scholarly journals The influence of depth-to-groundwater on structure and productivity of Eucalyptus woodlands

2014 ◽  
Vol 62 (5) ◽  
pp. 428 ◽  
Author(s):  
Sepideh Zolfaghar ◽  
Randol Villalobos-Vega ◽  
James Cleverly ◽  
Melanie Zeppel ◽  
Rizwana Rumman ◽  
...  
Keyword(s):  
Aboveground Biomass ◽  
Net Primary Productivity ◽  
Basal Area ◽  
Tree Height ◽  
Stem Density ◽  
Aboveground Net Primary Productivity ◽  
Area Index ◽  
Mean Values ◽  
Huber Value ◽  
Eastern Australia

Although it is well documented that access to groundwater can help plants survive drought in arid and semiarid areas, there have been few studies in mesic environments that have evaluated variation of vegetation characteristics across a naturally occurring gradient in depth-to-groundwater (DGW). The aim of this study was to determine whether differences in groundwater depth influence structural attributes and productivity of remnant woodlands in south-eastern Australia. The study area was located in the Kangaloon bore-field area of New South Wales, where DGW varies from 2.4 m to 37.5 m and rainfall is plentiful. We examined structural (leaf-area index, basal area, stem density, tree height, Huber value (HV) and aboveground biomass) and functional (aboveground net primary productivity (ANPP)) attributes of seven woodland sites differing in DGW. We also used ∂13C analysis of sapwood across six sites, along with observed non-linear changes in structural attributes, to infer groundwater use by trees. Significant differences in structural attributes and ANPP were observed across sites. The three shallowest sites with 2.4 m, 4.3 m and 5.5 m DWG had significantly larger aboveground biomass and ANPP than did the four deepest sites (DGW ≥9.8 m). Across all attributes (except HV in the summer, where the mean values were significantly larger at sites where DGW was 5.5 m or less and across the four deeper sites (DGW ≥9.8 m), there were no differences in these three structural traits, nor in ANPP. Despite finding no significant differences in HV across sites in the summer, in winter, the two deepest sites had a significantly larger HV than did the two shallowest sites. Significant increases in ∂13C of sapwood occurred across five of the six sites, consistent with increasing water-use efficiency as DGW increased, reflecting the declining availability of groundwater with increasing DGW. This study has demonstrated that even in a mesic environment, putative access to groundwater can have important impacts on structural and functional traits of trees and, consequently, on woodland productivity.

scholarly journals Identifying Variables to Discriminate between Conserved and Degraded Forest and to Quantify the Differences in Biomass

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1020
Author(s):  
Yan Gao ◽  
Margaret Skutsch ◽  
Diana Laura Jiménez Rodríguez ◽  
Jonathan V. Solórzano
Keyword(s):  
Aboveground Biomass ◽  
Tropical Dry Forest ◽  
Canopy Cover ◽  
Basal Area ◽  
Tree Height ◽  
Dry Forest ◽  
Rank Test ◽  
Degraded Forest ◽  
Forest Survey ◽  
Structural Variables

The purpose of this work was to determine which structural variables present statistically significant differences between degraded and conserved tropical dry forest through a statistical study of forest survey data. The forest survey was carried out in a tropical dry forest in the watershed of the River Ayuquila, Jalisco state, Mexico between May and June of 2019, when data were collected in 36 plots of 500 m2. The sample was designed to include tropical dry forests in two conditions: degraded and conserved. In each plot, data collected included diameter at breast height, tree height, number of trees, number of branches, canopy cover, basal area, and aboveground biomass. Using the Wilcoxon signed-rank test, we show that there are significant differences in canopy cover, tree height, basal area, and aboveground biomass between degraded and conserved tropical dry forest. Among these structural variables, canopy cover and mean height separate conserved and degraded forests with the highest accuracy (both at 80.7%). We also tested which variables best correlate with aboveground biomass, with a view to determining how carbon loss in degraded forest can be quantified at a larger scale using remote sensing. We found that canopy cover, tree height, and density of trees all show good correlation with biomass and these variables could be used to estimate changes in biomass stocks in degraded forests. The results of our analysis will help to increase the accuracy in estimating aboveground biomass, contribute to the ongoing work on REDD+, and help to reduce the great uncertainty in estimation of emissions from forest degradation.

