Imagine being in a skyscraper. Close the windows, and would you still be able to tell if you were on the first floor or the hundredth? Forest canopies are different – the top and bottom are entirely different world. Let’s go on a tour of Puerto Rican moist tropical forest, and climb twenty or thirty…

William Blake once wrote a poem, “The Little Girl Lost”, about two parents searching for their child through valley and desert. This week I have returned to Puerto Rico, on a much less pressing errand – the resurvey of a forest for the second year of a five-year study on forest dynamics. Last year, our…

You might imagine that the life of an ecologist is spent mostly in beautiful and remote places. While this is sometimes true, a large fraction must also be spent in front of a computer. The reason is that science is only partially about making measurements or doing experiments. These parts are the glamorous ones, insofar…

Cold depends so much on context. In the last two weeks, I’ve experienced two different winters separated by thirty degrees of latitude – Rondane National Park, in central Norway (62 °N), and now Tucson, in Arizona in the lower United States (32 °N). The experience has made me think more about how organisms (people included)…