Competitive interactions of whiteleaf manzanita, herbs, Douglas-fir, and ponderosa pine in southwest Oregon

Whiteleaf manzanita (Arctostaphylosviscida Parry) was established on three sites at densities ranging from 0 to 27 000 seedlings/ha in 2-year-old mixed stands of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and ponderosa pine (Pinusponderosa Dougl. ex Laws.). Invading herbs were controlled by spraying all plots, except one at each site at the 13 500 manzanita/ha density level. Intraspecific manzanita competition reduced individual shrub basal diameter, leaf area, biomass, and canopy volume by the 3rd year of our study. In contrast, these variables increased at the highest density in the manzanita stand. Stem volume of 5-year-old conifers was reduced in relation to manzanita density, biomass, leaf area index, and canopy cover. The presence of herbaceous vegetation reduced both manzanita and conifer growth by the 3rd year.

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Response of Dry Edible Bean (Phaseolus vulgaris) Cultivars to Four Herbicides

Weed Technology ◽

10.1017/s0890037x00040355 ◽

1996 ◽

Vol 10 (3) ◽

pp. 512-518 ◽

Cited By ~ 40

Author(s):

Carl P. Urwin ◽

Robert G. Wilson ◽

Dave A. Mortensen

Keyword(s):

Leaf Area Index ◽

Leaf Area ◽

Seed Yield ◽

Herbicide Tolerance ◽

Canopy Cover ◽

Area Index ◽

Crop Tolerance ◽

Crop Injury ◽

Canopy Volume ◽

Dry Edible Bean

Dry edible bean tolerance to PPI-applied EPTC, alachlor and POST-applied imazethapyr was evaluated over two years at Scottsbluff, NE. Eight market classes of dry edible beans comprising 12 cultivars were studied. Crop tolerance was assessed by measuring crop injury, stand, leaf area index, leaf chlorosis, plant canopy volume, projected canopy cover, crop maturity, and seed yield. Leaf area index measured late in the growing season provided the best correlation with seed yield in both years. In 1993 and 1994, imazethapyr treatment caused crop injury, which resulted in a decrease of leaf area and in 1994 decreased seed yield. Differences in herbicide tolerance existed between market classes and cultivars, although the level of herbicide tolerance varied between years.

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Automated computation of leaf area index from fruit trees using improved image processing algorithms applied to canopy cover digital photograpies

Computers and Electronics in Agriculture ◽

10.1016/j.compag.2016.02.011 ◽

2016 ◽

Vol 123 ◽

pp. 195-202 ◽

Cited By ~ 24

Author(s):

Marco Mora ◽

Felipe Avila ◽

Marcos Carrasco-Benavides ◽

Gonzalo Maldonado ◽

Jeissy Olguín-Cáceres ◽

...

Keyword(s):

Image Processing ◽

Leaf Area Index ◽

Leaf Area ◽

Canopy Cover ◽

Fruit Trees ◽

Area Index ◽

Image Processing Algorithms ◽

Processing Algorithms

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Comparison of Methods of Estimating Leaf-Area Index In Old-Growth Douglas-Fir

Ecology ◽

10.2307/1939820 ◽

1986 ◽

Vol 67 (4) ◽

pp. 975-979 ◽

Cited By ~ 106

Author(s):

J. D. Marshall ◽

R. H. Waring

Keyword(s):

Leaf Area Index ◽

Leaf Area ◽

Douglas Fir ◽

Comparison Of Methods ◽

Old Growth ◽

Area Index

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Response of aboveground biomass increment, growth efficiency, and foliar nutrients to thinning, fertilization, and pruning in young Douglas-fir plantations in the central Oregon Cascades

Canadian Journal of Forest Research ◽

10.1139/x92-170 ◽

1992 ◽

Vol 22 (9) ◽

pp. 1278-1289 ◽

Cited By ~ 37

Author(s):

Alejandro Velazquez-Martinez ◽

David A. Perry ◽

Tom E. Bell

Keyword(s):

