Spatial correlograrns of soil cover as an indicator of landscape heterogeneity

作者：Uuemaa Evelyn; Roosaare Jueri; K**** Arno; Mander Uelo^*

来源：Ecological Indicators, 2008, 8(6): 783-794.

DOI：10.1016/j.ecolind.2006.12.002

• FRAGSTATS metrics
• landscape pattern
• landscape regions
• Moran's I
• soil cover
• spatial autocorrelation

Soil cover, which is one of the most informative and integrative landscape factors, can be used for the analysis of landscape patterns. We studied the spatial autocorrelation (Moran's I) of raster format soil maps (1:10,000; 10 m pixel size) in 35 study areas representing all landscape regions in Estonia. The carbonate concentration of soils, volumetric soil moisture (%) and the depth of the groundwater table were taken into consideration in compiling a scale of contrast of 17 soil groups. We introduce a simple characteristic based on spatial correlograms: a half-value distance lag, h(1 = 0.5) - a distance where Moran's I drops below 0.5. Spatial autocorrelation decreased very rapidly in the case of heights with a very heterogeneous landscape composition, showing low values of h(1=0.5) (< 100 m in all 6 study areas). In uplands and depressions, the spatial autocorrelation also decreased relatively rapidly (h(1=0.5) < 200 m). In most of the plains, coastal lowlands, sea islands and inland paludified lowlands, the values of Moran's I did decrease slowly with increasing lag, being > 200 m in all forest and bog areas with complex topographical conditions due to the variety of glacial landforms and peatlands. All of the eight FRAGSTATS landscape metrics studied demonstrated significant correlations with h(1=0.5), whereas five of them - Contrast Weighted Edge Density (CWED); Percentage of Like Adjacencies (PLADJ), Edge Density (ED), Patch Density (PD) and Mean Patch Area Distribution (AREA_MN) - had Spearman Rank Order Correlation values higher than 0.8. Landscapes with high ED, PD, and CWED values have a low autocorrelation: PD, ED, and CWED correlated negatively with h(1=0.5). PD, ED, and CWED decreased and PLADJ increased with the power-law relationship with increasing h(1=0.5). Spatial autocorrelation is lower in landscapes with complex structure and high contrast. The positive relationship with PLADJ indicates the same. Thus, spatial correlograms of potential landscape structure based on soil cover analysis can be used for the characterization of human-influenced landscape (land use) structure.

• 出版日期2008-11