Search

Miscanthus giant is one of the perspective crops for the soil and climatic zone of Ukraine, which is grown as raw material for processing into solid biofuels. However, for industrial use there is no cultivation technology adapted to the conditions of Ukraine. One of the promising directions is to study the conditions of giant miscanthus productivity increasing on the basis of determining the features of plant growth and development, improving the elements of cultivation technology in the conditions of the Western Forest Steppe. As a result of the observations and calculations, the peculiarities of plant growth and development in the first and subsequent years of vegetation and the formation of the above ground mass (biomass) of giant miscanthus were analyzed, depending on the soil and climatic conditions of cultivation. The regularities of growth conditions dependens, development and formation of miscanthus productivity due to influence of agrotechnical factors of planting density and mass of rhizomes are established in the study. Biometric indices of giant miscanthus plants in sprout height for October make a maximum value of 159 cm for planting density of 15 thousand plants / ha with mass of rhizomes 41-70 g. The maximum value of the biomass yield indicator was noted for planting density study of 15,000 units / ha with rhizomes of 41-70 g, which averaged 18.5 tons / ha during the years of analysis. Based on the results of the research, for providing a high productivity of miscanthus giant plants as raw material for Western Forest-Steppe biofuel production, the planting density of 15 thousand plants / ha with rhizomes 41-70 g is recommended. Improved technology for the cultivation of giant miscanthus for biofuel production is proposed

Apparent electrical conductivity is an important parameter for describing the spatial variability of physical and chemical attributes of the soil and for the delineation of management zones. The objective of this work is to outline management zones for the cocoa cultivation based on the spatial variability of the productivity and the apparent electrical conductivity (ECa) of the soil. Data collection was performed in a regular sample grid containing 120 points in an area cultivated with cocoa trees, located in the municipality of Ilheus, state of Bahia, Brazil. At each sampling point (cocoa tree), soil samples were collected to determine chemical attributes. Productivity was measured for one year, counting, monthly, the number of fruits, which were classified into off-season cocoa, harvest and annual production. Measurements of the apparent electrical conductivity of the soil were performed at different times of the year using a portable conductivity meter. The data were analyzed using classical statistics and geostatistics. The management zones were delineated using the fuzzy k-means algorithm. The ideal number of class was defined using the fuzziness performance index (FPI) and the entropy of the modified partition (MPE) indexes. The Kappa coefficient was used to validate the management zones, assessing their agreement with the chemical attributes of the soil. The ECa of the soil values presented moderate temporal variation, with maximum amplitude of 19.37 mS m−1 and minimum of 0.82 mS m−1 between measurement periods; higher averages of the ECa coincided with the highest levels of water in the soil. The measurements of the ECa of the soil carried out in April and October showed greater correlation with the chemical attributes of the soil, with significant values for 11 and 8 of the 17 attributes evaluated, respectively. The management zones from the ECa measured in April showed: a) reduced number of classes; b) spatial continuity between classes, and; c) agreement from reasonable (kappa between 0.20 and 0.40) to good (kappa > 0.41) with most of the chemical attributes of the soil. The ECa of the soil measured in April is, individually, the variable recommended for the management of soil fertility in tropical areas cultivated with cocoa trees.

We have measured Cd/Ca ratios of several benthic foraminiferal species and studied benthic foraminiferal assemblages on two cores from the northern Indian Ocean (Arabian Sea and northern Bay of Bengal, BoB), in order to reconstruct variations in intermediate-water circulation and paleo-nutrient content since the last deglaciation. Intermediate water Cdw records estimated from the benthic Cd/Ca reflect past changes in surface productivity and/or intermediate–bottom-water ventilation. The benthic foraminiferal assemblages are consistent with the geochemical data. These results suggest that during the last deglaciation, Cdw variability was primarily driven by changes in intermediate-water properties, indicating an enhanced ventilation of intermediate–bottom water masses during both Heinrich Stadial 1 and the Younger Dryas (HS1 and YD, respectively). During the Holocene, however, surface primary productivity appears to have influenced Cdw more than intermediate water mass properties. This is evident during the early Holocene (from 10 to 6 cal ka) when benthic foraminiferal assemblages indicate that surface primary productivity was low, resulting in low intermediate-water Cdw at both sites. Then, from ∼ 5.2 to 2.4 cal ka, surface productivity increased markedly, causing a significant increase in the intermediate-water Cdw in the southeastern Arabian Sea and the northeastern BoB. The comparison of intermediate-water Cdw records with previous reconstructions of past Indian monsoon evolution during the Holocene suggests a direct control of intermediate-water Cdw by monsoon-induced changes in upper-water stratification and surface primary productivity.

This paper presents a quantitative study of dinoflagellate cysts (dinocysts) and palynofacies of the Campanian–Danian marly succession at the village of Tattofte (western External Rif, northwestern Morocco). The paleoenvironmental and paleoclimatic interpretations, inferred from this palynologic analysis, are compared to coeval sequences of other areas in the Northern Hemisphere. Changes in the relative abundances of dinocyst taxa, which are paleoenvironmental indicators, throughout the section suggest a deposition in a marine inner to outer neritic setting. The upper Campanian dinocyst assemblage is characterized by the presence of outer neritic-oceanic and low productivity indicator taxa (e.g., Spiniferites spp., Odontochitina spp.) and cold-water taxa (e.g., Manumiella spp., Chantangiella spp., Laciniadinium spp.), whereas, the lower Maastrichtian assemblage is characterized by inner neritic, high productivity and warm-water indicator taxa (e.g., Palaeocystodinium spp., Andalusiella spp.). The upper Maastrichtian dinocyst assemblage displays a return to an outer neritic environment under a transgressive regime, but with a cooling pulse and a moderate productivity. However, the Cretaceous–Paleogene (K/Pg) boundary interval records remarkable changes in the relative abundances of dinocyst taxa, indicating an inner neritic (coastal) setting, which is the most proximal in the study section; such changes reflect instable paleoenvironmental conditions which may be related to global cooling periods, likely caused by the Deccan volcanism in India and/or the Chicxulub asteroid impact in Mexico at the K/Pg boundary. In the Danian, the dinocyst relative abundances indicate a gradual return to stable environmental conditions. A quantitative analysis of the kerogen plots (palynomorphs, phytoclasts and amorphous organic matter (AOM)) reveals five types of palynofacies, generally indicating oxic to suboxic marine environments. The upper Campanian and upper Maastrichtian (lowermost part) strata are characterized by a playnofacies (V), indicating a distal shelf, while the lower Maastrichtian and lower Danian (uppermost part) strata record a playnofacies (III), reflecting an intermediate inner-outer neritic environment. However, the K/Pg boundary transition is characterized by playnofacies types (I) and (II), indicating a proximal (coastal) environment.

