Figure 4. Relationships between species density (richness/area) and
distance downstream (blue points & line) and cumulative richness (black
line) for (a) Hjuksån and (b) Bjurbäcken. Species density regressions:
Hjuksån (p = 0.0471, R2 = 0.21), Bjurbäcken (p =
0.694, R2 = 0.009). Relationships between similarity
between vegetation communities and distance between all reaches for (c)
Hjuksån and (d) Bjurbäcken. Linear regression: Hjuksån
(R2 = 0.05, p = 0.003), Bjurbäcken
(R2 = 0.092, p < 0.001).