Fig. 2
From: Trees of Panama: A complete checklist with every geographic range
Latitudinal range limits of Panama’s 3043 tree species. Blue points are northern limits and green southern limits. The species are sorted by the northern limit, so the blue points form a smooth curve. Two red lines show Panama’s latitude (7.2∘−9.6∘ N), and two orange lines show the Tropics of Cancer and Capricorn (23.26∘). The gray curves show mean ± SD of the southern limit for each successive group of 200 species. The increase in the southern limit across the graph shows that species whose ranges extend further north also extend further south. The difference is strong: 21% of the leftmost 1300 species on the graph (ranges extending north of Nicaragua at 14.9∘ N) have ranges extending beyond the Tropic of Capricorn; in contrast, only 1% of the rightmost 600 species (ranges not north of Panama) extend to the southern Tropic