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Sample records for microbial biomass estimated

  1. 11 Soil Microbial Biomass

    African Journals Online (AJOL)

    186–198. Insam H. (1990). Are the soil microbial biomass and basal respiration governed by the climatic regime? Soil. Biol. Biochem. 22: 525–532. Insam H. D. and Domsch K. H. (1989). Influence of microclimate on soil microbial biomass. Soil Biol. Biochem. 21: 211–21. Jenkinson D. S. (1988). Determination of microbial.

  2. Conditioning biomass for microbial growth

    Science.gov (United States)

    Bodie, Elizabeth A; England, George

    2015-03-31

    The present invention relates to methods for improving the yield of microbial processes that use lignocellulose biomass as a nutrient source. The methods comprise conditioning a composition comprising lignocellulose biomass with an enzyme composition that comprises a phenol oxidizing enzyme. The conditioned composition can support a higher rate of growth of microorganisms in a process. In one embodiment, a laccase composition is used to condition lignocellulose biomass derived from non-woody plants, such as corn and sugar cane. The invention also encompasses methods for culturing microorganisms that are sensitive to inhibitory compounds in lignocellulose biomass. The invention further provides methods of making a product by culturing the production microorganisms in conditioned lignocellulose biomass.

  3. Limitations of ATP as a measure of microbial biomass

    African Journals Online (AJOL)

    limits the use of ATP as a measure of microbial biomass. S. AIr. J. Zool. 1982, 17: 93 - 95. Beraming van die totale .... only micro-organisms present in the experimental culture, but these were later succeeded by a large ... a value of 49: I by the last day of the experiment. Estimates of the total living biomass of the heterotro-.

  4. Phosphorus fractions, microbial biomass and enzyme activities in ...

    African Journals Online (AJOL)

    Potohar, northern Punjab, Pakistan in September, 2008 and analysed for P fractions and microbial parameters including microbial biomass C, microbial biomass N, microbial biomass P, and activities of dehydrogenase and alkaline phosphatase enzymes. The average size of different P fractions (% of total P) in the soils ...

  5. Impact of Wildfire on Microbial Biomass in Critical Zone Observatory

    Science.gov (United States)

    Murphy, M. A.; Fairbanks, D.; Chorover, J.; Gallery, R. E.; Rich, V. I.

    2014-12-01

    The recovery of the critical zone following disturbances such as wildfire is not fully understood. Wildfires have increased in size and intensity in western US forests in recent years and these fires influence soil microbial communities, both in composition and overall biomass. Studies have typically shown a 50% post-fire decline in overall microbial biomass (µg per g soil) that can persist for years. There is however, some variability in the severity of biomass decline, and its relationship with burn severity and landscape position have not yet been studied. Since microbial biomass has a cascade of impacts in soil systems, from helping control the rate and diversity the biogeochemical processes occurring, to promoting soil fertility, to impacting the nature and structure of soil carbon (C), fire's lasting impact on it is one mechanistic determinant of the overall post-fire recovery of impacted ecosystems. Additionally, microbial biomass measurements hold potential for testing and incorporation into land surface models (NoahMP, CLM, etc.) in order to improve estimates of long-term effects of climate change and disturbances such as fire on the C cycle. In order to refine our understanding of the impact of fire on microbial biomass and then relate that to biogeochemical processes and ecosystem recovery, we used chloroform fumigation extraction to quantify total microbial biomass C (Cmic ). One year after the June 2013 Thompson Ridge fire in the Jemez River Basin Critical Zone Observatory, we are measuring the Cmic of 22 sites across a gradient of burn severities and 4 control unburned sites, from six depth intervals at each site (0-2, 2-5, 5-10, 10-20, 20-30, and 30-40 cm). We hypothesize that the decrease in microbial biomass in burned sites relative to control sites will correlate with changes in soil biogeochemistry related to burn severity; and that the extent of the impact on biomass will be inversely related to depth in the soil column. Additionally, as the

  6. Estimating Swedish biomass energy supply

    International Nuclear Information System (INIS)

    Johansson, J.; Lundqvist, U.

    1999-01-01

    Biomass is suggested to supply an increasing amount of energy in Sweden. There have been several studies estimating the potential supply of biomass energy, including that of the Swedish Energy Commission in 1995. The Energy Commission based its estimates of biomass supply on five other analyses which presented a wide variation in estimated future supply, in large part due to differing assumptions regarding important factors. In this paper, these studies are assessed, and the estimated potential biomass energy supplies are discusses regarding prices, technical progress and energy policy. The supply of logging residues depends on the demand for wood products and is limited by ecological, technological, and economic restrictions. The supply of stemwood from early thinning for energy and of straw from cereal and oil seed production is mainly dependent upon economic considerations. One major factor for the supply of willow and reed canary grass is the size of arable land projected to be not needed for food and fodder production. Future supply of biomass energy depends on energy prices and technical progress, both of which are driven by energy policy priorities. Biomass energy has to compete with other energy sources as well as with alternative uses of biomass such as forest products and food production. Technical progress may decrease the costs of biomass energy and thus increase the competitiveness. Economic instruments, including carbon taxes and subsidies, and allocation of research and development resources, are driven by energy policy goals and can change the competitiveness of biomass energy

  7. Quantitative analysis of microbial biomass yield in aerobic bioreactor.

    Science.gov (United States)

    Watanabe, Osamu; Isoda, Satoru

    2013-12-01

    We have studied the integrated model of reaction rate equations with thermal energy balance in aerobic bioreactor for food waste decomposition and showed that the integrated model has the capability both of monitoring microbial activity in real time and of analyzing biodegradation kinetics and thermal-hydrodynamic properties. On the other hand, concerning microbial metabolism, it was known that balancing catabolic reactions with anabolic reactions in terms of energy and electron flow provides stoichiometric metabolic reactions and enables the estimation of microbial biomass yield (stoichiometric reaction model). We have studied a method for estimating real-time microbial biomass yield in the bioreactor during food waste decomposition by combining the integrated model with the stoichiometric reaction model. As a result, it was found that the time course of microbial biomass yield in the bioreactor during decomposition can be evaluated using the operational data of the bioreactor (weight of input food waste and bed temperature) by the combined model. The combined model can be applied to manage a food waste decomposition not only for controlling system operation to keep microbial activity stable, but also for producing value-added products such as compost on optimum condition. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  8. Tillage and manure effect on soil microbial biomass and respiration ...

    African Journals Online (AJOL)

    The objective of this study was to determine the influence of both tillage and liquid pig manure application on soil microbial biomass, enzyme activities and microbial respiration in a meadow soil. The results obtained did not show any significant effect of tillage and manure on microbial biomass carbon (C) and nitrogen (N) ...

  9. [Microbial biomass and growth kinetics of microorganisms in chernozem soils under different farm land use modes].

    Science.gov (United States)

    Blagodatskiĭ, S A; Bogomolova, I N; Blagodatskaia, E V

    2008-01-01

    The carbon content of microbial biomass and the kinetic characteristics of microbial respiration response to substrate introduction have been estimated for chernozem soils of different farm lands: arable lands used for 10, 46, and 76 years, mowed fallow land, non-mowed fallow land, and woodland. Microbial biomass and the content of microbial carbon in humus (Cmic/Corg) decreased in the following order: soils under forest cenoses-mowed fallow land-10-year arable land-46- and 75-year arable land. The amount of microbial carbon in the long-plowed horizon was 40% of its content in the upper horizon of non-mowed fallow land. Arable soils were characterized by a lower metabolic diversity of microbial community and by the highest portion of microorganisms able to grow directly on glucose introduced into soil. The effects of different scenarios of carbon sequestration in soil on the reserves and activity of microbial biomass are discussed.

  10. A global analysis of soil microbial biomass carbon, nitrogen and phosphorus in terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xiaofeng [ORNL; Thornton, Peter E [ORNL; Post, Wilfred M [ORNL

    2013-01-01

    Soil microbes play a pivotal role in regulating land-atmosphere interactions; the soil microbial biomass carbon (C), nitrogen (N), phosphorus (P) and C:N:P stoichiometry are important regulators for soil biogeochemical processes; however, the current knowledge on magnitude, stoichiometry, storage, and spatial distribution of global soil microbial biomass C, N, and P is limited. In this study, 3087 pairs of data points were retrieved from 281 published papers and further used to summarize the magnitudes and stoichiometries of C, N, and P in soils and soil microbial biomass at global- and biome-levels. Finally, global stock and spatial distribution of microbial biomass C and N in 0-30 cm and 0-100 cm soil profiles were estimated. The results show that C, N, and P in soils and soil microbial biomass vary substantially across biomes; the fractions of soil nutrient C, N, and P in soil microbial biomass are 1.6% in a 95% confidence interval of (1.5%-1.6%), 2.9% in a 95% confidence interval of (2.8%-3.0%), and 4.4% in a 95% confidence interval of (3.9%-5.0%), respectively. The best estimates of C:N:P stoichiometries for soil nutrients and soil microbial biomass are 153:11:1, and 47:6:1, respectively, at global scale, and they vary in a wide range among biomes. Vertical distribution of soil microbial biomass follows the distribution of roots up to 1 m depth. The global stock of soil microbial biomass C and N were estimated to be 15.2 Pg C and 2.3 Pg N in the 0-30 cm soil profiles, and 21.2 Pg C and 3.2 Pg N in the 0-100 cm soil profiles. We did not estimate P in soil microbial biomass due to data shortage and insignificant correlation with soil total P and climate variables. The spatial patterns of soil microbial biomass C and N were consistent with those of soil organic C and total N, i.e. high density in northern high latitude, and low density in low latitudes and southern hemisphere.

  11. Role of Bioreactors in Microbial Biomass and Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liang [Chongqing University, Chongqing, China; Zhang, Biao [Chongqing University, Chongqing, China; Zhu, Xun [Chongqing University, Chongqing, China; Chang, Haixing [Chongqing University of Technology; Ou, Shawn [ORNL; Wang, HONG [Chongqing University, Chongqing, China

    2018-04-01

    Bioenergy is the world’s largest contributor to the renewable and sustainable energy sector, and it plays a significant role in various energy industries. A large amount of research has contributed to the rapidly evolving field of bioenergy and one of the most important topics is the use of the bioreactor. Bioreactors play a critical role in the successful development of technologies for microbial biomass cultivation and energy conversion. In this chapter, after a brief introduction to bioreactors (basic concepts, configurations, functions, and influencing factors), the applications of the bioreactor in microbial biomass, microbial biofuel conversion, and microbial electrochemical systems are described. Importantly, the role and significance of the bioreactor in the bioenergy process are discussed to provide a better understanding of the use of bioreactors in managing microbial biomass and energy conversion.

  12. Estimates of US biomass energy consumption 1992

    International Nuclear Information System (INIS)

    1994-01-01

    This report is the seventh in a series of publications developed by the Energy Information Administration (EIA) to quantify the biomass-derived primary energy used by the US economy. It presents estimates of 1991 and 1992 consumption. The objective of this report is to provide updated estimates of biomass energy consumption for use by Congress, Federal and State agencies, biomass producers and end-use sectors, and the public at large

  13. Estimates of US biomass energy consumption 1992

    Energy Technology Data Exchange (ETDEWEB)

    1994-05-06

    This report is the seventh in a series of publications developed by the Energy Information Administration (EIA) to quantify the biomass-derived primary energy used by the US economy. It presents estimates of 1991 and 1992 consumption. The objective of this report is to provide updated estimates of biomass energy consumption for use by Congress, Federal and State agencies, biomass producers and end-use sectors, and the public at large.

  14. Seasonal variability of microbial biomass phosphorus in urban soils.

    Science.gov (United States)

    Halecki, W; Gąsiorek, M

    2015-01-01

    Urban soils have been formed through human activities. Seasonal evaluation with time-control procedure are essential for plant, and activity of microorganisms. Therefore, these processes are crucial in the urban area due to geochemical changes in the past years. The purpose of this study was to investigate the changes of content of microbial biomass phosphorus (P) in the top layer of soils throughout the season. In this research, the concentration of microbial biomass P ranged from 0.01 to 6.29 mg·kg(-1). We used single-factor repeated-measure analysis of variance to test the effect of season on microbial biomass P content of selected urban soils. We found no statistically significant differences between the concentration of microbial biomass P in the investigated urban and sub-urban soils during the growing season. This analysis explicitly recognised that environmental urban conditions are steady. Specifically, we have studied how vegetation seasonality and ability of microbial biomass P are useful for detecting quality deviations, which affect the equilibrium of urban soil. In conclusion, seasonal variability of the stringency of assurance across the different compounds of soil reveals, as expected, the stable condition of the urban soils. Seasonal responses in microbial biomass P under urban soil use should establish a framework as a reference to the activity of the microorganisms. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Short-term parasite-infection alters already the biomass, activity and functional diversity of soil microbial communities

    Science.gov (United States)

    Li, Jun-Min; Jin, Ze-Xin; Hagedorn, Frank; Li, Mai-He

    2014-11-01

    Native parasitic plants may be used to infect and control invasive plants. We established microcosms with invasive Mikania micrantha and native Coix lacryma-jobi growing in mixture on native soils, with M. micrantha being infected by parasitic Cuscuta campestris at four intensity levels for seven weeks to estimate the top-down effects of plant parasitism on the biomass and functional diversity of soil microbial communities. Parasitism significantly decreased root biomass and altered soil microbial communities. Soil microbial biomass decreased, but soil respiration increased at the two higher infection levels, indicating a strong stimulation of soil microbial metabolic activity (+180%). Moreover, a Biolog assay showed that the infection resulted in a significant change in the functional diversity indices of soil microbial communities. Pearson correlation analysis indicated that microbial biomass declined significantly with decreasing root biomass, particularly of the invasive M. micrantha. Also, the functional diversity indices of soil microbial communities were positively correlated with soil microbial biomass. Therefore, the negative effects on the biomass, activity and functional diversity of soil microbial community by the seven week long plant parasitism was very likely caused by decreased root biomass and root exudation of the invasive M. micrantha.

  16. A tree biomass and carbon estimation system

    Science.gov (United States)

    Emily B. Schultz; Thomas G. Matney; Donald L. Grebner

    2013-01-01

    Appropriate forest management decisions for the developing woody biofuel and carbon credit markets require inventory and growth-and-yield systems reporting component tree dry weight biomass estimates. We have developed an integrated growth-and-yield and biomass/carbon calculator. The objective was to provide Mississippi’s State inventory system with bioenergy economic...

  17. Soil microbial biomass in an agroforestry system of Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Rosane C. Rodrigues

    2015-01-01

    Full Text Available Agroforestry systems (AFS are considered alternative land use options to help prevent soil degradation and improve soil microbial biomass and organic C status. However, it is unclear how different densities of babassu palm [Attalea speciosa (syn. Orbignya phalerata], which is an important tree in Northeast Brazil, affect the soil microbial biomass. We investigated the soil microbial biomass C and activity under AFS with different densities of babassu palm associated with Brachiaria brizantha grass. Soil microbial biomass C (MBC, soil microbial biomass N (MBN, MBC:total organic C ratio, fluorescein diacetate hydrolysis and dehydrogenase activity showed highest values in plots with high density of babassu palm. On the other hand, the respiratory quotient (qCO2 was significantly greater in plots without babassu palm. Brachiaria brizantha in monoculture may promote C losses from the soil, but AFS with high density of babassu palm may increase the potential of soils to accumulate C.Keywords: Enzyme activity, tropical soil, babassu palm, silvopastoral system, soil quality.DOI: 10.17138/TGFT(341-48

  18. Measurement and characteristics of microbial biomass in forest soils

    International Nuclear Information System (INIS)

    Vance, E.D.

    1986-01-01

    The soil microbial biomass is the primary agent responsible for the breakdown and mineralization of soil organic matter and plays a major role in regulating nutrient availability to plants. In this study, methods for measuring biomass in soil were compared and tested in forest soils ranging in pH from 3.2 to 7.2. A good relationship between biomass C measured using the chloroform fumigation-incubation method and soil ATP or microbial biomass C by direct microscopy was found in soils at or above pH 4.2. The fumigation-incubation method consistently underestimated biomass C in soils below pH 4.2, however. Hypotheses for the breakdown of the fumigation-incubation method in strongly acid soils were tested by using an alterative fumigant, measuring the proportion of added 14 C labelled fungi and bacteria decomposed in fumigated soils (k/sub C/), and by studying the effect of large, non-fumigated soil inocula on the flush of respiration following fumigation. These studies indicated that the failure of the method in strongly acid soils was due to inhibited decomposition of non-microbial soil organic matter by the microbial recolonizing population following fumigation. A modified method for measuring biomass C by fumigation-incubation in acid soils is proposed

  19. BIOMASS AND MICROBIAL ACTIVITY UNDER DIFFERENT FOREST COVERS

    Directory of Open Access Journals (Sweden)

    Rafael Malfitano Braga

    2016-06-01

    Full Text Available This study evaluated the soil fertility, biomass and microbial activity of the soil under forest cover of Eucalyptus grandis, Eucalyptus pilularis, Eucalyptus cloeziana and Corymbia maculata; Pinus Caribbean var. hondurensis, 40 years old, and a fragment of Semideciduous Forest, located on the campus of the Federal University of Lavras. In soil samples collected in the 0-5 cm layer were determined fertility parameters, basal respiration and microbial biomass carbon. The results showed that for the species E. grandis and E. cloeziana the carbon of biomass microbial content was higher than for any other ecosystem evaluated, and equal to those observed under native forest. In contrast, the ground under Pinus had the lowest microbiological indexes. Under C. maculata and E. pilularis the contents were intermediate for this parameter. The basal respiration of all ecosystems was equal. The fertility level was very low in all types of evaluated vegetation.

  20. The contribution of microbial biomass to the adsorption of radioiodide in soils

    International Nuclear Information System (INIS)

    Bors, J.; Martens, R.

    1992-01-01

    The contribution of soil microbial biomass to the sorption and migration of radiodide in soil has been investigated. In two arable soils, a chernozem and a podzol, the numbers of microorganisms were either reduced by biocidal treatment or increased by addition of nutrient sources. Radioiodide ( 125 I - ) adsorption by the pretreated soils was measured, relative to untreated soil samples, in aqueous suspensions containing iodide by estimating the distribution coefficient (K d ) after eight days of incubation. A reduction of biomass to about 10% of its original level drastically decreased adsorption. Elevated levels of microbial biomass (up to 126%) increased adsorption but the increase was not always correlated with biomass level. A closer correlation between soil biomass and adsorption was observed when the concentration of radioiodide in the suspension was increased by several orders of magnitude. Conditions such as anarobiosis and elevated temperatures which are known to influence the activity and survival of microorganisms also exerted an effect on radioiodide sorption. In accordance with the relationship described here between radioiodide adsorption and microbial biomass, migration in water saturated soil columns was influenced by the quantity of microorganisms present. However, high biomass contents obviously caused anaerobic conditions in the system, leading to increased leaching of radioiodide. (author)

  1. The contribution of microbial biomass to the adsorption of radioiodide in soils

    Energy Technology Data Exchange (ETDEWEB)

    Bors, J. (Niedersaechsisches Inst. fuer Radiooekologie, Hannover (Germany)); Martens, R. (Bundesforschungsanstalt fuer Landwirtschaft, Braunschweig (Germany). Inst. fuer Biochemie des Bodens)

    1992-01-01

    The contribution of soil microbial biomass to the sorption and migration of radiodide in soil has been investigated. In two arable soils, a chernozem and a podzol, the numbers of microorganisms were either reduced by biocidal treatment or increased by addition of nutrient sources. Radioiodide ({sup 125}I{sup -}) adsorption by the pretreated soils was measured, relative to untreated soil samples, in aqueous suspensions containing iodide by estimating the distribution coefficient (K{sub d}) after eight days of incubation. A reduction of biomass to about 10% of its original level drastically decreased adsorption. Elevated levels of microbial biomass (up to 126%) increased adsorption but the increase was not always correlated with biomass level. A closer correlation between soil biomass and adsorption was observed when the concentration of radioiodide in the suspension was increased by several orders of magnitude. Conditions such as anarobiosis and elevated temperatures which are known to influence the activity and survival of microorganisms also exerted an effect on radioiodide sorption. In accordance with the relationship described here between radioiodide adsorption and microbial biomass, migration in water saturated soil columns was influenced by the quantity of microorganisms present. However, high biomass contents obviously caused anaerobic conditions in the system, leading to increased leaching of radioiodide. (author).

  2. Effects of uranium on soil microbial biomass carbon, enzymes, plant biomass and microbial diversity in yellow soils

    International Nuclear Information System (INIS)

    Yan, X.; Zhang, Y.; Luo, X.; Yu, L.

    2016-01-01

    We conducted an experiment to investigate the effects of uranium (U) on soil microbial biomass carbon (MBC), enzymes, plant biomass and microbial diversity in yellow soils under three concentrations: 0 mg kg"-"1 (T1, control), 30 mg kg"-"1 (T2) and 60 mg kg"-"1 (T3). Under each treatment, elevated U did not reduce soil MBC or plant biomass, but inhibited the activity of the soil enzymes urease (UR), dehydrogenase (DH) and phosphatase (PHO). The microbial diversity was different, with eight dominant phyla in T1 and six in T2 and T3. Furthermore, Proteobacteria and material X were both detected in each treatment site (T1, T2 and T3). Pseudomonas sp. was the dominant strain, followed by Acidiphilium sp. This initial study provided valuable data for further research toward a better understanding of U contamination in yellow soils in China. (authors)

  3. Measures of Microbial Biomass for Soil Carbon Decomposition Models

    Science.gov (United States)

    Mayes, M. A.; Dabbs, J.; Steinweg, J. M.; Schadt, C. W.; Kluber, L. A.; Wang, G.; Jagadamma, S.

    2014-12-01

    Explicit parameterization of the decomposition of plant inputs and soil organic matter by microbes is becoming more widely accepted in models of various complexity, ranging from detailed process models to global-scale earth system models. While there are multiple ways to measure microbial biomass, chloroform fumigation-extraction (CFE) is commonly used to parameterize models.. However CFE is labor- and time-intensive, requires toxic chemicals, and it provides no specific information about the composition or function of the microbial community. We investigated correlations between measures of: CFE; DNA extraction yield; QPCR base-gene copy numbers for Bacteria, Fungi and Archaea; phospholipid fatty acid analysis; and direct cell counts to determine the potential for use as proxies for microbial biomass. As our ultimate goal is to develop a reliable, more informative, and faster methods to predict microbial biomass for use in models, we also examined basic soil physiochemical characteristics including texture, organic matter content, pH, etc. to identify multi-factor predictive correlations with one or more measures of the microbial community. Our work will have application to both microbial ecology studies and the next generation of process and earth system models.

  4. Membrane bioreactor biomass characteristics and microbial yield at ...

    African Journals Online (AJOL)

    In this study, a laboratory-scale MBR and SBR were operated in parallel and at very low MCRTs (3 d, 2 d, 1 d and 0.5 d) to assess the relative bioreactor performance, biomass characteristics, and microbial yield. This study confirmed that the MBR maintains higher solids levels and better overall effluent quality than ...

  5. Efficient Methods of Estimating Switchgrass Biomass Supplies

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) is being developed as a biofuel feedstock for the United States. Efficient and accurate methods to estimate switchgrass biomass feedstock supply within a production area will be required by biorefineries. Our main objective was to determine the effectiveness of in...

  6. The survival strategy of the soil microbial biomass

    Science.gov (United States)

    Brookes, Philip; Kemmitt, Sarah; Dungait, Jennifer; Xu, Jianming

    2014-05-01

    The soil microbial biomass (biomass) is defined as the sum of the masses of all soil microorganisms > 5000 µm3 (e.g. fungi, bacteria, protozoa, yeasts, actinomycetes and algae). Typically comprising about 1 to 3 % of total soil organic matter (SOM), the biomass might be though to live in a highly substrate-rich environment. However, the SOM is, normally, only exceedingly slowly available to the biomass. However the biomass can survive for months or even years on this meagre energy source. Not surprisingly, therefore, the biomass exhibits many features typical of a dormant or resting population. These include a very low rate of basal and specific respiration, a slow rate of cell division (about once every six months on average) and slow turnover rate. These are clearly adaptations to existing in an environment where substrate availability is very low. Yet, paradoxically, the biomass, in soils worldwide, has an adenosine triphosphate (ATP) concentration (around 10 to 12 µmol ATP g-1 biomass C), and an Adenylate Energy Charge (AEC = [(ATP) + (0.5 ADP)]/[(ATP)+(ADP) + (AMP)]) which are typical of microorganisms growing exponentially in a chemostat. This sets us several questions. Firstly, under the condition of extremely limited substrate availability in soil, why does the biomass not mainly exist as spores, becoming active, by increasing both its ATP concentration and AEC, when substrate (plant and animal residues) becomes available? We surmise that a spore strategy may put organisms at a competitive disadvantage, compared to others which are prepared to invest energy, maintaining high ATP and ATP, to take advantage of a 'food event' as soon as it becomes available. Secondly, since SOM is available (although only very slowly) to the biomass, why have some groups not evolved the ability to mineralize it faster, obtain more energy, and so gain a competitive advantage? We believe that the reason why organisms do not use this strategy is, simply, that they cannot. Our

  7. Microbial respiration per unit microbial biomass increases with carbon-to-nutrient ratios in soils

    Science.gov (United States)

    Spohn, Marie; Chodak, Marcin

    2015-04-01

    The ratio of carbon-to-nutrient in forest floors is usually much higher than the ratio of carbon-to-nutrient that soil microorganisms require for their nutrition. In order to understand how this mismatch affects carbon cycling, the respiration rate per unit soil microbial biomass carbon - the metabolic quotient (qCO2) - was studied. This was done in a field study (Spohn and Chodak, 2015) and in a meta-analysis of published data (Spohn, 2014). Cores of beech, spruce, and mixed spruce-beech forest soils were cut into slices of 1 cm from the top of the litter layer down to 5 cm in the mineral soil, and the relationship between the qCO2 and the soil carbon-to-nitrogen (C:N) and the soil carbon-to-phosphorus (C:P) ratio was analyzed. We found that the qCO2 was positively correlated with soil C:N ratio in spruce soils (R = 0.72), and with the soil C:P ratio in beech (R = 0.93), spruce (R = 0.80) and mixed forest soils (R = 0.96). We also observed a close correlation between the qCO2 and the soil C concentration in all three forest types. Yet, the qCO2 decreased less with depth than the C concentration in all three forest types, suggesting that the change in qCO2 is not only controlled by the soil C concentration. We conclude that microorganisms increase their respiration rate per unit biomass with increasing soil C:P ratio and C concentration, which adjusts the substrate to their nutritional demands in terms of stoichiometry. In an analysis of literature data, I tested the effect of the C:N ratio of soil litter layers on microbial respiration in absolute terms and per unit microbial biomass C. For this purpose, a global dataset on the microbial respiration rate per unit microbial biomass C - termed the metabolic quotient (qCO2) - was compiled form literature data. It was found that the qCO2 in the soil litter layers was positively correlated with the litter C:N ratio and negatively related with the litter nitrogen (N) concentration. The positive relation between the qCO2

  8. [Estimation of Shenyang urban forest green biomass].

    Science.gov (United States)

    Liu, Chang-fu; He, Xing-yuan; Chen, Wei; Zhao, Gui-ling; Xu, Wen-duo

    2007-06-01

    Based on ARC/GIS and by using the method of "planar biomass estimation", the green biomass (GB) of Shenyang urban forests was measured. The results demonstrated that the GB per unit area was the highest (3.86 m2.m(-2)) in landscape and relaxation forest, and the lowest (2.27 m2.m(-2)) in ecological and public welfare forest. The GB per unit area in urban forest distribution area was 2.99 m2.m(-2), and that of the whole Shenyang urban area was 0.25 m2.m(-2). The total GB of Shenyang urban forests was about 1.13 x 10(8) m2, among which, subordinated forest, ecological and public welfare forest, landscape and relaxation forest, road forest, and production and management forest accounted for 36.64% , 23.99% , 19.38% , 16.20% and 3.79%, with their GB being 4. 15 x 10(7), 2.72 x 10(7), 2.20 x 10(7), 1.84 x 10(7) and 0.43 x 10(7) m2, respectively. The precision of the method "planar biomass estimation" was 91.81% (alpha = 0.05) by credit test.

  9. Rumen microbial growth estimation using in vitro radiophosphorous incorporation technique

    International Nuclear Information System (INIS)

    Bueno, Ives Claudio da Silva; Machado, Mariana de Carvalho; Cabral Filho, Sergio Lucio Salomon; Gobbo, Sarita Priscila; Vitti, Dorinha Miriam Silber Schmidt; Abdalla, Adibe Luiz

    2002-01-01

    Rumen microorganisms are able to transform low biological value nitrogen of feed stuff into high quality protein. To determine how much microbial protein that process forms, radiomarkers can be used. Radiophosphorous has been used to mark microbial protein, as element P is present in all rumen microorganisms (as phospholipids) and the P:N ratio of rumen biomass is quite constant. The aim of this work was to estimate microbial synthesis from feedstuff commonly used in ruminant nutrition in Brazil. Tested feeds were fresh alfalfa, raw sugarcane bagasse, rice hulls, rice meal, soybean meal, wheat meal, Tifton hay, leucaena, dehydrated citrus pulp, wet brewers' grains and cottonseed meal. 32 P-labelled phosphate solution was used as marker for microbial protein. Results showed the diversity of feeds by distinct quantities of nitrogen incorporated into microbial mass. Low nutrient availability feeds (sugarcane bagasse and rice hulls) promoted the lowest values of incorporated nitrogen. Nitrogen incorporation showed positive relationship (r=0.56; P=0.06) with the rate of degradation and negative relationship (r=-0.59; P<0.05) with fiber content of feeds. The results highlight that easier fermentable feeds (higher rates of degradation) and/or with lower fiber contents promote a more efficient microbial growth and better performance for the host animal. (author)

  10. Rumen microbial growth estimation using in vitro radiophosphorous incorporation technique

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Ives Claudio da Silva; Machado, Mariana de Carvalho; Cabral Filho, Sergio Lucio Salomon; Gobbo, Sarita Priscila; Vitti, Dorinha Miriam Silber Schmidt; Abdalla, Adibe Luiz [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    2002-07-01

    Rumen microorganisms are able to transform low biological value nitrogen of feed stuff into high quality protein. To determine how much microbial protein that process forms, radiomarkers can be used. Radiophosphorous has been used to mark microbial protein, as element P is present in all rumen microorganisms (as phospholipids) and the P:N ratio of rumen biomass is quite constant. The aim of this work was to estimate microbial synthesis from feedstuff commonly used in ruminant nutrition in Brazil. Tested feeds were fresh alfalfa, raw sugarcane bagasse, rice hulls, rice meal, soybean meal, wheat meal, Tifton hay, leucaena, dehydrated citrus pulp, wet brewers' grains and cottonseed meal. {sup 32} P-labelled phosphate solution was used as marker for microbial protein. Results showed the diversity of feeds by distinct quantities of nitrogen incorporated into microbial mass. Low nutrient availability feeds (sugarcane bagasse and rice hulls) promoted the lowest values of incorporated nitrogen. Nitrogen incorporation showed positive relationship (r=0.56; P=0.06) with the rate of degradation and negative relationship (r=-0.59; P<0.05) with fiber content of feeds. The results highlight that easier fermentable feeds (higher rates of degradation) and/or with lower fiber contents promote a more efficient microbial growth and better performance for the host animal. (author)

  11. Renewable biofuels bioconversion of lignocellulosic biomass by microbial community

    CERN Document Server

    Rana, Vandana

    2017-01-01

    This book offers a complete introduction for novices to understand key concepts of biocatalysis and how to produce in-house enzymes that can be used for low-cost biofuels production. The authors discuss the challenges involved in the commercialization of the biofuel industry, given the expense of commercial enzymes used for lignocellulose conversion. They describe the limitations in the process, such as complexity of lignocellulose structure, different microbial communities’ actions and interactions for degrading the recalcitrant structure of lignocellulosic materials, hydrolysis mechanism and potential for bio refinery. Readers will gain understanding of the key concepts of microbial catalysis of lignocellulosic biomass, process complexities and selection of microbes for catalysis or genetic engineering to improve the production of bioethanol or biofuel.

  12. A meta-analysis of soil microbial biomass responses to forest disturbances

    Directory of Open Access Journals (Sweden)

    Sandra Robin Holden

    2013-06-01

    Full Text Available Climate warming is likely to increase the frequency and severity of forest disturbances, with uncertain consequences for soil microbial communities and their contribution to ecosystem C dynamics. To address this uncertainty, we conducted a meta-analysis of 139 published soil microbial responses to forest disturbances. These disturbances included abiotic (fire, harvesting, storm and biotic (insect, pathogen disturbances. We hypothesized that soil microbial biomass would decline following forest disturbances, but that abiotic disturbances would elicit greater reductions in microbial biomass than biotic disturbances. In support of this hypothesis, across all published studies, disturbances reduced soil microbial biomass by an average of 29.4%. However, microbial responses differed between abiotic and biotic disturbances. Microbial responses were significantly negative following fires, harvest, and storms (48.7%, 19.1%, and 41.7% reductions in microbial biomass, respectively. In contrast, changes in soil microbial biomass following insect infestation and pathogen-induced tree mortality were non-significant, although biotic disturbances were poorly represented in the literature. When measured separately, fungal and bacterial responses to disturbances mirrored the response of the microbial community as a whole. Changes in microbial abundance following disturbance were significantly positively correlated with changes in microbial respiration. We propose that the differential effect of abiotic and biotic disturbances on microbial biomass may be attributable to differences in soil disruption and organic C removal from forests among disturbance types. Altogether, these results suggest that abiotic forest disturbances may significantly decrease soil microbial abundance, with corresponding consequences for microbial respiration. Further studies are needed on the effect of biotic disturbances on forest soil microbial communities and soil C dynamics.

  13. Soil plus root respiration and microbial biomass following water, nitrogen, and phosphorus application at a high arctic semi desert

    DEFF Research Database (Denmark)

    Illeris, Lotte; Michelsen, Anders; Jonasson, Sven Evert

    2003-01-01

    CO2 emmision, Decomposition, Microbial biomass carbon, Soil organic matter, Tundra, Water and nutrient limitation......CO2 emmision, Decomposition, Microbial biomass carbon, Soil organic matter, Tundra, Water and nutrient limitation...

  14. Evaluation of sampling strategies to estimate crown biomass

    Science.gov (United States)

    Krishna P Poudel; Hailemariam Temesgen; Andrew N Gray

    2015-01-01

    Depending on tree and site characteristics crown biomass accounts for a significant portion of the total aboveground biomass in the tree. Crown biomass estimation is useful for different purposes including evaluating the economic feasibility of crown utilization for energy production or forest products, fuel load assessments and fire management strategies, and wildfire...

  15. Tree height integrated into pantropical forest biomass estimates

    NARCIS (Netherlands)

    Feldpausch, T.R.; Lloyd, J.; Lewis, S.L.; Brienen, R.J.W.; Gloor, M.; Montegudo Mendoza, A.; Arets, E.J.M.M.

    2012-01-01

    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

  16. Microbial degradation of coconut coir dust for biomass production

    Energy Technology Data Exchange (ETDEWEB)

    Uyenco, F.R.; Ochoa, J.A.K.

    Several species of white-rot fungi were studied for its ability to degrade the lignocellulose components of coir dust at optimum conditions. The most effective fungi was Phanerochaeta chrysosporium UPCC 4003. This organism degraded the lignocellulose complex of coir dust at a rate of about 25 percent in 4 weeks. The degradation process was carried on with minimal nitrogen concentration, coconut water supplementation and moisture levels between 85-90 percent. Shake flask cultures of the degraded coir dust using cellulolytic fungi were not effective. In fermentor cultures with Chaetomium cellulolyticum UPCC 3934, supplemented coir dust was converted into a microbial biomass product (MBP) with 15.58 percent lignin, 19.20 percent cellulose and 18.87 percent protein. More work is being done on the utilization of coir dust on a low technology.

  17. Mineralogical controls on microbial biomass accumulation on two tropical soils

    Science.gov (United States)

    Block, K. A.; Pena, S. A.; Katz, A.; Gottlieb, P.; Volta, A.

    2017-12-01

    The characteristics of soil organic matter (SOM) generated by microbes and associated with minerals are not well defined. This information is critical to reducing uncertainty in climate models related to C cycling and ecosystem feedbacks. The resistance to degradation of mineral-associated SOM is influenced by aggregate structure, mineral chemistry and microbial community. In this work we examine the influence of mineral composition, including amorphous coatings on the biomass yield and aggregate structure through thermogravimetric analysis, X-ray diffraction and electron microscopy. Two soil organisms, Pseudomonas phaseolicola, and Streptomyces griseosporus, were each incubated over a 72-hour period in minimal media with the cultured under the same conditions. In all samples, approximately half of the sample mass loss occurred between 175 ºC - 375 ºC, which we attribute to biomolecules accumulated on the mineral surfaces. We observed a slightly larger mass loss in the Inceptisol than in the Oxisol, most of which corresponded to compounds that underwent pyrolysis at 300 ºC. HRTEM micrographs and TEM-EDS image maps showing the spatial relationship of microbial necromass to soil minerals will be reported.

  18. Does microbial biomass affect pelagic ecosystem efficiency? An experimental study.

    Science.gov (United States)

    Wehr, J D; Le, J; Campbell, L

    1994-01-01

    Bacteria and other microorganisms in the pelagic zone participate in the recycling of organic matter and nutrients within the water column. The microbial loop is thought to enhance ecosystem efficiency through rapid recycling and reduced sinking rates, thus reducing the loss of nutrients contained in organisms remaining within the photic zone. We conducted experiments with lake communities in 5400-liter mesocosms, and measured the flux of materials and nutrients out of the water column. A factorial design manipulated 8 nutrient treatments: 4 phosphorus levels × 2 nitrogen levels. Total sedimentation rates were greatest in high-N mesocosms; within N-surplus communities, [Symbol: see text]1 µM P resulted in 50% increase in total particulate losses. P additions without added N had small effects on nutrient losses from the photic zone; +2 µM P tanks received 334 mg P per tank, yet after 14 days lost only 69 mg more particulate-P than did control communities. Nutrient treatments resulted in marked differences in phytoplankton biomass (twofold N effect, fivefold P effect in +N mesocosms only), bacterioplankton densities (twofold N-effect, twofold P effects in -N and +N mesocosms), and the relative importance of autotrophic picoplankton (maximum in high NY mesocosms). Multiple regression analysis found that of 8 plankton and water chemistry variables, the ratio of autotrophic picoplankton to total phytoplankton (measured as chlorophyll α) explained the largest portion of the total variation in sedimentation loss rates (65% of P-flux, 57% of N-flux, 26% of total flux). In each case, systems with greater relative importance of autotrophic picoplankton had significantly reduced loss rates. In contrast, greater numbers of planktonic bacteria were associated with increased sedimentation rates and lower system efficiency. We suggest that different microbial components may have contrasting effects on the presumed enhanced efficiency provided by the microbial loop.

  19. Biomass assessment of microbial surface communities by means of hyperspectral remote sensing data.

    Science.gov (United States)

    Rodríguez-Caballero, Emilio; Paul, Max; Tamm, Alexandra; Caesar, Jennifer; Büdel, Burkhard; Escribano, Paula; Hill, Joachim; Weber, Bettina

    2017-05-15

    Dryland vegetation developed morphological and physiological strategies to cope with drought. However, as aridity increases, vascular plant coverage gets sparse and microbially-dominated surface communities (MSC), comprising cyanobacteria, algae, lichens and bryophytes together with heterotropic bacteria, archaea and fungi, gain relevance. Nevertheless, the relevance of MSC net primary productivity has only rarely been considered in ecosystem scale studies, and detailed information on their contribution to the total photosynthetic biomass reservoir is largely missing. In this study, we mapped the spatial distribution of two different MSC (biological soil crusts and quartz fields hosting hypolithic crusts) at two different sites within the South African Succulent Karoo (Soebatsfontein and Knersvlakte). Then we characterized both types of MSC in terms of chlorophyll content, and combining these data with the biocrust and quartz field maps, we estimated total biomass values of MSCs and their spatial patterns within the two different ecosystems. Our results revealed that MSC are important vegetation components of the South African Karoo biome, revealing clear differences between the two sites. At Soebatsfontein, MSC occurred as biological soil crusts (biocrusts), which covered about one third of the landscape reaching an overall biomass value of ~480gha -1 of chlorophyll a+b at the landscape scale. In the Knersvlakte, which is characterized by harsher environmental conditions (i.e. higher solar radiation and potential evapotranspiration), MSC occurred as biocrusts, but also formed hypolithic crusts growing on the lower soil-immersed parts of translucent quartz pebbles. Whereas chlorophyll concentrations of biocrusts and hypolithic crusts where insignificantly lower in the Knersvlakte, the overall MSC biomass reservoir was by far larger with ~780gha -1 of chlorophyll a+b. Thus, the complementary microbially-dominated surface communities promoted biomass formation within

  20. Estimation of the biomass of arbuscular mycorrhizal fungi in a linseed field

    DEFF Research Database (Denmark)

    Olsson, P.A.; Thingstrup, I.; Jakobsen, I.

    1999-01-01

    -organisms was estimated 28, 51 and 72 d after sowing based on amounts of certain fatty acids extracted from the soil. Dazomet application strongly suppressed colonisation of the linseed roots by AM fungi throughout the experiment. In plots with no dazomet application, root colonisation by the AM fungi increased from...... that the biomass of the extraradical mycelium of AM fungi was about 10 times as high as the biomass of intraradical mycelium and that the extraradical mycelium constituted the largest fraction of the soil microbial biomass. Dazomet application also decreased the biomass of saprophytic fungi in the soil...... harvests 1 to 3 as judged both from microscopical estimates and from quantitative analysis of the AM fungal indicative fatty acid 16.1 omega 5. These methods also revealed that AM formation was reduced in P-fertilised plots. The phospholipid fatty acid (PLFA) 16:1 omega 5 decreased in dazomet-treated soil...

  1. Carbon use efficiency (CUE) and biomass turnover of soil microbial communities as affected by bedrock, land management and soil temperature and moisture

    Science.gov (United States)

    Zheng, Qing; Hu, Yuntao; Richter, Andreas; Wanek, Wolfgang

    2017-04-01

    Soil microbial carbon use efficiency (CUE), defined as the proportion of organic C taken up that is allocated to microbial growth, represents an important synthetic representation of microbial community C metabolism that describes the flux partitioning between microbial respiration and growth. Therefore, studying microbial CUE is critical for the understanding of soil C cycling. Microbial CUE is thought to vary with environmental conditions (e.g. temperature and soil moisture). Microbial CUE is thought to decrease with increasing temperature and declining soil moisture, as the latter may trigger stress responses (e.g. the synthesis of stress metabolites), which may consequently lower microbial community CUE. However, these effects on microbial CUE have not been adequately measured so far due to methodological restrictions. The most widely used methods for microbial CUE estimation are based on tracing 13C-labeled substrates into microbial biomass and respiratory CO2, approaches that are known to overestimate microbial CUE of native organic matter in soil. Recently, a novel substrate-independent approach based on the measurement of (i) respiration rates and (ii) the incorporation rates of 18O from labelled water into newly formed microbial DNA has been developed in our laboratory for measuring microbial CUE. This approach overcomes the shortcomings of previously used methods and has already been shown to yield realistic estimations of soil microbial CUE. This approach can also be applied to concurrently measure microbial biomass turnover rates, which also influence the sequestration of soil organic C. Microbial turnover rates are also thought to be impacted by environmental factors, but rarely have been directly measured so far. Here, we aimed at determining the short-term effects of environmental factors (soil temperature and soil moisture) on microbial CUE and microbial biomass turnover rates based on the novel 18O approach. Soils from three land-use types (arable

  2. Root biomass in cereals, catch crops and weeds can be reliably estimated without considering aboveground biomass

    DEFF Research Database (Denmark)

    Hu, Teng; Sørensen, Peter; Wahlström, Ellen Margrethe

    2018-01-01

    and management factors may affect this allometric relationship making such estimates uncertain and biased. Therefore, we aimed to explore how root biomass for typical cereal crops, catch crops and weeds could most reliably be estimated. Published and unpublished data on aboveground and root biomass (corrected...

  3. Standard filtration practices may significantly distort planktonic microbial diversity estimates

    Directory of Open Access Journals (Sweden)

    Cory Cruz Padilla

    2015-06-01

    Full Text Available Fractionation of biomass by filtration is a standard method for sampling planktonic microbes. It is unclear how the taxonomic composition of filtered biomass changes depending on sample volume. Using seawater from a marine oxygen minimum zone, we quantified the 16S rRNA gene composition of biomass on a prefilter (1.6 μm pore-size and a downstream 0.2 μm filter over sample volumes from 0.05 to 5 L. Significant community shifts occurred in both filter fractions, and were most dramatic in the prefilter community. Sequences matching Vibrionales decreased from ~40-60% of prefilter datasets at low volumes (0.05-0.5 L to less than 5% at higher volumes, while groups such at the Chromatiales and Thiohalorhabdales followed opposite trends, increasing from minor representation to become the dominant taxa at higher volumes. Groups often associated with marine particles, including members of the Deltaproteobacteria, Planctomycetes and Bacteroidetes, were among those showing the greatest increase with volume (4 to 27-fold. Taxon richness (97% similarity clusters also varied significantly with volume, and in opposing directions depending on filter fraction, highlighting potential biases in community complexity estimates. These data raise concerns for studies using filter fractionation for quantitative comparisons of aquatic microbial diversity, for example between free-living and particle-associated communities.

  4. The weight of nations: an estimation of adult human biomass

    Directory of Open Access Journals (Sweden)

    Walpole Sarah

    2012-06-01

    Full Text Available Abstract Background The energy requirement of species at each trophic level in an ecological pyramid is a function of the number of organisms and their average mass. Regarding human populations, although considerable attention is given to estimating the number of people, much less is given to estimating average mass, despite evidence that average body mass is increasing. We estimate global human biomass, its distribution by region and the proportion of biomass due to overweight and obesity. Methods For each country we used data on body mass index (BMI and height distribution to estimate average adult body mass. We calculated total biomass as the product of population size and average body mass. We estimated the percentage of the population that is overweight (BMI > 25 and obese (BMI > 30 and the biomass due to overweight and obesity. Results In 2005, global adult human biomass was approximately 287 million tonnes, of which 15 million tonnes were due to overweight (BMI > 25, a mass equivalent to that of 242 million people of average body mass (5% of global human biomass. Biomass due to obesity was 3.5 million tonnes, the mass equivalent of 56 million people of average body mass (1.2% of human biomass. North America has 6% of the world population but 34% of biomass due to obesity. Asia has 61% of the world population but 13% of biomass due to obesity. One tonne of human biomass corresponds to approximately 12 adults in North America and 17 adults in Asia. If all countries had the BMI distribution of the USA, the increase in human biomass of 58 million tonnes would be equivalent in mass to an extra 935 million people of average body mass, and have energy requirements equivalent to that of 473 million adults. Conclusions Increasing population fatness could have the same implications for world food energy demands as an extra half a billion people living on the earth.

  5. Microbial conversion of biomass into bio-based polymers.

    Science.gov (United States)

    Kawaguchi, Hideo; Ogino, Chiaki; Kondo, Akihiko

    2017-12-01

    The worldwide market for plastics is rapidly growing, and plastics polymers are typically produced from petroleum-based chemicals. The overdependence on petroleum-based chemicals for polymer production raises economic and environmental sustainability concerns. Recent progress in metabolic engineering has expanded fermentation products from existing aliphatic acids or alcohols to include aromatic compounds. This diversity provides an opportunity to expand the development and industrial uses of high-performance bio-based polymers. However, most of the biomonomers are produced from edible sugars or starches that compete directly with food and feed uses. The present review focuses on recent progress in the microbial conversion of biomass into bio-based polymers, in which fermentative products from renewable feedstocks serve as biomonomers for the synthesis of bio-based polymers. In particular, the production of biomonomers from inedible lignocellulosic feedstocks by metabolically engineered microorganisms and the synthesis of bio-based engineered plastics from the biological resources are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. A Compilation of Global Soil Microbial Biomass Carbon, Nitrogen, and Phosphorus Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides the concentrations of soil microbial biomass carbon (C), nitrogen (N) and phosphorus (P), soil organic carbon, total nitrogen, and total...

  7. Bioaugmentation for Electricity Generation from Corn Stover Biomass Using Microbial Fuel Cells

    KAUST Repository

    Wang, Xin; Feng, Yujie; Wang, Heming; Qu, Youpeng; Yu, Yanling; Ren, Nanqi; Li, Nan; Wang, Elle; Lee, He; Logan, Bruce E.

    2009-01-01

    of microbial consortia specifically acclimated for biomass breakdown. A mixed culture that was developed to have a high saccharification rate with corn stover was added to singlechamber, air-cathode MFCs acclimated for power production using glucose. The MFC

  8. Microbial Biomass Changes during Decomposition of Plant Residues in a Lixisol

    Directory of Open Access Journals (Sweden)

    Kachaka, SK.

    2003-01-01

    Full Text Available A lixisol was amended with four different alley cropping species: Senna siamea, Leucaena leucocephala, Dactyladenia barteri and Flemingia macrophylla. Soil samples were incubated for 140 days at 25 °C and the soil microbial biomass was determined by the ninhydrin extraction method along the incubation period. The soil microbial biomass values ranged between 80 and 600 mg.kg-1 and followed, in all cases, the decreasing order: Leucaena> Senna> Flemingia> Dactyladenia.

  9. Assimilable organic carbon (AOC in soil water extracts using Vibrio harveyi BB721 and its implication for microbial biomass.

    Directory of Open Access Journals (Sweden)

    Jincai Ma

    Full Text Available Assimilable organic carbon (AOC is commonly used to measure the growth potential of microorganisms in water, but has not yet been investigated for measuring microbial growth potential in soils. In this study, a simple, rapid, and non-growth based assay to determine AOC in soil was developed using a naturally occurring luminous strain Vibrio harveyi BB721 to determine the fraction of low molecular weight organic carbon in soil water extract. Calibration of the assay was achieved by measuring the luminescence intensity of starved V. harveyi BB721 cells in the late exponential phase with a concentration range from 0 to 800 µg l(-1 glucose (equivalent to 0-16.0 mg glucose C kg(-1 soil with the detection limit of 10 µg l(-1 equivalent to 0.20 mg glucose C kg(-1 soil. Results showed that bioluminescence was proportional to the concentration of glucose added to soil. The luminescence intensity of the cells was highly pH dependent and the optimal pH was about 7.0. The average AOC concentration in 32 soils tested was 2.9±2.2 mg glucose C kg(-1. Our data showed that AOC levels in soil water extracts were significantly correlated (P<0.05 with microbial biomass determined as microbial biomass carbon, indicating that the AOC concentrations determined by the method developed might be a good indicator of soil microbial biomass. Our findings provide a new approach that may be used to determine AOC in environmental samples using a non-growth bioluminescence based assay. Understanding the levels of AOC in soil water extract provides new insights into our ability to estimate the most available carbon pool to bacteria in soil that may be easily assimilated into cells for many metabolic processes and suggest possible the links between AOC, microbial regrowth potential, and microbial biomass in soils.

  10. MODIS Based Estimation of Forest Aboveground Biomass in China

    Science.gov (United States)

    Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

    2015-01-01

    Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha−1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y−1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y−1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y−1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests. PMID:26115195

  11. MODIS Based Estimation of Forest Aboveground Biomass in China.

    Science.gov (United States)

    Yin, Guodong; Zhang, Yuan; Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

    2015-01-01

    Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha-1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y-1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y-1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y-1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests.

  12. MODIS Based Estimation of Forest Aboveground Biomass in China.

    Directory of Open Access Journals (Sweden)

    Guodong Yin

    Full Text Available Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS dataset in a machine learning algorithm (the model tree ensemble, MTE. We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha-1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y-1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y-1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y-1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests.

  13. Sampling strategies for efficient estimation of tree foliage biomass

    Science.gov (United States)

    Hailemariam Temesgen; Vicente Monleon; Aaron Weiskittel; Duncan Wilson

    2011-01-01

    Conifer crowns can be highly variable both within and between trees, particularly with respect to foliage biomass and leaf area. A variety of sampling schemes have been used to estimate biomass and leaf area at the individual tree and stand scales. Rarely has the effectiveness of these sampling schemes been compared across stands or even across species. In addition,...

  14. Tree height and tropical forest biomass estimation

    Science.gov (United States)

    M.O. Hunter; M. Keller; D. Vitoria; D.C. Morton

    2013-01-01

    Tropical forests account for approximately half of above-ground carbon stored in global vegetation. However, uncertainties in tropical forest carbon stocks remain high because it is costly and laborious to quantify standing carbon stocks. Carbon stocks of tropical forests are determined using allometric relations between tree stem diameter and height and biomass....

  15. Microbial biomass carbon and enzyme activities of urban soils in Beijing.

    Science.gov (United States)

    Wang, Meie; Markert, Bernd; Shen, Wenming; Chen, Weiping; Peng, Chi; Ouyang, Zhiyun

    2011-07-01

    To promote rational and sustainable use of soil resources and to maintain the urban soil quality, it is essential to assess urban ecosystem health. In this study, the microbiological properties of urban soils in Beijing and their spatial distribution patterns across the city were evaluated based on measurements of microbial biomass carbon and urease and invertase activities of the soils for the purpose of assessing the urban ecosystem health of Beijing. Grid sampling design, normal Kriging technique, and the multiple comparisons among different land use types were used in soil sampling and data treatment. The inherent chemical characteristics of urban soils in Beijing, e.g., soil pH, electronic conductivity, heavy metal contents, total N, P and K contents, and soil organic matter contents were detected. The size and diversity of microbial community and the extent of microbial activity in Beijing urban soils were measured as the microbial biomass carbon content and the ratio of microbial biomass carbon content to total soil organic carbon. The microbial community health measured in terms of microbial biomass carbon, urease, and invertase activities varied with the organic substrate and nutrient contents of the soils and were not adversely affected by the presence of heavy metals at p urban soils influenced the nature and activities of the microbial communities.

  16. Biomass models to estimate carbon stocks for hardwood tree species

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Peinado, R.; Montero, G.; Rio, M. del

    2012-11-01

    To estimate forest carbon pools from forest inventories it is necessary to have biomass models or biomass expansion factors. In this study, tree biomass models were developed for the main hardwood forest species in Spain: Alnus glutinosa, Castanea sativa, Ceratonia siliqua, Eucalyptus globulus, Fagus sylvatica, Fraxinus angustifolia, Olea europaea var. sylvestris, Populus x euramericana, Quercus canariensis, Quercus faginea, Quercus ilex, Quercus pyrenaica and Quercus suber. Different tree biomass components were considered: stem with bark, branches of different sizes, above and belowground biomass. For each species, a system of equations was fitted using seemingly unrelated regression, fulfilling the additivity property between biomass components. Diameter and total height were explored as independent variables. All models included tree diameter whereas for the majority of species, total height was only considered in the stem biomass models and in some of the branch models. The comparison of the new biomass models with previous models fitted separately for each tree component indicated an improvement in the accuracy of the models. A mean reduction of 20% in the root mean square error and a mean increase in the model efficiency of 7% in comparison with recently published models. So, the fitted models allow estimating more accurately the biomass stock in hardwood species from the Spanish National Forest Inventory data. (Author) 45 refs.

  17. Tropical forest biomass estimation from truncated stand tables.

    Science.gov (United States)

    A. J. R. Gillespie; S. Brown; A. E. Lugo

    1992-01-01

    Total aboveground forest biomass may be estimated through a variety of techniques based on commercial inventory stand and stock tables. Stand and stock tables from tropical countries commonly omit trees bellow a certain commercial limit.

  18. Ambient ultraviolet radiation in the Arctic reduces root biomass and alters microbial community composition but has no effects on microbial biomass

    DEFF Research Database (Denmark)

    Rinnan, R.; Keinänen, M.M.; Kasurinen, A.

    2005-01-01

    We assessed the effects of ambient solar ultraviolet (UV) radiation on below-ground parameters in an arctic heath in north-eastern Greenland. We hypothesized that the current UV fluxes would reduce root biomass and mycorrhizal colonization and that these changes would lead to lower soil microbial...... biomass and altered microbial community composition. These hypotheses were tested on cored soil samples from a UV reduction experiment with three filter treatments (Mylar, 60% UV-B reduction; Lexan, up to 90% UV-B reduction+UV-A reduction; UV transparent Teflon, filter control) and an open control...... treatment in two study sites after 3 years' manipulation. Reduction of both UV-A and UV-B radiation caused over 30% increase in the root biomass of Vaccinium uliginosum, which was the dominant plant species. UV reduction had contrasting effects on ericoid mycorrhizal colonization of V. uliginosum roots...

  19. Alterations in soil microbial community composition and biomass following agricultural land use change.

    Science.gov (United States)

    Zhang, Qian; Wu, Junjun; Yang, Fan; Lei, Yao; Zhang, Quanfa; Cheng, Xiaoli

    2016-11-04

    The effect of agricultural land use change on soil microbial community composition and biomass remains a widely debated topic. Here, we investigated soil microbial community composition and biomass [e.g., bacteria (B), fungi (F), Arbuscular mycorrhizal fungi (AMF) and Actinomycete (ACT)] using phospholipid fatty acids (PLFAs) analysis, and basal microbial respiration in afforested, cropland and adjacent uncultivated soils in central China. We also investigated soil organic carbon and nitrogen (SOC and SON), labile carbon and nitrogen (LC and LN), recalcitrant carbon and nitrogen (RC and RN), pH, moisture, and temperature. Afforestation averaged higher microbial PLFA biomass compared with cropland and uncultivated soils with higher values in top soils than deep soils. The microbial PLFA biomass was strongly correlated with SON and LC. Higher SOC, SON, LC, LN, moisture and lower pH in afforested soils could be explained approximately 87.3% of total variation of higher total PLFAs. Afforestation also enhanced the F: B ratios compared with cropland. The basal microbial respiration was higher while the basal microbial respiration on a per-unit-PLFA basis was lower in afforested land than adjacent cropland and uncultivated land, suggesting afforestation may increase soil C utilization efficiency and decrease respiration loss in afforested soils.

  20. [Effects of altitudes on soil microbial biomass and enzyme activity in alpine-gorge regions.

    Science.gov (United States)

    Cao, Rui; Wu, Fu Zhong; Yang, Wan Qin; Xu, Zhen Feng; Tani, Bo; Wang, Bin; Li, Jun; Chang, Chen Hui

    2016-04-22

    In order to understand the variations of soil microbial biomass and soil enzyme activities with the change of altitude, a field incubation was conducted in dry valley, ecotone between dry valley and mountain forest, subalpine coniferous forest, alpine forest and alpine meadow from 1563 m to 3994 m of altitude in the alpine-gorge region of western Sichuan. The microbial biomass carbon and nitrogen, and the activities of invertase, urease and acid phosphorus were measured in both soil organic layer and mineral soil layer. Both the soil microbial biomass and soil enzyme activities showed the similar tendency in soil organic layer. They increased from 2158 m to 3028 m, then decreased to the lowest value at 3593 m, and thereafter increased until 3994 m in the alpine-gorge region. In contrast, the soil microbial biomass and soil enzyme activities in mineral soil layer showed the trends as, the subalpine forest at 3028 m > alpine meadow at 3994 m > montane forest ecotone at 2158 m > alpine forest at 3593 m > dry valley at 1563 m. Regardless of altitudes, soil microbial biomass and soil enzyme activities were significantly higher in soil organic layer than in mineral soil layer. The soil microbial biomass was significantly positively correlated with the activities of the measured soil enzymes. Moreover, both the soil microbial biomass and soil enzyme activities were significantly positively correlated with soil water content, organic carbon, and total nitrogen. The activity of soil invertase was significantly positively correlated with soil phosphorus content, and the soil acid phosphatase was so with soil phosphorus content and soil temperature. In brief, changes in vegetation and other environmental factors resulting from altitude change might have strong effects on soil biochemical properties in the alpine-gorge region.

  1. Canada's forest biomass resources: deriving estimates from Canada's forest inventory

    International Nuclear Information System (INIS)

    Penner, M.; Power, K.; Muhairwe, C.; Tellier, R.; Wang, Y.

    1997-01-01

    A biomass inventory for Canada was undertaken to address the data needs of carbon budget modelers, specifically to provide estimates of above-ground tree components and of non-merchantable trees in Canadian forests. The objective was to produce a national method for converting volume estimates to biomass that was standardized, repeatable across the country, efficient and well documented. Different conversion methods were used for low productivity forests (productivity class 1) and higher productivity forests (productivity class 2). The conversion factors were computed by constructing hypothetical stands for each site, age, species and province combination, and estimating the merchantable volume and all the above-ground biomass components from suitable published equations. This report documents the procedures for deriving the national biomass inventory, and provides illustrative examples of the results. 46 refs., 9 tabs., 5 figs

  2. DUE GlobBiomass - Estimates of Biomass on a Global Scale

    Science.gov (United States)

    Eberle, J.; Schmullius, C.

    2017-12-01

    For the last three years, a new ESA Data User Element (DUE) project had focussed on creating improved knowledge about the Essential Climate Variable Biomass. The main purpose of the DUE GlobBiomass project is to better characterize and to reduce uncertainties of AGB estimates by developing an innovative synergistic mapping approach in five regional sites (Sweden, Poland, Mexico, Kalimantan, South Africa) for the epochs 2005, 2010 and 2015 and for one global map for the year 2010. The project team includes leading Earth Observation experts of Europe and is linked through Partnership Agreements with further national bodies from Brazil, Canada, China, Russia and South Africa. GlobBiomass has demonstrated how EO observation data can be integrated with in situ measurements and ecological understanding to provide improved biomass estimates that can be effectively exploited by users. The target users had mainly be drawn from the climate and carbon cycle modelling communities and included users concerned with carbon emissions and uptake due to biomass changes within initiatives such as REDD+. GlobBiomass provided a harmonised structure that can be exploited to address user needs for biomass information, but will be capable of being progressively refined as new data and methods become available. This presentation will give an overview of the technical prerequisites and final results of the GlobBiomass project.

  3. Estimates of global cyanobacterial biomass and its distribution

    Science.gov (United States)

    Garcia-Pichel, Ferran; Belnap, Jayne; Neuer, Susanne; Schanz, Ferdinand

    2003-01-01

    We estimated global cyanobacterial biomass in the main reservoirs of cyanobacteria on Earth: marine and freshwater plankton, arid land soil crusts, and endoliths. Estimates were based on typical population density values as measured during our research, or as obtained from literature surveys, which were then coupled with data on global geographical area coverage. Among the marine plankton, the global biomass of Prochlorococcus reaches 120 × 1012 grams of carbon (g C), and that of Synechoccus some 43 × 1012 g C. This makes Prochlorococcus and Synechococcus, in that order, the most abundant cyanobacteria on Earth. Tropical marine blooms of Trichodesmium account for an additional 10 × 1012 g C worldwide. In terrestrial environments, the mass of cyanobacteria in arid land soil crusts is estimated to reach 54 × 1012 g C and that of arid land endolithic communities an additional 14 × 1012 g C. The global biomass of planktic cyanobacteria in lakes is estimated to be around 3 × 1012 g C. Our conservative estimates, which did not include some potentially significant biomass reservoirs such as polar and subarctic areas, topsoils in subhumid climates, and shallow marine and freshwater benthos, indicate that the total global cyanobacterial biomass is in the order of 3 × 1014 g C, surpassing a thousand million metric tons (1015 g) of wet biomass.

  4. On-line Biomass Estimation in a Batch Biotechnological Process: Bacillus thuringiensis δ - endotoxins production.

    OpenAIRE

    Amicarelli, Adriana

    2010-01-01

    In this Chapter it has been addressed the problem of the biomass estimation in a batch biotechnological process: the Bacillus thuringiensis (Bt) δ-endotoxins production process. Different alternatives that can be successfully used in this sense were presented. It has been exposed the design of various biomass estimators, namely: a phenomenological biomass estimator, a standard EKF biomass estimator, a biomass estimator based on ANN, a decentralized Kalman Filter, and a biomass concentration ...

  5. Evaluation of sampling strategies to estimate crown biomass

    Directory of Open Access Journals (Sweden)

    Krishna P Poudel

    2015-01-01

    Full Text Available Background Depending on tree and site characteristics crown biomass accounts for a significant portion of the total aboveground biomass in the tree. Crown biomass estimation is useful for different purposes including evaluating the economic feasibility of crown utilization for energy production or forest products, fuel load assessments and fire management strategies, and wildfire modeling. However, crown biomass is difficult to predict because of the variability within and among species and sites. Thus the allometric equations used for predicting crown biomass should be based on data collected with precise and unbiased sampling strategies. In this study, we evaluate the performance different sampling strategies to estimate crown biomass and to evaluate the effect of sample size in estimating crown biomass. Methods Using data collected from 20 destructively sampled trees, we evaluated 11 different sampling strategies using six evaluation statistics: bias, relative bias, root mean square error (RMSE, relative RMSE, amount of biomass sampled, and relative biomass sampled. We also evaluated the performance of the selected sampling strategies when different numbers of branches (3, 6, 9, and 12 are selected from each tree. Tree specific log linear model with branch diameter and branch length as covariates was used to obtain individual branch biomass. Results Compared to all other methods stratified sampling with probability proportional to size estimation technique produced better results when three or six branches per tree were sampled. However, the systematic sampling with ratio estimation technique was the best when at least nine branches per tree were sampled. Under the stratified sampling strategy, selecting unequal number of branches per stratum produced approximately similar results to simple random sampling, but it further decreased RMSE when information on branch diameter is used in the design and estimation phases. Conclusions Use of

  6. Evaluation of SPOT imagery for the estimation of grassland biomass

    Science.gov (United States)

    Dusseux, P.; Hubert-Moy, L.; Corpetti, T.; Vertès, F.

    2015-06-01

    In many regions, a decrease in grasslands and change in their management, which are associated with agricultural intensification, have been observed in the last half-century. Such changes in agricultural practices have caused negative environmental effects that include water pollution, soil degradation and biodiversity loss. Moreover, climate-driven changes in grassland productivity could have serious consequences for the profitability of agriculture. The aim of this study was to assess the ability of remotely sensed data with high spatial resolution to estimate grassland biomass in agricultural areas. A vegetation index, namely the Normalized Difference Vegetation Index (NDVI), and two biophysical variables, the Leaf Area Index (LAI) and the fraction of Vegetation Cover (fCOVER) were computed using five SPOT images acquired during the growing season. In parallel, ground-based information on grassland growth was collected to calculate biomass values. The analysis of the relationship between the variables derived from the remotely sensed data and the biomass observed in the field shows that LAI outperforms NDVI and fCOVER to estimate biomass (R2 values of 0.68 against 0.30 and 0.50, respectively). The squared Pearson correlation coefficient between observed and estimated biomass using LAI derived from SPOT images reached 0.73. Biomass maps generated from remotely sensed data were then used to estimate grass reserves at the farm scale in the perspective of operational monitoring and forecasting.

  7. Secondary Forest Age and Tropical Forest Biomass Estimation Using TM

    Science.gov (United States)

    Nelson, R. F.; Kimes, D. S.; Salas, W. A.; Routhier, M.

    1999-01-01

    The age of secondary forests in the Amazon will become more critical with respect to the estimation of biomass and carbon budgets as tropical forest conversion continues. Multitemporal Thematic Mapper data were used to develop land cover histories for a 33,000 Square kM area near Ariquemes, Rondonia over a 7 year period from 1989-1995. The age of the secondary forest, a surrogate for the amount of biomass (or carbon) stored above-ground, was found to be unimportant in terms of biomass budget error rates in a forested TM scene which had undergone a 20% conversion to nonforest/agricultural cover types. In such a situation, the 80% of the scene still covered by primary forest accounted for over 98% of the scene biomass. The difference between secondary forest biomass estimates developed with and without age information were inconsequential relative to the estimate of biomass for the entire scene. However, in futuristic scenarios where all of the primary forest has been converted to agriculture and secondary forest (55% and 42% respectively), the ability to age secondary forest becomes critical. Depending on biomass accumulation rate assumptions, scene biomass budget errors on the order of -10% to +30% are likely if the age of the secondary forests are not taken into account. Single-date TM imagery cannot be used to accurately age secondary forests into single-year classes. A neural network utilizing TM band 2 and three TM spectral-texture measures (bands 3 and 5) predicted secondary forest age over a range of 0-7 years with an RMSE of 1.59 years and an R(Squared) (sub actual vs predicted) = 0.37. A proposal is made, based on a literature review, to use satellite imagery to identify general secondary forest age groups which, within group, exhibit relatively constant biomass accumulation rates.

  8. Production of microbial biomass protein by sequential culture fermentation of Arachniotus sp., and Candida utilis

    International Nuclear Information System (INIS)

    Ahmed, S.; Ahmad, F.; Hashmi, A.S.

    2010-01-01

    Sequential culture fermentation by Arachniotus sp. at 35 deg. C for 72 h and followed by Candida utilis fermentation at 35 deg. C for 72 h more resulted in higher production of microbial biomass protein. 6% (w/v) corn stover, 0.0075% CaCl/sub 2/.2H/sub 2/O, 0.005% MgSO/sub 4/.7H/sub 2/O, 0.01% KH/sub 2/PO/sub 4/, C:N ratio of 30:1 and 1% molasses gave higher microbial biomass protein production by the sequential culture fermentation of Arachniotus sp., and C. utilis. The mixed microbial biomass protein produced in the 75-L fermentor contained 16.41%, 23.51%, 10.9%, 12.11% and 0.12% true protein, crude protein, crude fiber, ash and RNA content, respectively. The amino acid profile of final mixed microbial biomass protein showed that it was enriched with essential amino acids. Thus, the potential utilization of corn stover can minimize the cost for growth of these microorganisms and enhance microbial biomass protein production by sequential culture fermentation. (author)

  9. [Effects of bio-crust on soil microbial biomass and enzyme activities in copper mine tailings].

    Science.gov (United States)

    Chen, Zheng; Yang, Gui-de; Sun, Qing-ye

    2009-09-01

    Bio-crust is the initial stage of natural primary succession in copper mine tailings. With the Yangshanchong and Tongguanshan copper mine tailings in Tongling City of Anhui Province as test objects, this paper studied the soil microbial biomass C and N and the activities of dehydrogenase, catalase, alkaline phosphatase, and urease under different types of bio-crust. The bio-crusts improved the soil microbial biomass and enzyme activities in the upper layer of the tailings markedly. Algal crust had the best effect in improving soil microbial biomass C and N, followed by moss-algal crust, and moss crust. Soil microflora also varied with the type of bio-crust. No'significant difference was observed in the soil enzyme activities under the three types of bio-crust. Soil alkaline phosphatase activity was significantly positively correlated with soil microbial biomass and dehydrogenase and urease activities, but negatively correlated with soil pH. In addition, moss rhizoid could markedly enhance the soil microbial biomass and enzyme activities in moss crust rhizoid.