La Trobe University Faculty of Science, Technology and Engineering Murray Darling Freshwater Research CentreMDFRC item.The emergence of zooplankton from ephemeral areas upon re-wetting has been suggested as a significant contributor to billabong productivity. Sixteen experimental billabongs were designed to test two hypotheses (i) that changing the pattern of flooding alters zooplankton abundance within billabongs, and (ii) the presence of small planktivorous fish alters the zooplankton community structure and diversity within billabongs. Results indicated that flooding caused microcrustaceans to increase in abundance but not rotifers. This response was not modified by changing the time of flooding. The presence of the planktivorous fish had only a small influence on the structure of rotifer assemblages, whereas microcrustacean assemblages became dominated by juveniles. Emergence of rotifers and microcrustaceans from sediment taken from the experimental billabongs and incubated under controlled conditions indicated the existence of a large reservoir of resting stages. The number of resting stages in the sediment had not been modified by changing the season of flooding in the experimental billabongs, but it was modified by permanent inundation, which may have removed environmental cues. The presence of planktivorous fish also appeared to influence the number of resting stages that accumulated in the sediment. Emergence under stable laboratory conditions was rapid. This was not the case under more variable natural conditions.The emergence of zooplankton from ephemeral areas upon re-wetting has been suggested as a significant contributor to billabong productivity. Sixteen experimental billabongs were designed to test two hypotheses (i) that changing the pattern of flooding alters zooplankton abundance within billabongs, and (ii) the presence of small planktivorous fish alters the zooplankton community structure and diversity within billabongs. Results indicated that flooding caused microcrustaceans to increase in abundance but not rotifers. This response was not modified by changing the time of flooding. The presence of the planktivorous fish had only a small influence on the structure of rotifer assemblages, whereas microcrustacean assemblages became dominated by juveniles. Emergence of rotifers and microcrustaceans from sediment taken from the experimental billabongs and incubated under controlled conditions indicated the existence of a large reservoir of resting stages. The number of resting stages in the sediment had not been modified by changing the season of flooding in the experimental billabongs, but it was modified by permanent inundation, which may have removed environmental cues. The presence of planktivorous fish also appeared to influence the number of resting stages that accumulated in the sediment. Emergence under stable laboratory conditions was rapid. This was not the case under more variable natural conditions.

MDFRC item.1. Flow alteration has reduced connectivity between many of the world’s rivers and their floodplains,causing changes in riverine productivity and the isolation of floodplain wetlands. Environmental water is being increasingly used to help restore wetland habitats and their biota, including fish. However, some of these managed deliveries of water occur into discrete wetlands via artificial structures or at unseasonal times and may not deliver the expected gains in fish production. 2. In the Murray River, south-eastern Australia, we examined the relationship between attributes of watering and fish production (species-specific recruitment, total abundance), at two time intervals:short term (6–8 weeks after watering) and at the end of the spawning season (April) for 26 discrete watering events. The study also recognised the importance of habitat in mediating fish responses to watering and examined whether fish abundance after environmental water delivery is better predicted by attributes of watering or wetland characteristics? 3. We found that attributes of watering, including water source, its method of delivery and timing, best described fish recruitment (0+ abundance) and total fish abundance. Managers of environmental water may be able to optimise fish recruitment and abundance if they source their water from the river and deliver it during the spawning period of the target species via means that facilitate fish passage.

Scenedesmus obliquus ABC-009 is a microalgal strain that accumulates large amounts of lutein, particularly when subjected to growth-limiting conditions. Here, the performance of this strain was evaluated for the simultaneous production of lutein and biofuels under three different modes of cultivation - photoautotrophic mode using BG-11 with air or 2% CO2 and heterotrophic mode using YM medium. While it was found that the highest fatty acid methyl ester (FAME) level and lutein content per biomass (%) were achieved in BG-11 medium with CO2 and air, respectively, heterotrophic cultivation resulted in much higher biomass productivity. While the cell concentrations of the cultures grown under BG-11 and CO2 were largely similar to those grown in YM medium, the disparity in the biomass yield was largely attributed to the larger cell volume in heterotrophically cultivated cells. Post-cultivation light treatment was found to further enhance the biomass productivity in all three cases and lutein content in heterotrophic conditions. Consequently, the maximum biomass (757.14 ± 20.20 mg/L/d), FAME (92.78 ± 0.08 mg/L/d), and lutein (1.006 ± 0.23 mg/L/d) productivities were obtained under heterotrophic cultivation. Next, large-scale lutein production using microalgae was demonstrated using a 1-ton open raceway pond cultivation system and a low-cost fertilizer (Eco-Sol). The overall biomass yields were similar in both media, while slightly higher lutein content was obtained using the fertilizer owing to the higher nitrogen content of the medium.

The Bathurst caribou (Rangifer tarandus groenlandicus (Borowski, 1780)) herd declined from ∼349 000 animals in 1996 to ∼8200 in 2018. Climate-driven changes to tundra and boreal vegetation is one hypothesis for the decline. We modelled and mapped annual productivity and phenology across the herd’s range using enhanced vegetation index (EVI) data derived from a Moderate Resolution Imaging Spectroradiometer (MODIS) time series spanning 2000–2017. Maximum annual EVI, growing season length, and time-integrated EVI increased significantly on 16%, 18%, and 49% of the core annual range, respectively. Trends toward longer growing seasons were driven entirely by earlier spring green-up and, along with time-integrated EVI, were most prevalent in tundra regions. Trends in forested regions were overwhelmingly related to the influence of forest fires, which burned more than half of the range below the forest–tundra ecotone since 1965. These trends suggest that climate-driven changes in production and phenology have occurred in the tundra and forest–tundra portions of the range and could have contributed to the recent herd decline. However, the trends may also be a result of herd decline itself, given the loss of this large herbivore from the landscape. Elucidating cause and effect will require comprehensive analysis of interactions between climatic variables, herd dynamics, and vegetation change, complemented by targeted field investigations.

The agricultural soils of the Happy Valley-Goose Bay (HV-GB) region of Newfoundland and Labrador, Canada are Podzols that are converted from boreal forest and have limited productivity due to their sandy texture, acidity, low soil organic matter (SOM), cation-exchange capacity (CEC), and water and nutrient retention capacity. Although numerous studies advocate biochar for mitigating soil quality problems and enhancing agronomic productivity, there is limited information on managing biochar for boosting the productivity of Podzols under newly converted agricultural lands. A 5 year experiment evaluated the impact of eight biochar rates (0–80 Mg C·ha−1) on soil properties including SOM, CEC, and availability of plant nutrients and metals in agricultural soils of HV-GB. Both immediate and long-term impacts were thus assessed. Biochar generally improved soil fertility indicators. Although the largest rates (40 and 80 Mg C·ha−1) led to the greatest changes, significant changes were also found with rates as low as 10 Mg C·ha−1. Increasing biochar rates had diminishing returns for quality parameters of soil. The impact of biochar decreased with time after application, but the largest rate led to longer lasting effects. Although biochar was incorporated in topsoil, its effects were also measurable in the subsoil, albeit with a temporal delay, usually of 1 year. Thus, given the diminishing returns of increasing biochar rates, and that beneficial effects diminish over years, it is advisable that biochar be added in smaller amounts immediately after conversion, as little as 10 Mg C·ha−1, with regular supplementation as needed.