Leaf Area ◽

Aboveground Biomass ◽

Cultural Practices ◽

Growth Efficiency ◽

Douglas Fir ◽

Nitrogen And Phosphorus ◽

Area Index ◽

Biomass Increment ◽

Oregon Cascades

The effect of thinning and cultural practices (multinutrient fertilization, pruning) on total aboveground biomass increment and growth efficiency was studied over three consecutive 2-year periods (1981–1987) in young Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) plantations. Net aboveground biomass increment over the 6-year period averaged 14.5, 7.8, and 5.5 Mg•ha−1•year−1 for the high-, medium-, and low-density plots, respectively. Growth efficiency, after dropping sharply between leaf area indexes of 1 and 6 m2/m2, remained relatively constant up to a leaf area index of 17, the highest measured. Consequently, aboveground biomass increment continued to increase at leaf area indexes well above that at which the Beer–Lambert law predicts maximum light should be absorbed. Foliage analyses indicate that thinning improved nitrogen, potassium, and magnesium nutrition and increased the translocation of potassium from 1-year-old foliage to support new growth. However, fertilization increased foliar nitrogen and phosphorus contents only when coupled with pruning, suggesting that trees favor total leaf area over individual needle nutrition. Indications of potassium and magnesium limitations in this study are supported by other recent studies in Douglas-fir. Further work on the role of multinutrient deficiencies in this species is warranted.

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Root Volume and Growth of Ponderosa Pine and Douglas-Fir Seedlings: A Summary of Eight Growing Seasons

Western Journal of Applied Forestry ◽

10.1093/wjaf/12.3.69 ◽

1997 ◽

Vol 12 (3) ◽

pp. 69-73 ◽

Cited By ~ 19

Author(s):

R. Rose ◽

D. L. Haase ◽

F. Kroiher ◽

T. Sabin

Keyword(s):

Pinus Ponderosa ◽

Ponderosa Pine ◽

Douglas Fir ◽

Stem Volume ◽

Coast Range ◽

Root Volume ◽

Growth And Survival ◽

Growing Seasons ◽

Early Results

Abstract This is the final summary of two studies on the relationship between root volume and seedling growth; early results were published previously. Survival, growth, and stem volume were determined for 2+0 ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii) seedlings after 8 growing seasons. For each species, seedlings from three seedlots were assigned to one of three root-volume categories [<4.5 cm3 (RV1), 4.5-7 cm3 (RV2), and >7 cm3 (RV3) for ponderosa pine; <9 cm3 (RV1), 9-13 cm3 (RV2), and >13 cm3 (RV3) for Douglas-fir]. On a dry harsh ponderosa pine site on the eastern slopes of Mt. Hood in Oregon, where gopher and cattle damage decreased the number of seedlings, more seedlings in the highest root-volume category survived (70%) than in the smaller root-volume categories (62% and 50%). Douglas-fir on a good site in the Coast Range of Oregon showed significantly greater height and stem volume for the largest root-volume category, whereas annual shoot growth and survival did not differ. Root volume is one of several potentially useful criteria for predicting long-term growth and survival after outplanting. West. J. Appl. For. 12(3):69-73.

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Correlating Leaf Area Index of Ponderosa Pine with Hyperspectral CASI Data

Canadian Journal of Remote Sensing ◽

10.1080/07038992.1992.10855332 ◽

1992 ◽

Vol 18 (4) ◽

pp. 275-282 ◽

Cited By ~ 42

Author(s):

Peng Gong ◽

Ruiliang Pu ◽

John R. Miller

Keyword(s):

Leaf Area Index ◽

Leaf Area ◽

Ponderosa Pine ◽

Area Index

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Pasture damage and regrowth from cattle treading

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2000.62.2366 ◽

2000 ◽

pp. 155-160 ◽

Cited By ~ 4

Author(s):

T.N. Pande ◽

I. Valentine ◽

K. Betteridge ◽

A. Mackay ◽

D. Horne

Keyword(s):

