Biomass and growth of Populustremuloides in northeastern Alberta: estimates using hierarchy in tree size

1984 ◽  
Vol 14 (5) ◽  
pp. 610-616 ◽  
Author(s):  
V. J. Lleffers ◽  
J. S. Campbell
Keyword(s):  
Basal Area ◽  
Stand Density ◽  
Allometric Equation ◽  
Point Estimate ◽  
Low Density ◽  
Tree Biomass ◽  
Stand Growth ◽  
Single Tree ◽  
The Difference ◽  
Northeastern Alberta

Biomass and growth (productivity) of Populustremuloides Michx. was determined from 20 × 20 m plots in 39 even-aged stands in northeastern Alberta. The diameters of all trees were measured at a 1.3-m height. In each stand, the periodic annual basal area increment (1977–1981) of 10–16 sample trees was proportional to the square of the diameter of each tree. This relationship was used to estimate the change in diameter of each tree in the stand for the 5-year period. The current biomass and the biomass per tree 5 years earlier were determined from an allometric equation of tree biomass versus diameter. A point estimate of growth over the last 5 years was determined by the difference between these values. Stands ranged from 23 to 57 years old, aboveground biomass from 37 to 156 t ha−1, and current rates of production from 1.5 to 5.2 t ha−1 year−1. Single tree cumulative biomass and growth were highest in low density and older stands. Stand biomass was highest in older stands but showed no relationship to stand density. Stand growth was not related to age, but was higher in more dense stands. There was no detectable reduction in growth near an SO2 source in the study area.

scholarly journals Life at the margin: the mating system of Mediterranean conifers

Web Ecology ◽  
2008 ◽  
Vol 8 (1) ◽  
pp. 94-102 ◽  
Author(s):  
G. Restoux ◽  
D. E. Silva ◽  
F. Sagnard ◽  
F. Torre ◽  
E. Klein ◽  
...  
Keyword(s):  
Mating System ◽  
Stand Density ◽  
High Density ◽  
Published Data ◽  
Mixed Mating ◽  
Low Density ◽  
Selfing Rate ◽  
Water Regimes ◽  
Single Tree ◽  
Mature Stand

Abstract. Mixed mating, where a single tree progeny results from a mixture of selfing and outcrossing, is widespread in conifers and could be an evolutionary advantage at ecological margins when mating partners become scarce. This study analyzes how the mating system responds to bioclimate and density variations. We surveyed published data on the mating system of Abies, Picea and Pinus species when information on bioclimate and stand density was available. Our survey revealed that Mediterranean species demonstrate a lower selfing rate than other species and that the proportion of selfed versus outcrossed progeny is not fixed within species. The highest variability in mating types within populations was found when stand density was the most variable. To show how density affects the proportion of selfed versus outcrossed progeny, we used isozymes to genotype single tree seeds from a marginal Abies alba forest in Mediterranean France (Mont Ventoux) where low-to high-density stands are found. We then tested the adaptive potential of the different high and low density progenies by sowing them under controlled nursery conditions and measuring germination rate and seedling survival after 4 yr under 3 different water regimes. Although the mean value of outcrossing rate was typical for mixed mating conifers (tm = 0.85), individual outcrossing rates varied from 0.05 to 0.99 and were strongly correlated with stand type and density (tm from 0.87 in high-density to 0.43 in low-density marginal stands). Significantly fewer seeds from the low density marginal stand germinated (32% vs. 53% in the high density mature stand), although seedlings from the marginal stand had a better 4-yr survival (81%) than seedlings from the high-density mature stand (63%) when the three water regimes (from least to most stressful) were averaged. Trees from low density stands may be at a selective disadvantage because they produce more selfed progeny than trees from high-density stands. However, selfed seeds may be purged early on (at the embryo stage) and the remaining seeds tend to produce seedlings with better fitness. Variability of the selfing rate might thus be an adaptive strategy for species in highly contrasted environments where selection of both reproductive assurance and avoidance of inbreeding depression may be density dependent.

scholarly journals Temporal Transferability of Pine Forest Attributes Modeling Using Low-Density Airborne Laser Scanning Data

2019 ◽  
Vol 11 (3) ◽  
pp. 261 ◽  
Author(s):  
Darío Domingo ◽  
Rafael Alonso ◽  
María Teresa Lamelas ◽  
Antonio Luis Montealegre ◽  
Francisco Rodríguez ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Growth Models ◽  
Model Performance ◽  
Basal Area ◽  
Stand Density ◽  
Airborne Laser Scanning ◽  
Support Vector ◽  
Low Density ◽  
Airborne Laser ◽  
Forest Attributes

