scholarly journals Tree Biomass Estimation in Karst Forest of West Papua, Indonesia

Jurnal Wasian ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 75-86
Author(s):  
Andes Rozak ◽  
◽  
Destri Destri ◽  
Zaenal Mutaqien

Indonesia is estimated to have 14,5 million hectares of karst areas. The characteristic of karst vegetation is specific, one of which is the dominance of small trees. With all of the potency, their vegetation acts as a significant carbon sequester and store it in biomass. This study aims to estimate and discuss biomass estimation in the karst forest within the Nature Recreational Park of Beriat, a protected area in South Sorong, West Papua. A total of 28 plots were made in the forest using the purposive random sampling method. Tree biomass (DBH ≥10 cm) was estimated using five different allometric equations. The results showed that the biomass was estimated at ca. 264 Mg ha-1 (95 % CI: 135-454 Mg ha-1). While small trees (DBH 10 – 30 cm) only contribute 30 % of the total biomass, about 38 % of the biomass is the contribution of large trees (DBH >50 cm), where Pometia pinnata contributes ca. 39 % of the biomass at plot-level. The use of various allometric equations results in different biomass estimates and biases with deviations ranged from -14.78 % to +17.02 % compared to the reference equation. Therefore, the selection of allometric equations used must be considered carefully to reduce uncertainties in biomass estimation.

2017 ◽  
Vol 11 (1) ◽  
pp. 85
Author(s):  
Andes Hamuraby Rozak ◽  
Sri Astutik ◽  
Zaenal Mutaqien ◽  
Didik Widyatmoko ◽  
Endah Sulistyawati

Hiperdominansi jenis dan biomassa adalah suatu konsep yang menjelaskan pentingnya sebagian kecil jenis dan biomassa relatif terhadap rata-rata biomassa pohon pada suatu kawasan hutan. Pemahaman pada konsep ini berimplikasi pada upaya monitoring kawasan hutan khususnya bagi spesies penyumbang biomassa terbesar dan membantu pemahaman pada proses restorasi ekologinya. Analisis hiperdominansi jenis dan kontribusi pohon besar (DBH>50 cm) terhadap biomassa pohon telah dilakukan di kawasan hutan Taman Nasional Gunung Gede Pangrango (TNGGP). Sejumlah 26 plot pengamatan telah dibuat pada 26 level ketinggian yang berbeda (1013-3010 m dpl) dan dikelompokkan menjadi tiga zona yaitu zona submontana, montana, dan subalpine. Pohon-pohon yang terdapat dalam plot pengamatan kemudian dikelompokkan menjadi 3 kelompok diameter yaitu pohon kecil (5-30 cm), pohon sedang (30-50 cm), dan pohon besar (>50 cm). Hasil analisis menunjukkan bahwa hiperdominansi jenis terjadi di hutan TNGGP. Empat jenis pohon dari 114 jenis yang teridentifikasi yaitu Schima wallichii, Altingia excelsa, Vaccinium varingiaefolium, dan Castanopsis acuminatissima merepresentasikan 56,96% dari total biomassa pohon yang ada di plot TNGGP. Lebih lanjut, pohon kecil dan besar diketahui sebagai penyumbang biomassa yang sangat signifikan dibandingkan pohon sedang. Pada level plot penelitian, pohon dengan DBH>50 cm yang berjumlah 192 individu (atau 13%) dari 1471 individu pohon mampu merepresentasikan 61,4% dari total biomassanya. Namun demikian, pada level kawasan hutan, pohon kecil dan pohon besar memiliki kontribusi yang sama signifikannya terhadap biomassa per hektarnya yaitu masing-masing sebesar 40,9% dan 38,77%. Hasil-hasil tersebut menunjukkan bahwa hanya sedikit jenis pohon saja mampu merepresentasikan sebagian besar dari total biomassa pohon. Pohon-pohon kecil dan besar diketahui memainkan peranan yang penting dalam biomassa di hutan TNGGP.Hyperdominance of Tree Species and Biomass in Mount Gede Pangrango National Park, IndonesiaAbstractThe hyperdominance of tree species and biomass is a concept explaining the importance of a small portion of species and biomass relative to the average of biomass in a forested area. Understanding this concept has important implication on forest monitoring, especially to monitor the most significant species that show high contributes on biomass and its ecological restoration. Hyperdominance analysis of tree species and large trees (DBH > 50 cm) contribution to tree biomass were investigated in tropical mountain forest of Mount Gede Pangrango National Park (TNGGP). A total of 26 sample plots were installed in 26 different altitude between 1013 and 3010 m asl and grouped into three zones i.e. submontane, montane, and subalpine zones. Trees within plot were identified, measured, and grouped into three groups i.e. small (DBH 5-30 cm), medium (DBH 30-50 cm), and large trees (DBH>50 cm). The result showed that there were hyperdominant in TNGGP. Four species from 114 identified tree species i.e. Schima wallichii, Altingia excelsa, Vaccinium varingiaefolium, and Castanopsis acuminatissima represented 56.96% of the total biomass in the plot level. Furthermore, only 13% of trees from 1471 trees responsible for 61.4% of the total tree biomass in the plot level. However, small and large trees have similar significant contribution to the average biomass in the forest level i.e. 40.9% and 38.77%, respectively. These results suggest that only few species represent a huge amount of biomass. Both small and large trees play important role in the forest biomass of TNGGP.