In Australia, the proportion of forest area that burns in a typical fire season is less than for other vegetation types. However, the 2019–2020 austral spring-summer was an exception, with over four times the previous maximum area burnt in southeast Australian temperate forests. Temperate forest fires have extensive socio-economic, human health, greenhouse gas emissions, and biodiversity impacts due to high fire intensities. A robust model that identifies driving factors of forest fires and relates impact thresholds to fire activity at regional scales would help land managers and fire-fighting agencies prepare for potentially hazardous fire in Australia. Here, we developed a machine-learning diagnostic model to quantify nonlinear relationships between monthly burnt area and biophysical factors in southeast Australian forests for 2001–2020 on a 0.25° grid based on several biophysical parameters, notably fire weather and vegetation productivity. Our model explained over 80% of the variation in the burnt area. We identified that burnt area dynamics in southeast Australian forest were primarily controlled by extreme fire weather, which mainly linked to fluctuations in the Southern Annular Mode (SAM) and Indian Ocean Dipole (IOD), with a relatively smaller contribution from the central Pacific El Nino Southern Oscillation (ENSO). Our fire diagnostic model and the non-linear relationships between burnt area and environmental covariates can provide useful guidance to decision-makers who manage preparations for an upcoming fire season, and model developers working on improved early warning systems for forest fires.

Concurrent ground-level ozone (O3) pollution and anthropogenic nitrogen (N) deposition can markedly influence dynamics and productivity in forests. Most studies evaluating the functional traits responses of rapid-turnover organs to O3 have specifically examined leaves, despite fine roots are another major source of soil carbon and nutrient input in forest ecosystems. How elevated O3 levels impact fine root biomass and biochemistry remains to be resolved. This study was to assess poplar leaf and fine root biomass and biochemistry responses to five different levels of O3 pollution, while additionally examining whether four levels of soil N supplementation were sufficient to alter the impact of O3 on these two organs. Elevated O3 resulted in a more substantial reduction in fine root biomass than leaf biomass; relative to leaves, more biochemically-resistant components were present within fine root litter, which contained high concentrations of lignin, condensed tannins, and elevated C:N and lignin: N ratios that were associated with slower rates of litter decomposition. In contrast, leaves contained more labile components, including nonstructural carbohydrates and N, as well as a higher N:P ratio. Elevated O3 significantly reduced labile components and increased biochemically-resistant components in leaves, whereas they had minimal impact on fine root biochemistry. This suggests that O3 pollution has the potential to delay leaf litter decomposition and associated nutrient cycling. N addition largely failed to affect the impact of elevated O3 levels on leaves or fine root chemistry, suggesting that soil N supplementation is not a suitable approach to combating the impact of O3 pollution on key functional traits of poplars. These results indicate that the significant differences in the responses of leaves and fine roots to O3 pollution will result in marked changes in the relative belowground roles of these two litter sources within forest ecosystems, and such changes will independently of nitrogen load.

Microalgae as source of renewable energy are very potential due to high biomass productivity and lipid content. The nutritious culture for microalgae cultivation, however, should be concerned to be affordable and feasible. Here, the utilization of peat swamp culture for microalgal cultivation was studied in comparison to the nutritious pure water. The effects of photoperiod and nitrogen sources on biomass were conducted as well. Compared to the commercial microalgae, the microalgae isolated from peat swamp showed excellent performance with the faster growth time of 10 days as well as higher biomass and its productivity of 1.72 g L−1 and 0.16 g L−1 d−1, respectively. Even for the commercial microalgae, the cultivation process using the peat swamp water led to increase in biomass by 17.2% and its productivity by 10% compared to that using the nutritious pure water. The proposed kinetic model with a modification to the modified Gompertz model showed an excellent prediction with the experimental data as R2 of 0.985 was obtained. The model could well envisage the initial biomass and lag phase compared to the original model. Hence, the model is deemed beneficial for the research development for implementation in high scale of microalgal cultivation.

A growing demand for food products from limited arable land has meant that paddy fields have been developed to provide both grain and aquatic products. China has the world's largest aquaculture area of crayfish, of which ∼86% is in the form of rice-crayfish coculture. Here, we use a life cycle assessment to evaluate and compare the environmental impacts of three farming systems: rice monoculture, crayfish monoculture, and rice-crayfish coculture. Two functional units were used: one hectare of land occupied, and one Nutrient Density Unit (NDU) – i.e., the combined nutrition delivered in rice and/or crayfish products. Rice-crayfish coculture has a larger environmental footprint than rice monoculture per hectare occupied across at least 7 of the 8 impact categories studied, though performs better than crayfish monoculture. However, rice-crayfish coculture yields 1.12 to 2.21 times more nutrition per hectare than rice monoculture and crayfish monoculture, respectively. Hence, rice-crayfish coculture was found to have lower impact per NDU across all 8 impact categories studied, compared with the monoculture systems. Application of urea, crayfish feed inputs, and electricity consumption dominated most environmental burdens for rice-crayfish coculture, while field emissions (e.g., CH4 and NH3) strongly influenced global warming potential, terrestrial acidification potential and freshwater eutrophication potential, respectively. Environmental burdens of rice-crayfish coculture could be further reduced by increasing productivity per hectare and/or improving fertilizer and feed use efficiency. Shifting from rice- and crayfish-monoculture to rice-crayfish coculture could deliver more nutrition at a lower environmental cost, as well as increasing farm profitability by 7−462%.

Microorganisms can produce bio-hydrogen (H2) during their metabolism, and especially dark fermentative production from carbohydrates is a promising option. However, the technology still suffers from low H2 production rates due to product inhibition of the H2-producing enzymes. In this study we investigate if subsurface (reservoir) microbes can be relevant bio-H2 producers and a source of high-pressure adapted enzymes. In addition, we also investigate the potential H2 productivity using an indigenous reservoir community, thereby proposing a preliminary screening workflow for mature oil fields to be used as potential in-situ H2 bioreactors. We cultured two H2-producers Marinitoga hydrogenitolerans and Thermotoga napthophila, which were isolated from high-pressure environments, and a freshly obtained oil reservoir brine containing a fermentative community under atmospheric and pressurized conditions (15–16 bar). All cultures produced H2 under atmospheric conditions with different productivities. Marinitoga shows the same cell number increase and glucose consumption under high pressure compared to atmospheric but with a significantly decreased H2 productivity of −86%. The productivity decline of the reservoir community was less pronounced with −35%. The mole fraction of H2 in the produced gas was in both cases high (0.64 and 0.82 respectively). Our results indicate strong differences in the pressure-related enzyme adaptations and may be used for screening of pressure-tolerant microbes and enzymes for enhanced bio-H2 production.