This study assesses model temporal transferability using airborne laser scanning (ALS) data acquired over two different dates. Seven forest attributes (i.e. stand density, basal area, squared mean diameter, dominant diameter, tree dominant height, timber volume, and total tree biomass) were estimated using an area-based approach in Mediterranean Aleppo pine forests. Low-density ALS data were acquired in 2011 and 2016 while 147 forest inventory plots were measured in 2013, 2014, and 2016. Single-tree growth models were used to generate concomitant field data for 2011 and 2016. A comparison of five selection techniques and five regression methods were performed to regress field observations against ALS metrics. The selection of the best regression models fitted for each stand attribute, and separately for both 2011 and 2016, was performed following an indirect approach. Model performance and temporal transferability were analyzed by extrapolating the best fitted models from 2011 to 2016 and inversely from 2016 to 2011 using the direct approach. Non-parametric support vector machine with radial kernel was the best regression method with average relative % root mean square error differences of 2.13% for 2011 models and 1.58% for 2016 ones.

scholarly journals A Local Basal Area Adjustment for Crown Width Prediction

2001 ◽  
Vol 18 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Don C. Bragg
Keyword(s):  
Shade Tolerance ◽  
Basal Area ◽  
Stand Density ◽  
Regression Equations ◽  
Ecological Significance ◽  
Area Effect ◽  
Crown Width ◽  
Lake States ◽  
The Difference

Abstract Nonlinear crown width regression equations were developed for 24 species common to the upper Lake States of Michigan, Minnesota, and Wisconsin. Of the species surveyed, 15 produced statistically significant (P < 0.05) local basal area effect coefficients showing a reduction in crown width with increasing stand density. No relation between shade tolerance and crown width was apparent, indicating the species-dependence of this parameter. Using adjusted R2 as a guide, nonlinear crown width models adapted for local basal area (NLCWadj) improved prediction for 20 of 24 species over a model lacking this component (NLCW). The ecological significance of the improvement shown for some species may be minor, but for others the difference was substantial (often 8%). North. J. Appl. For 18(1):22–28.

Estimating site productivity in irregular stand structures by indexing the basal area or volume increment of the dominant species

2014 ◽  
Vol 44 (1) ◽  
pp. 92-100 ◽  
Author(s):  
John-Pascal Berrill ◽  
Kevin L. O’Hara
Keyword(s):  
Basal Area ◽  
Stand Density ◽  
Site Productivity ◽  
Mixed Stands ◽  
Individual Tree ◽  
Coast Redwood ◽  
Stand Growth ◽  
Permanent Sample Plots ◽  
Partial Harvesting ◽  
Volume Increment

Estimating site productivity in irregular structures is complicated by variations in stand density, structure, composition in mixed stands, and suppression experienced by subordinate trees. Our objective was to develop an alternate to site index (SI) and demonstrate its application in models of individual-tree and stand growth. We analyzed coast redwood (Sequoia sempervirens (Lamb. ex D. Don) Endl.) tree and stand growth in a grid of 234 permanent sample plots covering a 110 ha study area in north coastal California. Partial harvesting created a mosaic of densities and openings throughout the 60-year-old redwood-dominated forest. Redwood SI was a poor predictor of volume increment (VI) per hectare among redwood in each plot over two decades after harvest. A new index of redwood basal area increment (BAI) productivity, calculated using inventory data for all stems in even-aged stands and the oldest cohort of multiaged stands, was a stronger predictor of VI. Diameter increment of individual redwood trees correlated strongly with stand density and the new BAI index. Forest managers should expect widely divergent responses following partial harvesting in crowded even-aged stands, with the greatest response coming from dominant redwoods with long crowns retained in areas with low residual stand density and high BAI index.

scholarly journals Simulating Multiaged Coast Redwood Stand Development: Interactions between Regeneration, Structure, and Productivity

2009 ◽  
Vol 24 (1) ◽  
pp. 24-32 ◽  
Author(s):  
John-Pascal Berrill ◽  
Kevin L. O'Hara
Keyword(s):  
Stand Structure ◽  
Basal Area ◽  
Stand Density ◽  
Site Index ◽  
Growth And Yield ◽  
Stand Development ◽  
Area Index ◽  
Coast Redwood ◽  
Stand Growth ◽  
Upper Limit