2016 ◽  
Vol 46 (4) ◽  
pp. 485-498 ◽  
Author(s):  
Olivier Blarquez ◽  
Julie C. Aleman

Forest ecosystems in eastern Canada are particularly sensitive to climate change and may shift from carbon sinks to carbon sources in the coming decades. Understanding how forest biomass responded to past climate change is thus of crucial interest, but past biomass reconstruction still represents a challenge. Here we used transfer functions based on modern pollen assemblages and remotely sensed biomass estimation to reconstruct and quantify, for the last 14 000 years, tree biomass dynamics for the six main tree genera of the boreal and mixedwood forests (Abies, Acer, Betula, Picea, Pinus, Populus). We compared the mean genera and total biomass with climatic (summer temperatures and annual precipitation), physical (CO2, insolation, ice area), and disturbance (burned biomass) variables to identify the potential drivers influencing the long-term trends in tree biomass. For most genera, tree biomass was related to summer temperature, insolation, and CO2 levels; Picea was the exception and its biomass also correlated with annual precipitation. At the onset of the Holocene and during the Holocene Thermal Maximum (ca. 10 000–6000 BP), tree biomass tracked the melting of the Laurentide Ice Sheet with high values (>50 tonnes·ha–1 and a total of 12 Pg). These values, in the range of modern forest ecosystems biomass, indicate that trees were probably able to survive in a periglacial environment and to colonize the region without any discernible lag by tracking the ice retreat. High biomass at the beginning of the Holocene was likely favoured by higher than present insolation, CO2 levels higher than during the Last Glacial Maximum, and temperature and precipitation close to present-day levels. Past tree biomass reconstruction thus brings novel insights about the drivers of postglacial tree biomass and the overall biogeography of the region since the deglaciation.


2011 ◽  
Vol 59 (7) ◽  
pp. 640 ◽  
Author(s):  
J. H. Jonson ◽  
D. Freudenberger

In the south-western region of Australia, allometric relationships between tree dimensional measurements and total tree biomass were developed for estimating carbon sequestered in native eucalypt woodlands. A total of 71 trees representing eight local native species from three genera were destructively sampled. Within this sample set, below ground measurements were included for 51 trees, enabling the development of allometric equations for total biomass applicable to small, medium, and large native trees. A diversity of tree dimensions were recorded and regressed against biomass, including stem diameter at 130 cm (DBH), stem diameter at ground level, stem diameter at 10 cm, stem diameter at 30 cm, total tree height, height of canopy break and mean canopy diameter. DBH was consistently highly correlated with above ground, below ground and total biomass. However, measurements of stem diameters at 0, 10 and 30 cm, and mean canopy diameter often displayed equivalent and at times greater correlation with tree biomass. Multi-species allometric equations were also developed, including ‘Mallee growth form’ and ‘all-eucalypt’ regressions. These equations were then applied to field inventory data collected from three locally dominant woodland types and eucalypt dominated environmental plantings to create robust relationships between biomass and stand basal area. This study contributes the predictive equations required to accurately quantify the carbon sequestered in native woodland ecosystems in the low rainfall region of south-western Australia.