Forest sampling combining fixed- and variable-radius sample plots

2007 ◽  
Vol 37 (8) ◽  
pp. 1460-1471 ◽  
Author(s):  
Kevin C. Packard ◽  
Philip J. Radtke
Keyword(s):  
Basal Area ◽  
Sampling Strategy ◽  
Tree Height ◽  
Model Parameters ◽  
Stem Density ◽  
Variable Radius ◽  
Plot Sampling ◽  
Allowable Error ◽  
Fixed Radius ◽  
Volume Equation

We examine the statistical properties of a forest sampling strategy that combines methods of fixed- and variable-radius plot sampling. Circular fixed-radius plots are established at the same locations as variable-radius plots to take advantage of their known efficiencies for unbiasedly estimating stem density and basal area, respectively. The design eliminates the need for measuring stem diameters, except to check borderline trees on variable-radius plots. Separate controls on allowable error for stem density and basal area estimates are possible. An unbiased estimator of volume (Vol) is derived that uses an existing volume equation having the form Vol = a + bd2h, where d is tree diameter at breast height, h is tree height, and a and b are model parameters. Calculation of volume requires only the measurement of heights for those trees tallied on the variable-radius plots. Properties of the estimator are demonstrated for a mixed-species hardwood forest in the southern Appalachian Mountains of North Carolina, USA.

Aboveground biomass and seasonal patterns of aboveground net primary productivity in five bamboo species in northern Laos

2019 ◽  
Vol 13 (2) ◽  
pp. 150-156
Author(s):  
Singkone Xayalath ◽  
Isao Hirota ◽  
Shinsuke Tomita ◽  
Michiko Nakagawa
Keyword(s):  
Climate Change ◽  
Primary Productivity ◽  
Aboveground Biomass ◽  
Net Primary Productivity ◽  
Seasonal Patterns ◽  
Bamboo Species ◽  
Aboveground Net Primary Productivity ◽  
Sympatric Distribution ◽  
Carbon Sequestration Potential ◽  
Sequestration Potential

Abstract Aims Accurate estimates of bamboo biomass and net primary productivity (NPP) are required to evaluate the carbon sequestration potential of bamboo forests. However, relevant data that are important for climate change mitigation, have rarely been collected in regions outside of East Asia and India. Information on seasonal patterns of NPP and its components will enable the quantification of factors that influence the carbon balance in bamboo forests. In this study, we quantified the aboveground biomass (AGB) and aboveground NPP of five major bamboo species in northern Laos using monthly data collected over a 12-month period. Methods All live culms in 10, 2 m × 2 m plots (for one monopodial bamboo species: Indosasa sinica) and 30 clumps per species (for four sympodial bamboo species: Bambusa tulda, Cephalostachyum virgatum, Dendrocalamus membranaceus and Gigantochloa sp.) were numbered and measured at breast height. We set 10 or 20 litter traps per species to collect litterfall. Censuses of dead and recruited culms and litterfall collection were performed once per month for 12 months. Important Findings The AGB was highest in I. sinica (59.87 Mg ha−1) and lowest in C. virgatum (11.54 Mg ha−1), and was mostly below the plausible global range for bamboos (32–256 Mg ha−1). The sympatric distribution of multiple bamboo species at the study sites may have suppressed the AGB in four of the five studied species. The aboveground NPP estimates were between 3.43 and 14.25 Mg ha−1 yr−1; those for D. membranaceus (8.20 Mg ha−1 yr−1) and I. sinica (14.25 Mg ha−1 yr−1) were comparable to mean global estimates for temperate evergreen forests (8.78 Mg ha−1 yr−1) and tropical moist forests (10.56 Mg ha−1 yr−1). High culm recruitment rates (15.20–23.39% yr−1) were major contributors to aboveground NPP estimates. Seasonal patterns of aboveground NPP were largely influenced by the phenology of the new culms. In the four sympodial bamboo species, new culms began to emerge following the onset of persistent rainfall, mainly in July and August. However, the sprouting of new culms in the monopodial species I. sinica followed a trend of increasing temperatures, mainly in March and April. Thus, our results indicate that bamboos have considerable potential for sequestering carbon in northern Laos, but that this potential may be affected by climate change.