Made available in DSpace on 2022-05-01T12:09:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Top-down control by large herbivores is a well-known driver of plant diversity structure and productivity. Yet, for forest ecosystems the sign and magnitude of herbivore control across resource gradients is not well understood. We conducted a series of replicated large herbivore exclusion experiments in defaunated and non-defaunated Atlantic forests of Brazil to evaluate the effects of large herbivores on tropical plant communities. We hypothesized that the top-down impact of large herbivores on seedling recruitment, species richness, diversity and productivity would change across a natural gradient in the density of a key plant resource, the palm Euterpe edulis, which is thought to act as a foundation species. We found both positive (agonistic) and negative (antagonistic) spatially-structured effects of large herbivores on plant communities driven by an interaction between large herbivores and palm density on non-defaunated sites, but not on defaunated sites. Indeed, through its interaction with large herbivores, palm trees were able to regulate the spatial structure of seedling communities. In the non-defaunated forest, the negative impact of large herbivores on plant recruitment and species richness decreased substantially as palms became more abundant and canopy cover decreased. Furthermore, large herbivores caused a 185% increase but a 194% decrease in aboveground seedling productivity in areas of high and low palm density, respectively. In contrast, in the defaunated forest we did not find any consistent large herbivore impacts on plant recruitment or species richness across the gradient of palm density, and herbivore activity consistently had negative effects on seedling productivity. Analyses using camera trap data indicate that white-lipped peccaries (Tayassu peccari) played a key role in modulating recruitment and seedling productivity, while tapirs (Tapirus terrestris) contributed significantly to an increase in plant diversity, hence playing a functionally complementary role. Our results demonstrate that a key interaction between large forest-dwelling tropical herbivores and their palm resource results in landscape-scale modulation of plant communities through positive and negative spatially-structured feedbacks, and support the view that palms might act as foundation species in tropical forests. Anthropogenic pressures posed by defaunation and illegal palm harvesting in the Neotropics might lead to the functional loss of this interaction and the collapse of the spatial structure along palm density gradients, with cascading effects on the dynamics and productivity of tropical forests. Instituto de Biociências Departamento de Biodiversidade Universidade Estadual Paulista (UNESP), SP Department of Aquatic Ecology Netherlands Institute of Ecology, P.O. Box 50 Instituto de Ecología A.C. Red de Biología Evolutiva, Carretera Antigua a Coatepec 351, El Haya Instituto Neotropical CP 19009, PR Department of Biology University of Miami Instituto de Biociências Departamento de Biodiversidade Universidade Estadual Paulista (UNESP), SP FAPESP: 2007/03392-6 FAPESP: 2014/01986-0

Geochemical proxies—such as the isotopic compositions and abundances of redox-sensitive metals, organic biomarkers, and sedimentological indicators—can be used qualitatively and quantitatively to reconstruct marine redox landscapes through Earth history. Isotopic proxies with residence times longer than ocean mixing times, including uranium (238U/235U, commonly denoted as δ238U), are a promising but still developing approach to constrain global changes in redox conditions. Our current understanding of the controls on δ238U variability and associated isotopic fractionations is limited, complicating the interpretation of δ238U records through Earth history. With these gaps in mind, we investigate the major controls on the expression of uranium (U) isotope fractionation within two basins of the Miocene Monterey Formation (ca. 18–6 Ma) that represent contemporaneous deposition under different environmental conditions. Our finding that the isotopic offset in the productive and anoxic Santa Barbara Basin is similar to that in modern euxinic settings suggests that highly productive settings without persistent euxinia can also exert significant leverage on seawater δ238U. Distinct patterns in U concentrations and δ238U between basins demonstrate that local depositional controls can impart a strong influence on the U isotope offset in reducing settings, as has been observed in modern sediment datasets. High productivity and low sedimentation rates are predicted to result in a diagnostic inverse relationship between U enrichment and δ238U, which can partially explain the overall weak negative correlation between [U] and δ238U in the distal Naples Beach section in the Santa Barbara Basin. In a core from a more restricted proximal setting in the San Joaquin Basin, we propose that changes in basin hydrography led to a potential relationship between [U] and δ238U. These interpretations are consistent with the characteristic depositional conditions interpreted independently for each basin (e.g., persistence of anoxia, productivity, sedimentation rates, phosphate content, and basin hydrography) and are supported by modeling results of U enrichment and isotope fractionation under these conditions. In particular, our results suggest that the isotope offset of U in reducing sinks varies and has done so over Earth history and in different paleogeographic locations as a result of local productivity and basin restriction. These variations indicate the need to consider these uncertainties in quantitative models of global redox conditions from δ238U records—and specifically in using δ238U to distinguish between euxinic and oxic redox states without considering other oxygen-depleted environments as part of a continuum of settings that can impact δ238U if spatially widespread. This study also highlights the utility of using different lithologies to evaluate global versus local controls on δ238U records as well as multi-proxy approaches to constrain ancient redox landscapes.

Fertilization of hybrid poplar (HP) plantations with papermill by-products is a promising solution to improve soil fertility and nutrient availability, increase plantation productivity, and provide added value to these materials that would otherwise be incinerated or sent to the landfill. We assessed the growth and foliar nutrition of a HP clone (Populus ×canadensis × Populus maximowiczii) at six plantation sites aged 3–5 years in southern Quebec, Canada. Sites received a fertilization treatment consisting of a mixture of papermill biosolids (120 to 140 t·ha−1, depending on site) and lime mud (10 to 15 t·ha−1) before being planted, or no fertilization (control). Tree growth was significantly improved by fertilization, with fertilized trees showing a mean annual height increment of 1.3 m (all-site mean; SD = 0.2), compared with 0.5 m (SD = 0.4) for unfertilized trees. Foliar calcium and magnesium increased following fertilization and levels met optimal thresholds at all sites, whereas nitrogen, phosphorous, and potassium concentrations also increased, but nutritional deficiencies remained for these elements at several sites. Our results confirm the benefits of fertilizing hybrid poplars with papermill by-products, but they also indicate that adjustments in application rates or type of by-products could be made to fully satisfy nutritional requirements and thus optimize tree growth.

To investigate the influence of three population densities (88,000, 44,000, and 29,000 plants/ha) on the growth and yield of five cowpea varieties (IT97K-461, IT97K-568-18, IT98K-131-2, IT99K-1060 and IT99K-`245), a field experiment was conducted at Teaching and Research farm of Landmark University. Growth parameters such as germination count, plant height, and number of trifoliate leaves per plant, number of branches per plant, flower production dynamics and dry matter determination were measured, while harvest index, shelling percentage, number of seeds per pod, see weight pods per plant and grain yield were measured at harvest as yield components. Data were subjected to statistical analysis of variance (ANOVA) using SAS Institute. Significant means were separated using Duncans Multiple Range Test at 5% probability level. Results revealed that there were no constant trends in growth parameters response to population density. Plant height and flower production decreased with increased population density, while number of leaves per plant and dry matter increased with increasing population density. There was no appreciable effect of population density on branching. All these parameters were significantly (p≤0.05) affected with variety, while there was no significant (p≤0.05) interaction effect. Most yield components decreased with increasing population density while grain yield however, slightly increased with increasing population density. All yield parameter and grain yield significantly varied with variety, while there were no appreciable interaction effect. In conclusion, a population density of 88,000 plants /ha gives the highest growth and grain yield. While, variety, IT97-568-18 gives the higher growth and grain yield than other varieties studied.

The recent advancement in LED technology led many incubator manufacturers and research labs to switch to these more efficient, yet spectrally restricted, light sources. Potential effects of commercially available broad range “white” light systems on phytoplankton growth, productivity, light absorption spectra, and cellular composition have not yet been characterized but could affect our interpretation of lab-based projections on responses to environmental changes. In this study, we investigated such effects using cultures of Prochlorococcus marinus, Synechococcus sp., and Thalassiosira weissflogii grown under three different commercially available LED lights as well as one fluorescent growth light. Photosynthetically active radiation was equal for each species, while photosynthetically usable radiation differed among the combinations of species and treatments. Growth rate was unaffected across species, yet all species displayed changes in cellular carbon, nitrogen, and chlorophyll a quotas as a direct response to the different light spectra. 14C-based primary productivity was also affected in P. marinus and T. weissflogii. Analysis of pigment ratios and photophysiological data indicated changes in the photoacclimation state between different light environments. The results of this study show that these species undergo changes in underlying cellular metabolism which in turn affect cellular composition while keeping specific growth constant. The data presented here illustrate ecophysiological responses of differently pigmented species when grown under different artificial growth light spectra. These cellular acclimation responses should be considered when designing laboratory-based incubation experiments, especially when comparing responses to specific changes in environmental conditions, or when implementing physiological parameters, derived from laboratory experiments, into numerical models.

