Spectral determinants of biological soil crusts in the Gurbantungut Desert
- Author:
- Wang Z., Wu B., Ma Z., Zhang M., Zeng H. & Yang L.
- Year:
- 2023
- Journal:
- International Journal of Remote Sensing
- Pages:
- 44(7): 2273–2293
- Url:
- https://doi.org/10.1080/01431161.2023.2198653
As thick crustal layers form on dryland surfaces, they affect the
spectral information that is originally dominated by sand or rock.
The spectral characteristics of organic matter replace the mineral
elements as prominent features. In this case, the growth patterns
and spectral characteristics of biological soil crusts (BSCs) can be
observed. Satellite spectral data have been used for BSC spatial
information extraction. However, the dynamic changes in BSCs can
affect the spectra. Two aspects are involved here: moisture change
and BSC growth. When these changes are superimposed with BSC
succession, they lead to an increase in spectral complexity. This study
explored three BSC types, including algal crust, lichen and moss, and
discussed their spectra. By selecting BSC samples at different succession
states and by combining coverage and simulated precipitation,
the response of the spectra to BSC coverage and the spectral characteristics
of BSCs under dry and wet conditions were measured and
analysed. In addition, the spectral index variations caused by coverage
and moisture of three types of BSCs were discussed, where the
spectral indices include the normalized difference vegetation index
(NDVI), brightness index (BI), crust index (CI), and biological soil crust
index (BSCI). The results showed that the succession, moisture and
growth of BSCs were the main factors affecting their spectra. BSC
types can be distinguished in a particular climatic context to determine
the degree of BSC succession. Precipitation in the monitoring
areas needs to be considered to avoid the effects of dry and wet BSC
variations on remote sensing monitoring. The coverage of different
types of BSCs in mixed pixels can be determined by multiple indices.
The results of this study will provide a basis for monitoring BSCs using
satellite spectral information to guide regional ecological
management.
Keywords: Biological soil crusts; spectral
information; growth;
succession; moisture;
spectral indices.
- Id:
- 35453
- Submitter:
- zpalice
- Post_time:
- Wednesday, 24 May 2023 11:46