Production and carbon allocation in a clonal Eucalyptus plantation with water and nutrient manipulations

We examined resource limitations on growth and carbon allocation in a fast-growing, clonal plantation of Eucalyptus grandis x urophylla in Brazil by characterizing responses to annual rainfall, and response to irrigation and fertililization for 2 years. Productivity measures included gross primary production (GPP), total belowground carbon allocation (TBCA), bole growth, and net ecosystem production (NEP). Replicate plots within a single plantation were established at the midpoint of the rotation (end of year 3), with treatments of no additional fertilization or irrigation, heavy fertilization (to remove any nutrient limitation), irrigation (to remove any water limitation), and irrigation plus fertilization. Rainfall was unusually high in the first year (1769mm) of the experiment, and control plots had high rates of GPP (6.64 kg C m(-2) year(-1)), TBCA (2.14 kg C m(-2) year(-1)), and bole growth (1.81 kg C m(-2) year). Irrigation increased each of these rates by 15-17%. The second year of the experiment had average rainfall (1210 mm), and lower rainfall decreased production in control plots by 46% (GPP), 52% (TBCA), and 40% (bole growth). Fertilization treatments had neglible effects. The response to irrigation was much greater in the drier year, with irrigated plots exceeding the production in control plots by 83% (GPP), 239% (TBCA), and 24% (bole growth). Even though the rate of irrigation ensured no water limitation to tree growth, the high rainfall year showed higher production in irrigated plots for both GPP (38% greater than in drier year) and bole growth (23% greater). Varying humidity and supplies of water led to a range in NEP of 0.8-2.7 kg C m(-2) year. This difference between control and irrigated treatments, combined with differences between drier and wetter years, indicated a strong response of these Eucalyptus trees to both water supply and atmospheric humidity during the dry season. The efficiency of converting light energy into fixed carbon ranged from a low of 0.027 mol C to a high of 0.060 mol C per mol of absorbed photosynthetically active radiation (APAR), and the efficiency of bolewood production ranged from 0.78 to 1.98 g wood per MJ of APAR. Irrigation increased the efficiency of wood production per unit of water used from 2.55 kg wood m(-3) in the rainfed plot to 3.51 kg m(-3) in irrigated plots. Detailed information on the response of C budgets to environmental conditions and resource supplies will be necessary for accurate predictions of plantation yields across years and landscapes. (V) 2007 Elsevier B.V. All rights reserved.

Exploration of the acarine fauna on coconut palm in Brazil with emphasis on Aceria guerreronis (Acari : Eriophyidae) and its natural enemies

Coconut is an important crop in tropical and subtropical regions. Among the mites that infest coconut palms, Aceria guerreronis Keifer is economically the most important. We conducted surveys throughout the coconut growing areas of Brazil. Samples were taken from attached coconuts, leaflets, fallen coconuts and inflorescences of coconut palms in 112 localities aiming to determine the Occurrence and the distribution of phytophagous mites, particularly A. guerreronis, and associated natural enemies. Aceria guerreronis was the most abundant phytophagous mite followed by Steneotarsonemus concavuscutum Lofego & Gondim Jr. and Steneotarsonemus furcatus De Leon (Tarsonemidae). Infestation by A. guerreronis was recorded in 87% of the visited localities. About 81% of all predatory mites belonged to the family Phytoseiidae, mainly represented by Neoseiulus paspalivorus De Leon, Neoseiulus baraki Athias-Henriot and Amblyseius largoensis Muma; 12% were Ascidae, mainly Proctolaelaps bickleyi Bram, Proctolaelaps sp nov and Lasioseius subterraneus Chant. Neoseiulus paspalivorus and N. baraki were the most abundant predators on attached coconuts. Ascidae were predominant on fallen coconuts, while A. largoensis was predominant on leaflets; no mites were found on branches of inflorescences. Leaflets harboured higher mite diversity than the attached coconuts. Mite diversity was the highest in the state Para and on palms surrounded by seasonal forests and Amazonian rain-forests. Neoseiulus paspalivorus, N. baraki and P. bickleyi were identified as the most promising predators of A. guerreronis. Analyses of the influence of climatic factors revealed that dry ambient conditions favour the establishment of A. guerreronis. Neoseiulus paspalivorus and N. baraki have differing climatic requirements; the former being more abundant in warm and dry areas, the latter prevailing ill moderately tempered and humid areas. We discuss the significance of our findings for natural and biological control of A. guerreronis.

