(B) Latitudinal transects (riverside, Figure 4, A/D/F)
Plots in transects were labelled 1-10 from the upper to the lower across 900 meters. Transect A was an open river terrace while D and F were closed. The H index was positively and significantly correlated along the river (P < 0.05 ). Compared to altitudinal transects, the water supply of transects A/D/F seemed sufficient because it was close to the river channel. Simultaneously, closed habitats were constructed in some areas in transect D and F due to developed shrubs and trees. However, transect A did not develop flourishing riverine vegetation. The main reason would be ascribed to irregular river tides.
FIGURE 4 The variance of Shannon-Wiener index (H) in transects. (Al. = Altitudinal, La. = Latitudinal)
3.3. β-diversity and the habitat heterogeneity in the valley