. Ponderosa pine saplings respond to control of spacing and understory vegetation. Ponderosa pine; Ponderosa pine Spacing. at progressively wider spacings. For example, during the first period, where understory vegetation .was removed and 1,000 trees per acre left, trees grew an average of foot per year compared with foot where only 62 trees were left. In the second period, however, trees at the widest spacing averaged feet per year. Understory vegetation reduced height growth on all spacings during both periods except during the first period where trees were spaced feet. Growt
. Ponderosa pine saplings respond to control of spacing and understory vegetation. Ponderosa pine; Ponderosa pine Spacing. at progressively wider spacings. For example, during the first period, where understory vegetation .was removed and 1,000 trees per acre left, trees grew an average of foot per year compared with foot where only 62 trees were left. In the second period, however, trees at the widest spacing averaged feet per year. Understory vegetation reduced height growth on all spacings during both periods except during the first period where trees were spaced feet. Growth reductions from understory vegetation were more severe as spacing increased. A maximum reduction in height growth of 42 percent occurred in the second period at the widest spacing. Height growth of individual trees ranged from an unmeasurable amount for some trees at the spacing to almost feet per year for one tree at the widest spacing. During the first period growth at the widest spacing was erratic, with some trees growing a foot or more in a year and others much less. During the second period, however, variation was greatly reduced at the wide spacings because all trees tended to grow uniformly well. Evidently there is a time lag, closely related to tree density, before trees are able to respond fully to their new spacing 1,000 500 250 125 62 TREES PER ACRE AND SPACING (FEET) Figure annual height growth during the first and second 4-year growth periods. 7. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Barrett, James W. (James Willis), 1922-. Portland, Or. : Pacific Northwest Forest and Range Experiment Station, U. S. Dept. of Agriculture
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Keywords: ., bookcentury1900, bookcollectionbiodive, booksubjectponderosapine