Leaching of nutrients from a sugarcane crop growing on an Ultisol in Brazil

Leaching is disadvantageous, both for economical and environmental reasons since it may decrease the ecosystem productivity and may also contribute to the contamination of surface and ground water. The objective of this paper was to quantify the loss of nitrogen and sulfur by leaching, at the depth of 0.9 m, in an Ultisol in Sao Paulo State (Brazil) with high permeability, Cultivated with sugarcane during the agricultural cycle of crop plant. The following ions were evaluated: nitrite, nitrate, ammonium, and sulfate. Calcium, magnesium, potassium, and phosphate were also evaluated at the same depth. The sugarcane was planted and fertilized in the furrows with 120 log ha(-1) of N-urea. In order to find out the fate of N-fertilizer, four microplots with (15)N-enriched fertilizer were installed. Input and output of the considered ions at the depth of 0.9 m were quantified from the flux density of water and the concentration of the elements in the soil solution at this soil depth: tensiometers, soil water retention curve and soil solution extractors were used for this quantification. The internal drainage was 205 mm of water, with a total loss of 18 kg ha(-1) of N and 10 kg ha(-1) of S. The percentage of N in the soil solution derived from the fertilizer (%NSSDF) was 1.34, resulting in only 25 g ha(-1) of N fertilizer loss by leaching during all agricultural cycle. Under the experimental conditions of this crop plant, that is, high demand of nutrients and high incorporation of crop residues, the leached N represented 15% of applied N and S leaching were not considerable; the higher amount of leached N was native nitrogen and a minor quantity from N fertilizer; and the leached amount of Ca, Mg, K and P did not exceed the applications performed in the crop by lime and fertilization. (C) 2009 Elsevier B.V. All rights reserved.

Fauna of plant-parasitic nematodes in natural and cultivated areas of the Amazon forest, Mato Grosso State, Brazil

The aim of this work was to study the diversity of the fauna of plant-parasitic nematodes in preserved areas of the Amazon forest, Mato Grosso state (MT), and to assess the effect of agricultural land use on plant-parasitic nematode communities. Soil and root samples were collected in each location in the late spring during the rainy season of 2005, in two areas of primary vegetation in Nova Maringa (Northwest) and Guaranta do Norte (North) and two adjacent areas planted with teak trees (Tectona grandis) and pasture (Brachiaria brizantha). Four-teen taxa of plant-parasitic nematodes were identified at species level: Discocriconemella degrissei, D. limitanea, Dolichodorus minor, Helicotylenchus erythrinae, H. pseudorobustus, Meloidogyne exigua, M javanica, Mesocriconema ornata, Paratrichodorus minor, Pratylenchus loosi, P zeae, Rotylenchus caudaphasmidius, Xiphinema ensiculiferum and X luci (for the first report of this in Brazil) and five at genus level (Atalodera sp., Hemicriconemoides sp., Meloidogyne sp., Paratylenchus sp., and Trophotylenchulus sp). These taxa, mainly those from primary vegetation, belong to families with different parasitic behavior, probably due to great plant diversity in the Amazon forest. Comparison between the two preserved areas revealed low index of similarity, as a consequence of the endemic flora in the Amazon forest, and no similarity was observed between preserved native vegetation and adjacent cultivated areas, demonstrating the high influence of agricultural activity on the plant-parasitic nematode communities. There is evidence of recent introduction of plant-parasitic nematodes in these cultivated areas; therefore measures should be taken to prevent the loss of economic sustainability in Amazonian soils. Keywords: abundance, Amazonia, diversity, Brachiaria brizantha, plant-parasitic nematode fauna, Tectona grandis.