Growth Rate ◽

Leaf Area Index ◽

Leaf Area ◽

Canopy Cover ◽

Control Treatment ◽

Research Station ◽

Area Index ◽

Hill Country ◽

Grazed Pasture ◽

Tiller Density

Two experiments were conducted to describe the damage and regrowth of pasture after a single, severe cattle treading event during winter. One experiment was conducted on hill country at AgResearch's Ballantrae Hill Country Research Station, and the other on the No. 4 Dairy Unit at Massey University. Herbage growth rate, canopy cover, tiller density and leaf area index were studied and compared in grazed, cattle-trodden and untrodden (control) pastures. At Ballantrae, the control treatment was sheep-grazed pasture, and at Massey University, it was cattle-grazed, but untrodden pasture under the electric fence. A single cattle treading event on winter-wet soils reduced hill pasture growth rates in spring to 11 kg DM/ha/day compared to 18 kg DM/ha/day in undamaged pasture on slopes, and to 21 kg DM/ ha/day compared to 39 kg DM/ha/day on tracks. Spring dairy pasture growth rate to 7 weeks after treading was 33 kg DM/ha/day compared to 51 kg DM/ha/day in undamaged pasture. Damage reduced canopy cover to 60% on hill pasture tracks and to 43% in dairy pasture, compared to covers of 95% and 90% in undamaged pastures, respectively. It was concluded that the low spring herbage growth rate following a single, severe winter treading of pasture on wet soil was due mainly to significantly reduced tiller numbers, and a decrease in leaf area index and canopy cover. Treading had no significant effect on the size of individual tillers. Keywords: cattle treading, hill country, pasture, pugging

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Shifts in Foliage Biomass and Its Vertical Distribution in Response to Operational Nitrogen Fertilization of Douglas-Fir in Western Oregon

Forests ◽

10.3390/f11050511 ◽

2020 ◽

Vol 11 (5) ◽

pp. 511 ◽

Cited By ~ 1

Author(s):

Jacob D. Putney ◽

Douglas A. Maguire

Keyword(s):

Vertical Distribution ◽

Nitrogen Fertilization ◽

N Fertilization ◽

Douglas Fir ◽

Tree Level ◽

Stem Volume ◽

Parameter Estimates ◽

Growth Responses ◽

Basal Diameter ◽

Dormant Season

Nitrogen (N) fertilization is a commonly applied silvicultural treatment in intensively managed coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) plantations. Field trials were established in a randomized complete block design by Stimson Lumber Company (Gaston, Oregon), to test the economic viability of N fertilization on their ownership and to better understand Douglas-fir growth responses. The 23 stands comprising the trials were Douglas-fir dominated, had a total age of 16–24 years, had been precommercially thinned, and had a density of 386–1021 trees ha−1. Fertilizer was applied aerially at a rate of 224 kg N ha−1 as urea during the 2009–2010 dormant season. In the dormant season of 2016–2017, seven growing seasons following application, 40 trees were felled and measured with the objective of assessing crown attributes and aboveground allometrics. Branch-level foliage mass equations were developed from 267 subsampled branches and were applied to the 40 felled sample trees on which the basal diameter and height of all live branches were measured, allowing estimation of both the total amount of foliage and its vertical distribution. A right-truncated Weibull distribution was fitted to data, with the truncation point specified as the base of live tree crown. The resulting tree-level parameter estimates were modeled as functions of tree-level variables. Stand-level factors not explicitly measured were captured through the use of linear and nonlinear mixed-effects models with random stand effects. Fertilization resulted in more total crown foliage mass in the middle crown-third and caused a downward shift in the vertical distribution of foliage, with implications for feedback responses in crown development and photosynthetic capacity. Defining the morphological responses of Douglas-fir crowns to nitrogen fertilization provides a framework for studying influences on stand dynamics and should ultimately facilitate improved site-specific predictions of stem-volume growth.

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