Estimation of aboveground herbaceous biomass using visually ranked digital photographs

2018 ◽  
Vol 40 (1) ◽  
pp. 9 ◽  
Author(s):  
Helen R. Morgan ◽  
Nick Reid ◽  
John T. Hunter
Keyword(s):  
New England ◽  
Arid Zone ◽  
Rank Order ◽  
Estimation Procedure ◽  
Dry Weight ◽  
Destructive Sampling ◽  
Actual Weight ◽  
Calibration And Validation ◽  
Herbaceous Biomass ◽  
Observer Drift

Methods for estimating aboveground herbaceous biomass in the field have generally involved calibrating visual estimates against clipped, dried and weighed biomass samples, requiring lengthy periods of estimation and destructive sampling in the field. Here we developed and tested a photographic estimation technique (PET) that minimises field time and provides accurate estimates of aboveground herbaceous biomass. Photographs of the biomass to be estimated taken in the field are ranked against calibration images of known biomass in the laboratory. The study was conducted in New South Wales, Australia, in grassy forest dells and grasslands at Booroolong Nature Reserve in the temperate New England Tablelands Bioregion and in semi-arid grassy shrubland on Naree Station in the arid Mulga Lands Bioregion. Photographs of quadrats containing the herbaceous biomass to be estimated were taken in successive years at both sites. Calibration and validation quadrats were also photographed, and the vegetation clipped, bagged, dried and weighed. The calibration and validation photographs were rank-ordered independently by three observers in terms of estimated dry weight, and the validation quadrats assigned a putative dry weight by reference to the known weights of the calibration images in the rank order. The accuracy of each observer’s estimates was assessed by regressing the estimated weight of each validation quadrat against the actual weight, which was withheld from the observer during the estimation procedure. Regression analysis of visually estimated weights on actual weights of validation quadrats yielded regression coefficients (R2) of 0.80–0.98 and 0.81–0.97 in the temperate-zone and arid-zone sites, respectively. PET was reliably used to visually estimate aboveground herbaceous biomass across a range of communities in two different climatic zones. The benefits of PET include reduced field time, minimisation of destructive sampling and avoidance of observer drift in estimating biomass in the field.

scholarly journals Allometric equation of local bamboo for estimating carbon sequestration of bamboo riparian forest

2021 ◽  
Vol 905 (1) ◽  
pp. 012002
Author(s):  
C Prayogo ◽  
C Muthahar ◽  
R M Ishaq
Keyword(s):  
Land Use ◽  
Carbon Sequestration ◽  
Riparian Forest ◽  
Dry Weight ◽  
Allometric Equation ◽  
Total Carbon ◽  
Destructive Sampling ◽  
Industrial Activities ◽  
Bamboo Stem ◽  
The Relationship

Abstract The cause of global warming is the increasing carbon concentration arising from industrial activities, burning of fossils, and land-use change. The purpose of this research was to find out the allometric equation to calculate the local bamboo biomass and then to be able to calculate how much carbon sequestration at bamboo riparian forest since this area was rarely being explored. The parameters observed were the height and diameter of the bamboo stem at 1.3 m height of 6 types of local bamboo using destructive sampling, along with the measurement of bamboo weight. The carbon content of the bamboo biomass, litter, and soil was measured to complement the estimation of total carbon sequestration. The results showed that the allometric equation for estimating local bamboo biomass is Y=0.6396 X1.6162 with R2=0.77, obtained from the relationship equations between dry weight and the diameter. Total carbon sequestration of this system ranged between 81 to 215 tons C ha−1.