scholarly journals Concerted changes in tropical forest structure and dynamics: evidence from 50 South American long-term plots

2004 ◽  
Vol 359 (1443) ◽  
pp. 421-436 ◽  
Author(s):  
S. L. Lewis ◽  
O. L. Phillips ◽  
T. R. Baker ◽  
J. Lloyd ◽  
Y. Malhi ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Net Primary Productivity ◽  
Basal Area ◽  
Mortality Rates ◽  
Stem Density ◽  
Cross Sectional ◽  
The Cross ◽  
Stem Mortality ◽  
Over Time

Several widespread changes in the ecology of old–growth tropical forests have recently been documented for the late twentieth century, in particular an increase in stem turnover (pan–tropical), and an increase in above–ground biomass (neotropical). Whether these changes are synchronous and whether changes in growth are also occurring is not known. We analysed stand–level changes within 50 long–term monitoring plots from across South America spanning 1971–2002. We show that: (i) basal area (BA: sum of the cross–sectional areas of all trees in a plot) increased significantly over time (by 0.10 ±; 0.04 m 2 ha −1 yr −1 , mean ± 95%CI) as did both (ii) stand–level BA growth rates (sum of the increments of BA of surviving trees and BA of new trees that recruited into a plot); and (iii) stand–level BA mortality rates (sum of the cross–sectional areas of all trees that died in a plot). Similar patterns were observed on a per–stem basis: (i) stem density (number of stems per hectare; 1 hectare is 10 4 m 2 ) increased significantly over time ( 0.94 ± 0.63 stems ha −1 yr −1 ); as did both (ii) stem recruitment rates; and (iii) stem mortality rates. In relative terms, the pools of BA and stem density increased by 0.38 ± 0.15% and 0.18 ± 0.12% yr −1 , respectively. The fluxes into and out of these pools—stand–level BA growth, stand–level BA mortality, stem recruitment and stem mortality rates—increased, in relative terms, by an order of magnitude more. The gain terms (BA growth, stem recruitment) consistently exceeded the loss terms (BA loss, stem mortality) throughout the period, suggesting that whatever process is driving these changes was already acting before the plot network was established. Large long–term increases in stand–level BA growth and simultaneous increases in stand BA and stem density imply a continent–wide increase in resource availability which is increasing net primary productivity and altering forest dynamics. Continent–wide changes in incoming solar radiation, and increases in atmospheric concentrations of CO 2 and air temperatures may have increased resource supply over recent decades, thus causing accelerated growth and increased dynamism across the world's largest tract of tropical forest.

scholarly journals Causes and Consequences of Alternative Successional Trajectories Following the 1988 Yellowstone Fires

1999 ◽  
Vol 23 ◽  
pp. 143-145
Author(s):  
Monica Turner ◽  
William Romme ◽  
Dennis Knight ◽  
Daniel Tinker
Keyword(s):  
Spatial Patterns ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Ecosystem Processes ◽  
Seedling Density ◽  
Aboveground Net Primary Productivity ◽  
Tree Seedling ◽  
Area Index ◽  
Sapling Density ◽  
Tree Sapling

The 1988 Yellowstone fires created a strikingly heterogeneous pattern of severely burned, lightly burned, and unburned forests across a large portion of Yellowstone's subalpine Plateau (Turner et al. 1994). Equally striking has been the variation in post-fire tree seedling density throughout the burned forests. In 1999 we initiated a 3-year study of post­fire succession, with three principal objectives: (1) to document the variation in post-fire tree sapling density and to map the spatial patterns of sapling density (2) to explain the causes of the variation in post­fire sapling density (3) to explore the consequences of variable post-fire sapling density for ecosystem processes, specifically aboveground net primary productivity (ANPP) and leaf area index (LAI).

scholarly journals La densidad, riqueza y composición arbóreas definen parches detectados remotamente en una selva subperennifolia

2019 ◽  
Vol 67 (4) ◽  
Author(s):  
Alejandra del Pilar Ochoa-Franco ◽  
José René Valdez-Lazalde ◽  
Héctor Manuel De los Santos-Posadas ◽  
José Luis Hernández-Stefanoni ◽  
Juan Ignacio Valdez-Hernández ◽  
...  
Keyword(s):  
Species Richness ◽  
Vegetation Structure ◽  
Basal Area ◽  
Selective Logging ◽  
Stem Density ◽  
Importance Value ◽  
Vegetation Patch ◽  
Mean Values ◽  
Specific Composition ◽  
Vegetation Patches