Modeling soil organic carbon dynamics in Oxisols of Ibiruba (Brazil) with the Century Model

introduction of conservation practices in degraded agricultural land will generally recuperate soil quality, especially by increasing soil organic matter. This aspect of soil organic C (SOC) dynamics under distinct cropping and management systems can be conveniently analyzed with ecosystem models such as the Century Model. In this study, Century was used to simulate SOC stocks in farm fields of the Ibiruba region of north central Rio Grande do Sul state in Southern Brazil. The region, where soils are predominantly Oxisols, was originally covered with subtropical woodlands and grasslands. SOC dynamics was simulated with a general scenario developed with historical data on soil management and cropping systems beginning with the onset of agriculture in 1900. From 1993 to 2050, two contrasting scenarios based on no-tillage soil management were established: the status quo scenario, with crops and agricultural inputs as currently practiced in the region and the high biomass scenario with increased frequency of corn in the cropping system, resulting in about 80% higher biomass addition to soils. Century simulations were in close agreement with SOC stocks measured in 2005 in the Oxisols with finer texture surface horizon originally under woodlands. However, simulations in the Oxisols with loamy surface horizon under woodlands and in the grassland soils were not as accurate. SOC stock decreased from 44% to 50% in fields originally under woodland and from 20% to 27% in fields under grasslands with the introduction of intensive annual grain crops with intensive tillage and harrowing operations. The adoption of conservation practices in the 1980s led to a stabilization of SOC stocks followed by a partial recovery of native stocks. Simulations to 2050 indicate that maintaining status quo would allow SOC stocks to recover from 81% to 86% of the native stocks under woodland and from 80% to 91 % of the native stocks under grasslands. Adoption of a high biomass scenario would result in stocks from 75% to 95% of the original stocks under woodlands and from 89% to 102% in the grasslands by 2050. These simulations outcomes underline the importance of cropping system yielding higher biomass to further increase SOC content in these Oxisols. This application of the Century Model could reproduce general trends of SOC loss and recovery in the Oxisols of the Ibiruba region. Additional calibration and validation should be conducted before extensive usage of Century as a support tool for soil carbon sequestration projects in this and other regions can be recommended. (C) 2009 Elsevier B.V. All rights reserved.

Culture-Independent Assessment of Rhizobiales-Related Alphaproteobacteria and the Diversity of Methylobacterium in the Rhizosphere and Rhizoplane of Transgenic Eucalyptus

The rhizosphere is an ecosystem exploited by a variety of organisms involved in plant health and environmental sustainability. Abiotic factors influence microorganism-plant interactions, but the microbial community is also affected by expression of heterologous genes from host plants. In the present work, we assessed the community shifts of Alphaproteobacteria phylogenetically related to the Rhizobiales order (Rhizobiales-like community) in rhizoplane and rhizosphere soils of wild-type and transgenic eucalyptus. A greenhouse experiment was performed and the bacterial communities associated with two wild-type (WT17 and WT18) and four transgenic (TR-9, TR-15, TR-22, and TR-23) eucalyptus plant lines were evaluated. The culture-independent approach consisted of the quantification, by real-time polymerase chain reaction (PCR), of a targeted subset of Alphaproteobacteria and the assessment of its diversity using PCR-denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene clone libraries. Real-time quantification revealed a lesser density of the targeted community in TR-9 and TR-15 plants and diversity analysis by principal components analysis, based on PCR-DGGE, revealed differences between bacterial communities, not only between transgenic and nontransgenic plants, but also among wild-type plants. The comparison between clone libraries obtained from the transgenic plant TR-15 and wild-type WT17 revealed distinct bacterial communities associated with these plants. In addition, a culturable approach was used to quantify the Methylobacterium spp. in the samples where the identification of isolates, based on 16S rRNA gene sequences, showed similarities to the species Methylobacterium nodulans, Methylobacterium isbiliense, Methylobacterium variable, Methylobacterium fujisawaense, and Methylobacterium radiotolerans. Colonies classified into this genus were not isolated from the rhizosphere but brought in culture from rhizoplane samples, except for one line of the transgenic plants (TR-15). In general, the data suggested that, in most cases, shifts in bacterial communities due to cultivation of transgenic plants are similar to those observed when different wild-type cultivars are compared, although shifts directly correlated to transgenic plant cultivation may be found.

Biomass sustainability, availability and productivity

Research conducted on biomass for Ulcos (""Ultra-Low CO(2) Steelmaking"" European Integrated Project) has progressively focused on charcoal supply from tropical eucalyptus plantations. The sustainability of such plantations is being investigated from the viewpoint of their carbon, water and nutrient budgets: they must all be neutral or positive. Field research is producing results at the tree or stand level in several sites of Congo and Brazil, while a spatial model is developed to identify the conditions of biomass neutrality at the scale of the forest ecosystem. The productivity of biomass has been analyzed through the description of practices along the various supply-schemes that competitively feed the steel industry in Brazil and identification of bottlenecks for further expansion.