Effects of oxygen and nitrate on ammonium uptake kinetics and adenylate pools in Phalaris arundinacea L. and Glyceria maxima (Hartm.) Holmb

1994 ◽  
Vol 102 ◽  
pp. 333-342 ◽  
Author(s):  
H. Brix ◽  
B. Lorenzen ◽  
J. T. Morris ◽  
H.-H. Schierup ◽  
B. K. Sorrell
Keyword(s):  
Adenine Nucleotide ◽  
Block Design ◽  
Energy Charge ◽  
Estimation Procedure ◽  
Dry Weight ◽  
Phalaris Arundinacea ◽  
Uptake Kinetics ◽  
Charge Ratio ◽  
Ammonium Uptake ◽  
Root Dry Weight

SynopsisWe studied the effects of oxygen (aerated versus O2 depleted ∼0.5 mg 1−1 O2) and nitrate (none versus 10 μmol 1−1) on the ammonium uptake kinetics and adenylate pools in two wetland plants differing in their degree of flood tolerance (Phalaris arundinacea L. and Glyceria maxima (Hartm.) Holmb.). The study was performed as a random block design in a growth chamber. The -uptake kinetics were estimated by using a computerised nonlinear parameter estimation procedure to fit the differential form of a modified Michaelis–Menten model to solution depletion curves. The uptake kinetics for differed between the two species: Vmax was significantly higher for P. arundinacea (24.7 to 29.6 μmol h−1 g−1 root dry weight) than for G. maxima (4.6–10.3 μmol h−1 g−1 root dry weight). The concentration at which uptake ceases (Cmin) was 0.2 to 0.5 μmol 1−1 for P. arundinacea and significant higher (1.1–2.7 μmol 1−1) for G. maxima.Km varied between 3.1 and 6.2 μmol 1−1 for P. arundinacea, and 1.6 and 3.0 μmol 1−1 for G. maxima. The different uptake kinetics of the two species reflect the different structure of their root systems: P. arundinacea has an extensive root system consisting of many thin roots whereas G. maxima has fewer but thicker roots. The uptake kinetics also suggest that P. arundinacea is adapted to growing at lower ambient concentrations than G. maxima. Oxygen had no consistent effect on uptake kinetics. However, the plants that had in the nutrient solution as well as had slightly higher Vmax values and lower Cmin and Km values than those without . Thus, both species were able to sustain their uptake characteristics at low external O2 concentrations, probably because of internal aeration through the air-space tissue of the plants. Nitrate deprivation also lowered the energy charge ratio and adenine nucleotide content in roots. The roots recovered quickly from deprivation once was resupplied. The stresses imposed by partially O2-depleted conditions and lack of nitrate were therefore relatively mild and reversible. It seems that the inherent aerenchyma development under aerated conditions in these species is sufficient to maintain adequate root oxygenation under partially O2-depleted conditions.

Diet and growth of rainbow trout, Salmo gairdneri Richardson, in two streams on the New England Tableland, New South Wales

1981 ◽  
Vol 32 (6) ◽  
pp. 967 ◽  
Author(s):  
RWJ Pidgeon
Keyword(s):  
Rainbow Trout ◽  
New England ◽  
New South ◽  
New South Wales ◽  
Rank Correlation ◽  
Dry Weight ◽  
Fish Growth ◽  
Salmo Gairdneri ◽  
Fish Size ◽  
South Wales

The diets and growth rates of rainbow trout in the Wollomombi and Guy Fawkes Rivers in northern New South Wales were examined. The growth rate of trout in the Wollomombi River was much higher than that of fish in the Guy Fawkes River. Spearman rank correlation coefficients indicated that stream type was more important than fish size in determining the composition of the diet of the trout. Benthic invertebrates formed the largest component of the diet in both streams: 66.0 and 63.0% of ash-free dry weight (AFDW) in the Wollomombi River and the Guy Fawkes River, respectively. Trout in the Wollomombi River consumed more nektonic prey (33.3% of AFDW) than fish in the Guy Fawkes River (3.7% of AFDW). In contrast, surface food (aquatic imagines and terrestrial insects) made up a much higher proportion of the diet of trout in the Guy Fawkes River (33.9% of AFDW) than in the Wollomombi River (0.6% of AFDW). Crayfish were a major component of the diet (in terms of AFDW) in both streams, their proportions increasing with fish size. The significance of crayfish in relation to fish growth is discussed.

scholarly journals Comparison of Hyperspectral Versus Traditional Field Measurements of Fractional Ground Cover in the Australian Arid Zone

