W. J. Rietveld

• Agroforestry and sustainable systems
• Direct seeding ponderosa pine on recent burns in Arizona
• Mulching planted ponderosa pine seedlings in Arizona gives mixed results
• North American agroforestry
• Phytotoxic grass residues reduce germination and initial root growth of ponderosa pine
• Agroforestry & Sustainable Systems
• An inexpensive truck-mounted ladder for inspecting conelet development and collecting cones
• An integrated technique for evaluating root growth potential of tree seedlings
• An integrated technique for evaluating root growth potential of tree seedlings
• Biologische ritmen
• Cone maturation in ponderosa pine foliage scorched by wildfire
• De Biologische klok