Abstract Multiaged management regimes and harvesting scenarios were simulated in coast redwood (Sequoia sempervirens [D. Don.] Endl.) stands using models of stand growth and yield (CRYPTOS) and stocking assessment (redwood MASAM). Various stocking and age-class combinations were modeled on site index 100 and 130 ft (50 years). Results demonstrated how the number of cohorts, upper limit of stocking, and cohort densities affected growth and yield. Board foot volume increment reached a plateau in stands with a prescribed upper limit of stocking above leaf area index 7.2 to 8.6. Productivity did not differ between stands with two to five cohorts producing the same tree size at harvest. It was affected by stand structure when a cutting cycle of 20 years was prescribed in stands with three to five cohorts. Stands with the same density returned to the upper limit of stocking much sooner on better sites. Prolonging the cutting cycle by reducing stand density resulted in larger tree sizes at harvest and greater productivity. The growth of trees remaining after cutting 10–50% of stand basal area and growth of new stump sprouts were also simulated. Stands quickly returned to preharvest stocking after light cutting, implying that heavy or frequent light cutting is needed to sustain growth and vigor of regeneration in multiaged coast redwood stands.

Young-Growth Redwood Stands Respond Well to Various Thinning Intensities

1994 ◽  
Vol 9 (4) ◽  
pp. 106-112 ◽  
Author(s):  
William W. Oliver ◽  
James L. Lindquist ◽  
Rudolph O. Strothmann
Keyword(s):  
Basal Area ◽  
Stand Density ◽  
Significant Loss ◽  
Substantial Portion ◽  
Stand Growth ◽  
Growing Stock ◽  
Stump Sprouting ◽  
Volume Production ◽  
Young Growth ◽  
Area And Volume

Abstract Three 45- to 50-yr-old redwood (Sequoia sempervirens) sawtimber stands spanning a substantial portion of the species' commercial range were thinned to three stocking levels. Treatments were low thinnings leaving 25%, 50%, 75%, and 100% of the before-treatment stand density, expressed as basal area/ac. Trees were measured for dbh, and a sampling of heights was taken for volume estimations at 0, 5, 10, and 15 yr after thinning. Leave trees responded strongly to the increased growing space, in spite of the vigorous stump sprouting of cut trees. Stand growth in basal area and volume varied narrowly among treatments. Overall, volume production was significantly different only in the 25% leave plots where sites were not fully occupied by the leave trees. Results illustrate the similarity between two growth/growing stock theories which appear to conflict. We conclude that 50% of the basal area in fully stocked stands could be removed in a low thinning without significant loss in volume production. West. J. Appl. For. 9(4):106-112.

scholarly journals Carbon Sequestration Potentials of Man-made Grasslands under Different Pattern of Plantation Stands in West Bandung Regency, Indonesia

2021 ◽  
Vol 249 ◽  
pp. 03011
Author(s):  
Annas Dwitri Malik ◽  
Maulida Isfahani Nurillah ◽  
Parikesit ◽  
Susanti Withaningsih ◽  
Ratna Wingit
Keyword(s):  
Carbon Sequestration ◽  
Carbon Storage ◽  
Carbon Stock ◽  
Basal Area ◽  
Ground Cover ◽  
Allometric Equation ◽  
Tree Biomass ◽  
Management Planning ◽  
Grassland Ecosystems ◽  
Below Ground

Alternatives of vegetations to store carbon need to be encouraged considering that forests are threatened by widespread destructions. One such vegetation is grasslands which have the potential for carbon storage and to reduce CO2 concentration in the atmosphere. At present, many enterprises have designed grasslands for many purposes. Grasslands at Cikalong Wetan and Little Farmers, West Bandung Regency were established under different pattern of plantation stands. The purpose of this research was to study the potential of carbon stock in grassland vegetation at these locations. Based on RaCSA method, the tree biomass was determined by nondestructive collection of density and basal area of trees, then calculated by an allometric equation. The ground cover biomass was determined by destructive collection of grass and roots. Total measured biomass was multiplied by 46% to obtain carbon storage. Based on the results, the potential of carbon stock in Little Farmers grassland (159,540 ton ha-1) is higher than in Cikalong Wetan (14,482 ton ha-1). Carbon stored in tree biomass gives the highest contribution to overall carbon stock potential in Little Farmers (94.84%) while carbon stored in below-ground understorey biomass gives the highest contribution in Cikalong Wetan (52.13 %). Different management of grasslands and pattern of plantation stands resulting a different contribution of carbon stock in every carbon pool. In order to maintain the carbon sequestration potentials of these locations, an agroforestry management such as agri-silviculture need to be encouraged. This study gives a comparison of the carbon sequestration potentials between two man-made grassland ecosystems. For many enterprises this study will aid in a management planning of man-made grassland in terms of ecosystem services, that is carbon sequestration.

