近几年美国森林测定技术的新发展有以下几点:(1)正在大量供应的分离影像测树器的改进;(2)按树干(Stemwise tree)抽样和3P抽样相结合进入多阶设计;(3)航空像片用于按面积(areawise)的可变概率抽样和测树;(4)对独立权属或全林区用多阶可变概率抽样估计净生长量、利用量和死亡率;(5)为了按材质标准级把材积、表面积(surface)和长度换算为产品利用率, In recent years, new developments in forest measurement technology in the United States have been made as follows: (1) improvement of the segmented image tree-catcher that is in large supply; (2) combination of Stemwise tree sampling with 3P sampling into multi-stage design; (3) aerial photographs for variable area sampling and tree-finding; (4) estimation of net growth, utilization and mortality using multi-stage variable probability sampling of independent tenure or whole forest area ; (5) In order to convert the volume, surface and length into product utilization by material grade,