Spatial Variation in Dominant Height and Basal Area Development in a Coast Redwood Forest: Implications for Inventory and Modeling

2015 ◽  
Vol 04 (04) ◽  
Author(s):  
John-Pascal Berrill ◽  
Kevin L O’Hara
Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 556
Author(s):  
Mauricio Zapata-Cuartas ◽  
Bronson P. Bullock ◽  
Cristian R. Montes ◽  
Michael B. Kane

Intensive loblolly pine (Pinus taeda L.) plantation management in the southeastern United States includes mid-rotation silvicultural practices (MRSP) like thinning, fertilization, competitive vegetation control, and their combinations. Consistent and well-designed long-term studies considering interactions of MRSP are required to produce accurate projections and evaluate management decisions. Here we use longitudinal data from the regional Mid-Rotation Treatment study established by the Plantation Management Research Cooperative (PMRC) at the University of Georgia across the southeast U.S. to fit and validate a new dynamic model system rooted in theoretical and biological principles. A Weibull pdf was used as a modifier function coupled with the basal area growth model. The growth model system and error projection functions were estimated simultaneously. The new formulation results in a compatible and consistent growth and yield system and provides temporal responses to treatment. The results indicated that the model projections reproduce the observed behavior of stand characteristics. The model has high predictive accuracy (the cross-validation variance explained was 96.2%, 99.7%, and 98.6%; and the prediction root mean square distance was 0.704 m, 19.1 trees ha−1, and 1.03 m2ha−1 for dominant height (DH), trees per hectare (N), and basal area (BA), respectively), and can be used to project the current stand attributes following combinations of MRSP and with different thinning intensities. Simulations across southern physiographic regions allow us to conclude that the most overall ranking of MRSP after thinning is fertilization + competitive vegetation control (Fert + CVC) > fertilization only (Fert) > competitive vegetation control only (CVC), and Fert + CVC show less than additive effect. Because of the model structure, the response to treatment changes with location, age of application, and dominant height growth as indicators of site quality. Therefore, the proposed model adequately represents regional growth conditions.


2021 ◽  
Author(s):  
Yihan Cai ◽  
Takahiro Nishimura ◽  
Hideyuki Ida ◽  
Mitsuru Hirota

<p> Soil respiration (Rs) is the second largest carbon flux between the atmosphere and terrestrial ecosystem. Because of the large proportion, even small change in Rs would considerably impact the global carbon cycle. Therefore, it is important to accurately estimate Rs by taking its spatial and temporal variation into consideration. While the temporal variation of Rs and its controlling factors have been well-described, large unexplainable part still has been remained in the spatial variation of Rs especially in the forest ecosystems with complex structures. The objective of this study is to fill the knowledge gap about spatial variation of Rs and its controlling factors in a typical mature beech forest in Japan. Hypotheses of this study were, 1) Rs would show large spatial variation in the mature beech forest, 2) the spatial variation of Rs was mainly influenced by soil water content (SWC) and soil temperature (ST), 3) the two key factors were determined by the forest structures. This study was conducted in a 1- ha permanent study plot in the mature beech forest with significant gap-mosaic structures. To examine these hypotheses, Rs, SWC, ST and parameters related to forest structure, i.e. sum of basal area, diameter at breast height, number of trees, number of species within a radius of 5 m from the Rs measurement points, and canopy openness were measured at 121 points in different season between 2012 to 2013. In this study, all the measurements of Rs were conducted by using alkali-absorption technique.</p><p> Coefficient of variation of Rs was between 25 - 28 % which was similar to that of SWC in all the measurements. The spatial variation of Rs was relatively higher in July, August and September than that in June and October. There was no significant relationship in the spatial variation between Rs and ST in all the measurements, meanwhile, Rs was well explained by SWC in measurements conducted in August, September and October. Multiple linear regression analysis indicated that canopy openness and sum of basal area showed significant positive and negative correlation with SWC, respectively. And canopy openness explained SWC much more than sum of basal area did. This result suggested that SWC, the key factor determined the spatial variation of Rs, cannot be only explained by stems distribution and their characteristics, but also canopy architecture in the forest ecosystem.</p>