2020 ◽  
Author(s):  
Getaneh Gebeyehu ◽  
Teshome Soromessa ◽  
Tesfaye Bekele ◽  
Demel Teketay

Abstract Background: Tree species based developing allometric equations are important because they contain the largest proportion of total biomass and carbon stocks of forests. Studies on developing and validating the species-specific allometric models (SSAM) remain insufficient that may result to biomass estimation errors in the forests. The purpose of this study is to determine the wood density of four tree species and develop and validate the accuracy of allometry for biomass estimations. A total of 103 sample trees representing four species were harvested semi-destructively. The species specific allometric equations (SSAM) were developed using aboveground biomass (AGB in kg) as dependent variable, and three of the predictor’s variables: diameter at beast height (DBH in cm), height (H in m) and wood density (WD in g cm-3). The relation between dependent and independent variables were tested using multiple correlations (R2). The model selection and validation was based on statistical significance of model parameter estimates, Akaike Information Criterion (AIC), adjusted coefficient of determination (R2), residual standard error (RSE) and mean relative error (MRE). Results: The results showed that the AGB correlated significantly with diameter at breast height (R2 > 0.944, P < 0.001), and tree height (R2 > 0.742, P <0.001). The species-specific allometric models, which include DBH, H and WD predicted AGB with high-model fit (R2 > 93.6%, P < 0.001). These models for biomass estimations produced small MRE (1.50–3.40%) and AIC (-7.04 –12.84) compared to a single predictor (MRE:-0.4 – 20.1%; AIC: -7.25 – 35.29). The SSAM also predicted AGB against predictors with high-model fit (R2 > 93.6%, P < 0.001) and small MRE: 1.50 – 3.40% compared to existing general allometric models (MRE: - 31.3 – 11.31%). Conclusions: The research confirmed that the inclusion of DBH, H, and WD in the SSAM predicted AGB with small bias than a single or two predictors. The wood density values of those studied species can be used as the references for biomass estimations using general allometric equations. The study contributes to species-specific allometric models for understanding the total biomass estimation of species. Therefore, the application of species-specific allometric models should be considered in biomass estimations of forests.


Author(s):  
I.V. TORBINA ◽  
◽  
I.R. FARDEYEVA ◽  

The paper assesses the promising varieties of winter wheat in a competitive variety test by the main economic and biological characteristics that determine the suitability of the variety for commercial use. The object of research was the authors’ own breeding material. The experiments on the selection of winter wheat were made in the experimental crop rotation pattern of the Institute.


Author(s):  
John Hunsley ◽  
Eric J. Mash

Evidence-based assessment relies on research and theory to inform the selection of constructs to be assessed for a specific assessment purpose, the methods and measures to be used in the assessment, and the manner in which the assessment process unfolds. An evidence-based approach to clinical assessment necessitates the recognition that, even when evidence-based instruments are used, the assessment process is a decision-making task in which hypotheses must be iteratively formulated and tested. In this chapter, we review (a) the progress that has been made in developing an evidence-based approach to clinical assessment in the past decade and (b) the many challenges that lie ahead if clinical assessment is to be truly evidence-based.


2016 ◽  
Vol 04 (03) ◽  
pp. 156-164
Author(s):  
Deepak Bansal ◽  
Shruti Sharma ◽  
Manjit Kumar ◽  
Amrit Khosla

AbstractAn altered facial appearance is more difficult to face, than problems related to ill-fitting denture or eating. The selection of maxillary anterior teeth for complete denture has long posed problem in clinical practice and a controversy about the best method to employ still exists. An attempt is made in the present study to clinically correlate the face form with maxillary central incisor tooth form in males and females of Davangere population. In 1914, Leon William's projected the “the form method” where he classified facial forms as square, tapering, and ovoid. Maxillary central incisors were selected according to the facial forms.Of total 100 subjects four different tooth forms and face forms were evaluated. They are: square, ovoid, square-tapered, tapered. No significant correlation existed between face form in male and females. Females exhibited greater correlation between face forms and inverted tooth form but that correlation is not sufficient to serve as a guide for selection of anterior teeth.


