Precommercial thinning of trembling aspen in northern Ontario: Part 2 – Interactions with Hypoxylon canker

2001 ◽  
Vol 77 (5) ◽  
pp. 902-910 ◽  
Author(s):  
Doug Pitt ◽  
David Weingartner ◽  
Sylvia Greifenhagen
Keyword(s):  
Populus Tremuloides ◽  
Planning Process ◽  
Block Design ◽  
Growth And Yield ◽  
Trembling Aspen ◽  
Northern Ontario ◽  
Precommercial Thinning ◽  
Crop Planning ◽  
Incidence And Mortality ◽  
Canopy Position

Hypoxylon canker [Entoleuca mammata (Wahlenberg:Fr) J.D. Rogers and Y.-M. Ju] incidence and mortality were monitored in six northern Ontario trembling aspen (Populus tremuloides Michx.) stands following precommercial thinning. At each of the six sites, a randomized complete block design experiment was established with four replicates of five thinning levels (none, 2-, 3-, 4-, and 5-m spacing). At the time of thinning, three stands were five years old; the remaining were ages 10, 15, and 22. Over the 15- to 17-year observation period, Hypoxylon-related mortality increased to 6–9% by the end of the period, regardless of thinning age or density. Hypoxylon infection incidence (excluding mortality) also increased, to 2–6% in unthinned stands and 8–11% in thinned stands by year 15. No differences among the thinning levels were observed. Prevalence, infection expressed as a percentage of surviving trees, did not differ among thinned and unthinned stands. Mortality attributed to factors other than Hypoxylon was 31–44% in unthinned stands and 7–23% in thinned stands, with no significant differences among thinning levels. Trees dying of other causes were typically small in diameter and of more subordinate crown classes than survivors. In contrast, Hypoxylon-caused mortality was independent of tree size and canopy position. Results suggest that log size and stand yield may be manipulated through density regulation, without concern for interacting impacts associated with Hypoxylon canker. Models are provided for estimating disease losses; predictions can then be factored into the crop-planning process. Key words: trembling aspen, precommercial thinning, Hypoxylon canker, growth and yield, crop planning

Precommercial thinning of trembling aspen in northern Ontario: Part 1 – Growth responses

2001 ◽  
Vol 77 (5) ◽  
pp. 893-901 ◽  
Author(s):  
James A. Rice ◽  
G. Blake MacDonald ◽  
David H. Weingartner
Keyword(s):  
Populus Tremuloides ◽  
Trembling Aspen ◽  
Growth Responses ◽  
Northern Ontario ◽  
Individual Tree ◽  
Precommercial Thinning ◽  
Individual Tree Growth ◽  
Aspen Tree ◽  
Fibre Yield ◽  
Residual Tree

In Ontario, trembling aspen (Populus tremuloides Michx.) utilization has increased over the past 20 years and this trend is expected to continue. With this increased demand, questions are being raised about stand conditions required for optimum growth. In 1979, a study was initiated across the commercial range of aspen in northern Ontario to determine the optimum precommercial thinning intensities for aspen tree and stand growth. Six pure aspen stands between the ages of five and 22 years were thinned to residual spacings of 2 × 2 m, 3 × 3 m, 4 × 4 m, and 5 × 5 m. Unthinned and thinned plots were measured at regular intervals for up to 17 years after treatment. Diameter increased significantly with residual tree spacing over the range of site conditions, geographic locations, and tree ages. Precommercial thinning resulted in significantly increased height in three of the stands, and height generally increased with increased residual spacing. Fifteen to 17 years after treatment, gross total volume (GTV) was highest in the unthinned plots for all six stands and decreased as residual tree spacing increased. Gross merchantable volume (GMV) did not vary significantly with thinning in all but the oldest stand. The results of this study do not support the use of precommercial thinning to increase aspen fibre yield. However, if the management goal is maximizing individual tree growth, precommercial thinning of aspen should be considered. Key words: Trembling aspen, precommercial thinning, DBH response, height response, northern Ontario