The blue swimmer crab (BSC, Portunus armatus) is an economically and culturally important species distributed throughout the coastal waters of the Indo-Pacific region. Reproduction of BSC is poorly understood in south-eastern Australia, a region that is experiencing substantial tropicalisation from global warming. We examined gonadal development, egg–mass relationships, and the influence of temperature on gonadal development and egg production within five different estuaries spanning ~2.5° of latitude. A negative correlation between the gonadosomatic index (GSI, an index of gonadal development and reproductive investment) and hepatosomatic index (HSI, an index of energy storage) was observed in only the final stages of ovarian development. The weight of the egg mass increased logarithmically with body mass, accounting for up to 55% of total body mass, which was significantly larger than observed in other studies. Thermal performance curves showed a peak in individual reproductive output at a mean monthly temperature of ~24°C, at which the individual egg mass weight reached a maximum and the HSI reached a minimum. Environmentally driven variation in BSC reproduction has implications for population productivity and inter-annual variation in recruitment.

Microalgae biomass is considered an important feedstock for biofuels and other bioactive compounds due to its faster growth rate, high biomass production and high biomolecules accumulation over first and second-generation feedstock. This research aimed to maximize the specific growth rate of fresh water green microalgae Closteriopsis acicularis, a member of family Chlorellaceae under the effect of pH and phosphate concentration to attain enhanced biomass productivity. This study investigates the individual and cumulative effect of phosphate concentration and pH on specific growth characteristics of Closteriopsis acicularis in autotrophic mode of cultivation for bioethanol production. Central-Composite Design (CCD) strategy and Response Surface Methodology (RSM) was used for the optimization of microalga growth and ethanol production under laboratory conditions. The results showed that high specific growth rate and biomass productivity of 0.342 day−1 and 0.497 g L−1 day−1 respectively, were achieved at high concentration of phosphate (0.115 g L−1) and pH (9) at 21st day of cultivation. The elemental composition of optimized biomass has shown enhanced elemental accumulation of certain macro (C, O, P) and micronutrients (Na, Mg, Al, K, Ca and Fe) except for nitrogen and sulfur. The Fourier transform infrared spectroscopic analysis has revealed spectral peaks and high absorbance in spectral range of carbohydrates, lipids and proteins, in optimized biomass. The carbohydrates content of optimized biomass was observed as 58%, with 29.3 g L−1 of fermentable sugars after acid catalyzed saccharification. The bioethanol yield was estimated as 51 % g ethanol/g glucose with maximum of 14.9 g/L of bioethanol production. In conclusion, it can be inferred that high specific growth rate and biomass productivity can be achieved by varying levels of phosphate concentration and pH during cultivation of Closteriopsis acicularis for improved yield of microbial growth, biomass and bioethanol production.

In this study, we present the assimilation of data from the Orbiting Carbon Observatory-2 (OCO-2) (land nadir and glint data, version 9) to estimate the Australian carbon surface fluxes for the year 2015. To perform this estimation, we used both a regional-scale atmospheric transport–dispersion model and a four-dimensional variational assimilation scheme. Our results suggest that Australia was a carbon sink of −0.41 ± 0.08 PgC yr−1 compared to the prior estimate 0.09 ± 0.20 PgC yr−1 (excluding fossil fuel emissions). Most of the carbon uptake occurred in northern Australia over the savanna ecotype and in the western region over areas with sparse vegetation. Analysis of the enhanced vegetation index (EVI) suggests that the majority of the carbon uptake over the savanna ecosystem was due to an increase of vegetation productivity (positive EVI anomalies) amplified by an anomalous increase of rainfall in summer. Further from this, a slight increase of carbon uptake in Western Australia over areas with sparse vegetation (the largest ecosystem in Australia) was noted due to increased land productivity in the area caused by positive rainfall anomalies. The stronger carbon uptake estimate in this ecosystem was partially due to the land surface model (CABLE-BIOS3) underestimating the gross primary productivity of the ecosystem. To evaluate the accuracy of our carbon flux estimates from OCO-2 retrievals, we compare our posterior concentration fields against the column-averaged carbon retrievals from the Total Carbon Column Observing Network (TCCON) and ground-based in situ monitoring sites located around our domain. The validation analysis against TCCON shows that our system is able to reduce bias mainly in the summer season. Comparison with surface in situ observations was less successful, particularly over oceanic monitoring sites that are strongly affected by oceanic fluxes and subject to less freedom by the inversion. For stations located far from the coast, the comparison with in situ data was more variable, suggesting difficulties matching the column-integrated and surface data by the inversion, most likely linked to model vertical transport. Comparison of our fluxes against the OCO-2 model intercomparison (MIP) was encouraging. The annual carbon uptake estimated by our inversion falls within the ensemble of the OCO-2 MIP global inversions and presents a similar seasonal pattern.

While many cities have embraced urban agriculture, research examining crop productivity in urban environments is limited. Little is known about how abiotic and biotic factors affecting productivity on urban farms compare with those in rural environments. In this study, we investigated environmental factors influencing strawberry (Fragaria x ananassa) productivity for two cultivars at ten farms across a rural-urban gradient in Michigan, USA over a three-year period. We evaluated key drivers of production, namely temperature, pathogens, pests, and pollinators, which we hypothesized would be altered by urbanization. We found no direct effect of urbanization on strawberry production or fruit pathogen and pest damage. However, temperature, an environmental correlate of urbanization, significantly influenced crop productivity. In particular, cooler temperatures at rural farms and warmer temperatures at urban farms limited fruit number in the peak production year. We found no relationship between urbanization and overall abundances of arthropod pests, their predators, or pollinators. However, we found opposite effects of urbanization for two arthropod groups – Vespidae (paper wasps) and Araneae (spiders). Vespidae abundance was positively associated with increased urbanization. These omnivorous wasps are both predators of strawberry pests and pests of fruits themselves. Conversely, spiders, which are predators of strawberry pests, were negatively associated with urbanization. Greater pollinator visitation incrementally improved fruit weight, but only at low to moderate levels of pathogen and pest damage. At high levels of damage, the benefits of pollination were not apparent. Our study reveals that environmental drivers of variation in crop yield, such as pathogen and herbivore damage and pollinator visitation, can be comparable across rural-urban gradients. Some factors, however, such as temperature stress and the abundances of certain pest and beneficial organisms may be affected by urbanization.

