Spatial patterns of aboveground phytogenic Si stocks in a grass-dominated catchment – results from UAS-based high-resolution remote sensing
<p>Various studies have been performed to quantify silicon (Si) stocks in plant biomass and related Si fluxes in terrestrial biogeosystems. Most studies are deliberately designed on the plot scale to ensure low heterogeneity in soils and plant composition, hence similar environmental condition...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-09-01
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| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/18/5163/2021/bg-18-5163-2021.pdf |
| Summary: | <p>Various studies have been performed to quantify silicon (Si)
stocks in plant biomass and related Si fluxes in terrestrial biogeosystems.
Most studies are deliberately designed on the plot scale to ensure low
heterogeneity in soils and plant composition, hence similar environmental
conditions. Due to the immanent spatial soil variability, the
transferability of results to larger areas, such as catchments, is therefore
limited. However, the emergence of new technical features and increasing
knowledge on details in Si cycling lead to a more complex picture at
landscape and catchment scales. Dynamic and static soil properties change
along the soil continuum and might influence not only the species
composition of natural vegetation but also its biomass distribution and related
Si stocks. Maximum likelihood (ML) classification was applied to
multispectral imagery captured by an unmanned aerial system (UAS) aiming at the
identification of land cover classes (LCCs). Subsequently, the normalized
difference vegetation index (NDVI) and ground-based measurements of biomass
were used to quantify aboveground Si stocks in two Si-accumulating plants
(<i>Calamagrostis epigejos</i> and <i>Phragmites australis</i>) in a heterogeneous catchment and related corresponding spatial
patterns of these stocks to soil properties. We found aboveground Si stocks
of <i>C. epigejos</i> and <i>P. australis</i> to be surprisingly high (maxima of Si stocks reach values up to 98 <span class="inline-formula">g Si m<sup>−2</sup></span>), i.e. comparable to or markedly exceeding reported values
for the Si storage in aboveground vegetation of various terrestrial
ecosystems. We further found spatial patterns of plant aboveground Si stocks
to reflect spatial heterogeneities in soil properties. From our results, we
concluded that (i) aboveground biomass of plants seems to be the main factor
of corresponding phytogenic Si stock quantities, and (ii) a detection of
biomass heterogeneities via UAS-based remote sensing represents a promising
tool for the quantification of lifelike phytogenic Si pools at landscape
scales.</p> |
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| ISSN: | 1726-4170 1726-4189 |