Effect of management activities on forest soil properties in the Rocky Mountains: I. Understory vegetation

This data set contains vegetation measurements collected in a study that was designed to determine how mechanical site preparation and prescribed fire affected understory vegetation growth, conifer establishment and growth, and soil physical and chemical properties of some Rocky Mountain national forests. The treatments (listed by treatment code) applied to the sites included the following: 1 = bole removed followed by broadcast burn, 2 = bole removed followed by dozer or grapple pile, 3 = control (undispersed), 4 = whole tree removal (only in 1990 Helena/Deerlodge Forest), and 9 = burned only. Not every treatment was used in each forest.

The data in this publication were collected over a five-year period (1989-1993) from 11 national forests located in Montana, Idaho, and Arizona. The data focus on the recovery of understory vegetation after treatment. It consists of information on habitat types (Pfister et al. 1977) at each sample location, estimates of cover for all species present at the sample location, and estimates of height for each species present.

The original intent of the study was to summarize the data to an individual stand so returning to each stand for additional sampling in subsequent years was not planned and plot locations were not permanently marked. However, written or diagrammed descriptions of the location of each sample site exist on the sample forms. These descriptions are included with these archived data in case there is a future need to return to the sample areas.The overall purpose of this study was to determine how management practices, such as burning, machine piling, scarifying, and scalping, change the character of the organic-rich surface soil layer; and how this change affects seed sprouting, seed-growth performance, and mycorrhizal development that maintains vegetation in these Rocky Mountain forests.

The specific purpose of the understory vegetation research was to determine if vegetation composition changed depending on whether the site was dozer piled or prescribe burned compared to an adjacent unharvested area and whether soil chemistry changes caused by the treatments may have affected seed germination and seed spread throughout the stand.There are six separate data publications containing the data collected to examine the effect of management activities on forest soil properties in the Rocky Mountains: I. understory vegetation; II. tree, stump, and downed woody debris data (variable plots and transects); III. soil core data; IV. soil chemistry data; V. burn and soil surface conditions; and VI. microsite data.

Data were originally published on 08/04/2021. Minor metadata updates were made on 09/24/2021.

本数据集收录了在旨在探究机械场地准备和预定火灾如何影响林下植被生长、针叶植物建立与生长，以及某些落基山脉国家森林土壤的物理和化学性质的研究中收集的植被测量数据。所应用的处置方法（按处置代码列出）包括以下几种：1 = 切除树干后进行广播燃烧，2 = 切除树干后使用推土机或抓斗堆叠，3 = 对照组（未分散），4 = 全树去除（仅限于1990年海伦娜/迪尔洛奇森林），以及9 = 仅燃烧。并非每个处置方法在每座森林中都有应用。

本出版物中的数据收集于1989年至1993年间的五年期间，来自蒙大拿州、爱达荷州和亚利桑那州的11个国家森林。数据聚焦于处置后的林下植被恢复情况。它包括每个采样位置的生境类型（Pfister et al. 1977）、所有在采样位置出现的物种的覆盖度估算，以及每个在采样位置出现的物种的高度估算。

研究之初的宗旨是对数据进行汇总，以个体林分为单位，因此并未计划在后续年份返回每个林分进行额外采样，且样地位置并未永久标记。然而，样本表格上存在关于每个采样位置位置的书面或图表描述。这些描述随存档数据一同提供，以防未来有返回采样区域的需求。本研究的总体目的是探究管理实践，如燃烧、机械堆叠、划痕和削皮，如何改变富含有机质的表层土壤层的特性；以及这种变化如何影响种子萌发、种子生长性能以及维持这些落基山脉森林植被的菌根发育。

林下植被研究的具体目的是确定植被组成是否因样地是推土机堆叠还是预定燃烧，与相邻的非采伐区相比而发生变化，以及由处置引起的土壤化学变化是否可能影响种子发芽和种子在整个林分中的扩散。共有六个独立的数据出版物包含收集的数据，以检验管理活动对落基山脉森林土壤特性的影响：I. 林下植被；II. 树木、树桩和倒木数据（变量样地和样带）；III. 土壤柱数据；IV. 土壤化学数据；V. 燃烧和土壤表面条件；VI. 微生境数据。

原始数据于2021年8月4日发布。在2021年9月24日进行了少量元数据更新。