Estimation of above-ground biomass in naturally occurring populations of Prosopis pallida (H. & B. ex. Willd.) H.B.K. in the north of Peru

2004 ◽  
Vol 56 (2) ◽  
pp. 283-292 ◽  
Author(s):  
Eva Padrón ◽  
Rafael M Navarro
2001 ◽  
Vol 77 (2) ◽  
pp. 245-253 ◽  
Author(s):  
Don E. Riemenschneider ◽  
J. G. Isebrands ◽  
William E. Berguson ◽  
Donald I. Dickmann ◽  
Richard B. Hall ◽  
...  

We present results from a Populus Regional Testing Program that has been conducted in Minnesota, Iowa, Wisconsin, and Michigan over the past six years. Our objectives have been to: 1) identify highly productive, disease resistant intra- and inter-specific clonal selections and 2) understand patterns of genotype × environment interactions within the region that would, logically, govern commercial deployment of new clones. Clones were developed by breeding and selection programs at the University of Illinois, Iowa State University, University of Minnesota, and the USDA Forest Service for experiments established in 1995. We report results of analyses of variance and principal component analyses of tree diameters and estimated above-ground biomass that demonstrate significant genotype main effects and significant genotype × environment interactions. Maximum mean annual above-ground biomass increments have surpassed 16 Mg ha−1 y−1, exceeding previously reported yields of poplars grown under similar conditions in the north-central U.S. We also discuss the breeding and selection of poplars in general with specific attention to regional research needs. Key words: Populus, biomass, multi-trait selection, genotype, genotype × environment interaction


2018 ◽  
Vol 13 (3) ◽  
pp. 035002 ◽  
Author(s):  
Logan T Berner ◽  
Patrick Jantz ◽  
Ken D Tape ◽  
Scott J Goetz

CERNE ◽  
2010 ◽  
Vol 16 (3) ◽  
pp. 323-334
Author(s):  
Saulo Jorge Téo ◽  
Sebastião do Amaral Machado ◽  
Afonso Figueiredo Filho ◽  
Carlos Bruno Reissmann

The aim of this work was to adjust and test different statistical models for estimating macronutrient content in the above-ground biomass of bracatinga (Mimosa scabrella Bentham). The data were collected from 25 bracatinga trees, all native to the north of the metropolitan region of Curitiba, Paraná state, Brazil. To determine the biomass and macronutrient content, the trees were separated into the compartments leaves, branches < 4 cm, branches > 4 cm, wood and stem barks. Different statistical models were adjusted to estimate N, P, K, Ca and Mg contents in the tree compartments, using dendrometric variables as the model independent variables. Based on the results, the equations developed for estimating macronutrient contents were, in general, satisfactory. The most accurate estimates were obtained for the stem biomass compartments and the sum of the biomass compartments. In some cases, the equations had a better performance when crown and stem dimensions, age and dominant height were included as independent variables.


1997 ◽  
Vol 45 (6) ◽  
pp. 1023 ◽  
Author(s):  
B. F. Clough ◽  
P. Dixon ◽  
O. Dalhaus

A procedure is described for obtaining allometric relationships between stem diameter and above-ground biomass for multi-stemmed trees of the mangroves Rhizophora stylosa and Avicennia marina. The procedure treats each stem as discrete tree that shares a proportion of the butt and other elements common to all stems. Linear log–log relationships were obtained between stem diameter and the dry weights of each above-ground component. Allometric relationships between stem diameter and total above-ground biomass were similar to those for single-stemmed trees in north-eastern Australia, but multi-stemmed trees on the west coast had much greater proportion of their biomass in the form of prop roots than single-stemmed trees of comparable stem diameter on the north-eastern coast. This is attributed to the arid environment on the north-western coast of Australia.


2017 ◽  
Vol 23 (2) ◽  
Author(s):  
AFSHAN ANJUM BABA ◽  
SYED NASEEM UL-ZAFAR GEELANI ◽  
ISHRAT SALEEM ◽  
MOHIT HUSAIN ◽  
PERVEZ AHMAD KHAN ◽  
...  

The plant biomass for protected areas was maximum in summer (1221.56 g/m2) and minimum in winter (290.62 g/m2) as against grazed areas having maximum value 590.81 g/m2 in autumn and minimum 183.75 g/m2 in winter. Study revealed that at Protected site (Kanidajan) the above ground biomass ranged was from a minimum (1.11 t ha-1) in the spring season to a maximum (4.58 t ha-1) in the summer season while at Grazed site (Yousmarag), the aboveground biomass varied from a minimum (0.54 t ha-1) in the spring season to a maximum of 1.48 t ha-1 in summer seasonandat Seed sown site (Badipora), the lowest value of aboveground biomass obtained was 4.46 t ha-1 in spring while as the highest (7.98 t ha-1) was obtained in summer.