Large-scale ecological restoration of high-diversity tropical forests in SE Brazil

The complex interactions among endangered ecosystems, landowners` interests, and different models of land tenure and use, constitute an important series of challenges for those seeking to maintain and restore biodiversity and augment the flow of ecosystem services. Over the past 10 years, we have developed a data-based approach to address these challenges and to achieve medium and large-scale ecological restoration of riparian areas on private lands in the state of Sao Paulo, southeastern Brazil. Given varying motivations for ecological restoration, the location of riparian areas within landholdings, environmental zoning of different riparian areas, and best-practice restoration methods were developed for each situation. A total of 32 ongoing projects, covering 527,982 ha, were evaluated in large sugarcane farms and small mixed farms, and six different restoration techniques have been developed to help upscale the effort. Small mixed farms had higher portions of land requiring protection as riparian areas (13.3%), and lower forest cover of riparian areas (18.3%), than large sugarcane farms (10.0% and 36.9%, respectively for riparian areas and forest cover values). In both types of farms, forest fragments required some degree of restoration. Historical anthropogenic degradation has compromised forest ecosystem structure and functioning, despite their high-diversity of native tree and shrub species. Notably, land use patterns in riparian areas differed markedly. Large sugarcane farms had higher portions of riparian areas occupied by highly mechanized agriculture, abandoned fields, and anthropogenic wet fields created by siltation in water courses. In contrast, in small mixed crop farms, low or non-mechanized agriculture and pasturelands were predominant. Despite these differences, plantations of native tree species covering the entire area was by far the main restoration method needed both by large sugarcane farms (76.0%) and small mixed farms (92.4%), in view of the low resilience of target sites, reduced forest cover, and high fragmentation, all of which limit the potential for autogenic restoration. We propose that plantations should be carried out with a high-diversity of native species in order to create biologically viable restored forests, and to assist long-term biodiversity persistence at the landscape scale. Finally, we propose strategies to integrate the political, socio-economic and methodological aspects needed to upscale restoration efforts in tropical forest regions throughout Latin America and elsewhere. (C) 2010 Elsevier BA/. All rights reserved.

Production of finger millet (Eleusine coracana (L.) Gaertn.) dry matter under anticipated fertilization of soybeans

Due to the lack of information about the effects of soybean fertilization anticipation and the use of Eleusine coracana (L.) Gaerm. (ANSB Pe-de-galinha 5352) as cover culture, and the need for new techniques for the management of the agro-ecosystem in a more conservationist, sustainable and functional manner the goal of this research was to study the effects of anticipated fertilization on the production of dry matter in E. coracana. The experiments were carried out in an Oxisol, during the growing seasons of 200112002, 200212003 and 200312004, in Piracicaba, SP Brazil (22`50`25""S and 48`01`65""W). The experimental design was of totally randomized blocks and twelve treatments (lev- els of anticipated fertilization) were used with three repetitions. The base fertilization of soybean culture was partially anticipated, in the sowing for the finger-millet crop. Approximately 70 days after sowing, samples of the finger millet plants were collected in order to evaluate the dry matter production and to desiccate them thereafter It is concluded that the anticipation of phosphorus and potassium fertilization of soybean increases the dry matter production of E. coracana; in addition, E. coracana holds a great potential for the production of plant residues and it can be used in culture rotation or in no-tillage production systems.

qNMR: An applicable method for the determination of dimethyltryptamine in ayahuasca, a psychoactive plant preparation

Ayahuasca is an Amazonian plant beverage obtained by infusing the pounded stems of Banisteriopsis caapi in combination with the leaves of Psychotria viridis. P. viridis contains the psychedelic indole N,N-dimethyltryptamine (DMT). This association has a wide range of use in religious rituals around the world. In the present work, an easy, fast and non-destructive method by Nuclear Magnetic Resonance of proton ((1)H NMR) for quantification of DMT in ayahuasca samples was developed and validated. 2,5-Dimethoxybenzaldehyde (DMBO) was used as internal standard (IS). For this purpose, the area ratios produced by protons of DMT (N(CH(3))(2)) at 2.70 ppm, singlet, (6H) and for DMBO (Ar(OCH(3))(2)) at 3.80 and 3.89 ppm, doublet, (6H) were used for quantification. The lower limit of quantification (LLOQ) was 12.5 mu g/mL and a good intra-assay precision was also obtained (relative standard deviation < 5.1%). The present (1)H NMR method is not time consuming and can be readily applied to monitor this tryptamine in plant preparations. We believe that qNMR can be used for identification and quantification of many plant-based products and metabolites with important advantages, while comparing with other analytical techniques. (C) 2010 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved.

