scholarly journals Development of Forest Structure and Leaf Area in Secondary Forests Regenerating on Abandoned Pastures in Central Amazônia

2005 ◽  
Vol 9 (6) ◽  
pp. 1-22 ◽  
Author(s):  
Ted R. Feldpausch ◽  
Susan J. Riha ◽  
Erick C. M. Fernandes ◽  
Elisa V. Wandelli
Keyword(s):  
Leaf Area ◽  
Forest Structure ◽  
Small Diameter ◽  
Canopy Cover ◽  
Basal Area ◽  
Primary Forest ◽  
Stem Density ◽  
Total Biomass ◽  
Area Index ◽  
Slash And Burn

Abstract The area of secondary forest (SF) regenerating from pastures is increasing in the Amazon basin; however, the return of forest and canopy structure following abandonment is not well understood. This study examined the development of leaf area index (LAI), canopy cover, aboveground biomass, stem density, diameter at breast height (DBH), and basal area (BA) by growth form and diameter class for 10 SFs regenerating from abandoned pastures. Biomass accrual was tree dominated, constituting ≥94% of the total measured biomass in all forests abandoned ≥4 to 6 yr. Vine biomass increased with forest age, but its relative contribution to total biomass decreased with time. The forests were dominated by the tree Vismia spp. (>50%). Tree stem density peaked after 6 to 8 yr (10 320 stems per hectare) before declining by 42% in the 12- to 14-yr-old SFs. Small-diameter tree stems in the 1–5-cm size class composed >58% of the total stems for all forests. After 12 to 14 yr, there was no significant leaf area below 150-cm height. Leaf area return (LAI = 3.2 after 12 to 14 yr) relative to biomass was slower than literature-reported recovery following slash-and-burn, where LAI can reach primary forest levels (LAI = 4–6) in 5 yr. After 12 to 14 yr, the colonizing vegetation returned some components of forest structure to values reported for primary forest. Basal area and LAI were 50%–60%, canopy cover and stem density were nearly 100%, and the rapid tree-dominated biomass accrual was 25%–50% of values reported for primary forest. Biomass accumulation may reach an asymptote earlier than expected because of even-aged, monospecific, untiered stand structure. The very slow leaf area accumulation relative to biomass and to reported values for recovery following slash-and-burn indicates a different canopy development pathway that warrants further investigation of causes (e.g., nutrient limitations, competition) and effects on processes such as evapotranspiration and soil water uptake, which would influence long-term recovery rates and have regional implications.

Biomass and leaf area in contrasting lodgepole pine forests

1984 ◽  
Vol 14 (2) ◽  
pp. 259-265 ◽  
Author(s):  
John A. Pearson ◽  
Timothy J. Fahey ◽  
Dennis H. Knight
Keyword(s):  
Leaf Area ◽  
Fine Roots ◽  
Lateral Root ◽  
Root Biomass ◽  
Basal Area ◽  
Pine Forests ◽  
Total Biomass ◽  
Area Index ◽  
Sapwood Area ◽  
Dimension Analysis

Bole, branch, foliage, root crown, and lateral root biomass of Pinuscontorta ssp. latifolia (Engelm. ex Wats.) Critchfield forests in southeastern Wyoming were estimated by a combination of aboveground dimension analysis, belowground planar intersect sampling, and soil coring. Total biomass of six stands ≥75 years old ranged from 123 to 180 Mg/ha, and roof:shoot ratios were much higher in two very dense stands than in four more open stands. Average proportions of biomass in boles, branches, foliage, woody roots, and fine roots were 61, 7, 6, 20, and 6%, respectively. Leaf area index ranged from 4.5 to 9.9. Leaf area per unit sapwood area ranged from 0.20 to 0.57 m2/cm2in stands of different densities, ages, and sites. Sapwood area was a more precise predictor of foliage biomass than was basal area for the low to moderate density stands, but was marginally inferior to basal area for two high density stands (>9000 trees/ha).

Biomass and Leaf-Area Estimates for Varnishleaf Ceanothus, Deerbrush, and Whiteleaf Manzanita

1987 ◽  
Vol 2 (4) ◽  
pp. 124-128 ◽  
Author(s):  
Thomas F. Hughes ◽  
Christopher R. Latt ◽  
John C. Tappeiner ◽  
Michael Newton
Keyword(s):  
Leaf Area ◽  
Site Occupancy ◽  
Basal Area ◽  
Stem Length ◽  
Stand Age ◽  
Leaf Biomass ◽  
Total Biomass ◽  
Regression Equations ◽  
Area Index ◽  
Highly Correlated