  10. Changes in Soil Enzyme Activities and Microbial Biomass after Revegetation in the Three Gorges Reservoir, China

    Directory of Open Access Journals (Sweden)

    Qingshui Ren

    2018-05-01

    Full Text Available Soil enzymes and microbes are central to the decomposition of plant and microbial detritus, and play important roles in carbon, nitrogen, and phosphorus biogeochemistry cycling at the ecosystem level. In the present study, we characterized the soil enzyme activity and microbial biomass in revegetated (with Taxodium distichum (L. Rich. and Cynodon dactylon (L. Pers. versus unplanted soil in the riparian zone of the Three Gorges Dam Reservoir (TGDR, in order to quantify the effect of revegetation on the edaphic microenvironment after water flooding in situ. After revegetation, the soil physical and chemical properties in revegetated soil showed significant differences to those in unplanted soil. The microbial biomass carbon and phosphorus in soils of T. distichum were significantly higher than those in C. dactylon and unplanted soils, respectively. The microbial biomass nitrogen in revegetated T. distichum and C. dactylon soils was significantly increased by 273% and 203%, respectively. The enzyme activities of T. distichum and C. dactylon soils displayed no significant difference between each other, but exhibited a great increase compared to those of the unplanted soil. Elements ratio (except C/N (S did not vary significantly between T. distichum and C. dactylon soils; meanwhile, a strong community-level elemental homeostasis in the revegetated soils was found. The correlation analyses demonstrated that only microbial biomass carbon and phosphorus had a significantly positive relationship with soil enzyme activities. After revegetation, both soil enzyme activities and microbial biomasses were relatively stable in the T. distichum and C. dactylon soils, with the wooded soil being more superior. The higher enzyme activities and microbial biomasses demonstrate the C, N, and P cycling and the maintenance of soil quality in the riparian zone of the TGDR.

  11. Estimating forest biomass and volume using airborne laser data

    Science.gov (United States)

    Nelson, Ross; Krabill, William; Tonelli, John

    1988-01-01

    An airborne pulsed laser system was used to obtain canopy height data over a southern pine forest in Georgia in order to predict ground-measured forest biomass and timber volume. Although biomass and volume estimates obtained from the laser data were variable when compared with the corresponding ground measurements site by site, the present models are found to predict mean total tree volume within 2.6 percent of the ground value, and mean biomass within 2.0 percent. The results indicate that species stratification did not consistently improve regression relationships for four southern pine species.

  12. Microbial biomass in compost during colonization of Agaricus bisporus

    NARCIS (Netherlands)

    Vos, Aurin M.; Heijboer, Amber; Boschker, Henricus T.S.; Bonnet, Barbara; Lugones, Luis G.; Wösten, Han A.B.

    2017-01-01

    Agaricus bisporus mushrooms are commercially produced on a microbe rich compost. Here, fungal and bacterial biomass was quantified in compost with and without colonization by A. bisporus. Chitin content, indicative of total fungal biomass, increased during a 26-day period from 576 to 779 nmol

  13. Use of GIS for estimating potential and actual forest biomass for continental South and Southeast Asia.

    Science.gov (United States)

    L. R. Iverson; S. Brown; A. Prasad; H. Mitasova; A. J. R. Gillespie; A. E. Lugo

    1994-01-01

    A geographic information system (GIS) was used to estimate total biomass and biomass density of the tropical forest in south and southeast Asia because available data from forest inventories were insufficient to extrapolate biomass-density estimates across the region.

  14. Estimating patterns in Spartina alterniflora belowground biomass within salt marshes

    Science.gov (United States)

    O'Connell, J. L.; Mishra, D. R.; Alber, M.; Byrd, K. B.

    2017-12-01

    Belowground biomass of marsh plants, such as Spartina alterniflora, help prevent marsh loss because they promote soil accretion, stabilize soils and add organic matter. However, site-wide estimates of belowground biomass are difficult to obtain because root:shoot ratios vary considerably both within species and across sites. We are working to develop a data fusion tool that can predict key characteristics of S. alterniflora, including belowground biomass and plant canopy N, based on satellite imagery. We used field observations from four salt marsh locations along the Georgia Coast, including one that is studied as part of the Georgia Coastal Ecosystems LTER project. From field and remote-sensing data, we developed a hybrid modeling approach to estimate % foliar N (a surrogate for plant assimilated nutrients). Partial Least squares (PLS) regression analysis of Landsat-8 spectral bands could predict variation in foliar N and belowground biomass, suggesting this public data source might be utilized for site-wide assessment of plant biophysical variables in salt marshes. Spectrally estimated foliar N and aboveground biomass were associated with belowground biomass and root:shoot ratio in S. alterniflora. This mirrors results from a previous study from the Sacramento-San Joaquin Delta, CA, on Scheonoplectus acutus, a marsh plant found in some tidal freshwater marshes. Therefore remote sensing may be a useful tool for measuring whole plant productivity among multiple coastal marsh species.

  15. [Fungal biomass estimation in soils from southwestern Buenos Aires province (Argentina) using calcofluor white stain].

    Science.gov (United States)

    Vázquez, María B; Amodeo, Martín R; Bianchinotti, María V

    Soil microorganisms are vital for ecosystem functioning because of the role they play in soil nutrient cycling. Agricultural practices and the intensification of land use have a negative effect on microbial activities and fungal biomass has been widely used as an indicator of soil health. The aim of this study was to analyze fungal biomass in soils from southwestern Buenos Aires province using direct fluorescent staining and to contribute to its use as an indicator of environmental changes in the ecosystem as well as to define its sensitivity to weather conditions. Soil samples were collected during two consecutive years. Soil smears were prepared and stained with two different concentrations of calcofluor, and the fungal biomass was estimated under an epifluorescence microscope. Soil fungal biomass varied between 2.23 and 26.89μg fungal C/g soil, being these values in the range expected for the studied soil type. The fungal biomass was positively related to temperature and precipitations. The methodology used was reliable, standardized and sensitive to weather conditions. The results of this study contribute information to evaluate fungal biomass in different soil types and support its use as an indicator of soil health for analyzing the impact of different agricultural practices. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Microbial biomass in faeces of dairy cows affected by a nitrogen deficient diet.

    Science.gov (United States)

    Jost, Daphne Isabel; Aschemann, Martina; Lebzien, Peter; Joergensen, Rainer Georg; Sundrum, Albert

    2013-04-01

    Since more than half of the faecal nitrogen (N) originates from microbial N, the objective of the study was to develop a method for quantitatively detecting microbial biomass and portion of living microorganisms in dairy cattle faeces, including bacteria, fungi and archaea. Three techniques were tested: (1) the chloroform fumigation extraction (CFE) method, (2) detection of the fungal cell-membrane component ergosterol and (3) analysis of the cell wall components fungal glucosamine and bacterial muramic acid. In a second step, an N deficient (ND) and an N balanced (NB) diets were compared with respect to the impacts on faecal C and N fractions, microbial indices and digestibility. The mean values of microbial biomass C and N concentrations averaged around 37 and 4.9 mg g(-1) DM, respectively. Ergosterol, together with fungal glucosamine and bacterial muramic acid, revealed a 25% fungal C in relation to the total microbial C content in dairy cattle faeces. Changes in ruminal N supply showed significant effects on faecal composition. Faecal concentrations of NDF, hemicelluloses and undigested dietary N and the total C/N ratio were significantly higher in ND treatment compared to the NB treatment. N deficiency was reflected also by a higher microbial biomass C/N ratio. It was concluded that the assessment of microbial indices provides valuable information with respect to diet effects on faecal composition and the successive decomposition. Further studies should be conducted to explore the potentials for minimising nutrient losses from faeces.

  17. Forest wildfire increases soil microbial biomass C:N:P stoichiometry in long-term effects

    Science.gov (United States)

    Zhou, Xuan

    2017-04-01

    Boreal forest fire strongly influences carbon (C) stock in permafrost soil by thawing permafrost table which accelerated microbe decomposition process. We studied soil microbial biomass stoichiometry in a gradient of four (3 yr, 25 yr, 46 yr and more than 100 yr) ages since fire in Canada boreal forest. Soil microbial biomass (MB) in long-term after fire is significantly higher than in short-term. MB C and nitrogen (N) were mainly dominated by corresponding soil element concentration and inorganic P, while MB phosphorus (P) changes were fully explained by soil N. Fire ages and soil temperature positively increased MB N and P, indicating the negative impact by fire. Microbial C:N:P gradually increased with fire ages from 15:2:1 to 76:6:1 and then drop down to 17:2:1 in the oldest fire ages. The degree of homeostasis of microbial C, N and P are close to 1 indicates non-homoeostasis within microbial elements, while it of C:N:P is close to 8 shows a strong homeostasis within element ratios and proved microbial stoichiometric ratio is not driven by soil element ratios. In conclusion, i) microbial biomass elements highly depends on soil nutrient supply rather than fire ages; ii) wildfire decreased microbial stoichiometry immediate after fire but increased with years after fire (YF) which at least 3 times higher than > 100 fire ages; iii) microbial biomass C, N and P deviated from strict homeostasis but C:N:P ratio reflects stronger homeostasis.

  18. Application of next-generation sequencing methods for microbial monitoring of anaerobic digestion of lignocellulosic biomass.

    Science.gov (United States)

    Bozan, Mahir; Akyol, Çağrı; Ince, Orhan; Aydin, Sevcan; Ince, Bahar

    2017-09-01

    The anaerobic digestion of lignocellulosic wastes is considered an efficient method for managing the world's energy shortages and resolving contemporary environmental problems. However, the recalcitrance of lignocellulosic biomass represents a barrier to maximizing biogas production. The purpose of this review is to examine the extent to which sequencing methods can be employed to monitor such biofuel conversion processes. From a microbial perspective, we present a detailed insight into anaerobic digesters that utilize lignocellulosic biomass and discuss some benefits and disadvantages associated with the microbial sequencing techniques that are typically applied. We further evaluate the extent to which a hybrid approach incorporating a variation of existing methods can be utilized to develop a more in-depth understanding of microbial communities. It is hoped that this deeper knowledge will enhance the reliability and extent of research findings with the end objective of improving the stability of anaerobic digesters that manage lignocellulosic biomass.

  19. Assessment of microbial activity and biomass in different soils exposed to nicosulfuron

    Directory of Open Access Journals (Sweden)

    Ljiljana Šantrić

    2014-09-01

    Full Text Available The effects of the herbicide nicosulfuron on the abundance of cellulolytic and proteolytic microorganisms, activity of β-glucosidase and protease enzymes, and microbial phosphorus biomass were examined. A laboratory bioassay was set up on two types of agricultural soils differing in physicochemical properties. The following concentrations were tested: 0.3, 0.6, 3.0 and 30.0 mg a.i./kg of soil. Samples were collected 3, 7, 14, 30 and 45 days after treatment with nicosulfuron. The results showed that nicosulfuron significantly reduced the abundance of cellulolytic microorganisms in both soils, as well as microbial biomass phosphorus in sandy loam soil. The herbicide was found to stimulate β-glucosidase and protease activity in both types of soil and microbial biomass phosphorus in loamy soil. Proteolytic microorganisms remained unaffected by nicosulfuron.

  20. Evaluating lidar point densities for effective estimation of aboveground biomass

    Science.gov (United States)

    Wu, Zhuoting; Dye, Dennis G.; Stoker, Jason M.; Vogel, John M.; Velasco, Miguel G.; Middleton, Barry R.

    2016-01-01

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) was recently established to provide airborne lidar data coverage on a national scale. As part of a broader research effort of the USGS to develop an effective remote sensing-based methodology for the creation of an operational biomass Essential Climate Variable (Biomass ECV) data product, we evaluated the performance of airborne lidar data at various pulse densities against Landsat 8 satellite imagery in estimating above ground biomass for forests and woodlands in a study area in east-central Arizona, U.S. High point density airborne lidar data, were randomly sampled to produce five lidar datasets with reduced densities ranging from 0.5 to 8 point(s)/m2, corresponding to the point density range of 3DEP to provide national lidar coverage over time. Lidar-derived aboveground biomass estimate errors showed an overall decreasing trend as lidar point density increased from 0.5 to 8 points/m2. Landsat 8-based aboveground biomass estimates produced errors larger than the lowest lidar point density of 0.5 point/m2, and therefore Landsat 8 observations alone were ineffective relative to airborne lidar for generating a Biomass ECV product, at least for the forest and woodland vegetation types of the Southwestern U.S. While a national Biomass ECV product with optimal accuracy could potentially be achieved with 3DEP data at 8 points/m2, our results indicate that even lower density lidar data could be sufficient to provide a national Biomass ECV product with accuracies significantly higher than that from Landsat observations alone.

  1. Estimation of energy potential of agricultural enterprise biomass

    Directory of Open Access Journals (Sweden)

    Lypchuk Vasyl

    2017-01-01

    Full Text Available Bioenergetics (obtaining of energy from biomass is one of innovative directions in energy branch of Ukraine. Correct and reliable estimation of biomass potential is essential for efficient use of it. The article reveals the issue of estimation of potential of biomass, obtained from byproducts of crop production and animal breeding, which can be used for power supply of agricultural enterprises. The given analysis was carried with application of common methodological fundamentals, revealed in the estimation of production structure of agricultural enterprises, structure of land employment, efficiency of crops growing, indicators of output of main and by-products, as well as normative (standard parameters of power output of energy raw material in relation to the chosen technology of its utilization. Results of the research prove high energy potential of byproducts of crop production and animal breeding at all of the studied enterprises, which should force its practical use.

  2. Microbial Functional Diversity, Biomass and Activity as Affected by Soil Surface Mulching in a Semiarid Farmland.

    Directory of Open Access Journals (Sweden)

    Yufang Shen

    Full Text Available Mulching is widely used to increase crop yield in semiarid regions in northwestern China, but little is known about the effect of different mulching systems on the microbial properties of the soil, which play an important role in agroecosystemic functioning and nutrient cycling. Based on a 4-year spring maize (Zea mays L. field experiment at Changwu Agricultural and Ecological Experimental Station, Shaanxi, we evaluated the responses of soil microbial activity and crop to various management systems. The treatments were NMC (no mulching with inorganic N fertilizer, GMC (gravel mulching with inorganic N fertilizer, FMC (plastic-film mulching with inorganic N fertilizer and FMO (plastic-film mulching with inorganic N fertilizer and organic manure addition. The results showed that the FMO soil had the highest contents of microbial biomass carbon and nitrogen, dehydrogenase activity, microbial activity and Shannon diversity index. The relative use of carbohydrates and amino acids by microbes was highest in the FMO soil, whereas the relative use of polymers, phenolic compounds and amines was highest in the soil in the NMC soil. Compared with the NMC, an increased but no significant trend of biomass production and nitrogen accumulation was observed under the GMC treatment. The FMC and FMO led a greater increase in biomass production than GMC and NMC. Compare with the NMC treatment, FMC increased grain yield, maize biomass and nitrogen accumulation by 62.2, 62.9 and 86.2%, but no significant difference was found between the FMO and FMC treatments. Some soil biological properties, i.e. microbial biomass carbon, microbial biomass nitrogen, being sensitive to the mulching and organic fertilizer, were significant correlated with yield and nitrogen availability. Film mulching over gravel mulching can serve as an effective measure for crop production and nutrient cycling, and plus organic fertilization additions may thus have improvements in the biological

  3. Tracking dynamics of plant biomass composting by changes in substrate structure, microbial community, and enzyme activity

    Directory of Open Access Journals (Sweden)

    Wei Hui

    2012-04-01

    Full Text Available Abstract Background Understanding the dynamics of the microbial communities that, along with their secreted enzymes, are involved in the natural process of biomass composting may hold the key to breaking the major bottleneck in biomass-to-biofuels conversion technology, which is the still-costly deconstruction of polymeric biomass carbohydrates to fermentable sugars. However, the complexity of both the structure of plant biomass and its counterpart microbial degradation communities makes it difficult to investigate the composting process. Results In this study, a composter was set up with a mix of yellow poplar (Liriodendron tulipifera wood-chips and mown lawn grass clippings (85:15 in dry-weight and used as a model system. The microbial rDNA abundance data obtained from analyzing weekly-withdrawn composted samples suggested population-shifts from bacteria-dominated to fungus-dominated communities. Further analyses by an array of optical microscopic, transcriptional and enzyme-activity techniques yielded correlated results, suggesting that such population shifts occurred along with early removal of hemicellulose followed by attack on the consequently uncovered cellulose as the composting progressed. Conclusion The observed shifts in dominance by representative microbial groups, along with the observed different patterns in the gene expression and enzymatic activities between cellulases, hemicellulases, and ligninases during the composting process, provide new perspectives for biomass-derived biotechnology such as consolidated bioprocessing (CBP and solid-state fermentation for the production of cellulolytic enzymes and biofuels.

  4. Tracking dynamics of plant biomass composting by changes in substrate structure, microbial community, and enzyme activity

    Science.gov (United States)

    2012-01-01

    Background Understanding the dynamics of the microbial communities that, along with their secreted enzymes, are involved in the natural process of biomass composting may hold the key to breaking the major bottleneck in biomass-to-biofuels conversion technology, which is the still-costly deconstruction of polymeric biomass carbohydrates to fermentable sugars. However, the complexity of both the structure of plant biomass and its counterpart microbial degradation communities makes it difficult to investigate the composting process. Results In this study, a composter was set up with a mix of yellow poplar (Liriodendron tulipifera) wood-chips and mown lawn grass clippings (85:15 in dry-weight) and used as a model system. The microbial rDNA abundance data obtained from analyzing weekly-withdrawn composted samples suggested population-shifts from bacteria-dominated to fungus-dominated communities. Further analyses by an array of optical microscopic, transcriptional and enzyme-activity techniques yielded correlated results, suggesting that such population shifts occurred along with early removal of hemicellulose followed by attack on the consequently uncovered cellulose as the composting progressed. Conclusion The observed shifts in dominance by representative microbial groups, along with the observed different patterns in the gene expression and enzymatic activities between cellulases, hemicellulases, and ligninases during the composting process, provide new perspectives for biomass-derived biotechnology such as consolidated bioprocessing (CBP) and solid-state fermentation for the production of cellulolytic enzymes and biofuels. PMID:22490508

  5. Hydrogen Production Cost Estimate Using Biomass Gasification: Independent Review

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, M.

    2011-10-01

    This independent review is the conclusion arrived at from data collection, document reviews, interviews and deliberation from December 2010 through April 2011 and the technical potential of Hydrogen Production Cost Estimate Using Biomass Gasification. The Panel reviewed the current H2A case (Version 2.12, Case 01D) for hydrogen production via biomass gasification and identified four principal components of hydrogen levelized cost: CapEx; feedstock costs; project financing structure; efficiency/hydrogen yield. The panel reexamined the assumptions around these components and arrived at new estimates and approaches that better reflect the current technology and business environments.

  6. Assessment of tillage systems in organic farming: influence of soil structure on microbial biomass. First results

    OpenAIRE

    Vian, Jean François; Peigné, Joséphine; Chaussod, Rémi; Roger-Estrade, Jean

    2007-01-01

    Soil tillage modifies environmental conditions of soil microorganisms and their ability to release nitrogen. We compare the influence of reduced tillage (RT) and mouldboard ploughing (MP) on the soil microbial functioning in organic farming. In order to connect soil structure generated by these tillage systems on the soil microbial biomass we adopt a particular sampling scheme based on the morphological characterisation of the soil structure by the description of the soil profile. This method...

  7. Metal impacts on microbial biomass in the anoxic sediments of a contaminated lake

    Energy Technology Data Exchange (ETDEWEB)

    Gough, Heidi L.; Dahl, Amy L.; Nolan, Melissa A.; Gaillard, Jean-Francois; Stahl, David A.

    2008-04-26

    Little is known about the long-term impacts of metal contamination on the microbiota of anoxic lake sediments. In this study, we examined microbial biomass and metals (arsenic, cadmium, chromium, copper, iron, lead, manganese, and zinc) in the sediments of Lake DePue, a backwater lake located near a former zinc smelter. Sediment core samples were examined using two independent measures for microbial biomass (total microscopic counts and total phospholipid-phosphate concentrations), and for various fractions of each metal (pore water extracts, sequential extractions, and total extracts of all studied metals and zinc speciation by X-ray absorption fine structure (XAFS). Zinc concentrations were up to 1000 times higher than reported for sediments in the adjacent Illinois River, and ranged from 21,400 mg/kg near the source to 1,680 mg/kg near the river. However, solid metal fractions were not well correlated with pore water concentrations, and were not good predictors of biomass concentrations. Instead, biomass, which varied among sites by as much as two-times, was inversely correlated with concentrations of pore water zinc and arsenic as established by multiple linear regression. Monitoring of other parameters known to naturally influence biomass in sediments (e.g., organic carbon concentrations, nitrogen concentrations, pH, sediment texture, and macrophytes) revealed no differences that could explain observed biomass trends. This study provides strong support for control of microbial abundance by pore water metal concentrations in contaminated freshwater sediments.

  8. Estimation of Boreal Forest Biomass Using Spaceborne SAR Systems

    Science.gov (United States)

    Saatchi, Sassan; Moghaddam, Mahta

    1995-01-01

    In this paper, we report on the use of a semiempirical algorithm derived from a two layer radar backscatter model for forest canopies. The model stratifies the forest canopy into crown and stem layers, separates the structural and biometric attributes of the canopy. The structural parameters are estimated by training the model with polarimetric SAR (synthetic aperture radar) data acquired over homogeneous stands with known above ground biomass. Given the structural parameters, the semi-empirical algorithm has four remaining parameters, crown biomass, stem biomass, surface soil moisture, and surface rms height that can be estimated by at least four independent SAR measurements. The algorithm has been used to generate biomass maps over the entire images acquired by JPL AIRSAR and SIR-C SAR systems. The semi-empirical algorithms are then modified to be used by single frequency radar systems such as ERS-1, JERS-1, and Radarsat. The accuracy. of biomass estimation from single channel radars is compared with the case when the channels are used together in synergism or in a polarimetric system.

  9. Methyl halide emission estimates from domestic biomass burning in Africa

    Science.gov (United States)

    Mead, M. I.; Khan, M. A. H.; White, I. R.; Nickless, G.; Shallcross, D. E.

    Inventories of methyl halide emissions from domestic burning of biomass in Africa, from 1950 to the present day and projected to 2030, have been constructed. By combining emission factors from Andreae and Merlet [2001. Emission of trace gases and aerosols from biomass burning. Global Biogeochemical Cycles 15, 955-966], the biomass burning estimates from Yevich and Logan [2003. An assessment of biofuel use and burning of agricultural waste in the developing world. Global Biogeochemical Cycles 17(4), 1095, doi:10.1029/2002GB001952] and the population data from the UN population division, the emission of methyl halides from domestic biomass usage in Africa has been estimated. Data from this study suggest that methyl halide emissions from domestic biomass burning have increased by a factor of 4-5 from 1950 to 2005 and based on the expected population growth could double over the next 25 years. This estimated change has a non-negligible impact on the atmospheric budgets of methyl halides.

  10. Tropical Africa: Land use, biomass, and carbon estimates for 1980

    Energy Technology Data Exchange (ETDEWEB)

    Brown, S. [Environmental Protection Agency, Corvallis, OR (United States). Western Ecology Division; Gaston, G. [Environmental Protection Agency, Corvallis, OR (United States). National Research Council; Daniels, R.C. [ed.] [Oak Ridge National Lab., TN (United States)

    1996-06-01

    This document describes the contents of a digital database containing maximum potential aboveground biomass, land use, and estimated biomass and carbon data for 1980 and describes a methodology that may be used to extend this data set to 1990 and beyond based on population and land cover data. The biomass data and carbon estimates are for woody vegetation in Tropical Africa. These data were collected to reduce the uncertainty associated with the possible magnitude of historical releases of carbon from land use change. Tropical Africa is defined here as encompassing 22.7 x 10{sup 6} km{sup 2} of the earth`s land surface and includes those countries that for the most part are located in Tropical Africa. Countries bordering the Mediterranean Sea and in southern Africa (i.e., Egypt, Libya, Tunisia, Algeria, Morocco, South Africa, Lesotho, Swaziland, and Western Sahara) have maximum potential biomass and land cover information but do not have biomass or carbon estimate. The database was developed using the GRID module in the ARC/INFO{sup TM} geographic information system. Source data were obtained from the Food and Agriculture Organization (FAO), the U.S. National Geophysical Data Center, and a limited number of biomass-carbon density case studies. These data were used to derive the maximum potential and actual (ca. 1980) aboveground biomass-carbon values at regional and country levels. The land-use data provided were derived from a vegetation map originally produced for the FAO by the International Institute of Vegetation Mapping, Toulouse, France.

  11. Planktonic food web structure at a coastal time-series site: I. Partitioning of microbial abundances and carbon biomass

    Science.gov (United States)

    Caron, David A.; Connell, Paige E.; Schaffner, Rebecca A.; Schnetzer, Astrid; Fuhrman, Jed A.; Countway, Peter D.; Kim, Diane Y.

    2017-03-01

    Biogeochemistry in marine plankton communities is strongly influenced by the activities of microbial species. Understanding the composition and dynamics of these assemblages is essential for modeling emergent community-level processes, yet few studies have examined all of the biological assemblages present in the plankton, and benchmark data of this sort from time-series studies are rare. Abundance and biomass of the entire microbial assemblage and mesozooplankton (>200 μm) were determined vertically, monthly and seasonally over a 3-year period at a coastal time-series station in the San Pedro Basin off the southwestern coast of the USA. All compartments of the planktonic community were enumerated (viruses in the femtoplankton size range [0.02-0.2 μm], bacteria + archaea and cyanobacteria in the picoplankton size range [0.2-2.0 μm], phototrophic and heterotrophic protists in the nanoplanktonic [2-20 μm] and microplanktonic [20-200 μm] size ranges, and mesozooplankton [>200 μm]. Carbon biomass of each category was estimated using standard conversion factors. Plankton abundances varied over seven orders of magnitude across all categories, and total carbon biomass averaged approximately 60 μg C l-1 in surface waters of the 890 m water column over the study period. Bacteria + archaea comprised the single largest component of biomass (>1/3 of the total), with the sum of phototrophic protistan biomass making up a similar proportion. Temporal variability at this subtropical station was not dramatic. Monthly depth-specific and depth-integrated biomass varied 2-fold at the station, while seasonal variances were generally web structure and function at this coastal observatory.

  12. Non-destructive estimation of Oecophylla smaragdina colony biomass

    DEFF Research Database (Denmark)

    Pinkalski, Christian Alexander Stidsen; Offenberg, Joachim; Jensen, Karl-Martin Vagn

    in mango plantations in Darwin, Australia. The total nest volume of O. smaragdina colonies in a tree was related to the activity of the ants (R2=0.85), estimated as the density of ant trails in the tree. Subsequently, the relation between nest volume and ant biomass (R2=0.70) was added to enable...... a prediction of ant biomass directly from ant activity. With this combined regression the ant biomass in a tree equaled 244.5 g fresh mass*ant activity. Similarly, the number of workers in trees was estimated using the relationship between nest volume and worker numbers (R2=0.84). Based on the model, five O...

  13. Extraction of solubles from plant biomass for use as microbial growth stimulant and methods related thereto

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Ming Woei

    2015-12-08

    A method for producing a microbial growth stimulant (MGS) from a plant biomass is described. In one embodiment, an ammonium hydroxide solution is used to extract a solution of proteins and ammonia from the biomass. Some of the proteins and ammonia are separated from the extracted solution to provide the MGS solution. The removed ammonia can be recycled and the proteins are useful as animal feeds. In one embodiment, the method comprises extracting solubles from pretreated lignocellulosic biomass with a cellulase enzyme-producing growth medium (such T. reesei) in the presence of water and an aqueous extract.

  14. Effects of vegetation type on microbial biomass carbon and nitrogen in subalpine mountain forest soils.

    Science.gov (United States)

    Ravindran, Anita; Yang, Shang-Shyng

    2015-08-01

    Microbial biomass plays an important role in nutrient transformation and conservation of forest and grassland ecosystems. The objective of this study was to determine the microbial biomass among three vegetation types in subalpine mountain forest soils of Taiwan. Tatachia is a typical high-altitude subalpine temperate forest ecosystem in Taiwan with an elevation of 1800-3952 m and consists of three vegetation types: spruce, hemlock, and grassland. Three plots were selected in each vegetation type. Soil samples were collected from the organic layer, topsoil, and subsoil. Microbial biomass carbon (Cmic) was determined by the chloroform fumigation-extraction method, and microbial biomass nitrogen (Nmic) was determined from the total nitrogen (Ntot) released during fumigation-extraction. Bacteria, actinomycetes, fungi, cellulolytic microbes, phosphate-solubilizing microbes, and nitrogen-fixing microbes were also counted. The Cmic and Nmic were highest in the surface soil and declined with the soil depth. These were also highest in spruce soils, followed by in hemlock soils, and were lowest in grassland soils. Cmic and Nmic had the highest values in the spring season and the lowest values in the winter season. Cmic and Nmic had significantly positive correlations with total organic carbon (Corg) and Ntot. Contributions of Cmic and Nmic, respectively, to Corg and Ntot indicated that the microbial biomass was immobilized more in spruce and hemlock soils than in grassland soils. Microbial populations of the tested vegetation types decreased with increasing soil depth. Cmic and Nmic were high in the organic layer and decreased with the depth of layers. These values were higher for spruce and hemlock soils than for grassland soils. Positive correlations were observed between Cmic and Nmic and between Corg and Ntot. Copyright © 2014. Published by Elsevier B.V.

  15. Estimating shrub biomass from basal stem diameters

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J K

    1976-01-01

    Stem lengths and oven dry wt of stemwood and foilage were determined for shrubs in dia classes of 0 to 0.5 cm, 0.5 to 2 cm and 2 to 5 cm in various habitat types in Idaho and Montana. The logarithm of basal stem dia was closely correlated with the logarithm of wt. Regression components are presented for estimating leaf wt and total above-ground wt of 25 woody shrub species using a linear equation relating these 2 variables. Percentage stemwood wt is given for the 3 dia classes. Dia distributions for the smallest dia class were normal except for a few species with fine twigs; distributions for the other classes were positively skewed. Applications to forest fuel studies are briefly discussed.

  16. Estimating shrub biomass from basal stem diameters

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J K

    1976-01-01

    Stem lengths and oven dry wt of stemwood and foilage were determined for shrubs in dia classes of 0 to 0.5 cm, 0.5 to 2 cm and 2 to 5 cm in various habitat types in Idaho and Montana. The logarithm of basal stem dia was closely correlated with the logarithm of wt. Regression components are presented for estimating leaf wt and total above-ground wt of 25 woody shrub species using a linear equation relating these 2 variables. Percentage stemwood wt is given for the 3 dia classes. Dia distributions for the smallest dia class were normal except for a few species with fine twigs: distributions for the other classes were positively skewed. Applications to forest fuel studies are briefly discussed.

  17. Trichoderma Biofertilizer Links to Altered Soil Chemistry, Altered Microbial Communities, and Improved Grassland Biomass

    Directory of Open Access Journals (Sweden)

    Fengge Zhang

    2018-04-01

    Full Text Available In grasslands, forage and livestock production results in soil nutrient deficits as grasslands typically receive no nutrient inputs, leading to a loss of grassland biomass. The application of mature compost has been shown to effectively increase grassland nutrient availability. However, research on fertilization regime influence and potential microbial ecological regulation mechanisms are rarely conducted in grassland soil. We conducted a two-year experiment in meadow steppe grasslands, focusing on above- and belowground consequences of organic or Trichoderma biofertilizer applications and potential soil microbial ecological mechanisms underlying soil chemistry and microbial community responses. Grassland biomass significantly (p = 0.019 increased following amendment with 9,000 kg ha−1 of Trichoderma biofertilizer (composted cattle manure + inoculum compared with other assessed organic or biofertilizer rates, except for BOF3000 (fertilized with 3,000 kg ha−1 biofertilizer. This rate of Trichoderma biofertilizer treatment increased soil antifungal compounds that may suppress pathogenic fungi, potentially partially responsible for improved grassland biomass. Nonmetric multidimensional scaling (NMDS revealed soil chemistry and fungal communities were all separated by different fertilization regime. Trichoderma biofertilizer (9,000 kg ha−1 increased relative abundances of Archaeorhizomyces and Trichoderma while decreasing Ophiosphaerella. Trichoderma can improve grassland biomass, while Ophiosphaerella has the opposite effect as it may secrete metabolites causing grass necrosis. Correlations between soil properties and microbial genera showed plant-available phosphorus may influence grassland biomass by increasing Archaeorhizomyces and Trichoderma while reducing Ophiosphaerella. According to our structural equation modeling (SEM, Trichoderma abundance was the primary contributor to aboveground grassland biomass. Our results suggest Trichoderma

  18. Trichoderma Biofertilizer Links to Altered Soil Chemistry, Altered Microbial Communities, and Improved Grassland Biomass.

    Science.gov (United States)

    Zhang, Fengge; Huo, Yunqian; Cobb, Adam B; Luo, Gongwen; Zhou, Jiqiong; Yang, Gaowen; Wilson, Gail W T; Zhang, Yingjun

    2018-01-01

    In grasslands, forage and livestock production results in soil nutrient deficits as grasslands typically receive no nutrient inputs, leading to a loss of grassland biomass. The application of mature compost has been shown to effectively increase grassland nutrient availability. However, research on fertilization regime influence and potential microbial ecological regulation mechanisms are rarely conducted in grassland soil. We conducted a two-year experiment in meadow steppe grasslands, focusing on above- and belowground consequences of organic or Trichoderma biofertilizer applications and potential soil microbial ecological mechanisms underlying soil chemistry and microbial community responses. Grassland biomass significantly ( p = 0.019) increased following amendment with 9,000 kg ha -1 of Trichoderma biofertilizer (composted cattle manure + inoculum) compared with other assessed organic or biofertilizer rates, except for BOF3000 (fertilized with 3,000 kg ha -1 biofertilizer). This rate of Trichoderma biofertilizer treatment increased soil antifungal compounds that may suppress pathogenic fungi, potentially partially responsible for improved grassland biomass. Nonmetric multidimensional scaling (NMDS) revealed soil chemistry and fungal communities were all separated by different fertilization regime. Trichoderma biofertilizer (9,000 kg ha -1 ) increased relative abundances of Archaeorhizomyces and Trichoderma while decreasing Ophiosphaerella . Trichoderma can improve grassland biomass, while Ophiosphaerella has the opposite effect as it may secrete metabolites causing grass necrosis. Correlations between soil properties and microbial genera showed plant-available phosphorus may influence grassland biomass by increasing Archaeorhizomyces and Trichoderma while reducing Ophiosphaerella . According to our structural equation modeling (SEM), Trichoderma abundance was the primary contributor to aboveground grassland biomass. Our results suggest Trichoderma

  19. Estimating aboveground tree biomass on forest land in the Pacific Northwest: a comparison of approaches

    Science.gov (United States)

    Xiaoping Zhou; Miles A. Hemstrom

    2009-01-01

    Live tree biomass estimates are essential for carbon accounting, bioenergy feasibility studies, and other analyses. Several models are currently used for estimating tree biomass. Each of these incorporates different calculation methods that may significantly impact the estimates of total aboveground tree biomass, merchantable biomass, and carbon pools. Consequently,...

  20. Biomass estimation in forest ecosystems - a review | Wakawa ...

    African Journals Online (AJOL)

    Forest ecosystems plays an important role in global warming serving as both sink and source of one of the prominent green house gases, carbon dioxide (CO2). Biomass estimation in forest ecosystems is an important aspect of forest management processes aimed at ensuring sustainability. The choice of appropriate ...

  1. Estimating annual bole biomass production using uncertainty analysis

    Science.gov (United States)

    Travis J. Woolley; Mark E. Harmon; Kari B. O' Connell

    2007-01-01

    Two common sampling methodologies coupled with a simple statistical model were evaluated to determine the accuracy and precision of annual bole biomass production (BBP) and inter-annual variability estimates using this type of approach. We performed an uncertainty analysis using Monte Carlo methods in conjunction with radial growth core data from trees in three Douglas...

  2. Characterization of three plant biomass-degrading microbial consortia by metagenomics- and metasecretomics-based approaches

    NARCIS (Netherlands)

    Jiménez, Diego Javier; Brossi, Maria Julia de Lima; Schuckel, Julia; Kracun, Stjepan Kresimir; Willats, William George Tycho; van Elsas, Jan Dirk

    2016-01-01

    The selection of microbes by enrichment on plant biomass has been proposed as an efficient way to develop new strategies for lignocellulose saccharification. Here, we report an in-depth analysis of soil-derived microbial consortia that were trained to degrade once-used wheat straw (WS1-M),

  3. Soil microbial biomass, activity and community composition along altitudinal gradients in the High Arctic (Billefjorden, Svalbard)

    Czech Academy of Sciences Publication Activity Database

    Kotas, P.; Šantrůčková, H.; Elster, Josef; Kaštovská, E.

    2018-01-01

    Roč. 15, č. 6 (2018), s. 1879-1894 ISSN 1726-4170 R&D Projects: GA MŠk(CZ) LM2015075 Grant - others:GA MŠk LM2010009 Institutional support: RVO:67985939 Keywords : ecosystem * High Arctic * soil microbial biomass Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 3.851, year: 2016

  4. Winter climate change affects growing-season soil microbial biomass and activity in northern hardwood forests

    Science.gov (United States)

    Jorge Durán; Jennifer L. Morse; Peter M. Groffman; John L. Campbell; Lynn M. Christenson; Charles T. Driscoll; Timothy J. Fahey; Melany C. Fisk; Myron J. Mitchell; Pamela H. Templer

    2014-01-01

    Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity...

  5. Effects of 1-Alkyl-3-Methylimidazolium Nitrate on Soil Physical and Chemical Properties and Microbial Biomass.

    Science.gov (United States)

    Zhou, Tongtong; Wang, Jun; Ma, Zhiqiang; Du, Zhongkun; Zhang, Cheng; Zhu, Lusheng; Wang, Jinhua

    2018-05-01

    Ionic liquids (ILs), also called room temperature ILs, are widely applied in many fields on the basis of their unique physical and chemical properties. However, numerous ILs may be released into and gradually accumulate in the environment due to their extensive use and absolute solubility. The effects of 1-alkyl-3-methylimidazolium nitrate ([C n mim]NO 3 , n = 4, 6, 8) on soil pH, conductivity, cation exchange capacity, microbial biomass carbon, and microbial biomass nitrogen were examined at the doses of 1, 10, and 100 mg/kg on days 10, 20, 30, and 40. The results demonstrated that the soil pH decreased and the conductivity increased with increasing IL doses. No significant differences were observed in the soil cation-exchange capacity. All three of the tested ILs decreased the soil microbial biomass carbon and nitrogen. Additionally, there were few differences among the ILs with different alkyl chain lengths on the tested indicators except for the microbial biomass nitrogen. The present study addressed a gap in the literature regarding the effects of the aforementioned ILs with different alkyl side chains on the physicochemical properties of soil, and the results could provide the basic data for future studies on their toxicity to soil organisms, such as earthworms and soil microbes.

  6. Soil microbial biomass, activity and community composition along altitudinal gradients in the High Arctic (Billefjorden, Svalbard

    Directory of Open Access Journals (Sweden)

    P. Kotas

    2018-03-01

    Full Text Available The unique and fragile High Arctic ecosystems are vulnerable to global climate warming. The elucidation of factors driving microbial distribution and activity in arctic soils is essential for a comprehensive understanding of ecosystem functioning and its response to environmental change. The goals of this study were to investigate microbial biomass and activity, microbial community structure (MCS, and their environmental controls in soils along three elevational transects in the coastal mountains of Billefjorden, central Svalbard. Soils from four different altitudes (25, 275, 525 and 765 m above sea level were analyzed for a suite of characteristics including temperature regimes, organic matter content, base cation availability, moisture, pH, potential respiration, and microbial biomass and community structure using phospholipid fatty acids (PLFAs. We observed significant spatial heterogeneity of edaphic properties among transects, resulting in transect-specific effects of altitude on most soil parameters. We did not observe any clear elevation pattern in microbial biomass, and microbial activity revealed contrasting elevational patterns between transects. We found relatively large horizontal variability in MCS (i.e., between sites of corresponding elevation in different transects, mainly due to differences in the composition of bacterial PLFAs, but also a systematic altitudinal shift in MCS related to different habitat preferences of fungi and bacteria, which resulted in high fungi-to-bacteria ratios at the most elevated sites. The biological soil crusts on these most elevated, unvegetated sites can host microbial assemblages of a size and activity comparable to those of the arctic tundra ecosystem. The key environmental factors determining horizontal and vertical changes in soil microbial properties were soil pH, organic carbon content, soil moisture and Mg2+ availability.

  7. Soil microbial biomass, activity and community composition along altitudinal gradients in the High Arctic (Billefjorden, Svalbard)

    Science.gov (United States)

    Kotas, Petr; Šantrůčková, Hana; Elster, Josef; Kaštovská, Eva

    2018-03-01

    The unique and fragile High Arctic ecosystems are vulnerable to global climate warming. The elucidation of factors driving microbial distribution and activity in arctic soils is essential for a comprehensive understanding of ecosystem functioning and its response to environmental change. The goals of this study were to investigate microbial biomass and activity, microbial community structure (MCS), and their environmental controls in soils along three elevational transects in the coastal mountains of Billefjorden, central Svalbard. Soils from four different altitudes (25, 275, 525 and 765 m above sea level) were analyzed for a suite of characteristics including temperature regimes, organic matter content, base cation availability, moisture, pH, potential respiration, and microbial biomass and community structure using phospholipid fatty acids (PLFAs). We observed significant spatial heterogeneity of edaphic properties among transects, resulting in transect-specific effects of altitude on most soil parameters. We did not observe any clear elevation pattern in microbial biomass, and microbial activity revealed contrasting elevational patterns between transects. We found relatively large horizontal variability in MCS (i.e., between sites of corresponding elevation in different transects), mainly due to differences in the composition of bacterial PLFAs, but also a systematic altitudinal shift in MCS related to different habitat preferences of fungi and bacteria, which resulted in high fungi-to-bacteria ratios at the most elevated sites. The biological soil crusts on these most elevated, unvegetated sites can host microbial assemblages of a size and activity comparable to those of the arctic tundra ecosystem. The key environmental factors determining horizontal and vertical changes in soil microbial properties were soil pH, organic carbon content, soil moisture and Mg2+ availability.

  8. Microbial biomass and activity in subsurface sediments from Vejen, Denmark

    DEFF Research Database (Denmark)

    Albrechtsen, Hans-Jørgen; Winding, Anne

    1992-01-01

    Subsurface sediment samples were collected from 4 to 31 m below landsurface in glacio-fluvial sediments from the Quaternary period. The samples were described in terms of pH, electrical conductivity, chloride concentration, organic matter content, and grain size distribution. Viable counts...... for mineralization of 14C-labelled compounds varied from 0.2 to 2.3 × 10−3 ml/(dpm · day) for acetate, and from 0 to 2.0 × 10−3 ml/(dpm · day) for phenol. Sediment texture influenced the total number of bacteria and potential for mineralization; with increasing content of clay and silt and decreasing content of sand...... a single abiotic parameter that could explain the variation of size and activity of the microbial population. The microbial data obtained in these geologically young sediments were compared to literature data from older sediments, and this comparison showed that age and type of geological formation might...

  9. Microbial Biodiesel Production by Direct Transesterification of Rhodotorula glutinis Biomass

    Directory of Open Access Journals (Sweden)

    I-Ching Kuan

    2018-04-01

    Full Text Available (1 Background: Lipids derived from oleaginous microbes have become promising alternative feedstocks for biodiesel. This is mainly because the lipid production rate from microbes is one to two orders of magnitude higher than those of energy crops. However, the conventional process for converting these lipids to biodiesel still requires a large amount of energy and organic solvents; (2 Methods: In this study, an oleaginous yeast, Rhodotorula glutinis, was used for direct transesterification without lipid pre-extraction to produce biodiesel, using sulfuric acid or sodium hydroxide as a catalyst. Such processes decreased the amount of energy and organic solvents required simultaneously; (3 Results: When 1 g of dry R. glutinis biomass was subject to direct transesterification in 20 mL of methanol catalyzed by 0.6 M H2SO4 at 70 °C for 20 h, the fatty acid methyl ester (FAME yield reached 111%. Using the same amount of biomass and methanol loading but catalyzed by 1 g/L NaOH at 70 °C for 10 h, the FAME yield reached 102%. The acid-catalyzed process showed a superior moisture tolerance; when the biomass contained 70% moisture, the FAME yield was 43% as opposed to 34% of the base-catalyzed counterpart; (4 Conclusions: Compared to conventional transesterification, which requires lipid pre-extraction, direct transesterification not only simplifies the process and shortens the reaction time, but also improves the FAME yield.

  10. Improving North American forest biomass estimates from literature synthesis and meta-analysis of existing biomass equations

    Science.gov (United States)

    David C. Chojnacky; Jennifer C. Jenkins; Amanda K. Holland

    2009-01-01

    Thousands of published equations purport to estimate biomass of individual trees. These equations are often based on very small samples, however, and can provide widely different estimates for trees of the same species. We addressed this issue in a previous study by devising 10 new equations that estimated total aboveground biomass for all species in North America (...

  11. Microbial plankton communities in the coastal southeastern Black Sea: biomass, composition and trophic interactions

    Directory of Open Access Journals (Sweden)

    Ulgen Aytan

    2018-04-01

    Full Text Available Summary: We investigated biomass and composition of the pico-, nano- and microplankton communities in a coastal station of the southeastern Black Sea during 2011. We also examined trophic interactions within these communities from size-fractionated dilution experiments in February, June and December. Autotrophic and heterotrophic biomasses showed similar seasonal trends, with a peak in June, but heterotrophs dominated throughout the year. Autotrophic biomass was mainly comprised by nanoflagellates and diatoms in the first half of the year, and by dinoflagellates and Synechococcus spp. in the second half. Heterotrophic biomass was mostly dominated by heterotrophic bacteria, followed by nanoflagellates and microzooplankton. Dilution experiments suggest that nano- and microzooplankton were significant consumers of autotrophs and heterotrophic bacteria. More than 100% of bacterial production was consumed by grazers in all experiments, while 46%, 21% and 30% of daily primary production were consumed in February, June and December, respectively. In February, autotrophs were the main carbon source, but in December, it was heterotrophic bacteria. An intermediate situation was observed in June, with similar carbon flows from autotrophs and heterotrophic bacteria. Size-fraction dilution experiments suggested that heterotrophic nanoflagellates are an important link between the high heterotrophic bacterial biomass and microzooplankton. In summary, these results indicate that nano- and microzooplankton were responsible for comprising a significant fraction of total microbial plankton biomass, standing stocks, growth and grazing processes. This suggests that in 2011, the microbial food web was an important compartment of the planktonic food web in the coastal southeastern Black Sea. Keywords: Phytoplankton, Microzooplankton, Carbon biomass, Microbial food web, Grazing, Black Sea

  12. Soil Microbial Biomass, Basal Respiration and Enzyme Activity of Main Forest Types in the Qinling Mountains

    Science.gov (United States)

    Cheng, Fei; Peng, Xiaobang; Zhao, Peng; Yuan, Jie; Zhong, Chonggao; Cheng, Yalong; Cui, Cui; Zhang, Shuoxin

    2013-01-01

    Different forest types exert essential impacts on soil physical-chemical characteristics by dominant tree species producing diverse litters and root exudates, thereby further regulating size and activity of soil microbial communities. However, the study accuracy is usually restricted by differences in climate, soil type and forest age. Our objective is to precisely quantify soil microbial biomass, basal respiration and enzyme activity of five natural secondary forest (NSF) types with the same stand age and soil type in a small climate region and to evaluate relationship between soil microbial and physical-chemical characters. We determined soil physical-chemical indices and used the chloroform fumigation-extraction method, alkali absorption method and titration or colorimetry to obtain the microbial data. Our results showed that soil physical-chemical characters remarkably differed among the NSFs. Microbial biomass carbon (Cmic) was the highest in wilson spruce soils, while microbial biomass nitrogen (Nmic) was the highest in sharptooth oak soils. Moreover, the highest basal respiration was found in the spruce soils, but mixed, Chinese pine and spruce stands exhibited a higher soil qCO2. The spruce soils had the highest Cmic/Nmic ratio, the greatest Nmic/TN and Cmic/Corg ratios were found in the oak soils. Additionally, the spruce soils had the maximum invertase activity and the minimum urease and catalase activities, but the maximum urease and catalase activities were found in the mixed stand. The Pearson correlation and principle component analyses revealed that the soils of spruce and oak stands obviously discriminated from other NSFs, whereas the others were similar. This suggested that the forest types affected soil microbial properties significantly due to differences in soil physical-chemical features. PMID:23840671

  13. Microbial biomass dynamics dominate N cycle responses to warming in a sub-arctic peatland

    Science.gov (United States)

    Weedon, J. T.; Aerts, R.; Kowalchuk, G. K.; van Bodegom, P. M.

    2012-04-01

    The balance of primary production and decomposition in sub-arctic peatlands may shift with climate change. Nitrogen availability will modulate this shift, but little is known about the drivers of soil nitrogen dynamics in these environments, and how they are influenced by rising soil temperatures. We used a long-term open top chamber warming experiment in Abisko, Sweden, to test for the interactive effects of spring warming, summer warming and winter snow addition on soil organic and inorganic nitrogen fluxes, potential activities of carbon and nitrogen cycle enzymes, and the structure of the soil-borne microbial communities. Summer warming increased the flux of soil organic nitrogen over the growing season, while simultaneously causing a seasonal decrease in microbial biomass, suggesting that N flux is driven by large late-season dieback of microbes. This change in N cycle dynamics was not reflected in any of the measured potential enzyme activities. Moreover, the soil microbial community structure was stable across treatments, suggesting non-specific microbial dieback. To further test whether the observed patterns were driven by direct temperature effects or indirect effects (via microbial biomass dynamics), we conducted follow-up controlled experiments in soil mesocosms. Experimental additions of dead microbial cells had stronger effects on N pool sizes and enzyme activities than either plant litter addition or a 5 °C alteration in incubation temperatures. Peat respiration was positively affected by both substrate addition and higher incubation temperatures, but the temperature-only effect was not sufficient to account for the increases in respiration observed in previous field experiments. We conclude that warming effects on peatland N cycling (and to some extent C cycling) are dominated by indirect effects, acting through alterations to the seasonal flux of microbe-derived organic matter. We propose that climate change models of soil carbon and nitrogen

  14. Influence of diligent disintegration on anaerobic biomass and performance of microbial fuel cell.

    Science.gov (United States)

    Divyalakshmi, Palanisamy; Murugan, Devaraj; Rai, Chockalingam Lajapathi

    2017-12-01

    To enhance the performance of microbial fuel cells (MFC) by increasing the surface area of cathode and diligent mechanical disintegration of anaerobic biomass. Tannery effluent and anaerobic biomass were used. The increase in surface area of the cathode resulted in 78% COD removal, with the potential, current density, power density and coulombic efficiency of 675 mV, 147 mA m -2 , 33 mW m -2 and 3.5%, respectively. The work coupled with increased surface area of the cathode with diligent mechanical disintegration of the biomass, led to a further increase in COD removal of 82% with the potential, current density, power density and coulombic efficiency of 748 mV, 229 mA m -2 , 78 mW m -2 and 6% respectively. Mechanical disintegration of the biomass along with increased surface area of cathode enhances power generation in vertical MFC reactors using tannery effluent as fuel.

  15. Optimizing Sampling Efficiency for Biomass Estimation Across NEON Domains

    Science.gov (United States)

    Abercrombie, H. H.; Meier, C. L.; Spencer, J. J.

    2013-12-01

    Over the course of 30 years, the National Ecological Observatory Network (NEON) will measure plant biomass and productivity across the U.S. to enable an understanding of terrestrial carbon cycle responses to ecosystem change drivers. Over the next several years, prior to operational sampling at a site, NEON will complete construction and characterization phases during which a limited amount of sampling will be done at each site to inform sampling designs, and guide standardization of data collection across all sites. Sampling biomass in 60+ sites distributed among 20 different eco-climatic domains poses major logistical and budgetary challenges. Traditional biomass sampling methods such as clip harvesting and direct measurements of Leaf Area Index (LAI) involve collecting and processing plant samples, and are time and labor intensive. Possible alternatives include using indirect sampling methods for estimating LAI such as digital hemispherical photography (DHP) or using a LI-COR 2200 Plant Canopy Analyzer. These LAI estimations can then be used as a proxy for biomass. The biomass estimates calculated can then inform the clip harvest sampling design during NEON operations, optimizing both sample size and number so that standardized uncertainty limits can be achieved with a minimum amount of sampling effort. In 2011, LAI and clip harvest data were collected from co-located sampling points at the Central Plains Experimental Range located in northern Colorado, a short grass steppe ecosystem that is the NEON Domain 10 core site. LAI was measured with a LI-COR 2200 Plant Canopy Analyzer. The layout of the sampling design included four, 300 meter transects, with clip harvests plots spaced every 50m, and LAI sub-transects spaced every 10m. LAI was measured at four points along 6m sub-transects running perpendicular to the 300m transect. Clip harvest plots were co-located 4m from corresponding LAI transects, and had dimensions of 0.1m by 2m. We conducted regression analyses

  16. Annual Removal of Aboveground Plant Biomass Alters Soil Microbial Responses to Warming

    Directory of Open Access Journals (Sweden)

    Kai Xue

    2016-09-01

    Full Text Available Clipping (i.e., harvesting aboveground plant biomass is common in agriculture and for bioenergy production. However, microbial responses to clipping in the context of climate warming are poorly understood. We investigated the interactive effects of grassland warming and clipping on soil properties and plant and microbial communities, in particular, on microbial functional genes. Clipping alone did not change the plant biomass production, but warming and clipping combined increased the C4 peak biomass by 47% and belowground net primary production by 110%. Clipping alone and in combination with warming decreased the soil carbon input from litter by 81% and 75%, respectively. With less carbon input, the abundances of genes involved in degrading relatively recalcitrant carbon increased by 38% to 137% in response to either clipping or the combined treatment, which could weaken long-term soil carbon stability and trigger positive feedback with respect to warming. Clipping alone also increased the abundance of genes for nitrogen fixation, mineralization, and denitrification by 32% to 39%. Such potentially stimulated nitrogen fixation could help compensate for the 20% decline in soil ammonium levels caused by clipping alone and could contribute to unchanged plant biomass levels. Moreover, clipping tended to interact antagonistically with warming, especially with respect to effects on nitrogen cycling genes, demonstrating that single-factor studies cannot predict multifactorial changes. These results revealed that clipping alone or in combination with warming altered soil and plant properties as well as the abundance and structure of soil microbial functional genes. Aboveground biomass removal for biofuel production needs to be reconsidered, as the long-term soil carbon stability may be weakened.

  17. Taxonomic and Functional Responses of Soil Microbial Communities to Annual Removal of Aboveground Plant Biomass

    Science.gov (United States)

    Guo, Xue; Zhou, Xishu; Hale, Lauren; Yuan, Mengting; Feng, Jiajie; Ning, Daliang; Shi, Zhou; Qin, Yujia; Liu, Feifei; Wu, Liyou; He, Zhili; Van Nostrand, Joy D.; Liu, Xueduan; Luo, Yiqi; Tiedje, James M.; Zhou, Jizhong

    2018-01-01

    Clipping, removal of aboveground plant biomass, is an important issue in grassland ecology. However, few studies have focused on the effect of clipping on belowground microbial communities. Using integrated metagenomic technologies, we examined the taxonomic and functional responses of soil microbial communities to annual clipping (2010–2014) in a grassland ecosystem of the Great Plains of North America. Our results indicated that clipping significantly (P microbial respiration rates. Annual temporal variation within the microbial communities was much greater than the significant changes introduced by clipping, but cumulative effects of clipping were still observed in the long-term scale. The abundances of some bacterial and fungal lineages including Actinobacteria and Bacteroidetes were significantly (P microbial communities were significantly correlated with soil respiration and plant productivity. Intriguingly, clipping effects on microbial function may be highly regulated by precipitation at the interannual scale. Altogether, our results illustrated the potential of soil microbial communities for increased soil organic matter decomposition under clipping land-use practices. PMID:29904372

  18. Estimating externalities of biomass fuel cycles, Report 7

    Energy Technology Data Exchange (ETDEWEB)

    Barnthouse, L.W.; Cada, G.F.; Cheng, M.-D.; Easterly, C.E.; Kroodsma, R.L.; Lee, R.; Shriner, D.S.; Tolbert, V.R.; Turner, R.S.

    1998-01-01

    This report documents the analysis of the biomass fuel cycle, in which biomass is combusted to produce electricity. The major objectives of this study were: (1) to implement the methodological concepts which were developed in the Background Document (ORNL/RFF 1992) as a means of estimating the external costs and benefits of fuel cycles, and by so doing, to demonstrate their application to the biomass fuel cycle; (2) to develop, given the time and resources, a range of estimates of marginal (i.e., the additional or incremental) damages and benefits associated with selected impact-pathways from a new wood-fired power plant, using a representative benchmark technology, at two reference sites in the US; and (3) to assess the state of the information available to support energy decision making and the estimation of externalities, and by so doing, to assist in identifying gaps in knowledge and in setting future research agendas. The demonstration of methods, modeling procedures, and use of scientific information was the most important objective of this study. It provides an illustrative example for those who will, in the future, undertake studies of actual energy options and sites. As in most studies, a more comprehensive analysis could have been completed had budget constraints not been as severe. Particularly affected were the air and water transport modeling, estimation of ecological impacts, and economic valuation. However, the most important objective of the study was to demonstrate methods, as a detailed example for future studies. Thus, having severe budget constraints was appropriate from the standpoint that these studies could also face similar constraints. Consequently, an important result of this study is an indication of what can be done in such studies, rather than the specific numerical estimates themselves.

  19. A survey of Opportunities for Microbial Conversion of Biomass to Hydrocarbon Compatible Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, Iva; Jones, Susanne B.; Santosa, Daniel M.; Dai, Ziyu; Ramasamy, Karthikeyan K.; Zhu, Yunhua

    2010-09-01

    Biomass is uniquely able to supply renewable and sustainable liquid transportation fuels. In the near term, the Biomass program has a 2012 goal of cost competitive cellulosic ethanol. However, beyond 2012, there will be an increasing need to provide liquid transportation fuels that are more compatible with the existing infrastructure and can supply fuel into all transportation sectors, including aviation and heavy road transport. Microbial organisms are capable of producing a wide variety of fuel and fuel precursors such as higher alcohols, ethers, esters, fatty acids, alkenes and alkanes. This report surveys liquid fuels and fuel precurors that can be produced from microbial processes, but are not yet ready for commercialization using cellulosic feedstocks. Organisms, current research and commercial activities, and economics are addressed. Significant improvements to yields and process intensification are needed to make these routes economic. Specifically, high productivity, titer and efficient conversion are the key factors for success.

  20. Dynamic relationships between microbial biomass, respiration, inorganic nutrients and enzyme activities: informing enzyme based decomposition models

    Directory of Open Access Journals (Sweden)

    Daryl L Moorhead

    2013-08-01

    Full Text Available We re-examined data from a recent litter decay study to determine if additional insights could be gained to inform decomposition modeling. Rinkes et al. (2013 conducted 14-day laboratory incubations of sugar maple (Acer saccharum or white oak (Quercus alba leaves, mixed with sand (0.4% organic C content or loam (4.1% organic C. They measured microbial biomass C, carbon dioxide efflux, soil ammonium, nitrate, and phosphate concentrations, and β-glucosidase (BG, β-N-acetyl-glucosaminidase (NAG, and acid phosphatase (AP activities on days 1, 3, and 14. Analyses of relationships among variables yielded different insights than original analyses of individual variables. For example, although respiration rates per g soil were higher for loam than sand, rates per g soil C were actually higher for sand than loam, and rates per g microbial C showed little difference between treatments. Microbial biomass C peaked on day 3 when biomass-specific activities of enzymes were lowest, suggesting uptake of litter C without extracellular hydrolysis. This result refuted a common model assumption that all enzyme production is constitutive and thus proportional to biomass, and/or indicated that part of litter decay is independent of enzyme activity. The length and angle of vectors defined by ratios of enzyme activities (BG/NAG versus BG/AP represent relative microbial investments in C (length, and N and P (angle acquiring enzymes. Shorter lengths on day 3 suggested low C limitation, whereas greater lengths on day 14 suggested an increase in C limitation with decay. The soils and litter in this study generally had stronger P limitation (angles > 45˚. Reductions in vector angles to < 45˚ for sand by day 14 suggested a shift to N limitation. These relational variables inform enzyme-based models, and are usually much less ambiguous when obtained from a single study in which measurements were made on the same samples than when extrapolated from separate studies.

  1. Microbial growth yield estimates from thermodynamics and its importance for degradation of pesticides and formation of biogenic non-extractable residues

    DEFF Research Database (Denmark)

    Brock, Andreas Libonati; Kästner, M.; Trapp, Stefan

    2017-01-01

    NER. Formation of microbial mass can be estimated from the microbial growth yield, but experimental data is rare. Instead, we suggest using prediction methods for the theoretical yield based on thermodynamics. Recently, we presented the Microbial Turnover to Biomass (MTB) method that needs a minimum...... and using the released CO2 as a measure for microbial activity, we predicted a range for the formation of biogenic NER. For the majority of the pesticides, a considerable fraction of the NER was estimated to be biogenic. This novel approach provides a theoretical foundation applicable to the evaluation...

  2. Long-term effects of aided phytostabilisation of trace elements on microbial biomass and activity, enzyme activities, and composition of microbial community in the Jales contaminated mine spoils

    Energy Technology Data Exchange (ETDEWEB)

    Renella, Giancarlo [Department of Soil Science and Plant Nutrition, University of Florence, Piazzale delle Cascine 28, I-50144 Florence (Italy)], E-mail: giancarlo.renella@unifi.it; Landi, Loretta; Ascher, Judith; Ceccherini, Maria Teresa; Pietramellara, Giacomo; Mench, Michel; Nannipieri, Paolo [Department of Soil Science and Plant Nutrition, University of Florence, Piazzale delle Cascine 28, I-50144 Florence (Italy)

    2008-04-15

    We studied the effectiveness of remediation on microbial endpoints, namely microbial biomass and activity, microbial and plant species richness, of an As-contaminated mine spoil, amended with compost (C) alone and in combination with beringite (B) or zerovalent iron grit (Z), to increase organic matter content and reduce trace elements mobility, and to allow Holcus lanatus and Pinus pinaster growth. Untreated spoil showed the lowest microbial biomass and activity and hydrolase activities, and H. lanatus as sole plant species, whereas the presented aided phytostabilisation option, especially CBZ treatment, significantly increased microbial biomass and activity and allowed colonisation by several plant species, comparable to those of an uncontaminated sandy soil. Microbial species richness was only increased in spoils amended with C alone. No clear correlation occurred between trace element mobility and microbial parameters and plant species richness. Our results indicate that the choice of indicators of soil remediation practices is a bottleneck. - Organo-mineral amendment and revegetation of a gold mine spoil increased microbial activity but did not increase microbial species richness.

  3. Long-term effects of aided phytostabilisation of trace elements on microbial biomass and activity, enzyme activities, and composition of microbial community in the Jales contaminated mine spoils

    International Nuclear Information System (INIS)

    Renella, Giancarlo; Landi, Loretta; Ascher, Judith; Ceccherini, Maria Teresa; Pietramellara, Giacomo; Mench, Michel; Nannipieri, Paolo

    2008-01-01

    We studied the effectiveness of remediation on microbial endpoints, namely microbial biomass and activity, microbial and plant species richness, of an As-contaminated mine spoil, amended with compost (C) alone and in combination with beringite (B) or zerovalent iron grit (Z), to increase organic matter content and reduce trace elements mobility, and to allow Holcus lanatus and Pinus pinaster growth. Untreated spoil showed the lowest microbial biomass and activity and hydrolase activities, and H. lanatus as sole plant species, whereas the presented aided phytostabilisation option, especially CBZ treatment, significantly increased microbial biomass and activity and allowed colonisation by several plant species, comparable to those of an uncontaminated sandy soil. Microbial species richness was only increased in spoils amended with C alone. No clear correlation occurred between trace element mobility and microbial parameters and plant species richness. Our results indicate that the choice of indicators of soil remediation practices is a bottleneck. - Organo-mineral amendment and revegetation of a gold mine spoil increased microbial activity but did not increase microbial species richness

  4. Effects of elevated nitrogen deposition on soil microbial biomass carbon in major subtropical forests of southern China

    Institute of Scientific and Technical Information of China (English)

    Hui WANG; Jiangming MO; Xiankai LU; Jinghua XUE; Jiong LI; Yunting FANG

    2009-01-01

    The effects of elevated nitrogen deposition on soil microbial biomass carbon (C) and extractable dissolved organic carbon (DOC) in three types of forest of southern China were studied in November, 2004 and June, 2006. Plots were established in a pine forest (PF), a mixed pine and broad-leaved forest (MF) and monsoon evergreen broad-leaved forest (MEBF) in the Dinghushan Nature Reserve. Nitrogen treatments included a control (no N addition), low N (50 kg N/(hm2.a)), medium N (100 kg N/ (hm2. a)) and high N (150 kg N/(hm2. a)). Microbial biomass C and extractable DOC were determined using a chloro-form fumigation-extraction method. Results indicate that microbial biomass C and extractable DOC were higher in June, 2006 than in November, 2004 and higher in the MEBF than in the PF or the MF. The response of soil microbial biomass C and extractable DOC to nitrogen deposition varied depending on the forest type and the level of nitrogen treatment. In the PF or MF forests, no significantly different effects of nitrogen addition were found on soil microbial biomass C and extractable DOC. In the MEBF, however, the soil microbial biomass C generally decreased with increased nitrogen levels and high nitrogen addition significantly reduced soil microbial biomass C. The response of soil extractable DOC to added nitrogen in the MEBF shows the opposite trend to soil microbial biomass C. These results suggest that nitrogen deposition may increase the accumulation of soil organic carbon in the MEBF in the study region.

  5. Microbial biomass and activity in litter during the initial development of pure and mixed plantations of Eucalyptus grandis and Acacia mangium

    Directory of Open Access Journals (Sweden)

    Daniel Bini

    2013-02-01

    Full Text Available Studies on microbial activity and biomass in forestry plantations often overlook the role of litter, typically focusing instead on soil nutrient contents to explain plant and microorganism development. However, since the litter is a significant source of recycled nutrients that affect nutrient dynamics in the soil, litter composition may be more strongly correlated with forest growth and development than soil nutrient contents. This study aimed to test this hypothesis by examining correlations between soil C, N, and P; litter C, N, P, lignin content, and polyphenol content; and microbial biomass and activity in pure and mixed second-rotation plantations of Eucalyptus grandis and Acacia mangium before and after senescent leaf drop. The numbers of cultivable fungi and bacteria were also estimated. All properties were correlated with litter C, N, P, lignin and polyphenols, and with soil C and N. We found higher microbial activity (CO2 evolution in litter than in soil. In the E. grandis monoculture before senescent leaf drop, microbial biomass C was 46 % higher in litter than in soil. After leaf drop, this difference decreased to 16 %. In A. mangium plantations, however, microbial biomass C was lower in litter than in soil both before and after leaf drop. Microbial biomass N of litter was approximately 94 % greater than that of the soil in summer and winter in all plantations. The number of cultivable fungi and bacteria increased after leaf drop, especially so in the litter. Fungi were also more abundant in the E. grandis litter. In general, the A. mangium monoculture was associated with higher levels of litter lignin and N, especially after leaf drop. In contrast, the polyphenol and C levels in E. grandis monoculture litter were higher after leaf drop. These properties were negatively correlated with total soil C and N. Litter in the mixed stands had lower C:N and C:P ratios and higher N, P, and C levels in the microbial biomass. This suggests more

  6. Continuous exposure of pesticides in an aquifer changes microbial biomass, diversity and degradation potential

    DEFF Research Database (Denmark)

    de Lipthay, J. R.; Johnsen, K.; Aamand, J.

    2000-01-01

    We studied in situ effects of pesticide exposure on microbial degradation potential and community structure of aquifer sediments. Sediment samples pre-exposed to pesticides were significantly different to non-exposed control samples. Pre-exposed sediment showed an increased degradation potential ...... towards phenoxyalcanoic acid herbicides as well as impact on microbial diversity was observed. Furthermore, bacterial biomass was changed, e.g. increased numbers of phenoxyalcanoic acid degraders in pesticide exposed sediment.......We studied in situ effects of pesticide exposure on microbial degradation potential and community structure of aquifer sediments. Sediment samples pre-exposed to pesticides were significantly different to non-exposed control samples. Pre-exposed sediment showed an increased degradation potential...

  7. Analysis of Low-Biomass Microbial Communities in the Deep Biosphere.

    Science.gov (United States)

    Morono, Y; Inagaki, F

    2016-01-01

    Over the past few decades, the subseafloor biosphere has been explored by scientific ocean drilling to depths of about 2.5km below the seafloor. Although organic-rich anaerobic sedimentary habitats in the ocean margins harbor large numbers of microbial cells, microbial populations in ultraoligotrophic aerobic sedimentary habitats in the open ocean gyres are several orders of magnitude less abundant. Despite advances in cultivation-independent molecular ecological techniques, exploring the low-biomass environment remains technologically challenging, especially in the deep subseafloor biosphere. Reviewing the historical background of deep-biosphere analytical methods, the importance of obtaining clean samples and tracing contamination, as well as methods for detecting microbial life, technological aspects of molecular microbiology, and detecting subseafloor metabolic activity will be discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Earthworms facilitate the stabilization of pelletized dewatered sludge through shaping microbial biomass and activity and community.

    Science.gov (United States)

    Fu, Xiaoyong; Cui, Guangyu; Huang, Kui; Chen, Xuemin; Li, Fusheng; Zhang, Xiaoyu; Li, Fei

    2016-03-01

    In this study, the effect of earthworms on microbial features during vermicomposting of pelletized dewatered sludge (PDS) was investigated through comparing two degradation systems with and without earthworm E isenia fetida involvement. After 60 days of experimentation, a relatively stable product with low organic matter and high nitrate and phosphorous was harvested when the earthworms were involved. During the process, earthworms could enhance microbial activity and biomass at the initial stage and thus accelerating the rapid decomposition of PDS. The end products of vermicomposting allowed the lower values of bacterial and eukaryotic densities comparison with those of no earthworm addition. In addition, the presence of earthworms modified the bacterial and fungal diversity, making the disappearances of some pathogens and specific decomposing bacteria of recalcitrant substrates in the vermicomposting process. This study evidences that earthworms can facilitate the stabilization of PDS through modifying microbial activity and number and community during vermicomposting.

