Spring is yet to come in parts of Europe. I spent most of April in Norway working with collaborators in Trondheim, and was impressed by how much snow still remains in the mountains. Lakes are still frozen, trees shrouded, and the high peaks buried under white cover. It is a very different landscape than the…

Spring in England means every day is longer than the one that precedes it by more than a few minutes. With the lengthening of the days comes the re-emergence of the forest. Earlier this week I went out with our research group to the canopy walkway at Wytham Woods. It is a short climb up…

Early spring is when the elevation contrasts of Britain’s mountains are clearest. These weeks I have been wandering through England and in Wales, climbing where possible, seeing what could be found among the valleys and hilltops. The transition between winter and spring means that the valleys are warm, and the hilltops are still cold, so…

The red flowers of the invasive African tulip tree (Spathodea campanulata; Bignoniaceae) stand out in a Puerto Rican rain forest. This species may occupy a mathematical hole, having an ecological strategy unoccupied by other species in the community. Recent mathematical advances now allow detection of holes and better understandings of species invasions and extinctions. Imagine…