Fig. 4
From: Campanula lingulata populations on Mt. Olympus, Greece: where’s the “abundant centre”?
Probability density functions of the number of individuals in the altitudinal range 300–1300 m for a 2012 and b 2013. Each successive density curve corresponds to an elevation class. X-axis describes the density of individuals in a 20 × 20 m square, while y-axis denotes the probability of acquiring said density through random stratified sampling within each elevation zone. Numbers 1–10 for elevation classes are as described in Fig. 3