2016 ◽  
Vol 13 (11) ◽  
pp. 3343-3357 ◽  
Author(s):  
Zun Yin ◽  
Stefan C. Dekker ◽  
Bart J. J. M. van den Hurk ◽  
Henk A. Dijkstra

Abstract. Observed bimodal distributions of woody cover in western Africa provide evidence that alternative ecosystem states may exist under the same precipitation regimes. In this study, we show that bimodality can also be observed in mean annual shortwave radiation and above-ground biomass, which might closely relate to woody cover due to vegetation–climate interactions. Thus we expect that use of radiation and above-ground biomass enables us to distinguish the two modes of woody cover. However, through conditional histogram analysis, we find that the bimodality of woody cover still can exist under conditions of low mean annual shortwave radiation and low above-ground biomass. It suggests that this specific condition might play a key role in critical transitions between the two modes, while under other conditions no bimodality was found. Based on a land cover map in which anthropogenic land use was removed, six climatic indicators that represent water, energy, climate seasonality and water–radiation coupling are analysed to investigate the coexistence of these indicators with specific land cover types. From this analysis we find that the mean annual precipitation is not sufficient to predict potential land cover change. Indicators of climate seasonality are strongly related to the observed land cover type. However, these indicators cannot predict a stable forest state under the observed climatic conditions, in contrast to observed forest states. A new indicator (the normalized difference of precipitation) successfully expresses the stability of the precipitation regime and can improve the prediction accuracy of forest states. Next we evaluate land cover predictions based on different combinations of climatic indicators. Regions with high potential of land cover transitions are revealed. The results suggest that the tropical forest in the Congo basin may be unstable and shows the possibility of decreasing significantly. An increase in the area covered by savanna and grass is possible, which coincides with the observed regreening of the Sahara.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Andrea Y Frommel ◽  
Justin Carless ◽  
Brian P V Hunt ◽  
Colin J Brauner

Abstract Pacific salmon stocks are in decline with climate change named as a contributing factor. The North Pacific coast of British Columbia is characterized by strong temporal and spatial heterogeneity in ocean conditions with upwelling events elevating CO2 levels up to 10-fold those of pre-industrial global averages. Early life stages of pink salmon have been shown to be affected by these CO2 levels, and juveniles naturally migrate through regions of high CO2 during the energetically costly phase of smoltification. To investigate the physiological response of out-migrating wild juvenile pink salmon to these naturally occurring elevated CO2 levels, we captured fish in Georgia Strait, British Columbia and transported them to a marine lab (Hakai Institute, Quadra Island) where fish were exposed to one of three CO2 levels (850, 1500 and 2000 μatm CO2) for 2 weeks. At ½, 1 and 2 weeks of exposure, we measured their weight and length to calculate condition factor (Fulton’s K), as well as haematocrit and plasma [Cl−]. At each of these times, two additional stressors were imposed (hypoxia and temperature) to provide further insight into their physiological condition. Juvenile pink salmon were largely robust to elevated CO2 concentrations up to 2000 μatm CO2, with no mortality or change in condition factor over the 2-week exposure duration. After 1 week of exposure, temperature and hypoxia tolerance were significantly reduced in high CO2, an effect that did not persist to 2 weeks of exposure. Haematocrit was increased by 20% after 2 weeks in the CO2 treatments relative to the initial measurements, while plasma [Cl−] was not significantly different. Taken together, these data indicate that juvenile pink salmon are quite resilient to naturally occurring high CO2 levels during their ocean outmigration.


2021 ◽  
Vol 21 ◽  
pp. 100462
Author(s):  
Sadhana Yadav ◽  
Hitendra Padalia ◽  
Sanjiv K. Sinha ◽  
Ritika Srinet ◽  
Prakash Chauhan

2020 ◽  
Vol 5 (1) ◽  
pp. 13
Author(s):  
Negar Tavasoli ◽  
Hossein Arefi

Assessment of forest above ground biomass (AGB) is critical for managing forest and understanding the role of forest as source of carbon fluxes. Recently, satellite remote sensing products offer the chance to map forest biomass and carbon stock. The present study focuses on comparing the potential use of combination of ALOSPALSAR and Sentinel-1 SAR data, with Sentinel-2 optical data to estimate above ground biomass and carbon stock using Genetic-Random forest machine learning (GA-RF) algorithm. Polarimetric decompositions, texture characteristics and backscatter coefficients of ALOSPALSAR and Sentinel-1, and vegetation indices, tasseled cap, texture parameters and principal component analysis (PCA) of Sentinel-2 based on measured AGB samples were used to estimate biomass. The overall coefficient (R2) of AGB modelling using combination of ALOSPALSAR and Sentinel-1 data, and Sentinel-2 data were respectively 0.70 and 0.62. The result showed that Combining ALOSPALSAR and Sentinel-1 data to predict AGB by using GA-RF model performed better than Sentinel-2 data.


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