Author(s):  
Andre D. L. Batako ◽  
Valery V. Kuzin ◽  
Brian Rowe

High Efficiency Deep Grinding (HEDG) has been known to secure high removal rates in grinding processes at high wheel speed, relatively large depth of cut and moderately high work speed. High removal rates in HEDG are associated with very efficient grinding and secure very low specific energy comparable to conventional cutting processes. Though there exist HEDG-enabled machine tools, the wide spread of HEDG has been very limited due to the requirement for the machine tool and process design to ensure workpiece surface integrity. HEDG is an aggressive machining process that requires an adequate selection of grinding parameters in order to be successful within a given machine tool and workpiece configuration. This paper presents progress made in the development of a specialised HEDG machine. Results of HEDG processes obtained from the designed machine tool are presented to illustrate achievable high specific removal rates. Specific grinding energies are shown alongside with measured contact arc temperatures. An enhanced single-pole thermocouple technique was used to measure the actual contact temperatures in deep cutting. The performance of conventional wheels is depicted together with the performance of a CBN wheel obtained from actual industrial tests.


2014 ◽  
Vol 10 ◽  
pp. 2858-2873 ◽  
Author(s):  
Robert Francke

Due to the fact that the major portion of pharmaceuticals and agrochemicals contains heterocyclic units and since the overall number of commercially used heterocyclic compounds is steadily growing, heterocyclic chemistry remains in the focus of the synthetic community. Enormous efforts have been made in the last decades in order to render the production of such compounds more selective and efficient. However, most of the conventional methods for the construction of heterocyclic cores still involve the use of strong acids or bases, the operation at elevated temperatures and/or the use of expensive catalysts and reagents. In this regard, electrosynthesis can provide a milder and more environmentally benign alternative. In fact, numerous examples for the electrochemical construction of heterocycles have been reported in recent years. These cases demonstrate that ring formation can be achieved efficiently under ambient conditions without the use of additional reagents. In order to account for the recent developments in this field, a selection of representative reactions is presented and discussed in this review.


2012 ◽  
Vol 9 (8) ◽  
pp. 3381-3403 ◽  
Author(s):  
T. R. Feldpausch ◽  
J. Lloyd ◽  
S. L. Lewis ◽  
R. J. W. Brienen ◽  
M. Gloor ◽  
...  

Abstract. Aboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer the following questions: 1. What is the best H-model form and geographic unit to include in biomass models to minimise site-level uncertainty in estimates of destructive biomass? 2. To what extent does including H estimates derived in (1) reduce uncertainty in biomass estimates across all 327 plots? 3. What effect does accounting for H have on plot- and continental-scale forest biomass estimates? The mean relative error in biomass estimates of destructively harvested trees when including H (mean 0.06), was half that when excluding H (mean 0.13). Power- and Weibull-H models provided the greatest reduction in uncertainty, with regional Weibull-H models preferred because they reduce uncertainty in smaller-diameter classes (≤40 cm D) that store about one-third of biomass per hectare in most forests. Propagating the relationships from destructively harvested tree biomass to each of the 327 plots from across the tropics shows that including H reduces errors from 41.8 Mg ha−1 (range 6.6 to 112.4) to 8.0 Mg ha−1 (−2.5 to 23.0). For all plots, aboveground live biomass was −52.2 Mg ha−1 (−82.0 to −20.3 bootstrapped 95% CI), or 13%, lower when including H estimates, with the greatest relative reductions in estimated biomass in forests of the Brazilian Shield, east Africa, and Australia, and relatively little change in the Guiana Shield, central Africa and southeast Asia. Appreciably different stand structure was observed among regions across the tropical continents, with some storing significantly more biomass in small diameter stems, which affects selection of the best height models to reduce uncertainty and biomass reductions due to H. After accounting for variation in H, total biomass per hectare is greatest in Australia, the Guiana Shield, Asia, central and east Africa, and lowest in east-central Amazonia, W. Africa, W. Amazonia, and the Brazilian Shield (descending order). Thus, if tropical forests span 1668 million km2 and store 285 Pg C (estimate including H), then applying our regional relationships implies that carbon storage is overestimated by 35 Pg C (31–39 bootstrapped 95% CI) if H is ignored, assuming that the sampled plots are an unbiased statistical representation of all tropical forest in terms of biomass and height factors. Our results show that tree H is an important allometric factor that needs to be included in future forest biomass estimates to reduce error in estimates of tropical carbon stocks and emissions due to deforestation.


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