Mercury exposure and oxidative stress in communities of the Brazilian Amazon

This study was designed to assess possible associations between biomarkers of mercury (Hg) exposure and oxidative stress in fish-eating Amazonian communities. Clinical samples were obtained from riparians living in the Brazilian Amazon. Biomarkers of oxidative stress (glutathione - GSH, glutathione peroxidase - GSH-Px, catalase - CAT, activity and reactivation index of delta-aminolevulinate dehydratase - ALA-D (R%) were determined in blood. Total Hg was measured in whole blood (B-Hg), plasma (P-Hg) and hair (H-Hg). Association between biomarkers of Hg exposure and oxidative stress were examined using multiple regression models, including age, gender, alcohol consumption, smoking status, fish consumption and then stratified for gender. Significant inverse relations were observed between GSH-Px, GSH, CAT, ALA-D activity and B-Hg or H-Hg (p<0.05). ALA-D reactivation index was positively related to B-Hg (p<0.0001). P-Hg was directly related to ALA-D reactivation index and inversely associated with GSH-Px, GSH, and ALA-D activity (p<0.05). When stratified for gender, women showed significant inverse associations between all biomarkers of Hg exposure and CAT (p<0.05) or GSH (p<0.05), while for men only P-Hg showed a significant inverse relation with GSH (p<0.001). Our results clearly demonstrated an association between Hg exposure and oxidative stress. Moreover, for B-Hg, P-Hg and H-Hg gender differences were present. (C) 2009 Elsevier B.V. All rights reserved.

Accelerated Stability and Moisturizing Capacity of Emulsions Presenting Lamellar Gel Phase Obtained from Brazilian Natural Raw Material

Oil-in-water (O/W) emulsions containing gel phase were developed with cupuassu and/or cocoa butter from Brazilian ecosystem. They were subjected to storage advanced stability tests (SAST) and to in vivo corneometry evaluation. The evaluated emulsions showed great performance in the evaluated conditions considering that no significant variation was observed. The moisturizing potential was advantageous even without the moisturizing active. The formulation was considered a good cosmetic moisturizing cream and a promise as a drug carrier.

Evaluation of the genotoxic and antigenotoxic effects after acute and subacute treatments with acai pulp (Euterpe oleracea Mart.) on mice using the erythrocytes micronucleus test and the comet assay

Acai, the fruit of a palm native to the Amazonian basin, is widely distributed in northern South America, where it has considerable economic importance. Whereas individual polyphenolics compounds in Acai have been extensively evaluated, studies of the intact fruit and its biological properties are lacking. Therefore, the present study was undertaken to investigate the in vivo genotoxicity of Acai and its possible antigenotoxicity on doxorubicin (DXR)-induced DNA damage. The Acai pulp doses selected were 3.33, 10.0 and 16.67 g/kg b.w. administered by gavage alone or prior to DXR (16 mg/kg b.w.) administered by intraperitoneal injection. Swiss albino mice were distributed in eight groups for acute treatment with acai pulp (24 h) and eight groups for subacute treatment (daily for 14 consecutive days) before euthanasia. The negative control groups were treated in a similar way. The results of chemical analysis suggested the presence of carotenoids, anthocyanins, phenolic. and flavonoids in Acai pulp. The endpoints analyzed were micronucleus induction in bone marrow and peripheral blood cells polychromatic erythrocytes, and DNA damage in peripheral blood, liver and kidney cells assessed using the alkaline (pH > 13) comet assay. There were no statistically significant differences (p > 0.05) between the negative control and the groups treated with the three doses of Acai pulp alone in all endpoints analyzed, demonstrating the absence of genotoxic effects. The protective effects of Acai pulp were observed in both acute and subacute treatments, when administered prior to DXR. In general, subacute treatment provided greater efficiency in protecting against DXR-induced DNA damage in liver and kidney cells. These protective effects can be explained as the result of the phytochemicals present in Acai pulp. These results will be applied to the developmental of food with functional characteristics, as well as to explore the characteristics of Acai as a health promoter. (C) 2009 Elsevier B.V. All rights reserved.