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[1] [2] When taking forest inventory the following are important things to measure and note: species, diameter at breast height (DBH), height, site quality, age, and defects. From the data collected one can calculate the number of trees per acre, the basal area, the volume of trees in an area, and the value of the timber. Inventories can be ...
Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements. Electronic calipers can measure diameter at breast height and send measured data via Bluetooth to a field computer .
Photographs of trees can be used to determine girth or other measurements if there is a something of known size in the photo to provide a scale. The following information must be known to approximate the measurements: 1) distance of the camera from the tree, 2) distance from the camera to the scale, and 3) size of the object to be used as a scale.
Until this stage, the seedling lives off the energy reserves stored in the seed. The opening of the cotyledons exposes the shoot apical meristem and the plumule consisting of the first true leaves of the young plant. The seedlings sense light through the light receptors phytochrome (red and far-red light) and cryptochrome (blue light).
Etiolation of the seedling causes it to become elongated, which may facilitate it emerging from the soil. A seedling that emerges in darkness follows a developmental program known as skotomorphogenesis (dark development), which is characterized by etiolation. Upon exposure to light, the seedling switches rapidly to photomorphogenesis (light ...
Prochnau (1963), [129] four years after sowing, found that 14% of viable white spruce seed sown on mineral soil had produced surviving seedlings, at a seed:seedling ratio of 7.1:1. With Engelmann spruce, Smith and Clark (1960) [ 130 ] obtained average seventh year seed:seedling ratios of 21:1 on scarified seedbeds on dry sites, 38:1 on moist ...
Seedling shoot height, root collar diameter, and dry weight increased at a greater rate in seedlings than in emblings during the first half of the first growing season, but thereafter shoot growth was similar among all plants. By the end of the growing season, seedlings were 70% taller than emblings, had greater root collar diameter, and ...
Fruits. Gmelina arborea grows naturally throughout India, Myanmar, Thailand, Laos, Cambodia, Vietnam and in southern provinces of China. It is found at altitudes from sea level to 1,500 metres (5,000 ft). [1]