Long-term outcome of precommercial thinning in northwestern New Brunswick: growth and yield of balsam fir and red spruce

2008 ◽  
Vol 38 (3) ◽  
pp. 592-610 ◽  
Author(s):  
Doug Pitt ◽  
Len Lanteigne
Keyword(s):  
Block Design ◽  
Abies Balsamea ◽  
Red Spruce ◽  
Balsam Fir ◽  
Growth And Yield ◽  
Stem Volume ◽  
Long Term Outcome ◽  
Precommercial Thinning ◽  
Minimum Requirement

A study was established between 1959 and 1961 to study the long-term responses of balsam fir ( Abies balsamea (L.) Mill.) and red spruce ( Picea rubens Sarg.) to precommercial thinning. Three nominal spacings of 4 ft (1.2 m), 6 ft (1.8 m), and 8 ft (2.4 m) were compared with an unthinned control in a randomized complete block design with five replicates. At the time of thinning, natural regeneration averaged 16 years of age, 8 years after harvest. Although thinning had minimal effect on gross total volume production over a 42 to 44 year observation period, actual spacings between 2.1 and 2.5 m produced an average of 360 m3·ha–1gross merchantable volume (GMV), representing a 21% gain over unthinned stands. The same spacings produced quadratic mean diameters of 21 and 23 cm, respectively, compared with 18 cm in the unthinned stands. These size increases translated to individual stem volume gains of 33% and 62%, significantly reducing the age at which thinned stands would meet a specified minimum requirement for merchantability or habitat. The mean annual increment of GMV ranged from 6 m3·ha–1·year–1in unthinned stands, to more than 7 m3·ha·–1·year–1in the thinned stands, and had not yet culminated an average of 50 years postharvest.

scholarly journals Spatial and temporal patterns of Populus tremuloides regeneration in small forest openings in northern Ontario

2009 ◽  
Vol 85 (4) ◽  
pp. 548-557 ◽  
Author(s):  
Arthur Groot ◽  
Rongzhou Man ◽  
Jim Wood
Keyword(s):  
Populus Tremuloides ◽  
Tree Height ◽  
Forest Harvesting ◽  
Trembling Aspen ◽  
Spatial And Temporal Patterns ◽  
Northern Ontario ◽  
Mixedwood Forests ◽  
Boreal Mixedwoods ◽  
Silvicultural System ◽  
Forest Openings

The density, height and diameter of trembling aspen sucker regeneration was assessed over a 10-year period in openings created by harvesting in a 40-year-old, 19-m-tall aspen stand in northeastern Ontario. The 5 types of opening comprised: circular openings of 9-m- and 18-m-diameter, 150-m-long east–west strips of 9-m and 18-m width, and a 1.5 ha (100 m × 150 m) clearcut. Density of aspen regeneration was significantly affected by opening type, location relative to the opening, time since harvest, and by all interactions of these factors. Aspen densities within the circular openings declined to low levels by year 10, despite considerable initial recruitment. Trembling aspen height and diameter were significantly influenced by opening type, location relative to the opening, time since harvest, and by opening × time and location × time interactions. Trembling aspen heights in the circular openings were substantially less than in the clearcut and strip openings by year 10. The results support the traditional view that aspen is best managed under the clearcut silvicultural system, and that trembling aspen regeneration following forest harvesting can be reduced by controlling the extent or intensity of overstory removal. Finally, the results suggest that disturbances that create gaps greater than 1 tree height in width in aspen or mixedwood forests may allow gap dynamics to function. Key words: trembling aspen, silviculture, boreal mixedwoods, regeneration, forest openings

scholarly journals Widespread mortality of trembling aspen (Populus tremuloides) throughout interior Alaskan boreal forests resulting from a novel canker disease

