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您的检索式：作者名="Wendell P.Cropper"
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| 1 | Estimating Pinus palustris tree diameter and stem volume from tree height,crown area and stand-level parameters显示文摘Accurate and efficient estimation of forest growth and live biomass is a critical element in assessing potential responses to forest management and environmental change.The objective of this study was to develop models to predict longleaf pine tree diameter at breast height(dbh)and merchantable stem volume(V)using data obtained from field measurements.We used longleaf pine tree data from 3,376 planted trees on 127 permanent plots located in the U.S.Gulf Coastal Plain region to fit equations to predict dbh and V as functions of tree height(H)and crown area(CA).Prediction of dbh as a function of H improved when CA was added as an additional independent variable.Similarly,predictions of V based on H improved when CA was included.Incorporation of additional stand variables such as age,site index,dominant height,and stand density were also evaluated but resulted in only small improvements in model performance.For model testing we used data from planted and naturally-regenerated trees located inside and outside the geographic area used for model fitting.Our results suggest that the models are a robust alternative for dbh and V estimations when H and CA are known on planted stands with potential for naturally-regenerated stands,across a wide range of ages.We discuss the importance of these models for use with metrics derived from remote sensing data. | C.A.Gonzalez-Benecke Salvador A.Gezan Lisa J.Samuelson Wendell P.Cropper Daniel J.Leduc Timothy A.Martin | 2014 | Journal of Forestry Research2014，25，1： | 12 |
| 2 | 应用遥感、人工神经网络叶面积模型和模拟过程模型估计湿地松人工林碳储量(英文)显示文摘全球气候变化引起人们对森林碳固定作用的关注。碳存储速率依赖于生态系统流通量(光合作用和生态系统呼吸),量化为净生态系统二氧化碳交换。在没有密集采样点的情况下,我们需要采用估测森林净生态系统交换的方法准确地估计林分水平和更大尺度的碳固定量。本文通过祸合遥感估算的叶面积指数和生长过程拟合模型,估计了佛罗里达州内9 770公顷湿地松人工林一年里净生态系统交换总量。地面图神经网络模型和陆地卫星数据估计的森林叶面积指数平均值是1.06(数值范围0-3.93,包括森林边界)。输入神经网络叶面积指数值,湿地松拟合模型(SPM2)估计的森林净生态交换值在-5.52 Mg·hm-2·a-1到11.06Mg·hm-2·a-1之间,平均值是3.47 Mg·hm-2·a-1。年总的碳储量是33920t,约合3.5 t/hm2。估计的叶面积指数和森林净生态交换均对对施肥高度敏感。图3表1参30。 | Douglas A.Shoemaker Wendell P.Cropper Jr | 2010 | Journal of Forestry Research2010，21，2： | 4 |
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