2002 ◽  
Vol 32 (11) ◽  
pp. 1984-1991 ◽  
Author(s):  
Michael A Battaglia ◽  
Pu Mou ◽  
Brian Palik ◽  
Robert J Mitchell

Spatial aggregation of forest structure strongly regulates understory light and its spatial variation in longleaf pine (Pinus palustris Mill.) forest ecosystems. Previous studies have demonstrated that light availability strongly influences longleaf pine seedling growth. In this study, the relationship between spatial structure of a longleaf pine forest and spatial pattern of understory light availability were investigated by comparing three retention harvest treatments: single-tree, small-group, large-group, and an uncut control. The harvests retained similar residual basal area but the spatial patterns of the residual trees differed. Hemispherical photographs were taken at 300 stations to calculate gap light index (GLI), an estimate of understory light availability. Stand-level mean, variation, and spatial distribution of GLI were determined for each treatment. By aggregating residual trees, stand mean GLI increased by 20%, as well as its spatial variation. Spatial autocorrelation of GLI increased as the size of the canopy gaps increased and the gaps were better defined; thus, the predictability of GLI was enhanced. The ranges of detrended semivariograms were increased from the control to the large-group harvest indicating the spatial patterns of understory GLI became coarser textured. Our results demonstrated that aggregated canopy structure of longleaf pine forest will facilitate longleaf pine seedling regeneration.


FLORESTA ◽  
2002 ◽  
Vol 32 (1) ◽  
Author(s):  
Sebastião Do Amaral Machado ◽  
Ana Elizabete N. Tonon ◽  
Afonso Figueiredo Filho ◽  
Edilson Batista Oliveira

Foram analisados os efeitos de quatro densidades iniciais (2, 4, 8 e 25,15 mil plantas por hectare) e de 3 classes de sítio, cujos índices de sítios são 10,2; 13,5 e 16,8 m de altura dominante aos 7 anos de idade, sobre a área basal e volume por hectare em povoamentos nativos de bracatinga (Mimosa scabrella Benth.) na região metropolitana de Curitiba. Os dados provieram de um experimento de densidades em blocos ao acaso medidos nas idades de 4,1; 5,1; 6,3 e 7,6 anos. Os efeitos da densidade inicial e do sítio sobre a área basal (G) e volume (V) por hectare foram verificados através de análise de variância seguida do teste de Tukey, quando pertinente. A densidade inicial de 4 mil plantas por hectare gerou maiores valores de G e V nas últimas idades de medição. A área basal/ha não sofreu efeitos significativos do sítio em nenhuma das medições, enquanto que o volume/ha foi afetado por este fator (sítio) até a idade de 6,3 anos. Evolution of Basal Area and Volume per Hectare in Native "Bracatingais" Submited to Different Initial Densities and Different Sites Abstract The objectives of this research were to study the effects of four initial densities (2000, 4000, 8000 and 25150 plants/ha) and three site classes (site index 10.2, 13.5 and 16.8 m of dominant height at age seven) on basal area (G) and volume per hectare (V) for native stands of bracatinga (Mimosa scabrella Benth.) in the Metropolitan Region of Curitiba, Brazil. The data set came from permanent sample plots of a density trial established in a random blocks design. These plots were measured at ages 4.1, 5.1, 6.3, and 7.6 years of age. The effects of initial density and site on basal area and volume per hectare were verified through graphics and analysis of variance followed by the Tukey test when necessary. The initial density of 4,000 plants/ha generated the highest values of basal area and volume in the last ages of measurement. The basal area/ha did not sufered significative effects of site at any one of the measurement ages, while volume/ha was affected by this factor (site) until the age of 6.3 years.