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250078
Author(s):  
Roger W. Ruess ◽  
Loretta M. Winton ◽  
Gerard C. Adams
Keyword(s):  
Populus Tremuloides ◽  
Fungal Pathogens ◽  
Stand Structure ◽  
The United States ◽  
Leaf Miner ◽  
Summer Drought ◽  
Trembling Aspen ◽  
Interior Alaska ◽  
Incidence And Mortality ◽  
Paper Birch

Over the past several decades, growth declines and mortality of trembling aspen throughout western Canada and the United States have been linked to drought, often interacting with outbreaks of insects and fungal pathogens, resulting in a “sudden aspen decline” throughout much of aspen’s range. In 2015, we noticed an aggressive fungal canker causing widespread mortality of aspen throughout interior Alaska and initiated a study to quantify potential drivers for the incidence, virulence, and distribution of the disease. Stand-level infection rates among 88 study sites distributed across 6 Alaska ecoregions ranged from <1 to 69%, with the proportion of trees with canker that were dead averaging 70% across all sites. The disease is most prevalent north of the Alaska Range within the Tanana Kuskokwim ecoregion. Modeling canker probability as a function of ecoregion, stand structure, landscape position, and climate revealed that smaller-diameter trees in older stands with greater aspen basal area have the highest canker incidence and mortality, while younger trees in younger stands appear virtually immune to the disease. Sites with higher summer vapor pressure deficits had significantly higher levels of canker infection and mortality. We believe the combined effects of this novel fungal canker pathogen, drought, and the persistent aspen leaf miner outbreak are triggering feedbacks between carbon starvation and hydraulic failure that are ultimately driving widespread mortality. Warmer early-season temperatures and prolonged late summer drought are leading to larger and more severe wildfires throughout interior Alaska that are favoring a shift from black spruce to forests dominated by Alaska paper birch and aspen. Widespread aspen mortality fostered by this rapidly spreading pathogen has significant implications for successional dynamics, ecosystem function, and feedbacks to disturbance regimes, particularly on sites too dry for Alaska paper birch.

Building a dynamic growth model for trembling aspen in western Canada without age data

2013 ◽  
Vol 43 (3) ◽  
pp. 256-265 ◽  
Author(s):  
Oscar García
Keyword(s):  
Populus Tremuloides ◽  
Site Occupancy ◽  
Basal Area ◽  
Site Index ◽  
Growth And Yield ◽  
Site Quality ◽  
Diameter Distribution ◽  
Stand Age ◽  
Parameter Estimates ◽  
Trembling Aspen

A biologically inspired whole-stand growth and yield model was developed for even-aged thinned or unthinned stands dominated by trembling aspen (Populus tremuloides Michx.). The estimation used permanent sample plot data from British Columbia, Alberta, Saskatchewan, and Manitoba, supplemented by published site index and young stand information. An ingrowth imputation procedure was devised to facilitate the use of plot measurements where small trees are not measured. Two published site index models were closely approximated by a simple age-base invariant equation. Good parameter estimates for mortality and basal area growth were obtained without using age observations, which were unreliable or missing. Four differential equations describe the dynamics of top height, trees per hectare, basal area, and a site occupancy factor. Current values of these variables are used to estimate total and merchantable volumes up to any diameter limit and diameter distribution parameters. When an independent source of site quality estimates is available, the final model does not require stand age knowledge for making growth and yield predictions.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

Effect of Urea and Nano-Nitrogen Fertigation and Foliar Application of Nano-Boron and Molybdenum on some Growth and Yield Parameters of Potato

2020 ◽  
Vol 10 (1) ◽  
pp. 253-263
Author(s):  
Hayyawi W.A. Al-juthery ◽  
Estabraq Hilal Obaid Al-Maamouri
Keyword(s):  
Foliar Application ◽  
Growth Traits ◽  
Solanum Tuberosum L ◽  
Block Design ◽  
Growth And Yield ◽  
Control Treatment ◽  
Acid Yield ◽  
Biological Yield ◽  
Starch Yield ◽  
Private Farm