  9. Effects of lead and cadmium nitrate on biomass and substrate utilization pattern of soil microbial communities.

    Science.gov (United States)

    Muhammad, Akmal; Xu, Jianming; Li, Zhaojun; Wang, Haizhen; Yao, Huaiying

    2005-07-01

    A study was conducted to evaluate the effects of different concentrations of lead (Pb) and cadmium (Cd) applied as their nitrates on soil microbial biomass carbon (C(mic)) and nitrogen (N(mic)), and substrate utilization pattern of soil microbial communities. The C(mic) and N(mic) contents were determined at 0, 14, 28, 42 and 56 days after heavy metal application (DAA). The results showed a significant decline in the C(mic) for all Pb and Cd amended soils from the start to 28 DAA. From 28 to 56 DAA, C(mic) contents changed non-significantly for all other treatments except for 600 mgkg(-1) Pb and 100 mgkg(-1) Cd in which it declined significantly from 42 to 56 DAA. The N(mic) contents also decreased significantly from start to 28 DAA for all other Pb and Cd treatments except for 200 mgkg(-1) Pb which did not show significant difference from the control. Control and 200 mgkg(-1) Pb had significantly lower soil microbial biomass C:N ratio as compared with other Pb treatments from 14 to 42 DAA, however at 56 DAA, only 1000 mgkg(-1) Pb showed significantly higher C:N ratio compared with other treatments. No significant difference in C:N ratio for all Cd treated soils was seen from start to 28 DAA, however from 42 to 56 DAA, 100 mgkg(-1) Pb showed significantly higher C:N ratio compared with other treatments. On 56 DAA, substrate utilization pattern of soil microbial communities was determined by inoculating Biolog ECO plates. The results indicated that Pb and Cd addition inhibited the functional activity of soil microbial communities as indicated by the intensity of average well color development (AWCD) during 168 h of incubation. Multivariate analysis of sole carbon source utilization pattern demonstrated that higher levels of heavy metal application had significantly affected soil microbial community structure.

  10. Estimation of alewife biomass in Lake Michigan, 1967-1978

    Science.gov (United States)

    Hatch, Richard W.; Haack, Paul M.; Brown, Edward H.

    1981-01-01

    The buildup of salmonid populations in Lake Michigan through annual stockings of hatchery-reared fish may become limited by the quantity of forage fish, mainly alewives Alosa pseudoharengus, available for food. As a part of a continuing examination of salmonid predator-prey relations in Lake Michigan, we traced changes in alewife biomass estimated from bottom-trawl surveys conducted in late October and early November 1967–1978. Weight of adult alewives trawled per 0.5 hectare of bottom (10-minute drag) at 16 depths along eight transects between 1973 and 1977 formed a skewed distribution: 72 of 464 drags caught no alewives; 89 drags caught less than 1 kg; and 2 drags caught more than 100 kg (maximum 159 kg). Analysis of variance in normalized catch per tow indicated highly significant differences between the main effects of years and depths, and highly significant differences in the interactions of years and transects, years and depths, and transects and depths. Five geographic and depth strata, formed by combining parts of transects wherein mean catch rate did not differ significantly, were the basis for calculating annual estimates of adult alewife biomass (with 90% confidence intervals). Estimated biomass of alewives (±90% confidence limits) in Lake Michigan proper (Green Bay and Grand Traverse Bay excluded) rose gradually from 46,000 (±9,000) t in 1967 to 114,000 (±17,000) t in 1973, declined to 45,000 (±8,000) t in 1977, and rose to 77,000 (±19,000) t in 1978.

  11. Estimating terrestrial aboveground biomass estimation using lidar remote sensing: a meta-analysis

    Science.gov (United States)

    Zolkos, S. G.; Goetz, S. J.; Dubayah, R.

    2012-12-01

    Estimating biomass of terrestrial vegetation is a rapidly expanding research area, but also a subject of tremendous interest for reducing carbon emissions associated with deforestation and forest degradation (REDD). The accuracy of biomass estimates is important in the context carbon markets emerging under REDD, since areas with more accurate estimates command higher prices, but also for characterizing uncertainty in estimates of carbon cycling and the global carbon budget. There is particular interest in mapping biomass so that carbon stocks and stock changes can be monitored consistently across a range of scales - from relatively small projects (tens of hectares) to national or continental scales - but also so that other benefits of forest conservation can be factored into decision making (e.g. biodiversity and habitat corridors). We conducted an analysis of reported biomass accuracy estimates from more than 60 refereed articles using different remote sensing platforms (aircraft and satellite) and sensor types (optical, radar, lidar), with a particular focus on lidar since those papers reported the greatest efficacy (lowest errors) when used in the a synergistic manner with other coincident multi-sensor measurements. We show systematic differences in accuracy between different types of lidar systems flown on different platforms but, perhaps more importantly, differences between forest types (biomes) and plot sizes used for field calibration and assessment. We discuss these findings in relation to monitoring, reporting and verification under REDD, and also in the context of more systematic assessment of factors that influence accuracy and error estimation.

  12. Developing a generalized allometric equation for aboveground biomass estimation

    Science.gov (United States)

    Xu, Q.; Balamuta, J. J.; Greenberg, J. A.; Li, B.; Man, A.; Xu, Z.

    2015-12-01

    A key potential uncertainty in estimating carbon stocks across multiple scales stems from the use of empirically calibrated allometric equations, which estimate aboveground biomass (AGB) from plant characteristics such as diameter at breast height (DBH) and/or height (H). The equations themselves contain significant and, at times, poorly characterized errors. Species-specific equations may be missing. Plant responses to their local biophysical environment may lead to spatially varying allometric relationships. The structural predictor may be difficult or impossible to measure accurately, particularly when derived from remote sensing data. All of these issues may lead to significant and spatially varying uncertainties in the estimation of AGB that are unexplored in the literature. We sought to quantify the errors in predicting AGB at the tree and plot level for vegetation plots in California. To accomplish this, we derived a generalized allometric equation (GAE) which we used to model the AGB on a full set of tree information such as DBH, H, taxonomy, and biophysical environment. The GAE was derived using published allometric equations in the GlobAllomeTree database. The equations were sparse in details about the error since authors provide the coefficient of determination (R2) and the sample size. A more realistic simulation of tree AGB should also contain the noise that was not captured by the allometric equation. We derived an empirically corrected variance estimate for the amount of noise to represent the errors in the real biomass. Also, we accounted for the hierarchical relationship between different species by treating each taxonomic level as a covariate nested within a higher taxonomic level (e.g. species contribution of each different covariate in estimating the AGB of trees. Lastly, we applied the GAE to an existing vegetation plot database - Forest Inventory and Analysis database - to derive per-tree and per-plot AGB estimations, their errors, and how

  13. Effect of buctril super (Bromoxynil herbicide on soil microbial biomass and bacterial population

    Directory of Open Access Journals (Sweden)

    Zafar Abbas

    2014-02-01

    Full Text Available The present study aimed to evaluate the effect of bromoxynil herbicide on soil microorganisms, with the hypothesis that this herbicide caused suppression in microbial activity and biomass by exerting toxic effect on them. Nine sites of Punjab province (Pakistan those had been exposed to bromoxynil herbicide for about last ten years designated as soil 'A' were surveyed in 2011 and samples were collected and analyzed for Microbial Biomass Carbon (MBC, Biomass Nitrogen (MBN, Biomass Phosphorus (MBP and bacterial population. Simultaneously, soil samples from the same areas those were not exposed to herbicide designated as soil 'B' were taken. At all the sites MBC, MBN and MBP ranged from 131 to 457, 1.22 to 13.1 and 0.59 to 3.70 µg g-1 in the contaminated soils (Soil A, which was 187 to 573, 1.70 to 14.4 and 0.72 to 4.12 µg g-1 in the soils without contamination (soil B. Bacterial population ranged from 0.67 to 1.84x10(8 and 0.87 to 2.37x10(8 cfu g-1 soil in the soils A and B, respectively. Bromoxynil residues ranged from 0.09 to 0.24 mg kg-1 at all the sites in soil A. But no residues were detected in the soil B. Due to lethal effect of bromoxynil residues on the above parameters, considerable decline in these parameters was observed in the contaminated soils. Results depicted that the herbicide had left toxic effects on soil microbial parameters, thus confirmed that continuous use of this herbicide affected the quality of soil and sustainable crop production.

  14. Inventory-based estimates of forest biomass carbon stocks in China: A comparison of three methods

    Science.gov (United States)

    Zhaodi Guo; Jingyun Fang; Yude Pan; Richard. Birdsey

    2010-01-01

    Several studies have reported different estimates for forest biomass carbon (C) stocks in China. The discrepancy among these estimates may be largely attributed to the methods used. In this study, we used three methods [mean biomass density method (MBM), mean ratio method (MRM), and continuous biomass expansion factor (BEF) method (abbreviated as CBM)] applied to...

  15. ALLOMETRIC EQUATIONS FOR ESTIMATING ABOVEGROUND BIOMASS IN PAPUA TROPICAL FOREST

    Directory of Open Access Journals (Sweden)

    Sandhi Imam Maulana

    2014-10-01

    Full Text Available Allometric equations can be used to estimate biomass and carbon stock of  the forest. However, so far the allometric equations for commercial species in Papua tropical forests have not been appropriately developed. In this research, allometric equations are presented based on the genera of  commercial species. Few equations have been developed for the commercial species of  Intsia, Pometia, Palaquium and Vatica genera and an equation of  a mix of  these genera. The number of  trees sampled in this research was 49, with diameters (1.30 m above-ground or above buttresses ranging from 5 to 40 cm. Destructive sampling was used to collect the samples where Diameter at Breast Height (DBH and Wood Density (WD were used as predictors for dry weight of  Total Above-Ground Biomass (TAGB. Model comparison and selection were based on the values of  F-statistics, R-sq, R-sq (adj, and average deviation. Based on these statistical indicators, the most suitable model for Intsia, Pometia, Palaquium and Vatica genera respectively are Log(TAGB = -0.76 + 2.51Log(DBH, Log(TAGB = -0.84 + 2.57Log(DBH, Log(TAGB = -1.52 + 2.96Log(DBH, and Log(TAGB = -0.09 + 2.08Log(DBH. Additional explanatory variables such as Commercial Bole Height (CBH do not really increase the indicators’ goodness of  fit for the equation. An alternative model to incorporate wood density should  be considered for estimating the above-ground biomass for mixed genera. Comparing the presented mixed-genera equation; Log(TAGB = 0.205 + 2.08Log(DBH + 1.75Log(WD, R-sq: 97.0%, R-sq (adj: 96.9%, F statistics 750.67, average deviation: 3.5%; to previously published datashows that this local species specific equation differs substantially from previously published equations and this site-specific equation is  considered to give a better estimation of  biomass.

  16. Testing the sensitivity of terrestrial carbon models using remotely sensed biomass estimates

    Science.gov (United States)

    Hashimoto, H.; Saatchi, S. S.; Meyer, V.; Milesi, C.; Wang, W.; Ganguly, S.; Zhang, G.; Nemani, R. R.

    2010-12-01

    There is a large uncertainty in carbon allocation and biomass accumulation in forest ecosystems. With the recent availability of remotely sensed biomass estimates, we now can test some of the hypotheses commonly implemented in various ecosystem models. We used biomass estimates derived by integrating MODIS, GLAS and PALSAR data to verify above-ground biomass estimates simulated by a number of ecosystem models (CASA, BIOME-BGC, BEAMS, LPJ). This study extends the hierarchical framework (Wang et al., 2010) for diagnosing ecosystem models by incorporating independent estimates of biomass for testing and calibrating respiration, carbon allocation, turn-over algorithms or parameters.

  17. The effect of D123 wheat as a companion crop on soil enzyme activities, microbial biomass and microbial communities in the rhizosphere of watermelon.

    Science.gov (United States)

    Xu, Weihui; Wang, Zhigang; Wu, Fengzhi

    2015-01-01

    The growth of watermelon is often threatened by Fusarium oxysporum f. sp. niveum (Fon) in successively monocultured soil, which results in economic loss. The objective of this study was to investigate the effect of D123 wheat as a companion crop on soil enzyme activities, microbial biomass and microbial communities in the rhizosphere of watermelon and to explore the relationship between the effect and the incidence of wilt caused by Fon. The results showed that the activities of soil polyphenol oxidase, urease and invertase were increased, the microbial biomass nitrogen (MBN) and microbial biomass phosphorus (MBP) were significantly increased, and the ratio of MBC/MBN was decreased (P Fusarium wilt was also decreased in the watermelon/wheat companion system. In conclusion, this study indicated that D123 wheat as a companion crop increased soil enzyme activities and microbial biomass, decreased the Fon population, and changed the relative abundance of microbial communities in the rhizosphere of watermelon, which may be related to the reduction of Fusarium wilt in the watermelon/wheat companion system.

  18. Looking inside the box: using Raman microspectroscopy to deconstruct microbial biomass stoichiometry one cell at a time

    Science.gov (United States)

    Hall, Edward K.; Singer, Gabriel A.; Pölzl, Marvin; Hämmerle, Ieda; Schwarz, Christian; Daims, Holger; Maixner, Frank; Battin, Tom J.

    2011-01-01

    Stoichiometry of microbial biomass is a key determinant of nutrient recycling in a wide variety of ecosystems. However, little is known about the underlying causes of variance in microbial biomass stoichiometry. This is primarily because of technological constraints limiting the analysis of macromolecular composition to large quantities of microbial biomass. Here, we use Raman microspectroscopy (MS), to analyze the macromolecular composition of single cells of two species of bacteria grown on minimal media over a wide range of resource stoichiometry. We show that macromolecular composition, determined from a subset of identified peaks within the Raman spectra, was consistent with macromolecular composition determined using traditional analytical methods. In addition, macromolecular composition determined by Raman MS correlated with total biomass stoichiometry, indicating that analysis with Raman MS included a large proportion of a cell's total macromolecular composition. Growth phase (logarithmic or stationary), resource stoichiometry and species identity each influenced each organism's macromolecular composition and thus biomass stoichiometry. Interestingly, the least variable peaks in the Raman spectra were those responsible for differentiation between species, suggesting a phylogenetically specific cellular architecture. As Raman MS has been previously shown to be applicable to cells sampled directly from complex environments, our results suggest Raman MS is an extremely useful application for evaluating the biomass stoichiometry of environmental microorganisms. This includes the ability to partition microbial biomass into its constituent macromolecules and increase our understanding of how microorganisms in the environment respond to resource heterogeneity.

  19. The ecological effects of different loading rates of metalaxyl on microbial biomass in unplanted and planted soils under field conditions

    Directory of Open Access Journals (Sweden)

    M. Mansourzadeh

    2016-05-01

    Full Text Available Fungicides are most widely used pesticides in Iran and the world. Application of fungicides may affect the populations and activity of soil microorganisms, particularly fungi, with a consequence for soil fertility and crop growth. In the current study, the effects of different levels of metalaxyl on soil microbial biomass carbon (C and nitrogen (N, microbial biomass C/N ratio and metabolic quotient under field conditions were assessed. Two levels of metalaxyl (30 and 60 kg.ha-1 were applied in planted soils with corn and unplanted calcareous soils, using a split-plots experiment in a completely randomized design with three replications. The C and N contents in soil microbial biomass as well as metabolic quotient were measured at 30 and 90 days after the onset of the experiment. Results showed that in cultivated soils metalaxyl application at 30 kg.ha-1 increased (15-80% significantly (p≤0.01 the amounts of microbial biomass C and N at both intervals (except microbial biomass C at 90 days compared to the control soil (0 kg.ha-1, while in uncultivated soils both microbial biomass C and N reduced by almost 1-34%. Microbial biomass C/N ratios in unplanted soils decreased (15 and 53% with increasing loading rates of metalaxyl, without a clear effect in cultivated soils. On the other hand, metabolic quotient values reduced (48% at 30 and 60 kg.ha-1 metalaxyl in corn-cultivated soils when compared to untreated soils while in uncultivated soils metalaxyl rate at 30 kg.a-1 had the greatest values at 30 days, and increased with increasing the levels of metalaxyl at 90 days. In summary, application of metalaxyl can either reduce or increase soil biological indices, and the direction and changes are depended upon the application rate of metalaxyl, time elapsed since metalaxyl application and the presence or absence of plant.

  20. Seasonal Variation in Soil Microbial Biomass, Bacterial Community Composition and Extracellular Enzyme Activity in Relation to Soil Respiration in a Northern Great Plains Grassland

    Science.gov (United States)

    Wilton, E.; Flanagan, L. B.

    2014-12-01

    Soil respiration rate is affected by seasonal changes in temperature and moisture, but is this a direct effect on soil metabolism or an indirect effect caused by changes in microbial biomass, bacterial community composition and substrate availability? In order to address this question, we compared continuous measurements of soil and plant CO2 exchange made with an automatic chamber system to analyses conducted on replicate soil samples collected on four dates during June-August. Microbial biomass was estimated from substrate-induced respiration rate, bacterial community composition was determined by 16S rRNA amplicon pyrosequencing, and β-1,4-N-acetylglucosaminidase (NAGase) and phenol oxidase enzyme activities were assayed fluorometrically or by absorbance measurements, respectively. Soil microbial biomass declined from June to August in strong correlation with a progressive decline in soil moisture during this time period. Soil bacterial species richness and alpha diversity showed no significant seasonal change. However, bacterial community composition showed a progressive shift over time as measured by Bray-Curtis dissimilarity. In particular, the change in community composition was associated with increasing relative abundance in the alpha and delta classes, and declining abundance of the beta and gamma classes of the Proteobacteria phylum during June-August. NAGase showed a progressive seasonal decline in potential activity that was correlated with microbial biomass and seasonal changes in soil moisture. In contrast, phenol oxidase showed highest potential activity in mid-July near the time of peak soil respiration and ecosystem photosynthesis, which may represent a time of high input of carbon exudates into the soil from plant roots. This input of exudates may stimulate the activity of phenol oxidase, a lignolytic enzyme involved in the breakdown of soil organic matter. These analyses indicated that seasonal change in soil respiration is a complex

  1. Ultrasonic disintegration of microalgal biomass and consequent improvement of bioaccessibility/bioavailability in microbial fermentation.

    Science.gov (United States)

    Jeon, Byong-Hun; Choi, Jeong-A; Kim, Hyun-Chul; Hwang, Jae-Hoon; Abou-Shanab, Reda Ai; Dempsey, Brian A; Regan, John M; Kim, Jung Rae

    2013-01-01

    Microalgal biomass contains a high level of carbohydrates which can be biochemically converted to biofuels using state-of-the-art strategies that are almost always needed to employ a robust pretreatment on the biomass for enhanced energy production. In this study, we used an ultrasonic pretreatment to convert microalgal biomass (Scenedesmus obliquus YSW15) into feasible feedstock for microbial fermentation to produce ethanol and hydrogen. The effect of sonication condition was quantitatively evaluated with emphases on the characterization of carbohydrate components in microalgal suspension and on subsequent production of fermentative bioenergy. Scenedesmus obliquus YSW15 was isolated from the effluent of a municipal wastewater treatment plant. The sonication durations of 0, 10, 15, and 60 min were examined under different temperatures at a fixed frequency and acoustic power resulted in morphologically different states of microalgal biomass lysis. Fermentation was performed to evaluate the bioenergy production from the non-sonicated and sonicated algal biomasses after pretreatment stage under both mesophilic (35°C) and thermophilic (55°C) conditions. A 15 min sonication treatment significantly increased the concentration of dissolved carbohydrates (0.12 g g(-1)), which resulted in an increase of hydrogen/ethanol production through microbial fermentation. The bioconvertibility of microalgal biomass sonicated for 15 min or longer was comparable to starch as a control, indicating a high feasibility of using microalgae for fermentative bioenergy production. Increasing the sonication duration resulted in increases in both algal surface hydrophilicity and electrostatic repulsion among algal debris dispersed in aqueous solution. Scanning electron microscope images supported that ruptured algal cell allowed fermentative bacteria to access the inner space of the cell, evidencing an enhanced bioaccessibility. Sonication for 15 min was the best for fermentative

  2. Microbial Production of Malic Acid from Biofuel-Related Coproducts and Biomass

    Directory of Open Access Journals (Sweden)

    Thomas P. West

    2017-04-01

    Full Text Available The dicarboxylic acid malic acid synthesized as part of the tricarboxylic acid cycle can be produced in excess by certain microorganisms. Although malic acid is produced industrially to a lesser extent than citric acid, malic acid has industrial applications in foods and pharmaceuticals as an acidulant among other uses. Only recently has the production of this organic acid from coproducts of industrial bioprocessing been investigated. It has been shown that malic acid can be synthesized by microbes from coproducts generated during biofuel production. More specifically, malic acid has been shown to be synthesized by species of the fungus Aspergillus on thin stillage, a coproduct from corn-based ethanol production, and on crude glycerol, a coproduct from biodiesel production. In addition, the fungus Ustilago trichophora has also been shown to produce malic acid from crude glycerol. With respect to bacteria, a strain of the thermophilic actinobacterium Thermobifida fusca has been shown to produce malic acid from cellulose and treated lignocellulosic biomass. An alternate method of producing malic acid is to use agricultural biomass converted to syngas or biooil as a substrate for fungal bioconversion. Production of poly(β-l-malic acid by strains of Aureobasidium pullulans from agricultural biomass has been reported where the polymalic acid is subsequently hydrolyzed to malic acid. This review examines applications of malic acid, metabolic pathways that synthesize malic acid and microbial malic acid production from biofuel-related coproducts, lignocellulosic biomass and poly(β-l-malic acid.

  3. Impact of microbial count distributions on human health risk estimates

    DEFF Research Database (Denmark)

    Ribeiro Duarte, Ana Sofia; Nauta, Maarten

    2015-01-01

    Quantitative microbiological risk assessment (QMRA) is influenced by the choice of the probability distribution used to describe pathogen concentrations, as this may eventually have a large effect on the distribution of doses at exposure. When fitting a probability distribution to microbial...... enumeration data, several factors may have an impact on the accuracy of that fit. Analysis of the best statistical fits of different distributions alone does not provide a clear indication of the impact in terms of risk estimates. Thus, in this study we focus on the impact of fitting microbial distributions...... on risk estimates, at two different concentration scenarios and at a range of prevalence levels. By using five different parametric distributions, we investigate whether different characteristics of a good fit are crucial for an accurate risk estimate. Among the factors studied are the importance...

  4. Optimization studies for the bioconversion of Jerusalem artichoke tubers to ethanol and microbial biomass

    Energy Technology Data Exchange (ETDEWEB)

    Margaritis, A.; Bajpai, P.; Cannell, E.

    1981-01-01

    A total of 8 yeast and other microbial cultures were grown in the extract derived from the tubers of Jerusalem artichoke (Helianthus tuberosus) and screened according to the following optimization criteria: rates and yields of ethanol production, rates and yields of biomass production, and percent of original sugars utilized during fermentation. Batch growth kinetic parameters were also determined for the cultures studied. Kluyveromyces marxianus UCD (FST) 55-82 had the highest specific growth rate, 0.41/h, with a high ethanol yield, 88% of theoretical.

  5. Aboveground Forest Biomass Estimation with Landsat and LiDAR Data and Uncertainty Analysis of the Estimates

    Directory of Open Access Journals (Sweden)

    Dengsheng Lu

    2012-01-01

    Full Text Available Landsat Thematic mapper (TM image has long been the dominate data source, and recently LiDAR has offered an important new structural data stream for forest biomass estimations. On the other hand, forest biomass uncertainty analysis research has only recently obtained sufficient attention due to the difficulty in collecting reference data. This paper provides a brief overview of current forest biomass estimation methods using both TM and LiDAR data. A case study is then presented that demonstrates the forest biomass estimation methods and uncertainty analysis. Results indicate that Landsat TM data can provide adequate biomass estimates for secondary succession but are not suitable for mature forest biomass estimates due to data saturation problems. LiDAR can overcome TM’s shortcoming providing better biomass estimation performance but has not been extensively applied in practice due to data availability constraints. The uncertainty analysis indicates that various sources affect the performance of forest biomass/carbon estimation. With that said, the clear dominate sources of uncertainty are the variation of input sample plot data and data saturation problem related to optical sensors. A possible solution to increasing the confidence in forest biomass estimates is to integrate the strengths of multisensor data.

  6. The effect of D123 wheat as a companion crop on soil enzyme activities, microbial biomass and microbial communities in the rhizosphere of watermelon

    Directory of Open Access Journals (Sweden)

    Wei Hui Xu

    2015-09-01

    Full Text Available The growth of watermelon is often threatened by Fusarium oxysporum f. sp. niveum (Fon in successively monocultured soil, which results in economic loss. The objective of this study was to investigate the effect of D123 wheat as a companion crop on soil enzyme activities, microbial biomass and microbial communities in the rhizosphere of watermelon and to explore the relationship between the effect and the incidence of wilt caused by Fon. The results showed that the activities of soil polyphenol oxidase, urease and invertase were increased, the microbial biomass nitrogen (MBN and microbial biomass phosphorus (MBP were significantly increased, and the ratio of MBC/MBN was decreased (P<0.05. Real-time PCR analysis showed that the Fon population declined significantly in the watermelon/wheat companion system compared with the monoculture system (P<0.05. The analysis of microbial communities showed that the relative abundance of microbial communities was changed in the rhizosphere of watermelon. Compared with the monoculture system, the relative abundances of Alphaproteobacteria, Actinobacteria, Gemmatimonadetes and Sordariomycetes were increased, and the relative abundances of Gammaproteobacteria, Sphingobacteria, Cytophagia, Pezizomycetes, and Eurotiomycetes were decreased in the rhizosphere of watermelon in the watermelon/wheat companion system; importantly, the incidence of Fusarium wilt was also decreased in the watermelon/wheat companion system. In conclusion, this study indicated that D123 wheat as a companion crop increased soil enzyme activities and microbial biomass, decreased the Fon population, and changed the relative abundance of microbial communities in the rhizosphere of watermelon, which may be related to the reduction of Fusarium wilt in the watermelon/wheat companion system.

  7. Effects of Biochar on Soil Microbial Biomass after Four Years of Consecutive Application in the North China Plain

    Science.gov (United States)

    Zhang, Qing-zhong; Dijkstra, Feike A.; Liu, Xing-ren; Wang, Yi-ding; Huang, Jian; Lu, Ning

    2014-01-01

    The long term effect of biochar application on soil microbial biomass is not well understood. We measured soil microbial biomass carbon (MBC) and nitrogen (MBN) in a field experiment during a winter wheat growing season after four consecutive years of no (CK), 4.5 (B4.5) and 9.0 t biochar ha−1 yr−1 (B9.0) applied. For comparison, a treatment with wheat straw residue incorporation (SR) was also included. Results showed that biochar application increased soil MBC significantly compared to the CK treatment, and that the effect size increased with biochar application rate. The B9.0 treatment showed the same effect on MBC as the SR treatment. Treatments effects on soil MBN were less strong than for MBC. The microbial biomass C∶N ratio was significantly increased by biochar. Biochar might decrease the fraction of biomass N mineralized (K N), which would make the soil MBN for biochar treatments underestimated, and microbial biomass C∶N ratios overestimated. Seasonal fluctuation in MBC was less for biochar amended soils than for CK and SR treatments, suggesting that biochar induced a less extreme environment for microorganisms throughout the season. There was a significant positive correlation between MBC and soil water content (SWC), but there was no significant correlation between MBC and soil temperature. Biochar amendments may therefore reduce temporal variability in environmental conditions for microbial growth in this system thereby reducing temporal fluctuations in C and N dynamics. PMID:25025330

  8. Effects of biochar on soil microbial biomass after four years of consecutive application in the north China Plain.

    Directory of Open Access Journals (Sweden)

    Qing-zhong Zhang

    Full Text Available The long term effect of biochar application on soil microbial biomass is not well understood. We measured soil microbial biomass carbon (MBC and nitrogen (MBN in a field experiment during a winter wheat growing season after four consecutive years of no (CK, 4.5 (B4.5 and 9.0 t biochar ha(-1 yr(-1 (B9.0 applied. For comparison, a treatment with wheat straw residue incorporation (SR was also included. Results showed that biochar application increased soil MBC significantly compared to the CK treatment, and that the effect size increased with biochar application rate. The B9.0 treatment showed the same effect on MBC as the SR treatment. Treatments effects on soil MBN were less strong than for MBC. The microbial biomass C∶N ratio was significantly increased by biochar. Biochar might decrease the fraction of biomass N mineralized (KN, which would make the soil MBN for biochar treatments underestimated, and microbial biomass C∶N ratios overestimated. Seasonal fluctuation in MBC was less for biochar amended soils than for CK and SR treatments, suggesting that biochar induced a less extreme environment for microorganisms throughout the season. There was a significant positive correlation between MBC and soil water content (SWC, but there was no significant correlation between MBC and soil temperature. Biochar amendments may therefore reduce temporal variability in environmental conditions for microbial growth in this system thereby reducing temporal fluctuations in C and N dynamics.

  9. ESTIMATION OF BIOMASS COMMERCIAL SPROUTS OF Ilex paraguariensis A.ST.-HIL

    Directory of Open Access Journals (Sweden)

    Elisabete Vuaden

    2009-10-01

    Full Text Available This study aimed at developing some models that allow estimating the biomass of commercial green shoots of Ilex paraguariensis after pruning, at 10 years-old. In September 2007, 40 Ilex paraguariensis were pruned. One year after the first pruning, in 2008, they were evaluated dendrometrically and their biomass was determined from the commercial harvest of 16 individuals. To the others, the commercial biomass was estimated by the sum of the biomass of shoots.  The result obtained is that the biomass of commercial sprouts can be estimated as a function of the length of the rolls sprouting, with specific models for sprouts short, simple and compound average sprouts and long sprouts compounds. The models used to estimate the biomass of commercial sprouts using the length sum rolls and rolls of the length as independent variables underestimate the values of biomass with a margin of error of only 2.6%.

  10. Estimating the Heat of Formation of Foodstuffs and Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, Alan K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-11-23

    Calorie estimates for expressing the energy content of food are common, however they are inadequate for the purpose of estimating the chemically defined heat of formation of foodstuffs for two reasons. First, they assume utilization factors by the body.1,2,3 Second, they are usually based on average values for their components. The best way to solve this problem would be to measure the heat of combustion of each material of interest. The heat of formation can then be calculated from the elemental composition and the heats of formation of CO2, H2O, and SO2. However, heats of combustion are not always available. Sometimes elemental analysis only is available, or in other cases, a breakdown into protein, carbohydrates, and lipids. A simple way is needed to calculate the heat of formation from various sorts of data commonly available. This report presents improved correlations for relating the heats of combustion and formation to the elemental composition, moisture content, and ash content. The correlations are also able to calculate heats of combustion of carbohydrates, proteins, and lipids individually, including how they depend on elemental composition. The starting point for these correlations are relationships commonly used to estimate the heat of combustion of fossil fuels, and they have been modified slightly to agree better with the ranges of chemical structures found in foodstuffs and biomass.

  11. Medium activity long-lived nuclear waste; microbial paradise or hadean environment - Evaluation of biomass and impact on redox conditions

    International Nuclear Information System (INIS)

    Albrecht, A.; Libert, M.

    2010-01-01

    near-field biogeochemistry without detailed knowledge of kinetic parameters: The first approach is a mass balance which considers the masses of both the oxidizing and the reducing agents in a single waste cell. In the simplest case only nitrates, sulphates and Fe(0) are considered; nitrates are reduced to N 2 , sulphates to S 2- , and all Fe is oxidised to Fe 3 O 4 , the latter generating hydrogen gas. Of the produced H 2 , 25% serves to reduce nitrates and 55% to reduce sulphates. Further mass balance calculations are underway that consider the direct reaction of nitrates with Fe(0), a reaction for which very little relevant information is available. It is know that nitrate solutions may inhibit corrosion, but they are also known to react with iron. Furthermore, Fe(III), initially present in the engineered barrier or in the host rock and produced as a consequence of Fe(II) oxidation by O 2 during waste cell opening, will also be considered. The second approach combines the previous one with a quantification of free energies, which in turn can be used to form microbial biomass according to the simple relationship 1 g per 64 kJ. With balanced stoichiometric reactions and thermodynamic data at pH 12 first estimates indicate a production of 0.7 kg of biomass per waste container. This is significantly higher than what has been estimated for high-level waste cells, where bacterial activity was modelled to be essentially limited to the first 100 years, when the system is partially characterised by the presence of O 2 . However, these preliminary calculations assume that all nutrients are simultaneously bioavailable and that the energy requirement for microbial biomass production at low pH can be used as a first estimate for higher pH setting. Ongoing work will be presented that considers parameter uncertainties using a Monte Carlo approach, results which allow assessing the upper and lower limits of bacterial production. These values can then be used to quantify the

  12. Exploration of factors limiting biomass estimation by polarimetric radar in tropical forests

    NARCIS (Netherlands)

    Quiñones Fernández, M.J.; Hoekman, D.H.

    2004-01-01

    Direct inversion of radar return signals for forest biomass estimation is limited by signal saturation at medium biomass levels (roughly 150 ton/ha for P-band). Disturbing factors such as forest structural differences-and, notably, at low biomass levels, terrain roughness, and soil moisture

  13. Timber volume and aboveground live tree biomass estimations for landscape analyses in the Pacific Northwest

    Science.gov (United States)

    Xiaoping Zhou; Miles A. Hemstrom

    2010-01-01

    Timber availability, aboveground tree biomass, and changes in aboveground carbon pools are important consequences of landscape management. There are several models available for calculating tree volume and aboveground tree biomass pools. This paper documents species-specific regional equations for tree volume and aboveground live tree biomass estimation that might be...

  14. Estimating root biomass and distribution after fire in a Great Basin woodland using cores and pits

    Science.gov (United States)

    Benjamin M. Rau; Dale W. Johnson; Jeanne C. Chambers; Robert R. Blank; Annmarie Lucchesi

    2009-01-01

    Quantifying root biomass is critical to an estimation and understanding of ecosystem net primary production, biomass partitioning, and belowground competition. We compared 2 methods for determining root biomass: a new soil-coring technique and traditional excavation of quantitative pits. We conducted the study in an existing Joint Fire Sciences demonstration area in...

  15. Aboveground Forest Biomass Estimation with Landsat and LiDAR Data and Uncertainty Analysis of the Estimates

    OpenAIRE

    Dengsheng Lu; Qi Chen; Guangxing Wang; Emilio Moran; Mateus Batistella; Maozhen Zhang; Gaia Vaglio Laurin; David Saah

    2012-01-01

    Landsat Thematic mapper (TM) image has long been the dominate data source, and recently LiDAR has offered an important new structural data stream for forest biomass estimations. On the other hand, forest biomass uncertainty analysis research has only recently obtained sufficient attention due to the difficulty in collecting reference data. This paper provides a brief overview of current forest biomass estimation methods using both TM and LiDAR data. A case study is then presented that demonst...

  16. Estimation of aerial biomass of Lychnophora ericoides (Mart.

    Directory of Open Access Journals (Sweden)

    Brunno Santana de Andrade

    2007-07-01

    Full Text Available For sustainable use of native plant species, knowledge of the amount of harvestable biomass is necessary. This study presents data on allometric relationships of Lychnophora ericoides Mart. (Asteraceae, an extractive resource in the Cerrado region of Brazil. On the Fazenda Água Limpa (15º 45'S, 47º 57'W of the Universidade de Brasilia, 38 individuals of this species were measured in the field, the parts above ground were harvested, separated into components and oven dried. The best regression equations to estimate biomass were geometric and the best fit was between total height and total biomass (r² = 0.923. The economically useful portions, the leaves and branches accounted for approximately 20% of total above ground dry weight, but when used as the dependent variable, the strength of the relationship decreased (r² = 0.694. The relationship between branch diameter and leaf biomass was similar to that between height and leaf dry weight (r² = 0.600. The relation between the number of leaves and their biomass was linear but weak. The development of these equations is the first step towards the implementation of plans for sustainable use of this species.Para o uso sustentável das espécies vegetais nativas o conhecimento da quantidade de biomassa disponível é necessário. O objetivo deste estudo foi verificar as relações alométricas para Lychnophora ericoides Mart., um recurso extrativista importante na região dos Cerrados. Na Fazenda Água Limpa da Universidade de Brasília, 38 indivíduos desta espécie foram medidas no campo, a parte aérea foi cortada, separada em componentes de folhas, galhos e tronco e estas componentes foram secas e pesadas. As melhores equações de regressão para estimar a biomassa foram geométricas e o melhor ajuste foi entre altura total e biomassa total (r² = 0,923. As partes economicamente exploradas, as folhas e ramos, contribuíram com aproximadamente 20% do peso seco total desta espécie, mas a equa

  17. Bioaugmentation for Electricity Generation from Corn Stover Biomass Using Microbial Fuel Cells

    KAUST Repository

    Wang, Xin

    2009-08-01

    Corn stover is usually treated by an energy-intensive or expensive process to extract sugars for bioenergy production. However, it is possible to directly generate electricity from corn stover in microbial fuel cells (MFCs) through the addition of microbial consortia specifically acclimated for biomass breakdown. A mixed culture that was developed to have a high saccharification rate with corn stover was added to singlechamber, air-cathode MFCs acclimated for power production using glucose. The MFC produced a maximum power of 331 mW/ m 2 with the bioaugmented mixed culture and corn stover, compared to 510 mW/m2 using glucose. Denaturing gradient gel electrophoresis (DGGE) showed the communities continued to evolve on both the anode and corn stover biomass over 60 days, with several bacteria identified including Rhodopseudomonas palustris. The use of residual solids from the steam exploded corn stover produced 8% more power (406 mW/m2) than the raw corn stover. These results show that it is possible to directly generate electricity from waste corn stover in MFCs through bioaugmentation using naturally occurring bacteria. © 2009 American Chemical Society.

  18. Responses of microbial biomass carbon and nitrogen to experimental warming: a meta-analysis

    Science.gov (United States)

    Xu, W.; Yuan, W.

    2017-12-01

    Soil microbes play important roles in regulating terrestrial carbon and nitrogen cycling and strongly influence feedbacks of ecosystem to global warming. However, the inconsistent responses of microbial biomass carbon (MBC) and nitrogen (MBN) to experimental warming have been observed, and the response on ratio between MBC and MBN (MBC:MBN) has not been identified. This meta-analysis synthesized the warming experiments at 58 sites globally to investigate the responses of MBC:MBN to climate warming. Our results showed that warming significantly increased MBC by 3.61 ± 0.80% and MBN by 5.85 ± 0.90% and thus decreased the MBC:MBN by 3.34 ± 0.66%. MBC showed positive responses to warming but MBN exhibited negative responses to warming at low warming magnitude (2°C) the results were inverted. The different effects of warming magnitude on microbial biomass resulted from the warming-induced decline in soil moisture and substrate supply. Moreover, MBC and MBN had strong positive responses to warming at the mid-term (3-4 years) or short-term (1-2 years) duration, but the responses tended to decrease at long-term (≥ 5 years) warming duration. This study fills the knowledge gap on the responses of MBC:MBN to warming and may benefit the development of coupled carbon and nitrogen models.

  19. Earthworms (Amynthas spp. increase common bean growth, microbial biomass, and soil respiration

    Directory of Open Access Journals (Sweden)

    Julierme Zimmer Barbosa

    2017-10-01

    Full Text Available Few studies have evaluated the effect of earthworms on plants and biological soil attributes, especially among legumes. The objective of this study was to evaluate the influence of earthworms (Amynthas spp. on growth in the common bean (Phaseolus vulgaris L. and on soil biological attributes. The experiment was conducted in a greenhouse using a completely randomized design with five treatments and eight repetitions. The treatments consisted of inoculation with five different quantities of earthworms of the genus Amynthas (0, 2, 4, 6, and 8 worms per pot. Each experimental unit consisted of a plastic pot containing 4 kg of soil and two common bean plants. The experiment was harvested 38 days after seedling emergence. Dry matter and plant height, soil respiration, microbial respiration, microbial biomass, and metabolic quotient were determined. Earthworm recovery in our study was high in number and mass, with all values above 91.6% and 89.1%, respectively. In addition, earthworm fresh biomass decreased only in the treatment that included eight earthworms per pot. The presence of earthworms increased the plant growth and improved soil biological properties, suggesting that agricultural practices that favor the presence of these organisms can be used to increase the production of common bean, and the increased soil CO2 emission caused by the earthworms can be partially offset by the addition of common bean crop residues to the soil.

  20. Microbial biomass and soil fauna during the decomposition of cover crops in no-tillage system

    Directory of Open Access Journals (Sweden)

    Luciano Colpo Gatiboni

    2011-08-01

    Full Text Available The decomposition of plant residues is a biological process mediated by soil fauna, but few studies have been done evaluating its dynamics in time during the process of disappearance of straw. This study was carried out in Chapecó, in southern Brazil, with the objective of monitoring modifications in soil fauna populations and the C content in the soil microbial biomass (C SMB during the decomposition of winter cover crop residues in a no-till system. The following treatments were tested: 1 Black oat straw (Avena strigosa Schreb.; 2 Rye straw (Secale cereale L.; 3 Common vetch straw (Vicia sativa L.. The cover crops were grown until full flowering and then cut mechanically with a rolling stalk chopper. The soil fauna and C content in soil microbial biomass (C SMB were assessed during the period of straw decomposition, from October 2006 to February 2007. To evaluate C SMB by the irradiation-extraction method, soil samples from the 0-10 cm layer were used, collected on eight dates, from before until 100 days after residue chopping. The soil fauna was collected with pitfall traps on seven dates up to 85 days after residue chopping. The phytomass decomposition of common vetch was faster than of black oat and rye residues. The C SMB decreased during the process of straw decomposition, fastest in the treatment with common vetch. In the common vetch treatment, the diversity of the soil fauna was reduced at the end of the decomposition process.

  1. Tropical forest plantation biomass estimation using RADARSAT-SAR and TM data of south china

    Science.gov (United States)

    Wang, Chenli; Niu, Zheng; Gu, Xiaoping; Guo, Zhixing; Cong, Pifu

    2005-10-01

    Forest biomass is one of the most important parameters for global carbon stock model yet can only be estimated with great uncertainties. Remote sensing, especially SAR data can offers the possibility of providing relatively accurate forest biomass estimations at a lower cost than inventory in study tropical forest. The goal of this research was to compare the sensitivity of forest biomass to Landsat TM and RADARSAT-SAR data and to assess the efficiency of NDVI, EVI and other vegetation indices in study forest biomass based on the field survey date and GIS in south china. Based on vegetation indices and factor analysis, multiple regression and neural networks were developed for biomass estimation for each species of the plantation. For each species, the better relationships between the biomass predicted and that measured from field survey was obtained with a neural network developed for the species. The relationship between predicted and measured biomass derived from vegetation indices differed between species. This study concludes that single band and many vegetation indices are weakly correlated with selected forest biomass. RADARSAT-SAR Backscatter coefficient has a relatively good logarithmic correlation with forest biomass, but neither TM spectral bands nor vegetation indices alone are sufficient to establish an efficient model for biomass estimation due to the saturation of bands and vegetation indices, multiple regression models that consist of spectral and environment variables improve biomass estimation performance. Comparing with TM, a relatively well estimation result can be achieved by RADARSAT-SAR, but all had limitations in tropical forest biomass estimation. The estimation results obtained are not accurate enough for forest management purposes at the forest stand level. However, the approximate volume estimates derived by the method can be useful in areas where no other forest information is available. Therefore, this paper provides a better

  2. Soil microbial biomass under different management and tillage systems of permanent intercropped cover species in an orange orchard

    Directory of Open Access Journals (Sweden)

    Elcio Liborio Balota

    2011-12-01

    Full Text Available To mitigate soil erosion and enhance soil fertility in orange plantations, the permanent protection of the inter-rows by cover species has been suggested. The objective of this study was to evaluate alterations in the microbial biomass, due to different soil tillage systems and intercropped cover species between rows of orange trees. The soil of the experimental area previously used as pasture (Brachiaria humidicola was an Ultisol (Typic Paleudult originating from Caiuá sandstone in the northwestern part of the State of Paraná, Brazil. Two soil tillage systems were evaluated: conventional tillage (CT in the entire area and strip tillage (ST (strip width 2 m, in combination with different ground cover management systems. The citrus cultivar 'Pera' orange (Citrus sinensis grafted onto 'Rangpur' lime rootstock was used. Soil samples were collected after five years of treatment from a depth of 0-15 cm, under the tree canopy and in the inter-row, in the following treatments: (1 CT and an annual cover crop with the leguminous species Calopogonium mucunoides; (2 CT and a perennial cover crop with the leguminous peanut Arachis pintoi; (3 CT and an evergreen cover crop with Bahiagrass Paspalum notatum; (4 CT and a cover crop with spontaneous Brachiaria humidicola grass vegetation; and (5 ST and maintenance of the remaining grass (pasture of Brachiaria humidicola. Soil tillage and the different cover species influenced the microbial biomass, both under the tree canopy and in the inter-row. The cultivation of brachiaria increased C and N in the microbial biomass, while bahiagrass increased P in the microbial biomass. The soil microbial biomass was enriched in N and P by the presence of ground cover species and according to the soil P content. The grass species increased C, N and P in the soil microbial biomass from the inter-row more than leguminous species.

  3. The Spatial Distribution of Forest Biomass in the Brazilian Amazon: A Comparison of Estimates

    Science.gov (United States)

    Houghton, R. A.; Lawrence, J. L.; Hackler, J. L.; Brown, S.

    2001-01-01

    The amount of carbon released to the atmosphere as a result of deforestation is determined, in part, by the amount of carbon held in the biomass of the forests converted to other uses. Uncertainty in forest biomass is responsible for much of the uncertainty in current estimates of the flux of carbon from land-use change. We compared several estimates of forest biomass for the Brazilian Amazon, based on spatial interpolations of direct measurements, relationships to climatic variables, and remote sensing data. We asked three questions. First, do the methods yield similar estimates? Second, do they yield similar spatial patterns of distribution of biomass? And, third, what factors need most attention if we are to predict more accurately the distribution of forest biomass over large areas? Amazonian forests (including dead and below-ground biomass) vary by more than a factor of two, from a low of 39 PgC to a high of 93 PgC. Furthermore, the estimates disagree as to the regions of high and low biomass. The lack of agreement among estimates confirms the need for reliable determination of aboveground biomass over large areas. Potential methods include direct measurement of biomass through forest inventories with improved allometric regression equations, dynamic modeling of forest recovery following observed stand-replacing disturbances (the approach used in this research), and estimation of aboveground biomass from airborne or satellite-based instruments sensitive to the vertical structure plant canopies.

  4. Spatial distribution of microbial biomass, activity, community structure, and the biodegradation of linear alkylbenzene sulfonate (LAS) and linear alcohol ethoxylate (LAE) in the subsurface.

    Science.gov (United States)

    Federle, T W; Ventullo, R M; White, D C

    1990-12-01

    The vertical distribution of microbial biomass, activity, community structure and the mineralization of xenobiotic chemicals was examined in two soil profiles in northern Wisconsin. One profile was impacted by infiltrating wastewater from a laundromat, while the other served as a control. An unconfined aquifer was present 14 meters below the surface at both sites. Biomass and community structure were determined by acridine orange direct counts and measuring concentrations of phospholipid-derived fatty acids (PLFA). Microbial activity was estimated by measuring fluorescein diacetate (FDA) hydrolysis, thymidine incorporation into DNA, and mixed amino acid (MAA) mineralization. Mineralization kinetics of linear alkylbenzene sulfonate (LAS) and linear alcohol ethoxylate (LAE) were determined at each depth. Except for MAA mineralization rates, measures of microbial biomass and activity exhibited similar patterns with depth. PLFA concentration and rates of FDA hydrolysis and thymidine incorporation decreased 10-100 fold below 3 m and then exhibited little variation with depth. Fungal fatty acid markers were found at all depths and represented from 1 to 15% of the total PLFAs. The relative proportion of tuberculostearic acid (TBS), an actinomycete marker, declined with depth and was not detected in the saturated zone. The profile impacted by wastewater exhibited higher levels of PLFA but a lower proportion of TBS than the control profile. This profile also exhibited faster rates of FDA hydrolysis and amino acid mineralization at most depths. LAS was mineralized in the upper 2 m of the vadose zone and in the saturated zone of both profiles. Little or no LAS biodegradation occurred at depths between 2 and 14 m. LAE was mineralized at all depths in both profiles, and the mineralization rate exhibited a similar pattern with depth as biomass and activity measurements. In general, biomass and biodegradative activities were much lower in groundwater than in soil samples obtained

  5. Field and lab conditions alter microbial enzyme and biomass dynamics driving decomposition of the same leaf litter

    Directory of Open Access Journals (Sweden)

    Zachary L Rinkes

    2013-09-01

    Full Text Available Fluctuations in climate and edaphic factors influence field decomposition rates and preclude a complete understanding of how microbial communities respond to plant litter quality. In contrast, laboratory microcosms isolate the intrinsic effects of litter chemistry and microbial community from extrinsic effects of environmental variation. Used together, these paired approaches provide mechanistic insights to decomposition processes. In order to elucidate the microbial mechanisms underlying how environmental conditions alter the trajectory of decay, we characterized microbial biomass, respiration, enzyme activities, and nutrient dynamics during early (< 10% mass loss, mid- (10-40% mass loss, and late (> 40% mass loss decay in parallel field and laboratory litter bag incubations for deciduous tree litters with varying recalcitrance (dogwood < maple < maple-oak mixture < oak. In the field, mass loss was minimal (< 10% over the first 50 days (January-February, even for labile litter types, despite above-freezing soil temperatures and adequate moisture during these winter months. In contrast, microcosms displayed high C mineralization rates in the first week. During mid-decay, the labile dogwood and maple litters in the field had higher mass loss per unit enzyme activity than the lab, possibly due to leaching of soluble compounds. Microbial biomass to litter mass (B:C ratios peaked in the field during late decay, but B:C ratios declined between mid- and late decay in the lab. Thus, microbial biomass did not have a consistent relationship with litter quality between studies. Higher oxidative enzyme activities in oak litters in the field, and higher nitrogen (N accumulation in the lab microcosms occurred in late decay. We speculate that elevated N suppressed fungal activity and/or biomass in microcosms. Our results suggest that differences in microbial biomass and enzyme dynamics alter the decay trajectory of the same leaf litter under field and lab

  6. Field and lab conditions alter microbial enzyme and biomass dynamics driving decomposition of the same leaf litter.

    Science.gov (United States)

    Rinkes, Zachary L; Sinsabaugh, Robert L; Moorhead, Daryl L; Grandy, A Stuart; Weintraub, Michael N

    2013-01-01

    Fluctuations in climate and edaphic factors influence field decomposition rates and preclude a complete understanding of how microbial communities respond to plant litter quality. In contrast, laboratory microcosms isolate the intrinsic effects of litter chemistry and microbial community from extrinsic effects of environmental variation. Used together, these paired approaches provide mechanistic insights to decomposition processes. In order to elucidate the microbial mechanisms underlying how environmental conditions alter the trajectory of decay, we characterized microbial biomass, respiration, enzyme activities, and nutrient dynamics during early (40% mass loss) decay in parallel field and laboratory litter bag incubations for deciduous tree litters with varying recalcitrance (dogwood litter types, despite above-freezing soil temperatures and adequate moisture during these winter months. In contrast, microcosms displayed high C mineralization rates in the first week. During mid-decay, the labile dogwood and maple litters in the field had higher mass loss per unit enzyme activity than the lab, possibly due to leaching of soluble compounds. Microbial biomass to litter mass (B:C) ratios peaked in the field during late decay, but B:C ratios declined between mid- and late decay in the lab. Thus, microbial biomass did not have a consistent relationship with litter quality between studies. Higher oxidative enzyme activities in oak litters in the field, and higher nitrogen (N) accumulation in the lab microcosms occurred in late decay. We speculate that elevated N suppressed fungal activity and/or biomass in microcosms. Our results suggest that differences in microbial biomass and enzyme dynamics alter the decay trajectory of the same leaf litter under field and lab conditions.

  7. Effects of fire on soil nitrogen dynamics and microbial biomass in savannas of Central Brazil

    Directory of Open Access Journals (Sweden)

    Nardoto Gabriela Bielefeld

    2003-01-01

    Full Text Available The objective of this work was to study the effects of fire on net N mineralization and soil microbial biomass in burned and unburned cerrado stricto sensu sites. The study was carried out from April 1998 to April 2000. The pH values were significantly higher in the burned site while soil moisture content was significantly higher in the unburned site (P<0.05. The soil C/N ratio was 22/1 and the available NO3-N ranged between 1.5 and 2.8 mg kg-¹ dry weight. However, the NH4-N concentration ranged between 3 and 34 mg kg-1 dry weight in the burned site and between 3 and 22 mg kg-1 dry weight in the unburned site. The NH4-N increased after fire, but no significant changes were observed for NO3-N (P<0.05. The NO3-N accumulation occurred in short periods during the rainy season. The rates of net N mineralization increased during the rainy season while reductions in soil microbial biomass were observed at both sites. This suggested that the peak in microbial activities occurred with the first rain events, with an initial net immobilization followed by net mineralization. Both sites presented the same pattern for mineralization/immobilization, however, the amount of inorganic-N cycled annually in unburned site was 14.7 kg ha-1 per year while the burned site presented only 3.8 kg ha-¹ of inorganic-N, one year after the burning.

  8. Qualitative Analysis of Microbial Dynamics during Anaerobic Digestion of Microalgal Biomass in a UASB Reactor

    Directory of Open Access Journals (Sweden)

    Anna Doloman

    2017-01-01

    Full Text Available Anaerobic digestion (AD is a microbiologically coordinated process with dynamic relationships between bacterial players. Current understanding of dynamic changes in the bacterial composition during the AD process is incomplete. The objective of this research was to assess changes in bacterial community composition that coordinates with anaerobic codigestion of microalgal biomass cultivated on municipal wastewater. An upflow anaerobic sludge blanket reactor was used to achieve high rates of microalgae decomposition and biogas production. Samples of the sludge were collected throughout AD and extracted DNA was subjected to next-generation sequencing using methanogen mcrA gene specific and universal bacterial primers. Analysis of the data revealed that samples taken at different stages of AD had varying bacterial composition. A group consisting of Bacteroidales, Pseudomonadales, and Enterobacteriales was identified to be putatively responsible for the hydrolysis of microalgal biomass. The methanogenesis phase was dominated by Methanosarcina mazei. Results of observed changes in the composition of microbial communities during AD can be used as a road map to stimulate key bacterial species identified at each phase of AD to increase yield of biogas and rate of substrate decomposition. This research demonstrates a successful exploitation of methane production from microalgae without any biomass pretreatment.

  9. Qualitative Analysis of Microbial Dynamics during Anaerobic Digestion of Microalgal Biomass in a UASB Reactor

    Science.gov (United States)

    Doloman, Anna; Soboh, Yousef; Walters, Andrew J.; Sims, Ronald C.

    2017-01-01

    Anaerobic digestion (AD) is a microbiologically coordinated process with dynamic relationships between bacterial players. Current understanding of dynamic changes in the bacterial composition during the AD process is incomplete. The objective of this research was to assess changes in bacterial community composition that coordinates with anaerobic codigestion of microalgal biomass cultivated on municipal wastewater. An upflow anaerobic sludge blanket reactor was used to achieve high rates of microalgae decomposition and biogas production. Samples of the sludge were collected throughout AD and extracted DNA was subjected to next-generation sequencing using methanogen mcrA gene specific and universal bacterial primers. Analysis of the data revealed that samples taken at different stages of AD had varying bacterial composition. A group consisting of Bacteroidales, Pseudomonadales, and Enterobacteriales was identified to be putatively responsible for the hydrolysis of microalgal biomass. The methanogenesis phase was dominated by Methanosarcina mazei. Results of observed changes in the composition of microbial communities during AD can be used as a road map to stimulate key bacterial species identified at each phase of AD to increase yield of biogas and rate of substrate decomposition. This research demonstrates a successful exploitation of methane production from microalgae without any biomass pretreatment. PMID:29259629

  10. Biomass production from electricity using ammonia as an electron carrier in a reverse microbial fuel cell.

    Directory of Open Access Journals (Sweden)

    Wendell O Khunjar

    Full Text Available The storage of renewable electrical energy within chemical bonds of biofuels and other chemicals is a route to decreasing petroleum usage. A critical challenge is the efficient transfer of electrons into a biological host that can covert this energy into high energy organic compounds. In this paper, we describe an approach whereby biomass is grown using energy obtained from a soluble mediator that is regenerated electrochemically. The net result is a separate-stage reverse microbial fuel cell (rMFC that fixes CO₂ into biomass using electrical energy. We selected ammonia as a low cost, abundant, safe, and soluble redox mediator that facilitated energy transfer to biomass. Nitrosomonas europaea, a chemolithoautotroph, was used as the biocatalyst due to its inherent capability to utilize ammonia as its sole energy source for growth. An electrochemical reactor was designed for the regeneration of ammonia from nitrite, and current efficiencies of 100% were achieved. Calculations indicated that overall bioproduction efficiency could approach 2.7±0.2% under optimal electrolysis conditions. The application of chemolithoautotrophy for industrial bioproduction has been largely unexplored, and results suggest that this and related rMFC platforms may enable biofuel and related biochemical production.

  11. Photosynthetic microbial desalination cells (PMDCs) for clean energy, water and biomass production.

    Science.gov (United States)

    Kokabian, Bahareh; Gude, Veera Gnaneswar

    2013-12-01

    Current microbial desalination cell (MDC) performances are evaluated with chemical catalysts such as ferricyanide, platinum catalyzed air-cathodes or aerated cathodes. All of these methods improve power generation potential in MDCs, however, they are not preferable for large scale applications due to cost, energy and environmental toxicity issues. In this study, performance of microbial desalination cells with an air cathode and an algae biocathode (Photosynthetic MDC - PMDC) were evaluated, both under passive conditions (no mechanical aeration or mixing). The results indicate that passive algae biocathodes perform better than air cathodes and enhance COD removal and utilize treated wastewater as the growth medium to obtain valuable biomass for high value bioproducts. Maximum power densities of 84 mW m(-3) (anode volume) or 151 mW m(-3) (biocathode volume) and a desalination rate of 40% were measured with 0.9 : 1 : 0.5 volumetric ratios of anode, desalination and algae biocathode chambers respectively. This first proof-of-concept study proves that the passive mechanisms can be beneficial in enhancing the sustainability of microbial desalination cells.

  12. A stepwise-cluster microbial biomass inference model in food waste composting

    International Nuclear Information System (INIS)

    Sun Wei; Huang, Guo H.; Zeng Guangming; Qin Xiaosheng; Sun Xueling

    2009-01-01

    A stepwise-cluster microbial biomass inference (SMI) model was developed through introducing stepwise-cluster analysis (SCA) into composting process modeling to tackle the nonlinear relationships among state variables and microbial activities. The essence of SCA is to form a classification tree based on a series of cutting or mergence processes according to given statistical criteria. Eight runs of designed experiments in bench-scale reactors in a laboratory were constructed to demonstrate the feasibility of the proposed method. The results indicated that SMI could help establish a statistical relationship between state variables and composting microbial characteristics, where discrete and nonlinear complexities exist. Significance levels of cutting/merging were provided such that the accuracies of the developed forecasting trees were controllable. Through an attempted definition of input effects on the output in SMI, the effects of the state variables on thermophilic bacteria were ranged in a descending order as: Time (day) > moisture content (%) > ash content (%, dry) > Lower Temperature (deg. C) > pH > NH 4 + -N (mg/Kg, dry) > Total N (%, dry) > Total C (%, dry); the effects on mesophilic bacteria were ordered as: Time > Upper Temperature (deg. C) > Total N > moisture content > NH 4 + -N > Total C > pH. This study made the first attempt in applying SCA to mapping the nonlinear and discrete relationships in composting processes.

  13. Nitrogen fractions in the microbial biomass in soils of southern Brazil

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    F. A.O. Camargo

    1999-03-01

    Full Text Available The reaction of nitrogen compounds with ninhydrin can be used as an indicator of cytoplasmic materials released from microbial cells killed by fumigation. Total-N, ninhydrin-reactive-N (NR-N, ammonium-N (A-N, and α-amino-N in the microbial biomass of soils from the State of Rio Grande do Sul, Brazil, were determined, in 1996, in 0.5 mol L-1 K2SO4 extracts of fumigated and non-fumigated soils. Total-N varied from 20.3 to 104.4 mg kg-1 and the ninhydrin-reactive-N corresponded, in average, to 27% of this. The ninhydrin-reactive-N was made up of 67% ammonium-N and 33% aminoacids with the amino group at the α-carbon position. It was concluded that colorimetric analysis of NR-N and A-N may be used as a direct measure of microbial N in soil. This simple and rapid procedure is adequate for routine analyses.

  14. Microbial respiration, but not biomass, responded linearly to increasing light fraction organic matter input: Consequences for carbon sequestration.

    Science.gov (United States)

    Rui, Yichao; Murphy, Daniel V; Wang, Xiaoli; Hoyle, Frances C

    2016-10-18

    Rebuilding 'lost' soil carbon (C) is a priority in mitigating climate change and underpinning key soil functions that support ecosystem services. Microorganisms determine if fresh C input is converted into stable soil organic matter (SOM) or lost as CO 2 . Here we quantified if microbial biomass and respiration responded positively to addition of light fraction organic matter (LFOM, representing recent inputs of plant residue) in an infertile semi-arid agricultural soil. Field trial soil with different historical plant residue inputs [soil C content: control (tilled) = 9.6 t C ha -1 versus tilled + plant residue treatment (tilled + OM) = 18.0 t C ha -1 ] were incubated in the laboratory with a gradient of LFOM equivalent to 0 to 3.8 t C ha -1 (0 to 500% LFOM). Microbial biomass C significantly declined under increased rates of LFOM addition while microbial respiration increased linearly, leading to a decrease in the microbial C use efficiency. We hypothesise this was due to insufficient nutrients to form new microbial biomass as LFOM input increased the ratio of C to nitrogen, phosphorus and sulphur of soil. Increased CO 2 efflux but constrained microbial growth in response to LFOM input demonstrated the difficulty for C storage in this environment.

  15. Microbial biomass and viral infections of heterotrophic prokaryotes in the sub-surface layer of the central Arctic Ocean

    Science.gov (United States)

    Steward, Grieg F.; Fandino, Laura B.; Hollibaugh, James T.; Whitledge, Terry E.; Azam, Farooq

    2007-10-01

    Seawater samples were collected for microbial analyses between 55 and 235 m depth across the Arctic Ocean during the SCICEX 97 expedition (03 September-02 October 1997) using a nuclear submarine as a research platform. Abundances of prokaryotes (range 0.043-0.47×10 9 dm -3) and viruses (range 0.68-11×10 9 dm -3) were correlated ( r=0.66, n=150) with an average virus:prokaryote ratio of 26 (range 5-70). Biomass of prokaryotes integrated from 55 to 235 m ranged from 0.27 to 0.85 g C m -2 exceeding that of phytoplankton (0.005-0.2 g C m -2) or viruses (0.02-0.05 g C m -2) over the same depth range by an order of magnitude on average. Using transmission electron microscopy (TEM), we estimated that 0.5% of the prokaryote community on average (range 0-1.4%) was visibly infected with viruses, which suggests that very little of prokaryotic secondary production was lost due to viral lysis. Intracellular viruses ranged from 5 to >200/cell, with an average apparent burst size of 45±38 (mean±s.d.; n=45). TEM also revealed the presence of putative metal-precipitating bacteria in 8 of 13 samples, which averaged 0.3% of the total prokaryote community (range 0-1%). If these prokaryotes are accessible to protistan grazers, the Fe and Mn associated with their capsules might be an important source of trace metals to the planktonic food web. After combining our abundance and mortality data with data from the literature, we conclude that the biomass of prokaryoplankton exceeds that of phytoplankton when averaged over the upper 250 m of the central Arctic Ocean and that the fate of this biomass is poorly understood.

  16. Assimilable organic carbon (AOC) in soil water extracts using Vibrio harveyi BB721 and its implication for microbial biomass.

    Science.gov (United States)

    Ma, Jincai; Ibekwe, A Mark; Wang, Haizhen; Xu, Jianming; Leddy, Menu; Yang, Ching-Hong; Crowley, David E

    2012-01-01

    Assimilable organic carbon (AOC) is commonly used to measure the growth potential of microorganisms in water, but has not yet been investigated for measuring microbial growth potential in soils. In this study, a simple, rapid, and non-growth based assay to determine AOC in soil was developed using a naturally occurring luminous strain Vibrio harveyi BB721 to determine the fraction of low molecular weight organic carbon in soil water extract. Calibration of the assay was achieved by measuring the luminescence intensity of starved V. harveyi BB721 cells in the late exponential phase with a concentration range from 0 to 800 µg l(-1) glucose (equivalent to 0-16.0 mg glucose C kg(-1) soil) with the detection limit of 10 µg l(-1) equivalent to 0.20 mg glucose C kg(-1) soil. Results showed that bioluminescence was proportional to the concentration of glucose added to soil. The luminescence intensity of the cells was highly pH dependent and the optimal pH was about 7.0. The average AOC concentration in 32 soils tested was 2.9±2.2 mg glucose C kg(-1). Our data showed that AOC levels in soil water extracts were significantly correlated (Pgrowth bioluminescence based assay. Understanding the levels of AOC in soil water extract provides new insights into our ability to estimate the most available carbon pool to bacteria in soil that may be easily assimilated into cells for many metabolic processes and suggest possible the links between AOC, microbial regrowth potential, and microbial biomass in soils.

  17. D:L-AMINO Acids and the Turnover of Microbial Biomass

    Science.gov (United States)

    Lomstein, B. A.; Braun, S.; Mhatre, S. S.; Jørgensen, B. B.

    2015-12-01

    Decades of ocean drilling have demonstrated wide spread microbial life in deep sub-seafloor sediment, and surprisingly high microbial cell numbers. Despite the ubiquity of life in the deep biosphere, the large community sizes and the low energy fluxes in the vast buried ecosystem are still poorly understood. It is not know whether organisms of the deep biosphere are specifically adapted to extremely low energy fluxes or whether most of the observed cells are in a maintenance state. Recently we developed and applied a new culture independent approach - the D:L-amino acid model - to quantify the turnover times of living microbial biomass, microbial necromass and mean metabolic rates. This approach is based on the built-in molecular clock in amino acids that very slowly undergo chemical racemization until they reach an even mixture of L- and D- forms, unless microorganisms spend energy to keep them in the L-form that dominates in living organisms. The approach combines sensitive analyses of amino acids, the unique bacterial endospore marker (dipicolinic acid) with racemization dynamics of stereo-isomeric amino acids. Based on a heating experiment, we recently reported kinetic parameters for racemization of aspartic acid, glutamic acid, serine and alanine in bulk sediment from Aarhus Bay, Denmark. The obtained racemization rate constants were faster than the racemization rate constants of free amino acids, which we have previously applied in Holocene sediment from Aarhus Bay and in up to 10 mio yr old sediment from ODP Leg 201. Another important input parameter for the D:L-amino acid model is the cellular carbon content. It has recently been suggested that the cellular carbon content most likely is lower than previously thought. In recognition of these new findings, previously published data based on the D:L-amino acid model were recalculated and will be presented together with new data from an Arctic Holocene setting with constant sub-zero temperatures.

  18. Estimating volume, biomass, and potential emissions of hand-piled fuels

    Science.gov (United States)

    Clinton S. Wright; Cameron S. Balog; Jeffrey W. Kelly

    2009-01-01

    Dimensions, volume, and biomass were measured for 121 hand-constructed piles composed primarily of coniferous (n = 63) and shrub/hardwood (n = 58) material at sites in Washington and California. Equations using pile dimensions, shape, and type allow users to accurately estimate the biomass of hand piles. Equations for estimating true pile volume from simple geometric...

  19. Comparing algorithms for estimating foliar biomass of conifers in the Pacific Northwest

    Science.gov (United States)

    Crystal L. Raymond; Donald. McKenzie

    2013-01-01

    Accurate estimates of foliar biomass (FB) are important for quantifying carbon storage in forest ecosystems, but FB is not always reported in regional or national inventories. Foliar biomass also drives key ecological processes in ecosystem models. Published algorithms for estimating FB in conifer species of the Pacific Northwest can yield signifi cantly different...

  20. Estimation and mapping of above ground biomass and carbon of ...

    African Journals Online (AJOL)

    USER

    1Department of Geomatics and Land Management, Makerere University, P.O. Box 7062 ... Biomass is an important parameter for bioenergy modelling, food security, ... –Kyoto climate change agreement on reducing emissions from deforestation and ... the nature of terrain can also affect the amounts of biomass and carbon ...

  1. Soil respiration, microbial biomass and exoenzyme activity in switchgrass stands under nitrogen fertilization management and climate warming.

    Science.gov (United States)

    Jian, S.; Li, J.; de Koff, J.; Celada, S.; Mayes, M. A.; Wang, G.; Guo, C.

    2016-12-01

    Switchgrass (Panicum virgatum L.), as a model bioenergy crop, received nitrogen fertilizers for increasing its biomass yields. Studies rarely investigate the interactive effects of nitrogen fertilization and climate warming on soil microbial activity and carbon cycling in switchgrass cropping systems. Enhanced nitrogen availability under fertilization can alter rates of soil organic matter decomposition and soil carbon emissions to the atmosphere and thus have an effect on climate change. Here, we assess soil CO2 emission, microbial biomass and exoenzyme activities in two switchgrass stands with no fertilizer and 60 lbs N / acre. Soils were incubated at 15 ºC and 20 ºC for 180-day. Dry switchgrass plant materials were added to incubation jars and the 13C stable isotopic probing technique was used to monitor soil CO2 respiration derived from relatively labile litter and indigenous soil. Measurements of respiration, δ13C of respiration, microbial biomass carbon and exoenzyme activity were performed on days 1, 5, 10, 15, 30, 60, 90, 120, 150 and 180. Soil respiration rate was greater in the samples incubated at 20 ºC as compared to those incubated at 15 ºC. Exoenzyme activities were significantly altered by warming, litter addition and nitrogen fertilization. There was a significant interactive effect of nitrogen fertilization and warming on the proportion of CO2 respired from soils such that nitrogen fertilization enhanced warming-induced increase by 12.0% (Pmineralization. Fertilization increased soil microbial biomass carbon at both temperatures (9.0% at 15 ºC and 14.5% at 20 ºC). Our preliminary analysis suggested that warming effects on enhanced soil respiration can be further increased with elevated fertilizer input via greater microbial biomass and exoenzyme activity. In addition to greater biomass yield under N fertilization, this study informs potential soil carbon loss from stimulated soil respiration under nitrogen fertilization and warming in

  2. SAFARI 2000 1-Degree Estimates of Burned Biomass, Area, and Emissions, 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — A new method is used to generate spatial estimates of monthly averaged biomass burned area and spatial and temporal estimates of trace gas and aerosol emissions from...

  3. Non-Destructive, Laser-Based Individual Tree Aboveground Biomass Estimation in a Tropical Rainforest

    Directory of Open Access Journals (Sweden)

    Muhammad Zulkarnain Abd Rahman

    2017-03-01

    Full Text Available Recent methods for detailed and accurate biomass and carbon stock estimation of forests have been driven by advances in remote sensing technology. The conventional approach to biomass estimation heavily relies on the tree species and site-specific allometric equations, which are based on destructive methods. This paper introduces a non-destructive, laser-based approach (terrestrial laser scanner for individual tree aboveground biomass estimation in the Royal Belum forest reserve, Perak, Malaysia. The study area is in the state park, and it is believed to be one of the oldest rainforests in the world. The point clouds generated for 35 forest plots, using the terrestrial laser scanner, were geo-rectified and cleaned to produce separate point clouds for individual trees. The volumes of tree trunks were estimated based on a cylinder model fitted to the point clouds. The biomasses of tree trunks were calculated by multiplying the volume and the species wood density. The biomasses of branches and leaves were also estimated based on the estimated volume and density values. Branch and leaf volumes were estimated based on the fitted point clouds using an alpha-shape approach. The estimated individual biomass and the total above ground biomass were compared with the aboveground biomass (AGB value estimated using existing allometric equations and individual tree census data collected in the field. The results show that the combination of a simple single-tree stem reconstruction and wood density can be used to estimate stem biomass comparable to the results usually obtained through existing allometric equations. However, there are several issues associated with the data and method used for branch and leaf biomass estimations, which need further improvement.