2006 ◽  
Vol 30 (3) ◽  
pp. 147-153 ◽  
Author(s):  
Ralph L. Amateis ◽  
Stephen P. Prisley ◽  
Harold E. Burkhart ◽  
Jiping Liu

Abstract Analysis of loblolly pine plantation permanent plot data established across the southeastern United States indicates that differences in dominant height and stand basal area may be related to geographic locale as well as physiographic region. In general, holding other factors constant,plantations at southern latitudes and eastern longitudes have less basal area than plantations at northern latitudes and western longitudes. Plantations at southern latitudes and eastern longitudes in the Atlantic Coastal Plain are generally taller than elsewhere in the Atlantic Coastal Plain.These trends were consistent for a younger population of intensively managed plantations, as well as for an older population of nonintensively managed plantations. Regression equations were developed to test the significance of geographic location on the prediction of basal area and dominantheight. Even in the presence of stand variables that are highly correlated with basal area and dominant height, latitude and longitude were highly significant predictors. Including them as predictor variables increased considerably the precision of the regression equations. South. J. Appl.For. 30(3):142–146.


1974 ◽  
Vol 4 (1) ◽  
pp. 127-137
Author(s):  
S. Popovich

This paper presents a method of evaluating site productivity by volume per square foot of basal area, comparing it with the method of dominant height. Based on this method, this study also offers tables for estimating the production of plantations in relation to the average height, the average form quotient, and to the average basal area of the stand. Moreover, this study gives practical instructions about several factors influencing growth and yield of white spruce (Piceaglauca, Moench.) plantations in the province of Quebec.


1999 ◽  
Vol 29 (7) ◽  
pp. 979-984 ◽  
Author(s):  
Dwight K Lauer ◽  
Glenn R Glover

The relationship between age-5 pine height and vegetation cover was estimated for loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.) stands using regression analysis. This paper utilizes results from four locations of a vegetation control study that included herbicide treatments to control woody shrub and herbaceous vegetation. Age-5 average dominant height was predicted from first-year herbaceous cover, untreated first-year shrub cover, and fifth-year shrub cover. Dominant height increased 0.5 m for each decrease of about 30% in either first year herbaceous cover, untreated first-year shrub cover, or year-5 shrub cover. Lack of vegetation control on beds where vegetation was allowed to recolonize before planting reduced dominant height an additional 0.5 m. A competition index was constructed that estimates the difference between "potential" and actual age-5 pine height. Stand-level models were developed to link age-5 pine height and occupancy of competing vegetation to quadratic mean DBH, specific DBH percentiles, and stand basal area. The effects of interspecific competition on stand basal area and diameter percentiles could be accounted for through the effects of competing vegetation on dominant height except for treatments that did not control woody shrubs.


1998 ◽  
Vol 28 (9) ◽  
pp. 1344-1351 ◽  
Author(s):  
Hubert Sterba ◽  
Ralph L Amateis

Crown efficiency was first defined by Assmann (1961. Waldertragskunde. BLV, München) as individual tree volume increment per unit of crown projection area. He hypothesized that within a given crown class, smaller crowns are more efficient because their ratio between crown surface and horizontal crown projection is higher. Data from a loblolly pine (Pinus taeda L.) spacing experiment were used to test if this hypothesis also holds in young loblolly pine stands and, if so, to determine if it explains the increment differences between spacings in the spacing experiment. Using individual tree height relative to plot dominant height to describe crown class, within-plot regression showed that crown efficiency decreased with crown size for trees below dominant height. This relationship was much less pronounced than indicated from Assmann's examples, although the crown surface to crown projection ratio behaved in the same way as Assmann had hypothesized. Crown efficiency as well as the crown surface to crown projection area ratio decreased with increasing density. Basal area increment per hectare increased until total crown closure approached 130% and then stayed constant. This major impact of total crown coverage brings into question the usefullness of crown efficiency as an indicator for unit area growth.


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