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利用常规土壤调查方法辨认和描述了11种土壤类型,以便分析火炬松(Pinus taeda L.)的生产力。每个土壤类型建立4个4公顷的研究地点(每个研究地点包含4个测量样地)上。利用逐步多元回归分析土壤母质层(结合下层土壤质地和地质学)和排灌级别,它们是立地指标(树龄25年)重要的预测值,整个线性回归模型的相关系数(R2)为0.55。在Wicomico-Penholoway地区的肥沃下层土与Pamlico-Princess Anne地区的黏土的土壤母质层立地指标最大相差3.9m。排灌级别的立地指标最大相差0.7m。例如,排灌差的土壤的立地指标比稍差的低0.7m。11个土壤类型中的7个土壤类型,80%以上估计的平均立地指标与实际的土壤类型平均立地指标相差±0.8m。其它4个土壤类型(标号:G,I,C和K)需要重新定义或更多地集中采样。为了精确的定性立地质量,需要对其中两个土壤类型(基于地质学的土壤类型G和基于土壤排灌级别土壤类型I)进行重新划分。土壤排灌级别的变化和上层土壤被转化为干草列的变化数量是两个影响土壤类型(C)立地质量的影响因子。第4个土壤类型K立地指标数据有很大的变化,部分原因是由于采样地点和个别测量样地的优良垫层和人工排灌设施较少。具有不同排灌级别的土壤母质层(结合下层土壤质地和地质学)是重要的卡罗莱纳州南部海岸地区的立地质量的影响因子。
Eleven soil types were identified and described using conventional soil survey methods to analyze the productivity of Pinus taeda L. Four 4-hectare study sites (4 survey plots per study site) were established for each soil type. Using stepwise multivariate regression analysis of soil parent material (combined with the underlying soil texture and geology) and the level of drainage and irrigation, they are important predictors of site index (age 25 years). The correlation coefficient (R2) of the whole linear regression model is 0.55. The maximum difference in site index of the soil parent material between the fertile subsoil in the Wicomico-Penholoway region and the clay in the Pamlico-Princess Anne region is 3.9 m. Drainage and irrigation levels of the maximum difference between the site index 0.7m. For example, the soil index for poor soil and irrigation is 0.7m lower than the slightly worse site. Among the 11 soil types, 7 of the soil types showed a difference of ± 0.8m from the average on-site index of the actual soil types in more than 80% of the estimated average site indexes. The other four soil types (labels: G, I, C and K) need to be redefined or more centrally sampled. In order to accurately characterize the site quality, two of these soil types (geology-based soil type G and soil-based drainage-type soil type I) need to be subdivided. The change of soil irrigation and drainage levels and the change of the upper soil into hay are the two influential factors that affect the site quality of soil type (C). The fourth soil type K site index data varies widely, due in part to the lack of good bedding and artificial irrigation and drainage facilities at sampling sites and individual plots. Soil parent material with different drainage and drainage levels (combined with underlying soil texture and geology) is an important factor affecting site quality in the southern coast of North Carolina.