  4. Microbial biomass and carbon mineralization in agricultural soils as affected by pesticide addition.

    Science.gov (United States)

    Kumar, Anjani; Nayak, A K; Shukla, Arvind K; Panda, B B; Raja, R; Shahid, Mohammad; Tripathi, Rahul; Mohanty, Sangita; Rath, P C

    2012-04-01

    A laboratory study was conducted with four pesticides, viz. a fungicide (carbendazim), two insecticides (chlorpyrifos and cartap hydrochloride) and an herbicide (pretilachlor) applied to a sandy clay loam soil at a field rate to determine their effect on microbial biomass carbon (MBC) and carbon mineralization (C(min)). The MBC content of soil increased with time up to 30 days in cartap hydrochloride as well as chlorpyrifos treated soil. Thereafter, it decreased and reached close to the initial level by 90th day. However, in carbendazim treated soil, the MBC showed a decreasing trend up to 45 days and subsequently increased up to 90 days. In pretilachlor treated soil, MBC increased through the first 15 days, and thereafter decreased to the initial level. Application of carbendazim, chlorpyrifos and cartap hydrochloride decreased C(min) for the first 30 days and then increased afterwards, while pretilachlor treated soil showed an increasing trend.

  5. Enzyme activities and microbial biomass in topsoil layer during spontaneous succession in spoil heaps after brown coal mining

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Petr; Trögl, Josef; Frouz, Jan; Šnajdr, Jaroslav; Valášková, Vendula; Merhautová, Věra; Cajthaml, Tomáš; Herinková, Jana

    2008-01-01

    Roč. 40, č. 9 (2008), s. 2107-2115 ISSN 0038-0717 R&D Projects: GA MŠk LC06066 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z60660521 Keywords : enzyme activity * lignocellulose * microbial biomass Subject RIV: EH - Ecology, Behaviour Impact factor: 2.926, year: 2008

  6. Soil-derived microbial consortia enriched with different plant biomass reveal distinct players acting in lignocellulose degradation

    NARCIS (Netherlands)

    de Lima Brossi, Maria Julia; Jiménez Avella, Diego; Cortes Tolalpa, Larisa; van Elsas, Jan

    Here, we investigated how different plant biomass, and-for one substrate-pH, drive the composition of degrader microbial consortia. We bred such consortia from forest soil, incubated along nine aerobic sequential - batch enrichments with wheat straw (WS1, pH 7.2; WS2, pH 9.0), switchgrass (SG, pH

  7. Effects of phosphorus addition on soil microbial biomass and community composition in three forest types in tropical China

    DEFF Research Database (Denmark)

    Liu, Lei; Gundersen, Per; Zhang, Tao

    2012-01-01

    Elevated nitrogen (N) deposition in humid tropical regions may aggravate phosphorus (P) deficiency in forest on old weathered soil found in these regions. From January 2007 to August 2009, we studied the responses of soil microbial biomass and community composition to P addition (in two monthly...

  8. Microbial biomass and bacterial functional diversity in forest soils: effects of organic matter removal, compaction, and vegetation control

    Science.gov (United States)

    Qingchao Li; H. Lee Allen; Arthur G. Wollum

    2004-01-01

    The effects of organic matter removal, soil compaction, and vegetation control on soil microbial biomass carbon, nitrogen, C-to-N ratio, and functional diversity were examined in a 6-year loblolly pine plantation on a Coastal Plain site in eastern North Carolina, USA. This experimental plantation was established as part of the US Forest Service's Long Term Soil...

  9. [Dynamics of microbial biomass carbon and nitrogen during foliar litter decomposition under artificial forest gap in Pinus massoniana plantation.

    Science.gov (United States)

    Zhang, Ming Jin; Chen, Liang Hua; Zhang, Jian; Yang, Wan Qin; Liu, Hua; Li, Xun; Zhang, Yan

    2016-03-01

    Nowadays large areas of plantations have caused serious ecological problems such as soil degradation and biodiversity decline. Artificial tending thinning and construction of mixed forest are frequently used ways when we manage plantations. To understand the effect of this operation mode on nutrient cycle of plantation ecosystem, we detected the dynamics of microbial bio-mass carbon and nitrogen during foliar litter decomposition of Pinus massoniana and Toona ciliate in seven types of gap in different sizes (G 1 : 100 m 2 , G 2 : 225 m 2 , G 3 : 400 m 2 , G 4 : 625 m 2 , G 5 : 900 m 2 , G 6 : 1225 m 2 , G 7 : 1600 m 2 ) of 42-year-old P. massoniana plantations in a hilly area of the upper Yang-tze River. The results showed that small and medium-sized forest gaps(G 1 -G 5 ) were more advantageous for the increment of microbial biomass carbon and nitrogen in the process of foliar litter decomposition. Along with the foliar litter decomposition during the experiment (360 d), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) in P. massoniana foliar litter and MBN in T. ciliata foliar litter first increased and then decreased, and respectively reached the maxima 9.87, 0.22 and 0.80 g·kg -1 on the 180 th d. But the peak (44.40 g·kg -1 ) of MBC in T. ciliata foliar litter appeared on the 90 th d. Microbial biomass carbon and nitrogen in T. ciliate was significantly higher than that of P. massoniana during foliar litter decomposition. Microbial biomass carbon and nitrogen in foliar litter was not only significantly associated with average daily temperature and the water content of foliar litter, but also closely related to the change of the quality of litter. Therefore, in the thinning, forest gap size could be controlled in the range of from 100 to 900 m 2 to facilitate the increase of microbial biomass carbon and nitrogen in the process of foliar litter decomposition, accelerate the decomposition of foliar litter and improve soil fertility of plantations.

  10. Non-Destructive Lichen Biomass Estimation in Northwestern Alaska: A Comparison of Methods

    Science.gov (United States)

    Rosso, Abbey; Neitlich, Peter; Smith, Robert J.

    2014-01-01

    Terrestrial lichen biomass is an important indicator of forage availability for caribou in northern regions, and can indicate vegetation shifts due to climate change, air pollution or changes in vascular plant community structure. Techniques for estimating lichen biomass have traditionally required destructive harvesting that is painstaking and impractical, so we developed models to estimate biomass from relatively simple cover and height measurements. We measured cover and height of forage lichens (including single-taxon and multi-taxa “community” samples, n = 144) at 73 sites on the Seward Peninsula of northwestern Alaska, and harvested lichen biomass from the same plots. We assessed biomass-to-volume relationships using zero-intercept regressions, and compared differences among two non-destructive cover estimation methods (ocular vs. point count), among four landcover types in two ecoregions, and among single-taxon vs. multi-taxa samples. Additionally, we explored the feasibility of using lichen height (instead of volume) as a predictor of stand-level biomass. Although lichen taxa exhibited unique biomass and bulk density responses that varied significantly by growth form, we found that single-taxon sampling consistently under-estimated true biomass and was constrained by the need for taxonomic experts. We also found that the point count method provided little to no improvement over ocular methods, despite increased effort. Estimated biomass of lichen-dominated communities (mean lichen cover: 84.9±1.4%) using multi-taxa, ocular methods differed only nominally among landcover types within ecoregions (range: 822 to 1418 g m−2). Height alone was a poor predictor of lichen biomass and should always be weighted by cover abundance. We conclude that the multi-taxa (whole-community) approach, when paired with ocular estimates, is the most reasonable and practical method for estimating lichen biomass at landscape scales in northwest Alaska. PMID:25079228

  11. Non-destructive lichen biomass estimation in northwestern Alaska: a comparison of methods.

    Directory of Open Access Journals (Sweden)

    Abbey Rosso

    Full Text Available Terrestrial lichen biomass is an important indicator of forage availability for caribou in northern regions, and can indicate vegetation shifts due to climate change, air pollution or changes in vascular plant community structure. Techniques for estimating lichen biomass have traditionally required destructive harvesting that is painstaking and impractical, so we developed models to estimate biomass from relatively simple cover and height measurements. We measured cover and height of forage lichens (including single-taxon and multi-taxa "community" samples, n = 144 at 73 sites on the Seward Peninsula of northwestern Alaska, and harvested lichen biomass from the same plots. We assessed biomass-to-volume relationships using zero-intercept regressions, and compared differences among two non-destructive cover estimation methods (ocular vs. point count, among four landcover types in two ecoregions, and among single-taxon vs. multi-taxa samples. Additionally, we explored the feasibility of using lichen height (instead of volume as a predictor of stand-level biomass. Although lichen taxa exhibited unique biomass and bulk density responses that varied significantly by growth form, we found that single-taxon sampling consistently under-estimated true biomass and was constrained by the need for taxonomic experts. We also found that the point count method provided little to no improvement over ocular methods, despite increased effort. Estimated biomass of lichen-dominated communities (mean lichen cover: 84.9±1.4% using multi-taxa, ocular methods differed only nominally among landcover types within ecoregions (range: 822 to 1418 g m-2. Height alone was a poor predictor of lichen biomass and should always be weighted by cover abundance. We conclude that the multi-taxa (whole-community approach, when paired with ocular estimates, is the most reasonable and practical method for estimating lichen biomass at landscape scales in northwest Alaska.

  12. Non-destructive lichen biomass estimation in northwestern Alaska: a comparison of methods.

    Science.gov (United States)

    Rosso, Abbey; Neitlich, Peter; Smith, Robert J

    2014-01-01

    Terrestrial lichen biomass is an important indicator of forage availability for caribou in northern regions, and can indicate vegetation shifts due to climate change, air pollution or changes in vascular plant community structure. Techniques for estimating lichen biomass have traditionally required destructive harvesting that is painstaking and impractical, so we developed models to estimate biomass from relatively simple cover and height measurements. We measured cover and height of forage lichens (including single-taxon and multi-taxa "community" samples, n = 144) at 73 sites on the Seward Peninsula of northwestern Alaska, and harvested lichen biomass from the same plots. We assessed biomass-to-volume relationships using zero-intercept regressions, and compared differences among two non-destructive cover estimation methods (ocular vs. point count), among four landcover types in two ecoregions, and among single-taxon vs. multi-taxa samples. Additionally, we explored the feasibility of using lichen height (instead of volume) as a predictor of stand-level biomass. Although lichen taxa exhibited unique biomass and bulk density responses that varied significantly by growth form, we found that single-taxon sampling consistently under-estimated true biomass and was constrained by the need for taxonomic experts. We also found that the point count method provided little to no improvement over ocular methods, despite increased effort. Estimated biomass of lichen-dominated communities (mean lichen cover: 84.9±1.4%) using multi-taxa, ocular methods differed only nominally among landcover types within ecoregions (range: 822 to 1418 g m-2). Height alone was a poor predictor of lichen biomass and should always be weighted by cover abundance. We conclude that the multi-taxa (whole-community) approach, when paired with ocular estimates, is the most reasonable and practical method for estimating lichen biomass at landscape scales in northwest Alaska.

  13. Model Effects on GLAS-Based Regional Estimates of Forest Biomass and Carbon

    Science.gov (United States)

    Nelson, Ross F.

    2010-01-01

    Ice, Cloud, and land Elevation Satellite (ICESat) / Geosciences Laser Altimeter System (GLAS) waveform data are used to estimate biomass and carbon on a 1.27 X 10(exp 6) square km study area in the Province of Quebec, Canada, below the tree line. The same input datasets and sampling design are used in conjunction with four different predictive models to estimate total aboveground dry forest biomass and forest carbon. The four models include non-stratified and stratified versions of a multiple linear model where either biomass or (biomass)(exp 0.5) serves as the dependent variable. The use of different models in Quebec introduces differences in Provincial dry biomass estimates of up to 0.35 G, with a range of 4.94 +/- 0.28 Gt to 5.29 +/-0.36 Gt. The differences among model estimates are statistically non-significant, however, and the results demonstrate the degree to which carbon estimates vary strictly as a function of the model used to estimate regional biomass. Results also indicate that GLAS measurements become problematic with respect to height and biomass retrievals in the boreal forest when biomass values fall below 20 t/ha and when GLAS 75th percentile heights fall below 7 m.

  14. Mapping and estimating the total living biomass and carbon in low-biomass woodlands using Landsat 8 CDR data

    Directory of Open Access Journals (Sweden)

    Belachew Gizachew

    2016-06-01

    Full Text Available Abstract Background A functional forest carbon measuring, reporting and verification (MRV system to support climate change mitigation policies, such as REDD+, requires estimates of forest biomass carbon, as an input to estimate emissions. A combination of field inventory and remote sensing is expected to provide those data. By linking Landsat 8 and forest inventory data, we (1 developed linear mixed effects models for total living biomass (TLB estimation as a function of spectral variables, (2 developed a 30 m resolution map of the total living carbon (TLC, and (3 estimated the total TLB stock of the study area. Inventory data consisted of tree measurements from 500 plots in 63 clusters in a 15,700 km2 study area, in miombo woodlands of Tanzania. The Landsat 8 data comprised two climate data record images covering the inventory area. Results We found a linear relationship between TLB and Landsat 8 derived spectral variables, and there was no clear evidence of spectral data saturation at higher biomass values. The root-mean-square error of the values predicted by the linear model linking the TLB and the normalized difference vegetation index (NDVI is equal to 44 t/ha (49 % of the mean value. The estimated TLB for the study area was 140 Mt, with a mean TLB density of 81 t/ha, and a 95 % confidence interval of 74–88 t/ha. We mapped the distribution of TLC of the study area using the TLB model, where TLC was estimated at 47 % of TLB. Conclusion The low biomass in the miombo woodlands, and the absence of a spectral data saturation problem suggested that Landsat 8 derived NDVI is suitable auxiliary information for carbon monitoring in the context of REDD+, for low-biomass, open-canopy woodlands.

  15. Microbial Community Activity And Plant Biomass Are Insensitive To Passive Warming In A Semiarid Ecosystem

    Science.gov (United States)

    Espinosa, N. J.; Fehmi, J. S.; Rasmussen, C.; Gallery, R. E.

    2017-12-01

    Soil microorganisms drive biogeochemical and nutrient cycling through the production of extracellular enzymes that facilitate organic matter decomposition and the flux of large amounts of carbon dioxide to the atmosphere. Although dryland ecosystems occupy over 40% of land cover and are projected to expand due to climate change, much of our current understanding of these processes comes from mesic temperate ecosystems. Understanding the responses of these globally predominant dryland ecosystems is therefore important yet complicated by co-occurring environmental changes. For example, the widespread and pervasive transition from grass to woody dominated landscapes is changing the hydrology, fire regimes, and carbon storage potential of semiarid ecosystems. In this study, we used a novel passive method of warming to conduct a warming experiment with added plant debris as either woodchip or biochar, to simulate different long-term carbon additions that accompany woody plant encroachment in semiarid ecosystems. The response of heterotrophic respiration, plant biomass, and microbial activity was monitored bi-annually. We hypothesized that the temperature manipulations would have direct and indirect effects on microbial activity. Warmer soils directly reduce the activity of soil extracellular enzymes through denaturation and dehydration of soil pores and indirectly through reducing microbe-available substrates and plant inputs. Overall, reduction in extracellular enzyme activity may reduce decomposition of coarse woody debris and potentially enhance soil carbon storage in semiarid ecosystems. For all seven hydrolytic enzymes examined as well as heterotrophic respiration, there was no consistent or significant response to experimental warming, regardless of seasonal climatic and soil moisture variation. The enzyme results observed here are consistent with the few other experimental results for warming in semiarid ecosystems and indicate that the controls over soil

  16. Method for calculating the variance and prediction intervals for biomass estimates obtained from allometric equations

    CSIR Research Space (South Africa)

    Kirton, A

    2010-08-01

    Full Text Available for calculating the variance and prediction intervals for biomass estimates obtained from allometric equations A KIRTON B SCHOLES S ARCHIBALD CSIR Ecosystem Processes and Dynamics, Natural Resources and the Environment P.O. BOX 395, Pretoria, 0001, South... intervals (confidence intervals for predicted values) for allometric estimates can be obtained using an example of estimating tree biomass from stem diameter. It explains how to deal with relationships which are in the power function form - a common form...

  17. Estimates of grassland biomass and turnover time on the Tibetan Plateau

    Science.gov (United States)

    Xia, Jiangzhou; Ma, Minna; Liang, Tiangang; Wu, Chaoyang; Yang, Yuanhe; Zhang, Li; Zhang, Yangjian; Yuan, Wenping

    2018-01-01

    The grassland of the Tibetan Plateau forms a globally significant biome, which represents 6% of the world’s grasslands and 44% of China’s grasslands. However, large uncertainties remain concerning the vegetation carbon storage and turnover time in this biome. In this study, we quantified the pool size of both the aboveground and belowground biomass and turnover time of belowground biomass across the Tibetan Plateau by combining systematic measurements taken from a substantial number of surveys (i.e. 1689 sites for aboveground biomass, 174 sites for belowground biomass) with a machine learning technique (i.e. random forest, RF). Our study demonstrated that the RF model is effective tool for upscaling local biomass observations to the regional scale, and for producing continuous biomass estimates of the Tibetan Plateau. On average, the models estimated 46.57 Tg (1 Tg = 1012g) C of aboveground biomass and 363.71 Tg C of belowground biomass in the Tibetan grasslands covering an area of 1.32 × 106 km2. The turnover time of belowground biomass demonstrated large spatial heterogeneity, with a median turnover time of 4.25 years. Our results also demonstrated large differences in the biomass simulations among the major ecosystem models used for the Tibetan Plateau, largely because of inadequate model parameterization and validation. This study provides a spatially continuous measure of vegetation carbon storage and turnover time, and provides useful information for advancing ecosystem models and improving their performance.

  18. Colonization Habitat Controls Biomass, Composition, and Metabolic Activity of Attached Microbial Communities in the Columbia River Hyporheic Corridor

    Energy Technology Data Exchange (ETDEWEB)

    Stern, Noah; Ginder-Vogel, Matthew; Stegen, James C.; Arntzen, Evan; Kennedy, David W.; Larget, Bret R.; Roden, Eric E.; Kostka, Joel E.

    2017-06-09

    Hydrologic exchange plays a critical role in biogeochemical cycling within the hyporheic zone (the interface between river water and groundwater) of riverine ecosystems. Such exchange may set limits on the rates of microbial metabolism and impose deterministic selection on microbial communities that adapt to dynamically changing dissolved organic carbon (DOC) sources. This study examined the response of attached microbial communities (in situcolonized sand packs) from groundwater, hyporheic, and riverbed habitats within the Columbia River hyporheic corridor to “cross-feeding” with either groundwater, river water, or DOC-free artificial fluids. Our working hypothesis was that deterministic selection duringin situcolonization would dictate the response to cross-feeding, with communities displaying maximal biomass and respiration when supplied with their native fluid source. In contrast to expectations, the major observation was that the riverbed colonized sand had much higher biomass and respiratory activity, as well as a distinct community structure, compared with those of the hyporheic and groundwater colonized sands. 16S rRNA gene amplicon sequencing revealed a much higher proportion of certain heterotrophic taxa as well as significant numbers of eukaryotic algal chloroplasts in the riverbed colonized sand. Significant quantities of DOC were released from riverbed sediment and colonized sand, and separate experiments showed that the released DOC stimulated respiration in the groundwater and piezometer colonized sand. These results suggest that the accumulation and degradation of labile particulate organic carbon (POC) within the riverbed are likely to release DOC, which may enter the hyporheic corridor during hydrologic exchange, thereby stimulating microbial activity and imposing deterministic selective pressure on the microbial community composition.

    IMPORTANCEThe influence of river water

  19. Radiocesium storage in soil microbial biomass of undisturbed alpine meadow soils and its relation to 137Cs soil-plant transfer

    International Nuclear Information System (INIS)

    Stemmer, Michael; Hromatka, Angelika; Lettner, Herbert; Strebl, Friederike

    2005-01-01

    This study focuses on radiocesium storage in soil microbial biomass of undisturbed alpine meadow sites and its relation to the soil-to-plant transfer. Soil and plant samples were taken in August 1999 from an altitude transect (800-1600 m.a.s.l.) at Gastein valley, Austria. Soil samples were subdivided into 3-cm layers for analyses of total, K 2 SO 4 -extractable and microbially stored 137 Cs. Microbial biomass was measured by the fumigation extraction method, and fungal biomass was quantified using ergosterol as biomarker molecule. In general, the quantity of 137 Cs stored in the living soil microbial biomass was relatively small. At the high-altitude meadows, showing high amounts of fungal biomass, microbially stored 137 Cs amounted to 0.64 ± 0.14 kBq m -2 which corresponds to about 1.2-2.7% of the total 137 Cs soil inventory. At lower altitudes, microbial 137 Cs content was distinctly smaller and in most cases not measurable at all using the fumigation extraction method. However, a positive correlation between the observed soil-to-plant aggregated transfer factor, microbially stored 137 Cs and fungal biomass was found, which indicates a possible role of fungal biomass in the storage and turnover of 137 Cs in soils and in the 137 Cs uptake by plants

  20. Generation of Electricity and Analysis of Microbial Communities in Wheat Straw Biomass-Powered Microbial Fuel Cells

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Min, Booki; Huang, L.

    2009-01-01

    Electricity generation from wheat straw hydrolysate and the microbial ecology of electricity producing microbial communities developed in two chamber microbial fuel cells (MFCs) were investigated. Power density reached 123 mW/m2 with an initial hydrolysate concentration of 1000 mg-COD/L while...

  1. TREE STEM AND CANOPY BIOMASS ESTIMATES FROM TERRESTRIAL LASER SCANNING DATA

    Directory of Open Access Journals (Sweden)

    K. Olofsson

    2017-10-01

    Full Text Available In this study an automatic method for estimating both the tree stem and the tree canopy biomass is presented. The point cloud tree extraction techniques operate on TLS data and models the biomass using the estimated stem and canopy volume as independent variables. The regression model fit error is of the order of less than 5 kg, which gives a relative model error of about 5 % for the stem estimate and 10–15 % for the spruce and pine canopy biomass estimates. The canopy biomass estimate was improved by separating the models by tree species which indicates that the method is allometry dependent and that the regression models need to be recomputed for different areas with different climate and different vegetation.

  2. Biomass estimation as a function of vertical forest structure and forest height: potential and limitations for radar remote sensing

    OpenAIRE

    Torano Caicoya, Astor; Kugler, Florian; Papathanassiou, Kostas; Biber, Peter; Pretzsch, Hans

    2010-01-01

    One common method to estimate biomass is measuring forest height and applying allometric equations to get forest biomass. Conditions like changing forest density or changing forest structure bias the allometric relations or biomass estimation fails completely. Remote sensing systems like SAR or LIDAR allow to measure vertical structure of forests. In this paper it is investigated whether vertical structure is sensitive to biomass. For this purpose vertical biomass profiles were calculated usi...

  3. Respiration, microbial biomass and soil phosphatase activity in two agroecosystems and one forest in Turrialba, Costa Rica

    Directory of Open Access Journals (Sweden)

    Wuellins Durango

    2015-06-01

    Full Text Available In order to evaluate some microbiological and biochemical characteristics, a comparative study was carried out, as related to 3 different land uses in Ultisols located in Grano de Oro, Turrialba, Costa Rica. Three soil management systems were selected (two agroecosystems, coffee and coffee-banana and forest. In each farm, 4 composite soil samples were collected, on which microbial biomass and respiration, and phosphatase enzyme activity analysis were performed. The microbial biomass in forest was statistically higher (423 mg C kg-1 compared to those in agroecosystems coffee and coffee-banana (77 and 111 mg C kg-1 respectively. Microbial respiration did not show differences due to land management (580, 560 and 570 μg CO2 g-1.day-1 in coffee, coffee-banana and forest systems, respectively. It was also determined that the enzyme phosphatase activity in forest soils was statistically higher (4432 μg p-NP g-1.h-1. The data suggest that soil conditions in the forest favor greater microbial activity and phosphatase biomass, as compared to agricultural systems.

  4. A comparison of selected parametric and non-parametric imputation methods for estimating forest biomass and basal area

    Science.gov (United States)

    Donald Gagliasso; Susan Hummel; Hailemariam. Temesgen

    2014-01-01

    Various methods have been used to estimate the amount of above ground forest biomass across landscapes and to create biomass maps for specific stands or pixels across ownership or project areas. Without an accurate estimation method, land managers might end up with incorrect biomass estimate maps, which could lead them to make poorer decisions in their future...

  5. Soil microbial species loss affects plant biomass and survival of an introduced bacterial strain, but not inducible plant defences.

    Science.gov (United States)

    Kurm, Viola; van der Putten, Wim H; Pineda, Ana; Hol, W H Gera

    2018-02-12

    Plant growth-promoting rhizobacteria (PGPR) strains can influence plant-insect interactions. However, little is known about the effect of changes in the soil bacterial community in general and especially the loss of rare soil microbes on these interactions. Here, the influence of rare soil microbe reduction on induced systemic resistance (ISR) in a wild ecotype of Arabidopsis thaliana against the aphid Myzus persicae was investigated. To create a gradient of microbial abundances, soil was inoculated with a serial dilution of a microbial community and responses of Arabidopsis plants that originated from the same site as the soil microbes were tested. Plant biomass, transcription of genes involved in plant defences, and insect performance were measured. In addition, the effects of the PGPR strain Pseudomonas fluorescens SS101 on plant and insect performance were tested under the influence of the various soil dilution treatments. Plant biomass showed a hump-shaped relationship with soil microbial community dilution, independent of aphid or Pseudomonas treatments. Both aphid infestation and inoculation with Pseudomonas reduced plant biomass, and led to downregulation of PR1 (salicylic acid-responsive gene) and CYP79B3 (involved in synthesis of glucosinolates). Aphid performance and gene transcription were unaffected by soil dilution. Neither the loss of rare microbial species, as caused by soil dilution, nor Pseudomonas affect the resistance of A. thaliana against M. persicae. However, both Pseudomonas survival and plant biomass respond to rare species loss. Thus, loss of rare soil microbial species can have a significant impact on both above- and below-ground organisms. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Is biomass a reliable estimate of plant fitness?

    Czech Academy of Sciences Publication Activity Database

    Younginger, B.S.; Sirová, Dagmara; Cruzan, M.B.; Ballhorn, D.J.

    2017-01-01

    Roč. 5, č. 2 (2017), č. článku 1600094. ISSN 2168-0450 Institutional support: RVO:60077344 Keywords : biomass * fecundity * fitness * plant performance * selection Subject RIV: EH - Ecology, Behaviour OBOR OECD: Plant sciences, botany Impact factor: 1.492, year: 2016

  7. Estimation and mapping of above ground biomass and carbon of ...

    African Journals Online (AJOL)

    In addition, field data from 35 sample plots comprising of the Diameter at Breast Height (DBH), co-ordinates of centroids and angles to the top and bottom of the individual trees was used for the analysis. The relationship between biomass and radar backscatter for selected sample plots was established using pairwise ...

  8. Fusion of Plant Height and Vegetation Indices for the Estimation of Barley Biomass

    Directory of Open Access Journals (Sweden)

    Nora Tilly

    2015-09-01

    Full Text Available Plant biomass is an important parameter for crop management and yield estimation. However, since biomass cannot be determined non-destructively, other plant parameters are used for estimations. In this study, plant height and hyperspectral data were used for barley biomass estimations with bivariate and multivariate models. During three consecutive growing seasons a terrestrial laser scanner was used to establish crop surface models for a pixel-wise calculation of plant height and manual measurements of plant height confirmed the results (R2 up to 0.98. Hyperspectral reflectance measurements were conducted with a field spectrometer and used for calculating six vegetation indices (VIs, which have been found to be related to biomass and LAI: GnyLi, NDVI, NRI, RDVI, REIP, and RGBVI. Furthermore, biomass samples were destructively taken on almost the same dates. Linear and exponential biomass regression models (BRMs were established for evaluating plant height and VIs as estimators of fresh and dry biomass. Each BRM was established for the whole observed period and pre-anthesis, which is important for management decisions. Bivariate BRMs supported plant height as a strong estimator (R2 up to 0.85, whereas BRMs based on individual VIs showed varying performances (R2: 0.07–0.87. Fused approaches, where plant height and one VI were used for establishing multivariate BRMs, yielded improvements in some cases (R2 up to 0.89. Overall, this study reveals the potential of remotely-sensed plant parameters for estimations of barley biomass. Moreover, it is a first step towards the fusion of 3D spatial and spectral measurements for improving non-destructive biomass estimations.

  9. Application of microbial biomass and activity measures to assess in situ bioremediation of chlorinated solvents

    International Nuclear Information System (INIS)

    Phelps, T.J.; Herbes, S.E.; Palumbo, A.V.; Pfiffner, S.M.; Mackowski, R.; Ringelberg, D.; White, D.C.; Tennessee Univ., Knoxville, TN

    1993-01-01

    Evaluating the effectiveness of chlorinated solvent remediation in the subsurface can be a significant problem given uncertainties in estimating the total mass of contaminants present. If the remediation technique is a biological activity, information on the progress and success of the remediation may be gained by monitoring changes in the mass and activities of microbial populations. The in situ bioremediation demonstration at the US Department of Energy (DOE) Savannah River Site (SRS) is designed to test the effectiveness of methane injection for the stimulation of in sediments. Past studies have shown the potential for degradation by native microbial populations. The design and implementation of the SRS Integrated Demonstration is described in this volume. A control phase without treatment was followed by a phase withdrawing air. The next phase included vacuum extraction plus air injection into the lower horizontal well located below the water table. The next period included the injection of 1% methane in air followed by injection of 4% methane in air. Based on the literature, it was hypothesized that the injection of methane would stimulate methanotrophic populations and thus accelerate biological degradation of TCE. Measuring the success of bioremediation is a complex effort that includes monitoring of changes in microbial populations associated with TCE degradation. These monitoring efforts are described in this paper and in related papers in this volume

  10. CMS: Estimated Deforested Area Biomass, Tropical America, Africa, and Asia, 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides estimates of pre-deforestation aboveground live woody biomass (AGLB) at 30-m resolution for deforested areas of tropical America, tropical...

  11. Estimation of optimal biomass fraction measuring cycle formunicipal solid waste incineration facilities in Korea.

    Science.gov (United States)

    Kang, Seongmin; Cha, Jae Hyung; Hong, Yoon-Jung; Lee, Daekyeom; Kim, Ki-Hyun; Jeon, Eui-Chan

    2018-01-01

    This study estimates the optimum sampling cycle using a statistical method for biomass fraction. More than ten samples were collected from each of the three municipal solid waste (MSW) facilities between June 2013 and March 2015 and the biomass fraction was analyzed. The analysis data were grouped into monthly, quarterly, semi-annual, and annual intervals and the optimum sampling cycle for the detection of the biomass fraction was estimated. Biomass fraction data did not show a normal distribution. Therefore, the non-parametric Kruskal-Wallis test was applied to compare the average values for each sample group. The Kruskal-Wallis test results showed that the average monthly, quarterly, semi-annual, and annual values for all three MSW incineration facilities were equal. Therefore, the biomass fraction at the MSW incineration facilities should be calculated on a yearly cycle which is the longest period of the temporal cycles tested. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Root carbon decomposition and microbial biomass response at different soil depths

    Science.gov (United States)

    Rumpel, C.

    2012-12-01

    The relationship between root litter addition and soil organic matter (SOM) formation in top- versus subsoils is unknown. The aim of this study was to investigate root litter decomposition and stabilisation in relation to microbial parameters in different soil depths. Our conceptual approach included incubation of 13C-labelled wheat roots at 30, 60 and 90 cm soil depth for 36 months under field conditions. Quantitative root carbon contribution to SOM was assessed, changes of bulk root chemistry studied by solid-state 13C NMR spectroscopy and lignin content and composition was assessed after CuO oxidation. Compound-specific isotope analysis allowed to assess the role of root lignin for soil C storage in the different soil depths. Microbial biomass and community structure was determined after DNA extraction. After three years of incubation, O-alkyl C most likely assigned to polysaccharides decreased in all soil depth compared to the initial root material. The degree of root litter decomposition assessed by the alkyl/O-alkyl ratio decreased with increasing soil depth, while aryl/O-alkyl ratio was highest at 60 cm depth. Root-derived lignin showed depth specific concentrations (30 fungi contribution increased after root litter addition. Their community structure changed after root litter addition and showed horizon specific dynamics. Our study shows that root litter addition can contribute to C storage in subsoils but did not influence C storage in topsoil. We conclude that specific conditions of single soil horizons have to be taken into account if root C dynamics are to be fully understood.

  13. Biomass

    Science.gov (United States)

    Bernard R. Parresol

    2001-01-01

    Biomass, the contraction for biological mass, is the amount of living material provided by a given area or volume of the earth's surface, whether terrestrial or aquatic. Biomass is important for commercial uses (e.g., fuel and fiber) and for national development planning, as well as for scientific studies of ecosystem productivity, energy and nutrient flows, and...

  14. Model Effects on GLAS-Based Regional Estimates of Forest Biomass and Carbon

    Science.gov (United States)

    Nelson, Ross

    2008-01-01

    ICESat/GLAS waveform data are used to estimate biomass and carbon on a 1.27 million sq km study area. the Province of Quebec, Canada, below treeline. The same input data sets and sampling design are used in conjunction with four different predictive models to estimate total aboveground dry forest biomass and forest carbon. The four models include nonstratified and stratified versions of a multiple linear model where either biomass or (square root of) biomass serves as the dependent variable. The use of different models in Quebec introduces differences in Provincial biomass estimates of up to 0.35 Gt (range 4.942+/-0.28 Gt to 5.29+/-0.36 Gt). The results suggest that if different predictive models are used to estimate regional carbon stocks in different epochs, e.g., y2005, y2015, one might mistakenly infer an apparent aboveground carbon "change" of, in this case, 0.18 Gt, or approximately 7% of the aboveground carbon in Quebec, due solely to the use of different predictive models. These findings argue for model consistency in future, LiDAR-based carbon monitoring programs. Regional biomass estimates from the four GLAS models are compared to ground estimates derived from an extensive network of 16,814 ground plots located in southern Quebec. Stratified models proved to be more accurate and precise than either of the two nonstratified models tested.

  15. Estimating Terrestrial Wood Biomass from Observed Concentrations of Atmospheric Carbon Dioxide

    NARCIS (Netherlands)

    Schaefer, K. M.; Peters, W.; Carvalhais, N.; van der Werf, G.; Miller, J.

    2008-01-01

    We estimate terrestrial disequilibrium state and wood biomass from observed concentrations of atmospheric CO2 using the CarbonTracker system coupled to the SiBCASA biophysical model. Starting with a priori estimates of carbon flux from the land, ocean, and fossil fuels, CarbonTracker estimates net

  16. From a tree to a stand in Finnish boreal forests - biomass estimation and comparison of methods

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chunjiang

    2009-07-01

    There is an increasing need to compare the results obtained with different methods of estimation of tree biomass in order to reduce the uncertainty in the assessment of forest biomass carbon. In this study, tree biomass was investigated in a 30-year-old Scots pine (Pinus sylvestris) (Young-Stand) and a 130-year-old mixed Norway spruce (Picea abies)-Scots pine stand (Mature-Stand) located in southern Finland (61deg50' N, 24deg22' E). In particular, a comparison of the results of different estimation methods was conducted to assess the reliability and suitability of their applications. For the trees in Mature-Stand, annual stem biomass increment fluctuated following a sigmoid equation, and the fitting curves reached a maximum level (from about 1 kg yr-1 for understorey spruce to 7 kg yr-1 for dominant pine) when the trees were 100 years old). Tree biomass was estimated to be about 70 Mg ha-1 in Young-Stand and about 220 Mg ha-1 in Mature-Stand. In the region (58.00-62.13 degN, 14-34 degE, <= 300 m a.s.l.) surrounding the study stands, the tree biomass accumulation in Norway spruce and Scots pine stands followed a sigmoid equation with stand age, with a maximum of 230 Mg ha-1 at the age of 140 years. In Mature-Stand, lichen biomass on the trees was 1.63 Mg ha-1 with more than half of the biomass occurring on dead branches, and the standing crop of litter lichen on the ground was about 0.09 Mg ha-1. There were substantial differences among the results estimated by different methods in the stands. These results imply that a possible estimation error should be taken into account when calculating tree biomass in a stand with an indirect approach. (orig.)

  17. The Impact of Extreme Weather Events on Dissolved Organic Matter and Microbial Biomass of chernozem soils

    Science.gov (United States)

    Müller, Ann-Christin; Blagodatskaya, Evgenia

    2017-04-01

    The aim of this experiment was to study the impact of the extreme weather events freezing-thawing and drying-rewetting on C-, N- and P-dynamics in dissolved organic matter and microbial biomass. The three variants of a chernozem soil (Voronezh region, Russia) are (1) fertilized maize cropping, (2) unfertilized maize cropping and (3) a bare fallow. After both abiotic perturbations the respiration rates were generally lower in the freezing-thawing than in the drying-rewetting treatment, due to the lower temperature. The elevated respiration came along with the decay of organic matter, which was also manifested in increased mineralization of C, N and P immediately after rewetting. However, freezing-thawing had significantly less impact on C-, N- and P-mobilization. We conclude that drying-rewetting leads to an initially increased mobilization of C, N and P, which becomes obvious as increased amounts of DOM immediately after rewetting. Freezing-thawing does not affect mobilization in the same way. There, only an increased mobilization of C can be observed. Especially concerning N and P, the reaction is dependent on the form of use/cropping in both treatments.

  18. [Study on soil enzyme activities and microbial biomass carbon in greenland irrigated with reclaimed water].

    Science.gov (United States)

    Pan, Neng; Hou, Zhen-An; Chen, Wei-Ping; Jiao, Wen-Tao; Peng, Chi; Liu, Wen

    2012-12-01

    The physicochemical properties of soils might be changed under the long-term reclaimed water irrigation. Its effects on soil biological activities have received great attentions. We collected surface soil samples from urban green spaces and suburban farmlands of Beijing. Soil microbial biomass carbon (SMBC), five types of soil enzyme activities (urease, alkaline phosphatase, invertase, dehydrogenase and catalase) and physicochemical indicators in soils were measured subsequently. SMBC and enzyme activities from green land soils irrigated with reclaimed water were higher than that of control treatments using drinking water, but the difference is not significant in farmland. The SMBC increased by 60.1% and 14.2% than those control treatments in 0-20 cm soil layer of green land and farmland, respectively. Compared with their respective controls, the activities of enzymes in 0-20 cm soil layer of green land and farmland were enhanced by an average of 36.7% and 7.4%, respectively. Investigation of SMBC and enzyme activities decreased with increasing of soil depth. Significantly difference was found between 0-10 cm and 10-20 cm soil layer in green land. Soil biological activities were improved with long-term reclaimed water irrigation in Beijing.

  19. Ecological Insights into the Dynamics of Plant Biomass-Degrading Microbial Consortia.

    Science.gov (United States)

    Jiménez, Diego Javier; Dini-Andreote, Francisco; DeAngelis, Kristen M; Singer, Steven W; Salles, Joana Falcão; van Elsas, Jan Dirk

    2017-10-01

    Plant biomass (PB) is an important resource for biofuel production. However, the frequent lack of efficiency of PB saccharification is still an industrial bottleneck. The use of enzyme cocktails produced from PB-degrading microbial consortia (PB-dmc) is a promising approach to optimize this process. Nevertheless, the proper use and manipulation of PB-dmc depends on a sound understanding of the ecological processes and mechanisms that exist in these communities. This Opinion article provides an overview of arguments as to how spatiotemporal nutritional fluxes influence the successional dynamics and ecological interactions (synergism versus competition) between populations in PB-dmc. The themes of niche occupancy, 'sugar cheaters', minimal effective consortium, and the Black Queen Hypothesis are raised as key subjects that foster our appraisal of such systems. Here we provide a conceptual framework that describes the critical topics underpinning the ecological basis of PB-dmc, giving a solid foundation upon which further prospective experimentation can be developed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Grasslands and Croplands Have Different Microbial Biomass Carbon Levels per Unit of Soil Organic Carbon

    Directory of Open Access Journals (Sweden)

    Terence P. McGonigle

    2017-07-01

    Full Text Available Primarily using cropped systems, previous studies have reported a positive linear relationship between microbial biomass carbon (MBC and soil organic carbon (SOC. We conducted a meta-analysis to explore this relationship separately for grasslands and croplands using available literature. Studies were limited to those using fumigation–extraction for MBC for field samples. Trials were noted separately where records were distinct in space or time. Grasslands were naturally occurring, restored, or seeded. Cropping systems were typical of the temperate zone. MBC had a positive linear response to increasing SOC that was significant in both grasslands (p < 0.001; r2 = 0.76 and croplands (p < 0.001; r2 = 0.48. However, MBC increased 2.5-fold more steeply per unit of increasing SOC for grassland soils, as compared to the corresponding response in cropland soils. Expressing MBC as a proportion of SOC across the regression overall, slopes corresponded to 2.7% for grasslands and 1.1% for croplands. The slope of the linear relationship for grasslands was significantly (p = 0.0013 steeper than for croplands. The difference between the two systems is possibly caused by a greater proportion of SOC in grasslands being active rather than passive, relative to that in croplands, with that active fraction promoting the formation of MBC.

  1. Allometric equations for estimating standing biomass of Avicennia marina in Bushehr of Iran

    Directory of Open Access Journals (Sweden)

    Akbar Ghasemi

    2016-07-01

    Full Text Available Today, it is important to use of ecological indicators, such as biomass for recognizing the special status of ecosystems, such as mangrove forests and also monitoring and evaluating changes through a specific period. Because using the direct method of evaluating biomass would be destructive, it is common in all similar area to use determine exact Allometric equations by using the statistical relationship between the structural characteristics of trees and their biomass and use these equations to estimate the biomass of trees. The aim of this study is estimate the aboveground biomass of mangroves and determine Allometric models for Nayband area in Bushehr, located in southern Iran. A number of mangrove trees were randomly selected. Collar diameter, crown diameter and tree height of standing trees were measured. After logging and weighing fresh weight, dry weight, trunk and branches were obtained in laboratory and biomass of components was calculated. The relationship between quantities feature of trees and biomass for determination of allometric equation was studied by using linear, power and exponential regression. The equations were compared with each other based on the different modeling parameters. The highest significant correlation was found between crown diameters and dry weight (R > 0.90. The best equations were obtained by means of an exponential and power regression models (R2adj> 0.90. The models were obtained from explained factor, suggests that there might be a relationship between the characteristics of mangrove trees and biomass.

  2. The desorption of Phosphorous (32 P) fixed on iron and aluminum oxy-hydroxide surfaces by the soil microbial biomass

    International Nuclear Information System (INIS)

    Araujo, Lilian Maria Cesar de.

    1995-02-01

    This work determines whether the soil microbial biomass, with an ample supply of available C, can utilize P adsorber in the surfaces of oxy-hydroxides of Fe or Al of soil-P deficient soils. To simulate the surfaces of the natural Fe and Al compounds, synthetic oxy-hydroxides of Fe and Al, impregnated in strips of filter paper, and containing P tagged with 32 P, were used. (author). 60 refs., 7 figs., 7 tabs

  3. Genome-centric metatranscriptomes and ecological roles of the active microbial populations during cellulosic biomass anaerobic digestion.

    Science.gov (United States)

    Jia, Yangyang; Ng, Siu-Kin; Lu, Hongyuan; Cai, Mingwei; Lee, Patrick K H

    2018-01-01

    Although anaerobic digestion for biogas production is used worldwide in treatment processes to recover energy from carbon-rich waste such as cellulosic biomass, the activities and interactions among the microbial populations that perform anaerobic digestion deserve further investigations, especially at the population genome level. To understand the cellulosic biomass-degrading potentials in two full-scale digesters, this study examined five methanogenic enrichment cultures derived from the digesters that anaerobically digested cellulose or xylan for more than 2 years under 35 or 55 °C conditions. Metagenomics and metatranscriptomics were used to capture the active microbial populations in each enrichment culture and reconstruct their meta-metabolic network and ecological roles. 107 population genomes were reconstructed from the five enrichment cultures using a differential coverage binning approach, of which only a subset was highly transcribed in the metatranscriptomes. Phylogenetic and functional convergence of communities by enrichment condition and phase of fermentation was observed for the highly transcribed populations in the metatranscriptomes. In the 35 °C cultures grown on cellulose, Clostridium cellulolyticum -related and Ruminococcus -related bacteria were identified as major hydrolyzers and primary fermenters in the early growth phase, while Clostridium leptum -related bacteria were major secondary fermenters and potential fatty acid scavengers in the late growth phase. While the meta-metabolism and trophic roles of the cultures were similar, the bacterial populations performing each function were distinct between the enrichment conditions. Overall, a population genome-centric view of the meta-metabolism and functional roles of key active players in anaerobic digestion of cellulosic biomass was obtained. This study represents a major step forward towards understanding the microbial functions and interactions at population genome level during the

  4. Abrolhos bank reef health evaluated by means of water quality, microbial diversity, benthic cover, and fish biomass data.

    Directory of Open Access Journals (Sweden)

    Thiago Bruce

    Full Text Available The health of the coral reefs of the Abrolhos Bank (Southwestern Atlantic was characterized with a holistic approach using measurements of four ecosystem components: (i inorganic and organic nutrient concentrations, [1] fish biomass, [1] macroalgal and coral cover and (iv microbial community composition and abundance. The possible benefits of protection from fishing were particularly evaluated by comparing sites with varying levels of protection. Two reefs within the well-enforced no-take area of the National Marine Park of Abrolhos (Parcel dos Abrolhos and California were compared with two unprotected coastal reefs (Sebastião Gomes and Pedra de Leste and one legally protected but poorly enforced coastal reef (the "paper park" of Timbebas Reef. The fish biomass was lower and the fleshy macroalgal cover was higher in the unprotected reefs compared with the protected areas. The unprotected and protected reefs had similar seawater chemistry. Lower vibrio CFU counts were observed in the fully protected area of California Reef. Metagenome analysis showed that the unprotected reefs had a higher abundance of archaeal and viral sequences and more bacterial pathogens, while the protected reefs had a higher abundance of genes related to photosynthesis. Similar to other reef systems in the world, there was evidence that reductions in the biomass of herbivorous fishes and the consequent increase in macroalgal cover in the Abrolhos Bank may be affecting microbial diversity and abundance. Through the integration of different types of ecological data, the present study showed that protection from fishing may lead to greater reef health. The data presented herein suggest that protected coral reefs have higher microbial diversity, with the most degraded reef (Sebastião Gomes showing a marked reduction in microbial species richness. It is concluded that ecological conditions in unprotected reefs may promote the growth and rapid evolution of opportunistic

  5. Black Nitrogen as a source for the built-up of microbial biomass in soils

    Science.gov (United States)

    López-Martín, María; Milter, Anja; Knicker, Heike

    2016-04-01

    In areas with frequent wildfires, soil organic nitrogen (SON) is sequestered in pyrogenic organic matter (PyOM) due to heat-induced transformation of proteinaceous compounds into N-heterocycles, i.e. pyrrole, imidazole and indole compounds. These newly formed structures, known as Black Nitrogen (BN), have been assumed to be hardly degradable by microorganisms, thus being efficiently sequestered from the N cycle. On the other hand, a previous study showed that nitrogen of BN can be used by plants for the built-up of their biomass (de la Rosa and Knicker 2011). Thus, BN may play an important role as an N source during the recovery of the forest after a fire event. In order to obtain a more profound understanding of the role of BN within the N cycle in soils, we studied the bioavailability and incorporation of N derived from PyOM into microbial amino acids. For that, pots with soil from a burnt and an unburnt Cambisol located under a Mediterranean forest were covered with different amendments. The toppings were mixtures of unlabeled KNO3 with 15N labeled grass or 15N-labeled PyOM from burned grass and K15NO3 mixed with unlabeled grass material or PyOM. The pots were kept in the greenhouse under controlled conditions for 16 months and were sampled after 0.5, 1, 5, 8 and 16 months. From all samples the amino acids were extracted after hydrolysis (6 M HCl, 22 h, 110 °C) and quantified via gas chromatography mass spectrometry (GC/MS). The fate of 15N was followed by isotopic ratio mass spectrometry (IRMS). The results show that the contribution of extractable amino acids to total soil organic matter was always higher in the unburnt than in the burnt soil. However, with ongoing incubation their amount decreased. Already after 0.5 months, some PyOM-derived 15N was incorporated into the extractable amino acids and the amount increased with experiment time. Since this can only occur after prior microbial degradation of PyOM our results clearly support a lower biochemical

  6. [Effects of adding straw carbon source to root knot nematode diseased soil on soil microbial biomass and protozoa abundance].

    Science.gov (United States)

    Zhang, Si-Hui; Lian, Jian-Hong; Cao, Zhi-Ping; Zhao, Li

    2013-06-01

    A field experiment with successive planting of tomato was conducted to study the effects of adding different amounts of winter wheat straw (2.08 g x kg(-1), 1N; 4.16 g x kg(-1), 2N; and 8.32 g x kg(-1), 4N) to the soil seriously suffered from root knot nematode disease on the soil microbial biomass and protozoa abundance. Adding straw carbon source had significant effects on the contents of soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) and the abundance of soil protozoa, which all decreased in the order of 4N > 2N > 1N > CK. The community structure of soil protozoa also changed significantly under straw addition. In the treatments with straw addition, the average proportion of fagellate, amoeba, and ciliates accounted for 36.0%, 59.5%, and 4.5% of the total protozoa, respectively. Under the same adding amounts of wheat straw, there was an increase in the soil MBC and MBN contents, MBC/MBN ratio, and protozoa abundance with increasing cultivation period.

  7. Estimating Biomass of Barley Using Crop Surface Models (CSMs Derived from UAV-Based RGB Imaging

    Directory of Open Access Journals (Sweden)

    Juliane Bendig

    2014-10-01

    Full Text Available Crop monitoring is important in precision agriculture. Estimating above-ground biomass helps to monitor crop vitality and to predict yield. In this study, we estimated fresh and dry biomass on a summer barley test site with 18 cultivars and two nitrogen (N-treatments using the plant height (PH from crop surface models (CSMs. The super-high resolution, multi-temporal (1 cm/pixel CSMs were derived from red, green, blue (RGB images captured from a small unmanned aerial vehicle (UAV. Comparison with PH reference measurements yielded an R2 of 0.92. The test site with different cultivars and treatments was monitored during “Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie” (BBCH Stages 24–89. A high correlation was found between PH from CSMs and fresh biomass (R2 = 0.81 and dry biomass (R2 = 0.82. Five models for above-ground fresh and dry biomass estimation were tested by cross-validation. Modelling biomass between different N-treatments for fresh biomass produced the best results (R2 = 0.71. The main limitation was the influence of lodging cultivars in the later growth stages, producing irregular plant heights. The method has potential for future application by non-professionals, i.e., farmers.

  8. Estimating and mapping ecological processes influencing microbial community assembly.

    Science.gov (United States)

    Stegen, James C; Lin, Xueju; Fredrickson, Jim K; Konopka, Allan E

    2015-01-01

    Ecological community assembly is governed by a combination of (i) selection resulting from among-taxa differences in performance; (ii) dispersal resulting from organismal movement; and (iii) ecological drift resulting from stochastic changes in population sizes. The relative importance and nature of these processes can vary across environments. Selection can be homogeneous or variable, and while dispersal is a rate, we conceptualize extreme dispersal rates as two categories; dispersal limitation results from limited exchange of organisms among communities, and homogenizing dispersal results from high levels of organism exchange. To estimate the influence and spatial variation of each process we extend a recently developed statistical framework, use a simulation model to evaluate the accuracy of the extended framework, and use the framework to examine subsurface microbial communities over two geologic formations. For each subsurface community we estimate the degree to which it is influenced by homogeneous selection, variable selection, dispersal limitation, and homogenizing dispersal. Our analyses revealed that the relative influences of these ecological processes vary substantially across communities even within a geologic formation. We further identify environmental and spatial features associated with each ecological process, which allowed mapping of spatial variation in ecological-process-influences. The resulting maps provide a new lens through which ecological systems can be understood; in the subsurface system investigated here they revealed that the influence of variable selection was associated with the rate at which redox conditions change with subsurface depth.

  9. Estimating and Mapping Ecological Processes Influencing Microbial Community Assembly

    Directory of Open Access Journals (Sweden)

    James C Stegen

    2015-05-01

    Full Text Available Ecological community assembly is governed by a combination of (i selection resulting from among-taxa differences in performance; (ii dispersal resulting from organismal movement; and (iii ecological drift resulting from stochastic changes in population sizes. The relative importance and nature of these processes can vary across environments. Selection can be homogeneous or variable, and while dispersal is a rate, we conceptualize extreme dispersal rates as two categories; dispersal limitation results from limited exchange of organisms among communities, and homogenizing dispersal results from high levels of organism exchange. To estimate the influence and spatial variation of each process we extend a recently developed statistical framework, use a simulation model to evaluate the accuracy of the extended framework, and use the framework to examine subsurface microbial communities over two geologic formations. For each subsurface community we estimate the degree to which it is influenced by homogeneous selection, variable selection, dispersal limitation, and homogenizing dispersal. Our analyses revealed that the relative influences of these ecological processes vary substantially across communities even within a geologic formation. We further identify environmental and spatial features associated with each ecological process, which allowed mapping of spatial variation in ecological-process-influences. The resulting maps provide a new lens through which ecological systems can be understood; in the subsurface system investigated here they revealed that the influence of variable selection was associated with the rate at which redox conditions change with subsurface depth.

  10. National scale biomass estimators for United States tree species

    Science.gov (United States)

    Jennifer C. Jenkins; David C. Chojnacky; Linda S. Heath; Richard A. Birdsey

    2003-01-01

    Estimates of national-scale forest carbon (C) stocks and fluxes are typically based on allometric regression equations developed using dimensional analysis techniques. However, the literature is inconsistent and incomplete with respect to large-scale forest C estimation. We compiled all available diameter-based allometric regression equations for estimating total...

  11. Seasonal and diel variability in dissolved DNA and in microbial biomass and activity in a subtropical estuary

    International Nuclear Information System (INIS)

    Paul, J.H.; Deflaun, M.F.; Jeffrey, W.H.; David, A.W.

    1988-01-01

    Dissolved DNA and microbial biomass and activity parameters were measured over a 15-month period at three stations along a salinity gradient in Tampa Bay, Fla. Dissolved DNA showed seasonal variation, with minimal values in December and January and maximal values in summer months (July and August). This pattern of seasonal variation followed that of particulate DNA and water temperature and did not correlate with bacterioplankton (direct counts and [ 3 H] thymidine incorporation) or phytoplankton (chlorophyll α and 14 CO 2 fixation) biomass and activity. Microautotrophic populations showed maxima in the spring and fall, whereas microheterotrophic activity was greatest in late summer (September). Both autotrophic and heterotrophic microbial activity was greatest at the high estuarine (low salinity) station and lowest at the mouth of the bay (high salinity station), irrespective of season. Dissolved DNA carbon and phosphorus constituted 0.11 +/- 0.05% of the dissolved organic carbon and 6.6 +/- 6.5% of the dissolved organic phosphorus, respectively. Strong diel periodicity was noted in dissolved DNA and in microbial activity in Bayboro Harbor during the dry season. A noon maximum in primary productivity was followed by an 8 p.m. maximum in heterotrophic activity and a midnight maximum in dissolved DNA. This diel periodicity was less pronounced in the wet season, when microbial parameters were strongly influenced by episodic inputs of freshwater

  12. Influence of soil management practices and substrate availability on microbial biomass and its activities in some haplic luvisols

    Energy Technology Data Exchange (ETDEWEB)

    Friedel, Jurgen K [University Hohenheeim, Stuttgart (Germany)

    1996-07-01

    Soil microbial biomass and activities are sensitive indicators of management effects. Higher contents of microbial biomass and higher activities, for example, are found with crop rotations in contrast to bare fallow and mono culture systems. The main reason for these differences is a higher input of crop and root residues in crop rotation systems, leading to more microbial available substrate. The objectives of this study were to describe indices for microbial available substrate in arable soils depending on management practices, and to relate them with soil microbial biomass and activities. At two locations (Muttergarten and hinger Hof near the University of Hohenheim, Stuttgart, SW-Germany), adenosine triphosphate (ATP) contents and microbial activities were measured in haplic Luviosls. As indices for microbial available substrate, water soluble organic carbon compounds in soils were determined and decomposable young soil organic matter was calculated from organic fertilizers and crop and root residues using empirical decomposition functions. Higher ATP contents and microbial activities were observed along with organic fertilization (liquid cattle manure) than with mineral fertilization. Shallow cultivation with a rotary cultivator led to higher values of microbial properties in the upper part of the Ap horizon than ploughing. Soil microbial parameters were higher in plots under a rape-cereals crop rotation, compared to a legumes-cereals crop rotation. Microbial biomass and its activities were related more closely to decomposable young soil organic matter than to soil humus content or to any other soil property. Water soluble organic carbon compounds did not prove as an indicator of microbial available substrate. [Spanish] La biomasa y la actividad microbianas son indicadores sensibles de los efectos del manejo del suelo. Por ejemplo, con la rotacion de cultivos se obtiene un contenido y una actividad mayores de la biomasa microbiana en contraste con el simple

  13. Seasonal variations and effects of nutrient applications on N and P and microbial biomass under two temperate heathland plants

    DEFF Research Database (Denmark)

    Nielsen, Pia Lund; Andresen, Louise Christoffersen; Michelsen, Anders

    2009-01-01

    . The microbial biomass on the other hand was positively related to soil water content in fertilized plots indicating that this was due to an indirect effect of enhanced nutrient availability. Microbial N and P pools were respectively 1000 and 100 times higher than the pool of inorganic N and P, and microbes...... this process. In this study the soil properties under two dominant heathland plants, the dwarf shrub Calluna vulgaris and the grass Deschampsia flexuosa, were investigated, with focus on nutrient content in the organic top soil and soil microbes during the main growing season and effects of nutrient amendments...... therefore may play an important role in regulating plant nutrient supply. Judged from responses of inorganic and microbial N and P concentrations to added N and P, N seemed to limit C. vulgaris and soil microbes below while P seemed to limit D. flexuosa and soil microbes below this species. There were lower...

  14. The utilization of false color aerial photography for macrophyte biomass estimation in the Oosterschelde (the Netherlands)

    Science.gov (United States)

    Meulstee, C.; Vanstokkom, H.

    1985-01-01

    The correlation between the biomass of sea grass and seaweed samples in a sidebranch of the Oosterschelde delta (Netherlands) and density ratios of this area on color infrared aerial photographs was investigated. As the Oosterschelde will become more divided from the North Sea after pier dam completion, an increase of macrophytes is expected. In an area where the weeds Ulva, Cheatomorpha, Entermorpha, Cladophora, Fucus vesuculosis, and the grasses Zostera noltii and Zostera marina are found, 53 biomass samples of a 0.054 sq m surface each were collected. The relation between covering degree and biomass was estimated. Using a transmission-densitometer adjusted to 3 to 1 mm, densities on 1:10,000 and 1:20,000 scale photographs were measured. A gage line was determined in a density-biomass diagram. The method is shown to be useful for an efficient, accurate biomass determination in the Oosterschelde.

  15. Microbial biomass and biological activity of soils and soil-like bodies in coastal oases of Antarctica

    Science.gov (United States)

    Nikitin, D. A.; Marfenina, O. E.; Kudinova, A. G.; Lysak, L. V.; Mergelov, N. S.; Dolgikh, A. V.; Lupachev, A. V.

    2017-09-01

    The method of luminescent microscopy has been applied to study the structure of the microbial biomass of soils and soil-like bodies in East (the Thala Hills and Larsemann Hills oases) and West (Cape Burks, Hobbs coast) Antarctica. According to Soil Taxonomy, the studied soils mainly belong to the subgroups of Aquic Haploturbels, Typic Haploturbels, Typic Haplorthels, and Lithic Haplorthels. The major contribution to their microbial biomass belongs to fungi. The highest fungal biomass (up to 790 μg C/g soil) has been found in the soils with surface organic horizons in the form of thin moss/lichen litters, in which the development of fungal mycelium is most active. A larger part of fungal biomass (70-98%) is represented by spores. For the soils without vegetation cover, the accumulation of bacterial and fungal biomass takes place in the horizons under surface desert pavements. In the upper parts of the soils without vegetation cover and in the organic soil horizons, the major part (>60%) of fungal mycelium contains protective melanin pigments. Among bacteria, the high portion (up to 50%) of small filtering forms is observed. A considerable increase (up to 290.2 ± 27 μg C/g soil) in the fungal biomass owing to the development of yeasts has been shown for gley soils (gleyzems) developing from sapropel sediments under subaquatic conditions and for the algal-bacterial mat on the bottom of the lake (920.7 ± 46 μg C/g soil). The production of carbon dioxide by the soils varies from 0.47 to 2.34 μg C-CO2/(g day). The intensity of nitrogen fixation in the studied samples is generally low: from 0.08 to 55.85 ng C2H4/(g day). The intensity of denitrification varies from 0.09 to 19.28 μg N-N2O/(g day).

  16. Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam.

    Science.gov (United States)

    Nam, Vu Thanh; van Kuijk, Marijke; Anten, Niels P R

    2016-01-01

    Allometric regression models are widely used to estimate tropical forest biomass, but balancing model accuracy with efficiency of implementation remains a major challenge. In addition, while numerous models exist for aboveground mass, very few exist for roots. We developed allometric equations for aboveground biomass (AGB) and root biomass (RB) based on 300 (of 45 species) and 40 (of 25 species) sample trees respectively, in an evergreen forest in Vietnam. The biomass estimations from these local models were compared to regional and pan-tropical models. For AGB we also compared local models that distinguish functional types to an aggregated model, to assess the degree of specificity needed in local models. Besides diameter at breast height (DBH) and tree height (H), wood density (WD) was found to be an important parameter in AGB models. Existing pan-tropical models resulted in up to 27% higher estimates of AGB, and overestimated RB by nearly 150%, indicating the greater accuracy of local models at the plot level. Our functional group aggregated local model which combined data for all species, was as accurate in estimating AGB as functional type specific models, indicating that a local aggregated model is the best choice for predicting plot level AGB in tropical forests. Finally our study presents the first allometric biomass models for aboveground and root biomass in forests in Vietnam.

  17. Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam.

    Directory of Open Access Journals (Sweden)

    Vu Thanh Nam

    Full Text Available Allometric regression models are widely used to estimate tropical forest biomass, but balancing model accuracy with efficiency of implementation remains a major challenge. In addition, while numerous models exist for aboveground mass, very few exist for roots. We developed allometric equations for aboveground biomass (AGB and root biomass (RB based on 300 (of 45 species and 40 (of 25 species sample trees respectively, in an evergreen forest in Vietnam. The biomass estimations from these local models were compared to regional and pan-tropical models. For AGB we also compared local models that distinguish functional types to an aggregated model, to assess the degree of specificity needed in local models. Besides diameter at breast height (DBH and tree height (H, wood density (WD was found to be an important parameter in AGB models. Existing pan-tropical models resulted in up to 27% higher estimates of AGB, and overestimated RB by nearly 150%, indicating the greater accuracy of local models at the plot level. Our functional group aggregated local model which combined data for all species, was as accurate in estimating AGB as functional type specific models, indicating that a local aggregated model is the best choice for predicting plot level AGB in tropical forests. Finally our study presents the first allometric biomass models for aboveground and root biomass in forests in Vietnam.

  18. Lidar aboveground vegetation biomass estimates in shrublands: Prediction, uncertainties and application to coarser scales

    Science.gov (United States)

    Li, Aihua; Dhakal, Shital; Glenn, Nancy F.; Spaete, Luke P.; Shinneman, Douglas; Pilliod, David S.; Arkle, Robert; McIlroy, Susan

    2017-01-01

    Our study objectives were to model the aboveground biomass in a xeric shrub-steppe landscape with airborne light detection and ranging (Lidar) and explore the uncertainty associated with the models we created. We incorporated vegetation vertical structure information obtained from Lidar with ground-measured biomass data, allowing us to scale shrub biomass from small field sites (1 m subplots and 1 ha plots) to a larger landscape. A series of airborne Lidar-derived vegetation metrics were trained and linked with the field-measured biomass in Random Forests (RF) regression models. A Stepwise Multiple Regression (SMR) model was also explored as a comparison. Our results demonstrated that the important predictors from Lidar-derived metrics had a strong correlation with field-measured biomass in the RF regression models with a pseudo R2 of 0.76 and RMSE of 125 g/m2 for shrub biomass and a pseudo R2 of 0.74 and RMSE of 141 g/m2 for total biomass, and a weak correlation with field-measured herbaceous biomass. The SMR results were similar but slightly better than RF, explaining 77–79% of the variance, with RMSE ranging from 120 to 129 g/m2 for shrub and total biomass, respectively. We further explored the computational efficiency and relative accuracies of using point cloud and raster Lidar metrics at different resolutions (1 m to 1 ha). Metrics derived from the Lidar point cloud processing led to improved biomass estimates at nearly all resolutions in comparison to raster-derived Lidar metrics. Only at 1 m were the results from the point cloud and raster products nearly equivalent. The best Lidar prediction models of biomass at the plot-level (1 ha) were achieved when Lidar metrics were derived from an average of fine resolution (1 m) metrics to minimize boundary effects and to smooth variability. Overall, both RF and SMR methods explained more than 74% of the variance in biomass, with the most important Lidar variables being associated with vegetation structure

  19. Assimilating satellite-based canopy height within an ecosystem model to estimate aboveground forest biomass

    Science.gov (United States)

    Joetzjer, E.; Pillet, M.; Ciais, P.; Barbier, N.; Chave, J.; Schlund, M.; Maignan, F.; Barichivich, J.; Luyssaert, S.; Hérault, B.; von Poncet, F.; Poulter, B.

    2017-07-01

    Despite advances in Earth observation and modeling, estimating tropical biomass remains a challenge. Recent work suggests that integrating satellite measurements of canopy height within ecosystem models is a promising approach to infer biomass. We tested the feasibility of this approach to retrieve aboveground biomass (AGB) at three tropical forest sites by assimilating remotely sensed canopy height derived from a texture analysis algorithm applied to the high-resolution Pleiades imager in the Organizing Carbon and Hydrology in Dynamic Ecosystems Canopy (ORCHIDEE-CAN) ecosystem model. While mean AGB could be estimated within 10% of AGB derived from census data in average across sites, canopy height derived from Pleiades product was spatially too smooth, thus unable to accurately resolve large height (and biomass) variations within the site considered. The error budget was evaluated in details, and systematic errors related to the ORCHIDEE-CAN structure contribute as a secondary source of error and could be overcome by using improved allometric equations.

  20. From a tree to a stand in Finnish boreal forests: biomass estimation and comparison of methods

    OpenAIRE

    Liu, Chunjiang

    2009-01-01

    There is an increasing need to compare the results obtained with different methods of estimation of tree biomass in order to reduce the uncertainty in the assessment of forest biomass carbon. In this study, tree biomass was investigated in a 30-year-old Scots pine (Pinus sylvestris) (Young-Stand) and a 130-year-old mixed Norway spruce (Picea abies)-Scots pine stand (Mature-Stand) located in southern Finland (61º50' N, 24º22' E). In particular, a comparison of the results of different estimati...

  1. Efficacy of generic allometric equations for estimating biomass: a test in Japanese natural forests.

    Science.gov (United States)

    Ishihara, Masae I; Utsugi, Hajime; Tanouchi, Hiroyuki; Aiba, Masahiro; Kurokawa, Hiroko; Onoda, Yusuke; Nagano, Masahiro; Umehara, Toru; Ando, Makoto; Miyata, Rie; Hiura, Tsutom

    2015-07-01

    Accurate estimation of tree and forest biomass is key to evaluating forest ecosystem functions and the global carbon cycle. Allometric equations that estimate tree biomass from a set of predictors, such as stem diameter and tree height, are commonly used. Most allometric equations are site specific, usually developed from a small number of trees harvested in a small area, and are either species specific or ignore interspecific differences in allometry. Due to lack of site-specific allometries, local equations are often applied to sites for which they were not originally developed (foreign sites), sometimes leading to large errors in biomass estimates. In this study, we developed generic allometric equations for aboveground biomass and component (stem, branch, leaf, and root) biomass using large, compiled data sets of 1203 harvested trees belonging to 102 species (60 deciduous angiosperm, 32 evergreen angiosperm, and 10 evergreen gymnosperm species) from 70 boreal, temperate, and subtropical natural forests in Japan. The best generic equations provided better biomass estimates than did local equations that were applied to foreign sites. The best generic equations included explanatory variables that represent interspecific differences in allometry in addition to stem diameter, reducing error by 4-12% compared to the generic equations that did not include the interspecific difference. Different explanatory variables were selected for different components. For aboveground and stem biomass, the best generic equations had species-specific wood specific gravity as an explanatory variable. For branch, leaf, and root biomass, the best equations had functional types (deciduous angiosperm, evergreen angiosperm, and evergreen gymnosperm) instead of functional traits (wood specific gravity or leaf mass per area), suggesting importance of other traits in addition to these traits, such as canopy and root architecture. Inclusion of tree height in addition to stem diameter improved

  2. Methodology for estimating biomass energy potential and its application to Colombia

    International Nuclear Information System (INIS)

    Gonzalez-Salazar, Miguel Angel; Morini, Mirko; Pinelli, Michele; Spina, Pier Ruggero; Venturini, Mauro; Finkenrath, Matthias; Poganietz, Witold-Roger

    2014-01-01

    Highlights: • Methodology to estimate the biomass energy potential and its uncertainty at a country level. • Harmonization of approaches and assumptions in existing assessment studies. • The theoretical and technical biomass energy potential in Colombia are estimated in 2010. - Abstract: This paper presents a methodology to estimate the biomass energy potential and its associated uncertainty at a country level when quality and availability of data are limited. The current biomass energy potential in Colombia is assessed following the proposed methodology and results are compared to existing assessment studies. The proposed methodology is a bottom-up resource-focused approach with statistical analysis that uses a Monte Carlo algorithm to stochastically estimate the theoretical and the technical biomass energy potential. The paper also includes a proposed approach to quantify uncertainty combining a probabilistic propagation of uncertainty, a sensitivity analysis and a set of disaggregated sub-models to estimate reliability of predictions and reduce the associated uncertainty. Results predict a theoretical energy potential of 0.744 EJ and a technical potential of 0.059 EJ in 2010, which might account for 1.2% of the annual primary energy production (4.93 EJ)

  3. Microbial Biomass and Activity in Geomorphic Features in Forested and Urban Restored and Degraded Streams

    Science.gov (United States)

    Geomorphic spatial heterogeneity affects sediment denitrification, an anaerobic microbial process that results in the loss of nitrogen (N), and other anaerobic microbial processes such as methanogenesis in urban streams. We measured sediment denitrification potential (DEA), metha...