2019 ◽  
Vol 11 (23) ◽  
pp. 2825 ◽  
Author(s):  
Claire Fisk ◽  
Kenneth Clarke ◽  
Megan Lewis
Keyword(s):  
Spatial Scale ◽  
Arid Zone ◽  
Ground Cover ◽  
Field Measurements ◽  
Bare Soil ◽  
Point Sampling ◽  
Calibration And Validation ◽  
Fractional Cover ◽  
In Situ Methods

The collection of high-quality field measurements of ground cover is critical for calibration and validation of fractional ground cover maps derived from satellite imagery. Field-based hyperspectral ground cover sampling is a potential alternative to traditional in situ techniques. This study aimed to develop an effective sampling design for spectral ground cover surveys in order to estimate fractional ground cover in the Australian arid zone. To meet this aim, we addressed two key objectives: (1) Determining how spectral surveys and traditional step-point sampling compare when conducted at the same spatial scale and (2) comparing these two methods to current Australian satellite-derived fractional cover products. Across seven arid, sparsely vegetated survey sites, six 500-m transects were established. Ground cover reflectance was recorded taking continuous hyperspectral readings along each transect while step-point surveys were conducted along the same transects. Both measures of ground cover were converted into proportions of photosynthetic vegetation, non-photosynthetic vegetation, and bare soil for each site. Comparisons were made of the proportions of photosynthetic vegetation, non-photosynthetic vegetation, and bare soil derived from both in situ methods as well as MODIS and Landsat fractional cover products. We found strong correlations between fractional cover derived from hyperspectral and step-point sampling conducted at the same spatial scale at our survey sites. Comparison of the in situ measurements and image-derived fractional cover products showed that overall, the Landsat product was strongly related to both in situ methods for non-photosynthetic vegetation and bare soil whereas the MODIS product was strongly correlated with both in situ methods for photosynthetic vegetation. This study demonstrates the potential of the spectral transect method, both in its ability to produce results comparable to the traditional transect measures, but also in its improved objectivity and relative logistic ease. Future efforts should be made to include spectral ground cover sampling as part of Australia’s plan to produce calibration and validation datasets for remotely sensed products.

scholarly journals Relationship between “Dry Weight” and Actual Weight Loss in Patients Hospitalized for Heart Failure

2019 ◽  
Vol 25 (8) ◽  
pp. S51-S52
Author(s):  
J. Fleming ◽  
M. Griffin ◽  
J. Ivey-Miranda ◽  
P. Raghavendra ◽  
G. Struyk ◽  
...  
Keyword(s):  
Heart Failure ◽  
Weight Loss ◽  
Dry Weight ◽  
Actual Weight ◽  
Actual Weight Loss

scholarly journals Land cover transitions and effects of transhumance on available forage biomass of rangelands in Benin

2021 ◽  
Author(s):  
James Ellison ◽  
Katja Brinkmann ◽  
Rodrigue V. Cao Diogo ◽  
Andreas Buerkert
Keyword(s):  
Land Cover ◽  
Land Use Planning ◽  
Vegetation Period ◽  
Landscape Fragmentation ◽  
Population Pressure ◽  
Long Term Effects ◽  
Destructive Sampling ◽  
Herbaceous Biomass ◽  
Forage Availability ◽  
Negative Impacts

AbstractThis study examined the effects of transhumance pressure on total abavoe-ground biomass and forage availability on rangelands in Benin. We also investigated the implications of land cover transitions on rangelands over a 31-year period. Our work was carried out in three regions of Benin representing distinct phytogeographic regimes: Ketou, Tchaourou, and Sinende. Ground-truthing and biomass sampling of the herbaceous and phanaerophyte strata were carried out between the 2016 peak vegetation period and the onset of the 2017 rainy season. Herbaceous biomass was determined by destructive sampling, and biomass of shrub and trees was estimated using non-destructive sampling and allometric equations. Historical and present-day Landsat data allowed an analysis of land cover change for the 1986–2002 and 2002–2017 periods. Land cover analyses yielded evidence of significant expansion of agricultural areas, especially in the latter period. The data also revealed progressive landscape fragmentation and transformations to a land cover of reduced total phytomass. There were no long-term effects of transhumance on trees, but likely on herbaceous biomass. Land cover changes in the study regions seem primarily the result of population pressure, infrastructural changes, persisting norms, and traditions regarding environmental management and the increasing popularity of livestock keeping as an insurance strategy. Rangeland transformations had negative impacts on transhumant herds’ mobility and forage availability. As rangeland stability and consent between agricultural and pastoral land users are at a tipping point, informed policies, and land use planning that foster compromises among all stakeholders are needed.