Abstract To help foresters assess site occupancy of seed-established stands of varnishleaf (Ceanothus velutinus var. laevigatus) deerbrush (Ceanothus integerrimus), and whiteleaf manzanita (Arctostaphylos viscida), we developed equations for estimating their aboveground biomass and leaf area. From 9 to 14 pure stands from 2 to 20 years old were selected for each species in southwest Oregon and northern California. Individual stems of Ceanothus species and whole bushes of manzanita were destructively sampled Regression equations for leaf and total biomass of manzanita plants and for stems of Ceanothus sp. showed that these variables were highly correlated with trunk or stem diameter (r² = 0.85 - 0.99). Total biomass, leaf biomass, and leaf area index (LAI) of stands can be estimated accurately from measurements of stem or trunk basal area (r² = 0.87 - 0.99). Stand age (yr) and average stem length (cm) are also reliable estimators (r² = 0.74 - 0.82). It appears that stands of varnishleaf attain a maximum LAI of 5.5 m²/m² by 7 years, whereas the maximum values for deer-brush and manzanita were 2.8 and 3.5, respectively, at about 15 years. Stands of all three species apparently continue to produce net biomass well beyond 16 years of age. West. J. Appl. For. 2(4):124-128, October 1987.

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

2016 ◽  
Vol 123 ◽  
pp. 195-202 ◽  
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

scholarly journals Algorithm for assessing forest stand productivity index using leaf area index

2019 ◽  
Vol 16 (3) ◽  
pp. 1311
Author(s):  
Faid Abdul Manan ◽  
Muhammad Buce Saleh ◽  
I Nengah Surati Jaya ◽  
Uus Saepul Mukarom
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Basal Area ◽  
Forest Stand ◽  
Productivity Index ◽  
Estimation Model ◽  
Area Index ◽  
Study Objective ◽  
Stand Productivity ◽  
Variable Combination

This paper describes a development of an algorithm for assessing stand productivity by considering the stand variables. Forest stand productivity is one of the crucial information that required to establish the business plan for unit management at the beginning of forest planning activity. The main study objective is to find out the most significant and accurate variable combination to be used for assessing the forest stand productivity, as well as to develop productivity estimation model based on leaf area index. The study found the best stand variable combination in assessing stand productivity were density of poles (X2), volume of commercial tree having diameter at breast height (dbh) 20-40 cm (X16), basal area of commercial tree of dbh >40 cm (X20) with Kappa Accuracy of 90.56% for classifying into 5 stand productivity classes. It was recognized that the examined algorithm provides excellent accuracy of 100% when the stand productivity was classified into only 3 classes. The best model for assessing the stand productivity index with leaf area index is y = 0.6214x - 0.9928 with R2= 0.71, where y is productivity index and x is leaf area index.

scholarly journals A PROPOSED METHODOLOGY FOR THE CORRECTION OF THE LEAF AREA INDEX MEASURED WITH A CEPTOMETER FOR PINUS AND EUCALYPTUS FORESTS

2016 ◽  
Vol 40 (5) ◽  
pp. 845-854 ◽  
Author(s):  
Domingos Mendes Lopes ◽  
Nigel Walford ◽  
Helder Viana ◽  
Carlos Roberto Sette Junior
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Correction Factor ◽  
Basal Area ◽  
Allometric Equations ◽  
Nutrient Cycle ◽  
Area Index ◽  
Physiological Processes ◽  
The Difference ◽  
Non Destructive

ABSTRACT Leaf area index (LAI) is an important parameter controlling many biological and physiological processes associated with vegetation on the Earth's surface, such as photosynthesis, respiration, transpiration, carbon and nutrient cycle and rainfall interception. LAI can be measured indirectly by sunfleck ceptometers in an easy and non-destructive way but this practical methodology tends to underestimated when measured by these instruments. Trying to correct this underestimation, some previous studies heave proposed the multiplication of the observed LAI value by a constant correction factor. The assumption of this work is LAI obtained from the allometric equations are not so problematic and can be used as a reference LAI to develop a new methodology to correct the ceptometer one. This new methodology indicates that the bias (the difference between the ceptometer and the reference LAI) is estimated as a function of the basal area per unit ground area and that bias is summed to the measured value. This study has proved that while the measured Pinus LAI needs a correction, there is no need for that correction for the Eucalyptus LAI. However, even for this last specie the proposed methodology gives closer estimations to the real LAI values.

Implementation constraints limit benefits of restoration treatments in mixed-conifer forests

2019 ◽  
Vol 28 (7) ◽  
pp. 495 ◽  
Author(s):  
Jamie M. Lydersen ◽  
Brandon M. Collins ◽  
Carolyn T. Hunsaker
Keyword(s):  
Sierra Nevada ◽  
Forest Structure ◽  
Forest Restoration ◽  
Tree Mortality ◽  
Canopy Cover ◽  
Basal Area ◽  
Severe Drought ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
Trade Offs

