det dominerande trädslaget är tall (Pinus sylvestris) med inslag av gran (Picea abies), skogstypen är blåbärsristyp på frisk mark. I maj 2003 anlades ett replikerat randomiserat blockförsök med slampellets och slamgranuler i olika doser, samt kontrollytor. Behandlingsytorna var 46 x 46 meter. Doseringen för pelleterat slam från Umeås reningsverk var 5,3 ton/ha, 6,4 ton/ha och 16,1 ton/ha. Granulerat slam från Himmerfjärdens reningsverk, Stockholm, spreds i doserna 4,5 ton/ha och 13,6 ton/ha. Ett kompletterande försök med behandlingsytor om ett hektar vardera lades ut i juni 2006. Detta försök innefattade försöksleden 12 ton/ha (granulerat slam från Himmerfjärdsverken), samt kontroll, och hade tre upprepningar.
Fångst av bioindikatorer skedde under augusti månad 2006. Njurar från skogssork och vanlig näbbmus, samt hela skogssniglar, analyserades med avseende på tungmetallkoncentrationer.
Resultaten visar få signifikanta skillnader mellan behandlingarna för skogssork och vanlig näbbmus. För brun skogssnigel däremot visar resultaten på förhöjda halter av flertalet ämnen. Anmärkningsvärt för samtliga bioindikatorer är att signifikant skillnader för Cd och Pb visar lägre halter efter gödsling jämfört med kontroll. Som kovariat vid ANOVAn användes kroppsvikten för bioindikatorerna, denna visar på flertalet negativa samband. Speciellt tycks B, Si och Sn minska med ökad kroppsvikt för samtliga bioindikatorer. För vanlig näbbmus tycks även V minska med ökad kroppsvikt.

The purpose with the study was to determine whether or not there is any bioaccumulation of
heavy metals after fertilising with pelletized or granulated dried sewage sludge. For this
purpose, three bioindicators were sampled, i.e. Myodes glareolus (bank vole), Sorex araneus
(common shrew) and Arion subfuscus (dusky slug).
The experimental site is situated within the boreal forest zone near Bäcksjön, Västerbotten County. In May 2003 ten plots (46 x 46 meter) were fertilised with different doses of pelletized and granulated sewage sludge and two additional plots were selected as controls. Another trial was established in early June 2006 when three large plots (100 x 100 meter) were selected for fertilising with sludge granules and three were selected as controls.
In this study the analyses of kidneys from bank vole and common shrew show no consistent accumulation of heavy metals after fertilising with sewage sludge. Dusky slug on the other hand had significantly higher concentrations of several elements from fertilised plots. All significant results with Cd and Pb showed a lower concentration from Fertilised plots compared with Control plots. With bodyweight as a covariate several negative correlations were found. In common for all bioindicators is that B, Si and Sn seem to decrease in concentration with higher bodyweight. For common shrew also V seems to decrease with higher bodyweight.

The purpose with the study was to determine whether or not there is any bioaccumulation of
heavy metals after fertilising with pelletized or granulated dried sewage sludge. For this
purpose, three bioindicators were sampled, i.e. Myodes glareolus (bank vole), Sorex araneus
(common shrew) and Arion subfuscus (dusky slug).
The experimental site is situated within the boreal forest zone near Bäcksjön,
Västerbotten County. In May 2003 ten plots (46 x 46 meter) were fertilised with different
doses of pelletized and granulated sewage sludge and two additional plots were selected as
controls. Another trial was established in early June 2006 when three large plots (100 x 100
meter) were selected for fertilising with sludge granules and three were selected as controls.
In this study the analyses of kidneys from bank vole and common shrew show
no consistent accumulation of heavy metals after fertilising with sewage sludge. Dusky slug
on the other hand had significantly higher concentrations of several elements from fertilised
plots. All significant results with Cd and Pb showed a lower concentration from Fertilised
plots compared with Control plots. With bodyweight as a covariate several negative
correlations were found. In common for all bioindicators is that B, Si and Sn seem to decrease
in concentration with higher bodyweight. For common shrew also V seems to decrease with
higher bodyweight.