Vegetation phenology and productivity drive resource use by wildlife. Vegetation dynamics also reveal patterns of habitat disturbance and recovery. Monitoring these fine‐scale vegetation patterns over large spatiotemporal extents can be difficult, but camera traps (CTs) commonly used to survey wildlife populations also collect data on local habitat conditions. We used CTs (n = 73) from 2016 to 2019 to assess impacts of habitat change in a boreal landscape of northern Canada, where seismic lines for petroleum exploration disturbed wildlife habitat and prompted vegetation restoration efforts. First, we quantified vegetation dynamics from CTs, comparing them to satellite‐based estimates that are typically used to monitor vegetation at broad spatial scales. We then used understory phenology and productivity estimated from CT time‐lapse images to assess vegetation recovery on seismic lines. Finally, we related vegetation dynamics with the habitat use of three wildlife species: sandhill cranes Grus canadensis, woodland caribou Rangifer tarandus, and white‐tailed deer Odocoileus virginianus. CTs provided unique insight into vegetation dynamics that were different from signals measured by satellites, with temporally inconsistent and even some negative correlations between CT and satellite metrics. We found some indication of vegetation recovery on seismic lines that had received restoration treatment, with understory patterns more similar to undisturbed habitat than to seismic lines that did not receive restoration treatment. CTs also provided inferences about wildlife activity related to vegetation resources, which approaches using satellite data failed to detect. Wildlife habitat use tracked vegetation phenology, but did not always increase with vegetation productivity at weekly, 16‐day, or annual intervals. Instead, associations with vegetation productivity depended on species, temporal scale, and productivity metrics. Given the widespread and growing use of CTs to monitor terrestrial wildlife, we recommend their use to simultaneously monitor habitat conditions to better understand the mechanisms that govern wildlife habitat use in changing environments.

Fil: Trinco, Fabio D. Instituto Nacional de Tecnología Agropecuaria. Instituto de Investigaciones Forestales y Agropecuarias de Bariloche. Río Negro, Argentina. Fil: Rusch, Verónica E. Instituto Nacional de Tecnología Agropecuaria. Instituto de Investigaciones Forestales y Agropecuarias de Bariloche. Río Negro, Argentina. Fil: Howison, Ruth A. Groningen University. Groningen Institute for Evolutionary Life Sciences. Conservation Ecology Group. Países Bajos. Fil: Garibaldi, Lucas A. Universidad Nacional de Río Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. Río Negro, Argentina. Fil: Garibaldi, Lucas A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. Río Negro, Argentina. Fil: Tittonell, Pablo A. Instituto Nacional de Tecnología Agropecuaria. Instituto de Investigaciones Forestales y Agropecuarias de Bariloche. Río Negro, Argentina. Sound management of native forests used for cattle grazing requires understanding the dynamics of forage productivity in the openings. Despite their importance, forage productivity drivers in highly heterogeneous forested landscapes, or their variability over the year, are still unclear. The aim of this work is to find predictors of Normalized Difference Vegetation Index (NDVI) variation in the openings of native temperate forests and to evaluate how these predictors change within the growing season. We used high spatial resolution remote sensing imagery from NW Patagonia to separate forest openings from tree dense canopy. We obtained data of each opening related with herbaceous and shrub forage productivity and calculated landscape metrics. We estimated a multiple linear regression model for predicting NDVI in each season. Beyond known variables related with forage productivity (altitude, precipitation, etc.), the shape of forest’ openings appeared as relevant in predicting NDVI. Higher values of forest opening perimeters were related with a decrease in NDVI in spring when soil water content is not limiting and conversely with an increase in NDVI in summer when water is limiting growth. These results suggest that environmental drivers such as temperature and soil moisture inside the opening, and competition or facilitation process between trees and grasses are mediated by the shape of the opening. Management of heterogeneous native forests for cattle raising requires considering the shape of the openings to maximize forage productivity.

The impact of winter bale grazing on forage productivity and nutrient cycling was determined near Winnipeg, MB, Canada. Variable distribution of nutrients and forage yield within bale-grazed plots on a perennial grass–legume forage field was identified using an intensive grid sampling method. In bale-grazed plots, mean dry matter (DM) yield of forage decreased 68% in year 1 following bale grazing, with no difference in DM yield in year 2 following bale grazing, relative to an untreated control. Decreased yield was attributed to the large mass of waste feed and feces (21% of feed delivered) that remained at the centre of each bale-grazed plot, where each bale was placed. Concentrations of crude protein, total digestible nutrients, phosphorus (P), and potassium in forage increased in the first growing season following winter bale grazing compared with the control, particularly at the centre of each bale-grazed plot. Concentrations of residual nitrate-nitrogen and Olsen P in soil were 15 and 2.5 times greater, respectively, at the centre of the bale-grazed plots compared with untreated control plots. Dispersion of waste feed packs when bale grazing in subhumid climates on clay soils is recommended to minimize smothering and encourage rapid decomposition of waste feed and feces. Long-term studies are needed to determine the potential benefits and risks of bale grazing to forage productivity and soil nutrient status in the eastern Canadian Prairies.

Field experiments were carried out on chestnut soils of Piedmont Dagestan in 2018-2020. Hybrids of grain corn treated with different growth stimulants were the object of еру research. The experiments showed that the harvesting ripeness of hybrids ROSS 299 MV and Mashuk 355 MV occurred 2...5 days earlier after treatment with growth stimulants compared to the control. The growth stimulants used in the experiment did not have a significant effect on seed germination rate. Among the studied hybrids, the highest seed germination were observed in Mashuk 355 MV hybrid. The highest values of leaf area and net productivity of crops were in hybrid Mashuk 355 MB. Plants treated with growth regulators had higher leaf surface by 4.4% and 5.5%; 6.0 % and 8.4%, respectively. Approximately the same dynamics was recorded for photosynthesis net productivity and accumulation of dry matter. Mashuk 355 MV hybrid showed the best yield, which was 30.5; 31.5 and 32.5% higher respectively, compared to the standard. Productivity of corn hybrids treated with growth regulators increased significantly. The highest data were observed on plants treated with Megamiks N10 growth regulator, which were higher than the control data by 30.0 and 32.5%, respectively. Aminokat 30% growth regulator increased corn productivity by 23.7 and 24.7%, respectively. Sufficiently high indicators of yield structure were 10 recorded in Mashuk 355 MV hybrid in the variant with the Megamiks N10 growth stimulator.

Chronosequence studies of soil formation and ecosystem development provide important insights into the pathways and rates of change occurring on centennial and millennial time scales. In cool or temperate humid environments, Podzols are the predominant soil type formed under coniferous forests in coarse-textured parent material and have been a major focus of chronosequence studies. This study examined the rate and mechanisms of Podzol development and related forest productivity in a sand dune chronosequence in a hypermaritime climate in coastal British Columbia (BC). The sequence spans 10 760 ± 864 yr over eight sites and is the first documented chronosequence in coastal BC to span most of the Holocene Epoch. Soil samples from each genetic horizon were analyzed for bulk density, pH and concentrations of total carbon (C), pyrophosphate- and oxalate-extractable aluminum (Al) and iron (Fe), and total elements. Within ∼3500 yr, a mature Podzol had formed, with cemented horizons (ortstein and placic) present. Organo-metallic complexation appeared to be the dominant mechanism involved in podzolization. Despite a mild, moist climate conducive to chemical weathering, all soils had similarly low values for the chemical index of alteration, suggesting that congruent dissolution of primary minerals may be occurring. Ecosystem retrogression is apparent in the latter stages of the chronosequence — a phenomenon not previously documented in coastal BC. Further research is needed to examine the interactions of nutrient limitation, soil physical barriers, and other possible drivers of ecosystem retrogression.

