The transition from the Medieval Climate Anomaly (MCA, 950-1250 CE) to the Little Ice Age (LIA, 1350 to 1800 CE) is the largest pre-industrial climate shift within the last two millennia, offering an opportunity to study how vegetation responds to rapid climate change. We analyzed a sedimentary record from the Colombian Andes to reconstruct regional vegetation dynamics during this time interval, identify the modern environmental distribution of taxa present in the fossil record, and provide...

Quantifying global patterns of terrestrial nitrogen (N) cycling is central to predicting future patterns of primary productivity, carbon sequestration, nutrient fluxes to aquatic systems, and climate forcing. With limited direct measures of soil N cycling at the global scale, syntheses of the 15N:14N ratio of soil organic matter across climate gradients provide key insights into understanding global patterns of N cycling. In synthesizing data from over 6000 soil samples, we show strong global relationships among...