Hitchiti loblolly pine growing space study

In 1949, a loblolly pine growing space study was established on the Hitchiti Experimental Forest in Georgia as a planned part of a regional growing space study. It is unknown if the rest of the locations were ever established. The study on the Hitchiti was established in even-aged loblolly pine stands of many age classes and densities. This study involved measurements for 72 plots taken roughly every five years by the original research organization through 1983 and then by the current author's unit in 1993 and 2002. Data include plot level information such as location, soil type, stand density as well and basal area both before and after thinning. Measurements throughout the duration of the study have varied across the years, but include tree level information such as species, location, diameter at breast height, tree height, height to base of live crown, crown class, and height of the tree to a 4- or 8-inch top. However, in the early years only expected crop trees were assigned numbers so individual tree growth can only be charted by matching trees based on tally order and diameter.The study was established to study the relationship between growing space and yield as a function of three variables: age, site, and growing space.

1949年，一项针对火炬松（loblolly pine）生长空间的研究作为区域生长空间研究的规划组成部分，在佐治亚州的希奇蒂试验林场（Hitchiti Experimental Forest）正式启动。目前尚不清楚其余研究点位是否曾完成设立。
该希奇蒂林场的研究设置于多个不同龄级、密度各异的同龄火炬松林分中。该项研究的原始团队于1983年前大致每5年对72块样地开展一次测量，后续则由本文作者所在团队分别于1993年与2002年完成测量。
数据集包含样地级调查信息，如样地位置、土壤类型、林分密度以及间伐前后的林分断面积。研究周期内的年度测量内容存在一定差异，但均涵盖林木级调查信息，包括树种、林木位置、胸径、树高、活枝下高、冠级，以及树高至4英寸或8英寸梢头的高度。不过在研究早期阶段，仅对预期保留木进行了编号标注，因此单木生长历程仅能通过清点顺序与胸径匹配进行回溯。
本研究旨在探究生长空间与产量之间的关联关系，该关系以龄级、立地条件与生长空间三个变量作为函数自变量。