1. Soils and Biogeochemistry Graduate Group, Department of Land, Air and Water Resources University of California, Davis Davis CA USA
2. Environmental Studies Program, Department of Geography, Institute of Ecology and Evolution University of Oregon Eugene OR USA
3. Now at Climate and Ecosystem Sciences Division Lawrence Berkeley National Laboratory Berkeley CA USA
4. Laboratório de Ecologia Vegetal Universidade do Estado de Mato Grosso, Campus de Nova Xavantina Nova Xavantina Brasil