Forest restoration treatments seek to increase resilience to wildfire and a changing climate while avoiding negative impacts to the ecosystem. The extent and intensity of treatments are often constrained by operational considerations and concerns over uncertainty in the trade-offs of addressing different management goals. The recent (2012–15) extreme drought in California, USA, resulted in widespread tree mortality, particularly in the southern Sierra Nevada, and provided an opportunity to assess the effects of restoration treatments on forest resilience to drought. We assessed changes in mixed-conifer forest structure following thinning and understorey burning at the Kings River Experimental Watersheds in the southern Sierra Nevada, and how treatments, topography and forest structure related to tree mortality in the recent drought. Treatments had negligible effect on basal area, tree density and canopy cover. Following the recent drought, average basal area mortality within the watersheds ranged from 5 to 26% across riparian areas and 12 to 44% across upland areas, with a range of 0 to 95% across all plots. Tree mortality was not significantly influenced by restoration treatments or topography. Our results suggest that the constraints common to many restoration treatments may limit their ability to mitigate the impacts of severe drought.

Influence of Herbaceous Interference on Growth and Biomass Partitioning in Planted Loblolly Pine (Pinus taeda)

Weed Science ◽  
1990 ◽  
Vol 38 (6) ◽  
pp. 497-503 ◽  
Author(s):  
John R. Britt ◽  
Bruce R. Zutter ◽  
Robert J. Mitchell ◽  
Dean H. Gjerstad ◽  
John F. Dickson
Keyword(s):  
Leaf Area ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Growth Efficiency ◽  
Biomass Partitioning ◽  
Lower Percentage ◽  
Total Biomass ◽  
Growth Responses ◽  
Area Index ◽  
Weed Interference

Three herbaceous regimes were established, using herbicides, to examine the effects of interference on growth and biomass partitioning in loblolly pine (Pinus taedaL.). Trees were sampled near Auburn and Tallassee, AL. Trees at the Auburn site grown with low weed interference (LWI) had 4, 10, 10, 8, and 4 times greater total aboveground biomass than did trees with high weed interference (HWI) for ages one through five, respectively. Medium weed interference (MWI, Auburn site only) resulted in three times greater biomass the first 4 yr and two times greater total biomass by the fifth year compared to trees grown with HWI. Trees growing with LWI were 5, 8, 10, and 6 times larger than those with HWI for ages one through four, respectively, at the Tallassee site. At all levels of interference, the percentage of total biomass in foliage decreased, and stem and branch components increased, with increasing tree size at both sites. Trees growing with HWI had a lower percentage of total biomass in foliage and a greater percentage of total biomass in stem than those growing with LWI when compared over a common size. Growth efficiency per tree, expressed as annual increase in stem biomass per unit leaf area (g m−2), was slightly greater for trees growing with LWI compared to HWI when leaf area index (LAI3, total surface) was less than 0.2. For LAI values greater than 0.2 the relationship was reversed. The latter contradicts the idea that growth efficiency can be used as a measure of vigor for young loblolly pine. Changes in carbon partitioning to the development of leaf area are suggested to be driving the accelerated growth responses associated with a reduction of weed interference.

scholarly journals Genotypic Variation in Biomass Produced Is Linked to Differences in Radiation Acquisition in Mungbean

Proceedings ◽  
2019 ◽  
Vol 36 (1) ◽  
pp. 21
Author(s):  
Geetika ◽  
Rachaputi ◽  
Collins ◽  
Singh ◽  
Wenham ◽  
...  
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Genotypic Variation ◽  
Total Biomass ◽  
Potential Productivity ◽  
Area Index ◽  
Canopy Density ◽  
Significant Difference ◽  
Plant Densities ◽  
Rotation Crop

Mungbean has become an important cash and legume rotation crop in the Australian Northern Grains region. Thus, it is necessary to narrow the gap between potential productivity and actual production by understanding the crop physiological attributes contributing to the acquisition of radiation, and it’s conversion into total biomass. A field experiment was conducted at Gatton, during 2018-19 summer season, growing two commercial varieties of mungbean; Jade-AU and Satin II under irrigated conditions. The varieties were planted at 0.5m and 1.0m row spacing and different plant densities. Weekly biomass cuts were taken from a square meter and separated into its components. The area of a green leaf sub-sample was used to compute the leaf area of the canopy. Weekly Ceptometer measurements were taken above and below the canopy at noon on clear, sunny days to obtain a measure of Fraction of radiation interception (Fi). Total shoot dry matter (TDM), pod dry mater (PDM) and leaf area index (LAI) was investigated. There was a significant effect of canopy density on Fi. There was no significant difference in total dry matter between the two varieties, however, there was a highly significant effect of canopy density on TDM. . A highly significant variation in LAI amongst the two varieties and across canopy densities, with Satin II having a higher mean LAI compared to Jade-AU. There was significant effect of canopy density on PDM. Our data indicate variation in dry matter production across canopy densities and there is a need to examine varietal differences in radiation use efficiency which may provide better understanding of hot the captured radiation is utilized in biomass production in mungbean.

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 Pasture damage and regrowth from cattle treading

2000 ◽  
pp. 155-160 ◽  
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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