Investigating the effect of urea and nano-nitrogen fertigation and foliar application of nano B and Mo on growth and yield of potato Solanum tuberosum L. [Rivera-A]. The study was conducted in a private farm located in the Al-Taleah area - Babylon governorate. The experiment consisted of (12) treatments consisting of separated fertigation of nano nitrogen (25% N) and urea (46% N), single treatments of leaf spraying of nano Mo (5%), Nano B (9%), nano-binary combinations (Mo+B) and (U+ Nano Mo), (U+Nano B), Nano (N+Mo), Nano (N+B), and tricombination treatments of (U+Mo+B), Nano (N+Mo+B) additional to the control treatment. Randomize Complete Block Design (RCBD) and one way simple experiment with three replicates. Fertilizers were applied at levels of 40 liters h-1 of Nano-N fertilizer (25% N) and 300 kg h-1 urea fertilizer (46% N). They were sprayed early in the morning after (40) days after planting four times. Two weeks is the period between an application and another according to the recommendation of (1) kg  h-1 nano-fertilizer of (B) and (500) g h-1 of  Mo. Fertilizers were injected and sprayed at (10, 20, 30 and 40)% of the total amount of the fertilizer were applied as the first, second, third and fourth applications, respectively. Some growth traits were tested including the chlorophyll content in the leaves, the total dry vegetative yild, the soft tubers yield, and the biological yield, proteins and ascorbic acid yield compared to the control (spray water only). The results of the Duncan test showed a significant increase in most of the studied traits of nano-tricombination (N+Mo+B) in the fresh tubers yield,  dry vegetative yield  , the biological yield, starch yield ,the total protein and ascorbic yield (37.53, 1.799, 8.138,4.152 , 481.3and 653.8 meg ha-1) respectively .compare to control (21.58 , 0.890, 4.463  ,2.323 , 366.1 and 215.5 meg ha-1) respectively.

EFFECT OF DIFFERENT DOSES OF BORON ON GROWTH AND YIELD OF OFF-SEASON CAULIFLOWER (BRASSICA OLERACEA VAR. BOTRYTIS) IN ARGHAKHANCHI, NEPAL

2020 ◽  
Vol 1 (1) ◽  
pp. 12-17
Author(s):  
Srijana Pandey ◽  
Sapana Parajuli ◽  
Biplov Oli ◽  
Surya Dhungana
Keyword(s):  
Brassica Oleracea ◽  
Growth Parameters ◽  
Block Design ◽  
Leaf Length ◽  
Growth And Yield ◽  
Cost Ratio ◽  
Benefit Cost Ratio ◽  
Net Returns ◽  
Benefit Cost ◽  
Different Doses

The research was conducted at Beltari Sandhikharka-10, Arghakhanchi district to study about the effect of various doses of boron on growth and yield attributing characters of cauliflower (Brassica oleracea var. botrytis) during off-season from February to June in 2020. Five treatments; B0 (control/no application), B1: 2kg/ha, B2: 4kg/ha, B3: 6kg/ha, B4: 8kg/ha which are the different doses of boron application were laid out in Randomized Complete Block Design (RCBD) with 4 replications. The growth parameters like plant height, number of leaves per plant leaf length and leaf breadth of largest leaf were recorded multiple times with 15 days interval. Days to curd initiation and Days from curd initiation to harvest were recorded by regular field observation. The yield parameters; curd weight with leaves, Marketable curd weight, average curd yield, incidence of hollowing were recorded during harvest. The economics from application of boron doses in cauliflower production was obtained in terms of cost of cultivation, gross returns, net returns, and benefit cost ratio. The result showed that the growth and yield attributing characters of cauliflower were significantly affected by application of boron in which the value of these parameters was found significantly higher in B1 followed by other treatments. The average curd yield of cauliflower in B1 was found to be 12.39 mt/ha which was 48.92% higher than that of B0 with curd yield 8.32 mt/ha. Similarly, the net return was found significantly the highest in B1 and the lowest in B0. The result showed that application of boron in the range of 2-4 kg/ha is preferred to control and higher doses in respect of both productivity and economics.