  4. Afforestation impacts microbial biomass and its natural {sup 13}C and {sup 15}N abundance in soil aggregates in central China

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Junjun; Zhang, Qian; Yang, Fan; Lei, Yao; Zhang, Quanfa; Cheng, Xiaoli, E-mail: xlcheng@fudan.edu.cn

    2016-10-15

    We investigated soil microbial biomass and its natural abundance of δ{sup 13}C and δ{sup 15}N in aggregates (> 2000 μm, 250–2000 μm, 53–250 μm and < 53 μm) of afforested (implementing woodland and shrubland plantations) soils, adjacent croplands and open area (i.e., control) in the Danjiangkou Reservoir area of central China. The afforested soils averaged higher microbial biomass carbon (MBC) and nitrogen (MBN) levels in all aggregates than in open area and cropland, with higher microbial biomass in micro-aggregates (< 250 μm) than in macro-aggregates (> 2000 μm). The δ{sup 13}C of soil microbial biomass was more enriched in woodland soils than in other land use types, while δ{sup 15}N of soil microbial biomass was more enriched compared with that of organic soil in all land use types. The δ{sup 13}C and δ{sup 15}N of microbial biomass were positively correlated with the δ{sup 13}C and δ{sup 15}N of organic soil across aggregates and land use types, whereas the {sup 13}C and {sup 15}N enrichment of microbial biomass exhibited linear decreases with the corresponding C:N ratio of organic soil. Our results suggest that shifts in the natural {sup 13}C and {sup 15}N abundance of microbial biomass reflect changes in the stabilization and turnover of soil organic matter (SOM) and thereby imply that afforestation can greatly impact SOM accumulation over the long-term. - Highlights: • Afforested soils averaged higher microbial biomass in all aggregates than cropland. • Microbial biomass was higher in micro-aggregates than in macro-aggregates. • δ{sup 13}C and δ{sup 15}N of microbe positively correlated with δ{sup 13}C and δ{sup 15}N of organic soil. • {sup 13}C and {sup 15}N enrichment of microbe was negatively related to with soil C:N ratio.

  5. Appendix C: Biomass Program inputs for FY 2008 benefits estimates

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-01-18

    Document summarizes the results of the benefits analysis of EERE’s programs, as described in the FY 2008 Budget Request. EERE estimates benefits for its overall portfolio and nine Research, Development, Demonstration, and Deployment (RD3) programs.

  6. Allometric Models Based on Bayesian Frameworks Give Better Estimates of Aboveground Biomass in the Miombo Woodlands

    Directory of Open Access Journals (Sweden)

    Shem Kuyah

    2016-02-01

    Full Text Available The miombo woodland is the most extensive dry forest in the world, with the potential to store substantial amounts of biomass carbon. Efforts to obtain accurate estimates of carbon stocks in the miombo woodlands are limited by a general lack of biomass estimation models (BEMs. This study aimed to evaluate the accuracy of most commonly employed allometric models for estimating aboveground biomass (AGB in miombo woodlands, and to develop new models that enable more accurate estimation of biomass in the miombo woodlands. A generalizable mixed-species allometric model was developed from 88 trees belonging to 33 species ranging in diameter at breast height (DBH from 5 to 105 cm using Bayesian estimation. A power law model with DBH alone performed better than both a polynomial model with DBH and the square of DBH, and models including height and crown area as additional variables along with DBH. The accuracy of estimates from published models varied across different sites and trees of different diameter classes, and was lower than estimates from our model. The model developed in this study can be used to establish conservative carbon stocks required to determine avoided emissions in performance-based payment schemes, for example in afforestation and reforestation activities.

  7. Estimating forest and woodland aboveground biomass using active and passive remote sensing

    Science.gov (United States)

    Wu, Zhuoting; Dye, Dennis G.; Vogel, John M.; Middleton, Barry R.

    2016-01-01

    Aboveground biomass was estimated from active and passive remote sensing sources, including airborne lidar and Landsat-8 satellites, in an eastern Arizona (USA) study area comprised of forest and woodland ecosystems. Compared to field measurements, airborne lidar enabled direct estimation of individual tree height with a slope of 0.98 (R2 = 0.98). At the plot-level, lidar-derived height and intensity metrics provided the most robust estimate for aboveground biomass, producing dominant species-based aboveground models with errors ranging from 4 to 14Mg ha –1 across all woodland and forest species. Landsat-8 imagery produced dominant species-based aboveground biomass models with errors ranging from 10 to 28 Mg ha –1. Thus, airborne lidar allowed for estimates for fine-scale aboveground biomass mapping with low uncertainty, while Landsat-8 seems best suited for broader spatial scale products such as a national biomass essential climate variable (ECV) based on land cover types for the United States.

  8. Leaf-Cutter Ant Fungus Gardens Are Biphasic Mixed Microbial Bioreactors That Convert Plant Biomass to Polyols with Biotechnological Applications

    Science.gov (United States)

    Somera, Alexandre F.; Lima, Adriel M.; dos Santos-Neto, Álvaro J.; Lanças, Fernando M.

    2015-01-01

    Leaf-cutter ants use plant matter to culture the obligate mutualistic basidiomycete Leucoagaricus gongylophorus. This fungus mediates ant nutrition on plant resources. Furthermore, other microbes living in the fungus garden might also contribute to plant digestion. The fungus garden comprises a young sector with recently incorporated leaf fragments and an old sector with partially digested plant matter. Here, we show that the young and old sectors of the grass-cutter Atta bisphaerica fungus garden operate as a biphasic solid-state mixed fermenting system. An initial plant digestion phase occurred in the young sector in the fungus garden periphery, with prevailing hemicellulose and starch degradation into arabinose, mannose, xylose, and glucose. These products support fast microbial growth but were mostly converted into four polyols. Three polyols, mannitol, arabitol, and inositol, were secreted by L. gongylophorus, and a fourth polyol, sorbitol, was likely secreted by another, unidentified, microbe. A second plant digestion phase occurred in the old sector, located in the fungus garden core, comprising stocks of microbial biomass growing slowly on monosaccharides and polyols. This biphasic operation was efficient in mediating symbiotic nutrition on plant matter: the microbes, accounting for 4% of the fungus garden biomass, converted plant matter biomass into monosaccharides and polyols, which were completely consumed by the resident ants and microbes. However, when consumption was inhibited through laboratory manipulation, most of the plant polysaccharides were degraded, products rapidly accumulated, and yields could be preferentially switched between polyols and monosaccharides. This feature might be useful in biotechnology. PMID:25911490

  9. Effects of nitrogen and phosphorus additions on soil microbial biomass and community structure in two reforested tropical forests.

    Science.gov (United States)

    Liu, Lei; Gundersen, Per; Zhang, Wei; Zhang, Tao; Chen, Hao; Mo, Jiangming

    2015-09-23

    Elevated nitrogen (N) deposition may aggravate phosphorus (P) deficiency in forests in the warm humid regions of China. To our knowledge, the interactive effects of long-term N deposition and P availability on soil microorganisms in tropical replanted forests remain unclear. We conducted an N and P manipulation experiment with four treatments: control, N addition (15 g N m(-2)·yr(-1)), P addition (15 g P m(-2)·yr(-1)), and N and P addition (15 + 15 g N and P m(-2)·yr(-1), respectively) in disturbed (planted pine forest with recent harvests of understory vegetation and litter) and rehabilitated (planted with pine, but mixed with broadleaf returning by natural succession) forests in southern China. Nitrogen addition did not significantly affect soil microbial biomass, but significantly decreased the abundance of gram-negative bacteria PLFAs in both forest types. Microbial biomass increased significantly after P addition in the disturbed forest but not in the rehabilitated forest. No interactions between N and P additions on soil microorganisms were observed in either forest type. Our results suggest that microbial growth in replanted forests of southern China may be limited by P rather than by N, and this P limitation may be greater in disturbed forests.

  10. Temporal variations in microbial biomass C and cellulolytic enzyme activity in arable soils: effects of organic matter input

    DEFF Research Database (Denmark)

    Debosz, K.; Rasmussen, Peter Have; Pedersen, A. R.

    1999-01-01

    Temporal variations in soil microbial biomass C concentration and in activity of extracellular enzymes of the cellulolytic complex were investigated in a field experiment after eight years of cultivation with either low organic matter input (low-OM) or high organic matter input (high-OM). The cul......Temporal variations in soil microbial biomass C concentration and in activity of extracellular enzymes of the cellulolytic complex were investigated in a field experiment after eight years of cultivation with either low organic matter input (low-OM) or high organic matter input (high......-OM). The cultivation systems differed in whether their source of fertiliser was mainly mineral or organic, in whether a winter cover crop was grown, and whether straw was mulched or removed. Sampling occurred at approximately monthly intervals, over a period of two years. Distinct temporal variations in microbial......) and an endocellulase activity of 44.2 +/- 1.1 nmol g(-1) h(-1). (C) 1999 Elsevier Science B.V. All rights reserved....

  11. The Use of Fire Radiative Power to Estimate the Biomass Consumption Coefficient for Temperate Grasslands in the Atlantic Forest Biome

    Directory of Open Access Journals (Sweden)

    Bibiana Salvador Cabral da Costa

    Full Text Available Abstract Every year, many active fire spots are identified in the satellite images of the southern Brazilian grasslands in the Atlantic Forest biome and Pampa biome. Fire Radiative Power (FRP is a technique that uses remotely sensed data to quantify burned biomass. FRP measures the radiant energy released per time unit by burning vegetation. This study aims to use satellite and field data to estimate the biomass consumption rate and the biomass consumption coefficient for the southern Brazilian grasslands. Three fire points were identified in satellite FRP products. These data were combined with field data, collected through literature review, to calculate the biomass consumption coefficient. The type of vegetation is an important variable in the estimation of the biomass consumption coefficient. The biomass consumption rate was estimated to be 2.237 kg s-1 for the southern Brazilian grasslands in Atlantic Forest biome, and the biomass consumption coefficient was estimated to be 0.242 kg MJ-1.

  12. Landsat Imagery-Based Above Ground Biomass Estimation and Change Investigation Related to Human Activities

    Directory of Open Access Journals (Sweden)

    Chaofan Wu

    2016-02-01

    Full Text Available Forest biomass is a significant indicator for substance accumulation and forest succession, and a spatiotemporal biomass map would provide valuable information for forest management and scientific planning. In this study, Landsat imagery and field data cooperated with a random forest regression approach were used to estimate spatiotemporal Above Ground Biomass (AGB in Fuyang County, Zhejiang Province of East China. As a result, the AGB retrieval showed an increasing trend for the past decade, from 74.24 ton/ha in 2004 to 99.63 ton/ha in 2013. Topography and forest management were investigated to find their relationships with the spatial distribution change of biomass. In general, the simulated AGB increases with higher elevation, especially in the range of 80–200 m, wherein AGB acquires the highest increase rate. Moreover, the forest policy of ecological forest has a positive effect on the AGB increase, particularly within the national level ecological forest. The result in this study demonstrates that human activities have a great impact on biomass distribution and change tendency. Furthermore, Landsat image-based biomass estimates would provide illuminating information for forest policy-making and sustainable development.

  13. Estimates of forest canopy height and aboveground biomass using ICESat.

    Science.gov (United States)

    Michael A. Lefsky; David J. Harding; Michael Keller; Warren B. Cohen; Claudia C. Carabajal; Fernando Del Bom; Maria O. Hunter; Raimundo Jr. de Oliveira

    2005-01-01

    Exchange of carbon between forests and the atmosphere is a vital component of the global carbon cycle. Satellite laser altimetry has a unique capability for estimating forest canopy height, which has a direct and increasingly well understood relationship to aboveground carbon storage. While the Geoscience Laser Altimeter System (GLAS) onboard the Ice, Cloud and land...

  14. REGIONAL ESTIMATION OF CURRENT AND FUTURE FOREST BIOMASS. (R828785)

    Science.gov (United States)

    The 90,674 wildland fires that burned 2.9 million ha at an estimated suppression cost of $1.6 billion in the United States during the 2000 fire season demonstrated that forest fuel loading has become a hazard to life, property, and ecosystem health as a result of past fire exc...

  15. Estimation of arboreal lichen biomass available to woodland caribou in Hudson Bay lowland black spruce sites

    Directory of Open Access Journals (Sweden)

    Sarah K. Proceviat

    2003-04-01

    Full Text Available An arboreal lichen index to be utilized in assessing woodland caribou habitat throughout northeastern Ontario was developed. The "index" was comprised of 5 classes, which differentiated arboreal lichen biomass on black spruce trees, ranging from maximal quantities of arboreal lichen (class 5 to minimal amounts of arboreal lichen (class 1. This arboreal lichen index was subsequently used to estimate the biomass of arboreal lichen available to woodland caribou on lowland black spruce sites ranging in age from 1 year to 150 years post-harvest. A total of 39 sites were assessed and significant differences in arboreal lichen biomass were found, with a positive linear relationship between arboreal lichen biomass and forest age. It is proposed that the index be utilized by government and industry as a means of assessing the suitability of lowland black spruce habitat for woodland caribou in this region.

  16. Estimation of Biomass and Canopy Height in Bermudagrass, Alfalfa, and Wheat Using Ultrasonic, Laser, and Spectral Sensors

    Directory of Open Access Journals (Sweden)

    Jeremy Joshua Pittman

    2015-01-01

    Full Text Available Non-destructive biomass estimation of vegetation has been performed via remote sensing as well as physical measurements. An effective method for estimating biomass must have accuracy comparable to the accepted standard of destructive removal. Estimation or measurement of height is commonly employed to create a relationship between height and mass. This study examined several types of ground-based mobile sensing strategies for forage biomass estimation. Forage production experiments consisting of alfalfa (Medicago sativa L., bermudagrass [Cynodon dactylon (L. Pers.], and wheat (Triticum aestivum L. were employed to examine sensor biomass estimation (laser, ultrasonic, and spectral as compared to physical measurements (plate meter and meter stick and the traditional harvest method (clipping. Predictive models were constructed via partial least squares regression and modeled estimates were compared to the physically measured biomass. Least significant difference separated mean estimates were examined to evaluate differences in the physical measurements and sensor estimates for canopy height and biomass. Differences between methods were minimal (average percent error of 11.2% for difference between predicted values versus machine and quadrat harvested biomass values (1.64 and 4.91 t·ha−1, respectively, except at the lowest measured biomass (average percent error of 89% for harvester and quad harvested biomass < 0.79 t·ha−1 and greatest measured biomass (average percent error of 18% for harvester and quad harvested biomass >6.4 t·ha−1. These data suggest that using mobile sensor-based biomass estimation models could be an effective alternative to the traditional clipping method for rapid, accurate in-field biomass estimation.

  17. A microbial bioassay to estimate nutrient availability in organic fertilizers; field calibration:

    International Nuclear Information System (INIS)

    Salas, E.; Ramirez, C.

    2001-01-01

    A good correlation was recently shown between the increase in the microbial biomass (BM) in a mixture of soil/organic amendment and the growth of a test plant, sorghum, in the same substrate. This work reports the validation of the microbial assay as a potential guide to establish the fertilization rate for organic fertilizers such as compost under field conditions. A field trial was established with green pepper (Capsicum annum L.) and tomato (Lycopersicum esculentum L) as test plants. Treatments were soil alone or amended with 10% (W/W) of organic amendments of contrasting nutrient value, namely: chicken manure (CM), compost (C), bocashi (B), vermicompost (V) and coffe hulls (Br). A complete randomized block design with 4 replicates was used. The following variables were determined: plant dry weight (PSC) and fresh fruit weight (PFF) for green pepper, 97 days after showing; for tomato, plant dry weight (PST) was determined 32 days after showing. For the microbial biomass a complete randomized block design was also used, with 6 replicates, for the same mixtures. Microbial biomass was determined 2 days after amendment with glucose (0.8%) using the substrate- induce respiration assay. The organic amendments CM, C and B induced the highest values for BM as well as fro PSC, PFF and PST, which indicates a high nutrient availability for these organic amendments, whereas the organic amendments V and Br showed the lowest values (P [es

  18. Generalized allometric regression to estimate biomass of Populus in short-rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Ben Brahim, Mohammed; Gavaland, Andre; Cabanettes, Alain [INRA Centre de Toulouse, Castanet-Tolosane Cedex (France). Unite Agroforesterie et Foret Paysanne

    2000-07-01

    Data from four different stands were combined to establish a single generalized allometric equation to estimate above-ground biomass of individual Populus trees grown on short-rotation coppice. The generalized model was performed using diameter at breast height, the mean diameter and the mean height of each site as dependent variables and then compared with the stand-specific regressions using F-test. Results showed that this single regression estimates tree biomass well at each stand and does not introduce bias with increasing diameter.

  19. Estimation of crown biomass of Pinus pinaster stands and shrubland above-ground biomass using forest inventory data, remotely sensed imagery and spatial prediction models

    Science.gov (United States)

    H. Viana; J. Aranha; D. Lopes; Warren B. Cohen

    2012-01-01

    Spatially crown biomass of Pinus pinaster stands and shrubland above-ground biomass (AGB) estimation was carried-out in a region located in Centre-North Portugal, by means of different approaches including forest inventory data, remotely sensed imagery and spatial prediction models. Two cover types (pine stands and shrubland) were inventoried and...

  20. Evaluation of the reference unit method for herbaceous biomass estimation in native grasslands of southwestern South Dakota

    Science.gov (United States)

    Eric D. Boyda

    2013-01-01

    The high costs associated with physically harvesting plant biomass may prevent sufficient data collection, which is necessary to account for the natural variability of vegetation at a landscape scale. A biomass estimation technique was previously developed using representative samples or "reference units", which eliminated the need to harvest biomass from all...

  1. Airborne laser scanner-assisted estimation of aboveground biomass change in a temperate oak-pine forest

    Science.gov (United States)

    Nicholas S. Skowronski; Kenneth L. Clark; Michael Gallagher; Richard A. Birdsey; John L. Hom

    2014-01-01

    We estimated aboveground tree biomass and change in aboveground tree biomass using repeated airborne laser scanner (ALS) acquisitions and temporally coincident ground observations of forest biomass, for a relatively undisturbed period (2004-2007; ∇07-04), a contrasting period of disturbance (2007-2009; ∇09-07...

  2. Estimating GHG emission mitigation supply curves of large-scale biomass use on a country level

    International Nuclear Information System (INIS)

    Dornburg, Veronika; Dam, Jinke van; Faaij, Andre

    2007-01-01

    This study evaluates the possible influences of a large-scale introduction of biomass material and energy systems and their market volumes on land, material and energy market prices and their feedback to greenhouse gas (GHG) emission mitigation costs. GHG emission mitigation supply curves for large-scale biomass use were compiled using a methodology that combines a bottom-up analysis of biomass applications, biomass cost supply curves and market prices of land, biomaterials and bioenergy carriers. These market prices depend on the scale of biomass use and the market volume of materials and energy carriers and were estimated using own-price elasticities of demand. The methodology was demonstrated for a case study of Poland in the year 2015 applying different scenarios on economic development and trade in Europe. For the key technologies considered, i.e. medium density fibreboard, poly lactic acid, electricity and methanol production, GHG emission mitigation costs increase strongly with the scale of biomass production. Large-scale introduction of biomass use decreases the GHG emission reduction potential at costs below 50 Euro /Mg CO 2eq with about 13-70% depending on the scenario. Biomaterial production accounts for only a small part of this GHG emission reduction potential due to relatively small material markets and the subsequent strong decrease of biomaterial market prices at large scale of production. GHG emission mitigation costs depend strongly on biomass supply curves, own-price elasticity of land and market volumes of bioenergy carriers. The analysis shows that these influences should be taken into account for developing biomass implementations strategies

  3. Indirect methods of tree biomass estimation and their uncertainties ...

    African Journals Online (AJOL)

    Depending on data availability (dbh only or both dbh and total tree height) either of the models may be applied to generate satisfactory estimates of tree volume needed for planning and decision-making in management of mangrove forests. The study found an overall mean FF value of 0.65 ± 0.03 (SE), 0.56 ± 0.03 (SE) and ...

  4. Estimation of rumen microbial-nitrogen of sheep using urinary excretion of purine derivatives

    International Nuclear Information System (INIS)

    Liu Dasen; Shan Anshan

    2004-01-01

    Determination of rumen microbial-nitrogen of sheep using urinary excretion of purine derivative was studied. Uric acid and xanthine + hypoxanthine were not affected by diets, but total purine derivatives for 1 mg borax/kg diet was higher than other diets (p<0.05). Microbial-nitrogen estimated from allantoin was not affected by diets, but that of 1 mg borax/kg diet estimated from total purine derivatives was higher than other diets (p<0.05). Microbial-nitrogen estimated from total purine derivatives was higher than that from allantoin

  5. Improved Forest Biomass and Carbon Estimations Using Texture Measures from WorldView-2 Satellite Data

    Directory of Open Access Journals (Sweden)

    Sandra Eckert

    2012-03-01

    Full Text Available Accurate estimation of aboveground biomass and carbon stock has gained importance in the context of the United Nations Framework Convention on Climate Change (UNFCCC and the Kyoto Protocol. In order to develop improved forest stratum–specific aboveground biomass and carbon estimation models for humid rainforest in northeast Madagascar, this study analyzed texture measures derived from WorldView-2 satellite data. A forest inventory was conducted to develop stratum-specific allometric equations for dry biomass. On this basis, carbon was calculated by applying a conversion factor. After satellite data preprocessing, vegetation indices, principal components, and texture measures were calculated. The strength of their relationships with the stratum-specific plot data was analyzed using Pearson’s correlation. Biomass and carbon estimation models were developed by performing stepwise multiple linear regression. Pearson’s correlation coefficients revealed that (a texture measures correlated more with biomass and carbon than spectral parameters, and (b correlations were stronger for degraded forest than for non-degraded forest. For degraded forest, the texture measures of Correlation, Angular Second Moment, and Contrast, derived from the red band, contributed to the best estimation model, which explained 84% of the variability in the field data (relative RMSE = 6.8%. For non-degraded forest, the vegetation index EVI and the texture measures of Variance, Mean, and Correlation, derived from the newly introduced coastal blue band, both NIR bands, and the red band, contributed to the best model, which explained 81% of the variability in the field data (relative RMSE = 11.8%. These results indicate that estimation of tropical rainforest biomass/carbon, based on very high resolution satellite data, can be improved by (a developing and applying forest stratum–specific models, and (b including textural information in addition to spectral information.

  6. Extension of biomass estimates to pre-assessment periods using density dependent surplus production approach.

    Directory of Open Access Journals (Sweden)

    Jan Horbowy

    Full Text Available Biomass reconstructions to pre-assessment periods for commercially important and exploitable fish species are important tools for understanding long-term processes and fluctuation on stock and ecosystem level. For some stocks only fisheries statistics and fishery dependent data are available, for periods before surveys were conducted. The methods for the backward extension of the analytical assessment of biomass for years for which only total catch volumes are available were developed and tested in this paper. Two of the approaches developed apply the concept of the surplus production rate (SPR, which is shown to be stock density dependent if stock dynamics is governed by classical stock-production models. The other approach used a modified form of the Schaefer production model that allows for backward biomass estimation. The performance of the methods was tested on the Arctic cod and North Sea herring stocks, for which analytical biomass estimates extend back to the late 1940s. Next, the methods were applied to extend biomass estimates of the North-east Atlantic mackerel from the 1970s (analytical biomass estimates available to the 1950s, for which only total catch volumes were available. For comparison with other methods which employs a constant SPR estimated as an average of the observed values, was also applied. The analyses showed that the performance of the methods is stock and data specific; the methods that work well for one stock may fail for the others. The constant SPR method is not recommended in those cases when the SPR is relatively high and the catch volumes in the reconstructed period are low.

  7. Incorporating uncertainty analysis into life cycle estimates of greenhouse gas emissions from biomass production

    International Nuclear Information System (INIS)

    Johnson, David R.; Willis, Henry H.; Curtright, Aimee E.; Samaras, Constantine; Skone, Timothy

    2011-01-01

    Before further investments are made in utilizing biomass as a source of renewable energy, both policy makers and the energy industry need estimates of the net greenhouse gas (GHG) reductions expected from substituting biobased fuels for fossil fuels. Such GHG reductions depend greatly on how the biomass is cultivated, transported, processed, and converted into fuel or electricity. Any policy aiming to reduce GHGs with biomass-based energy must account for uncertainties in emissions at each stage of production, or else it risks yielding marginal reductions, if any, while potentially imposing great costs. This paper provides a framework for incorporating uncertainty analysis specifically into estimates of the life cycle GHG emissions from the production of biomass. We outline the sources of uncertainty, discuss the implications of uncertainty and variability on the limits of life cycle assessment (LCA) models, and provide a guide for practitioners to best practices in modeling these uncertainties. The suite of techniques described herein can be used to improve the understanding and the representation of the uncertainties associated with emissions estimates, thus enabling improved decision making with respect to the use of biomass for energy and fuel production. -- Highlights: → We describe key model, scenario and data uncertainties in LCAs of biobased fuels. → System boundaries and allocation choices should be consistent with study goals. → Scenarios should be designed around policy levers that can be controlled. → We describe a new way to analyze the importance of covariance between inputs.

  8. Evaluation of the Environmental DNA Method for Estimating Distribution and Biomass of Submerged Aquatic Plants.

    Science.gov (United States)

    Matsuhashi, Saeko; Doi, Hideyuki; Fujiwara, Ayaka; Watanabe, Sonoko; Minamoto, Toshifumi

    2016-01-01

    The environmental DNA (eDNA) method has increasingly been recognized as a powerful tool for monitoring aquatic animal species; however, its application for monitoring aquatic plants is limited. To evaluate eDNA analysis for estimating the distribution of aquatic plants, we compared its estimated distributions with eDNA analysis, visual observation, and past distribution records for the submerged species Hydrilla verticillata. Moreover, we conducted aquarium experiments using H. verticillata and Egeria densa and analyzed the relationships between eDNA concentrations and plant biomass to investigate the potential for biomass estimation. The occurrences estimated by eDNA analysis closely corresponded to past distribution records, and eDNA detections were more frequent than visual observations, indicating that the method is potentially more sensitive. The results of the aquarium experiments showed a positive relationship between plant biomass and eDNA concentration; however, the relationship was not always significant. The eDNA concentration peaked within three days of the start of the experiment in most cases, suggesting that plants do not release constant amounts of DNA. These results showed that eDNA analysis can be used for distribution surveys, and has the potential to estimate the biomass of aquatic plants.

  9. Benchmarking electrical methods for rapid estimation of root biomass.

    Science.gov (United States)

    Postic, François; Doussan, Claude

    2016-01-01

    To face climate change and subsequent rainfall instabilities, crop breeding strategies now include root traits phenotyping. Rapid estimation of root traits in controlled conditions can be achieved by using parallel electrical capacitance and its linear correlation with root dry mass. The aim of the present study was to improve robustness and efficiency of methods based on capacitance and other electrical variables, such as serial/parallel resistance, conductance, impedance or reactance. Using different electrode configurations and stem contact electrodes, we have measured the electrical impedance spectra of wheat plants grown in pots filled with three types of soil. For each configuration, parallel capacitance and other linearly independent electrical variables were computed and their quality as root dry mass estimator was evaluated by a 'sensitivity score' that we derived from Pearson's correlation coefficient r and linear regression parameters. The highest sensitivity score was obtained by parallel capacitance at an alternating current frequency of 116 Hz in three-terminal configuration. Using a clamp, instead of a needle, as a stem electrode did not significantly affect the capacitance measurements. Finally, in handheld LCR meter equivalent conditions, capacitance had the highest sensitivity score and determination coefficient (r (2) = 0.52) at 10 kHz frequency. Our benchmarking of linear correlations between different electrical variables and root dry mass enables to determine more coherent practices for ensuring a sensitive and robust root dry mass estimation, including in handheld LCR meter conditions. This would enhance the value of electrical capacitance as a tool for screening crops in relation with root systems in breeding programs.

  10. Nitrogen deposition and management practices increase soil microbial biomass carbon but decrease diversity in Moso bamboo plantations

    Science.gov (United States)

    Li, Quan; Song, Xinzhang; Gu, Honghao; Gao, Fei

    2016-06-01

    Because microbial communities play a key role in carbon (C) and nitrogen (N) cycling, changes in the soil microbial community may directly affect ecosystem functioning. However, the effects of N deposition and management practices on soil microbes are still poorly understood. We studied the effects of these two factors on soil microbial biomass carbon (MBC) and community composition in Moso bamboo plantations using high-throughput sequencing of the 16S rRNA gene. Plantations under conventional (CM) or intensive management (IM) were subjected to one of four N treatments for 30 months. IM and N addition, both separately and in combination, significantly increased soil MBC while decreasing bacterial diversity. However, increases in soil MBC were inhibited when N addition exceeded 60 kg N•ha-1•yr-1. IM increased the relative abundances of Actinobacteria and Crenarchaeota but decreased that of Acidobacteria. N addition increased the relative abundances of Acidobacteria, Crenarchaeota, and Actinobacteria but decreased that of Proteobacteria. Soil bacterial diversity was significantly related to soil pH, C/N ratio, and nitrogen and available phosphorus content. Management practices exerted a greater influence over regulation of the soil MBC and microbial diversity compared to that of N deposition in Moso bamboo plantations.

  11. Abundance and biomass responses of microbial food web components to hydrology and environmental gradients within a floodplain of the River Danube.

    Science.gov (United States)

    Palijan, Goran

    2012-07-01

    This study investigated the relationships of time-dependent hydrological variability and selected microbial food web components. Samples were collected monthly from the Kopački Rit floodplain in Croatia, over a period of 19 months, for analysis of bacterioplankton abundance, cell size and biomass; abundance of heterotrophic nanoflagellates and nanophytoplankton; and concentration of chlorophyll a. Similar hydrological variability at different times of the year enabled partition of seasonal effects from hydrological changes on microbial community properties. The results suggested that, unlike some other studies investigating sites with different connectivity, bacterioplankton abundance, and phytoplankton abundance and biomass increased during lentic conditions. At increasing water level, nanophytoplankton showed lower sensitivity to disturbance in comparison with total phytoplankton biomass: this could prolong autotrophic conditions within the floodplain. Bacterioplankton biomass, unlike phytoplankton, was not impacted by hydrology. The bacterial biomass less affected by hydrological changes can be an important additional food component for the floodplain food web. The results also suggested a mechanism controlling bacterial cell size independent of hydrology, as bacterial cell size was significantly decreased as nanoflagellate abundance increased. Hydrology, regardless of seasonal sucession, has the potential to structure microbial food webs, supporting microbial development during lentic conditions. Conversely, other components appear unaffected by hydrology or may be more strongly controlled by biotic interactions. This research, therefore, adds to understanding on microbial food web interactions in the context of flood and flow pulses in river-floodplain ecosystems.

  12. Psychrophilic Biomass Producers in the Trophic Chain of the Microbial Community of Lake Untersee, Antarctica

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.

    2010-01-01

    The study of photosynthetic microorganisms from the Lake Untersee samples showed dispersed distribution of phototrophs within 80 m water column. Lake Untersee represents a unique ecosystem that experienced complete isolation: sealed by the Anuchin Glacier for many millennia. Consequently, its biocenosis has evolved over a significant period of time without exchange or external interaction with species from other environments. The major producers of organic matter in Lake Untersee are represented by phototrophic and chemolithotrophic microorganisms. This is the traditional trophic scheme for lacustrine ecosystems on Earth. Among the phototrophs, diatoms were not found, which differentiates this lake from other known ecosystems. The dominant species among phototrophs was Chlamydomonas sp. with typical morphostructure: green chloroplasts, bright red round spot, and two polar flagella near the opening. As expected, the physiology of studied phototrophs was limited by low temperature, which defined them as obligate psychrophilic microorganisms. By the quantity estimation of methanogenesis in this lake, the litho-autotrophic production of organic matter is competitive with phototrophic production. However, pure cultures of methanogens have not yet been obtained. We discuss the primary producers of organic matter and the participation of our novel psychrophilic homoacetogen into the litho-autotrophic link of biomass production in Lake Untersee.

  13. The potential of spectral mixture analysis to improve the estimation accuracy of tropical forest biomass

    NARCIS (Netherlands)

    Basuki, T.M.; Skidmore, A.K.; Laake, van P.E.; Duren, van I.C.; Hussin, Y.A.

    2012-01-01

    A main limitation of pixel-based vegetation indices or reflectance values for estimating above-ground biomass is that they do not consider the mixed spectral components on the earth's surface covered by a pixel. In this research, we decomposed mixed reflectance in each pixel before developing models

  14. Estimating leaf area and leaf biomass of open-grown deciduous urban trees

    Science.gov (United States)

    David J. Nowak

    1996-01-01

    Logarithmic regression equations were developed to predict leaf area and leaf biomass for open-grown deciduous urban trees based on stem diameter and crown parameters. Equations based on crown parameters produced more reliable estimates. The equations can be used to help quantify forest structure and functions, particularly in urbanizing and urban/suburban areas.

  15. Wood Specific Gravity Variation with Height and Its Implications for Biomass Estimation

    Science.gov (United States)

    Michael C. Wiemann; G. Bruce Williamson

    2014-01-01

    Wood specific gravity (SG) is widely employed by ecologists as a key variable in estimates of biomass. When it is important to have nondestructive methods for sampling wood for SG measurements, cores are extracted with an increment borer. While boring is a relatively difficult task even at breast height sampling, it is impossible at ground level and arduous at heights...

  16. Uncertainty of Forest Biomass Estimates in North Temperate Forests Due to Allometry: Implications for Remote Sensing

    Directory of Open Access Journals (Sweden)

    Razi Ahmed

    2013-06-01

    Full Text Available Estimates of above ground biomass density in forests are crucial for refining global climate models and understanding climate change. Although data from field studies can be aggregated to estimate carbon stocks on global scales, the sparsity of such field data, temporal heterogeneity and methodological variations introduce large errors. Remote sensing measurements from spaceborne sensors are a realistic alternative for global carbon accounting; however, the uncertainty of such measurements is not well known and remains an active area of research. This article describes an effort to collect field data at the Harvard and Howland Forest sites, set in the temperate forests of the Northeastern United States in an attempt to establish ground truth forest biomass for calibration of remote sensing measurements. We present an assessment of the quality of ground truth biomass estimates derived from three different sets of diameter-based allometric equations over the Harvard and Howland Forests to establish the contribution of errors in ground truth data to the error in biomass estimates from remote sensing measurements.

  17. Allometric models for estimating the aboveground biomass of the mangrove Rhizophora mangle

    Directory of Open Access Journals (Sweden)

    Heide Vanessa Souza Santos

    Full Text Available Abstract The development of species-specific allometric models is critical to the improvement of aboveground biomass estimates, as well as to the estimation of carbon stock and sequestration in mangrove forests. This study developed allometric equations for estimating aboveground biomass of Rhizophora mangle in the mangroves of the estuary of the São Francisco River, in northeastern Brazil. Using a sample of 74 trees, simple linear regression analysis was used to test the dependence of biomass (total and per plant part on size, considering both transformed (ln and not-transformed data. Best equations were considered as those with the lowest standard error of estimation (SEE and highest adjusted coefficient of determination (R2a. The ln-transformed equations showed better results, with R2a near 0.99 in most cases. The equations for reproductive parts presented low R2a values, probably attributed to the seasonal nature of this compartment. "Basal Area2 × Height" showed to be the best predictor, present in most of the best-fitted equations. The models presented here can be considered reliable predictors of the aboveground biomass of R. mangle in the NE-Brazilian mangroves as well as in any site were this widely distributed species present similar architecture to the trees used in the present study.

  18. Top-down estimates of biomass burning emissions of black carbon in the western United States

    Science.gov (United States)

    Y. H. Mao; Q. B. Li; D. Chen; L. Zhang; W. -M. Hao; K.-N. Liou

    2014-01-01

    We estimate biomass burning and anthropogenic emissions of black carbon (BC) in the western US for May-October 2006 by inverting surface BC concentrations from the Interagency Monitoring of PROtected Visual Environment (IMPROVE) network using a global chemical transport model. We first use active fire counts from the Moderate Resolution Imaging Spectroradiometer (MODIS...

  19. Allometric equations for estimating tree biomass in restored mixed-species Atlantic Forest stands

    Science.gov (United States)

    Lauro Rodrigues Nogueira; Vera Lex Engel; John A. Parrotta; Antonio Carlos Galvão de Melo; Danilo Scorzoni Ré

    2014-01-01

    Restoration of Atlantic Forests is receiving increasing attention because of its role in both biodiversity conservation and carbon sequestration for global climate change mitigation. This study was carried out in an Atlantic Forest restoration project in the south-central region of São Paulo State – Brazil to develop allometric equations to estimate tree biomass of...

  20. Using endmembers in AVIRIS images to estimate changes in vegetative biomass

    Science.gov (United States)

    Smith, Milton O.; Adams, John B.; Ustin, Susan L.; Roberts, Dar A.

    1992-01-01

    Field techniques for estimating vegetative biomass are labor intensive, and rarely are used to monitor changes in biomass over time. Remote-sensing offers an attractive alternative to field measurements; however, because there is no simple correspondence between encoded radiance in multispectral images and biomass, it is not possible to measure vegetative biomass directly from AVIRIS images. Ways to estimate vegetative biomass by identifying community types and then applying biomass scalars derived from field measurements are investigated. Field measurements of community-scale vegetative biomass can be made, at least for local areas, but it is not always possible to identify vegetation communities unambiguously using remote measurements and conventional image-processing techniques. Furthermore, even when communities are well characterized in a single image, it typically is difficult to assess the extent and nature of changes in a time series of images, owing to uncertainties introduced by variations in illumination geometry, atmospheric attenuation, and instrumental responses. Our objective is to develop an improved method based on spectral mixture analysis to characterize and identify vegetative communities, that can be applied to multi-temporal AVIRIS and other types of images. In previous studies, multi-temporal data sets (AVIRIS and TM) of Owens Valley, CA were analyzed and vegetation communities were defined in terms of fractions of reference (laboratory and field) endmember spectra. An advantage of converting an image to fractions of reference endmembers is that, although fractions in a given pixel may vary from image to image in a time series, the endmembers themselves typically are constant, thus providing a consistent frame of reference.

  1. Linking diagnostic features to soil microbial biomass and respiration in agricultural grassland soil

    NARCIS (Netherlands)

    Richter, A.; Huallacháin, D.O.; Doyle, E.; Clipson, N.; Leeuwen, Van J.P.; Heuvelink, G.B.; Creamer, R.E.

    2018-01-01

    The functional potential of soil ecosystems can be predicted from the activity and abundance of the microbial community in relation to key soil properties. When describing microbial community dynamics, soil physicochemical properties have traditionally been used. The extent of correlations between

  2. First-order estimate of the planktic foraminifer biomass in the modern ocean

    Directory of Open Access Journals (Sweden)

    R. Schiebel

    2012-09-01

    Full Text Available Planktic foraminifera are heterotrophic mesozooplankton of global marine abundance. The position of planktic foraminifers in the marine food web is different compared to other protozoans and ranges above the base of heterotrophic consumers. Being secondary producers with an omnivorous diet, which ranges from algae to small metazoans, planktic foraminifers are not limited to a single food source, and are assumed to occur at a balanced abundance displaying the overall marine biological productivity at a regional scale. With a new non-destructive protocol developed from the bicinchoninic acid (BCA method and nano-photospectrometry, we have analysed the protein-biomass, along with test size and weight, of 754 individual planktic foraminifers from 21 different species and morphotypes. From additional CHN analysis, it can be assumed that protein-biomass equals carbon-biomass. Accordingly, the average individual planktic foraminifer protein- and carbon-biomass amounts to 0.845 μg. Samples include symbiont bearing and symbiont-barren species from the sea surface down to 2500 m water depth. Conversion factors between individual biomass and assemblage-biomass are calculated for test sizes between 72 and 845 μm (minimum test diameter. Assemblage-biomass data presented here include 1128 sites and water depth intervals. The regional coverage of data includes the North Atlantic, Arabian Sea, Red Sea, and Caribbean as well as literature data from the eastern and western North Pacific, and covers a wide range of oligotrophic to eutrophic waters over six orders of magnitude of planktic-foraminifer assemblage-biomass (PFAB. A first order estimate of the average global planktic foraminifer biomass production (>125 μm ranges from 8.2–32.7 Tg C yr−1 (i.e. 0.008–0.033 Gt C yr−1, and might be more than three times as high including neanic and juvenile individuals adding up to 25–100 Tg C yr−1. However, this is a first

  3. Estimating the fuel moisture content to control the reciprocating grate furnace firing wet woody biomass

    International Nuclear Information System (INIS)

    Striūgas, N.; Vorotinskienė, L.; Paulauskas, R.; Navakas, R.; Džiugys, A.; Narbutas, L.

    2017-01-01

    Highlights: • Combustion of biomass with varying moisture content might lead to unstable operation of a furnace. • Method for automatic control of a furnace fired with wet biomass was developed. • Fuel moisture is estimated by cost-effective indirect method for predictive control. • Fuel moisture estimation methods and furnace control algorithm were validated in an industrial boiler. - Abstract: In small countries like Lithuania with a widespread district heating system, 5–10 MW moving grate biomass furnaces equipped with water boilers and condensing economisers are widely used. Such systems are designed for firing biomass fuels; however, varying fuel moisture, mostly in the range from 30% to 60%, complicates the automated operation. Without manual adjustment of the grate motion mode and other parameters, unstable operation or even extinction of the furnace is possible. To ensure stable furnace operation with moist fuel, the indirect method to estimate the fuel moisture content was developed based on the heat balance of the flue gas condensing economiser. The developed method was implemented into the automatic control unit of the furnace to estimate the moisture content in the feedstock and predictively adjust the furnace parameters for optimal fuel combustion. The indirect method based on the economiser heat balance was experimentally validated in a 6 MW grate-fired furnace fuelled by biomass with moisture contents of 37, 46, 50, 54 and 60%. The analysis shows that the estimated and manually measured values of the fuel moisture content do not differ by more than 3%. This deviation indicates that the indirect fuel moisture calculation method is sufficiently precise and the calculated moisture content varies proportionally to changes in the thermal capacity of the economiser. By smoothing the data using sliding weighted averaging, the oscillations of the fuel moisture content were identified.

  4. Estimates of Forest Biomass Carbon Storage in Liaoning Province of Northeast China: A Review and Assessment

    Science.gov (United States)

    Yu, Dapao; Wang, Xiaoyu; Yin, You; Zhan, Jinyu; Lewis, Bernard J.; Tian, Jie; Bao, Ye; Zhou, Wangming; Zhou, Li; Dai, Limin

    2014-01-01

    Accurate estimates of forest carbon storage and changes in storage capacity are critical for scientific assessment of the effects of forest management on the role of forests as carbon sinks. Up to now, several studies reported forest biomass carbon (FBC) in Liaoning Province based on data from China's Continuous Forest Inventory, however, their accuracy were still not known. This study compared estimates of FBC in Liaoning Province derived from different methods. We found substantial variation in estimates of FBC storage for young and middle-age forests. For provincial forests with high proportions in these age classes, the continuous biomass expansion factor method (CBM) by forest type with age class is more accurate and therefore more appropriate for estimating forest biomass. Based on the above approach designed for this study, forests in Liaoning Province were found to be a carbon sink, with carbon stocks increasing from 63.0 TgC in 1980 to 120.9 TgC in 2010, reflecting an annual increase of 1.9 TgC. The average carbon density of forest biomass in the province has increased from 26.2 Mg ha−1 in 1980 to 31.0 Mg ha−1 in 2010. While the largest FBC occurred in middle-age forests, the average carbon density decreased in this age class during these three decades. The increase in forest carbon density resulted primarily from the increased area and carbon storage of mature forests. The relatively long age interval in each age class for slow-growing forest types increased the uncertainty of FBC estimates by CBM-forest type with age class, and further studies should devote more attention to the time span of age classes in establishing biomass expansion factors for use in CBM calculations. PMID:24586881

  5. Estimate of biomass and carbon pools in disturbed and undisturbed oak forests in Tunisia

    Energy Technology Data Exchange (ETDEWEB)

    Zribi, L.; Chaar, H.; Khaldi, A.; Henchi, B.; Mouillot, F.; Gharbi, F.

    2016-07-01

    Aim of the study. To estimate biomass and carbon accumulation in a young and disturbed forest (regenerated after a tornado) and an aged cork oak forest (undisturbed forest) as well as its distribution among the different pools (tree, litter and soil). Area of study. The north west of Tunisia. Material and methods. Carbon stocks were evaluated in the above and belowground cork oak trees, the litter and the 150 cm of the soil. Tree biomass was estimated in both young and aged forests using allometric biomass equations developed for wood stem, cork stem, wood branch, cork branch, leaves, roots and total tree biomass based on combinations of diameter at breast height, total height and crown length as independent variables. Main results. Total tree biomass in forests was 240.58 Mg ha-1 in the young forest and 411.30 Mg ha-1 in the aged forest with a low root/shoot ratio (0.41 for young forest and 0.31 for aged forest). Total stored carbon was 419.46 Mg C ha-1 in the young forest and 658.09 Mg C ha-1 in the aged forest. Carbon stock (Mg C ha-1) was estimated to be113.61(27.08%) and 194.08 (29.49%) in trees, 3.55 (0.85%) and 5.73 (0.87%) in litter and 302.30 (72.07%) and 458.27 (69.64%) in soil in the young and aged forests, respectively. Research highlights. Aged undisturbed forest had the largest tree biomass but a lower potential for accumulation of carbon in the future; in contrast, young disturbed forest had both higher growth and carbon storage potential. (Author)

  6. Influence of Inoculation, Nitrogen and Phosphorus Levels on Wheat Growth and Soil Microbial Biomass-N Using 15N Techniques

    International Nuclear Information System (INIS)

    Galal, Y.G.; El-Ghandour, I.A.; Abdel Raouf, A.M.; Osman, M.E.

    2003-01-01

    Pot experiment was carried out with wheat that cultivated in virgin sandy soil and inoculated with Rhizobium (Rh), mycorrhizea (VAM) and mixture of both. The objective of this work was to verify the potential of these inoculum on wheat production, nutrient acquisition and microbial biomass N (MBN) contribution as affected by N and P fertilizers levels. MBN was detected through the fumigation-extraction method. Nitrogen and phosphorus fertilizers were applied at three levels, 0; 25 ppm N and 3.3 ppm P and 50 ppm N and 6.6 ppm P in the form of ( 15 NH 4 ) 2 SO 4 , 5% atom excess and super-phosphate, respectively. The effect of inoculation and chemical fertilizers on dry matter (DM), N and P uptake (shoot and grain) and MBN were traced. The obtained data revealed that the highest DM and N uptake by wheat shoot were recorded with the dual inoculation (Rh + VAM) at the highest level of N and P fertilizers. The highest grain yield was detected with single inoculum of AM fungi while N and P uptake were with dual inoculation at the same rate of fertilizers. Inoculation with Rh either alone or in combination with VAM have a positive and stimulative effect on wheat growth and N and P uptake indicating the possibilities of extending the use of symbiotic microorganisms to be applied with cereals. The fluctuation in the soil microbial biomass N did not gave a chance to recognize, exactly, the impact of inoculation and/or fertilization levels

  7. Allometric equations for estimating aboveground biomass for common shrubs in northeastern California

    Science.gov (United States)

    Steve Huff; Martin Ritchie; H. Temesgen

    2017-01-01

    Selected allometric equations and fitting strategies were evaluated for their predictive abilities for estimating above ground biomass for seven species of shrubs common to northeastern California. Size classes for woody biomass were categorized as 1-h fuels (0.1–0.6 cm), 10-h fuels (0.6–2.5 cm), 100-h fuels (2.5–7.6 cm), and 1000-h fuels (greater than 7.7 cm in...

  8. Estimates of biomass burning emissions in tropical Asia based on satellite-derived data

    OpenAIRE

    D. Chang; Y. Song

    2009-01-01

    Biomass burning in tropical Asia emits large amounts of trace gases and particulate matter into the atmosphere, which has significant implications for atmospheric chemistry and climatic change. In this study, emissions from open biomass burning over tropical Asia were evaluated during seven fire years from 2000 to 2006 (1 March 2000–31 February 2007). The size of the burned areas was estimated from newly published 1-km L3JRC and 500-m MODIS burned area products (MCD45A1). Available fuel loads...

  9. Estimation of Aboveground Biomass Using Manual Stereo Viewing of Digital Aerial Photographs in Tropical Seasonal Forest

    Directory of Open Access Journals (Sweden)

    Katsuto Shimizu

    2014-11-01

    Full Text Available The objectives of this study are to: (1 evaluate accuracy of tree height measurements of manual stereo viewing on a computer display using digital aerial photographs compared with airborne LiDAR height measurements; and (2 develop an empirical model to estimate stand-level aboveground biomass with variables derived from manual stereo viewing on the computer display in a Cambodian tropical seasonal forest. We evaluate observation error of tree height measured from the manual stereo viewing, based on field measurements. RMSEs of tree height measurement with manual stereo viewing and LiDAR were 1.96 m and 1.72 m, respectively. Then, stand-level aboveground biomass is regressed against tree height indices derived from the manual stereo viewing. We determined the best model to estimate aboveground biomass in terms of the Akaike’s information criterion. This was a model of mean tree height of the tallest five trees in each plot (R2 = 0.78; RMSE = 58.18 Mg/ha. In conclusion, manual stereo viewing on the computer display can measure tree height accurately and is useful to estimate aboveground stand biomass.

  10. Shifts in microbial populations in Rusitec fermenters as affected by the type of diet and impact of the method for estimating microbial growth (15N v. microbial DNA).

    Science.gov (United States)

    Mateos, I; Ranilla, M J; Saro, C; Carro, M D

    2017-11-01

    Rusitec fermenters are in vitro systems widely used to study ruminal fermentation, but little is known about the microbial populations establishing in them. This study was designed to assess the time evolution of microbial populations in fermenters fed medium- (MC; 50% alfalfa hay : concentrate) and high-concentrate diets (HC; 15 : 85 barley straw : concentrate). Samples from solid (SOL) and liquid (LIQ) content of fermenters were taken immediately before feeding on days 3, 8 and 14 of incubation for quantitative polymerase chain reaction and automated ribosomal intergenic spacer analysis analyses. In SOL, total bacterial DNA concentration and relative abundance of Ruminococcus flavefaciens remained unchanged over the incubation period, but protozoal DNA concentration and abundance of Fibrobacter succinogenes, Ruminococcus albus and fungi decreased and abundance of methanogenic archaea increased. In LIQ, total bacterial DNA concentration increased with time, whereas concentration of protozoal DNA and abundance of methanogens and fungi decreased. Diet×time interactions were observed for bacterial and protozoal DNA and relative abundance of F. succinogenes and R. albus in SOL, as well as for protozoal DNA in LIQ. Bacterial diversity in SOL increased with time, but no changes were observed in LIQ. The incubated diet influenced all microbial populations, with the exception of total bacteria and fungi abundance in LIQ. Bacterial diversity was higher in MC-fed than in HC-fed fermenters in SOL, but no differences were detected in LIQ. Values of pH, daily production of volatile fatty acids and CH4 and isobutyrate proportions remained stable over the incubation period, but other fermentation parameters varied with time. The relationships among microbial populations and fermentation parameters were in well agreement with those previously reported in in vivo studies. Using 15N as a microbial marker or quantifying total microbial DNA for estimating microbial protein synthesis

  11. Effects of model choice and forest structure on inventory-based estimations of Puerto Rican forest biomass

    Science.gov (United States)

    Thomas J. Brandeis; Maria Del Rocio; Suarez Rozo

    2005-01-01

    Total aboveground live tree biomass in Puerto Rican lower montane wet, subtropical wet, subtropical moist and subtropical dry forests was estimated using data from two forest inventories and published regression equations. Multiple potentially-applicable published biomass models existed for some forested life zones, and their estimates tended to diverge with increasing...

  12. A Simultaneous Density-Integral System for Estimating Stem Profile and Biomass: Slash Pine and Willow Oak

    Science.gov (United States)

    Bernard R. Parresol; Charles E. Thomas

    1996-01-01

    In the wood utilization industry, both stem profile and biomass are important quantities. The two have traditionally been estimated separately. The introduction of a density-integral method allows for coincident estimation of stem profile and biomass, based on the calculus of mass theory, and provides an alternative to weight-ratio methodology. In the initial...

  13. Dry season biomass estimation as an indicator of rangeland quantity using multi-scale remote sensing data

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2014-10-01

    Full Text Available vegetation is green and photosynthetic active. During dry season, biomass estimation is always not plausible using vegetation indices. The aim of this study is to estimate dry biomass using the multi-scale remote sensing data in the savanna ecosystem. Field...

  14. Effect of incorporation of walnut cake (Juglans regia in concentrate mixture on degradation of dry matter, organic matter and production of microbial biomass in vitro in goat

    Directory of Open Access Journals (Sweden)

    Mohsin Ahmad Mir

    2015-10-01

    Full Text Available Aim: This study was carried out to investigate the effect of incorporation of different level of walnut cake in concentrate mixture on in vitro dry matter degradation in order to determine its level of supplementation in ruminant ration. Materials and Methods: Walnut cake was used @ 0, 10, 15, 20, 25 and 30% level to formulate an iso-nitrogenous concentrate mixtures and designated as T1, T2, T3, T4, T5 and T6 respectively. The different formulae of concentrate mixtures were used for in vitro gas production studies using goat rumen liquor with wheat straw in 40:60 ratio. Proximate composition, fiber fractionation and calcium and phosphrous content of walnut cake were estimated. Result: The per cent IVDMD value of T1 and T2 diets was 68.42 ± 1.20 and 67.25 ± 1.37 respectively which was found highest (P<0.05 T3, T4, T5 and T6. Similar trend was also found for TDOM and MBP. Inclusion of walnut cake at 10% level in the concentrate mixture does not affect in vitro dry matter digestibility (IVDMD, truly degradable organic matter (TDOM, mg/200 mg DM, total gas production, microbial biomass production (MBP and efficiency of microbial biomass production (EMP. Conclusion: It is concluded that walnut cake incorporation up to 10% level in the iso -nitrogenous concentrate mixture has no any negative effect on in vitro digestibility of dry matter (DM, TDOM, MBP, EMP and total gas production in goat.

  15. Effects of Hurricane-Felled Tree Trunks on Soil Carbon, Nitrogen, Microbial Biomass, and Root Length in a Wet Tropical Forest

    Directory of Open Access Journals (Sweden)

    D. Jean Lodge

    2016-11-01

    Full Text Available Decaying coarse woody debris can affect the underlying soil either by augmenting nutrients that can be exploited by tree roots, or by diminishing nutrient availability through stimulation of microbial nutrient immobilization. We analyzed C, N, microbial biomass C and root length in closely paired soil samples taken under versus 20–50 cm away from large trunks of two species felled by Hugo (1989 and Georges (1998 three times during wet and dry seasons over the two years following the study conducted by Georges. Soil microbial biomass, % C and % N were significantly higher under than away from logs felled by both hurricanes (i.e., 1989 and 1998, at all sampling times and at both depths (0–10 and 10–20 cm. Frass from wood boring beetles may contribute to early effects. Root length was greater away from logs during the dry season, and under logs in the wet season. Root length was correlated with microbial biomass C, soil N and soil moisture (R = 0.36, 0.18, and 0.27, respectively; all p values < 0.05. Microbial biomass C varied significantly among seasons but differences between positions (under vs. away were only suggestive. Microbial C was correlated with soil N (R = 0.35. Surface soil on the upslope side of the logs had significantly more N and microbial biomass, likely from accumulation of leaf litter above the logs on steep slopes. We conclude that decaying wood can provide ephemeral resources that are exploited by tree roots during some seasons.

  16. Evaluation of Sentinel-1A Data For Above Ground Biomass Estimation in Different Forests in India

    Science.gov (United States)

    Vadrevu, Krishna Prasad

    2017-01-01

    Use of remote sensing data for mapping and monitoring of forest biomass across large spatial scales can aid in addressing uncertainties in carbon cycle. Earlier, several researchers reported on the use of Synthetic Aperture Radar (SAR) data for characterizing forest structural parameters and the above ground biomass estimation. However, these studies cannot be generalized and the algorithms cannot be applied to all types of forests without additional information on the forest physiognomy, stand structure and biomass characteristics. The radar backscatter signal also saturates as forest parameters such as biomass and the tree height increase. It is also not clear how different polarizations (VV versus VH) impact the backscatter retrievals in different forested regions. Thus, it is important to evaluate the potential of SAR data in different landscapes for characterizing forest structural parameters. In this study, the SAR data from Sentinel-1A has been used to characterize forest structural parameters including the above ground biomass from tropical forests of India. Ground based data on tree density, basal area and above ground biomass data from thirty-eight different forested sites has been collected to relate to SAR data. After the pre-processing of Sentinel 1-A data for radiometric calibration, geo-correction, terrain correction and speckle filtering, the variability in the backscatter signal in relation tree density, basal area and above biomass density has been investigated. Results from the curve fitting approach suggested exponential model between the Sentinel-1A backscatter versus tree density and above ground biomass whereas the relationship was almost linear with the basal area in the VV polarization mode. Of the different parameters, tree density could explain most of the variations in backscatter. Both VV and VH backscatter signals could explain only thirty and thirty three percent of variation in above biomass in different forest sites of India

  17. Importance of tree basic density in biomass estimation and associated uncertainties

    DEFF Research Database (Denmark)

    Njana, Marco Andrew; Meilby, Henrik; Eid, Tron

    2016-01-01

    Key message Aboveground and belowground tree basic densities varied between and within the three mangrove species. If appropriately determined and applied, basic density may be useful in estimation of tree biomass. Predictive accuracy of the common (i.e. multi-species) models including aboveground...... of sustainable forest management, conservation and enhancement of carbon stocks (REDD+) initiatives offer an opportunity for sustainable management of forests including mangroves. In carbon accounting for REDD+, it is required that carbon estimates prepared for monitoring reporting and verification schemes...... and examine uncertainties in estimation of tree biomass using indirect methods. Methods This study focused on three dominant mangrove species (Avicennia marina (Forssk.) Vierh, Sonneratia alba J. Smith and Rhizophora mucronata Lam.) in Tanzania. A total of 120 trees were destructively sampled for aboveground...

  18. Propagation of measurement accuracy to biomass soft-sensor estimation and control quality.

    Science.gov (United States)

    Steinwandter, Valentin; Zahel, Thomas; Sagmeister, Patrick; Herwig, Christoph

    2017-01-01

    In biopharmaceutical process development and manufacturing, the online measurement of biomass and derived specific turnover rates is a central task to physiologically monitor and control the process. However, hard-type sensors such as dielectric spectroscopy, broth fluorescence, or permittivity measurement harbor various disadvantages. Therefore, soft-sensors, which use measurements of the off-gas stream and substrate feed to reconcile turnover rates and provide an online estimate of the biomass formation, are smart alternatives. For the reconciliation procedure, mass and energy balances are used together with accuracy estimations of measured conversion rates, which were so far arbitrarily chosen and static over the entire process. In this contribution, we present a novel strategy within the soft-sensor framework (named adaptive soft-sensor) to propagate uncertainties from measurements to conversion rates and demonstrate the benefits: For industrially relevant conditions, hereby the error of the resulting estimated biomass formation rate and specific substrate consumption rate could be decreased by 43 and 64 %, respectively, compared to traditional soft-sensor approaches. Moreover, we present a generic workflow to determine the required raw signal accuracy to obtain predefined accuracies of soft-sensor estimations. Thereby, appropriate measurement devices and maintenance intervals can be selected. Furthermore, using this workflow, we demonstrate that the estimation accuracy of the soft-sensor can be additionally and substantially increased.

  19. Effects of Nitrogen and Water on Soil Enzyme Activity and Soil Microbial Biomass in Stipa baicalensis Steppe,Inner Mongolia of North China

    Directory of Open Access Journals (Sweden)

    WANG Jie

    2014-06-01

    Full Text Available In this paper, eight nitrogen treatments were applied at 0 g·m -2(N0, 1.5 g·m -2(N15, 3.0 g·m -2(N30, 5.0 g·m -2(N50, 10.0 g·m -2(N100, 15.0 g·m -2(N150, 20.0 g·m -2(N200, 30.0 g·m -2(N300 as NH 4 NO 3 and adding water to simulate summer rainfall of 100 mm, the interactive experiment was set to explore the effects of nitrogen and water addition in Stipa baicalensis steppe on soil nutrients, enzyme activities and soil microbial biomass. The results showed that the nitrogen and water addition changed soil physico-chemical factors obviously, the content of soil total organic carbon, total nitrogen, nitrate nitrogen and ammonium nitrogen increased along with the increasing of application rate of nitrogen, on the contrary, the soil pH value had decreasing trend. Appropriate application of nitrogen could enhance the activity of urease and catalase but decreased the activity of polyphenol oxidase. Nitrogen and water addition had significant effect on soil microbial biomass C and N. Higher level of N fertilizer significantly reduced microbial biomass C, and the microbial biomass N was on the rise with the application rate of nitrogen. The addition of water could slow the inhibition of nitrogen to microorganism and increase the microbial biomass C and N. A closed relationship existed in soil nutrient, activities of soil enzyme and soil microbial biomass C and N. The significantly positive correlation existed between total N, organic C, nitrate N and catalase, significantly negative correlation between nitrate N, ammonium N, total N and polyphenol oxidase. Microbial biomass N was significantly positive correlated with total N, nitrate N, ammonium N, catalase, phosphatase, and was negative correlated with polyphenol oxidase. Microbial biomass C was significantly positive correlated with polyphenol oxidase, and was negative correlated with catalase.

  20. Biomass estimation with high resolution satellite images: A case study of Quercus rotundifolia

    Science.gov (United States)

    Sousa, Adélia M. O.; Gonçalves, Ana Cristina; Mesquita, Paulo; Marques da Silva, José R.

    2015-03-01

    Forest biomass has had a growing importance in the world economy as a global strategic reserve, due to applications in bioenergy, bioproduct development and issues related to reducing greenhouse gas emissions. Current techniques used for forest inventory are usually time consuming and expensive. Thus, there is an urgent need to develop reliable, low cost methods that can be used for forest biomass estimation and monitoring. This study uses new techniques to process high spatial resolution satellite images (0.70 m) in order to assess and monitor forest biomass. Multi-resolution segmentation method and object oriented classification are used to obtain the area of tree canopy horizontal projection for Quercus rotundifolia. Forest inventory allows for calculation of tree and canopy horizontal projection and biomass, the latter with allometric functions. The two data sets are used to develop linear functions to assess above ground biomass, with crown horizontal projection as an independent variable. The functions for the cumulative values, both for inventory and satellite data, for a prediction error equal or smaller than the Portuguese national forest inventory (7%), correspond to stand areas of 0.5 ha, which include most of the Q.rotundifolia stands.

  1. Are variations in heterotrophic soil respiration related to changes in substrate availability and microbial biomass carbon in the subtropical forests?

    Science.gov (United States)

    Wei, Hui; Chen, Xiaomei; Xiao, Guoliang; Guenet, Bertrand; Vicca, Sara; Shen, Weijun

    2015-12-16

    Soil temperature and moisture are widely-recognized controlling factors on heterotrophic soil respiration (Rh), although they often explain only a portion of Rh variability. How other soil physicochemical and microbial properties may contribute to Rh variability has been less studied. We conducted field measurements on Rh half-monthly and associated soil properties monthly for two years in four subtropical forests of southern China to assess influences of carbon availability and microbial properties on Rh. Rh in coniferous forest was significantly lower than that in the other three broadleaf species-dominated forests and exhibited obvious seasonal variations in the four forests (P forests. The quantity and decomposability of dissolved organic carbon (DOC) were significantly important to Rh variations, but the effect of DOC content on Rh was confounded with temperature, as revealed by partial mantel test. Microbial biomass carbon (MBC) was significantly related to Rh variations across forests during the warm season (P = 0.043). Our results suggest that DOC and MBC may be important when predicting Rh under some conditions, and highlight the complexity by mutual effects of them with environmental factors on Rh variations.

  2. The Influence of Tallow on Rumen Metabolism, Microbial Biomass Synthesis and Fatty Acid Composition of Bacteria and Protozoa

    DEFF Research Database (Denmark)

    Weisbjerg, Martin Riis; Børsting, Christian Friis; Hvelplund, Torben

    1992-01-01

    Rumen metabolism, microbial biomass synthesis and microbial long chain fatty acid composition were studied in lactating cows fed at two levels of dry matter intake (L, 8.6 kg DM and H, 12.6 kg DM) with 0, 4 and 6% added tallow at the low feed level (L0, L4 and L6) and 0, 2, 4 and 6% at the high...... feed level (H0, H2, H4 and H6). Fibre digestibility was not significantly affected by tallow addition. Increasing tallow level in the diet decreased the total VFA concentration, the ratio of acetic acid to propionic acid and the ammonia concentration in the rumen. Crude fat and fatty acid content...... in bacterial and protozoal dry matter increased with increased tallow level, especially due to an increase in fatty acids originating from the feeds. Microbial synthesis in the rumen and flow of amino acids to the duodenum was highest for medium fat intake at the high feed level....

  3. Are variations in heterotrophic soil respiration related to changes in substrate availability and microbial biomass carbon in the subtropical forests?

    Science.gov (United States)

    Wei, Hui; Chen, Xiaomei; Xiao, Guoliang; Guenet, Bertrand; Vicca, Sara; Shen, Weijun

    2015-01-01

    Soil temperature and moisture are widely-recognized controlling factors on heterotrophic soil respiration (Rh), although they often explain only a portion of Rh variability. How other soil physicochemical and microbial properties may contribute to Rh variability has been less studied. We conducted field measurements on Rh half-monthly and associated soil properties monthly for two years in four subtropical forests of southern China to assess influences of carbon availability and microbial properties on Rh. Rh in coniferous forest was significantly lower than that in the other three broadleaf species-dominated forests and exhibited obvious seasonal variations in the four forests (P < 0.05). Temperature was the primary factor influencing the seasonal variability of Rh while moisture was not in these humid subtropical forests. The quantity and decomposability of dissolved organic carbon (DOC) were significantly important to Rh variations, but the effect of DOC content on Rh was confounded with temperature, as revealed by partial mantel test. Microbial biomass carbon (MBC) was significantly related to Rh variations across forests during the warm season (P = 0.043). Our results suggest that DOC and MBC may be important when predicting Rh under some conditions, and highlight the complexity by mutual effects of them with environmental factors on Rh variations. PMID:26670822

  4. Precise plant height monitoring and biomass estimation with Terrestrial Laser Scanning in paddy rice

    Directory of Open Access Journals (Sweden)

    N. Tilly

    2013-10-01

    Full Text Available Optimizing crop management is a major topic in the field of precision agriculture as the growing world population puts pressure on the efficiency of field production. Accordingly, methods to measure plant parameters with the needed precision and within-field resolution are required. Studies show that Terrestrial Laser Scanning (TLS is a suitable method to capture small objects like crop plants. In this contribution, the results of multi-temporal surveys on paddy rice fields with the TLS system Riegl LMS-Z420i are presented. Three campaigns were carried out during the key vegetative stage of rice plants in the growing period 2012 to monitor the plant height. The TLS-derived point clouds are interpolated to visualize plant height above ground as crop surface models (CSMs with a high resolution of 0.01 m. Spatio-temporal differences within the data of one campaign and between consecutive campaigns can be detected. The results were validated against manually measured plant heights with a high correlation (R2 = 0.71. Furthermore, the dependence of actual biomass from plant height was evaluated. To the present, no method for the non-destructive determination of biomass is found yet. Thus, plant parameters, like the height, have to be used for biomass estimations. The good correlation (R2 = 0.66 leads to the assumption that biomass can be estimated from plant height measurements. The results show that TLS can be considered as a very promising tool for precision agriculture.

  5. Relative contributions of sampling effort, measuring, and weighing to precision of larval sea lamprey biomass estimates

    Science.gov (United States)

    Slade, Jeffrey W.; Adams, Jean V.; Cuddy, Douglas W.; Neave, Fraser B.; Sullivan, W. Paul; Young, Robert J.; Fodale, Michael F.; Jones, Michael L.

    2003-01-01

    We developed two weight-length models from 231 populations of larval sea lampreys (Petromyzon marinus) collected from tributaries of the Great Lakes: Lake Ontario (21), Lake Erie (6), Lake Huron (67), Lake Michigan (76), and Lake Superior (61). Both models were mixed models, which used population as a random effect and additional environmental factors as fixed effects. We resampled weights and lengths 1,000 times from data collected in each of 14 other populations not used to develop the models, obtaining a weight and length distribution from reach resampling. To test model performance, we applied the two weight-length models to the resampled length distributions and calculated the predicted mean weights. We also calculated the observed mean weight for each resampling and for each of the original 14 data sets. When the average of predicted means was compared to means from the original data in each stream, inclusion of environmental factors did not consistently improve the performance of the weight-length model. We estimated the variance associated with measures of abundance and mean weight for each of the 14 selected populations and determined that a conservative estimate of the proportional contribution to variance associated with estimating abundance accounted for 32% to 95% of the variance (mean = 66%). Variability in the biomass estimate appears more affected by variability in estimating abundance than in converting length to weight. Hence, efforts to improve the precision of biomass estimates would be aided most by reducing the variability associated with estimating abundance.

  6. Impact of phenazine-1-carboxylic acid upon iron speciation and microbial biomass in the rhizosphere of wheat

    Science.gov (United States)

    LeTourneau, M.; Marshall, M.; Grant, M.; Freeze, P.; Cliff, J. B.; Lai, B.; Strawn, D. G.; Thomashow, L. S.; Weller, D. M.; Harsh, J. B.

    2015-12-01

    Phenazine-1-carboxylic acid (PCA) is a redox-active antibiotic produced by diverse bacterial taxa, and has been shown to facilitate interactions between biofilms and iron (hydr)oxides in culture systems (Wang et al. 2011, J Bacteriol 192: 365). Because rhizobacterial biofilms are a major sink for plant-derived carbon and source for soil organic matter (SOM), and Fe (hydr)oxides have reactive surfaces that influence the stability of microbial biomass and SOM, PCA-producing rhizobacteria could influence soil carbon fluxes. Large populations of Pseudomonas fluorescens strains producing PCA in concentrations up to 1 μg/g root have been observed in the rhizosphere of non-irrigated wheat fields covering 1.56 million hectares of central Washington state. This is one of the highest concentrations ever reported for a natural antibiotic in a terrestrial ecosystem (Mavrodi et al. 2012, Appl Environ Microb 78: 804). Microscopic comparisons of PCA-producing (PCA+) and non-PCA-producing (PCA-) rhizobacterial colony morphologies, and comparisons of Fe extractions from rhizosphere soil inoculated with PCA+ and PCA- strains suggest that PCA promotes biofilm development as well as dramatic Fe transformations throughout the rhizosphere (unpublished data). In order to illustrate PCA-mediated interactions between biofilms and Fe (hydr)oxides in the rhizosphere, identify the specific Fe phases favored by PCA, and establish the ramifications for stability and distribution of microbial biomass and SOM, we have collected electron micrographs, X-ray fluorescence images, X-ray absorption near-edge spectra, and secondary-ion mass spectrometry images of wheat root sections inoculated with 15N-labelled PCA+ or PCA- rhizobacteria. These images and spectra allow us to assess the accumulation, turnover, and distribution of microbial biomass, the associations between Fe and other nutrients such as phosphorus, and the redox status and speciation of iron in the presence and absence of PCA. This

  7. Combining Lidar and Synthetic Aperture Radar Data to Estimate Forest Biomass: Status and Prospects

    Directory of Open Access Journals (Sweden)

    Sanna Kaasalainen

    2015-01-01

    Full Text Available Research activities combining lidar and radar remote sensing have increased in recent years. The main focus in combining lidar-radar forest remote sensing has been on the retrieval of the aboveground biomass (AGB, which is a primary variable related to carbon cycle in land ecosystems, and has therefore been identified as an essential climate variable. In this review, we summarize the studies combining lidar and radar in estimating forest AGB. We discuss the complementary use of lidar and radar according to the relevance of the added value. The most promising prospects for combining lidar and radar data are in the use of lidar-derived ground elevations for improving large-area biomass estimates from radar, and in upscaling of lidar-based AGB data across large areas covered by spaceborne radar missions.