scholarly journals 407 Nitrogen Retention and Release by Paper Pellets in the Bottom of Nursery Containers

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 463B-463
Author(s):  
J.O. Glenn ◽  
C.H. Gilliam ◽  
J.H. Edwards ◽  
G.J. Keever ◽  
J. Olive ◽  
...  
Keyword(s):  
Nitrogen Retention ◽  
Dry Weight ◽  
Pine Bark ◽  
Destructive Sampling ◽  
Fertilizer Rate ◽  
Recycled Paper ◽  
Total N ◽  
Foliar N ◽  
Shoot Dry Weight ◽  
Nitrate N

Recycled paper pellets in the bottom of containers were evaluated for retention of N from container leachate. `Formosa' azalea were transplanted on 15 Apr. in 2.8-L containers in a pine bark/peat substrate (3:1; v/v). Treatments included paper (0 or 2.5 cm depth) in the bottom of containers and two rates of Osmocote 18–6–12 (0.68 kg or 1.36 kg N/yd3). Immediately after transplanting, plants were topdressed with 3.2 g of 12–4–6 fertilizer. Data collected included leachate samples every 2 weeks for NO3-N and NH4-N levels and destructive sampling every 4 weeks for shoot dry weight, foliar N, and total paper N. Nitrate-N and NH4-N leachate concentrations were reduced with the 0.68 kg N/yd3 fertilizer rate and with paper. For example, 28 days after planting (DAP) NO3-N leachate concentrations were reduced 36% with the 0.68 kg N/yd3 fertilizer rate and 46% with paper in the bottom of containers. NH4-N in the leachates was reduced 53% with the 0.68 kg N/yd3 fertilizer rate and 59% with paper. Azalea shoot dry weight was not affected by paper or fertilizer rate up to 112 DAP; however, as the study progressed, plants with paper in the bottom of containers grew larger than plants in no paper treatments (29% at 168 DAP, 31% at 196 DAP). Total N absorbed by paper was not affected by fertilizer rate, and peaked at 168 DAP [980 (0.68 kg N/yd3) to 1066 (1.36 kg N/yd3) mg per container, or 41% – 28% of applied N], after which it began to decline. This decline in paper N was associated with greater growth of azalea with paper.

scholarly journals Influence of Sowing Date on Growth and Yield Components of Sunflower (Helianthus Annuus L.) in Semi-Arid Zone

2019 ◽  
Vol 2 (2) ◽  
pp. 36-42
Author(s):  
Hilwa, D. Abu Anga ◽  
Wael A. Marajan ◽  
Abu backer H. Mohammed ◽  
Baha Eldin M Idris
Keyword(s):  
Plant Height ◽  
Yield Components ◽  
Arid Zone ◽  
Block Design ◽  
Dry Weight ◽  
Sowing Date ◽  
Growth And Yield ◽  
Area Index ◽  
Head Diameter ◽  
Semi Arid

The main objective of this study was to quantify the influence of sowing date on growth and yield components of hybrid sunflower (Hysun33) cultivar in semi-arid zone. This experiment was conducted during the seasons 2014/2015-2015/2016 at the farm of the College of Agricultural Studies, Sudan University of Science and Technology, Shambat, Khartoum- Sudan. The experiment was arranged in randomized complete block design (RCBD) with four replications and three treatments. Different parameters were considered including plant height, leaf area index (LAI), filled sees number/head, head diameter, dry weight and yield components. The collected data were statistically analyzed. The results revealed that crop sown in May and July showed significant increase in plant height, LAI, head diameter, dry weight, field seed number/head, weight of 100 seeds; yield, and yield; compared to crop sown in March. However, crop sown in the second season showed an increase in growth and yield components compared to the crop of the first season.