A proposal for characterizing habitat of forests, obtained from an object-oriented classification of a RapidEye multiespectral imagery, based on dissimilarity matrices of vegetation structure, species diversity and composition is presented. The study area is a forested landscape mosaic after slash and burn agriculture (Ac: 8-23 years ago), selective logging (Fs: 43-53 years ago), and selective logging and forest fire (Fc: 21-28 years ago). The site is located in the central part of Quintana Roo, México, where three vegetation patches were delineated according to remotely sensed multiespectral imagery. Mean differences between vegetation structure properties of each vegetation patch were obtained through a permutational multivariate analysis of variance (p <0.001). Species richness, stem density per hectare, and the axis-1 scores of the non-metric multidimensional scaling ordination of specific composition were identified as the vegetation attributes more relevant to differentiate the vegetation patches by a multinomial logistic model. Fc vegetation patch is characterized by the greatest mean values on Shannon-Wiener index, species richness, and stem density. The Fs has the greatest mean values of canopy height, basal area and biomass at 80 percentile, and the Ac vegetation patch has the lowest values of all mentioned metrics. The species with the greatest relative importance value were: Ac: Bursera simaruba and Psidia psipula, Fs: Gymnanthes lucida andManilkara zapota, Fc: G. lucida and B. simaruba. The uncertainty associated with the metrics assessed by vegetation patch was smaller than the uncertainty of the whole area, because of the efficient variability aggregation of the field data. We conclude that multiespectral information is a reliable tool for distinguishing vegetation patches with specific features, as stem density, specific composition, and species richness.

Canopy profiles of some Piedmont hardwood forests

1988 ◽  
Vol 18 (8) ◽  
pp. 1090-1093 ◽  
Author(s):  
Craig Wallace Hedman ◽  
Dan Binkley
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Net Primary Productivity ◽  
Hardwood Forests ◽  
Site Quality ◽  
Aboveground Net Primary Productivity ◽  
Total Leaf Area ◽  
Area Index ◽  
Total Leaf ◽  
Site Fertility

Relationships between canopy profiles and site quality were examined in 11 old, uneven-aged (>180 years) hardwood forests in the Piedmont of eastern North Carolina. Site fertility was indexed by extractable soil calcium and phosphorus, by the content of calcium, phosphorus and nitrogen in litter fall, and by the aboveground net primary productivity of each stand. Canopy profiles were indexed by the leaf area index for each 3.3-m height interval. Total leaf area index correlated highly with most measures of site fertility, but we found no clear patterns between canopy profiles and any measure of site fertility. We conclude that site fertility is reflected in broad ecosystem-level variables such as total leaf area index and stand productivity, but that detailed patterns such as canopy profiles relate strongly to specific stand composition, age structure, and history.

scholarly journals Growth assessment of upper hill dipterocarp (Shorea platyclados) at the various slope in a rehabilitated landscape

2021 ◽  
Vol 914 (1) ◽  
pp. 012027
Author(s):  
F Reksawinata ◽  
P Pamoengkas ◽  
H H Rachmat
Keyword(s):  
Growth Performance ◽  
Basal Area ◽  
Tree Height ◽  
Average Diameter ◽  
Stem Diameter ◽  
Average Height ◽  
Annual Increment ◽  
Area Index ◽  
Shorea Platyclados ◽  
Mean Annual Increment

Abstract Rehabilitation aims to improve landscape function while increasing its resilience to climate change. Gunung Dahu research forest is a rehabilitated hilly landscape that is planted with more than 25 dipterocarp species, including an upper hill dipterocarp tree of Shorea platyclados at various site conditions. This study aimed to assess the growth performance of S. platyclados at five sloping levels class of 0-8%, 8-15%, 15-25%, 25-45%, and >45%. Observed growth attributes were stem diameter, total height, basal area, Mean Annual Increment (MAI), and Leaf Area Index (LAI), and diameter. The results showed that sloping levels significantly affect the growth performance of the planted trees. The highest slope level (>45%) supported the highest average stem diameter and tree height (41.48 cm and 20.86 m). The sloping level of >45%, 25-45%, 15-25%, 8-15%, and 0-8% yield different value of average diameter which were 41.48 cm, 35.86 cm, 36.54 cm, 34.61 cm, and 31.23, while the average height were 20, 86m, 19.78 m, 16.72 m, 18.84 m, 18.61 m respectively. Thus, the upper hill dipterocarp of S. platyclados is a prospective native tree species for rehabilitating hilly upland landscapes.