  8. Plot size recommendations for biomass estimation in a midwestern old-growth forest

    Science.gov (United States)

    Martin A. Spetich; George R Parker

    1998-01-01

    The authors examine the relationship between disturbance regime and plot size for woody biomass estimation in a midwestern old-growth deciduous forest from 1926 to 1992. Analysis was done on the core 19.6 ac of a 50.1 ac forest in which every tree 4 in. d.b.h. and greater has been tagged and mapped since 1926. Five windows of time are compared—1926, 1976, 1981, 1986...

  9. Contrasting effects of ammonium and nitrate additions on the biomass of soil microbial communities and enzyme activities in subtropical China

    Directory of Open Access Journals (Sweden)

    C. Zhang

    2017-10-01

    Full Text Available The nitrate to ammonium ratios in nitrogen (N compounds in wet atmospheric deposits have increased over the recent past, which is a cause for some concern as the individual effects of nitrate and ammonium deposition on the biomass of different soil microbial communities and enzyme activities are still poorly defined. We established a field experiment and applied ammonium (NH4Cl and nitrate (NaNO3 at monthly intervals over a period of 4 years. We collected soil samples from the ammonium and nitrate treatments and control plots in three different seasons, namely spring, summer, and fall, to evaluate the how the biomass of different soil microbial communities and enzyme activities responded to the ammonium (NH4Cl and nitrate (NaNO3 applications. Our results showed that the total contents of phospholipid fatty acids (PLFAs decreased by 24 and 11 % in the ammonium and nitrate treatments, respectively. The inhibitory effects of ammonium on Gram-positive bacteria (G+ and bacteria, fungi, actinomycetes, and arbuscular mycorrhizal fungi (AMF PLFA contents ranged from 14 to 40 % across the three seasons. We also observed that the absolute activities of C, N, and P hydrolyses and oxidases were inhibited by ammonium and nitrate, but that nitrate had stronger inhibitory effects on the activities of acid phosphatase (AP than ammonium. The activities of N-acquisition specific enzymes (enzyme activities normalized by total PLFA contents were about 21 and 43 % lower in the ammonium and nitrate treatments than in the control, respectively. However, the activities of P-acquisition specific enzymes were about 19 % higher in the ammonium treatment than in the control. Using redundancy analysis (RDA, we found that the measured C, N, and P hydrolysis and polyphenol oxidase (PPO activities were positively correlated with the soil pH and ammonium contents, but were negatively correlated with the nitrate contents. The PLFA biomarker contents were positively

  10. Contrasting effects of ammonium and nitrate additions on the biomass of soil microbial communities and enzyme activities in subtropical China

    Science.gov (United States)

    Zhang, Chuang; Zhang, Xin-Yu; Zou, Hong-Tao; Kou, Liang; Yang, Yang; Wen, Xue-Fa; Li, Sheng-Gong; Wang, Hui-Min; Sun, Xiao-Min

    2017-10-01

    The nitrate to ammonium ratios in nitrogen (N) compounds in wet atmospheric deposits have increased over the recent past, which is a cause for some concern as the individual effects of nitrate and ammonium deposition on the biomass of different soil microbial communities and enzyme activities are still poorly defined. We established a field experiment and applied ammonium (NH4Cl) and nitrate (NaNO3) at monthly intervals over a period of 4 years. We collected soil samples from the ammonium and nitrate treatments and control plots in three different seasons, namely spring, summer, and fall, to evaluate the how the biomass of different soil microbial communities and enzyme activities responded to the ammonium (NH4Cl) and nitrate (NaNO3) applications. Our results showed that the total contents of phospholipid fatty acids (PLFAs) decreased by 24 and 11 % in the ammonium and nitrate treatments, respectively. The inhibitory effects of ammonium on Gram-positive bacteria (G+) and bacteria, fungi, actinomycetes, and arbuscular mycorrhizal fungi (AMF) PLFA contents ranged from 14 to 40 % across the three seasons. We also observed that the absolute activities of C, N, and P hydrolyses and oxidases were inhibited by ammonium and nitrate, but that nitrate had stronger inhibitory effects on the activities of acid phosphatase (AP) than ammonium. The activities of N-acquisition specific enzymes (enzyme activities normalized by total PLFA contents) were about 21 and 43 % lower in the ammonium and nitrate treatments than in the control, respectively. However, the activities of P-acquisition specific enzymes were about 19 % higher in the ammonium treatment than in the control. Using redundancy analysis (RDA), we found that the measured C, N, and P hydrolysis and polyphenol oxidase (PPO) activities were positively correlated with the soil pH and ammonium contents, but were negatively correlated with the nitrate contents. The PLFA biomarker contents were positively correlated with soil

  11. Characterization of three plant biomass-degrading microbial consortia by metagenomics- and metasecretomics-based approaches

    DEFF Research Database (Denmark)

    Jiménez, Diego Javier; Brossi, Maria Julia de Lima; Schückel, Julia

    2016-01-01

    ). The highest degradation rates of lignin (~59 %) were observed with SG-M, whereas CS-M showed a high consumption of cellulose and hemicellulose. Analyses of the carbohydrate-active enzymes in the three microbial consortia showed the dominance of glycosyl hydrolases (e.g. of families GH3, GH43, GH13, GH10, GH29......), switchgrass (SG-M) and corn stover (CS-M) under aerobic and mesophilic conditions. Molecular fingerprintings, bacterial 16S ribosomal RNA (rRNA) gene amplicon sequencing and metagenomic analyses showed that the three microbial consortia were taxonomically distinct. Based on the taxonomic affiliation...

  12. Microbial correlates of Fusarium biomass and deoxynivalenol content in individual wheat seeds

    Science.gov (United States)

    Manipulating the microbiome of wheat seeds and heads may contribute to control of Fusarium head blight and mycotoxin accumulation in grain, which creates a food safety hazard. With the aim of identifying novel management targets, we looked for correlations between Fusarium biomass or deoxynivalenol ...

  13. Microbial biodiesel production from oil palm biomass hydrolysate using marine Rhodococcus sp. YHY01.

    Science.gov (United States)

    Bhatia, Shashi Kant; Kim, Junyoung; Song, Hun-Seok; Kim, Hyun Joong; Jeon, Jong-Min; Sathiyanarayanan, Ganesan; Yoon, Jeong-Jun; Park, Kyungmoon; Kim, Yun-Gon; Yang, Yung-Hun

    2017-06-01

    The effect of various biomass derived inhibitors (i.e. furfural, hydroxymethylfurfural (HMF), vanillin, 4-hydroxy benzaldehyde (4-HB) and acetate) was investigated for fatty acid accumulation in Rhodococcus sp. YHY 01. Rhodococcus sp. YHY01 was able to utilize acetate, vanillin, and 4-HB for biomass production and fatty acid accumulation. The IC 50 value for furfural (3.1mM), HMF (3.2mM), vanillin (2.0mM), 4-HB (2.7mM) and acetate (3.7mM) was calculated. HMF and vanillin affect fatty acid composition and increase saturated fatty acid content. Rhodococcus sp. YHY 01 cultured with empty fruit bunch hydrolysate (EFBH) as the main carbon source resulted in enhanced biomass (20%) and fatty acid productivity (37%), in compression to glucose as a carbon source. Overall, this study showed the beneficial effects of inhibitory molecules on growth and fatty acid production, and support the idea of biomass hydrolysate utilization for biodiesel production by avoiding complex efforts to remove inhibitory compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Colloid-based multiplexed method for screening plant biomass-degrading glycoside hydrolase activities in microbial communities

    Energy Technology Data Exchange (ETDEWEB)

    Reindl, W.; Deng, K.; Gladden, J.M.; Cheng, G.; Wong, A.; Singer, S.W.; Singh, S.; Lee, J.-C.; Yao, J.-S.; Hazen, T.C.; Singh, A.K; Simmons, B.A.; Adams, P.D.; Northen, T.R.

    2011-05-01

    The enzymatic hydrolysis of long-chain polysaccharides is a crucial step in the conversion of biomass to lignocellulosic biofuels. The identification and characterization of optimal glycoside hydrolases is dependent on enzyme activity assays, however existing methods are limited in terms of compatibility with a broad range of reaction conditions, sample complexity, and especially multiplexity. The method we present is a multiplexed approach based on Nanostructure-Initiator Mass Spectrometry (NIMS) that allowed studying several glycolytic activities in parallel under diverse assay conditions. Although the substrate analogs carried a highly hydrophobic perfluorinated tag, assays could be performed in aqueous solutions due colloid formation of the substrate molecules. We first validated our method by analyzing known {beta}-glucosidase and {beta}-xylosidase activities in single and parallel assay setups, followed by the identification and characterization of yet unknown glycoside hydrolase activities in microbial communities.

  15. Influence of mechanical disintegration on the microbial growth of aerobic sludge biomass: A comparative study of ultrasonic and shear gap homogenizers by oxygen uptake measurements.

    Science.gov (United States)

    Divyalakshmi, P; Murugan, D; Sivarajan, M; Saravanan, P; Lajapathi Rai, C

    2015-11-01

    Wastewater treatment plant incorporates physical, chemical and biological processes to treat and remove the contaminants. The main drawback of conventional activated sludge process is the huge production of excess sludge, which is an unavoidable byproduct. The treatment and disposal of excess sludge costs about 60% of the total operating cost. The ideal way to reduce excess sludge production during wastewater treatment is by preventing biomass formation within the aerobic treatment train rather than post treatment of the generated sludge. In the present investigation two different mechanical devices namely, Ultrasonic and Shear Gap homogenizers have been employed to disintegrate the aerobic biomass. This study is intended to restrict the multiplication of microbial biomass and at the same time degrade the organics present in wastewater by increasing the oxidative capacity of microorganisms. The disintegrability on biomass was determined by biochemical methods. Degree of inactivation provides the information on inability of microorganisms to consume oxygen upon disruption. The soluble COD quantifies the extent of release of intra cellular compounds. The participation of disintegrated microorganism in wastewater treatment process was carried out in two identical respirometeric reactors. The results show that Ultrasonic homogenizer is very effective in the disruption of microorganisms leading to a maximum microbial growth reduction of 27%. On the other hand, Shear gap homogenizer does not favor the sludge growth reduction rather it facilitates the growth. This study also shows that for better microbial growth reduction, floc size reduction alone is not sufficient but also microbial disruption is essential. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Response of the soil microbial community and soil nutrient bioavailability to biomass harvesting and reserve tree retention in northern Minnesota aspen-dominated forests

    Science.gov (United States)

    Tera E. Lewandowski; Jodi A. Forrester; David J. Mladenoff; Anthony W. D' Amato; Brian J. Palik

    2016-01-01

    Intensive forest biomass harvesting, or the removal of harvesting slash (woody debris from tree branches and tops) for use as biofuel, has the potential to negatively affect the soil microbial community (SMC) due to loss of carbon and nutrient inputs from the slash, alteration of the soil microclimate, and increased nutrient leaching. These effects could result in...

  17. Potential of ALOS2 and NDVI to Estimate Forest Above-Ground Biomass, and Comparison with Lidar-Derived Estimates

    Directory of Open Access Journals (Sweden)

    Gaia Vaglio Laurin

    2016-12-01

    Full Text Available Remote sensing supports carbon estimation, allowing the upscaling of field measurements to large extents. Lidar is considered the premier instrument to estimate above ground biomass, but data are expensive and collected on-demand, with limited spatial and temporal coverage. The previous JERS and ALOS SAR satellites data were extensively employed to model forest biomass, with literature suggesting signal saturation at low-moderate biomass values, and an influence of plot size on estimates accuracy. The ALOS2 continuity mission since May 2014 produces data with improved features with respect to the former ALOS, such as increased spatial resolution and reduced revisit time. We used ALOS2 backscatter data, testing also the integration with additional features (SAR textures and NDVI from Landsat 8 data together with ground truth, to model and map above ground biomass in two mixed forest sites: Tahoe (California and Asiago (Alps. While texture was useful to improve the model performance, the best model was obtained using joined SAR and NDVI (R2 equal to 0.66. In this model, only a slight saturation was observed, at higher levels than what usually reported in literature for SAR; the trend requires further investigation but the model confirmed the complementarity of optical and SAR datatypes. For comparison purposes, we also generated a biomass map for Asiago using lidar data, and considered a previous lidar-based study for Tahoe; in these areas, the observed R2 were 0.92 for Tahoe and 0.75 for Asiago, respectively. The quantitative comparison of the carbon stocks obtained with the two methods allows discussion of sensor suitability. The range of local variation captured by lidar is higher than those by SAR and NDVI, with the latter showing overestimation. However, this overestimation is very limited for one of the study areas, suggesting that when the purpose is the overall quantification of the stored carbon, especially in areas with high carbon

  18. Microbial biomass and necromass turnover times in the contrasting seafloor settings

    DEFF Research Database (Denmark)

    Mhatre, Snehit

    2017-01-01

    in the deep biosphere microbial community. His work therefore opens a new avenue in exploring the possible mechanisms involved in facilitating the long-term survival of microorganisms under energy-deprived conditions. The PhD degree was completed at the Center for Geomicrobiology, department of Bioscience...

  19. RESPONSE OF SOIL MICROBIAL BIOMASS AND COMMUNITY COMPOSITION TO CHRONIC NITROGEN ADDITIONS AT HARVARD FOREST

    Science.gov (United States)

    Soil microbial communities may respond to anthropogenic increases in ecosystem nitrogen (N) availability, and their response may ultimately feedback on ecosystem carbon and N dynamics. We examined the long-term effects of chronic N additions on soil microbes by measuring soil mi...

  20. Effects of titanium dioxide nanoparticles on soil microbial communities and wheat biomass

    NARCIS (Netherlands)

    Moll, Janine; Klingenfuss, Florian; Widmer, Franco; Gogos, Alexander; Bucheli, Thomas D.; Hartmann, Martin; van der Heijden, Marcel G.A.

    2017-01-01

    Titanium dioxide nanoparticles (TiO2 NPs) are the most produced NPs worldwide and have great potential to be utilized in agriculture as additives for plant protection products. However, concerns have been raised that some NPs may negatively affect crops and soil microbial communities, including

  1. Abundance, production and stabilization of microbial biomass under conventional and reduced tillage

    NARCIS (Netherlands)

    Groenigen, van K.J.; Bloem, J.; Baath, E.; Boeckx, P.; Rousk, J.; Bodé, S.; Forristal, P.D.; Jones, M.B.

    2010-01-01

    Soil tillage practices affect the soil microbial community in various ways, with possible consequences for nitrogen (N) losses, plant growth and soil organic carbon (C) sequestration. As microbes affect soil organic matter (SOM) dynamics largely through their activity, their impact may not be

  2. Seasonal and interannual dynamics of soil microbial biomass and available nitrogen in an alpine meadow in the eastern part of Qinghai-Tibet Plateau, China

    Science.gov (United States)

    Xu, Bo; Wang, Jinniu; Wu, Ning; Wu, Yan; Shi, Fusun

    2018-01-01

    Soil microbial activity varies seasonally in frozen alpine soils during cold seasons and plays a crucial role in available N pool accumulation in soil. The intra- and interannual patterns of microbial and nutrient dynamics reflect the influences of changing weather factors, and thus provide important insights into the biogeochemical cycles and ecological functions of ecosystems. We documented the seasonal and interannual dynamics of soil microbial and available N in an alpine meadow in the eastern part of Qinghai-Tibet Plateau, China, between April 2011 and October 2013. Soil was collected in the middle of each month and analyzed for water content, microbial biomass C (MBC) and N (MBN), dissolved organic C and N, and inorganic N. Soil microbial community composition was measured by the dilution-plate method. Fungi and actinomycetes dominated the microbial community during the nongrowing seasons, and the proportion of bacteria increased considerably during the early growing seasons. Trends of consistently increasing MBC and available N pools were observed during the nongrowing seasons. MBC sharply declined during soil thaw and was accompanied by a peak in available N pool. Induced by changes in soil temperatures, significant shifts in the structures and functions of microbial communities were observed during the winter-spring transition and largely contributed to microbial reduction. The divergent seasonal dynamics of different N forms showed a complementary nutrient supply pattern during the growing season. Similarities between the interannual dynamics of microbial biomass and available N pools were observed, and soil temperature and water conditions were the primary environmental factors driving interannual fluctuations. Owing to the changes in climate, seasonal soil microbial activities and nutrient supply patterns are expected to change further, and these changes may have crucial implications for the productivity and biodiversity of alpine ecosystems.

  3. Dynamics of soil organic carbon and microbial biomass carbon in relation to water erosion and tillage erosion.

    Science.gov (United States)

    Xiaojun, Nie; Jianhui, Zhang; Zhengan, Su

    2013-01-01

    Dynamics of soil organic carbon (SOC) are associated with soil erosion, yet there is a shortage of research concerning the relationship between soil erosion, SOC, and especially microbial biomass carbon (MBC). In this paper, we selected two typical slope landscapes including gentle and steep slopes from the Sichuan Basin, China, and used the (137)Cs technique to determine the effects of water erosion and tillage erosion on the dynamics of SOC and MBC. Soil samples for the determination of (137)Cs, SOC, MBC and soil particle-size fractions were collected on two types of contrasting hillslopes. (137)Cs data revealed that soil loss occurred at upper slope positions of the two landscapes and soil accumulation at the lower slope positions. Soil erosion rates as well as distribution patterns of the erosion is the major process of soil redistribution in the gentle slope landscape, while tillage erosion acts as the dominant process of soil redistribution in the steep slope landscape. In gentle slope landscapes, both SOC and MBC contents increased downslope and these distribution patterns were closely linked to soil redistribution rates. In steep slope landscapes, only SOC contents increased downslope, dependent on soil redistribution. It is noticeable that MBC/SOC ratios were significantly lower in gentle slope landscapes than in steep slope landscapes, implying that water erosion has a negative effect on the microbial biomass compared with tillage erosion. It is suggested that MBC dynamics are closely associated with soil redistribution by water erosion but independent of that by tillage erosion, while SOC dynamics are influenced by soil redistribution by both water erosion and tillage erosion.

  4. Modeling mangrove biomass using remote sensing based age and growth estimates

    Science.gov (United States)

    Lagomasino, D.; Fatoyinbo, T. E.; Feliciano, E. A.; Lee, S. K.; Trettin, C.; Mangora, M.; Rahman, M.

    2016-12-01

    Mangroves are highly regarded coastal forests because of their ecosystem services and high carbon storage potential. In addition, these forests can develop rapidly in locations where congenial environmental conditions and sediment supply are available. Monitoring the growth and age of developing mangrove forests is crucial for sustainable management and estimating carbon stocks. Combining imagery from radar and optical satellites (e.g., TanDEM-X and Landsat), we can estimate young mangrove growth and age at regional and continental scales. We used TanDEM-X radar interferometry for modeling canopy height in 2013 and Landsat to measure land cover change from 1990 to 2013. Annual NDVI composites were determined for each calendar year between 1990 and 2013. New land areas gained from the transition of water to vegetation were determined by the differences in annual NDVI composites and the reference year 2013. The year of the greatest NDVI difference that met the threshold criteria was used as the initial tree height (0 m). Annual canopy height growth rates were estimated by the duration between land generation times and 2013 canopy height models derived from TanDEM-X and very-high resolution optical data. In this presentation, we compare growth rates and biomass accumulation in mangrove forests at four river deltas; the Zambezi (Mozambique), Rufiji (Tanzania), Ganges (Bangladesh), and Mekong (Vietnam). The spatial patterns of growth rates coincided with characteristic successional paradigms and stream morphology, where the maximum growth rates typically occurred along prograding creek banks. Initial comparisons between height-only and growth-age biomass indicate that the latter tend to overestimate biomass for younger forest stands of similar height. Both the vertical (e.g., canopy height) and horizontal (e.g., expansion) growth rates measured from remote sensing can garner important information regarding mangrove succession and primary productivity. Continued research

  5. A microbial clock provides an accurate estimate of the postmortem interval in a mouse model system

    Science.gov (United States)

    Metcalf, Jessica L; Wegener Parfrey, Laura; Gonzalez, Antonio; Lauber, Christian L; Knights, Dan; Ackermann, Gail; Humphrey, Gregory C; Gebert, Matthew J; Van Treuren, Will; Berg-Lyons, Donna; Keepers, Kyle; Guo, Yan; Bullard, James; Fierer, Noah; Carter, David O; Knight, Rob

    2013-01-01

    Establishing the time since death is critical in every death investigation, yet existing techniques are susceptible to a range of errors and biases. For example, forensic entomology is widely used to assess the postmortem interval (PMI), but errors can range from days to months. Microbes may provide a novel method for estimating PMI that avoids many of these limitations. Here we show that postmortem microbial community changes are dramatic, measurable, and repeatable in a mouse model system, allowing PMI to be estimated within approximately 3 days over 48 days. Our results provide a detailed understanding of bacterial and microbial eukaryotic ecology within a decomposing corpse system and suggest that microbial community data can be developed into a forensic tool for estimating PMI. DOI: http://dx.doi.org/10.7554/eLife.01104.001 PMID:24137541

  6. Estimating aboveground tree biomass for beetle-killed lodgepole pine in the Rocky Mountains of northern Colorado

    Science.gov (United States)

    Woodam Chung; Paul Evangelista; Nathaniel Anderson; Anthony Vorster; Hee Han; Krishna Poudel; Robert Sturtevant

    2017-01-01

    The recent mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic has affected millions of hectares of conifer forests in the Rocky Mountains. Land managers are interested in using biomass from beetle-killed trees for bioenergy and biobased products, but they lack adequate information to accurately estimate biomass in stands with heavy mortality. We...

  7. A review of the challenges and opportunities in estimating above ground forest biomass using tree-level models

    Science.gov (United States)

    Hailemariam Temesgen; David Affleck; Krishna Poudel; Andrew Gray; John Sessions

    2015-01-01

    Accurate biomass measurements and analyses are critical components in quantifying carbon stocks and sequestration rates, assessing potential impacts due to climate change, locating bio-energy processing plants, and mapping and planning fuel treatments. To this end, biomass equations will remain a key component of future carbon measurements and estimation. As...

  8. The use of N 15 for studying the relation between the development of the microbial biomass and the remineralization of nitrogen fertilizer by rice

    Energy Technology Data Exchange (ETDEWEB)

    Al-Chater, M S [King Faisal University - Faculty of Agriculture and Food Science Department of Soil and Water Al-Hassa, (Saudi Arabia)

    1995-10-01

    The study aims at determining the mechanism of secondary mineralization of fertilizer N in the form of (N{sup 15} H{sub 14})2 SO{sub 4} which was transformed to the organic N using soil samples taken after a period of 16 weeks from the series of pot experiments. The development of the microbial biomass was studied using the method of Jenkinson and Powlson(1976) which was modified by Bottner et al (1984). Nitrogen mineralization was determined using the Stanford and Smith (1972) method. The study indicated that the values of mineralization constant varied from 0.0012 to 0.027 in different treatments. Accordingly, the half-life of microbial biomass ranged from 6 to 7 months, indicating fast transformation of microbial N as compared with total organic N in the soil which ranged between 7 to 12 years.1 fig., 3 tabs.

  9. To prevent the occurrence of black water agglomerate through delaying decomposition of cyanobacterial bloom biomass by sediment microbial fuel cell.

    Science.gov (United States)

    Zhou, Yan-Li; Jiang, He-Long; Cai, Hai-Yuan

    2015-04-28

    Settlement of cyanobacterial bloom biomass (CBB) into sediments in eutrophic lakes often induced the occurrence of black water agglomerate and then water quality deterioration. This study investigated the effect of sediment microbial fuel cell (SMFC) on CBB removal in sediments and related water pollution. Sediment bulking and subsequent black water from decomposition of settled CBB happened without SMFC, but were not observed over 100-day experiments with SMFC employment. While CBB in sediments improved power production from SMFC, the removal efficiency of organic matters in CBB-amended sediments with SMFC was significantly lower than that without SMFC. Pyrosequencing analysis showed higher abundances of the fermentative Clostridium and acetoclastic methanogen in CBB-amended bulk sediments without SMFC than with SMFC at the end of experiments. Obviously, SMFC operation changed the microbial community in CBB-amended sediments, and delayed the CBB degradation against sediment bulking. Thus, SMFC could be potentially applied as pollution prevention in CBB-settled and sensitive zones in shallow lakes. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. BioDry: An Inexpensive, Low-Power Method to Preserve Aquatic Microbial Biomass at Room Temperature.

    Science.gov (United States)

    Tuorto, Steven J; Brown, Chris M; Bidle, Kay D; McGuinness, Lora R; Kerkhof, Lee J

    2015-01-01

    This report describes BioDry (patent pending), a method for reliably preserving the biomolecules associated with aquatic microbial biomass samples, without the need of hazardous materials (e.g. liquid nitrogen, preservatives, etc.), freezing, or bulky storage/sampling equipment. Gel electrophoresis analysis of nucleic acid extracts from samples treated in the lab with the BioDry method indicated that molecular integrity was protected in samples stored at room temperature for up to 30 days. Analysis of 16S/18S rRNA genes for presence/absence and relative abundance of microorganisms using both 454-pyrosequencing and TRFLP profiling revealed statistically indistinguishable communities from control samples that were frozen in liquid nitrogen immediately after collection. Seawater and river water biomass samples collected with a portable BioDry "field unit", constructed from off-the-shelf materials and a battery-operated pumping system, also displayed high levels of community rRNA preservation, despite a slight decrease in nucleic acid recovery over the course of storage for 30 days. Functional mRNA and protein pools from the field samples were also effectively conserved with BioDry, as assessed by respective RT-PCR amplification and western blot of ribulose-1-5-bisphosphate carboxylase/oxygenase. Collectively, these results demonstrate that BioDry can adequately preserve a suite of biomolecules from aquatic biomass at ambient temperatures for up to a month, giving it great potential for high resolution sampling in remote locations or on autonomous platforms where space and power are limited.

  11. BioDry: An Inexpensive, Low-Power Method to Preserve Aquatic Microbial Biomass at Room Temperature.

    Directory of Open Access Journals (Sweden)

    Steven J Tuorto

    Full Text Available This report describes BioDry (patent pending, a method for reliably preserving the biomolecules associated with aquatic microbial biomass samples, without the need of hazardous materials (e.g. liquid nitrogen, preservatives, etc., freezing, or bulky storage/sampling equipment. Gel electrophoresis analysis of nucleic acid extracts from samples treated in the lab with the BioDry method indicated that molecular integrity was protected in samples stored at room temperature for up to 30 days. Analysis of 16S/18S rRNA genes for presence/absence and relative abundance of microorganisms using both 454-pyrosequencing and TRFLP profiling revealed statistically indistinguishable communities from control samples that were frozen in liquid nitrogen immediately after collection. Seawater and river water biomass samples collected with a portable BioDry "field unit", constructed from off-the-shelf materials and a battery-operated pumping system, also displayed high levels of community rRNA preservation, despite a slight decrease in nucleic acid recovery over the course of storage for 30 days. Functional mRNA and protein pools from the field samples were also effectively conserved with BioDry, as assessed by respective RT-PCR amplification and western blot of ribulose-1-5-bisphosphate carboxylase/oxygenase. Collectively, these results demonstrate that BioDry can adequately preserve a suite of biomolecules from aquatic biomass at ambient temperatures for up to a month, giving it great potential for high resolution sampling in remote locations or on autonomous platforms where space and power are limited.

  12. [Influence of different slope position and profile in Disporopsis pernyi forest land on soil microbial biomass and enzyme activity in southwest Karst mountain of China ].

    Science.gov (United States)

    Qin, Hua-Jun; He, Bing-Hui; Zhao, Xuan-chi; Li, Yuan; Mao, Wen-tao; Zeng, Qing-ping

    2014-09-01

    Soil microbial biomass and enzyme activity are important parameters to evaluate the quality of the soil environment. The goal of this study was to determine the influence of different slope position and section in Disporopsis pernyi forest land on the soil microbial biomass and enzyme activity in southwest Karst Mountain. In this study, we chose the Dip forest land at Yunfo village Chengdong town Liangping country Chongqing Province as the study object, to analyze the influence of three different slope positions [Up Slope(US), Middle Slope(MS), Below Slope(BS)] and two different sections-upper layer(0-15 cm) and bottom layer(15-30 cm) on the soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), microbial carbon entropy (qMBC), microbial nitrogen entropy (qMBN) , catalase(CAT), alkaline phosphatase (ALK), urease(URE), and invertase(INV). The results showed that the same trend (BS > MS > US) was found for SMBC, SMBN, qMBC, qMBN, CAT and INV of upper soil layer, while a different trend (BS > US > MS) was observed for ALK. In addition, another trend (MS > US > BS) was observed for URE. The same trend (BS > MS >US) was observed for SMBN, qMBN, CAT, ALK, URE and INV in bottom layer, but a different trend (MS > BS > US) was observed for SMBC and qMBC. The SMBC, SMBN, CAT, ALK, URE and INV manifested as upper > bottom with reduction of the section, while qMBC and qMBN showed the opposite trend. Correlation analysis indicated that there were significant (P <0.05) or highly significant (P < 0.01) positive correlations among SMBC in different slope position and section, soil enzyme activity and moisture. According to the two equations of regression analysis, SMBC tended to increase with the increasing CAT and ALK, while decreased with the increasing pH. Then SMBN tended to increase with the increasing URE and INV.

  13. Microbial Production of Short Chain Fatty Acids from Lignocellulosic Biomass: Current Processes and Market

    Directory of Open Access Journals (Sweden)

    Ivan Baumann

    2016-01-01

    Full Text Available Biological production of organic acids from conversion of biomass derivatives has received increased attention among scientists and engineers and in business because of the attractive properties such as renewability, sustainability, degradability, and versatility. The aim of the present review is to summarize recent research and development of short chain fatty acids production by anaerobic fermentation of nonfood biomass and to evaluate the status and outlook for a sustainable industrial production of such biochemicals. Volatile fatty acids (VFAs such as acetic acid, propionic acid, and butyric acid have many industrial applications and are currently of global economic interest. The focus is mainly on the utilization of pretreated lignocellulosic plant biomass as substrate (the carbohydrate route and development of the bacteria and processes that lead to a high and economically feasible production of VFA. The current and developing market for VFA is analyzed focusing on production, prices, and forecasts along with a presentation of the biotechnology companies operating in the market for sustainable biochemicals. Finally, perspectives on taking sustainable product of biochemicals from promise to market introduction are reviewed.

  14. Phosphorus uptake by decomposing leaf detritus: effect of microbial biomass and activity

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, P J; Elwood, J W; Newbold, J D; Webster, J R; Ferren, L A; Perkins, R E

    1984-12-01

    The dominant energy source in small woodland streams is the allochthonous input of leaves. Utilization of this energy source by stream biota establishes the patterns of secondary productivity and nutrient uptake in these ecosystems. Although leaf inputs support much of the production of macroinvertebrates and higher consumers in streams, microbes are the critical link between these organisms and the leaf resource, much of which is undigestible by higher organisms. A number of studies have indicated that stream macroinvertebrates preferentially select leaves with greater levels of microbial activity. Rates of microbial activity associated with decomposing leaves were shown to be dependent on the supply of P in one woodland stream. In other streams, leaf decomposition has been shown to be nutrient limited as well. Thus, as in many other ecosystems, maintenance of high levels of production in streams is dependent on retention and efficient recycling of nutrients. Uptake of P by microbes colonizing leaves is an important mechanism for nutrient retention in small woodland streams. In these systems, numerous debris collections efficiently retard downstream movement of particulate materials, especially decomposing leaves. Uptake of dissolved, easily transportable forms of P by microbes attached to decomposing leaves increases P retention in streams. The more rapid the rate of P uptake onto decomposing leaves for a given P supply, the shorter the P uptake length and the more times an atom of P is utilized within a given stream reach. In this study the authors examined the temporal patterns of P uptake during the early stages of leaf decomposition in streams. Patterns of P uptake were compared to patterns of other measurements of microbial activity to identify the effect of microbial succession or conditioning of leaves on P uptake. 22 references, 1 figure, 2 tables.

  15. Root systems and soil microbial biomass under no-tillage system

    Directory of Open Access Journals (Sweden)

    Venzke Filho Solismar de Paiva

    2004-01-01

    Full Text Available Some root parameters such as distribution, length, diameter and dry matter are inherent to plant species. Roots can influence microbial population during vegetative cycle through the rhizodeposits and, after senescence, integrating the soil organic matter pool. Since they represent labile substrates, especially regarding nitrogen, they can determine the rate of nutrient availability to the next crop cultivated under no-tillage (NT. The root systems of two crop species: maize (Zea mays L. cultivar Cargill 909 and soybean [Glycine max (L. Merr.] cultivar Embrapa 59, were compared in the field, and their influence on spatial distribution of the microbial C and N in a clayey-textured Typic Hapludox cultivated for 22 years under NT, at Tibagi, State of Paraná (PR, Brazil, was determined. Digital image processing and nail-plate techniques were used to evaluate 40 plots of a 80 ´ 50 ´ 3 cm soil profile. It was observed that 36% and 30% of the maize and soybeans roots, respectively, are concentrated in the 0 to 10 cm soil layer. The percent distribution of root dry matter was similar for both crops. The maize roots presented a total of 1,324 kg C ha-1 and 58 kg N ha-1, with higher root dry matter density and more roots in decomposition in the upper soil layer, decreasing with depth. The soybean roots (392 kg C ha-1 and 21 kg N ha-1 showed higher number of thinner roots and higher density per length unity compared to the maize. The maize roots enhanced microbial-C down to deeper soil layers than did the soybean roots. The microbial N presented a better correlation with the concentration of thin active roots and with roots in decomposition or in indefinite shape, possibly because of higher concentration of C and N easily assimilated by soil microorganisms.

  16. A hyperspectral approach to estimating biomass and plant production in a heterogeneous restored temperate peatland

    Science.gov (United States)

    Byrd, K. B.; Schile, L. M.; Windham-Myers, L.; Kelly, M.; Hatala, J.; Baldocchi, D. D.

    2012-12-01

    Restoration of drained peatlands that are managed to reverse subsidence through organic accretion holds significant potential for large-scale carbon storage and sequestration. This potential has been demonstrated in an experimental wetland restoration site established by the U.S. Geological Survey in 1997 on Twitchell Island in the Sacramento-San Joaquin River Delta, where soil carbon storage is up to 1 kg C m-2 and root and rhizome production can reach over 7 kg m-2 annually. Remote sensing-based estimation of biomass and productivity over a large spatial extent helps to monitor carbon storage potential of these restored peatlands. Extensive field measurements of plant biophysical characteristics such as biomass, leaf area index, and the fraction of absorbed photosynthetically active radiation (fAPAR) [an important variable in light-use efficiency (LUE) models] have been collected for agricultural systems and forests. However the small size and local spatial variability of U.S. Pacific Coast wetlands pose new challenges for measuring these variables in the field and generating estimates through remote sensing. In particular background effects of non-photosynthetic vegetation (NPV), floating aquatic vegetation, and inundation of wetland vegetation influence the relationship between field measurements and multispectral or hyperspectral indices. Working at the USGS experimental wetland site, characterized by variable water depth and substantial NPV, or thatch, we collected field data on hardstem bulrush (Schoenoplectus acutus) and cattail (Typha spp.) coupled with reflectance data from a field spectrometer (350-2500 nm) every two to three weeks during the summers of 2011 and 2012. We calculated aboveground biomass with existing allometric relationships, and fAPAR was measured with line and point quantum sensors. We analyzed reflectance data to develop hyperspectral and multispectral indices that predict biomass and fAPAR and account for background effects of water

  17. Impact of biomass burning on urban air quality estimated by organic tracers: Guangzhou and Beijing as cases

    International Nuclear Information System (INIS)

    Qiaoqiao Wang; Min Shao; Ying Liu; Kuster, William; Goldan, Paul; Xiaohua Li; Yuan Liu; Sihua Lu

    2007-01-01

    The impacts of biomass burning have not been adequately studied in China. In this work, chemical compositions of volatile organic compounds and particulate organic matters were measured in August 2005 in Beijing and in October 2004 in Guangzhou city. The performance of several possible tracers for biomass burning is compared by using acetonitrile as a reference compound. The correlations between the possible tracers and acetonitrile show that the use of K + as a tracer could result in bias because of the existence of other K+ sources in urban areas, while chloromethane is not reliable due to its wide use as industrial chemical. The impact of biomass burning on air quality is estimated using acetonitrile and levoglucosan as tracers. The results show that the impact of biomass burning is ubiquitous in both suburban and urban Guangzhou, and the frequencies of air pollution episodes significantly influenced by biomass burning were 100% for Xinken and 58% for downtown Guangzhou city. Fortunately, the air quality in only 2 out of 22 days was partly impacted by biomass burning in August in Beijing, the month that 2008 Olympic games will take place. The quantitative contribution of biomass burning to ambient PM 2.5 concentrations in Guangzhou city was also estimated by the ratio of levoglocusan to PM 2.5 in both the ambient air and biomass burning plumes. The results show that biomass burning contributes 3.02013;16.8% and 4.02013;19.0% of PM 2.5 concentrations in Xinken and Guangzhou downtown, respectively. (Author)

  18. Soil microbial activities and its relationship with soil chemical ...

    African Journals Online (AJOL)

    The fields assessed are organically managed Soils (OMS), Inorganically Managed Soils (IMS) and an Uncultivated Land having grass coverage (ULS). Soil Microbial Respiration (SMR), Microbial Biomass Carbon (MBC), Microbial Biomass Nitrogen (MBN) and Microbial Biomass Phosphorus (MBP) were analyzed.

  19. Evaluation of Above Ground Biomass Estimation Accuracy for Alpine Meadow Based on MODIS Vegetation Indices

    Directory of Open Access Journals (Sweden)

    Meng Bao-Ping

    2017-01-01

    Full Text Available Animal husbandry is the main agricultural type over the Tibetan Plateau, above ground biomass (AGB is very important to monitor the productivity for administration of grassland resources and grazing balance. The MODIS vegetation indices have been successfully used in numerous studies on grassland AGB estimation in the Tibetan Plateau area. However, there are considerable differences of AGB estimation models both in the form of the models and the accuracy of estimation. In this study, field measurements of AGB data at Sangke Town, Gansu Province, China in four years (2013-2016 and MODIS indices (NDVI and EVI are combined to construct AGB estimation models of alpine meadow grassland. The field measured AGB are also used to evaluate feasibility of models developed for large scale in applying to small area. The results show that (1 the differences in biomass were relatively large among the 5 sample areas of alpine meadow grassland in the study area during 2013-2016, with the maximum and minimum biomass values of 3,963 kg DW/ha and 745.5 kg DW/ha, respectively, and mean value of 1,907.7 kg DW/ha; the mean of EVI value range (0.42-0.60 are slightly smaller than the NDVI’s (0.59-0.75; (2 the optimum estimation model of grassland AGB in the study area is the exponential model based on MODIS EVI, with root mean square error of 656.6 kg DW/ha and relative estimation errors (REE of 36.3%; (3 the estimation errors of grassland AGB models previously constructed at different spatial scales (the Tibetan Plateau, the Gannan Prefecture, and Xiahe County are higher than those directly constructed based on the small area of this study by 9.5%–31.7%, with the increase of the modeling study area scales, the REE increasing as well. This study presents an improved monitoring algorithm of alpine natural grassland AGB estimation and provides a clear direction for future improvement of the grassland AGB estimation and grassland productivity from remote sensing

  20. Estimation of Viable Biomass In Wastewater And Activated Sludge By Determination of ATP, Oxygen Utilization Rate And FDA Hydrolysis

    DEFF Research Database (Denmark)

    Jørgensen, Poul-Erik; Eriksen, T.; Jensen, B.K.

    1992-01-01

    ATP content, oxygen utilization rate (OUR) and fluorescein diacetate (FDA) hydrolysis were tested for the ability to express the amount of viable biomass in wastewater and activated sludge. The relationship between biomass and these activity parameters was established in growth cultures made...... with biomass, while FDA hydrolysis in the sludge failed to show any such correlation. Conversion factors of 3 mg ATP/g dw, 300 mg O2/h g dw and 0.4 A/h (mg dw/ml) for ATP, OUR and FDA methods, respectively, were calculated. When the methods were applied for in situ determinations in four different wastewater...... plants, it was found that ATP content and respiration rate estimated viable biomass to range from 81 to 293 mg dw/g SS for raw wastewater and from 67 to 187 mg dw/g SS for activated sludge with a rather weak correlation between ATP and respiration measurements. The FDA hydrolysis estimated viable biomass...

  1. Estimating Winter Annual Biomass in the Sonoran and Mojave Deserts with Satellite- and Ground-Based Observations

    Directory of Open Access Journals (Sweden)

    Bradley C. Reed

    2013-02-01

    Full Text Available Winter annual plants in southwestern North America influence fire regimes, provide forage, and help prevent erosion. Exotic annuals may also threaten native species. Monitoring winter annuals is difficult because of their ephemeral nature, making the development of a satellite monitoring tool valuable. We mapped winter annual aboveground biomass in the Desert Southwest from satellite observations, evaluating 18 algorithms using time-series vegetation indices (VI. Field-based biomass estimates were used to calibrate and evaluate each algorithm. Winter annual biomass was best estimated by calculating a base VI across the period of record and subtracting it from the peak VI for each winter season (R2 = 0.92. The normalized difference vegetation index (NDVI derived from 8-day reflectance data provided the best estimate of winter annual biomass. It is important to account for the timing of peak vegetation when relating field-based estimates to satellite VI data, since post-peak field estimates may indicate senescent biomass which is inaccurately represented by VI-based estimates. Images generated from the best-performing algorithm show both spatial and temporal variation in winter annual biomass. Efforts to manage this variable resource would be enhanced by a tool that allows the monitoring of changes in winter annual resources over time.

  2. Estimation of potential biomass resource and biogas production from aquatic plants in Argentina

    Science.gov (United States)

    Fitzsimons, R. E.; Laurino, C. N.; Vallejos, R. H.

    1982-08-01

    The use of aquatic plants in artificial lakes as a biomass source for biogas and fertilizer production through anaerobic fermentation is evaluated, and the magnitude of this resource and the potential production of biogas and fertilizer are estimated. The specific case considered is the artificial lake that will be created by the construction of Parana Medio Hydroelectric Project on the middle Parana River in Argentina. The growth of the main aquatic plant, water hyacinth, on the middle Parana River has been measured, and its conversion to methane by anaerobic fermentation is determined. It is estimated that gross methane production may be between 1.0-4.1 x 10 to the 9th cu cm/year. The fermentation residue can be used as a soil conditioner, and it is estimated production of the residue may represent between 54,900-221,400 tons of nitrogen/year, a value which is 2-8 times the present nitrogen fertilizer demand in Argentina.

  3. Hydroacoustic estimates of fish biomass and spatial distributions in shallow lakes

    Science.gov (United States)

    Lian, Yuxi; Huang, Geng; Godlewska, Małgorzata; Cai, Xingwei; Li, Chang; Ye, Shaowen; Liu, Jiashou; Li, Zhongjie

    2018-03-01

    We conducted acoustical surveys with a horizontal beam transducer to detect fish and with a vertical beam transducer to detect depth and macrophytes in two typical shallow lakes along the middle and lower reaches of the Changjiang (Yangtze) River in November 2013. Both lakes are subject to active fish management with annual stocking and removal of large fish. The purpose of the study was to compare hydroacoustic horizontal beam estimates with fish landings. The preliminary results show that the fish distribution patterns differed in the two lakes and were affected by water depth and macrophyte coverage. The hydroacoustically estimated fish biomass matched the commercial catch very well in Niushan Lake, but it was two times higher in Kuilei Lake. However, acoustic estimates included all fish, whereas the catch included only fish >45 cm (smaller ones were released). We were unable to determine the proper regression between acoustic target strength and fish length for the dominant fish species in the two lakes.

  4. Spatial distribution of forest aboveground biomass estimated from remote sensing and forest inventory data in New England, USA

    Science.gov (United States)

    Daolan Zheng; Linda S. Heath; Mark J. Ducey

    2008-01-01

    We combined satellite (Landsat 7 and Moderate Resolution Imaging Spectrometer) and U.S. Department of Agriculture forest inventory and analysis (FIA) data to estimate forest aboveground biomass (AGB) across New England, USA. This is practical for large-scale carbon studies and may reduce uncertainty of AGB estimates. We estimate that total regional forest AGB was 1,867...

  5. Sorption studies of radioiodine on soils with special references to soil microbial biomass

    Energy Technology Data Exchange (ETDEWEB)

    Bors, J. (Niedersaechsisches Inst. fuer Radiooekologie, Hannover (Germany, F.R.)); Erten, H. (Bilkent Univ., Ankara (Turkey). Dept. of Chemistry); Martens, R. (Bundesforschungsanstalt fuer Landwirtschaft, Braunschweig (Germany, F.R.). Inst. fuer Bodenbiologie)

    1991-01-01

    In batch experiments with two types of soils, chernozem and podzol, radioiodine ({sup 125}I) showed an initial rapid sorption, followed by a long and slow further increase. Very little sorption (R{sub d} < 1) was detected in clay minerals. Generally, higher R{sub d}-values were observed for the chernozem soil, characterized by a higher amount of organic substance and of soil biomass. The sorption process was predominantly irreversible, the isotherms were linear at low ion concentrations and deviated from linearity starting at 10{sup -5} mmol.ml{sup -1}. Sorption ratio was found to increase with increasing volume to mass ratio. The composition of liquid phases (bidistilled water, synthetic soil water, rain water) highly affected iodine sorption. In experiments with KBr solution, the sorption of I{sup -} was found to be strongly preferred to Br{sup -}. Incubation of soil samples under varied conditions (decreased or increased soil biomass, O{sub 2}-concentration, incubation temperature, soil water content and storage conditions) delivered indications for the participation of soil microflora in iodine immobilization. Test with isolated soil bacteria and fungi showed that radioiodine can be incorporated by soil microorganisms under certain conditions only: Considerable uptake of radioiodine was found in washed (NaCl, CaCl{sub 2}) cells with both bacteria and fungi, but no incorporation was detected into cells incubated with radioiodine in the culture medium. (orig.).

  6. Sorption studies of radioiodine on soils with special references to soil microbial biomass

    International Nuclear Information System (INIS)

    Bors, J.; Erten, H.; Martens, R.

    1991-01-01

    In batch experiments with two types of soils, chernozem and podzol, radioiodine ( 125 I) showed an initial rapid sorption, followed by a long and slow further increase. Very little sorption (R d d -values were observed for the chernozem soil, characterized by a higher amount of organic substance and of soil biomass. The sorption process was predominantly irreversible, the isotherms were linear at low ion concentrations and deviated from linearity starting at 10 -5 mmol.ml -1 . Sorption ratio was found to increase with increasing volume to mass ratio. The composition of liquid phases (bidistilled water, synthetic soil water, rain water) highly affected iodine sorption. In experiments with KBr solution, the sorption of I - was found to be strongly preferred to Br - . Incubation of soil samples under varied conditions (decreased or increased soil biomass, O 2 -concentration, incubation temperature, soil water content and storage conditions) delivered indications for the participation of soil microflora in iodine immobilization. Test with isolated soil bacteria and fungi showed that radioiodine can be incorporated by soil microorganisms under certain conditions only: Considerable uptake of radioiodine was found in washed (NaCl, CaCl 2 ) cells with both bacteria and fungi, but no incorporation was detected into cells incubated with radioiodine in the culture medium. (orig.)

  7. The removal of uranium from mining waste water using algal/microbial biomass

    International Nuclear Information System (INIS)

    Kalin, Margarete; Wheeler, W.N.; Meinrath, G.

    2004-01-01

    We describe a three step process for the removal of uranium (U) from dilute waste waters. Step one involves the sequestration of U on, in, and around aquatic plants such as algae. Cell wall ligands efficiently remove U(VI) from waste water. Growing algae continuously renew the cellular surface area. Step 2 is the removal of U-algal particulates from the water column to the sediments. Step 3 involves reducing U(VI) to U(IV) and transforming the ions into stable precipitates in the sediments. The algal cells provide organic carbon and other nutrients to heterotrophic microbial consortia to maintain the low E H , within which the U is transformed. Among the microorganisms, algae are of predominant interest for the ecological engineer because of their ability to sequester U and because some algae can live under many extreme environments, often in abundance. Algae grow in a wide spectrum of water qualities, from alkaline environments (Chara, Nitella) to acidic mine drainage waste waters (Mougeotia, Ulothrix). If they could be induced to grow in waste waters, they would provide a simple, long-term means to remove U and other radionuclides from U mining effluents. This paper reviews the literature on algal and microbial adsorption, reduction, and transformation of U in waste streams, wetlands, lakes and oceans

  8. Estimating and mapping forest biomass using regression models and Spot-6 images (case study: Hyrcanian forests of north of Iran).

    Science.gov (United States)

    Motlagh, Mohadeseh Ghanbari; Kafaky, Sasan Babaie; Mataji, Asadollah; Akhavan, Reza

    2018-05-21

    Hyrcanian forests of North of Iran are of great importance in terms of various economic and environmental aspects. In this study, Spot-6 satellite images and regression models were applied to estimate above-ground biomass in these forests. This research was carried out in six compartments in three climatic (semi-arid to humid) types and two altitude classes. In the first step, ground sampling methods at the compartment level were used to estimate aboveground biomass (Mg/ha). Then, by reviewing the results of other studies, the most appropriate vegetation indices were selected. In this study, three indices of NDVI, RVI, and TVI were calculated. We investigated the relationship between the vegetation indices and aboveground biomass measured at sample-plot level. Based on the results, the relationship between aboveground biomass values and vegetation indices was a linear regression with the highest level of significance for NDVI in all compartments. Since at the compartment level the correlation coefficient between NDVI and aboveground biomass was the highest, NDVI was used for mapping aboveground biomass. According to the results of this study, biomass values were highly different in various climatic and altitudinal classes with the highest biomass value observed in humid climate and high-altitude class.

  9. OPTIMAL WAVELENGTH SELECTION ON HYPERSPECTRAL DATA WITH FUSED LASSO FOR BIOMASS ESTIMATION OF TROPICAL RAIN FOREST

    Directory of Open Access Journals (Sweden)

    T. Takayama

    2016-06-01

    Full Text Available Above-ground biomass prediction of tropical rain forest using remote sensing data is of paramount importance to continuous large-area forest monitoring. Hyperspectral data can provide rich spectral information for the biomass prediction; however, the prediction accuracy is affected by a small-sample-size problem, which widely exists as overfitting in using high dimensional data where the number of training samples is smaller than the dimensionality of the samples due to limitation of require time, cost, and human resources for field surveys. A common approach to addressing this problem is reducing the dimensionality of dataset. Also, acquired hyperspectral data usually have low signal-to-noise ratio due to a narrow bandwidth and local or global shifts of peaks due to instrumental instability or small differences in considering practical measurement conditions. In this work, we propose a methodology based on fused lasso regression that select optimal bands for the biomass prediction model with encouraging sparsity and grouping, which solves the small-sample-size problem by the dimensionality reduction from the sparsity and the noise and peak shift problem by the grouping. The prediction model provided higher accuracy with root-mean-square error (RMSE of 66.16 t/ha in the cross-validation than other methods; multiple linear analysis, partial least squares regression, and lasso regression. Furthermore, fusion of spectral and spatial information derived from texture index increased the prediction accuracy with RMSE of 62.62 t/ha. This analysis proves efficiency of fused lasso and image texture in biomass estimation of tropical forests.

  10. Crop biomass and evapotranspiration estimation using SPOT and Formosat-2 Data

    Science.gov (United States)

    Veloso, Amanda; Demarez, Valérie; Ceschia, Eric; Claverie, Martin

    2013-04-01

    The use of crop models allows simulating plant development, growth and yield under different environmental and management conditions. When combined with high spatial and temporal resolution remote sensing data, these models provide new perspectives for crop monitoring at regional scale. We propose here an approach to estimate time courses of dry aboveground biomass, yield and evapotranspiration (ETR) for summer (maize, sunflower) and winter crops (wheat) by assimilating Green Area Index (GAI) data, obtained from satellite observations, into a simple crop model. Only high spatial resolution and gap-free satellite time series can provide enough information for efficient crop monitoring applications. The potential of remote sensing data is often limited by cloud cover and/or gaps in observation. Data from different sensor systems need then to be combined. For this work, we employed a unique set of Formosat-2 and SPOT images (164 images) and in-situ measurements, acquired from 2006 to 2010 in southwest France. Among the several land surface biophysical variables accessible from satellite observations, the GAI is the one that has a key role in soil-plant-atmosphere interactions and in biomass accumulation process. Many methods have been developed to relate GAI to optical remote sensing signal. Here, seasonal dynamics of remotely sensed GAI were estimated by applying a method based on the inversion of a radiative transfer model using artificial neural networks. The modelling approach is based on the Simple Algorithm for Yield and Evapotranspiration estimate (SAFYE) model, which couples the FAO-56 model with an agro-meteorological model, based on Monteith's light-use efficiency theory. The SAFYE model is a daily time step crop model that simulates time series of GAI, dry aboveground biomass, grain yield and ETR. Crop and soil model parameters were determined using both in-situ measurements and values found in the literature. Phenological parameters were calibrated by the

  11. Estimation of the duodenal flow of microbial nitrogen in ruminants based on the chemical composition of forages: a literature review

    NARCIS (Netherlands)

    Gosselink, J.M.J.; Poncet, C.; Dulphy, J.P.; Cone, J.W.

    2003-01-01

    The objective of this study was to evaluate the estimation of the duodenal flow of microbial nitrogen (N) in ruminants fed forage only, per kilogram of dry matter (DM) intake, which is the yield of microbial protein (YMP). The estimation was based on the chemical composition of forages. A data file

  12. Estimating and comparing microbial diversity in the presence of sequencing errors

    Science.gov (United States)

    Chiu, Chun-Huo

    2016-01-01

    Estimating and comparing microbial diversity are statistically challenging due to limited sampling and possible sequencing errors for low-frequency counts, producing spurious singletons. The inflated singleton count seriously affects statistical analysis and inferences about microbial diversity. Previous statistical approaches to tackle the sequencing errors generally require different parametric assumptions about the sampling model or about the functional form of frequency counts. Different parametric assumptions may lead to drastically different diversity estimates. We focus on nonparametric methods which are universally valid for all parametric assumptions and can be used to compare diversity across communities. We develop here a nonparametric estimator of the true singleton count to replace the spurious singleton count in all methods/approaches. Our estimator of the true singleton count is in terms of the frequency counts of doubletons, tripletons and quadrupletons, provided these three frequency counts are reliable. To quantify microbial alpha diversity for an individual community, we adopt the measure of Hill numbers (effective number of taxa) under a nonparametric framework. Hill numbers, parameterized by an order q that determines the measures’ emphasis on rare or common species, include taxa richness (q = 0), Shannon diversity (q = 1, the exponential of Shannon entropy), and Simpson diversity (q = 2, the inverse of Simpson index). A diversity profile which depicts the Hill number as a function of order q conveys all information contained in a taxa abundance distribution. Based on the estimated singleton count and the original non-singleton frequency counts, two statistical approaches (non-asymptotic and asymptotic) are developed to compare microbial diversity for multiple communities. (1) A non-asymptotic approach refers to the comparison of estimated diversities of standardized samples with a common finite sample size or sample completeness. This

  13. Microbial community distribution and activity dynamics of granular biomass in a CANON reactor

    DEFF Research Database (Denmark)

    Vázquez-Padín, Jose; Mosquera-Corral, Anuska; Campos, Jose Luis

    2010-01-01

     (Lgranule)-1 d-1. Anammox activity was registered between 400 and 1000 μm depth inside the granules. The nitrogen removal capacity of the studied sequencing batch reactor containing the granular biomass was of 0.5 g N L-1 d-1. This value is similar to the mean nitrogen removal rate obtained from...... calculations based on in- and outflow concentrations. Information obtained in the present work allowed the establishment of a simple control strategy based on the measurements of NH4+ and NO2- in the bulk liquid and acting over the dissolved oxygen concentration in the bulk liquid and the hydraulic retention...

  14. Model-Assisted Estimation of Tropical Forest Biomass Change: A Comparison of Approaches

    Directory of Open Access Journals (Sweden)

    Nikolai Knapp

    2018-05-01

    Full Text Available Monitoring of changes in forest biomass requires accurate transfer functions between remote sensing-derived changes in canopy height (ΔH and the actual changes in aboveground biomass (ΔAGB. Different approaches can be used to accomplish this task: direct approaches link ΔH directly to ΔAGB, while indirect approaches are based on deriving AGB stock estimates for two points in time and calculating the difference. In some studies, direct approaches led to more accurate estimations, while, in others, indirect approaches led to more accurate estimations. It is unknown how each approach performs under different conditions and over the full range of possible changes. Here, we used a forest model (FORMIND to generate a large dataset (>28,000 ha of natural and disturbed forest stands over time. Remote sensing of forest height was simulated on these stands to derive canopy height models for each time step. Three approaches for estimating ΔAGB were compared: (i the direct approach; (ii the indirect approach and (iii an enhanced direct approach (dir+tex, using ΔH in combination with canopy texture. Total prediction accuracies of the three approaches measured as root mean squared errors (RMSE were RMSEdirect = 18.7 t ha−1, RMSEindirect = 12.6 t ha−1 and RMSEdir+tex = 12.4 t ha−1. Further analyses revealed height-dependent biases in the ΔAGB estimates of the direct approach, which did not occur with the other approaches. Finally, the three approaches were applied on radar-derived (TanDEM-X canopy height changes on Barro Colorado Island (Panama. The study demonstrates the potential of forest modeling for improving the interpretation of changes observed in remote sensing data and for comparing different methodologies.

  15. [Effects of different application rates of calcium cyanamide on soil microbial biomass and enzyme activity in cucumber continuous cropping].

    Science.gov (United States)

    Zhang, Xue-peng; Ning, Tang-yuan; Yang, Yan; Sun, Tao; Zhang, Shu-min; Wang, Bin

    2015-10-01

    A 2-year field experiment was conducted to study the effects of CaCN2 combined with cucumber straw retention on soil microbial biomass carbon (SMBC) , soil microbial biomass nitrogen (SMBN) and soil enzyme activities under cucumber continuous cropping system. Four treatments were used in this study as follows: CK (null CaCN2), CaCN2-90 (1350 kg CaCN2 . hm-2) CaCN2-60 (900 kg CaCN2 . hm-2), CaCN2-30 (450 kg CaCN2 . hm-2). The results indicated that, compared with the other treatments, CaCN2-90 treatment significantly decreased SMBC in 0-10 cm soil layer at seedling stage, but increased SMBC in 0-20 cm soil layer after early-fruit stage. Compared with CK, CaCN2 increased SMBC in 0-20 cm soil layer at late-fruit stage, and increased SMBN in 0-10 cm soil layer at mid- and late-fruit stages, however there was no significant trend among CaCN2 treatments in the first year (2012), while in the second year (2013) SMBN increased with the increasing CaCN2 amount after mid-fruit stage. CaCN2 increased straw decaying and nutrients releasing, and also increased soil organic matter. Furthermore, the CaCN2-90 could accelerate straw decomposition. Compared with CK, CaCN2 effectively increased soil urease, catalase and polyphenol oxidase activity. The soil urease activity increased while the polyphenol oxidase activity decreased with the increase of CaCN2, and CaCN2-60 could significantly improve catalase activity. Soil organic matter, urease activity and catalase activity had significant positive correlations with SMBC and SMBN. However, polyphenol oxidase activity was negatively correlated to SMBC and SMBN. Our findings indicated that CaCN2 application at 900 kg . hm-2 combined with cucumber straw retention could effectively improve soil environment, alleviating the soil obstacles under the cucumber continuous cropping system.

  16. Mineralisation of low concentrations of organic compounds and microbial biomass in surface and vadose zone soils from the Swan Coastal Plain, Western Australia

    International Nuclear Information System (INIS)

    Franzmann, P. D.; Zappia, L. R.; Patterson, B. M.; Rayner, J.L.; Davis, G. B.

    1998-01-01

    Mineralisation rates for ring-labelled 14 C-atrazine, benzene, and toluene were determined for a number of Swan Coastal Plain soils which had not been previously in contact with these contaminants. Microbial biomass was estimated by phospholipid techniques in soil samples from the same sites. Mineralisation rates for the volatile aromatic hydrocarbons in the thin (up to 30 cm) surface soils (23.4-42.6 μmol/kg . day when fitted to zeroth-order rate kinetics) were appreciably faster than the mineralisation rates measured in soils collected from a depth of 1 m (0.11-3.0 μmol/kg per day). The pesticide atrazine was degraded slowly, with degradation rates in surface soils ranging from 1.22x10 -3 to 2.78x10 -4 μmol/kg . day, and those in soils at 1 m ranging from 5. 13x10 -4 to 3.1610 -4 μmol/kg per day. When mineralisation data were fitted to first-order kinetics then half-lives for atrazine mineralisation ranged from about 1 year in surface soils to 3.1-5.1 years in soils at 1 m. These rates were comparable to atrazine mineralisation rates measured in soils that had not been previously in contact with atrazine, as reported by others. The extent of mineralisation of the organic compounds v. time generally fitted better to zeroth-order kinetics than to first-order kinetics. Confidence in the determination of the mineralisation rate at slow rates of mineralisation was low (r 2 as low as 0.2 in plots of the extent of mineralisation v. time in zeroth-order and first-order plots for samples that showed slow mineralisation). Biomass, expressed as stationary phase Escherichia coli equivalents (SPEE), ranged from 1.4 x10 7 to 1x2x10 8 SPEE/g dry weight for surface soils, and from 8.6x10 5 to 7.3x10 6 SPEE/g dry weight for soils at 1 m. The phospholipids extracted from surface soils tended to contain higher proportions of unsaturated and hydroxy fatty acids than soils at 1 m, which contained higher relative concentrations of branched fatty acids, which is consistent with the

  17. Remote Sensing-based estimates of herbaceous aboveground biomass on the Mongolian Plateau

    Science.gov (United States)

    John, R.; Chen, J.; Kim, Y.; Ouyang, Z.; Park, H.; Shao, C.

    2015-12-01

    Grasslands comprise most of the land area on the Mongolian Plateau, which includes Mongolia (MG), and the province of Inner Mongolia (IM). Substantial land cover/use change in the recent past, driven by a combination of post-liberalization, socio-economic changes as well as extreme climatic events has resulted in degradation of grasslands in structure and function, for e.g., their carbon sequestration ability. Hence there is a need for precise estimation of above-ground biomass (AGB). In this study, we collected surface reflectance spectra from field radiometry and quadrats and line transects, which include percentage of ground cover, vegetation height, above ground biomass, and species richness, during the growing season, between the periods, 2006-2011 in IM and 2011-2015 in MG. The field sampling was stratified by the dominant vegetation types on the plateau, including the meadow steppe, typical steppe, and the desert steppe. These sampling data were used as training and validation data for developing and testing predictive models for total herbaceous vegetation, and AGB, using Landsat and MODIS-surface reflectance bands and derived vegetation indices optimized for low cover conditions. Our results show that the independent ground sampling data were significantly correlated with remotely sensed estimates. In addition to providing measures of carbon sequestration to the community, these predictive models offer decision makers and rangeland managers the ability to accurately monitor grassland dynamics, control livestock stocking rates in these remote and extensive grasslands.

  18. In vitro estimation of rumen microbial protein synthesis of water buffaloes using 30S as tracer

    International Nuclear Information System (INIS)

    Hendratno, C.; Abidin, Z.; Bahaudin, R.; Sastrapradja, D.

    1977-01-01

    An experiment to study the effect of diet and individual differences of animals on the in vitro estimation of rumen microbial protein synthesis in young female water buffaloes using the technique of inorganic 35 S incorporation, is described. The dietary treatments were four combinations of roughage supplemented with cassava meal. From the value of rate constant for dilution of radioactivity in the sulphide pool and percentage of inorganic 35 S incorporated into microbial protein, it can be concluded that individual differences of animals have no influence on the efficiency of microbial protein synthesis. Feed composition, on the other hand, tends to have some influence on the efficiency of protein synthesis(P3O.15). (author)

  19. Functional soil microbial diversity across Europe estimated by EEA, MicroResp and BIOLOG

    DEFF Research Database (Denmark)

    Winding, Anne; Rutgers, Michiel; Creamer, Rachel

    consisting of 81 soil samples covering five Biogeograhical Zones and three land-uses in order to test the sensitivity, ease and cost of performance and biological significance of the data output. The techniques vary in how close they are to in situ functions; dependency on growth during incubation......Soil microorganisms are abundant and essential for the bio-geochemical processes of soil, soil quality and soil ecosystem services. All this is dependent on the actual functions the microbial communities are performing in the soil. Measuring soil respiration has for many years been the basis...... of estimating soil microbial activity. However, today several techniques are in use for determining microbial functional diversity and assessing soil biodiversity: Methods based on CO2 development by the microbes such as substrate induced respiration (SIR) on specific substrates have lead to the development...

  20. Allometric Equations for Estimating Biomass of Euterpe precatoria, the Most Abundant Palm Species in the Amazon

    Directory of Open Access Journals (Sweden)

    Fernando Da Silva

    2015-02-01

    Full Text Available Allometric models to estimate biomass components such as stem mass Ms, foliage mass Ml, root mass Mr and aboveground mass Ma, were developed for the palm species Euterpe precatoria Mart., which is the most abundant tree species in the Amazon. We harvested twenty palms including above- and below-ground parts in an old growth Amazonian forest in Brazil. The diameter at breast height D ranged from 3.9–12.7 cm, and the stem height H ranged from 2.3–16.4 m. The D, diameter at ground basis D0, crown diameter CD, H, stem specific gravity ρ, and number of fronds Nf were considered as independent variables and incorporated into a power function model. The best predictors were D2Hρ for Ms and Ma, D2HNf for Ml, and D for Mr. Slender index (H/D ranged from 0.56–1.46 m·cm−1, and the D-H relationship suggested that the stem shape becomes more slender with increasing D. On the other hand, ρ increased with D implying a stiffening of stem tissue. The average root/shoot ratio was estimated as 0.29 which was higher than that reported for the non-palm tree species in the Amazon. Comparisons of several models to estimate Ma of different palm species, suggested that the variations of the D-H relationship and ρ should be considered to develop allometric models for estimating biomass in palm species. In particular the ρ largely varied depending on individual size, which should be important to consider, when developing the allometric models for palms.

  1. Contribution of the thraustochytrid Corallochytrium limacisporum Raghu-kumar to microbial biomass in coral reef lagoons

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, S.; Chandramohan, D.; Ramaiah, N.

    ATP and organic carbon (OC) contents of cells of 5 isolates of thraustochytrids, including one of Corallochytrium limacisporum were estimated from cultures OC:ATP ratio in these isolates averaged 99 Based on these and the data collected...

  2. Decomposition of organic matter labelled with 14C, and microbial biomass formation in an acid soil from Piracicaba, Sao Paulo State, Brazil

    International Nuclear Information System (INIS)

    Cerri, C.C.; Volkoff, B.

    1982-01-01

    An experiment was carried out under laboratory conditions (25 0 C, 50% field capacity), using 14 C labelled sugar cane leaves, which were incorporated to a medium texture Dark-Red Latosol. The equivalent of 1 mg C/g was added to soil containing 14 mg native soil carbon. CO 2 release and microbial biomass were periodically determined. After 67 days incubation it was noted that release of native carbon was greater from soil with plant material than the control (724 μg C/g vs 424 μg/g) and that 25% of the incorporated carbon had been mineralized. Addition of plant material doubled the soil microbial biomass, which was formed due to plant material addition rather than to native soil carbon. (Author) [pt

  3. Effects of heavy metals and soil physicochemical properties on wetland soil microbial biomass and bacterial community structure.

    Science.gov (United States)

    Zhang, Chang; Nie, Shuang; Liang, Jie; Zeng, Guangming; Wu, Haipeng; Hua, Shanshan; Liu, Jiayu; Yuan, Yujie; Xiao, Haibing; Deng, Linjing; Xiang, Hongyu

    2016-07-01

    Heavy metals (HMs) contamination is a serious environmental issue in wetland soil. Understanding the micro ecological characteristic of HMs polluted wetland soil has become a public concern. The goal of this study was to identify the effects of HMs and soil physicochemical properties on soil microorganisms and prioritize some parameters that contributed significantly to soil microbial biomass (SMB) and bacterial community structure. Bacterial community structure was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Relationships between soil environment and microorganisms were analyzed by correlation analysis and redundancy analysis (RDA). The result indicated relationship between SMB and HMs was weaker than SMB and physicochemical properties. The RDA showed all eight parameters explained 74.9% of the variation in the bacterial DGGE profiles. 43.4% (contain the variation shared by Cr, Cd, Pb and Cu) of the variation for bacteria was explained by the four kinds of HMs, demonstrating HMs contamination had a significant influence on the changes of bacterial community structure. Cr solely explained 19.4% (pstructure, and Cd explained 17.5% (pstructure changes. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Fluctuation of microbial activities after influent load variations in a full-scale SBR. Recovery of the biomass after starvation

    Energy Technology Data Exchange (ETDEWEB)

    Cabezas, Angela; Draper, Patricia; Etchebehere, Claudia [Universidad de la Republica, Montevideo (Uruguay). Catedra de Microbiologia, Facultad de Quimica y Facultad de Ciencias

    2009-10-15

    Due to variations in the production levels, a full-scale sequencing batch reactor (SBR) for post-treatment of tannery wastewater was exposed to low and high ammonia load periods. In order to study how these changes affected the N-removal capacity, the microbiology of the reactor was studied by a diverse set of techniques including molecular tools, activity tests, and microbial counts in samples taken along 3 years. The recover capacity of the biomass was also studied in a lab-scale reactor operated with intermittent aeration without feeding for 36 days. The results showed that changes in the feeding negatively affected the nitrifying community, but the nitrogen removal efficiencies could be restored after the concentration stress. Species substitution was observed within the nitrifying bacteria, Nitrosomonas europaea and Nitrobacter predominated initially, and after an ammonia overload period, Nitrosomonas nitrosa and Nitrospira became dominant. Some denitrifiers, with nirS related to Alicycliphilus, Azospirillum, and Marinobacter nirS, persisted during long-term reactor operation, but the community fluctuated both in composition and in abundance. This fluctuating community may better resist the continuous changes in the feeding regime. Our results showed that a nitrifying-denitrifying SBR could be operated with low loads or even without feeding during production shut down periods. (orig.)