Macroinfauna of northern New England marine sand. II. Amphipod-dominated intertidal communities

1975 ◽  
Vol 53 (1) ◽  
pp. 42-51 ◽  
Author(s):  
R. A. Croker ◽  
R. P. Hager ◽  
K. J. Scott
Keyword(s):  
New England ◽  
Atlantic Coast ◽  
Dry Weight ◽  
Amphipod Species ◽  
Species Dominance ◽  
Carbon And Nitrogen ◽  
Marine Sand ◽  
Nitrogen Concentrations ◽  
Northern New England ◽  
Exposed Habitat

This is a 5-year study of macroinfaunal communities of moderately exposed to sheltered intertidal sands of New Hampshire and southwestern Maine. Habitats also differed in slope, width, predominant sand grain size, and carbon–nitrogen concentrations. Thirty-one species were recorded. Abundance and dry weight biomass at four intensively studied habitats averaged 5000/m2 and 2.1 g/m2, respectively, during 1971. The most exposed habitat yielded twice this standing crop, correlated with intermediate levels of carbon and nitrogen. Over 90% of seasonal numbers and biomass at more exposed habitats were attributable to six species of relatively short-lived amphipods, mostly Haustoriidae. Between-habit at variation in abundance and biomass of amphipods was in general greater than seasonal variation within habitats. Polychaete species increased at sheltered habitats, and bivalve mollusks were restricted to shelter. The typical community of moderately exposed sands south of Penobscot Bay, Maine, is characterized by a recurrent group of nine species (five amphipods). Community stability is assisted by brooding habits of dominant amphipods. Zonation, subtidal connections, seasonal movements, and patterns of amphipod species dominance are discussed. Structural comparisons are made with boreal European and other Atlantic coast intertidal sand communities.

scholarly journals The Effects of Black and White Plastic Mulch on Soil Temperature and Yield of Crisphead Lettuce in Southern New England

2020 ◽  
Vol 30 (6) ◽  
pp. 781-788
Author(s):  
Rahmatallah Gheshm ◽  
Rebecca Nelson Brown
Keyword(s):  
New England ◽  
Soil Temperature ◽  
Rank Order ◽  
Bare Ground ◽  
Plastic Mulch ◽  
Black And White ◽  
Southern New England ◽  
Soil Temperatures ◽  
Head Height ◽  
Canopy Size

Annually, Americans consume an average of 24.5 lb of lettuce (Lactuca sativa) per capita, more than half of which is head lettuce. This study examined the impacts of using black and white-on-black polyethylene mulches on three crisphead lettuce cultivars for spring production in the open field, with data collected on the soil temperature and lettuce yields. Black polyethylene, white-on-black polyethylene, and bare ground were compared for effects on soil temperature, lettuce yields, and lettuce head height and diameter. Mean soil temperatures at a 5 cm depth were 18.9 °C under black polyethylene, 17.7 °C under white-on-black polyethylene, and 17.1 °C in bare ground plots. Changes in the lettuce canopy size presented a similar trend over the growing season in all treatments. Both mulch type and cultivar significantly (P < 0.01) affected the canopy growth in head lettuce. Lettuce on black polyethylene mulch grew significantly (P < 0.01) faster than lettuce on white-on-black polyethylene or bare ground. However, the black and white-on-black mulches produced similar yields, averaging 5.76 and 5.71 kg·mˉ2, respectively. Meanwhile, bare ground plot yields were significantly (P < 0.01) lower at 4.57 kg·mˉ2. Cultivar rank order was consistent across treatments, and Crispino and Garmsir at 5.82 and 5.47 kg·mˉ2 fresh weight had significantly higher yields than Nevada at 4.75 kg·mˉ2 (P < 0.01).

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