scholarly journals Developing Additive Systems of Biomass Equations for Robinia pseudoacacia L. in the Region of Loess Plateau of Western Shanxi Province, China

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1332
Author(s):  
Yanhong Cui ◽  
Huaxing Bi ◽  
Shuqin Liu ◽  
Guirong Hou ◽  
Ning Wang ◽  
...  

The accurate estimation of forest biomass is important to evaluate the structure and function of forest ecosystems, estimate carbon sinks in forests, and study matter cycle, energy flow, and the effects of climate change on forest ecosystems. Biomass additivity is a desirable characteristic to predict each component and the total biomass since it ensures consistency between the sum of the predicted values of components such as roots, stems, leaves, pods, and branches and the prediction for the total tree. In this study, 45 Robinia pseudoacacia L. trees were harvested to determine each component and the total biomass in the Loess Plateau of western Shanxi Province, China. Three additive systems of biomass equations of R. pseudoacacia L., based on the diameter at breast height (D) only and on the combination of D and tree height (H) with D2H and DbHc, were established. To ensure biomass model additivity, the additive system of biomass equations considers the correlation among different components using simultaneous equations and establishes constraints on the parameters of the equation. Seemingly uncorrelated regression (SUR) was used to estimate the parameters of the additive system of biomass equations, and the jackknifing technique was used to verify the accuracy of prediction of the additive system of biomass equations. The results showed that (1) the stem biomass contributed the most to the total biomass, comprising 51.82% of the total biomass, followed by the root biomass (24.63%) and by the pod and leaf biomass, which accounted for the smallest share, comprising 1.82% and 2.22%, respectively; (2) the three additive systems of biomass equations of R. pseudoacacia L. fit well with the models and were effective at making predictions, particularly for the root, stem, above-ground, and total biomass (R2adj > 0.812; root mean square error (RMSE) < 0.151). The mean absolute error (MAE) was less than 0.124, and the mean prediction error (MPE) was less than 0.037. (3) When the biomass model added the tree height predictor, the goodness of fit R2adj increased, RMSE decreased, and the accuracy of prediction was much improved. In particular, the additive system, which was developed based on DbHc combination prediction factors, was the most accurate. The additive system of biomass equations established in this study can provide a reliable and accurate estimation of the individual biomass of R. pseudoacacia L. in the Loess region of western Shanxi Province, China.

2018 ◽  
Vol 64 (No. 2) ◽  
pp. 96-100 ◽  
Author(s):  
Rédei Károly ◽  
Bakti Beatrix ◽  
Kiss Tamás ◽  
Takács Marianna ◽  
Keserű Zsolt

The paper provides the results of a detailed analysis of timber volume and the most important crown variables of black locust (Robinia pseudoacacia Linnaeus) based on an experimental plot in southern Hungary. At the age of 20 years the crop trees belonged to different height classes. If the volume of the mean tree from height class I is considered as 100%, the volume of the mean tree of class II is 44.0%, and the mean tree of class III is only 30.3%. In case of timber volume per 1 m<sup>2</sup> crown surface, the values are 72.9 and 61.7%. The DBH of trees showed a positive linear correlation with crown diameter (r = 0.942). Additionally, there were also positive linear relationships between crown diameter and volume (r = 0.901), between crown length and volume (r = 0.721) as well as tree height and crown length (r = 0.661). The variation of crown indices is height even within the same stand and indicates the importance of following a selective thinning operation method.


2014 ◽  
pp. 9-31
Author(s):  
Sinisa Andrasev ◽  
Savo Roncevic ◽  
Petar Ivanisevic ◽  
Sasa Pekec ◽  
Martin Bobinac

This paper presents the elements of growth of black locust trees and stands in 15 sample plots in Vojvodina, at the age of 21-68 years. In each sample plot, based on soil profile horizons the determined soil type was chernozem as well as its lower systematic units (subtype, variety and form), according to the Skoric et al. (1985) classification. On the basis of the mean stand heights (hL), the stands on the subtype of chernozem on loess and loesslike sediments belong to height classes I-IV, and stands on calcareous aeolian sand to classes II-V (according to R e d e i et al. 2014), which indicates their considerable variability with respect to productivity within the determined subtypes of chernozem. Significant differences at the level of chernozem subtypes were found between the mean heights (p = 0.032), but not between the mean diameters (p = 0.083). The mean diameters at breast height in the studied black locust stands were on average lower than the models of diameter growth for the appropriate height classes and determined by a larger number of trees per hectare than in the tables (R e d e i et al, 2014). The volume per hectare is higher than in the tables also being conditioned by the large number of trees per hectare.


Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 470
Author(s):  
Artur Kraszkiewicz

This study investigated growth performances of black locust (Robinia pseudoacacia L.) tree species in various soil and agro-climatic conditions in Poland. Implementing of research was based on monoculture black locust stands in which it was possible to carry out dendrometric tests allowing us to learn about their volume. These stands were located on marginal soils. In the sample plots selected for the study, the parameters of stands (main and secondary) were determined, such as number and social structure of trees, average tree height, average diameter at breast height (DBH), and volume. The volume was determined with division into trunks and branches and wood thickness classes (0.0–1.0 cm, 1.1–5.0 cm, 5.1–10.0 cm and then every 5 cm). During the research, it was found that sunlight and moisture conditions mainly affect the volume. It has been noticed that the content of nutrients in the soil plays a minor role because black locust grows very well in poorly fertile soils, often subject to erosion processes. Black locust grows well on damp, shaded slopes with northern exposures. In such areas, the stand volume was the highest (353.8 m3×ha−1), exceeding the average volume of the remaining 35-year-old stands on sandy soils by 60%. Along with the increase in the age of stands, the share of trunk wood increased with the wood of branches. The share of wood up to 5.0 cm was small in older stands, at most a dozen or so percent. However, in young stands (4- and 8-year-old), the share of the thickness class up to 5 cm was even 65% of the stand volume. In 35-year-old stands, wood fractions of 15.1–20.0 cm were dominant. In the oldest, 64-year-old stand, over 30 cm thick wood constituted 44% of the stand volume. However, statistical analysis showed, with p = 0.1644, no differences existed between the thickness of the individual thickness classes.


2016 ◽  
Vol 140 (11-12) ◽  
pp. 567-576 ◽  
Author(s):  
Turan Sönmez ◽  
Mehmet Yavuz ◽  
Abdurrahman Şahin ◽  
Aydin Karhiman

The aim of this study was to develop allometric equations for the estimation of above-ground biomass components of Calabrian pine (Pinus brutia Ten.) tree in the Mediterranean Region of Turkey. Using regression analysis, different allometric equations were fitted for the tree components of the above-ground biomass using diameter at breast height (dbh) and tree height as estimators. Two hundred and ninety-two trees between 0.4 and 63.0 cm in dbh were randomly sampled throughout 292 natural, pure Calabrian pine stands in Turkey’s Mediterranean Region, where it forms diverse stand structures. Finally, the allometric equations were developed for the tree components of the Calabrian pine tree for the stem, bark, branch, needle and total above-ground biomass. The stem, bark and total biomass equations explained more than 90% of the observed variability, while the branch and needle biomass equations explained 82% and 65%, respectively.


2017 ◽  
Vol 23 (1-4) ◽  
Author(s):  
Zs. Keserü ◽  
I. Csiha ◽  
B. Bakti ◽  
K. Rédei

Black locust (Robinia pseudoacacia L.) can be considered as one of the most suitable tree species for establishing energy plantations due to its favourable growing characteristics such as vigorous growing potential in the juvenile phase, excellent coppicing ability, a relatively high resistance to pests. Based on national and international test results the mean annual increment of oven-dry weight of energy plantations regenerated by coppicing generally exceeds the first cycle plantations established by seedlings.


2020 ◽  
Vol 12 (4) ◽  
pp. 940-958
Author(s):  
Andrea M. ROMAN ◽  
Irina M. MORAR ◽  
Alina M. TRUȚA ◽  
Cătălina DAN ◽  
Adriana F. SESTRAȘ ◽  
...  

Black locust (Robinia pseudoacacia L.) was among the first North-American tree species imported in Europe. In Romania, black locust has established itself as a forest tree appreciated for multiple uses. The objective of the hereby study was to identify a quality planting material at black locust using seeds from trees with superior traits from five stands geographically close, located in North-western of Romania. An empirical selection was done, thus trees with the most favourable traits were selected as plus trees. Among the averages of the main traits (tree height, diameter at breast height, basal area, self pruning trunk length, crown diameter) of the plus trees from the five stands, there were registered significant differences, and two stands stood out with a high biomass growth. Even if the stands had different ages (between 20-35 year), the age did not influence significantly the growth traits of the trees. The seeds of the plus trees (open-pollinated) from all the stands had large size (mean seed weight of 0.057 g/seed). The seedling emergence rate was high, especially in the solarium condition (between 52.7-73.7% compared with 33.0-41.3% in the field). Coefficient of genetic correlation and heritability calculated for the seedlings belongings to half-sib families highlighted that black locust breeding can be extremely effective by a proper selection.


Pneumologie ◽  
2004 ◽  
Vol 58 (11) ◽  
Author(s):  
S Kespohl ◽  
R Merget ◽  
M Gellert ◽  
T Brüning ◽  
M Raulf-Heimsoth

Author(s):  
V.V. Tanyukevich ◽  
◽  
S.V. Tyurin ◽  
D.V. Khmeleva ◽  
A.A. Kvasha ◽  
...  