The results of monitoring studies carried out to identify the features of the current distribution of vegetation and productivity of sandy pasture ecosystems in the south of the European territory of Russia are presented. The objects of research were natural pasture phytocenoses on the territory of the Tsimlyansk sand massif. The methods of ecological and geobotanical surveys were used in the work. Plant samples were collected at key sites located in different wet areas using the 5-fold slope method. To identify dominant and subdominant species of natural phytocenoses, the Drude species abundance assessment scale was used. It was found that the pasture ecosystems of the Tsimlyansk sand massif are characterized by the presence of 58 dominant and subdominant species from 22 families, which occupy a certain position in the herbaceous and shrub communities, depending on the moisture content of the territory. The territory of complete humidification is characterized by the presence of 7 dominants and subdominants from 7 families. In the territory of excessive moisture, 9 species from 7 families dominate in phytocenoses. On the territory of sufficient and variable moisture, 26 species from 8 families predominate in the communities. The territories of moderate humidification are distinguished by the presence in the associations of 22 dominant species from 9 families. The territory of complex moistening, which is insufficient and severely insufficient under sand hills and moderate in the groves, is characterized by the presence of 9 dominant and subdominant species from 6 families in the communities. In 2018-2020 it was revealed that the annual phytomass of the grass and grass communities of the Tsimlyansk sand massif increases from spring to summer (from 91-117 to 204-267 g/m2) and decreases from summer to autumn (from 204-267 to 156-190 g / m2). The average annual productivity of natural phytocenoses is 156-190 g / m2.

Water distillation by utilising free energy from the sun is one of the significant techniques for getting freshwater from salty and seawater. For the remote areas and small societies where freshwater is distant, solar distillation is one of the best explanations for freshwater creation. The main objective of this study is to evaluate the performance of the flat plate collector–assisted conventional solar still incorporating mirror wall and heat storage material, which was tested at Anchor institute of solar energy studies, Mehsana (23.5275311° latitude and 72.3881041° longitude), Gujarat. Moreover, the study captures average productivity with and without FPC which was 1.5 L and 1.0 L respectively during the day time for the entire period of experiments. In this study, the water depth is varied from 1 to 5 cm inside the single basin solar still to obtain the optimum depth. It was observed that when mirror augmented still was operated with the FPC, 3.6L/day productivity was achieved with 30% instantaneous efficiency, at solar radiation of 1122 W/m2 and ambient temperature of 24 °C. Also, the maximum productivity was observed at a water depth of 3 cm and 4 cm. Moreover, improvements in daily and yearly productivity were observed to be 51.515% and 56.6474% respectively, which were estimated on the basis of with and without FPC. An experiment was performed at Anchor Institute of Solar Energy, Mehsana located at the north part of Gujarat where the average annual rain was comparatively less compared to other regions, so this type of solar still can provide potable water to daily workers who work on site. Furthermore, economic study reveals 0.577 INR/litre cost of distiller output for conventional set-up and 0.477 INR/litre for the FPC assisted set-up.

Adapting crops to warmer growing season temperatures is a major challenge in mitigating the impacts of climate change on crop production. Warming temperatures drive greater evaporative demand and can directly interfere with both reproductive and vegetative physiological processes. Most of the world's crop species have C3 photosynthetic metabolism for which increasing temperature means higher rates of photorespiration, wherein the enzyme responsible for fixing CO2 fixes O2 instead followed by an energetically costly recycling pathway that spans several cell compartments. In C3 crops like wheat, rice and soybean, photorespiration translates into large yield losses that are predicted to increase as global temperature warms. Engineering less energy-intensive alternative photorespiratory pathways into crop chloroplasts drives increases in C3 biomass production under agricultural field conditions, but the efficacy of these pathways in mitigating the impact of warmer growing temperatures has not been tested. We grew tobacco plants expressing an alternative photorespiratory pathway under current and elevated temperatures (+5 °C) in agricultural field conditions. Engineered plants exhibited higher photosynthetic quantum efficiency under heated conditions than the control plants, and produced 26% (between 16% and 37%) more total biomass than WT plants under heated conditions, compared to 11% (between 5% and 17%) under ambient conditions. That is, engineered plants sustained 19% (between 11% and 21%) less yield loss under heated conditions compared to non-engineered plants. These results support the theoretical predictions of temperature impacts on photorespiratory losses and provide insight toward the optimisation strategies required to help sustain or improve C3 crop yields in a warming climate.

The results of the study of the population biology of the rare orchid Dactylorhiza incarnata (L.) Soó on the territory of the Komi Republic (north-east of European Russia), where the species is located on the northern border of its range, are presented. Data on the population structure, morphometric features of plants, and reproductive characteristics of the species are given. It was found that the size of plants and the number of flowers in the inflorescence of this species in the region is lower than in the more southern parts of its range. The populations size ranges from 30 to 350 individuals with their average density of 0.7–3.7 per 1 m2 , and it is common for this species in other parts of its distribution area. Reproductive success is associated with the weather of the second decade of June because the flowering time of the species in the region happens in this time. It was found that the seed size of D. incarnata (0.55×0.20 mm) on its northern border is smaller than in other parts of the range. The seed productivity is rather high: one fruit contains an average of 6.2 thousands of seeds and one individual could produce about 49.4 thousands of seeds. Temperature during flowering time and precipitation during seed ripening may affect seed quality. The presence of juvenile individuals (%) in all the studied populations shows seed recruitment in populations of this species at the northern limit of the range, despite a lower seed set in comparison with southern populations.

The artificial diet of Tenebrio molitor has been a focal point of many studies that aimed to design the best diet combination. Recently, studies are focusing on the use of by-products and their efficiency as diets for rearing T. molitor. The rearing was successful on a wide range of by-products-based diets. The feed has a profound impact on the lifespan, growth, productivity and nutritional composition of T. molitor. Productivity is one of the traits highly influenced by the diet’s composition, especially macronutrients. This work aims to study the effect of eight different diets on the weight and productivity of females and their progeny weight: larval weight. Wheat bran, brewer’s yeast, spent grain and bread remains were used to compose the diets, based on different inclusion percentages of each by-product. The nutritional composition, mainly the macronutrients, of the diets had a narrow range of differences. The diets were designed in a way to avoid the effect of different nutritional compositions and study the effect of the by-products type only. Results showed that the female’s weight-change during the egg-laying period was not significant under different rearing diets. Moreover, the female’s productivity measured by the larval number showed no significant difference between the different diets. However, the total larval biomass (452.4 mg) was significantly higher for larvae reared on diet A composed of wheat bran and brewer’s yeast. Also, the total mean larval weight was significantly higher for larvae reared on diets A (3.1 mg) and G (3.2 mg) composed of wheat bran, brewer’s yeast and spent grain. The mentioned diets although composed of different by-products have similar amounts of protein and carbohydrates. These results prove that the type of by-products included in the experimental diets does not affect the reproductive performance of T. molitor, while it can affect larval growth.