PENGARUH KOMPOS SAMPAH KOTA DAN PUPUK KANDANG SAPI TERHADAP PERTUMBUHAN DAN HASIL TANAMAN PAKCOY (BRASSICA RAPA, L. CHINENSIS) PADA ALUVIAL KABUPATEN INDRAMAYU

2018 ◽  
Vol 9 (2) ◽  
pp. 153-163
Author(s):  
Wiwik Ambarsari ◽  
Henly Yuliana
Keyword(s):  
Plant Height ◽  
Brassica Rapa ◽  
Block Design ◽  
Cattle Manure ◽  
Growth And Yield ◽  
Randomized Block Design ◽  
Two Factors ◽  
Number Of Leaves ◽  
Experimental Garden

The study aimed to determine the effect of the combination of city waste compost and cattle manure on the growth and yield of pakcoy plants (Brassica rapa, L. Chinensis) in Aluvial, Indramayu Regency. The study was conducted at the Experimental Garden of the Faculty of Agriculture, Wiralodra University, Indramayu Regency from March to August 2018. This study used Factorial Pattern Randomized Block Design with two factors. The first factor is city waste compost and the second factor is cattle manure with 4 levels: 0%, 3.0%, 6.0%, and 9.0%, repeated twice. The results showed that there was an independent influence between city waste compost and cattle manure on plant height and number of leaves. The best combination to increase the feasibility weight of pakcoy consumption is by giving city waste compost 9.0% (S4) and cattle manure 6.0% (K3).

Effectiveness of nitrogen and bio-fertilizer choice for improving growth and yield of hybrid rice (Oryza sativa L.) during dry season

2020 ◽  
Vol 57 (4) ◽  
pp. 302-309
Author(s):  
Sukanta Pal ◽  
Megha Sana ◽  
Hirak Banerjee ◽  
Lhingneikim Lhungdim
Keyword(s):  
Yield Components ◽  
Hybrid Rice ◽  
Growth Parameters ◽  
Oryza Sativa L ◽  
Block Design ◽  
Growth And Yield ◽  
Combined Application ◽  
Randomized Block Design ◽  
N Dose ◽  
Dry Seasons

Effect of nitrogen and bio-fertilizer on growth and productivity of hybrid rice (cv. PHB 71) was assessed during dry seasons of 2017 and 2018 at Research Farm of BCKV under new alluvial zone of West Bengal. The experiment was laid out in factorial randomized block design with 12 treatment combinations having 4 levels of N and 3 types of bio-fertilizer replicated thrice. Application at 180 kg N/ha produced tallest plants at 90 DAT with maximum LAI (60 DAT), DMA (90 DAT), tillers/hill (90 DAT) and CGR (30-60 & 60-90 DAT). The same N rate resulted in highest panicles/m2, panicle length, panicle weight, filled grains/panicle and 1000-grain weight. A decrease in N dose from 180 to 150 kg/ha caused reduction in all those yield components; however, the variation was non-significant except for number of panicles/m2. Maximum grain yield, straw yield and harvest index was also achieved with 180 kg N/ha accounting 120.1, 34.9 and 32.8% more than the values obtained with zero-N; however, it was statistically at par with the yields and HI obtained with 150 kg N/ha. The Azospirillum application increased all the growth parameters, yield components and yield of hybrid rice over other tested bio-fertilizers (Azospirillum > PSB > K mobilizer), accounting 5.9 and 8.8% more than the yields obtained with PSB and K mobilizer. The interaction of N and bio-fertilizer exerted significant effect on growth attributes but failed to record any significant variations in yield components and yield of hybrid rice. The maximum economic benefit was achieved with combined application of 180 kg N/ha and Azospirillum.

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