Results
When the areas in an ecosystem are sorted into the heterogeneous, transitional and homogeneous according to the low, middle and high EGUS value, the results of simulation showed that species richness is often the highest in the area with a middle EGUS value, followed by those in the area with a high value, and lastly, in the area with a low value. The area with a high EGUS value is the highest only when the environmental stress levels are very high in these areas (Table 1). The second simulation method revealed a unimodal relationship between species richness and EGUS (Fig. 1).
The investigation also showed a unimodal algal richness-water EGUS value relationship (Fig. 2). After the locations were matched with local MoranI (\(I_{i}\)) values, the results showed that the EGUS of water in the middle layer of the lake is the highest, followed by that of the shallow layer, and lastly, that of the deeper layer. The algal richness of the middle and deeper layers decrease by about 5% and 12% compared to that of the shallow layer, respectively. The EGUS of the river section closest to a city is the highest, followed by that of the section closest to a dam, and lastly, that of the section passing by the city. The algal richness in the river section closest to the city and the section passing by the city decrease by about 9% and 26% compared to that of the section closest to the dam, respectively.