Upper row: Distribution of galaxies in clusters and in their environment in the plane of the sky. Left: A1656. Middle: A1367. Right: A1185. Symbols of different colours show galaxies in different components of the cluster: the redder the colour, the higher the median values of the D_n(4000) index of galaxies are in a component. Black crosses show galaxies of short filaments ($F_{\mathrm{len}}^{\mathrm{s}}\le 5h^{-1}$ Mpc), and dark blue crosses show galaxies in long filaments ($F_{\mathrm{len}}^{\mathrm{l}}>5h^{-1}$ Mpc). Dark red circles show clusters from WH24m catalogue. Circle sizes are proportional to the number of galaxies in a cluster. Orange circles show the regions of influence, with R_inf. Middle row: Distribution of the clustercentric distances, D_c (upper panels), and the PPS diagram (lower panels). Symbols are as in the upper panels. Vertical lines show the cluster radius, R_cl, and the radius of the sphere of influence, R_inf. In the lower panel, the dark blue region is the early infall region, and light blue is the late infall region. Lower row: Density contrast, δρ, versus clustercentric distance. Vertical line shows the radius of the sphere of influence, R_inf, and horizontal lines mark the characteristic density contrasts, as shown in the Figure. The blue area shows turnaround region, and the light blue area shows future collapse region.