Biomass, productivity, and nutrient-use efficiency of aboveground vegetation in four Rocky Mountain coniferous forests

1989 ◽  
Vol 19 (3) ◽  
pp. 309-317 ◽  
Author(s):  
Cindy E. Prescott ◽  
John P. Corbin ◽  
Dennis Parkinson
Keyword(s):  
Aboveground Biomass ◽  
Net Primary Productivity ◽  
Nutrient Use Efficiency ◽  
Pine Forest ◽  
Ground Vegetation ◽  
P Efficiency ◽  
Aboveground Net Primary Productivity ◽  
Nitrogen And Phosphorus ◽  
Nutrient Use ◽  
Use Efficiency

Aboveground biomass, annual production, and internal nitrogen and phosphorus dynamics of vegetation were compared among a 90-year-old Pinuscontorta Loudon forest, a 120-year-old Piceaglauca (Moench) Voss–P. contorta forest, a 350-year-old Piceaengelmannii Parry ex Engelm.–Abieslasiocarpa (Hook.) Nutt. forest, and a 13-year-old P. contorta stand in the Rocky Mountains of southwestern Alberta. Aboveground biomass of vegetation ranged from 109 to 203 t•ha−1, while aboveground net primary productivity ranged from 4.4 to 5.3 t•ha−1•year−1 in the mature forests. Approximately 30% of the N and 20–40% of the P in ground vegetation were reabsorbed during senescence; 40–50% of the N and 50–80% of the P were reabsorbed from senescing tree foliage. Annual uptake of nutrients (production minus reabsorption) was between 1.8 and 2.2 g•m−2•year−1 for N and 0.2–0.4 g•m−2•year−1 for P. Efficiency of nutrient use (milligrams of new biomass produced per milligram of nutrient taken up in 1 year) ranged from 249 to 262 for N and 1604 to 2355 for P in the mature forests, and 72 and 642, respectively, in the young pine stand. Both N and P were used very efficiently in the pine forest and relatively inefficiently in the spruce–pine forest, reflecting differences in the inherent nutrient-use efficiency of these tree species. In the spruce–fir forest, N was used less efficiently and P more efficiently than in other forests, in response to lower phosphorus availability in this forest. Differences in nutrient-use efficiency of vegetation were related to differences in the amount of biomass produced per unit amount of N or P taken up, and not to differences in efficiency of N or P reabsorption.

Quantitative assessment of stand condition and its relationship to physiological stress in stands of Eucalyptus camaldulensis (Myrtaceae)

2007 ◽  
Vol 55 (7) ◽  
pp. 692 ◽  
Author(s):  
Shaun C. Cunningham ◽  
Jennifer Read ◽  
Patrick J. Baker ◽  
Ralph Mac Nally
Keyword(s):  
Physiological Stress ◽  
Basal Area ◽  
Eucalyptus Camaldulensis ◽  
River Regulation ◽  
Area Index ◽  
Physiological Variables ◽  
Murray River ◽  
Eastern Australia ◽  
Plant Area Index ◽  
Eucalyptus Camaldulensis Dehnh

River regulation has led to a decline in the condition of Australia’s dominant riverine tree species, Eucalyptus camaldulensis Dehnh., in the Murray–Darling Basin. A quantitative method of assessing the condition of these important riparian forests is required for effective monitoring and management. A range of stand structural, morphological and physiological variables was measured in stands of contrasting condition along the Murray River in south-eastern Australia. Percentage live basal area, plant area index and crown vigour were found to be reliable, objective indicators of stand condition. Little difference was detected in the physiological performance of trees in terms of water potential and chlorophyll fluorescence among stands of good and poor condition.

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