scholarly journals Determining the Optimal Density of Phoebe bournei Plantations Based on Dynamic Programming under Close-to-Nature Management Measures

2022 ◽  
Vol 14 (2) ◽  
pp. 847
Author(s):  
Danmei Wang ◽  
Jiping Li ◽  
Tao Tang
Keyword(s):  
Dynamic Programming ◽  
Programming Model ◽  
Basal Area ◽  
Stand Density ◽  
Nature Management ◽  
Growth Equation ◽  
Site Conditions ◽  
Stand Growth ◽  
Dynamic Programming Model ◽  
Phoebe Bournei

Close-to-nature management (CTNM) is the most promising option for plantation silviculture and has received widespread attention in recent years. Stand density is a key variable in CTNM, as it directly influences growth and yield. Research for the optimal density that maximizes the total harvest has been ongoing. In this paper, a dynamic programming model was applied to the CTNM of Phoebe bournei plantations for the first time to solve the problem of stand density and target tree density control. This paper took Phoebe bournei plantations in Jindong Forest Farm of Hunan Province as the research object. Based on the data of seven consecutive years from 2015 to 2021, Richard’s growth equation was used to fit the height growth equation and basal area growth equation of Phoebe bournei. Stand growth was divided into five development stages according to the forest growth process and characteristics. Stand density and basal area were selected as two-dimensional state variables, and the maximum total harvest in the entire stand growth process was used as the objective function to establish a dynamic programming model. The optimal stand density and target tree density at each growth stage of the stand under three different site conditions were determined. According to the results obtained, the objective forest shape was designed for the stand under three types of site conditions, which can provide a theoretical basis for the CTNM of Phoebe bournei plantations to make the stand achieve the maximum harvest.

Effects of intermediate silvicultural treatments on the distribution of within-stand growth

1994 ◽  
Vol 24 (2) ◽  
pp. 398-404 ◽  
Author(s):  
James A. Moore ◽  
Lianjun Zhang ◽  
James D. Newberry
Keyword(s):  
Stand Structure ◽  
Statistical Tests ◽  
Relative Size ◽  
Basal Area ◽  
Stand Density ◽  
Relative Distribution ◽  
Growth Responses ◽  
Stand Growth ◽  
Silvicultural Treatments ◽  
Individual Trees

The distribution of within-stand basal area growth following silvicultural treatments was investigated using a relative size–relative growth (RSG) function. The effects of thinning on the distribution of tree basal area, including changes in location or scale, can be incorporated into the estimation of the RSG function parameters. Additional stand growth due to fertilization can also be allocated to individual trees using the same RSG function, since the contribution of a tree's response to total stand treatment response depends on its relative size in the stand. Statistical tests and validation of the RSG function indicated that thinning and fertilization do not alter the characteristic relationships between tree size, stand density, stand structure, and the relative distribution of growth across size classes within a stand. Therefore, silvicultural treatment growth responses predicted at a whole-stand level of resolution can be disaggregated to a list of individual trees using the RSG function developed from untreated plots.

Comparative Study of Size, Total Protein, Fibrinogen and 5-HT Content of Human and Canine Platelet Density Subpopulations

1986 ◽  
Vol 56 (03) ◽  
pp. 288-292 ◽  
Author(s):  
Diego Mezzano ◽  
Eduardo Aranda ◽  
Arnaldo Foradori
Keyword(s):  
Comparative Study ◽  
Protein Content ◽  
Cell Density ◽  
Total Protein ◽  
Unit Volume ◽  
Low Density ◽  
Dense Bodies ◽  
Artifactual Changes ◽  
Platelet Release ◽  
The Difference

SummaryThe size, total protein, fibrinogen and 5-HT content were evaluated in density subpopulations of human and canine platelets fractionated in linear arabinogalactan gradients. The methodology was assessed to ascertain that platelet separation was by density and to discard artifactual changes and platelet release during the procedure. EDTA or PGEi increased the size of human PRP-platelets, but not of dog platelets. In humans, high density (HD) platelets were 1.26 times larger and contained 1.88 times more fibrinogen, 2.23 times more 5-HT and 1.37 times more protein than low density (LD) platelets; in dogs, these density cohorts did not differ in protein content, but LD platelets were 1.29 times larger and had 1.33 times more fibrinogen and 5-HT than HD platelets. These findings suggest that cell density is mostly dependent on the protein content per unit volume of platelets (and not on dense bodies). The differences in fibrinogen and 5-HT content between HD and LD cohorts in humans and dogs may be related to platelet age. The difference in volume between HD and LD platelets in dogs is of uncertain interpretation.

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