Search results for "Biomas"

Carbon use efficiency variability from MODIS data

2017

[EN] Carbon use efficiency (CUE) describes how efficiently plants incorporate the carbon fixed during photosynthesis into biomass gain and can be calculated as the ratio between net primary production (NPP) and gross primary production (GPP). In this work, annual CUE has been obtained from annual GPP and NPP MODIS products for the peninsular Spain study area throughout eight years. CUE is spatially and temporally analyzed in terms of the vegetation type and annual precipitation and annual average air temperature. Results show that dense vegetation areas with moderate to high levels of precipitation present lower CUE values, whereas more arid areas present the highest CUE values. However, th…

Bioagronomic and energy potential of Carthamus tinctorius L. in the Mediterranean area

2011

In recent years, interest in dedicated energy crops, in particular oilseed crops, in the Mediterranean area has risen. This is due both to an increase in energy demand in various sectors and the need to meet the objectives set by the European Union. The agro-energy sector may become an important economic opportunity for farms, especially when considering the use of the whole plant – the oil-rich seeds and the lignocellulosic crop residues. However, in economic terms, further study is needed in the management, quantification and subsequent use of crop residues. This research looks at the productive and energy potential of the seed and crop residues of safflower with the aim of introducing th…

Functional diversity of decomposer organisms in relation to primary production

1998

Abstract The term `biodiversity' is claimed to lack connections to a serious scientific background. In this work, we approached the concept of biodiversity from a functional point of view by asking: “At what level of the ecological organization (species, trophic species/feeding guilds, trophic levels etc.) should reduction in biodiversity matter to bring about visible changes in ecosystem performance?” We investigate the concepts of `functional diversity' and `ecosystem performance' in relation to feeding habits (such as fungivory, detritivory etc.) of soil fauna and plant growth. After analysing the results of a number of microcosm studies, we came into the following conclusions: (i) troph…

Performance of a membrane-coupled high-rate algal pond for urban wastewater treatment at demonstration scale

2020

[EN] The objective of this study was to evaluate the performance of an outdoor membrane-coupled high-rate algal pond equipped with industrial-scale membranes for treating urban wastewater. Decoupling biomass retention time (BRT) and hydraulic retention time (HRT) by membrane filtration resulted in improved process efficiencies, with higher biomass productivities and nutrient removal rates when operating at low HRTs. At 6 days of BRT, biomass productivity increased from 30 to 66 and to 95 g.m(-3).d(-1) when operating at HRTs of 6, 4 and 2.5 days, respectively. The corresponding nitrogen removal rates were 4, 8 and 11 g N.m(-3).d(-1) and the phosphorous removal rates were 0.5, 1.3 and 1.6 g P…

Effect of transition metals and homogeneous hydrogen producers in the hydrothermal liquefaction of sewage sludge

2022

Hydrothermal liquefaction (HTL) of sewage sludge (SS) was performed in the presence of metallic Zn, Fe and Ni to investigate their effect on the performances of the process in terms of product yields and quality. Experiments were performed in subcritical water at 350 ◦C for 10 min using each metal individually and in the presence of homogenous hydrogen producers like formic acid (FA) and KOH. Interesting results were obtained with Zn that when used alone or in the presence of KOH, increased the cumulative biocrude (BC) yields and resulted in energy recoveries (ER) higher than 100% with respect to initial energy content of the biomass, thus indicating that HTL of SS is globally endothermic. …

Eresus kollari (Araneae: Eresidae) calls for heathland management

2011

Northwest Europe’s largest heather-dominated sandy habitats are located in the nature reserve Lu¨neburgerHeide, Germany. Yet, even these appear to be losing their ability to support some of their stenotopic species such as theladybird spider, Eresus kollari Rossi 1846, and are thus becoming increasingly important for the preservation of thesespecies. The habitat requirements of this endangered spider species were investigated in order to obtain data that will helpstabilize the last remnants of the species’ population in northwest Germany. Several heathland habitats were surveyed bypitfall trapping during the mate-search period of the males. Two statistical methods were applied: logistic reg…

Response to reindeer grazing removal depends on soil characteristics in low Arctic meadows

2014

In Arctic tundra, grazing is expected to exert a positive influence on microbial activity thus enhancing nutrient cycling and promoting the presence of high productive graminoids. We investigated the changes occurring in two low Arctic meadow sites after 10 years exclusion from grazing. We compared plant, soil fauna and microbial community composition, extracellular enzymes activities, and soil nutrients in ungrazed and adjacent grazed area in two low Arctic meadows. The two closely located experimental sites were both dominated by the common grass Deschampsia flexuosa which covered more than 50% of the meadows. Plant community was affected significantly by site and grazing, but the effect …

Novel biomass fly ash-based geopolymeric mortars using lime slaker grits as aggregate for applications in construction: Influence of granulometry and…

2019

Abstract This work discusses the influence of the aggregate granulometry and the binder/aggregate ratio on the engineering properties of novel green geopolymeric mortars. Two wastes generated by a Portuguese Kraft pulp industry are employed to manufacture the material: lime slaker grits (used as aggregate) and biomass fly ash (to partially replace the metakaolin − 70 wt% substitution). The novel geopolymeric mortars could find innovative applications as sustainable construction materials. The studied mix design foresees the use of several grits granulometric ranges and ratios binder/aggregate to discuss workability, water sorptivity, and mechanical performance of the novel mortars. To date,…

Potential applications of nanotechnology in bioenergy

2011

Nanotechnology has an increasingly large impact on a wide range of industries, but its current use in the production of electricity and heat from biomass is limited. This thesis examined the potential impact of nanotechnology on bioenergy production through a literature review and interviews with industry members. Current technologies and methods in use were reviewed, with a focus on fuel handling and combustion systems. Areas in which problems existed were identified and nanotechnologies with properties relevant to those problems examined. The major nanotechnology areas which were reviewed are nanostructured coatings (wear resistant, corrosion resistant, low friction and anti-icing), nanom…

2021

Abstract Contaminated soils are lands in Europe deemed less favourable for conventional agriculture. To overcome the problem of their poor fertility, bio-fertilization could be a promising approach. Soil inoculation with a choice of biological species (e.g. earthworm, mycorrhizal fungi, diazotroph bacteria) can be performed in order to improve soil properties and promote nutrients recycling. However, questions arise concerning the dynamics of the contaminants in an inoculated soil. The aim of this study was to highlight the soil-plant-earthworm interactions in the case of a slightly contaminated soil. For this purpose, a pot experiment in controlled conditions was carried out during 2 month…