Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...

a Spatial pattern of tree numbers within a 0.01° grid. b Latitudinal distribution of tree density and total tree numbers, with shaded areas indicating the standard deviation of the estimated tree ...

Look up at the night sky and you might feel dwarfed by the glimmer of countless stars. Now shift that view downward, press your mind to the ground and the green world under your feet—and you’ll find ...

a Spatial pattern of tree numbers within a 0.01° grid. b Latitudinal distribution of tree density and total tree numbers, with shaded areas indicating the standard deviation of the estimated tree ...