  5. Immobilization of microbial cell and yeast cell and its application to biomass conversion using radiation techniques

    International Nuclear Information System (INIS)

    Kaetsu, Isao; Kumakura, Minoru; Fujimura, Takashi; Kasai, Noboru; Tamada, Masao

    1987-01-01

    The recent results of immobilization of cellulase-producing cells and ethanol-fermentation yeast by radiation were reported. The enzyme of cellulase produced by immobilized cells was used for saccharification of lignocellulosic wastes and immobilized yeast cells were used for fermentation reaction from glucose to ethanol. The wastes such as chaff and bagasse were treated by γ-ray or electron-beam irradiation in the presence of alkali and subsequent mechanical crushing, to form a fine powder less than 50 μm in diameter. On the other hand, Trichoderma reesei as a cellulase-producing microbial cell was immobilized on a fibrous carrier having a specific porous structure and cultured to produce cellulase. The enzymatic saccharification of the pretreated waste was carried out using the produced cellulase. The enhanced fermentation process to produce ethanol from glucose with the immobilized yeast by radiation was also studied. The ethanol productivity of immobilized growing yeast cells thus obtained was thirteen times that of free yeast cells in a 1:1 volume of liquid medium to immobilized yeast cells. (author)

  6. Immobilization of microbial cell and yeast cell and its application to biomass conversion using radiation techniques

    Science.gov (United States)

    Kaetsu, Isao; Kumakura, Minoru; Fujimura, Takashi; Kasai, Noboru; Tamada, Masao

    The recent results of immobilization of cellulase-producing cells and ethanol-fermentation yeast by radiation were reported. The enzyme of cellulase produced by immobilized cells was used for saccharification of lignocellulosic wastes and immobilized yeast cells were used for fermentation reaction from glucose to ethanol. The wastes such as chaff and bagasse were treated by γ-ray or electron-beam irradiation in the presence of alkali and subsequent mechanical crushing, to form a fine powder less than 50 μm in diameter. On the other hand, Trichoderma reesei as a cellulase-producing microbial cell was immobilized on a fibrous carrier having a specific porous structure and cultured to produce cellulase. The enzymatic saccharification of the pretreated waste was carried out using the produced cellulase. The enhanced fermentation process to produce ethanol from glucose with the immobilized yeast by radiation was also studied. The ethanol productivity of immobilized growing yeast cells thus obtained was thirteen times that of free yeast cells in a 1:1 volume of liquid medium to immobilized yeast cells.

  7. RELATIONSHIPS BETWEEN SOIL MICROBIAL BIOMASS, AGGREGATE STABILITY AND AGGREGATE ASSOCIATED-C: A MECHANISTIC APPROACH

    Directory of Open Access Journals (Sweden)

    Patrizia Guidi

    2014-01-01

    Full Text Available For the identification of C pools involved in soil aggregation, a physically-based aggregate fractionation was proposed, and  additional pretreatments were used in the measurement of the 1-2 mm aggregate stability in order to elucidate the relevance of the role of soil microorganisms with respect to the different aggregate breakdown mechanisms. The study was carried out on three clay loam Regosols, developed on calcareous shales, known history of organic cultivation.Our results showed that the soil C pool controlling the process of stabilisation of aggregates was related to the microbial community. We identified the resistance to fast wetting as the major mechanism of aggregate stability driven by microorganims. The plausible hypothesis is that organic farming promotes fungi growth, improving water repellency of soil aggregates by fungal hydrophobic substances. By contrast, we failed in the identification of C pools controlling the formation of aggregates, probably because of the disturbance of mechanical tillage which contributes to the breakdown of soil aggregates.The physically-based aggregate fractionation proposed in this study resulted useful in the  mechanistically understanding of the role of microorganisms in soil aggregation and it might be suggested for studying the impact of management on C pools, aggregates properties and their relationships in agricultural soils.

  8. Evaluation of alternative approaches for landscape-scale biomass estimation in a mixed-species northern forest

    Science.gov (United States)

    Coeli M. Hoover; Mark J. Ducey; R. Andy Colter; Mariko Yamasaki

    2018-01-01

    There is growing interest in estimating and mapping biomass and carbon content of forests across large landscapes. LiDAR-based inventory methods are increasingly common and have been successfully implemented in multiple forest types. Asner et al. (2011) developed a simple universal forest carbon estimation method for tropical forests that reduces the amount of required...

  9. Integrating field plots, lidar, and landsat time series to provide temporally consistent annual estimates of biomass from 1990 to present

    Science.gov (United States)

    Warren B. Cohen; Hans-Erik Andersen; Sean P. Healey; Gretchen G. Moisen; Todd A. Schroeder; Christopher W. Woodall; Grant M. Domke; Zhiqiang Yang; Robert E. Kennedy; Stephen V. Stehman; Curtis Woodcock; Jim Vogelmann; Zhe Zhu; Chengquan. Huang

    2015-01-01

    We are developing a system that provides temporally consistent biomass estimates for national greenhouse gas inventory reporting to the United Nations Framework Convention on Climate Change. Our model-assisted estimation framework relies on remote sensing to scale from plot measurements to lidar strip samples, to Landsat time series-based maps. As a demonstration, new...

  10. Methods and equations for estimating aboveground volume, biomass, and carbon for trees in the U.S. forest inventory, 2010

    Science.gov (United States)

    Christopher W. Woodall; Linda S. Heath; Grant M. Domke; Michael C. Nichols

    2011-01-01

    The U.S. Forest Service, Forest Inventory and Analysis (FIA) program uses numerous models and associated coefficients to estimate aboveground volume, biomass, and carbon for live and standing dead trees for most tree species in forests of the United States. The tree attribute models are coupled with FIA's national inventory of sampled trees to produce estimates of...

  11. Validation databases for simulation models: aboveground biomass and net primary productive, (NPP) estimation using eastwide FIA data

    Science.gov (United States)

    Jennifer C. Jenkins; Richard A. Birdsey

    2000-01-01

    As interest grows in the role of forest growth in the carbon cycle, and as simulation models are applied to predict future forest productivity at large spatial scales, the need for reliable and field-based data for evaluation of model estimates is clear. We created estimates of potential forest biomass and annual aboveground production for the Chesapeake Bay watershed...

  12. Statistical properties of mean stand biomass estimators in a LIDAR-based double sampling forest survey design.

    Science.gov (United States)

    H.E. Anderson; J. Breidenbach

    2007-01-01

    Airborne laser scanning (LIDAR) can be a valuable tool in double-sampling forest survey designs. LIDAR-derived forest structure metrics are often highly correlated with important forest inventory variables, such as mean stand biomass, and LIDAR-based synthetic regression estimators have the potential to be highly efficient compared to single-stage estimators, which...

  13. Estimation of black carbon content for biomass burning aerosols from multi-channel Raman lidar data

    Science.gov (United States)

    Talianu, Camelia; Marmureanu, Luminita; Nicolae, Doina

    2015-04-01

    Biomass burning due to natural processes (forest fires) or anthropical activities (agriculture, thermal power stations, domestic heating) is an important source of aerosols with a high content of carbon components (black carbon and organic carbon). Multi-channel Raman lidars provide information on the spectral dependence of the backscatter and extinction coefficients, embedding information on the black carbon content. Aerosols with a high content of black carbon have large extinction coefficients and small backscatter coefficients (strong absorption), while aerosols with high content of organic carbon have large backscatter coefficients (weak absorption). This paper presents a method based on radiative calculations to estimate the black carbon content of biomass burning aerosols from 3b+2a+1d lidar signals. Data is collected at Magurele, Romania, at the cross-road of air masses coming from Ukraine, Russia and Greece, where burning events are frequent during both cold and hot seasons. Aerosols are transported in the free troposphere, generally in the 2-4 km altitude range, and reaches the lidar location after 2-3 days. Optical data are collected between 2011-2012 by a multi-channel Raman lidar and follows the quality assurance program of EARLINET. Radiative calculations are made with libRadTran, an open source radiative model developed by ESA. Validation of the retrievals is made by comparison to a co-located C-ToF Aerosol Mass Spectrometer. Keywords: Lidar, aerosols, biomass burning, radiative model, black carbon Acknowledgment: This work has been supported by grants of the Romanian National Authority for Scientific Research, Programme for Research- Space Technology and Advanced Research - STAR, project no. 39/2012 - SIAFIM, and by Romanian Partnerships in priority areas PNII implemented with MEN-UEFISCDI support, project no. 309/2014 - MOBBE

  14. Optimal Atmospheric Correction for Above-Ground Forest Biomass Estimation with the ETM+ Remote Sensor.

    Science.gov (United States)

    Nguyen, Hieu Cong; Jung, Jaehoon; Lee, Jungbin; Choi, Sung-Uk; Hong, Suk-Young; Heo, Joon

    2015-07-31

    The reflectance of the Earth's surface is significantly influenced by atmospheric conditions such as water vapor content and aerosols. Particularly, the absorption and scattering effects become stronger when the target features are non-bright objects, such as in aqueous or vegetated areas. For any remote-sensing approach, atmospheric correction is thus required to minimize those effects and to convert digital number (DN) values to surface reflectance. The main aim of this study was to test the three most popular atmospheric correction models, namely (1) Dark Object Subtraction (DOS); (2) Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) and (3) the Second Simulation of Satellite Signal in the Solar Spectrum (6S) and compare them with Top of Atmospheric (TOA) reflectance. By using the k-Nearest Neighbor (kNN) algorithm, a series of experiments were conducted for above-ground forest biomass (AGB) estimations of the Gongju and Sejong region of South Korea, in order to check the effectiveness of atmospheric correction methods for Landsat ETM+. Overall, in the forest biomass estimation, the 6S model showed the bestRMSE's, followed by FLAASH, DOS and TOA. In addition, a significant improvement of RMSE by 6S was found with images when the study site had higher total water vapor and temperature levels. Moreover, we also tested the sensitivity of the atmospheric correction methods to each of the Landsat ETM+ bands. The results confirmed that 6S dominates the other methods, especially in the infrared wavelengths covering the pivotal bands for forest applications. Finally, we suggest that the 6S model, integrating water vapor and aerosol optical depth derived from MODIS products, is better suited for AGB estimation based on optical remote-sensing data, especially when using satellite images acquired in the summer during full canopy development.

  15. Forest Aboveground Biomass Mapping and Canopy Cover Estimation from Simulated ICESat-2 Data

    Science.gov (United States)

    Narine, L.; Popescu, S. C.; Neuenschwander, A. L.

    2017-12-01

    The assessment of forest aboveground biomass (AGB) can contribute to reducing uncertainties associated with the amount and distribution of terrestrial carbon. With a planned launch date of July 2018, the Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) will provide data which will offer the possibility of mapping AGB at global scales. In this study, we develop approaches for utilizing vegetation data that will be delivered in ICESat-2's land-vegetation along track product (ATL08). The specific objectives are to: (1) simulate ICESat-2 photon-counting lidar (PCL) data using airborne lidar data, (2) utilize simulated PCL data to estimate forest canopy cover and AGB and, (3) upscale AGB predictions to create a wall-to-wall AGB map at 30-m spatial resolution. Using existing airborne lidar data for Sam Houston National Forest (SHNF) located in southeastern Texas and known ICESat-2 beam locations, PCL data are simulated from discrete return lidar points. We use multiple linear regression models to relate simulated PCL metrics for 100 m segments along the ICESat-2 ground tracks to AGB from a biomass map developed using airborne lidar data and canopy cover calculated from the same. Random Forest is then used to create an AGB map from predicted estimates and explanatory data consisting of spectral metrics derived from Landsat TM imagery and land cover data from the National Land Cover Database (NLCD). Findings from this study will demonstrate how data that will be acquired by ICESat-2 can be used to estimate forest structure and characterize the spatial distribution of AGB.

  16. Microbial biomass, community structure and metal tolerance of a naturally Pb-enriched forest soil.

    Science.gov (United States)

    Bååth, E; Díaz-Raviña, M; Bakken, L R

    2005-11-01

    The effect of long-term elevated soil Pb levels on soil microbiota was studied at a forest site in Norway, where the soil has been severely contaminated with Pb since the last period of glaciation (several thousand years). Up to 10% Pb (total amount, w/w) has been found in the top layer. The microbial community was drastically affected, as judged from changes in the phospholipid fatty acid (PLFA) pattern. Specific PLFAs that were high in Pb-enriched soil were branched (especially br17:0 and br18:0), whereas PLFAs common in eukaryotic organisms such as fungi (18:2omega6,9 and 20:4) were low compared with levels at adjacent, uncontaminated sites. Congruent changes in the PLFA pattern were found upon analyzing the culturable part of the bacterial community. The high Pb concentrations in the soil resulted in increased tolerance to Pb of the bacterial community, measured using both thymidine incorporation and plate counts. Furthermore, changes in tolerance were correlated to changes in the community structure. The bacterial community of the most contaminated soils showed higher specific activity (thymidine and leucine incorporation rates) and higher culturability than that of control soils. Fungal colony forming units (CFUs) were 10 times lower in the most Pb-enriched soils, the species composition was widely different from that in control soils, and the isolated fungi had high Pb tolerance. The most commonly isolated fungus in Pb-enriched soils was Tolypocladium inflatum. Comparison of isolates from Pb-enriched soil and isolates from unpolluted soils showed that T. inflatum was intrinsically Pb-tolerant, and that the prolonged conditions with high Pb had not selected for any increased tolerance.

  17. A Model of the Effect of the Microbial Biomass on the Isotherm of the Fermenting Solids in Solid-State Fermentation

    Directory of Open Access Journals (Sweden)

    Barbara Celuppi Marques

    2006-01-01

    Full Text Available We compare isotherms for soybeans and soybeans fermented with Rhizopus oryzae, showing that in solid-state fermentation the biomass affects the isotherm of the fermenting solids. Equations are developed to calculate, for a given overall water content of the fermenting solids, the water contents of the biomass and residual substrate, as well as the water activity. A case study, undertaken using a mathematical model of a well-mixed bioreactor, shows that if water additions are made on the basis of the assumption that fermenting solids have the same isotherm as the substrate itself, poor growth can result since the added water does not maintain the water activity at levels favorable for growth. We conclude that the effect of the microbial biomass on the isotherm of the fermenting solids must be taken into account in mathematical models of solid-state fermentation bioreactors.

  18. Effects of lead contamination on soil enzymatic activities, microbial biomass, and rice physiological indices in soil-lead-rice (Oryza sativa L.) system.

    Science.gov (United States)

    Zeng, Lu S; Liao, Min; Chen, Cheng L; Huang, Chang Y

    2007-05-01

    The effect of lead (Pb) treatment on the soil enzymatic activities, soil microbial biomass, rice physiological indices and rice biomass were studied in a greenhouse pot experiment. Six levels of Pb viz. 0(CK), 100, 300, 500, 700, 900 mg/kg soil were applied in two types of paddy soils. The results showed that Pb treatment had a stimulating effect on soil enzymatic activities and microbial biomass carbon (Cmic) at low concentration and an inhibitory influence at higher concentration. The degree of influence on enzymatic activities and Cmic by Pb was related to the clay and organic matter contents of the soils. When the Pb treatment was raised to the level of 500 mg/kg, ecological risk appeared both to soil microorganisms and plants. The results also revealed a consistent trend of increased chlorophyll contents and rice biomass initially, maximum at a certain Pb treatment, and then decreased gradually with the increase in Pb concentration. Pb was effective in inducing proline accumulation and its toxicity causes oxidative stress in rice plants. Therefore, it was concluded that soil enzymatic activities, Cmic and rice physiological indices, could be sensitive indicators to reflect environmental stress in soil-lead-rice system.

  19. Impact of biomass burning on urban air quality estimated by organic tracers: Guangzhou and Beijing as cases

    Energy Technology Data Exchange (ETDEWEB)

    Qiaoqiao Wang; Min Shao; Ying Liu [State Joint Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences, Peking University, Beijing 100871, (China); Kuster, William; Goldan, Paul [Earth System Research Laboratory, U.S. Department of Commerce, Boulder, CO 80305, (United States); Xiaohua Li; Yuan Liu; Sihua Lu [State Joint Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences, Peking University, Beijing 100871, (China)

    2007-12-15

    The impacts of biomass burning have not been adequately studied in China. In this work, chemical compositions of volatile organic compounds and particulate organic matters were measured in August 2005 in Beijing and in October 2004 in Guangzhou city. The performance of several possible tracers for biomass burning is compared by using acetonitrile as a reference compound. The correlations between the possible tracers and acetonitrile show that the use of K{sup +} as a tracer could result in bias because of the existence of other K+ sources in urban areas, while chloromethane is not reliable due to its wide use as industrial chemical. The impact of biomass burning on air quality is estimated using acetonitrile and levoglucosan as tracers. The results show that the impact of biomass burning is ubiquitous in both suburban and urban Guangzhou, and the frequencies of air pollution episodes significantly influenced by biomass burning were 100% for Xinken and 58% for downtown Guangzhou city. Fortunately, the air quality in only 2 out of 22 days was partly impacted by biomass burning in August in Beijing, the month that 2008 Olympic games will take place. The quantitative contribution of biomass burning to ambient PM{sub 2.5} concentrations in Guangzhou city was also estimated by the ratio of levoglocusan to PM{sub 2.5} in both the ambient air and biomass burning plumes. The results show that biomass burning contributes 3.02013;16.8% and 4.02013;19.0% of PM{sub 2.5} concentrations in Xinken and Guangzhou downtown, respectively. (Author)

  20. Impact of biomass burning on urban air quality estimated by organic tracers: Guangzhou and Beijing as cases

    Energy Technology Data Exchange (ETDEWEB)

    Qiaoqiao Wang; Min Shao; Ying Liu [State Joint Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences, Peking University, Beijing 100871, (China); Kuster, William; Goldan, Paul [Earth System Research Laboratory, U.S. Department of Commerce, Boulder, CO 80305, (United States); Xiaohua Li; Yuan Liu; Sihua Lu [State Joint Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences, Peking University, Beijing 100871, (China)

    2007-12-15

    The impacts of biomass burning have not been adequately studied in China. In this work, chemical compositions of volatile organic compounds and particulate organic matters were measured in August 2005 in Beijing and in October 2004 in Guangzhou city. The performance of several possible tracers for biomass burning is compared by using acetonitrile as a reference compound. The correlations between the possible tracers and acetonitrile show that the use of K{sup +} as a tracer could result in bias because of the existence of other K+ sources in urban areas, while chloromethane is not reliable due to its wide use as industrial chemical. The impact of biomass burning on air quality is estimated using acetonitrile and levoglucosan as tracers. The results show that the impact of biomass burning is ubiquitous in both suburban and urban Guangzhou, and the frequencies of air pollution episodes significantly influenced by biomass burning were 100% for Xinken and 58% for downtown Guangzhou city. Fortunately, the air quality in only 2 out of 22 days was partly impacted by biomass burning in August in Beijing, the month that 2008 Olympic games will take place. The quantitative contribution of biomass burning to ambient PM{sub 2.5} concentrations in Guangzhou city was also estimated by the ratio of levoglocusan to PM{sub 2.5} in both the ambient air and biomass burning plumes. The results show that biomass burning contributes 3.02013;16.8% and 4.02013;19.0% of PM{sub 2.5} concentrations in Xinken and Guangzhou downtown, respectively. (Author).

  1. Reduced biomass burning emissions reconcile conflicting estimates of the post-2006 atmospheric methane budget.

    Science.gov (United States)

    Worden, John R; Bloom, A Anthony; Pandey, Sudhanshu; Jiang, Zhe; Worden, Helen M; Walker, Thomas W; Houweling, Sander; Röckmann, Thomas

    2017-12-20

    Several viable but conflicting explanations have been proposed to explain the recent ~8 p.p.b. per year increase in atmospheric methane after 2006, equivalent to net emissions increase of ~25 Tg CH 4 per year. A concurrent increase in atmospheric ethane implicates a fossil source; a concurrent decrease in the heavy isotope content of methane points toward a biogenic source, while other studies propose a decrease in the chemical sink (OH). Here we show that biomass burning emissions of methane decreased by 3.7 (±1.4) Tg CH 4 per year from the 2001-2007 to the 2008-2014 time periods using satellite measurements of CO and CH 4 , nearly twice the decrease expected from prior estimates. After updating both the total and isotopic budgets for atmospheric methane with these revised biomass burning emissions (and assuming no change to the chemical sink), we find that fossil fuels contribute between 12-19 Tg CH 4 per year to the recent atmospheric methane increase, thus reconciling the isotopic- and ethane-based results.

  2. Geostationary satellite estimation of biomass burning in Amazonia during BASE-A

    International Nuclear Information System (INIS)

    Menzel, W.P.; Cutrim, E.C.; Prins, E.M.

    1991-01-01

    This chapter presents the results of using Geostationary Operational Environmental Satellite (GOES) Visible Infrared Spin Scan Radiometer Atmospheric Sounder (VAS) infrared window (3.9 and 11.2 microns) data to monitor biomass burning several times per day in Amazonia. The technique of Matson and Dozier using two window channels was adapted to GOES VAS infrared data to estimate the size and temperature of fires associated with deforestation in the vicinity of Alta Floresta, Brazil, during the Biomass Burning Airborne and Spaceborne Experiment - Amazonia (BASE-A). Although VAS data do not offer the spatial resolution available with AVHRR data 97 km versus 1 km, respectively, this decreased resolution does not seem to hinder the ability of the VAS instrument to detect fires; in some cases it proves to be advantageous in that saturation does not occur as often. VAS visible data are additionally helpful in verifying that the hot spots sensed in the infrared are actually related to fires. Furthermore, the fire plumes can be tracked in time to determine their motion and extent. In this way, the GOES satellite offers a unique ability to monitor diurnal variations in fire activity and transport of related aerosols

  3. Dynamics of microbial biomass and respiratory activity during late summer in a site of Arctic Kongsfjorden

    Directory of Open Access Journals (Sweden)

    Rosabruna La Ferla

    2014-06-01

    The Kongsfjorden was affected by inflow of Atlantic water as well as glacier melt water runoff (Cottier et al., 2005. The experiment comprised 5 samplings performed during a 7 day period in MDI station. For each sampling, photosynthetically active radiation (PAR, temperature and conductivity (salinity were recorded along the water column with a PNF-300 profiler and a SeaBird Electronics SBE-911 plus profiler, respectively . Water samples were taken at five different depths (surface, 5, 25, 50 and 100 m to determine nutrients, particulate organic carbon, prokaryotes and phytoplankton biomass, and community respiration. In addition, prokaryotes sunk with the particulate matter were studied into the sediment trap positioned in the MDI during the period between June and September 2013. The latter assessment allowed us to determine the flow of prokaryotes, conveyed from organic matter sinking, throughout the summer. Due to melting of the glaciers in the surface water of the study site, there were sediment loads which strongly limited light penetration and low irradiance (~0.7% E0+ at 5 meters below the surface. Along the water column the intrusion of the salty and warm Atlantic water was visible in the study site and the warm core was at about 25 m depth. PO4 concentrations ranged between 0.43 (surface and 1 µM (100 m and in general the values increased from surface to bottom. NH4, NO2 and NO3 significantly changed along the vertical and with time and varied between 0.39 and 5.05µM, 0.01 and 0.67µM, 0.001 and 4.18µM, respectively. Prokaryotic abundances and cell volumes ranged between 5.6 and 15.9 E+05 cells ml-1 and 0.033 and 0.093 µm3, respectively. These latter parameters showed a peak at 25 m depth in the core of incoming Atlantic water. This evidence was not determined in chlorophyll a (range 0.034-1.102 mg m-3, where the highest values were determined at the surface and 5 m depth. Speculations will be made on the variability of the fluxes of carbon

  4. A generic model for estimating biomass accumulation and greenhouse gas emissions from perennial crops

    Science.gov (United States)

    Ledo, Alicia; Heathcote, Richard; Hastings, Astley; Smith, Pete; Hillier, Jonathan

    2017-04-01

    -models presented in this paper can be parametrized for different crops. Quantifying CO2 capture by plants and biomass accumulation and changes in soil carbon, are key in evaluating the impacts of perennial crops in life cycle analysis. We then use this model to illustrate the importance of biomass in the overall GHG estimation from four important perennial crops - sugarcane, Miscanthus, coffee, and apples - which were chosen to cover tropical and temperate regions, trees and grasses, and energy and food supply.

  5. Estimation of microbial protein supply in ruminants using urinary purine derivatives

    International Nuclear Information System (INIS)

    Makkar, H.P.S.; Chen, X.B.

    2004-01-01

    This publication presents various models, describing the quantitative excretion of purine derivatives in urine, developed for various breeds of cattle and for sheep, goat, camel and buffalo and their use for estimation of microbial protein supply in ruminant livestock. It also describes progress made over the last decade in analytical methods for determining purine derivatives, and a unique approach for estimating microbial protein supply using spot urine samples developed under the FAO/IAEA CRP. This approach of using spot urine samples dispenses with quantitative recovery of urine, enabling its use by field and extension workers for evaluation of the nutritional status of farm animals. Future areas of research are also highlighted in the book. This book is a good source of reference for research workers, students and extension workers alike

  6. Estimation of aboveground biomass in Mediterranean forests by statistical modelling of ASTER fraction images

    Science.gov (United States)

    Fernández-Manso, O.; Fernández-Manso, A.; Quintano, C.

    2014-09-01

    Aboveground biomass (AGB) estimation from optical satellite data is usually based on regression models of original or synthetic bands. To overcome the poor relation between AGB and spectral bands due to mixed-pixels when a medium spatial resolution sensor is considered, we propose to base the AGB estimation on fraction images from Linear Spectral Mixture Analysis (LSMA). Our study area is a managed Mediterranean pine woodland (Pinus pinaster Ait.) in central Spain. A total of 1033 circular field plots were used to estimate AGB from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) optical data. We applied Pearson correlation statistics and stepwise multiple regression to identify suitable predictors from the set of variables of original bands, fraction imagery, Normalized Difference Vegetation Index and Tasselled Cap components. Four linear models and one nonlinear model were tested. A linear combination of ASTER band 2 (red, 0.630-0.690 μm), band 8 (short wave infrared 5, 2.295-2.365 μm) and green vegetation fraction (from LSMA) was the best AGB predictor (Radj2=0.632, the root-mean-squared error of estimated AGB was 13.3 Mg ha-1 (or 37.7%), resulting from cross-validation), rather than other combinations of the above cited independent variables. Results indicated that using ASTER fraction images in regression models improves the AGB estimation in Mediterranean pine forests. The spatial distribution of the estimated AGB, based on a multiple linear regression model, may be used as baseline information for forest managers in future studies, such as quantifying the regional carbon budget, fuel accumulation or monitoring of management practices.

  7. Comparison of Two Mechanistic Microbial Growth Models to Estimate Shelf Life of Perishable Food Package under Dynamic Temperature Conditions

    Directory of Open Access Journals (Sweden)

    Dong Sun Lee

    2014-01-01

    Full Text Available Two mechanistic microbial growth models (Huang’s model and model of Baranyi and Roberts given in differential and integrated equation forms were compared in predicting the microbial growth and shelf life under dynamic temperature storage and distribution conditions. Literatures consistently reporting the microbial growth data under constant and changing temperature conditions were selected to obtain the primary model parameters, set up the secondary models, and apply them to predict the microbial growth and shelf life under fluctuating temperatures. When evaluated by general estimation behavior, bias factor, accuracy factor, and root-mean-square error, Huang’s model was comparable to Baranyi and Roberts’ model in the capability to estimate microbial growth under dynamic temperature conditions. Its simple form of single differential equation incorporating directly the growth rate and lag time may work as an advantage to be used in online shelf life estimation by using the electronic device.

  8. Estimating Stand Volume and Above-Ground Biomass of Urban Forests Using LiDAR

    Directory of Open Access Journals (Sweden)

    Vincenzo Giannico

    2016-04-01

    Full Text Available Assessing forest stand conditions in urban and peri-urban areas is essential to support ecosystem service planning and management, as most of the ecosystem services provided are a consequence of forest stand characteristics. However, collecting data for assessing forest stand conditions is time consuming and labor intensive. A plausible approach for addressing this issue is to establish a relationship between in situ measurements of stand characteristics and data from airborne laser scanning (LiDAR. In this study we assessed forest stand volume and above-ground biomass (AGB in a broadleaved urban forest, using a combination of LiDAR-derived metrics, which takes the form of a forest allometric model. We tested various methods for extracting proxies of basal area (BA and mean stand height (H from the LiDAR point-cloud distribution and evaluated the performance of different models in estimating forest stand volume and AGB. The best predictors for both models were the scale parameters of the Weibull distribution of all returns (except the first (proxy of BA and the 95th percentile of the distribution of all first returns (proxy of H. The R2 were 0.81 (p < 0.01 for the stand volume model and 0.77 (p < 0.01 for the AGB model with a RMSE of 23.66 m3·ha−1 (23.3% and 19.59 Mg·ha−1 (23.9%, respectively. We found that a combination of two LiDAR-derived variables (i.e., proxy of BA and proxy of H, which take the form of a forest allometric model, can be used to estimate stand volume and above-ground biomass in broadleaved urban forest areas. Our results can be compared to other studies conducted using LiDAR in broadleaved forests with similar methods.

  9. Performance of five surface energy balance models for estimating daily evapotranspiration in high biomass sorghum

    Science.gov (United States)

    Wagle, Pradeep; Bhattarai, Nishan; Gowda, Prasanna H.; Kakani, Vijaya G.

    2017-06-01

    Robust evapotranspiration (ET) models are required to predict water usage in a variety of terrestrial ecosystems under different geographical and agrometeorological conditions. As a result, several remote sensing-based surface energy balance (SEB) models have been developed to estimate ET over large regions. However, comparison of the performance of several SEB models at the same site is limited. In addition, none of the SEB models have been evaluated for their ability to predict ET in rain-fed high biomass sorghum grown for biofuel production. In this paper, we evaluated the performance of five widely used single-source SEB models, namely Surface Energy Balance Algorithm for Land (SEBAL), Mapping ET with Internalized Calibration (METRIC), Surface Energy Balance System (SEBS), Simplified Surface Energy Balance Index (S-SEBI), and operational Simplified Surface Energy Balance (SSEBop), for estimating ET over a high biomass sorghum field during the 2012 and 2013 growing seasons. The predicted ET values were compared against eddy covariance (EC) measured ET (ETEC) for 19 cloud-free Landsat image. In general, S-SEBI, SEBAL, and SEBS performed reasonably well for the study period, while METRIC and SSEBop performed poorly. All SEB models substantially overestimated ET under extremely dry conditions as they underestimated sensible heat (H) and overestimated latent heat (LE) fluxes under dry conditions during the partitioning of available energy. METRIC, SEBAL, and SEBS overestimated LE regardless of wet or dry periods. Consequently, predicted seasonal cumulative ET by METRIC, SEBAL, and SEBS were higher than seasonal cumulative ETEC in both seasons. In contrast, S-SEBI and SSEBop substantially underestimated ET under too wet conditions, and predicted seasonal cumulative ET by S-SEBI and SSEBop were lower than seasonal cumulative ETEC in the relatively wetter 2013 growing season. Our results indicate the necessity of inclusion of soil moisture or plant water stress

  10. Estimating microalgae Synechococcus nidulans daily biomass concentration using neuro-fuzzy network

    Directory of Open Access Journals (Sweden)

    Vitor Badiale Furlong

    2013-02-01

    Full Text Available In this study, a neuro-fuzzy estimator was developed for the estimation of biomass concentration of the microalgae Synechococcus nidulans from initial batch concentrations, aiming to predict daily productivity. Nine replica experiments were performed. The growth was monitored daily through the culture medium optic density and kept constant up to the end of the exponential phase. The network training followed a full 3³ factorial design, in which the factors were the number of days in the entry vector (3,5 and 7 days, number of clusters (10, 30 and 50 clusters and internal weight softening parameter (Sigma (0.30, 0.45 and 0.60. These factors were confronted with the sum of the quadratic error in the validations. The validations had 24 (A and 18 (B days of culture growth. The validations demonstrated that in long-term experiments (Validation A the use of a few clusters and high Sigma is necessary. However, in short-term experiments (Validation B, Sigma did not influence the result. The optimum point occurred within 3 days in the entry vector, 10 clusters and 0.60 Sigma and the mean determination coefficient was 0.95. The neuro-fuzzy estimator proved a credible alternative to predict the microalgae growth.

  11. Compatible above-ground biomass equations and carbon stock estimation for small diameter Turkish pine (Pinus brutia Ten.).

    Science.gov (United States)

    Sakici, Oytun Emre; Kucuk, Omer; Ashraf, Muhammad Irfan

    2018-04-15

    Small trees and saplings are important for forest management, carbon stock estimation, ecological modeling, and fire management planning. Turkish pine (Pinus brutia Ten.) is a common coniferous species and comprises 25.1% of total forest area of Turkey. Turkish pine is also important due to its flammable fuel characteristics. In this study, compatible above-ground biomass equations were developed to predict needle, branch, stem wood, and above-ground total biomass, and carbon stock assessment was also described for Turkish pine which is smaller than 8 cm diameter at breast height or shorter than breast height. Compatible biomass equations are useful for biomass prediction of small diameter individuals of Turkish pine. These equations will also be helpful in determining fire behavior characteristics and calculating their carbon stock. Overall, present study will be useful for developing ecological models, forest management plans, silvicultural plans, and fire management plans.

  12. Soil microbial biomass in organic farming system Biomassa microbiana do solo em sistemas orgânicos

    Directory of Open Access Journals (Sweden)

    Ademir Sérgio Ferreira de Araújo

    2010-11-01

    Full Text Available Agricultural production systems have to combine management practices in order to sustain soil's profitability and quality. Organic farming is gaining worldwide acceptance and has been expanding at an annual rate of 20% in the last decade, accounting for over 24 million hectares worldwide. Organic practices avoid applications of synthetic fertilizers and pesticides, rely on organic inputs and recycling for nutrient supply, and emphasize cropping system design and biological processes for pest management, as defined by organic farming regulation in the world. In comparison with conventional farming, organic farming has potential benefits in improving food quality and safety. Plant production in organic farming mainly depends on nutrient release as a function of mineralization processes in soils. The build-up of a large and active soil microbial biomass is important pool of accessible nutrients, therefore, is an important priority in organic farming. In organic farming, there is positive effect of quantity and quality of inputs of organic residues on soil microbial biomass. In this way, the organic systems are extremely important for the increase of the soil fertility and the maintenance of the environmental sustainability.A produção agrícola tem de combinar práticas para prover a sustentabilidade do solo. A agricultura orgânica está ganhando aceitação mundial e cresce à taxa anual de 20% na última década, contabilizando mais de 24 milhões de hectares. As práticas orgânicas evitam o uso de fertilizantes sintéticos e pesticidas, enfatiza a aplicação de matéria orgânica, como também a reciclagem de nutrientes e de processos biológicos para manejo de pragas, através das regras dos sistemas orgânicos no mundo. Em comparação com a agricultura convencional, os sistemas orgânicos têm potencial de melhorar a qualidade e a segurança dos alimentos. A produção das plantas no sistema orgânico depende da liberação de nutrientes

  13. Biochar amendment decreases soil microbial biomass and increases bacterial diversity in Moso bamboo (Phyllostachys edulis) plantations under simulated nitrogen deposition

    Science.gov (United States)

    Li, Quan; Lei, Zhaofeng; Song, Xinzhang; Zhang, Zhiting; Ying, Yeqing; Peng, Changhui

    2018-04-01

    Biochar amendment has been proposed as a strategy to improve acidic soils after overuse of nitrogen fertilizers. However, little is known of the role of biochar in soil microbial biomass carbon (MBC) and bacterial community structure and diversity after soil acidification induced by nitrogen (N) deposition. Using high-throughput sequencing of the 16S rRNA gene, we determined the effects of biochar amendment (BC0, 0 t bamboo biochar ha‑1 BC20, 20 t bamboo biochar ha‑1 and BC40, 40 t bamboo biochar ha‑1) on the soil bacterial community structure and diversity in Moso bamboo plantations that had received simulated N deposition (N30, 30 kg N ha‑1 yr‑1 N60, 60 kg N ha‑1 yr‑1 N90, 90 kg N ha‑1 yr‑1 and N-free) for 21 months. After treatment of N-free plots, BC20 significantly increased soil MBC and bacterial diversity, while BC40 significantly decreased soil MBC but increased bacterial diversity. When used to amend N30 and N60 plots, biochar significantly decreased soil MBC and the reducing effect increased with biochar amendment amount. However, these significant effects were not observed in N90 plots. Under N deposition, biochar amendment largely increased soil bacterial diversity, and these effects depended on the rates of N deposition and biochar amendment. Soil bacterial diversity was significantly related to the soil C/N ratio, pH, and soil organic carbon content. These findings suggest an optimal approach for using biochar to offset the effects of N deposition in plantation soils and provide a new perspective for understanding the potential role of biochar amendments in plantation soil.

  14. Allometric Equations for Estimating Biomass and Carbon Stocks in the Temperate Forests of North-Western Mexico

    Directory of Open Access Journals (Sweden)

    Benedicto Vargas-Larreta

    2017-07-01

    Full Text Available This paper presents new equations for estimating above-ground biomass (AGB and biomass components of seventeen forest species in the temperate forests of northwestern Mexico. A data set corresponding to 1336 destructively sampled oak and pine trees was used to fit the models. The generalized method of moments was used to simultaneously fit systems of equations for biomass components and AGB, to ensure additivity. In addition, the carbon content of each tree component was calculated by the dry combustion method, in a TOC analyser. The results of cross-validation indicated that the fitted equations accounted for on average 91%, 82%, 83% and 76% of the observed variance in stem wood and stem bark, branch and foliage biomass, respectively, whereas the total AGB equations explained on average 93% of the total observed variance in AGB. The inclusion of total height (h or diameter at breast height2 × total height (d2h as a predictor in the d-only based equations systems slightly improved estimates for stem wood, stem bark and total above-ground biomass, and greatly improved the estimates produced by the branch and foliage biomass equations. The predictive power of the proposed equations is higher than that of existing models for the study area. The fitted equations were used to estimate stand level AGB stocks from data on growing stock in 429 permanent sampling plots. Three machine-learning techniques were used to model the estimated stand level AGB and carbon contents; the selected models were used to map the AGB and carbon distributions in the study area, for which mean values of respectively 129.84 Mg ha−1 and 63.80 Mg ha−1 were obtained.

  15. Sedimentary organic biomarkers suggest detrimental effects of PAHs on estuarine microbial biomass during the 20th century in San Francisco Bay, CA, USA

    Science.gov (United States)

    Nilsen, Elena B.; Rosenbauer, Robert J.; Fuller, Christopher C.; Jaffe, Bruce E.

    2014-01-01

    Hydrocarbon contaminants are ubiquitous in urban aquatic ecosystems, and the ability of some microbial strains to degrade certain polycyclic aromatic hydrocarbons (PAHs) is well established. However, detrimental effects of petroleum hydrocarbon contamination on nondegrader microbial populations and photosynthetic organisms have not often been considered. In the current study, fatty acid methyl ester (FAME) biomarkers in the sediment record were used to assess historical impacts of petroleum contamination on microbial and/or algal biomass in South San Francisco Bay, CA, USA. Profiles of saturated, branched, and monounsaturated fatty acids had similar concentrations and patterns downcore. Total PAHs in a sediment core were on average greater than 20× higher above ∼200 cm than below, which corresponds roughly to the year 1900. Isomer ratios were consistent with a predominant petroleum combustion source for PAHs. Several individual PAHs exceeded sediment quality screening values. Negative correlations between petroleum contaminants and microbial and algal biomarkers – along with high trans/cis ratios of unsaturated FA, and principle component analysis of the PAH and fatty acid records – suggest a negative impacts of petroleum contamination, appearing early in the 20th century, on microbial and/or algal ecology at the site.

  16. Assessing the Effect of Prometryn Soil Residue on Soil Microbial Biomass and Different Crops using Bioassay Test

    Directory of Open Access Journals (Sweden)

    mohamad taghi alebrahim

    2016-09-01

    after germination. The pots were kept for 30 days under controlled conditions. Shoot and root biomass production was measured 30 days after emergence. At harvest, growth parameters including the dry weight of shoots and roots were determined. The data were subjected to analysis of variance by computer facilities, using Mstatc software. Plant response to prometryn residues was fitted with sigmoidal 3 and 4 parametric equations to the shoot biomass data as a function of the herbicide residue concentrations and was used to calculate the doses for 50% inhibition of shoot growth (ED50. In another experiment the effect of prometryn concentrations (0, 0.0033, 0.0166, 0.033, 0.066, 0.1 and 0.166 mg. kg-1soil on soil microbial activity was determined using titration method in controlled conditions. Results and Discussion: Plant response to increasing concentration of prometryn, in general, followed a classical dose response relationship. The logistic model fitted well to the root and shoot plants response herbicide concentrations. Results showed that the shoot and root dry matter were significantly affected by increasing prometryn soil residue in all crops (plettuce>beet>barely. Based on the mechanism of action of prometryn and its best efficiency on board leaf plants control, the least biomass reduction obtained for barley is understandable. In general, this is safe to plant a susceptible species if the plant-available residue were less than the species ED10 value, and there would be a great risk for different levels of crop damage if the plant-available residue were higher than ED50 values of the species. Comparisons between species allow the safe selection of a crop that has a critical ED50 level lower than the residue level in the soil. Alternatively, planting a sensitive species could be delayed until the residue level in the soil is less than the critical level. In the Southwest areas of Iran, these crops are often sown few months after the application of a residual

  17. Floristic, structural, and allometric equations to estimate arboreal volume and biomass in a cerradão site

    Directory of Open Access Journals (Sweden)

    Eder Pereira Miguel

    2017-08-01

    Full Text Available This objective of this study was to characterize the floristic, structural, and ecological groups and to estimate the arboreal volume and biomass of a cerradão site in Palmas, Tocantins, Brazil. A forest inventory was conducted on 10.15 ha of the study area. Plots of 400-m2 were used for systematic sampling. All standing trees (dead or alive with a breast-height diameter (DHB greater than 5 cm were identified and measured. Floristic diversity and horizontal structure were assessed using the Shannon and importance value indices, respectively. Forest vertical structure was classified into three stratata and the tree species were categorized into ecological groups. Ninety tree volumes were rigorously cubed and weighed. Fresh- and dry biomass were sampled and estimated. Mathematical models were applied and adjusted to estimate tree volume and biomass. It was observed that the species Myrcia splendens and Emmotum nitens and the families Fabaceae and Chrysobalanaceae were dominant in our study site. The pioneer (613 individuals ha-1 and climax (530 individuals ha-1 tree species group predominated. The floristic diversity index was estimated as 3.35 nats ind- 1. The vertical structure analysis indicated fewer individuals in the superior stratum (13% compared to the medium (63% and inferior (24% stratum. The Schumacher and Hall model showed better results with regard to estimated forest production. Forest volume and biomass estimates were 126.71 m³ ha-1 and 61.67 Mg ha-1, respectively. The studied cerradão area had high floristic diversity and climax species predominated. Since this cerradão is in close proximity to the Amazon biome, its volume and biomass stocks were higher than those estimated for other cerradão and forest formations within the Cerrado biome.

  18. Estimate of the dry branches biomass in plantations of Pinus maestrensis Bisse in the Granma province, Cuba

    Directory of Open Access Journals (Sweden)

    Hector Barrero-Medel

    2015-06-01

    Full Text Available This study aimed to estimate the biomass of dry branches of Pinus plantations maestrensis Bisse inGranma province. To which 138 trees were felled types selected from the execution of a simple random sample of 40 stands; which were pruned and defoliated, carrying out weighing separately biomass branches of each of the same, determined from the moisture content of representative samples of the branches taken at random and dried in stove at 105 ° C until bring to constant weight, and then convert the values to dry weight. To estimate biomass of dry branches four regression models, where the model presented better goodness of fit was logarithmic, with coefficient of determination and adjusted coefficient of determination of 94.4 and 94.3%, highly significant parameters were evaluated (P 0.001 and lower index value Furnival.

  19. Estimating Aboveground Biomass and Carbon Stocks in Periurban Andean Secondary Forests Using Very High Resolution Imagery

    Directory of Open Access Journals (Sweden)

    Nicola Clerici

    2016-07-01

    Full Text Available Periurban forests are key to offsetting anthropogenic carbon emissions, but they are under constant threat from urbanization. In particular, secondary Neotropical forest types in Andean periurban areas have a high potential to store carbon, but are currently poorly characterized. To address this lack of information, we developed a method to estimate periurban aboveground biomass (AGB—a proxy for multiple ecosystem services—of secondary Andean forests near Bogotá, Colombia, based on very high resolution (VHR GeoEye-1, Pleiades-1A imagery and field-measured plot data. Specifically, we tested a series of different pre-processing workflows to derive six vegetation indices that were regressed against in situ estimates of AGB. Overall, the coupling of linear models and the Ratio Vegetation Index produced the most satisfactory results. Atmospheric and topographic correction proved to be key in improving model fit, especially in high aerosol and rugged terrain such as the Andes. Methods and findings provide baseline AGB and carbon stock information for little studied periurban Andean secondary forests. The methodological approach can also be used for integrating limited forest monitoring plot AGB data with very high resolution imagery for cost-effective modelling of ecosystem service provision from forests, monitoring reforestation and forest cover change, and for carbon offset assessments.

  20. Top-down Estimates of Biomass Burning Emissions of Black Carbon in the Western United States

    Science.gov (United States)

    Mao, Y.; Li, Q.; Randerson, J. T.; CHEN, D.; Zhang, L.; Liou, K.

    2012-12-01

    We apply a Bayesian linear inversion to derive top-down estimates of biomass burning emissions of black carbon (BC) in the western United States (WUS) for May-November 2006 by inverting surface BC concentrations from the IMPROVE network using the GEOS-Chem chemical transport model. Model simulations are conducted at both 2°×2.5° (globally) and 0.5°×0.667° (nested over North America) horizontal resolutions. We first improve the spatial distributions and seasonal and interannual variations of the BC emissions from the Global Fire Emissions Database (GFEDv2) using MODIS 8-day active fire counts from 2005-2007. The GFEDv2 emissions in N. America are adjusted for three zones: boreal N. America, temperate N. America, and Mexico plus Central America. The resulting emissions are then used as a priori for the inversion. The a posteriori emissions are 2-5 times higher than the a priori in California and the Rockies. Model surface BC concentrations using the a posteriori estimate provide better agreement with IMPROVE observations (~50% increase in the Taylor skill score), including improved ability to capture the observed variability especially during June-September. However, model surface BC concentrations are still biased low by ~30%. Comparisons with the Fire Locating and Modeling of Burning Emissions (FLAMBE) are included.

  1. Microbial uptake of radiolabeled substrates: estimates of growth rates from time course measurements

    International Nuclear Information System (INIS)

    Li, W.K.W.

    1984-01-01

    The uptake of [ 3 H]glucose and a mixture of 3 H-labeled amino acids was measured, in time course fashion, in planktonic microbial assemblages of the eastern tropical Pacific Ocean. The average generation times of those portions of the assemblages able to utilize these substrates were estimated from a simple exponential growth model. Other workers have independently used this model in its integrated or differential form. A mathematical verification and an experimental demonstration of the equivalence of the two approaches are presented. A study was made of the size distribution of heterotrophic activity, using time course measurements. It was found that the size distribution and the effect of sample filtration before radiolabeling were dependent on time of incubation. In principle, it was possible to ascribe these time dependences to differences in th specific growth rate and initial standing stock of the microbial assemblages. 33 references

  2. Structural stability, microbial biomass and community composition of sediments affected by the hydric dynamics of an urban stormwater infiltration basin. Dynamics of physical and microbial characteristics of stormwater sediment.

    Science.gov (United States)

    Badin, Anne Laure; Monier, Armelle; Volatier, Laurence; Geremia, Roberto A; Delolme, Cécile; Bedell, Jean-Philippe

    2011-05-01

    The sedimentary layer deposited at the surface of stormwater infiltration basins is highly organic and multicontaminated. It undergoes considerable moisture content fluctuations due to the drying and inundation cycles (called hydric dynamics) of these basins. Little is known about the microflora of the sediments and its dynamics; hence, the purpose of this study is to describe the physicochemical and biological characteristics of the sediments at different hydric statuses of the infiltration basin. Sediments were sampled at five time points following rain events and dry periods. They were characterized by physical (aggregation), chemical (nutrients and heavy metals), and biological (total, bacterial and fungal biomasses, and genotypic fingerprints of total bacterial and fungal communities) parameters. Data were processed using statistical analyses which indicated that heavy metal (1,841 μg/g dry weight (DW)) and organic matter (11%) remained stable through time. By contrast, aggregation, nutrient content (NH₄⁺, 53-717 μg/g DW), pH (6.9-7.4), and biological parameters were shown to vary with sediment water content and sediment biomass, and were higher consecutive to stormwater flows into the basin (up to 7 mg C/g DW) than during dry periods (0.6 mg C/g DW). Coinertia analysis revealed that the structure of the bacterial communities is driven by the hydric dynamics of the infiltration basin, although no such trend was found for fungal communities. Hydric dynamics more than rain events appear to be more relevant for explaining variations of aggregation, microbial biomass, and shift in the microbial community composition. We concluded that the hydric dynamics of stormwater infiltration basins greatly affects the structural stability of the sedimentary layer, the biomass of the microbial community living in it and its dynamics. The decrease in aggregation consecutive to rewetting probably enhances access to organic matter (OM), explaining the consecutive release

  3. Thalassic biogas production from sea wrack biomass using different microbial seeds: cow manure, marine sediment and sea wrack-associated microflora.

    Science.gov (United States)

    Marquez, Gian Powell B; Reichardt, Wolfgang T; Azanza, Rhodora V; Klocke, Michael; Montaño, Marco Nemesio E

    2013-04-01

    Sea wrack (dislodged sea grasses and seaweeds) was used in biogas production. Fresh water scarcity in island communities where sea wrack could accumulate led to seawater utilization as liquid substrate. Three microbial seeds cow manure (CM), marine sediment (MS), and sea wrack-associated microflora (SWA) were explored for biogas production. The average biogas produced were 2172±156 mL (MS), 1223±308 mL (SWA) and 551±126 mL (CM). Though methane potential (396.9 mL(CH4) g(-1) volatile solid) computed from sea wrack proximate values was comparable to other feedstocks, highest methane yield was low (MS=94.33 mL(CH4) g(-1) VS). Among the microbial seeds, MS proved the best microbial source in utilizing sea wrack biomass and seawater. However, salinity (MS=42‰) observed exceeded average seawater salinity (34‰). Hence, methanogenic activity could have been inhibited. This is the first report on sea wrack biomass utilization for thalassic biogas production. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Urban forest biomass estimates: is it important to use allometric relationships developed specifically for urban trees? 

    Science.gov (United States)

    M.R. McHale; I.C. Burke; M.A. Lefsky; P.J. Peper; E.G. McPherson

    2009-01-01

    Many studies have analyzed the benefits, costs, and carbon storage capacity associated with urban trees. These studies have been limited by a lack of research on urban tree biomass, such that estimates of carbon storage in urban systems have relied upon allometric relationships developed in traditional forests. As urbanization increases globally, it is becoming...

  5. Tropical-forest biomass estimation at X-Band from the spaceborne TanDEM-X interferometer

    Science.gov (United States)

    R. Treuhaft; F. Goncalves; J.R. dos Santos; M. Keller; M. Palace; S.N. Madsen; F. Sullivan; P.M.L.A. Graca

    2014-01-01

    This letter reports the sensitivity of X-band interferometric synthetic aperture radar (InSAR) data from the first dual-spacecraft radar interferometer, TanDEM-X, to variations in tropical-forest aboveground biomass (AGB). It also reports the first tropical-forest AGB estimates fromTanDEM-X data. Tropical forests account for...

  6. Lidar-based estimates of aboveground biomass in the continental US and Mexico using ground, airborne, and satellite observations

    Science.gov (United States)

    Ross Nelson; Hank Margolis; Paul Montesano; Guoqing Sun; Bruce Cook; Larry Corp; Hans-Erik Andersen; Ben deJong; Fernando Paz Pellat; Thaddeus Fickel; Jobriath Kauffman; Stephen Prisley

    2017-01-01

    Existing national forest inventory plots, an airborne lidar scanning (ALS) system, and a space profiling lidar system (ICESat-GLAS) are used to generate circa 2005 estimates of total aboveground dry biomass (AGB) in forest strata, by state, in the continental United States (CONUS) and Mexico. The airborne lidar is used to link ground observations of AGB to space lidar...

  7. Estimating grass nutrients and biomass as an indicator of rangeland (forage) quality and quantity using remote sensing in Savanna ecosystems

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2012-10-01

    Full Text Available and grass quantity, respectively. The objective of the study is to estimate and map leaf N and biomass as an indicator of rangeland quality and quantity using vegetation indices derived from one RapidEye image taken at peak productivity. The study...

  8. Forest biomass estimated from MODIS and FIA data in the Lake States: MN, WI and MI, USA

    Science.gov (United States)

    Daolan Zheng; Linda S. Heath; Mark J. Ducey

    2007-01-01

    This study linked the Moderate Resolution Imaging Spectrometer and USDA Forest Service, Forest Inventory and Analysis (FIA) data through empirical models established using high-resolution Landsat Enhanced Thematic Mapper Plus observations to estimate aboveground biomass (AGB) in three Lake States in the north-central USA. While means obtained from larger sample sizes...

  9. Estimation of above ground biomass by using multispectral data for Evergreen Forest in Phu Hin Rong Kla National Park, Thailand

    International Nuclear Information System (INIS)

    Suwanprasit, C.

    2010-01-01

    Tropical forest is the most important and largest source for stocking CO 2 from the atmosphere which might be one of the main sources of carbon emission, global warming and climate change in recent decades. There are two main objectives of this study. The first one is to establish a relationship between above ground biomass and vegetation indices and the other is to evaluate above ground biomass and carbon sequestration for evergreen forest areas in Phu Hin Rong Kla National park, Thailand. Random sampling design based was applied for calculating the above ground biomass at stand level in the selected area by using Brown and Tsutsumi allometric equations. Landsat 7 ETM+ data in February 2009 was used. Support Vector Machine (SVM) was applied for identifying evergreen forest area. Forty-three of vegetation indices and image transformations were used for finding the best correlation with forest stand biomass. Regression analysis was used to investigate the relationship between the biomass volume at stand level and digital data from the satellite image. TM51 which derived from Tsutsumi allometric equation was the highest correlation with stand biomass. Normalized Difference Vegetation Index (NDVI) was not the best correlation in this study. The best biomass estimation model was from TM51 and ND71 (R2 =0.658). The totals of above ground biomass and carbon sequestration were 112,062,010 ton and 56,031,005 ton respectively. The application of this study would be quite useful for understanding the terrestrial carbon dynamics and global climate change. (author)

  10. Thermal efficiency and particulate pollution estimation of four biomass fuels grown on wasteland

    Energy Technology Data Exchange (ETDEWEB)

    Kandpal, J.B.; Madan, M. [Indian Inst. of Tech., New Delhi (India). Centre for Rural Development and Technology

    1996-10-01

    The thermal performance and concentration of suspended particulate matter were studied for 1-hour combustion of four biomass fuels, namely Acacia nilotica, Leucaena leucocepholea, Jatropha curcus, and Morus alba grown in wasteland. Among the four biomass fuels, the highest thermal efficiency was achieved with Acacia nilotica. The suspended particulate matter concentration for 1-hour combustion of four biomass fuels ranged between 850 and 2,360 {micro}g/m{sup 3}.

  11. Improving artificial forest biomass estimates using afforestation age information from time series Landsat stacks.

    Science.gov (United States)

    Liu, Liangyun; Peng, Dailiang; Wang, Zhihui; Hu, Yong

    2014-11-01

    China maintains the largest artificial forest area in the world. Studying the dynamic variation of forest biomass and carbon stock is important to the sustainable use of forest resources and understanding of the artificial forest carbon budget in China. In this study, we investigated the potential of Landsat time series stacks for aboveground biomass (AGB) estimation in Yulin District, a key region of the Three-North Shelter region of China. Firstly, the afforestation age was successfully retrieved from the Landsat time series stacks in the last 40 years (from 1974 to 2013) and shown to be consistent with the surveyed tree ages, with a root-mean-square error (RMSE) value of 4.32 years and a determination coefficient (R (2)) of 0.824. Then, the AGB regression models were successfully developed by integrating vegetation indices and tree age. The simple ratio vegetation index (SR) is the best candidate of the commonly used vegetation indices for estimating forest AGB, and the forest AGB model was significantly improved using the combination of SR and tree age, with R (2) values from 0.50 to 0.727. Finally, the forest AGB images were mapped at eight epochs from 1985 to 2013 using SR and afforestation age. The total forest AGB in seven counties of Yulin District increased by 20.8 G kg, from 5.8 G kg in 1986 to 26.6 G kg in 2013, a total increase of 360 %. For the persistent forest area since 1974, the forest AGB density increased from 15.72 t/ha in 1986 to 44.53 t/ha in 2013, with an annual rate of about 0.98 t/ha. For the artificial forest planted after 1974, the AGB density increased about 1.03 t/ha a year from 1974 to 2013. The results present a noticeable carbon increment for the planted artificial forest in Yulin District over the last four decades.

  12. Estimates of forest biomass carbon storage inLiaoning Province of Northeast China: a review and assessment.

    Science.gov (United States)

    Yu, Dapao; Wang, Xiaoyu; Yin, You; Zhan, Jinyu; Lewis, Bernard J; Tian, Jie; Bao, Ye; Zhou, Wangming; Zhou, Li; Dai, Limin

    2014-01-01

    Accurate estimates of forest carbon storage and changes in storage capacity are critical for scientific assessment of the effects of forest management on the role of forests as carbon sinks. Up to now, several studies reported forest biomass carbon (FBC) in Liaoning Province based on data from China's Continuous Forest Inventory, however, their accuracy were still not known. This study compared estimates of FBC in Liaoning Province derived from different methods. We found substantial variation in estimates of FBC storage for young and middle-age forests. For provincial forests with high proportions in these age classes, the continuous biomass expansion factor method (CBM) by forest type with age class is more accurate and therefore more appropriate for estimating forest biomass. Based on the above approach designed for this study, forests in Liaoning Province were found to be a carbon sink, with carbon stocks increasing from 63.0 TgC in 1980 to 120.9 TgC in 2010, reflecting an annual increase of 1.9 TgC. The average carbon density of forest biomass in the province has increased from 26.2 Mg ha(-1) in 1980 to 31.0 Mg ha(-1) in 2010. While the largest FBC occurred in middle-age forests, the average carbon density decreased in this age class during these three decades. The increase in forest carbon density resulted primarily from the increased area and carbon storage of mature forests. The relatively long age interval in each age class for slow-growing forest types increased the uncertainty of FBC estimates by CBM-forest type with age class, and further studies should devote more attention to the time span of age classes in establishing biomass expansion factors for use in CBM calculations.

  13. Biomass burning losses of carbon estimated from ecosystem modeling and satellite data analysis for the Brazilian Amazon region

    Science.gov (United States)

    Potter, Christopher; Brooks Genovese, Vanessa; Klooster, Steven; Bobo, Matthew; Torregrosa, Alicia

    To produce a new daily record of gross carbon emissions from biomass burning events and post-burning decomposition fluxes in the states of the Brazilian Legal Amazon (Instituto Brasileiro de Geografia e Estatistica (IBGE), 1991. Anuario Estatistico do Brasil, Vol. 51. Rio de Janeiro, Brazil pp. 1-1024). We have used vegetation greenness estimates from satellite images as inputs to a terrestrial ecosystem production model. This carbon allocation model generates new estimates of regional aboveground vegetation biomass at 8-km resolution. The modeled biomass product is then combined for the first time with fire pixel counts from the advanced very high-resolution radiometer (AVHRR) to overlay regional burning activities in the Amazon. Results from our analysis indicate that carbon emission estimates from annual region-wide sources of deforestation and biomass burning in the early 1990s are apparently three to five times higher than reported in previous studies for the Brazilian Legal Amazon (Houghton et al., 2000. Nature 403, 301-304; Fearnside, 1997. Climatic Change 35, 321-360), i.e., studies which implied that the Legal Amazon region tends toward a net-zero annual source of terrestrial carbon. In contrast, our analysis implies that the total source fluxes over the entire Legal Amazon region range from 0.2 to 1.2 Pg C yr -1, depending strongly on annual rainfall patterns. The reasons for our higher burning emission estimates are (1) use of combustion fractions typically measured during Amazon forest burning events for computing carbon losses, (2) more detailed geographic distribution of vegetation biomass and daily fire activity for the region, and (3) inclusion of fire effects in extensive areas of the Legal Amazon covered by open woodland, secondary forests, savanna, and pasture vegetation. The total area of rainforest estimated annually to be deforested did not differ substantially among the previous analyses cited and our own.

  14. Numbers, biomass and cultivable diversity of microbial populations relate to depth and borehole-specific conditions in groundwater from depths of 4-450 m in Olkiluoto, Finland.

    Science.gov (United States)

    Pedersen, Karsten; Arlinger, Johanna; Eriksson, Sara; Hallbeck, Anna; Hallbeck, Lotta; Johansson, Jessica

    2008-07-01

    Microbiology, chemistry and dissolved gas in groundwater from Olkiluoto, Finland, were analysed over 3 years; samples came from 16 shallow observation tubes and boreholes from depths of 3.9-16.2 m and 14 deep boreholes from depths of 35-742 m. The average total number of cells (TNC) was 3.9 x 10(5) cells per ml in the shallow groundwater and 5.7 x 10(4) cells per ml in the deep groundwater. There was a significant correlation between the amount of biomass, analysed as ATP concentration, and TNC. ATP concentration also correlated with the stacked output of anaerobic most probable number cultivations of nitrate-, iron-, manganese- and sulphate-reducing bacteria, and acetogenic bacteria and methanogens. The numbers and biomass varied at most by approximately three orders of magnitude between boreholes, and TNC and ATP were positively related to the concentration of dissolved organic carbon. Two depth zones were found where the numbers, biomass and diversity of the microbial populations peaked. Shallow groundwater down to a depth of 16.2 m on average contained more biomass and cultivable microorganisms than did deep groundwater, except in a zone at a depth of approximately 300 m where the average biomass and number of cultivable microorganisms approached those of shallow groundwater. Starting at a depth of approximately 300 m, there were steep gradients of decreasing sulphate and increasing methane concentrations with depth; together with the peaks in biomass and sulphide concentration at this depth, these suggest that anaerobic methane oxidation may be a significant process at depth in Olkiluoto.

  15. Biomassa microbiana em amostras de solos secadas ao ar e reumedecidas Microbial biomass in air dried and rewetted soil samples

    Directory of Open Access Journals (Sweden)

    Antônio Samarão Gonçalves

    2002-05-01

    Full Text Available O objetivo do trabalho foi avaliar a viabilidade do condicionamento de amostras como terra fina secada ao ar (TFSA por curto período, para a determinação do carbono da biomassa microbiana (BMS-C, pelo método da fumigaçãoextração, e verificar a respiração microbiana basal (RB do solo. O condicionamento como TFSA, procedendo-se à fumigação para a análise da BMS-C imediatamente ou 24 horas após o reumedecimento, proporcionou valores de BMS-C para os solos Podzólicos, Latossolo Vermelho-Amarelo álico e Orgânico, semelhantes aos valores dos seus controles. Os solos Glei Pouco Húmico e Vertissolo apresentaram valores de BMS-C similares aos do controle a partir de 24 horas de incubação; o solo Planossolo arenoso apresentou valores similares aos do controle com 72 horas, e a Rendizina, com 168 horas de incubação. Na maioria dos solos, a RB determinada na TFSA apresentou valores maiores do que os do tratamento-controle, quando avaliada imediatamente ou 24 horas após o reumedecimento a 60% da capacidade máxima de retenção de água, seguida de queda e manutenção em níveis semelhantes ao do controle nos períodos subseqüentes. O précondicionamento, de curta duração, como TFSA, é promissor para a determinação da BMS-C, quando níveis e períodos adequados de reumedecimento são adotados.The objective of this work was to evaluate the utilization of short term air dried soil samples in a determination of soil microbial biomass (SMB-C, by a fumigationextraction method, and soil microbial basal respiration (BR. Zero time or 24 hours rewetting incubation period before fumigation procedure gave values of SMB-C similar to those of the control for the Podzolic soils, Allic RedYellow Latosol and Organic soil. Low Humic Gley and Vertisol soils gave values of SMB-C similar to those of the control for periods of incubation equal or higher than 24 hours. Planosol (sandy soil and Rendzina soils gave values of SMB-C similar to the

  16. Estimation of methane and nitrous oxide emissions from biomass waste in China:A case study in Hebei Province

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Crop residue,animal manure and MSW are selected as representative biomass waste.Greenhouse gas emissions from treatment and disposal process of biomass waste in Hebei province are estimated for the period from 2002 to 2007,using the methodologies recommended by the Intergovernmental Panel on Climate Change.Greenhouse gas emission was about 10 Mt CO2-equivalent annually.About 6% of greenhouse gas emission came from open burning of crop residue,74% from management system of animal manure,and 20% from MSW disposal.Among all the greenhouse gas sources,landfill is the most concentrated one,and has significant potential of emission reduction.

  17. Using Landsat TM and NFI data to estimate wood volume, tree biomass and stand age in Dalarna

    Energy Technology Data Exchange (ETDEWEB)

    Reese, Heather; Nilsson, Mats

    1999-10-01

    As part of the `Monitoring of forest ecosystems` project, within the MISTRA program Remote Sensing for the Environment (RESE), and also with funding from the County Administration Board of Dalarna, a demonstration project was undertaken to estimate forest stand parameters in Dalarna with the use of satellite data. Using two full scenes of Landsat Thematic Mapper data and sample plot data from the Swedish National Forest Inventory, estimations of above ground tree biomass, age, total wood volume, and separate tree species volumes were made using the `k Nearest Neighbor` method. Accuracy assessment results at the single pixel level for total wood volume are consistent with results from previous kNN estimations, with an overall relative RMSE of 75% for the western scene, and 58% overall relative RMSE for the eastern scene. Validation data show a bias of the estimate toward the mean value of the estimation data. The pixel level estimates of above ground tree biomass and age had similar validation results to those for total wood volume. Biomass estimates had a 77% relative RMSE for the western scene, and 69% for the eastern scene. Age estimates had a relative RMSE of 60% in the western scene and 57% in the eastern scene. The results may suggest the need to incorporate a geographic limitation on the plots used in the estimation, and to further investigate the co-registration between the satellite and plot data. While pixel lever errors are high, an aggregation of the estimates to larger (compartment-sized) areas could decrease the error significantly. Previous similar studies have shown that an RMSE of 10% for total wood volume can be obtained for as small areas as 100 to 450 hectares. The estimates from this study will be evaluated for use by the County Administration Board of Dalarna to find areas of ecological interest and to assist in planning 14 refs, 4 figs, 4 tabs

  18. Improving estimation of tree carbon stocks by harvesting aboveground woody biomass within airborne LiDAR flight areas

    Science.gov (United States)

    Colgan, M.; Asner, G. P.; Swemmer, A. M.

    2011-12-01

    The accurate estimation of carbon stored in a tree is essential to accounting for the carbon emissions due to deforestation and degradation. Airborne LiDAR (Light Detection and Ranging) has been successful in estimating aboveground carbon density (ACD) by correlating airborne metrics, such as canopy height, to field-estimated biomass. This latter step is reliant on field allometry which is applied to forest inventory quantities, such as stem diameter and height, to predict the biomass of a given tree stem. Constructing such allometry is expensive, time consuming, and requires destructive sampling. Consequently, the sample sizes used to construct such allometry are often small, and the largest tree sampled is often much smaller than the largest in the forest population. The uncertainty resulting from these sampling errors can lead to severe biases when the allometry is applied to stems larger than those harvested to construct the allometry, which is then subsequently propagated to airborne ACD estimates. The Kruger National Park (KNP) mission of maintaining biodiversity coincides with preserving ecosystem carbon stocks. However, one hurdle to accurately quantifying carbon density in savannas is that small stems are typically harvested to construct woody biomass allometry, yet they are not representative of Kruger's distribution of biomass. Consequently, these equations inadequately capture large tree variation in sapwood/hardwood composition, root/shoot/leaf allocation, branch fall, and stem rot. This study eliminates the "middleman" of field allometry by directly measuring, or harvesting, tree biomass within the extent of airborne LiDAR. This enables comparisons of field and airborne ACD estimates, and also enables creation of new airborne algorithms to estimate biomass at the scale of individual trees. A field campaign was conducted at Pompey Silica Mine 5km outside Kruger National Park, South Africa, in Mar-Aug 2010 to harvest and weigh tree mass. Since

  19. [Tree above-ground biomass allometries for carbon stocks estimation in the Caribbean mangroves in Colombia].

    Science.gov (United States)

    Yepes, Adriana; Zapata, Mauricio; Bolivar, Jhoanata; Monsalve, Alejandra; Espinosa, Sandra Milena; Sierra-Correa, Paula Cristina; Sierra, Andrés

    2016-06-01

    The distribution of carbon in “Blue Carbon” ecosystems such as mangroves is little known, when compared with the highly known terrestrial forests, despite its particular and recognized high productivity and carbon storage capacity. The objective of this study was to analyze the above ground biomass (AGB) of the species Rhizophora mangle and Avicennia germinans from the Marine Protected Area of Distrito de Manejo Integrado (DMI), Cispatá-Tinajones-La Balsa, Caribbean Colombian coast. With official authorization, we harvested and studied 30 individuals of each species, and built allometric models in order to estimate AGB. Our AGB results indicated that the studied mangrove forests of the DMI Colombian Caribbean was of 129.69 ± 20.24 Mg/ha, equivalent to 64.85 ± 10.12 MgC/ha. The DMI has an area of 8 570.9 ha in mangrove forests, and we estimated that the total carbon potential stored was about 555 795.93 Mg C. The equations generated in this study can be considered as an alternative for the assessment of carbon stocks in AGB of mangrove forests in Colombia; as other available AGB allometric models do not discriminate mangrove forests, despite being particular ecosystems. They can be used for analysis at a more detailed scale and are considered useful to determine the carbon storage potential of mangrove forests, as a country alternative to support forest conservation and emission reduction strategies. In general, the potential of carbon storage from Colombian Caribbean mangrove forests is important and could promote the country leadership of the “blue carbon” stored.

  20. Sustainability of biomass electricity systems. An estimate of costs, macro-economic and environmental impacts

    International Nuclear Information System (INIS)

    Van den Broek, R

    2001-01-01

    Since the 1990s there has been a renewal of interest in the possibility of sustainable generating energy from biomass, an interest driven in part by the climate issue. Other motives are the search for alternatives for parts of Western agriculture and progress in the technological feasibility of efficiently producing high-quality energy from biomass. World-wide this renewed interest has led to a clear increase in research, demonstration and commercial implementation of biomass energy systems. A recent thesis concludes that biomass can contribute to all aspects of sustainability. In the context of sustainable development (often viewed as a concept having economic, social and ecological dimensions), the central question asked by this Ph.D. research is: How do biomass electricity systems compare to fossil-fuel systems and to the land-use that they may replace, in terms of costs, macro-economic and environmental impacts. This article presents a number of conclusions

  1. [Models for biomass estimation of four shrub species planted in urban area of Xi'an city, Northwest China].

    Science.gov (United States)

    Yao, Zheng-Yang; Liu, Jian-Jun

    2014-01-01

    Four common greening shrub species (i. e. Ligustrum quihoui, Buxus bodinieri, Berberis xinganensis and Buxus megistophylla) in Xi'an City were selected to develop the highest correlation and best-fit estimation models for the organ (branch, leaf and root) and total biomass against different independent variables. The results indicated that the organ and total biomass optimal models of the four shrubs were power functional model (CAR model) except for the leaf biomass model of B. megistophylla which was logarithmic functional model (VAR model). The independent variables included basal diameter, crown diameter, crown diameter multiplied by height, canopy area and canopy volume. B. megistophylla significantly differed from the other three shrub species in the independent variable selection, which were basal diameter and crown-related factors, respectively.