Works on protective afforestation are carried out in order to protect agricultural land from degradation processes, as well as to improve the microclimate of land. The research purpose is to study the bioproductivity and environmental role of Robinia pseudoacacia L. forest shelterbelts in the conditions of the Kuban lowland. The approved and generally accepted methods of forest valuation, forest land reclamation, botany, and mathematical statistics were applied. Plantings were created according to the standard technology for the steppe zone of the Russian Federation. The area of forest shelterbelts is 62.4 ths ha, including 5 % of the young growth (I state class), 80 % of middle-aged forest plantings (II state class), 10 % of maturing plantings (II state class), 5 % of mature and overmature plantings (III state class). Living ground cover is formed by the following species: Koeleria pyramidata L., Poa pratensis L., Festuca pratensis H., Elytrígia repens L., Dactylis glomerata L., and Phlum pratense L. Aboveground phytomass is 100–300 g/m2; height is 25–32 cm. Plantings are characterized by the quality classes: young growth – I and II; middle-aged and maturing – III; mature and overmature – IV. At the age of natural maturity (70 years), the Robinia trunk reaches the average height of 15.1 m with the average diameter of 22.1 cm. The total stock of wood reaches 18, (ths m3), including (ths m3): young growth – 68 (ths m3); middleaged plantings – 14,871 (ths m3); maturing plantings – 2,187 (ths m3); mature and overmature plantings – 1,314 (ths m3). Aboveground phytomass in young growth is 20.2 t/ha; in mature and overmature plantings it is 391.2 t/ha. In the region it is estimated at 17,070 ths t, including (ths t): young growth – 64; middle-aged plantings – 13,753; maturing plantings – 2,032; mature and overmature plantings – 1,221. The share of stem mass reaches 84.5–80.8 %; woody greenery – 4.2–1.5 %; branches – 11.3–17.7 %. Recalculation coefficients of the stock into aboveground phytomass are the following for: young growth – 0.936; mature and overmature forest shelterbelts – 0.929. Phytosaturation of forest shelterbelts varies within 0.314–2.474 kg/m3. Forest shelterbelts have accumulated 8,534 ths t of carbon, which is estimated at 145.1 mln dollars. The sphere of application of the research results is the Krasnodar Krai forestry, which is recommended to create an additional 60 ths ha of forest shelterbelts, which will provide a normative protective forest cover of arable land of 5 % and annual carbon sequestration up to 3.4 t/ha.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
C Quercioli ◽  
G A Carta ◽  
G Cevenini ◽  
G Messina ◽  
N Nante ◽  
...  

Abstract Background Careful scheduling of elective surgery Operating Rooms (ORs) is crucial for their efficient use, to avoid low/over utilization and staff overtime. Accurate estimation of procedures duration is essential to improve ORs scheduling. Therefore analysis of historical data about surgical times is fundamental to ORs management. We analyzed the effect, in a real setting, of an ORs scheduling model based on estimated optimum surgical time in improving ORs efficiency and decreasing the risk of overtime. Methods We studied all the 2014-2019 elective surgery sessions (3,758 sessions, 12,449 interventions) of a district general hospital in Siena's Province, Italy. The hospital had3 ORs open 5 days/week 08:00-14:00. Surgery specialties were general surgery, orthopedics, gynecology and urology. Based on a pilot study conducted in 2016, which estimated a 5 times greater risk of having an OR overtime for sessions with a surgical time (incision-suture)&gt;200 minutes, from 2017 all the ORs were scheduled using a maximum surgical time of 200 minutes calculated summing the mean surgical times for intervention and surgeon (obtained from 2014-2016 data). We carried out multivariate logistic regression to calculate the probability of ORs overtime (of 15 and 30 minutes) for the periods 2014-2016 and 2017-2019adjusting for raw ORs utilization. Results The 2017-2019 risk of an OR overtime of 15 minutes decreased by 25% compared to the 2014-2016 period (OR = 0.75, 95%CI=0.618-0.902, p = 0.003); the risk of a OR overtime of 30 minutes decreased by 33% (OR = 0.67, 95%CI= 0.543-0.831, p &lt; 0.001). Mean raw OR utilization increase from 62% to 66% (p &lt; 0.001). Mean number of interventions per surgery sessions increased from 3.1 to 3.5 (p &lt; 0.001). Conclusions This study has shown that an analysis of historical data and an estimate of the optimal surgical time per surgical session could be helpful to avoid both a low and excessive use of the ORs and therefore to increase the efficiency of the ORs. Key messages An accurate analysis of surgical procedures duration is crucial to optimize operating room utilization. A data-based approach can improve OR management efficiency without extra resources.


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