KALK

Calcium availability in soil and humus : limitations of machine-learning driven mapping

NGU-RAPPORT
2024.003
Publikasjonstype
Utgivelsesår
2024
ISSN
0800-3416
Prosjektnr
390800
Summary
Calcium (herein a proxy for lime) is an important nutrient for plants and its availability within an area can
favour the occurrence and/or dominance of certain plant species. Regional and local scale studies were
carried out in the northern Trøndelag county to assess calcium availability in different media (soil, humus,
and water) and within areas located below and above the marine limit. This study used stream water (only
regional), humus, and mineral soil data to quantify the availability of calcium. These datasets were combined
with the previously defined calcium availability index for bedrock units to elaborate an integrated calcium
availability map using Fuzzy Logic and Index Overlay approaches.
Calcium availability in soil and humus from areas below and above the marine limit are undistinguishable.
The stream water samples located below the marine limit are slightly enriched in calcium relative to those
taken above, but this is likely due to contamination derived from nearby farming. Notably, the spatial
correlation between calcium in humus and bedrock is greater than that of calcium in soil and bedrock
regardless of the survey scale. This suggests that for some elements, humus may be a better media to
characterize the underlying lithologies, which may have important implications for mineral exploration
surveys and environmental assessments. Our methodology is validated by the fact that in both surveys
(regional and local), lime-rich forest types were mainly contained in areas having intermediate to high calcium
availability values in different media and the integrated calcium availability map. Despite its limitations, the
methodology described in this study provides a first order tool to identify forest types that commonly occur
in areas with low and high calcium availability.
Forfattere
Acosta-Gongora, Pedro
Wang, Ying
Finne, Tor Erik
Taftø, Siw
Heldal, Tom
Fylke
TRØNDELAG
Tilgjengelig
NGU-biblioteket

Ikke-metalliske mineralressurser i Røyrvik kommune, Nord-Trøndelag fylke

NGU-RAPPORT
99.131
Publikasjonstype
Utgivelsesår
1999
ISSN
0800-3416
Prosjektnr
284200
Summary
Etter ønske fra Joma Næringspark har ikke-metalliske mineralske ressurser blitt undersøkt i Røyrvik kommune. Undersøkelsene omfatter naturstein, kalk, kvartsitt, talk og grafitt. De tre sistnevnte ressurstyper er av såpass lav kvalitet/kvantitet at videre undersøkelser ikke anbefales, mens det er anbefalt oppfølgende undersøkelser av enkelte objekter på naturstein og kalk.
Forfattere
Karlsen, T.A.
Kjølle, I.
Wanvik, J.E.
Øvereng, O.
Heldal, T.
Kommune
RØYRVIK
Fylke
TRØNDELAG
Tilgjengelig
NGU-biblioteket
Prosjekt
Mineralressurser i Røyrvik

Lime availability in soil, humus, and water

NGU-RAPPORT
2021.034
Publikasjonstype
Utgivelsesår
2021
ISSN
0800-3416
Prosjektnr
390800
Summary
Calcium (herein a proxy for lime) is an important nutrient for plants and its availability within an area can
favour the occurrence and/or dominance of certain plant species. Regional and local scale studies were
carried out in the northern Trøndelag county to assess calcium availability in different media (soil, humus,
and water) and within areas located below and above the marine limit. This study used stream water (only
regional), humus, and mineral soil data to quantify the availability of calcium. These datasets were combined
with the previously defined calcium availability index for bedrock units to elaborate an integrated calcium
availability map using Fuzzy Logic and Index Overlay approaches.
Calcium availability in soil and humus from areas below and above the marine limit are undistinguishable.
The stream water samples located below the marine limit are slightly enriched in calcium relative to those
taken above, but this is likely due to contamination derived from nearby farming. Notably, the spatial
correlation between calcium in humus and bedrock is greater than that of calcium in soil and bedrock
regardless of the survey scale. This suggests that for some elements, humus may be a better media to
characterize the underlying lithologies, which may have important implications for mineral exploration
surveys and environmental assessments. Our methodology is validated by the fact that in both surveys
(regional and local), lime-rich forest types were mainly contained in areas having intermediate to high calcium
availability values in different media and the integrated calcium availability map. Despite its limitations, the
methodology described in this study provides a first order tool to identify forest types that commonly occur
in areas with low and high calcium availability.
Forfattere
Acosta-Gongora, Pedro
Finne, Tor Erik
Flem,
Belinda
Andersson, Malin
Heldal, Tom
Fylke
TRØNDELAG
Tilgjengelig
NGU-biblioteket