  2. Mild-temperature thermochemical pretreatment of green macroalgal biomass: Effects on solubilization, methanation, and microbial community structure.

    Science.gov (United States)

    Jung, Heejung; Baek, Gahyun; Kim, Jaai; Shin, Seung Gu; Lee, Changsoo

    2016-01-01

    The effects of mild-temperature thermochemical pretreatments with HCl or NaOH on the solubilization and biomethanation of Ulva biomass were assessed. Within the explored region (0-0.2M HCl/NaOH, 60-90°C), both methods were effective for solubilization (about 2-fold increase in the proportion of soluble organics), particularly under high-temperature and high-chemical-dose conditions. However, increased solubilization was not translated into enhanced biogas production for both methods. Response surface analysis statistically revealed that HCl or NaOH addition enhances the solubilization degree while adversely affects the methanation. The thermal-only treatment at the upper-limit temperature (90°C) was estimated to maximize the biogas production for both methods, suggesting limited potential of HCl/NaOH treatment for enhanced Ulva biomethanation. Compared to HCl, NaOH had much stronger positive and negative effects on the solubilization and methanation, respectively. Methanosaeta was likely the dominant methanogen group in all trials. Bacterial community structure varied among the trials according primarily to HCl/NaOH addition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Scenario uncertainties in estimating direct land-use change emissions in biomass-to-energy life cycle assessment

    International Nuclear Information System (INIS)

    Curtright, Aimee E.; Johnson, David R.; Willis, Henry H.; Skone, Timothy

    2012-01-01

    The use of biomass for energy production has increasingly been encouraged in the United States, in part motivated by the potential to reduce greenhouse gas (GHG) emissions relative to fossil fuels. However, the GHG-intensity of biomass-derived energy is highly dependent on how the biomass is obtained and used. We explore scenario uncertainty in GHG estimates in the Calculating Uncertainty in Biomass Emissions (CUBE) model and find that direct land-use change emissions that result during the biomass production often dominate the total “farm-to-hopper” GHGs. CUBE represents each land-use change decision as a conversion of land from one of four specified baseline ecosystem to produce one of seven feedstock crops, both distinct by geographic region, and then determines the implied changes in soil organic carbon, root carbon, and above-ground biomass. CUBE therefore synthesizes and organizes the existing literature to represent direct land-use change emissions in a way that can be more readily incorporated into life cycle assessment. Our approach to representing direct land-use change literature has been applied to a specific set of data and offers immediate implications for decisionmakers, but it can also be generalized and replicated in the future, making use of improved scientific data on the magnitude and rates of direct land-use change emissions as it becomes available. -- Highlights: ► The GHG-intensity of bioenergy depends on how the biomass is obtained and used. ► Total GHG emissions may be dominated by direct land-use change emissions. ► There is significant scenario uncertainty in emissions based on the location of production. ► Emissions vary based on time elapsed since land-use change conversions. ► Our approach can be generalized to use improved scientific data in the future.

  4. Estimating Hydrogen Production Potential in Biorefineries Using Microbial Electrolysis Cell Technology

    Energy Technology Data Exchange (ETDEWEB)

    Borole, Abhijeet P [ORNL; Mielenz, Jonathan R [ORNL

    2011-01-01

    Microbial electrolysis cells (MECs) are devices that use a hybrid biocatalysis-electrolysis process for production of hydrogen from organic matter. Future biofuel and bioproducts industries are expected to generate significant volumes of waste streams containing easily degradable organic matter. The emerging MEC technology has potential to derive added- value from these waste streams via production of hydrogen. Biorefinery process streams, particularly the stillage or distillation bottoms contain underutilized sugars as well as fermentation and pretreatment byproducts. In a lignocellulosic biorefinery designed for producing 70 million gallons of ethanol per year, up to 7200 m3/hr of hydrogen can be generated. The hydrogen can either be used as an energy source or a chemical reagent for upgrading and other reactions. The energy content of the hydrogen generated is sufficient to meet 57% of the distillation energy needs. We also report on the potential for hydrogen production in existing corn mills and sugar-based biorefineries. Removal of the organics from stillage has potential to facilitate water recycle. Pretreatment and fermentation byproducts generated in lignocellulosic biorefinery processes can accumulate to highly inhibitory levels in the process streams, if water is recycled. The byproducts of concern including sugar- and lignin- degradation products such as furans and phenolics can also be converted to hydrogen in MECs. We evaluate hydrogen production from various inhibitory byproducts generated during pretreatment of various types of biomass. Finally, the research needs for development of the MEC technology and aspects particularly relevant to the biorefineries are discussed.

  5. Estimation of lichen biomass with emphasis on reindeer winter pastures at Hardangervidda, S Norway

    OpenAIRE

    Arvid Odland; Sylvi M. Sandvik; Dag K. Bjerketvedt; Linn L. Myrvold

    2014-01-01

    Quantification of lichen abundance is important for management of reindeer populations. We measured dry lichen biomass in 876 micro plots (16.5 cm × 16.5 cm) systematically sampled within 219 vegetation plots (2 m × 2 m) from 7 different areas in S Norway. Lichen biomass was quantified as: (a) dry weight in g m-2, (b) lichen height in cm, (c) lichen cover, and (d) lichen volume (lichen height × lichen cover). Lichen biomass decreased with increasing precipitation and increasing altitude. On l...

  6. Seasonal and diel effects on acoustic fish biomass estimates: application to a shallow reservoir with untargeted common carp (Cyprinus carpio)

    Science.gov (United States)

    Djemali, Imed; Yule, Daniel; Guillard, Jean

    2016-01-01

    The aim of the present study was to understand how seasonal fish distributions affect acoustically derived fish biomass estimates in a shallow reservoir in a semi-arid country (Tunisia). To that end, sampling events were performed during four seasons (spring (June), summer (September), autumn (December) and winter (March)) that included day and night surveys. A Simrad EK60 echosounder, equipped with two 120-kHz split-beam transducers for simultaneous horizontal and vertical beaming, was used to sample the entire water column. Surveys during spring and summer and daytime hours of winter were deemed unusable owing to high methane flux from the sediment, and during the day survey of autumn, fish were close to the reservoir bottom leading to low detectability. It follows that acoustic surveys should be conducted only at night during the cold season (December–March) for shallow reservoirs having carp Cyprinus carpio (L.) as the dominant species. Further, night-time biomass estimates during the cold season declined significantly (P < 0.001) from autumn to winter. Based on our autumn night-time survey, overall fish biomass in the Bir-Mcherga Reservoir was high (mean (± s.d.) 185 ± 98 tonnes (Mg)), but annual fishery exploitation is low (19.3–24.1 Mg) because the fish biomass is likely dominated by invasive carp not targeted by fishers. The results suggest that controlling carp would help improve the fishery.

  7. Estimates of global biomass burning emissions for reactive greenhouse gases (CO, NMHCs, and NOx) and CO2

    Science.gov (United States)

    Jain, Atul K.; Tao, Zhining; Yang, Xiaojuan; Gillespie, Conor

    2006-03-01

    Open fire biomass burning and domestic biofuel burning (e.g., cooking, heating, and charcoal making) algorithms have been incorporated into a terrestrial ecosystem model to estimate CO2 and key reactive GHGs (CO, NOx, and NMHCs) emissions for the year 2000. The emissions are calculated over the globe at a 0.5° × 0.5° spatial resolution using tree density imagery, and two separate sets of data each for global area burned and land clearing for croplands, along with biofuel consumption rate data. The estimated global and annual total dry matter (DM) burned due to open fire biomass burning ranges between 5221 and 7346 Tg DM/yr, whereas the resultant emissions ranges are 6564-9093 Tg CO2/yr, 438-568 Tg CO/yr, 11-16 Tg NOx/yr (as NO), and 29-40 Tg NMHCs/yr. The results indicate that land use changes for cropland is one of the major sources of biomass burning, which amounts to 25-27% (CO2), 25 -28% (CO), 20-23% (NO), and 28-30% (NMHCs) of the total open fire biomass burning emissions of these gases. Estimated DM burned associated with domestic biofuel burning is 3,114 Tg DM/yr, and resultant emissions are 4825 Tg CO2/yr, 243 Tg CO/yr, 3 Tg NOx/yr, and 23 Tg NMHCs/yr. Total emissions from biomass burning are highest in tropical regions (Asia, America, and Africa), where we identify important contributions from primary forest cutting for croplands and domestic biofuel burning.

  8. Acoustic Estimates of Distribution and Biomass of Different Acoustic Scattering Types Between the New England Shelf Break and Slope Waters

    KAUST Repository

    McLaren, Alexander

    2011-11-01

    Due to their great ecological significance, mesopelagic fishes are attracting a wider audience on account of the large biomass they represent. Data from the National Marine Fisheries Service (NMFS) provided the opportunity to explore an unknown region of the North-West Atlantic, adjacent to one of the most productive fisheries in the world. Acoustic data collected during the cruise required the identification of acoustically distinct scattering types to make inferences on the migrations, distributions and biomass of mesopelagic scattering layers. Six scattering types were identified by the proposed method in our data and traces their migrations and distributions in the top 200m of the water column. This method was able to detect and trace the movements of three scattering types to 1000m depth, two of which can be further subdivided. This process of identification enabled the development of three physically-derived target-strength models adapted to traceable acoustic scattering types for the analysis of biomass and length distribution to 1000m depth. The abundance and distribution of acoustic targets varied closely in relation to varying physical environments associated with a warm core ring in the New England continental Shelf break region. The continental shelf break produces biomass density estimates that are twice as high as the warm core ring and the surrounding continental slope waters are an order of magnitude lower than either estimate. Biomass associated with distinct layers is assessed and any benefits brought about by upwelling at the edge of the warm core ring are shown not to result in higher abundance of deepwater species. Finally, asymmetric diurnal migrations in shelf break waters contrasts markedly with the symmetry of migrating layers within the warm ring, both in structure and density estimates, supporting a theory of predatorial and nutritional constraints to migrating pelagic species.

  9. Achieving Accuracy Requirements for Forest Biomass Mapping: A Data Fusion Method for Estimating Forest Biomass and LiDAR Sampling Error with Spaceborne Data

    Science.gov (United States)

    Montesano, P. M.; Cook, B. D.; Sun, G.; Simard, M.; Zhang, Z.; Nelson, R. F.; Ranson, K. J.; Lutchke, S.; Blair, J. B.

    2012-01-01

    The synergistic use of active and passive remote sensing (i.e., data fusion) demonstrates the ability of spaceborne light detection and ranging (LiDAR), synthetic aperture radar (SAR) and multispectral imagery for achieving the accuracy requirements of a global forest biomass mapping mission. This data fusion approach also provides a means to extend 3D information from discrete spaceborne LiDAR measurements of forest structure across scales much larger than that of the LiDAR footprint. For estimating biomass, these measurements mix a number of errors including those associated with LiDAR footprint sampling over regional - global extents. A general framework for mapping above ground live forest biomass (AGB) with a data fusion approach is presented and verified using data from NASA field campaigns near Howland, ME, USA, to assess AGB and LiDAR sampling errors across a regionally representative landscape. We combined SAR and Landsat-derived optical (passive optical) image data to identify forest patches, and used image and simulated spaceborne LiDAR data to compute AGB and estimate LiDAR sampling error for forest patches and 100m, 250m, 500m, and 1km grid cells. Forest patches were delineated with Landsat-derived data and airborne SAR imagery, and simulated spaceborne LiDAR (SSL) data were derived from orbit and cloud cover simulations and airborne data from NASA's Laser Vegetation Imaging Sensor (L VIS). At both the patch and grid scales, we evaluated differences in AGB estimation and sampling error from the combined use of LiDAR with both SAR and passive optical and with either SAR or passive optical alone. This data fusion approach demonstrates that incorporating forest patches into the AGB mapping framework can provide sub-grid forest information for coarser grid-level AGB reporting, and that combining simulated spaceborne LiDAR with SAR and passive optical data are most useful for estimating AGB when measurements from LiDAR are limited because they minimized

  10. 3D Ground Penetrating Radar to Detect Tree Roots and Estimate Root Biomass in the Field

    Directory of Open Access Journals (Sweden)

    Shiping Zhu

    2014-06-01

    Full Text Available The objectives of this study were to detect coarse tree root and to estimate root biomass in the field by using an advanced 3D Ground Penetrating Radar (3D GPR system. This study obtained full-resolution 3D imaging results of tree root system using 500 MHz and 800 MHz bow-tie antennas, respectively. The measurement site included two larch trees, and one of them was excavated after GPR measurements. In this paper, a searching algorithm, based on the continuity of pixel intensity along the root in 3D space, is proposed, and two coarse roots whose diameters are more than 5 cm were detected and delineated correctly. Based on the detection results and the measured root biomass, a linear regression model is proposed to estimate the total root biomass in different depth ranges, and the total error was less than 10%. Additionally, based on the detected root samples, a new index named “magnitude width” is proposed to estimate the root diameter that has good correlation with root diameter compared with other common GPR indexes. This index also provides direct measurement of the root diameter with 13%–16% error, providing reasonable and practical root diameter estimation especially in the field.

  11. Responses of soil microbial biomass and bacterial community structure to closed-off management (an ecological natural restoration measures): A case study of Dongting Lake wetland, middle China.

    Science.gov (United States)

    Dai, Juan; Wu, Haipeng; Zhang, Chang; Zeng, Guangming; Liang, Jie; Guo, Shenglian; Li, Xiaodong; Huang, Lu; Lu, Lunhui; Yuan, Yujie

    2016-09-01

    Soil microbial biomass (SMB) and bacterial community structure, which are critical to global ecosystem and fundamental ecological processes, are sensitive to anthropogenic activities and environmental conditions. In this study, we examined the possible effects of closed-off management (an ecological natural restoration measures, ban on anthropogenic activity, widely employed for many important wetlands) on SMB, soil bacterial community structure and functional marker genes of nitrogen cycling in Dongting Lake wetland. Soil samples were collected from management area (MA) and contrast area (CA: human activities, such as hunting, fishing and draining, are permitted) in November 2013 and April 2014. Soil properties, microbial biomass carbon (MBC), and bacterial community structure were investigated. Comparison of the values of MA and CA showed that SMB and bacterial community diversity of the MA had a significant increase after 7 years closed-off management. The mean value of Shannon-Weiner diversity index of MA and CA respectively were 2.85 and 2.07. The gene copy numbers of 16S rRNA and nosZ of MA were significant higher than those of CA. the gene copy numbers of ammonia-oxidizing archaea (AOA) and nirK of MA were significant lower than those of CA. However, there was no significant change in the gene copy numbers of ammonia-oxidizing bacteria (AOB) and nirS. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  12. Cultivation of high-biomass crops on coal mine spoil banks: Can microbial inoculation compensate for high doses of organic matter?

    Energy Technology Data Exchange (ETDEWEB)

    Gryndler, M.; Sudova, R.; Puschel, D.; Rydlova, J.; Janouskova, M.; Vosatka, M. [Academy of Science Czech Republic, Pruhonice (Czech Republic)

    2008-09-15

    Two greenhouse experiments were focused on the application of arbuscular mycorrhizal fungi (AMF) and plant growth promoting rhizobacteria (PGPR) in planting of high-biomass crops on reclaimed spoil banks. In the first experiment, we tested the effects of different organic amendments on growth of alfalfa and on the introduced microorganisms. While growth of plants was supported in substrate with compost amendment, mycorrhizal colonization was suppressed. Lignocellulose papermill waste had no negative effects on AMF, but did not positively affect growth of plants. The mixture of these two amendments was found to be optimal in both respects, plant growth and mycorrhizal development. Decreasing doses of this mixture amendment were used in the second experiment, where the effects of microbial inoculation (assumed to compensate for reduced doses of organic matter) on growth of two high-biomass crops, hemp and reed canarygrass, were studied. Plant growth response to microbial inoculation was either positive or negative, depending on the dose of the applied amendment and plant species.

  13. Optically-derived estimates of phytoplankton size class and taxonomic group biomass in the Eastern Subarctic Pacific Ocean

    Science.gov (United States)

    Zeng, Chen; Rosengard, Sarah Z.; Burt, William; Peña, M. Angelica; Nemcek, Nina; Zeng, Tao; Arrigo, Kevin R.; Tortell, Philippe D.

    2018-06-01

    We evaluate several algorithms for the estimation of phytoplankton size class (PSC) and functional type (PFT) biomass from ship-based optical measurements in the Subarctic Northeast Pacific Ocean. Using underway measurements of particulate absorption and backscatter in surface waters, we derived estimates of PSC/PFT based on chlorophyll-a concentrations (Chl-a), particulate absorption spectra and the wavelength dependence of particulate backscatter. Optically-derived [Chl-a] and phytoplankton absorption measurements were validated against discrete calibration samples, while the derived PSC/PFT estimates were validated using size-fractionated Chl-a measurements and HPLC analysis of diagnostic photosynthetic pigments (DPA). Our results showflo that PSC/PFT algorithms based on [Chl-a] and particulate absorption spectra performed significantly better than the backscatter slope approach. These two more successful algorithms yielded estimates of phytoplankton size classes that agreed well with HPLC-derived DPA estimates (RMSE = 12.9%, and 16.6%, respectively) across a range of hydrographic and productivity regimes. Moreover, the [Chl-a] algorithm produced PSC estimates that agreed well with size-fractionated [Chl-a] measurements, and estimates of the biomass of specific phytoplankton groups that were consistent with values derived from HPLC. Based on these results, we suggest that simple [Chl-a] measurements should be more fully exploited to improve the classification of phytoplankton assemblages in the Northeast Pacific Ocean.

  14. Impact of land-use and long-term (>150 years) charcoal accumulation on microbial activity, biomass and community structure in temperate soils (Belgium).

    Science.gov (United States)

    Hardy, Brieuc; Cornelis, Jean-Thomas; Dufey, Joseph E.

    2015-04-01

    In the last decade, biochar has been increasingly investigated as a soil amendment for long-term soil carbon sequestration while improving soil fertility. On the short term, biochar application to soil generally increases soil respiration as well as microbial biomass and activity and affects significantly the microbial community structure. However, such effects are relatively short-term and tend to vanish over time. In our study, we investigated the long-term impact of charcoal accumulation and land-use on soil biota in temperate haplic Luvisols developed in the loess belt of Wallonia (Belgium). Charcoal-enriched soils were collected in the topsoil of pre-industrial (>150 years old) charcoal kilns in forest (4 sites) and cropland (5 sites). The topsoil of the adjacent charcoal-unaffected soils was sampled in a comparable way. Soils were characterized (pH, total, organic and inorganic C, total N, exchangeable Ca, Mg, K, Na, cation exchange capacity and available P) and natural soil organic matter (SOM) and black carbon (BC) contents were determined by differential scanning calorimetry. After rewetting at pF 2.5, soils were incubated during 140 days at 20 °C. At 70 days of incubation, 10 g of each soil were freeze dried in order to measure total microbial biomass and community structure by PLFA analysis. The PLFA dataset was analyzed by principal component analysis (PCA) while soil parameters were used as supplementary variables. For both agricultural and forest soils, the respiration rate is highly related to the total microbial biomass (R²=0.90). Both soil respiration and microbial biomass greatly depend on the SOM content, which indicates that the BC pool is relatively inert microbiologically. Land-use explains most of the variance in the PLFA dataset, largely governing the first principal component of the ACP. In forest soils, we observe a larger proportion of gram + bacteria, actinomycetes and an increased bacteria:fungi ratio compared to cropland, where gram

  15. Hydroacoustic estimation of fish biomass in the Gulf of Nicoya, Costa Rica

    Directory of Open Access Journals (Sweden)

    John Hedgepeth

    2000-06-01

    Full Text Available A stratified sampling design was used for a hydroacoustic survey of the inner parts of the Gulf of Nicoya in 1987 and 1988. The bottom topography of the inner Gulf was modeled by introducing the concept of a topographical basin model, as the basis for the projection of the sample survey estimates to the entire inner gulf. The bottom depth contours and volumes for the basin model were constructed from nautical charts. The estimates of sample abundance were made for the fish in the inner Gulf using the acoustic methods, EMS (Expectation Maximization and Smoothing and echo integration. The estimates of population were made by the multiplication of the topographic model's estimate of water volume and a model of fish density dependent on bottom depth. The results showed a general decrease in fish density biomass with bottom depth, and a simultaneous tendency for maximum concentrations over bottom depths of about four meters. The four meter bottom depth includes a broad expanse of the inner Gulf located south of Isla Chira. Overall estimates of volumetric density (0.269 fish/m³ and of areal densities (1.88 fish/m² are comparable to other estuarine shallow water environments.Se utilizó un diseño muestral estratificado para llevar a cabo una evaluación hidroacústica de la sección interior del Golfo de Nicoya. La topografía submarina fue modelada introduciendo el concepto topográfico de la cuenca, como una forma de proyectar los estimados del muestreo a todo el Golfo interno. Las isobatas y volúmenes de la cuenca del Golfo fueron construidos a partir de cartas náuticas. Los estimados de abundancia en las muestras se hicieron para los peces en la parte interna del Golfo utilizando los métodos acústicos conocidos como EMS (Expectation, Maximitation and Smoothing y ecointegración. Los estimados de población se obtuvieron a partir de la multiplicación de los estimados del modelo topográfico de volúmen acuático y un modelo de densidad de

  16. Generic biomass functions for Norway spruce in Central Europe--a meta-analysis approach toward prediction and uncertainty estimation.

    Science.gov (United States)

    Wirth, Christian; Schumacher, Jens; Schulze, Ernst-Detlef

    2004-02-01

    To facilitate future carbon and nutrient inventories, we used mixed-effect linear models to develop new generic biomass functions for Norway spruce (Picea abies (L.) Karst.) in Central Europe. We present both the functions and their respective variance-covariance matrices and illustrate their application for biomass prediction and uncertainty estimation for Norway spruce trees ranging widely in size, age, competitive status and site. We collected biomass data for 688 trees sampled in 102 stands by 19 authors. The total number of trees in the "base" model data sets containing the predictor variables diameter at breast height (D), height (H), age (A), site index (SI) and site elevation (HSL) varied according to compartment (roots: n = 114, stem: n = 235, dry branches: n = 207, live branches: n = 429 and needles: n = 551). "Core" data sets with about 40% fewer trees could be extracted containing the additional predictor variables crown length and social class. A set of 43 candidate models representing combinations of lnD, lnH, lnA, SI and HSL, including second-order polynomials and interactions, was established. The categorical variable "author" subsuming mainly methodological differences was included as a random effect in a mixed linear model. The Akaike Information Criterion was used for model selection. The best models for stem, root and branch biomass contained only combinations of D, H and A as predictors. More complex models that included site-related variables resulted for needle biomass. Adding crown length as a predictor for needles, branches and roots reduced both the bias and the confidence interval of predictions substantially. Applying the best models to a test data set of 17 stands ranging in age from 16 to 172 years produced realistic allocation patterns at the tree and stand levels. The 95% confidence intervals (% of mean prediction) were highest for crown compartments (approximately +/- 12%) and lowest for stem biomass (approximately +/- 5%), and

  17. Effect of Arbuscular Mycorrhizal Fungi on Plant Biomass and the Rhizosphere Microbial Community Structure of Mesquite Grown in Acidic Lead/Zinc Mine Tailings

    Science.gov (United States)

    Solís-Domínguez, Fernando A.; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M.

    2011-01-01

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by AMF, or a combination of both mechanisms. PMID:21211826

  18. [Effects of simulated nitrogen deposition on soil microbial biomass carbon and nitrogen in natural evergreen broad-leaved forest in the Rainy Area of West China].

    Science.gov (United States)

    Zhou, Shi Xing; Zou, Cheng; Xiao, Yong Xiang; Xiang, Yuan Bin; Han, Bo Han; Tang, Jian Dong; Luo, Chao; Huang, Cong de

    2017-01-01

    To understand the effects of increasing nitrogen deposition on soil microbial biomass carbon (MBC) and nitrogen(MBN), an in situ experiment was conducted in a natural evergreen broad-leaved forest in Ya'an City, Sichuan Province. Four levels of nitrogen deposition were set: i.e., control (CK, 0 g N·m -2 ·a -1 ), low nitrogen (L, 5 g N·m -2 ·a -1 ), medium nitrogen (M, 15 g N·m -2 ·a -1 ), and high nitrogen (H, 30 g N·m -2 ·a -1 ). The results indicated that nitrogen deposition significantly decreased MBC and MBN in the 0-10 cm soil layer, and as N de-position increased, the inhibition effect was enhanced. L and M treatments had no significant effect on MBC and MBN in the 10-20 cm soil layer, while H treatment significantly reduced. The influence of N deposition on MBC and MBN was weakened with the increase of soil depth. MBC and MBN had obvious seasonal dynamic, which were highest in autumn and lowest in summer both in the 0-10 and 10-20 cm soil layers. The fluctuation ranges of soil microbial biomass C/N were respectively 10.58-11.19 and 9.62-12.20 in the 0-10 cm and 10-20 cm soil layers, which indicated that the fungi hold advantage in the soil microbial community in this natural evergreen broad-leaved forest.

  19. Effect of arbuscular mycorrhizal fungi on plant biomass and the rhizosphere microbial community structure of mesquite grown in acidic lead/zinc mine tailings.

    Science.gov (United States)

    Solís-Domínguez, Fernando A; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M

    2011-02-15

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p<0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  20. Descendant root volume varies as a function of root type: estimation of root biomass lost during uprooting in Pinus pinaster

    OpenAIRE

    Danjon, Frédéric; Caplan, Joshua S.; Fortin, Mathieu; Meredieu, Céline

    2013-01-01

    Root systems of woody plants generally display a strong relationship between the cross-sectional area or cross-sectional diameter (CSD) of a root and the dry weight of biomass (DWd) or root volume (Vd) that has grown (i.e., is descendent) from a point. Specification of this relationship allows one to quantify root architectural patterns and estimate the amount of material lost when root systems are extracted from the soil. However, specifications of this relationship generally do not account ...

  1. Enhanced conversion of newly-added maize straw to soil microbial biomass C under plastic film mulching and organic manure management

    Science.gov (United States)

    Jin, X.; Filley, T. R.

    2017-12-01

    Management of crop residues using plastic film mulching (PFM) has the potential to improve soil health by accelerating nutrient cycling and facilitating stable C pool production; however, a key aspect of this process—microbial immobilization of residue C—is poorly understood, especially under PFM when combined with different fertilization treatments. A 360-day in situ 13C-tracing technique was used to analyze the contribution and dynamics of microbial biomass C (MBC) to soil organic C (SOC) after 13C-labelled maize straw residue was applied to micro-plot topsoil in a cultivated maize (Zea mays L.) field under 27-year PFM and four fertilization treatments. Over the course of the experiment, MBC content was significantly (P<0.05) higher in treatments of manure (M) and manure plus nitrogen (MN) compared to the no-fertilization (CK) and nitrogen (N) treatments, regardless of PFM. Compared to no PFM controls, PFM enhanced the decomposition of maize straw during summer (Day 60) in the M and MN treatments, exhibiting increases of 93.0% and 28.6% in straw-derived 13C-MBC and 80.4% and 82.9% in 13C-MBC/13C-SOC, respectively. Overall, both PFM and organic manure treatments improved soil fertility through microbe-mediated incorporation of C derived from newly-added maize straw. Our results indicate that microbial growth and activity are affected by the utilization of different C sources and most dramatically during early seasonal transition.

  2. Soil microbial biomass under pine forests in the north-western Spain: influence of stand age, site index and parent material

    Energy Technology Data Exchange (ETDEWEB)

    Mahia, J.; Perez-Ventura, L.; Cabaneiro, A.; Diaz-Ravina, M.

    2006-07-01

    The effects of stand age, site index and parent material on soil biochemical properties related to biomass (extractable C, microbial C and metabolic quotient) were examined in the 0-15 cm mineral soil layers of Pinus pinaster and Pinus sylvestris stand from NW Spain. Two productivity levels (low and high site index), two ages (young and old) and two parent soil materials (granite and acid schists) were considered. The data indicated that there were differences in microbial parameters in soils under different species. In general in P. pinaster forest higher values of biochemical parameters expressed on organic C basis, were observed in the stands of high site index as compared with the low ones; in contrast, in P. sylvestris no differences among stand site index were detected. In both species different results were also observed depending on parent material and a significant effect of stand age was detected for extractable C and microbial C in P. pinaster forest developed over granite. The data seem to indicate that measured parameters may have the potential to be used as indicators of the effect of forest management on soil organic matter quality. (Author) 25 refs.

  3. [Estimating individual tree aboveground biomass of the mid-subtropical forest using airborne LiDAR technology].

    Science.gov (United States)

    Liu, Feng; Tan, Chang; Lei, Pi-Feng

    2014-11-01

    Taking Wugang forest farm in Xuefeng Mountain as the research object, using the airborne light detection and ranging (LiDAR) data under leaf-on condition and field data of concomitant plots, this paper assessed the ability of using LiDAR technology to estimate aboveground biomass of the mid-subtropical forest. A semi-automated individual tree LiDAR cloud point segmentation was obtained by using condition random fields and optimization methods. Spatial structure, waveform characteristics and topography were calculated as LiDAR metrics from the segmented objects. Then statistical models between aboveground biomass from field data and these LiDAR metrics were built. The individual tree recognition rates were 93%, 86% and 60% for coniferous, broadleaf and mixed forests, respectively. The adjusted coefficients of determination (R(2)adj) and the root mean squared errors (RMSE) for the three types of forest were 0.83, 0.81 and 0.74, and 28.22, 29.79 and 32.31 t · hm(-2), respectively. The estimation capability of model based on canopy geometric volume, tree percentile height, slope and waveform characteristics was much better than that of traditional regression model based on tree height. Therefore, LiDAR metrics from individual tree could facilitate better performance in biomass estimation.

  4. Parameter estimations in predictive microbiology: Statistically sound modelling of the microbial growth rate.

    Science.gov (United States)

    Akkermans, Simen; Logist, Filip; Van Impe, Jan F

    2018-04-01

    When building models to describe the effect of environmental conditions on the microbial growth rate, parameter estimations can be performed either with a one-step method, i.e., directly on the cell density measurements, or in a two-step method, i.e., via the estimated growth rates. The two-step method is often preferred due to its simplicity. The current research demonstrates that the two-step method is, however, only valid if the correct data transformation is applied and a strict experimental protocol is followed for all experiments. Based on a simulation study and a mathematical derivation, it was demonstrated that the logarithm of the growth rate should be used as a variance stabilizing transformation. Moreover, the one-step method leads to a more accurate estimation of the model parameters and a better approximation of the confidence intervals on the estimated parameters. Therefore, the one-step method is preferred and the two-step method should be avoided. Copyright © 2017. Published by Elsevier Ltd.

  5. Energy values and estimation of power generation potentials of some non-woody biomass species

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M; Patel, S K [National Institute of Technology, Rourkela (India)

    2008-07-01

    In view of high energy potentials in non-woody biomass species and an increasing interest in their utilization for power generation, an attempt has been made in this study to assess the proximate analysis and energy content of different components of Ocimum canum and Tridax procumbens biomass species (both non-woody), and their impact on power generation and land requirement for energy plantations. The net energy content in Ocimum canum was found to be slightly higher than that in Tridax procumbens. In spite of having higher ash contents, the barks from both the plant species exhibited higher calorific values. The results have shown that approximately 650 and 1,270 hectares of land are required to generate 20,000 kWh/day electricity from Ocimum canum and Tridax procumbens biomass species. Coal samples, obtained from six different local mines, were also examined for their qualities, and the results were compared with those of studied biomass materials. This comparison reveals much higher power output with negligible emission of suspended particulate matters (SPM) from biomass materials.

  6. Estimation of the fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample

    DEFF Research Database (Denmark)

    Waul, Christopher Kevin; Arvin, Erik; Schmidt, Jens Ejbye

    2008-01-01

    The fraction of biologically active methyl tert-butyl ether degraders in reactors is just as important for prediction of removal rates as knowledge of the kinetic parameters. The fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample, taken from a packed...... bed reactor, was determined using a batch kinetic based approach. The procedure involved modeling of methyl tert-butyl ether removal rates from batch experiments followed by parameter estimations. It was estimated to be 5-14% (w/w) of the measured volatile suspended solids concentration in the reactor....

  7. Semi-empirical modelling for forest above ground biomass estimation using hybrid and fully PolSAR data

    Science.gov (United States)

    Tomar, Kiledar S.; Kumar, Shashi; Tolpekin, Valentyn A.; Joshi, Sushil K.

    2016-05-01

    Forests act as sink of carbon and as a result maintains carbon cycle in atmosphere. Deforestation leads to imbalance in global carbon cycle and changes in climate. Hence estimation of forest biophysical parameter like biomass becomes a necessity. PolSAR has the ability to discriminate the share of scattering element like surface, double bounce and volume scattering in a single SAR resolution cell. Studies have shown that volume scattering is a significant parameter for forest biophysical characterization which mainly occurred from vegetation due to randomly oriented structures. This random orientation of forest structure causes shift in orientation angle of polarization ellipse which ultimately disturbs the radar signature and shows overestimation of volume scattering and underestimation of double bounce scattering after decomposition of fully PolSAR data. Hybrid polarimetry has the advantage of zero POA shift due to rotational symmetry followed by the circular transmission of electromagnetic waves. The prime objective of this study was to extract the potential of Hybrid PolSAR and fully PolSAR data for AGB estimation using Extended Water Cloud model. Validation was performed using field biomass. The study site chosen was Barkot Forest, Uttarakhand, India. To obtain the decomposition components, m-alpha and Yamaguchi decomposition modelling for Hybrid and fully PolSAR data were implied respectively. The RGB composite image for both the decomposition techniques has generated. The contribution of all scattering from each plot for m-alpha and Yamaguchi decomposition modelling were extracted. The R2 value for modelled AGB and field biomass from Hybrid PolSAR and fully PolSAR data were found 0.5127 and 0.4625 respectively. The RMSE for Hybrid and fully PolSAR between modelled AGB and field biomass were 63.156 (t ha-1) and 73.424 (t ha-1) respectively. On the basis of RMSE and R2 value, this study suggests Hybrid PolSAR decomposition modelling to retrieve scattering

  8. Biomass burning emissions of reactive gases estimated from satellite data analysis and ecosystem modeling for the Brazilian Amazon region

    Science.gov (United States)

    Potter, Christopher; Brooks-Genovese, Vanessa; Klooster, Steven; Torregrosa, Alicia

    2002-10-01

    To produce a new daily record of trace gas emissions from biomass burning events for the Brazilian Legal Amazon, we have combined satellite advanced very high resolution radiometer (AVHRR) data on fire counts together for the first time with vegetation greenness imagery as inputs to an ecosystem biomass model at 8 km spatial resolution. This analysis goes beyond previous estimates for reactive gas emissions from Amazon fires, owing to a more detailed geographic distribution estimate of vegetation biomass, coupled with daily fire activity for the region (original 1 km resolution), and inclusion of fire effects in extensive areas of the Legal Amazon (defined as the Brazilian states of Acre, Amapá, Amazonas, Maranhao, Mato Grosso, Pará, Rondônia, Roraima, and Tocantins) covered by open woodland, secondary forests, savanna, and pasture vegetation. Results from our emissions model indicate that annual emissions from Amazon deforestation and biomass burning in the early 1990s total to 102 Tg yr-1 carbon monoxide (CO) and 3.5 Tg yr-1 nitrogen oxides (NOx). Peak daily burning emissions, which occurred in early September 1992, were estimated at slightly more than 3 Tg d-1for CO and 0.1 Tg d-1for NOx flux to the atmosphere. Other burning source fluxes of gases with relatively high emission factors are reported, including methane (CH4), nonmethane hydrocarbons (NMHC), and sulfur dioxide (SO2), in addition to total particulate matter (TPM). We estimate the Brazilian Amazon region to be a source of between one fifth and one third for each of these global emission fluxes to the atmosphere. The regional distribution of burning emissions appears to be highest in the Brazilian states of Maranhao and Tocantins, mainly from burning outside of moist forest areas, and in Pará and Mato Grosso, where we identify important contributions from primary forest cutting and burning. These new daily emission estimates of reactive gases from biomass burning fluxes are designed to be used as

  9. Estimation of the fate of microbial water-quality contaminants in a South-African river

    CSIR Research Space (South Africa)

    Hohls, D

    1995-01-01

    Full Text Available The aim of this study was to evaluate the validity of assumptions, regarding assimilative capacity for microbial contaminants, implicit in microbial water quality management in South Africa. A one dimensional steady state stream water quality model...

  10. Beak measurements of octopus ( Octopus variabilis) in Jiaozhou Bay and their use in size and biomass estimation

    Science.gov (United States)

    Xue, Ying; Ren, Yiping; Meng, Wenrong; Li, Long; Mao, Xia; Han, Dongyan; Ma, Qiuyun

    2013-09-01

    Cephalopods play key roles in global marine ecosystems as both predators and preys. Regressive estimation of original size and weight of cephalopod from beak measurements is a powerful tool of interrogating the feeding ecology of predators at higher trophic levels. In this study, regressive relationships among beak measurements and body length and weight were determined for an octopus species ( Octopus variabilis), an important endemic cephalopod species in the northwest Pacific Ocean. A total of 193 individuals (63 males and 130 females) were collected at a monthly interval from Jiaozhou Bay, China. Regressive relationships among 6 beak measurements (upper hood length, UHL; upper crest length, UCL; lower hood length, LHL; lower crest length, LCL; and upper and lower beak weights) and mantle length (ML), total length (TL) and body weight (W) were determined. Results showed that the relationships between beak size and TL and beak size and ML were linearly regressive, while those between beak size and W fitted a power function model. LHL and UCL were the most useful measurements for estimating the size and biomass of O. variabilis. The relationships among beak measurements and body length (either ML or TL) were not significantly different between two sexes; while those among several beak measurements (UHL, LHL and LBW) and body weight (W) were sexually different. Since male individuals of this species have a slightly greater body weight distribution than female individuals, the body weight was not an appropriate measurement for estimating size and biomass, especially when the sex of individuals in the stomachs of predators was unknown. These relationships provided essential information for future use in size and biomass estimation of O. variabilis, as well as the estimation of predator/prey size ratios in the diet of top predators.

  11. Microbial Impacts to the Near-Field Environment Geochemistry (MING): A Model for Estimating Microbial Communities in Repository Drifts at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    D.M. Jolley; T.F. Ehrhorn; J. Horn

    2002-03-19

    Geochemical and microbiological modeling was performed to evaluate the potential quantities and impact of microorganisms on the geochemistry of the area adjacent to and within nuclear waste packages in the proposed repository drifts at Yucca Mountain, Nevada. The microbial growth results from the introduction of water, ground support, and waste package materials into the deep unsaturated rock. The simulations, which spanned one million years, were accomplished using a newly developed computer code, Microbial Impacts to the Near-Field Environment Geochemistry (MING). MING uses environmental thresholds for limiting microbial growth to temperatures below 120 C and above relative humidities of 90 percent in repository drifts. Once these thresholds are met, MING expands upon a mass balance and thermodynamic approach proposed by McKinley and others (1997), by using kinetic rates to supply constituents from design materials and constituent fluxes including solubilized rock components into the drift, to perform two separate mass-balance calculations as a function of time. The first (nutrient limit) assesses the available nutrients (C, N, P and S) and calculates how many microorganisms can be produced based on a microorganism stoichiometry of C{sub 160}(H{sub 280}O{sub 80})N{sub 30}P{sub 2}S. The second (energy limit) calculates the energy available from optimally combined redox couples for the temperature, and pH at that time. This optimization maximizes those reactions that produce > 15kJ/mol (limit on useable energy) using an iterative linear optimization technique. The final available energy value is converted to microbial mass at a rate of 1 kg of biomass (dry weight) for every 64 MJ of energy. These two values (nutrient limit and energy limit) are then compared and the smaller value represents the number of microorganisms that can be produced over a specified time. MING can also be adapted to investigate other problems of interest as the model can be used in saturated

  12. Microbial Impacts to the Near-Field Environment Geochemistry (MING): A Model for Estimating Microbial Communities in Repository Drifts at Yucca Mountain

    International Nuclear Information System (INIS)

    Jolley, D.M.; Ehrhorn, T.F.; Horn, J.

    2002-01-01

    Geochemical and microbiological modeling was performed to evaluate the potential quantities and impact of microorganisms on the geochemistry of the area adjacent to and within nuclear waste packages in the proposed repository drifts at Yucca Mountain, Nevada. The microbial growth results from the introduction of water, ground support, and waste package materials into the deep unsaturated rock. The simulations, which spanned one million years, were accomplished using a newly developed computer code, Microbial Impacts to the Near-Field Environment Geochemistry (MING). MING uses environmental thresholds for limiting microbial growth to temperatures below 120 C and above relative humidities of 90 percent in repository drifts. Once these thresholds are met, MING expands upon a mass balance and thermodynamic approach proposed by McKinley and others (1997), by using kinetic rates to supply constituents from design materials and constituent fluxes including solubilized rock components into the drift, to perform two separate mass-balance calculations as a function of time. The first (nutrient limit) assesses the available nutrients (C, N, P and S) and calculates how many microorganisms can be produced based on a microorganism stoichiometry of C 160 (H 280 O 80 )N 30 P 2 S. The second (energy limit) calculates the energy available from optimally combined redox couples for the temperature, and pH at that time. This optimization maximizes those reactions that produce > 15kJ/mol (limit on useable energy) using an iterative linear optimization technique. The final available energy value is converted to microbial mass at a rate of 1 kg of biomass (dry weight) for every 64 MJ of energy. These two values (nutrient limit and energy limit) are then compared and the smaller value represents the number of microorganisms that can be produced over a specified time. MING can also be adapted to investigate other problems of interest as the model can be used in saturated and unsaturated

  13. The feasibility of remotely sensed data to estimate urban tree dimensions and biomass

    Science.gov (United States)

    Jun-Hak Lee; Yekang Ko; E. Gregory McPherson

    2016-01-01

    Accurately measuring the biophysical dimensions of urban trees, such as crown diameter, stem diameter, height, and biomass, is essential for quantifying their collective benefits as an urban forest. However, the cost of directly measuring thousands or millions of individual trees through field surveys can be prohibitive. Supplementing field surveys with remotely sensed...

  14. Evaluating the remote sensing and inventory-based estimation of biomass in the western Carpathians

    Science.gov (United States)

    Magdalena Main-Knorn; Gretchen G. Moisen; Sean P. Healey; William S. Keeton; Elizabeth A. Freeman; Patrick Hostert

    2011-01-01

    Understanding the potential of forest ecosystems as global carbon sinks requires a thorough knowledge of forest carbon dynamics, including both sequestration and fluxes among multiple pools. The accurate quantification of biomass is important to better understand forest productivity and carbon cycling dynamics. Stand-based inventories (SBIs) are widely used for...

  15. Impacts of communal fuelwood extraction on lidar-estimated biomass patterns of savanna woodlands

    CSIR Research Space (South Africa)

    Wessels, Konrad J

    2012-07-01

    Full Text Available Approximately 54% of rural households in South Africa continue to use wood as their main source of energy, mainly for cooking and heating. The provision of biomass by savanna woodlands is thus of considerable value to rural households and therefore...

  16. Validity of zooplankton biomass estimates and energy equivalent in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Dalal, S.G.; Parulekar, A.H.

    , as deduced from the data on biochemical composition and energy content, it is evident that zooplankton of the Indian Ocean contains on an average 2.7% organic carbon, rather than the widely quoted value of 6.5%. The biomass production in terms of organic...

  17. Satellite detection of land-use change and effects on regional forest aboveground biomass estimates

    Science.gov (United States)

    Daolan Zheng; Linda S. Heath; Mark J. Ducey

    2008-01-01

    We used remote-sensing-driven models to detect land-cover change effects on forest aboveground biomass (AGB) density (Mg·ha−1, dry weight) and total AGB (Tg) in Minnesota, Wisconsin, and Michigan USA, between the years 1992-2001, and conducted an evaluation of the approach. Inputs included remotely-sensed 1992 reflectance data...

  18. Comparison of different approaches of radiation use efficiency of biomass formation estimation in Mountain Norway spruce

    Czech Academy of Sciences Publication Activity Database

    Krupková, Lenka; Marková, I.; Havránková, Kateřina; Pokorný, Radek; Urban, Otmar; Šigut, Ladislav; Pavelka, Marian; Cienciala, E.; Marek, Michal V.

    2017-01-01

    Roč. 31, č. 1 (2017), s. 325-337 ISSN 0931-1890 R&D Projects: GA MŠk(CZ) LO1415; GA MŠk(CZ) LM2015061 Institutional support: RVO:67179843 Keywords : Solar radiation * Biomass increment * Carbon flux * light use efficiency Subject RIV: GK - Forestry OBOR OECD: Forestry Impact factor: 1.842, year: 2016

  19. Use of in vivo chlorophyll fluorescence to estimate photosynthetic activity and biomass productivity in microalgae grown in different culture systems

    Directory of Open Access Journals (Sweden)

    Félix L Figueroa

    2013-11-01

    Full Text Available In vivo chlorophyll fluorescence associated to Photosystem II is being used to evaluate photosynthetic activity of microalgae grown in different types of photobioreactors; however, controversy on methodology is usual. Several recommendations on the use of chlorophyll fluorescence to estimate electron transport rate and productivity of microalgae grown in thin-layer cascade cultivators and methacrylate cylindrical vessels are included. Different methodologies related to the measure of photosynthetic activity in microalgae are discussed: (1 measurement of light absorption, (2 determination of electron transport rates versus irradiance and (3 use of simplified devices based on pulse amplitude modulated (PAM fluorescence as Junior PAM or Pocket PAM with optical fiber and optical head as measuring units, respectively. Data comparisons of in vivo chlorophyll fluorescence by using these devices and other PAM fluorometers as Water-PAM in the microalga Chlorella sp. (Chlorophyta are presented. Estimations of carbon production and productivity by transforming electron transport rate to gross photosynthetic rate (as oxygen evolution using reported oxygen produced per photons absorbed values and carbon photosynthetic yield based on reported oxygen/carbon ratio are also shown. The limitation of ETR as estimator of photosynthetic and biomass productivity is discussed. Low cost:quality PAMs can promote monitoring of chlorophyll fluorescence in algal biotechnology to estimate the photosynthetic activity and biomass productivity.

  20. Fractionation of phosphorus added as a vegetal residue (32 P) and a fertilizer (32 P) between soil, plant and microbial biomass

    International Nuclear Information System (INIS)

    Pereira, M.C.

    1988-04-01

    Sugar cane straw and/or P-fertilizer phosphorus-32 labelled were added to a Red Yellow podzolic soil from Goiana-PE. The treated samples were used in a pot experiment, growing sorghum plants for 4 and 6 weeks, and in an incubation experiment with incubation periods of 1, 2, 3, 4 and 6 weeks without plants in order to follow the dynamics of the P added. After each harvest and incubation period the soil were analysed for 31 P and 32 P in the microbial biomass and in sequential extracts with resin (Pi), 0.5 M Na H Co 3 (Pi, Po) and 0.1 N NaOH (Pi, Po). The 31 P and 32 P contents of the sorghum in the pot experiment were also determined. (author)

  1. Urease activity and its relation to soil organic matter, microbial biomass nitrogen and urea-nitrogen assimilation by maize in a Brazilian oxisol under no-tillage and tillage systems

    NARCIS (Netherlands)

    Roscoe, R.; Vasconcellos, C.A.; Furtini Neto, A.E.; Guedes, G.A.A.; Fernandes, L.A.

    2000-01-01

    We studied the relationship between urease activity (UA) and soil organic matter (SOM), microbial biomass N (Nbiom) content, and urea-N fertilizer assimilation by maize in a Dark Red Latosol (Typic Haplustox) cultivated for 9 years under no-tillage (NT), tillage with a disc plough (DP), and tillage

  2. Evaluation of optimum roughage to concentrate ratio in maize stover based complete rations for efficient microbial biomass production using in vitro gas production technique

    Directory of Open Access Journals (Sweden)

    Y. Ramana Reddy

    2016-06-01

    Full Text Available Aim: A study was undertaken to evaluate the optimum roughage to concentrate ratio in maize stover (MS based complete diets for efficient microbial biomass production (EMBP using in vitro gas production technique. Materials and Methods: MS based complete diets with roughage to concentrate ratio of 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, and 30:70 were formulated, and 200 mg of oven-dried sample was incubated in water bath at 39°C along with media (rumen liquor [RL] - buffer in in vitro gas syringes to evaluate the gas production. The gas produced was recorded at 8 and 24 h of inc ubation. In vitro organic matter digestibility (IVOMD, metabolizable energy (ME, truly digestible organic matter (TDOM, partitioning factor (PF, and EMBP were calculated using appropriate formulae. Ammonia nitrogen and total volatile fatty acids (TVFAs production were analyzed in RL fluid-media mixture after 24 h of incubation. Results: In vitro gas production (ml at 24 h incubation, IVOMD, ME, TDOM, TVFA concentration, and ammonia nitrogen production were increased (p<0.01 in proportion to the increase in the level of concentrate in the diet. Significantly (p<0.01 higher PF and EMBP was noticed in total mixed ration with roughage to concentrate ratio of 60:40 and 50:50 followed by 70:30 and 40:60. Conclusion: Based on the results, it was concluded that the MS can be included in complete rations for ruminants at the level of 50-60% for better microbial biomass synthesis which in turn influences the performance of growing sheep.

  3. Evaluation of optimum roughage to concentrate ratio in maize stover based complete rations for efficient microbial biomass production using in vitro gas production technique.

    Science.gov (United States)

    Reddy, Y Ramana; Kumari, N Nalini; Monika, T; Sridhar, K

    2016-06-01

    A study was undertaken to evaluate the optimum roughage to concentrate ratio in maize stover (MS) based complete diets for efficient microbial biomass production (EMBP) using in vitro gas production technique. MS based complete diets with roughage to concentrate ratio of 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, and 30:70 were formulated, and 200 mg of oven-dried sample was incubated in water bath at 39°C along with media (rumen liquor [RL] - buffer) in in vitro gas syringes to evaluate the gas production. The gas produced was recorded at 8 and 24 h of incubation. In vitro organic matter digestibility (IVOMD), metabolizable energy (ME), truly digestible organic matter (TDOM), partitioning factor (PF), and EMBP were calculated using appropriate formulae. Ammonia nitrogen and total volatile fatty acids (TVFAs) production were analyzed in RL fluid-media mixture after 24 h of incubation. In vitro gas production (ml) at 24 h incubation, IVOMD, ME, TDOM, TVFA concentration, and ammonia nitrogen production were increased (p<0.01) in proportion to the increase in the level of concentrate in the diet. Significantly (p<0.01) higher PF and EMBP was noticed in total mixed ration with roughage to concentrate ratio of 60:40 and 50:50 followed by 70:30 and 40:60. Based on the results, it was concluded that the MS can be included in complete rations for ruminants at the level of 50-60% for better microbial biomass synthesis which in turn influences the performance of growing sheep.

  4. Development of Equation Based on Urinary Purine Derivatives to Estimate Rumen Microbial Protein Production in Goats

    International Nuclear Information System (INIS)

    Jetana, Thongsuk; Abdullah, Norhani; Liang, Boo Juan; Syed Salim, Syed Jalaludin; Ho, Wan Yin

    2003-06-01

    Three experiments were conducted at the farm of the Universiti Putra Malaysia, Serdang, Selangor, Malaysia, to establish a model as an index for estimating rumen microbial protein production. In Experiment 1, six Ferral male goats (wt. 40.2±4.6 kg) were used to determine the endogenous purine derivatives (PD) excreted in the urine by fasting. In Experiment 2, four Ferral male goats (wt. 39.6±1.8 kg) were used to measure the proportion of plasma PD excreted in the urine by using [ 14 C]-uric acid as a marker at two levels of feed intake (40% and 80% voluntary intake), using an incomplete 2x4 Latin square experimental design. The feed consisted of 40% oil palm frond and 60% concentrate (OPFC). In Experiment 3, four Ferral male goats fed (OPFC)) were slaughtered and rumen contents were taken for measurements of purine and total nitrogen contents of mixed rumen microbes. The results showed that endogenous PD (allantoin, uric acid, xanthine and hypoxanthine) excreted in the urine obtained by the fasting trial was 202±17 μmol/kg BW 0 . 75 d - 1. The average percentage recovery of plasma PD excretion in the urine by using [ 14 C)-uric acid as a marker was 83±2.0% (cv=6.88, ranged 76.3-91.4%, n=8). Percentage recovery was not affected by levels of feed intake. The ratio of purine N: total N in the mixed rumen liquid associated bacteria (LAB) was 0.085. In this study, a preliminary model for goats was established by using the information from the recovery of labeled PD [ 14 C]-uric acid and the fasting PD excretion. The model obtained was Y 0.83X + 0.202 x BW 0 . 75 , where Y = PD excretion in the urine (mmol/d) X PD absorption at small intestine (mmol/d) BW 0 . 75 = Metabolic body weight (kg) Thus the microbial nitrogen based on total PD (MNpd) can be calculated as follows: MNpd = 70 x X = 0.992 x X (g/d) 0.085 x 0.83 x 1000 where 0.085 is the ratio of purine-N: total N in mixed rumen microbes, 0.83 is the average of digestibility of microbial purine from published

  5. Biomass estimates of freshwater zooplankton from length-carbon regression equations

    Directory of Open Access Journals (Sweden)

    Patrizia COMOLI

    2000-02-01

    Full Text Available We present length/carbon regression equations of zooplankton species collected from Lake Maggiore (N. Italy during 1992. The results are discussed in terms of the environmental factors, e.g. food availability, predation, controlling biomass production of particle- feeders and predators in the pelagic system of lakes. The marked seasonality in the length-standardized carbon content of Daphnia, and its time-specific trend suggest that from spring onward food availability for Daphnia population may be regarded as a simple decay function. Seasonality does not affect the carbon content/unit length of the two predator Cladocera Leptodora kindtii and Bythotrephes longimanus. Predation is probably the most important regulating factor for the seasonal dynamics of their carbon biomass. The existence of a constant factor to convert the diameter of Conochilus colonies into carbon seems reasonable for an organism whose population comes on quickly and just as quickly disappears.

  6. The GAAS Metagenomic Tool and Its Estimations of Viral and Microbial Average Genome Size in Four Major Biomes

    OpenAIRE

    Angly, Florent E.; Willner, Dana; Prieto-Dav?, Alejandra; Edwards, Robert A.; Schmieder, Robert; Vega-Thurber, Rebecca; Antonopoulos, Dionysios A.; Barott, Katie; Cottrell, Matthew T.; Desnues, Christelle; Dinsdale, Elizabeth A.; Furlan, Mike; Haynes, Matthew; Henn, Matthew R.; Hu, Yongfei

    2009-01-01

    Metagenomic studies characterize both the composition and diversity of uncultured viral and microbial communities. BLAST-based comparisons have typically been used for such analyses; however, sampling biases, high percentages of unknown sequences, and the use of arbitrary thresholds to find significant similarities can decrease the accuracy and validity of estimates. Here, we present Genome relative Abundance and Average Size (GAAS), a complete software package that provides improved estimate...

  7. Bioenergy in Australia: An improved approach for estimating spatial availability of biomass resources in the agricultural production zones

    International Nuclear Information System (INIS)

    Herr, Alexander; Dunlop, Michael

    2011-01-01

    Bioenergy production from crops and agricultural residues has a greenhouse gas mitigation potential. However, there is considerable debate about the size of this potential. This is partly due to difficulties in estimating the feedstock resource base accurately and with good spatial resolution. Here we provide two techniques for spatially estimating crop-based bioenergy feedstocks in Australia using regional agricultural statistics and national land use maps. The approach accommodates temporal variability by estimating ranges of feedstock availability and the shifting nature of zones of the highest spatial concentration of feedstocks. The techniques are applicable to biomass production from forestry, agricultural residues or oilseeds, all of which have been proposed as biofuel feedstocks. -- Highlights: → Dasymetric mapping appoach for producing spatial and temporal variation maps in feedstock production.→ Combines land use and crop statistics to produce regionally precise feedstock maps. → Feedstock concentrations and feedstock density maps enable identification of feedstock concentration spatially and comparison of yearly variation in production.

  8. Examining effective use of data sources and modeling algorithms for improving biomass estimation in a moist tropical forest of the Brazilian Amazon

    Science.gov (United States)

    Yunyun Feng; Dengsheng Lu; Qi Chen; Michael Keller; Emilio Moran; Maiza Nara dos-Santos; Edson Luis Bolfe; Mateus Batistella

    2017-01-01

    Previous research has explored the potential to integrate lidar and optical data in aboveground biomass (AGB) estimation, but how different data sources, vegetation types, and modeling algorithms influence AGB estimation is poorly understood. This research conducts a comparative analysis of different data sources and modeling approaches in improving AGB estimation....

  9. Aboveground Biomass Estimation Using Reconstructed Feature of Airborne Discrete-Return LIDAR by Auto-Encoder Neural Network

    Science.gov (United States)

    Li, T.; Wang, Z.; Peng, J.

    2018-04-01

    Aboveground biomass (AGB) estimation is critical for quantifying carbon stocks and essential for evaluating carbon cycle. In recent years, airborne LiDAR shows its great ability for highly-precision AGB estimation. Most of the researches estimate AGB by the feature metrics extracted from the canopy height distribution of the point cloud which calculated based on precise digital terrain model (DTM). However, if forest canopy density is high, the probability of the LiDAR signal penetrating the canopy is lower, resulting in ground points is not enough to establish DTM. Then the distribution of forest canopy height is imprecise and some critical feature metrics which have a strong correlation with biomass such as percentiles, maximums, means and standard deviations of canopy point cloud can hardly be extracted correctly. In order to address this issue, we propose a strategy of first reconstructing LiDAR feature metrics through Auto-Encoder neural network and then using the reconstructed feature metrics to estimate AGB. To assess the prediction ability of the reconstructed feature metrics, both original and reconstructed feature metrics were regressed against field-observed AGB using the multiple stepwise regression (MS) and the partial least squares regression (PLS) respectively. The results showed that the estimation model using reconstructed feature metrics improved R2 by 5.44 %, 18.09 %, decreased RMSE value by 10.06 %, 22.13 % and reduced RMSEcv by 10.00 %, 21.70 % for AGB, respectively. Therefore, reconstructing LiDAR point feature metrics has potential for addressing AGB estimation challenge in dense canopy area.

  10. Evaluation of Radiometric and Atmospheric Correction Algorithms for Aboveground Forest Biomass Estimation Using Landsat 5 TM Data

    Directory of Open Access Journals (Sweden)

    Pablito M. López-Serrano

    2016-04-01

    Full Text Available Solar radiation is affected by absorption and emission phenomena during its downward trajectory from the Sun to the Earth’s surface and during the upward trajectory detected by satellite sensors. This leads to distortion of the ground radiometric properties (reflectance recorded by satellite images, used in this study to estimate aboveground forest biomass (AGB. Atmospherically-corrected remote sensing data can be used to estimate AGB on a global scale and with moderate effort. The objective of this study was to evaluate four atmospheric correction algorithms (for surface reflectance, ATCOR2 (Atmospheric Correction for Flat Terrain, COST (Cosine of the Sun Zenith Angle, FLAASH (Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes and 6S (Second Simulation of Satellite Signal in the Solar, and one radiometric correction algorithm (for reflectance at the sensor ToA (Apparent Reflectance at the Top of Atmosphere to estimate AGB in temperate forest in the northeast of the state of Durango, Mexico. The AGB was estimated from Landsat 5 TM imagery and ancillary information from a digital elevation model (DEM using the non-parametric multivariate adaptive regression splines (MARS technique. Field reference data for the model training were collected by systematic sampling of 99 permanent forest growth and soil research sites (SPIFyS established during the winter of 2011. The following predictor variables were identified in the MARS model: Band 7, Band 5, slope (β, Wetness Index (WI, NDVI and MSAVI2. After cross-validation, 6S was found to be the optimal model for estimating AGB (R2 = 0.71 and RMSE = 33.5 Mg·ha−1; 37.61% of the average stand biomass. We conclude that atmospheric and radiometric correction of satellite images can be used along with non-parametric techniques to estimate AGB with acceptable accuracy.

  11. Biogas Production from Protein-Rich Biomass: Fed-Batch Anaerobic Fermentation of Casein and of Pig Blood and Associated Changes in Microbial Community Composition

    Science.gov (United States)

    Kovács, Etelka; Wirth, Roland; Maróti, Gergely; Bagi, Zoltán; Rákhely, Gábor; Kovács, Kornél L.

    2013-01-01

    It is generally accepted as a fact in the biogas technology that protein-rich biomass substrates should be avoided due to inevitable process inhibition. Substrate compositions with a low C/N ratio are considered difficult to handle and may lead to process failure, though protein-rich industrial waste products have outstanding biogas generation potential. This common belief has been challenged by using protein-rich substrates, i.e. casein and precipitated pig blood protein in laboratory scale continuously stirred mesophilic fed-batch biogas fermenters. Both substrates proved suitable for sustained biogas production (0.447 L CH4/g protein oDM, i.e. organic total solids) in high yield without any additives, following a period of adaptation of the microbial community. The apparent key limiting factors in the anaerobic degradation of these proteinaceous materials were the accumulation of ammonia and hydrogen sulfide. Changes in time in the composition of the microbiological community were determined by next-generation sequencing-based metagenomic analyses. Characteristic rearrangements of the biogas-producing community upon protein feeding and specific differences due to the individual protein substrates were recognized. The results clearly demonstrate that sustained biogas production is readily achievable, provided the system is well-characterized, understood and controlled. Biogas yields (0.45 L CH4/g oDM) significantly exceeding those of the commonly used agricultural substrates (0.25-0.28 L CH4/g oDM) were routinely obtained. The results amply reveal that these high-energy-content waste products can be converted to biogas, a renewable energy carrier with flexible uses that can replace fossil natural gas in its applications. Process control, with appropriate acclimation of the microbial community to the unusual substrate, is necessary. Metagenomic analysis of the microbial community by next-generation sequencing allows a precise determination of the alterations in

  12. Biogas production from protein-rich biomass: fed-batch anaerobic fermentation of casein and of pig blood and associated changes in microbial community composition.

    Directory of Open Access Journals (Sweden)

    Etelka Kovács

    Full Text Available It is generally accepted as a fact in the biogas technology that protein-rich biomass substrates should be avoided due to inevitable process inhibition. Substrate compositions with a low C/N ratio are considered difficult to handle and may lead to process failure, though protein-rich industrial waste products have outstanding biogas generation potential. This common belief has been challenged by using protein-rich substrates, i.e. casein and precipitated pig blood protein in laboratory scale continuously stirred mesophilic fed-batch biogas fermenters. Both substrates proved suitable for sustained biogas production (0.447 L CH4/g protein oDM, i.e. organic total solids in high yield without any additives, following a period of adaptation of the microbial community. The apparent key limiting factors in the anaerobic degradation of these proteinaceous materials were the accumulation of ammonia and hydrogen sulfide. Changes in time in the composition of the microbiological community were determined by next-generation sequencing-based metagenomic analyses. Characteristic rearrangements of the biogas-producing community upon protein feeding and specific differences due to the individual protein substrates were recognized. The results clearly demonstrate that sustained biogas production is readily achievable, provided the system is well-characterized, understood and controlled. Biogas yields (0.45 L CH4/g oDM significantly exceeding those of the commonly used agricultural substrates (0.25-0.28 L CH4/g oDM were routinely obtained. The results amply reveal that these high-energy-content waste products can be converted to biogas, a renewable energy carrier with flexible uses that can replace fossil natural gas in its applications. Process control, with appropriate acclimation of the microbial community to the unusual substrate, is necessary. Metagenomic analysis of the microbial community by next-generation sequencing allows a precise determination of the

  13. Microbial biomass, microbial diversity, soil carbon storage, and stability after incubation of soil from grass-clover pastures of different age

    DEFF Research Database (Denmark)

    Müller-Stöver, Dorette Sophie; Hauggaard-Nielsen, Henrik; Eriksen, Jørgen

    2012-01-01

    A laboratory incubation study with clover grass pasture soils of seven different ages (0, 1, 2, 3, 4, 5, and 16 production years) was carried out to determine initial soil carbon (C) and nitrogen (N) stocks and potentials for greenhouse gas emissions (N2O and CO2). Compared with the soil from...... the recently established pasture, an increase of total soil C and N was observed along with pasture age. Greenhouse gas emissions were low and not significantly different among the soils from younger pastures (0-5 years), but especially N2O emissions increased markedly in the soil from 16-year-old grass......-clover. Low emissions might mainly be due to an early C limitation occurring in the soils from younger pastures, which was also corroborated by decreasing levels of cold water-extractable C and early shifts within the microbial community. However, higher emissions from the old pasture soil were offset by its...

  14. Microbial biomass and organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Sheelu, G.; LokaBharathi, P.A.; Nair, S.; Mohandass, C.

    PMNprogramoftheDepartmentofOceanDevelopment,GovernmentofIndia.TheauthorsarethankfultothescientistsandcrewAASidorentzoforcooperationandassistanceduringthelongcruisesinthesamplingarea.The authorsalsowishtothankMs.GowriRivonkarfortechnicalassistanceinthelaboratory.NIOContributionNo.3509.ThispaperispartoftheseriespublishedinthespecialissueofMarineGeoresourcesandGeotechnology,Volume18,Number3,2000. AddresscorrespondencetoChandralataRaghukumar,NationalInstituteof...%)wastwotimesmorethanthatofthe MicrobialBiomassandOrganicNutrientsinCIOB 9 Figure4.(a)± (e)ConcentrationofLOM,TOC,andlivingbiomass-Cin® vecoresatdiŒerentdepths. bacterialisolates(34%).Ontheotherhand,numberofbacterialisolatesproducingproteasewere2.5timesmorethanthefungalisolates...

  15. Mixed-species allometric equations and estimation of aboveground biomass and carbon stocks in restoring degraded landscape in northern Ethiopia

    Science.gov (United States)

    Mokria, Mulugeta; Mekuria, Wolde; Gebrekirstos, Aster; Aynekulu, Ermias; Belay, Beyene; Gashaw, Tadesse; Bräuning, Achim

    2018-02-01

    Accurate biomass estimation is critical to quantify the changes in biomass and carbon stocks following the restoration of degraded landscapes. However, there is lack of site-specific allometric equations for the estimation of aboveground biomass (AGB), which consequently limits our understanding of the contributions of restoration efforts in mitigating climate change. This study was conducted in northwestern Ethiopia to develop a multi-species allometric equation and investigate the spatial and temporal variation of C-stocks following the restoration of degraded landscapes. We harvested and weighed 84 trees from eleven dominant species from six grazing exclosures and adjacent communal grazing land. We observed that AGB correlates significantly with diameter at stump height D 30 (R 2 = 0.78 P < 0.01), and tree height H (R 2 = 0.41, P < 0.05). Our best model, which includes D 30 and H as predictors explained 82% of the variations in AGB. This model produced the lowest bias with narrow ranges of errors across different diameter classes. Estimated C-stock showed a significant positive correlation with stem density (R 2 = 0.80, P < 0.01) and basal area (R 2 = 0.84, P < 0.01). At the watershed level, the mean C-stock was 3.8 (±0.5) Mg C ha-1. Plot-level C-stocks varied between 0.1 and 13.7 Mg C ha-1. Estimated C-stocks in three- and seven-year-old exclosures exceeded estimated C-stock in the communal grazing land by 50%. The species that contribute most to C-stocks were Leucaena sp. (28%), Calpurnia aurea (21%), Euclea racemosa (20.9%), and Dodonaea angustifolia (15.8%). The equations developed in this study allow monitoring changes in C-stocks and C-sequestration following the implementation of restoration practices in northern Ethiopia over space and time. The estimated C-stocks can be used as a reference against which future changes in C-stocks can be compared.

  16. Estimating above-ground biomass on mountain meadows and pastures through remote sensing

    Science.gov (United States)

    Barrachina, M.; Cristóbal, J.; Tulla, A. F.

    2015-06-01

    Extensive stock-breeding systems developed in mountain areas like the Pyrenees are crucial for local farming economies and depend largely on above-ground biomass (AGB) in the form of grass produced on meadows and pastureland. In this study, a multiple linear regression analysis technique based on in-situ biomass collection and vegetation and wetness indices derived from Landsat-5 TM data is successfully applied in a mountainous Pyrenees area to model AGB. Temporal thoroughness of the data is ensured by using a large series of images. Results of on-site AGB collection show the importance for AGB models to capture the high interannual and intraseasonal variability that results from both meteorological conditions and farming practices. AGB models yield best results at midsummer and end of summer before mowing operations by farmers, with a mean R2, RMSE and PE for 2008 and 2009 midsummer of 0.76, 95 g m-2 and 27%, respectively; and with a mean R2, RMSE and PE for 2008 and 2009 end of summer of 0.74, 128 g m-2 and 36%, respectively. Although vegetation indices are a priori more related with biomass production, wetness indices play an important role in modeling AGB, being statistically selected more frequently (more than 50%) than other traditional vegetation indexes (around 27%) such as NDVI. This suggests that middle infrared bands are crucial descriptors of AGB. The methodology applied in this work compares favorably with other works in the literature, yielding better results than those works in mountain areas, owing to the ability of the proposed methodology to capture natural and anthropogenic variations in AGB which are the key to increasing AGB modeling accuracy.

  17. Comparative effects of application of coated and non-coated urea in clayey and sandy paddy soil microcosms examined by the 15N tracer technique. 2. Effects on soil microbial biomass N and microbial 15N immobilization

    International Nuclear Information System (INIS)

    Acquaye, Solomon; Inubushi, Kazuyuki

    2004-01-01

    Nitrogen fertilizer and soil types exert an impact on plant and soil microbial biomass (SMB). A 15 N tracer experiment was conducted to compare the effects of the application of controlled-release coated urea (CRCU) and urea on SMB in gley (clayey) and sandy paddy soils. The fertilizers were applied at the rate of 8 g N m -2 for CRCU as deep-side placement and 10 g N m -2 for urea mixed into soil or applied into floodwater. The soil type and soil layer (surface: few millimeter depth of surface soil to include benthic algae; subsurface: 1 to 20 cm depth), but not the fertilizer type, affected the amount of microbial biomass N (B N ). On an area basis, subsurface soil layers contained about 2-3 times the amount of B N in the surface layers. The seasonal average B N amount i.e. at 1 to 20 cm depth, in the gley soil was 1.67 g N m -2 , compared to 1.20 g N m -2 for the sandy soil. The proportion of B N in total soil N was significantly influenced by the soil type and soil layer, and was higher for the surface layers of both soils and subsurface layer of the sandy soil than for the subsurface layer of gley soil. Soil type, soil layer, and fertilizer type significantly influenced the amount of microbial biomass 15 N (B 15N ). Unlike B N , the amount of B 15N was significantly higher in the surface (11.9-177.3 mg N m -2 ) than in the subsurface soil layers (4.8-83.6 mg N m -2 ), especially with urea application between 60 and 120 DAT (days after transplanting). At 30 DAT, the subsurface layer of the sandy so