Seedlings from two lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) provenances were planted at four square espacements of 1.8, 2.4, 3.0, and 3.7 m in the Sub-Boreal Spruce Zone of central British Columbia. Data for the first 20 years after planting were analyzed in terms of the entire stand and portions of it. Plantation espacement had a major effect on early growth and development. Wide spacings resulted in greater diameter increments and produced trees of larger bole and crown dimensions. Close spacings resulted in larger per-hectare stand values and smaller branch diameters.
The effects of spacing 7-year-old second-growth lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) are reported 20 growing seasons after treatment. Five spacing levels of 500, 1,000, 1,500, 2,000, and 2,500 trees per hectare, plus unspaced controls, were established on plots in central British Columbia. Both individual-tree and per-hectare data were analyzed. Spacing had a significant effect on all of the individual-tree characteristics examined, but its effect on per-hectare values was mixed. Although this report only provides short-term information on the effects of juvenile spacing on the growth and yield of lodgepole pine, it does indicate the need to optimize individual-tree growth rates with levels of growing stock to maximize yield per unit area. West. J. Appl. For. 20(3):160–166.
Hybrid poplar (Populus trichocarpa Torr. and Gray × Populus deltoides Marsh.) plantations, at two locations in southern British Columbia, were examined 9 years after planting, to determine the effects of plantation spacing on individual-tree and per-hectare growth and development. At both locations, spacing had a direct, significant effect on virtually all of the individual-tree characteristics examined. For a given amount of growing space per tree, rectangularity (within-row/between-row spacing ratios) had no significant effect on individual-tree diameter, height, or total bole volume. Virtually all of the per-hectare characteristics examined were not significantly affected by spacing at either location.
Spacing and provenance effects on the performance of shore pine (Pinuscontorta var. contorta) at a frost-prone site in coastal British Columbia were investigated with respect to mortality, growth, stem defects, and disease and insect damages in a trial with six seed sources that were assigned to seven spacing regimes from 749 to 2990 stems per hectare. Twenty-year test results indicate that mortality was low (2.3% on average) and not significantly influenced by spacing. However, spacing effects on the other traits were significant. Increasing planting density reduced the proportion of stem defected and disease- and insect-damaged trees, slowed diameter and stem volume growth of individuals, and stimulated height growth. Height growth responded to planting density earlier than diameter growth, but diameter growth became more affected as trees grew. The total volume per hectare increases with planting density, but the rate of increase declined as the test proceeded. Response to planting density was homogeneous among provenances with respect to all the traits investigated. However, large and significant regional and provenance differences in mortality, growth, and disease and insect susceptibility were detected. Northern and outer coast provenances demonstrated higher mortality, slower growth, and larger proportions of disease- and insect-damaged trees. Clearly, determining appropriate spacing levels and selecting suitable seed sources are both important for the success of reforestation with shore pine at difficult sites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.