This study evaluated the productivity and nutrient concentrations of organic cherry tomatoes and leguminous green manures grown in intercropping systems in rotation with maize. The experimental des...

Sieving of chipped forest fuels has recently been suggested as a way to reduce dry matter losses during storage. Sieving provides a more homogeneous acceptable material with better storage properti...

Since 1990, the number of livestock in Mongolia has more than doubled. In large areas of Mongolia, grassland degradation is now a problem of national concern. A survey was done of 10 herders in two Soums (Altanbulag and Khashaat; heavily and moderately degraded, respectively) to measure the animals (sheep, goats, cattle and horse numbers, sex and weights) and grasslands (species and biomass) every 3 months from April 2017 to December 2018. Rainfall is mostly in summer and mean monthly temperatures vary from –20 to 20°C. Throughout the study, the grassland herbage mass in summer was less than 0.5 t dry matter/ha, below that considered sustainable for the steppe. Herders had 200–1000 sheep equivalents (SE, 50 kg base weight), moved camps 2–4 times each year and stocking rates varied from 0.5–1 SE/ha. Female animals reached their mature weights by 4 years of age (sheep 50 kg, goats 40 kg, cattle 350 kg, horses 300 kg). Animals only grew over summer, but a significant part of that was compensatory gain in animals >1 year old. Over winter, sheep and goats lost 21–29% of their liveweight, cattle and horses 15–30%. The weaning rate was 43–48% across species. The male:female ratio (>2 years old) was sheep 63%, goats 72%, cattle 27% and horses 106%. All animals are managed in common mobs with no particular control of breeding. Areas where the efficiency of livestock production and grassland productivity could be improved are discussed.

Beans are a cheap source of protein for human consumption and can be a source of income. Among abiotic factors, phosphorus (P) is an important element affecting bean productivity. The objectives of...

Trees within farmers’ fields can enhance systems’ longer-term productivity, for example, via nutrient amelioration, which is indispensable to attain sustainable agroecosystems. While arbuscular mycorrhizal fungi (AMF) are known to improve plant access to soil nutrients, the potential of AMF to mediate nutrient uptake of tree-derived nitrogen (N) by crops from beyond the crops’ rooting zones is unclear. We hypothesized that AMF quantitatively contribute to the crop uptake of tree-derived N. We set up root- and AMF-exclusion and control plots around faidherbia trees (Faidherbia albida) and used the 15N natural abundance technique to determine the magnitude of AMF-mediated uptake of tree-derived N by maize from beyond its rooting zone in smallholder fields. We further tested whether AMF-mediated N uptake decreases with distance from tree. We show that within one cropping season, maize obtained approximately 35 kg ha–1 biologically fixed N from faidherbia. One-third of tree-derived N in maize leaves was attributed to AMF-mediated N uptake from beyond the maize rooting zone and two-thirds to N from tree leaf litter, regardless of distance from tree. As hypothesized, maize grown close (1 m) to faidherbia obtained significantly more tree-derived N than that at farther distances (4 and 5 m). Thus, the faidherbia–AMF association can enhance agroecosystem functioning. Soil fungi can form beneficial associations with plant roots. This study finds that arbuscular mycorrhizal fungi can increase crop uptake of nitrogen derived from common trees in African smallholder maize fields, sustainably enhancing these agroecosystems.

Microalgae can accumulate a high amount of lipids under stress conditions, and, for this reason, it is of great interest in biodiesel production. To explore another promising candidate, growth, pigments, and biochemical composition of Lobochlamys sp. GUEco1006 on various growth media viz. Bold’s Basal Medium (BBM), Bristol, BG11 (Blue-green 11 medium), and Chu’s 10 were studied initially. The alga grown on BBM showed the best growth with maximum carotenoid content (4.8 µg⁄ml), lipid content (22.27%), and lipid productivity (61.5 mg L− 1d− 1). Further, the effect of salinity on pigments, lipid accumulation, and productivity of the test organism in the BBM medium was explored. The microalga attained significantly higher carotenoid content (11.13 µg⁄ml), lipid content (81.2% per dry cell weight), and lipid productivity (188.8 mg L− 1d− 1) in 0.3 M NaCl treated culture over control. This study demonstrated that salinity could act as a lipid trigger for Lobochlamys sp. GUEco1006, and it can be a promising candidate for biodiesel production in the near future.

The aim of the present study is to determine the impact of the disturbed irrigation regime on the yield and the chemical composition of Sudan grass, grown as a second crop. To accomplish this goal, a trial was conducted in the experimental field of the Agricultural Institute - Stara Zagora with Sudan grass on meadow-cinnamon soil under irrigated conditions. The following variants have been studied: 1 - without irrigation (control variant); variant 2 - optimal irrigation, 75-80% of field capacity (FC); variant 3 - irrigation as in variant 2, but with the removal of the first watering; variant 4 - irrigation as variant 2, but with the removal of the second irrigation; variant 5 - irrigation as variant 2, but with the removal of the third watering. It was found that when growing Sudan grass as a second crop with optimal irrigation and disturbed irrigation regime done by canceling successive watering, the highest yield of dry biomass is obtained with optimal irrigation including three irrigations. Its yield increased by 24.2% compared to the control treatment. Irrigation of Sudan grass with only the second and the third irrigation in a row, without the first irrigation provided, leads to the lowest yield of dry biomass - 11290 kg / ha. Among the chemical composition indicators, the most significant change is observed in the content of the crude fat, followed by that of the crude fiber and crude protein, depending on the method of growing Sudan grass (with or without irrigation).

The analysis of the influence of species and the fullness of crop rotations on the ecologization of grain production is given. The most ecologically clean crop rotation is a 2-field grain-fallow: a fallow of black winter wheat. Its productivity and efficiency are slightly inferior to crop rotations, where, in addition to winter wheat, there are spring early and late grain crops. The role of black fallow as a method of preserving moisture, accumulating nutrients, and cleaning the soil from weeds, pathogens, and pests is revealed. The role of black fallow as a method of preserving moisture, accumulating food elements, cleansing the soil from weeds, pathogens diseases and vermins is revealed. It has been established that the advantage of the fallow predecessor in increasing the productivity and technological properties of winter wheat grain in different types of crop rotations is due to the optimization of the elements of soil fertility and the phytosanitary state of agrophytocenosis. Reducing the length of rotation of grain-fallow crop rotations to two or three fields can significantly reduce weediness of crops and abandon the use of herbicides. An increase in the specific gravity weight of black fallow in crop rotations up to 25% makes it possible to increase its efficiency in clearing fields from weeds of the first two fields, reducing the volume of herbicide application by 75%. Thanks to 2, 3-field grain-fallow crop rotations, it is possible to obtain products without the use of mineral fertilizers, chemical plant protection agents, especially against weeds, thereby improving the ecological situation of the environment.

Soil physical-chemical characteristics are key factors to intraspecific variability in plant functional traits. However, little is known about how wood and leaf traits can interact to ensure similar tree growth and wood quality in sites with different edaphoclimatic conditions. Here, we investigated the effect of soil on the wood features, leaf traits, and plant growth in Eucalyptus urophylla and E. urophylla x grandis trees. We evaluated the wood features, leaf traits and tree growth in 20 six-year-old trees from the same clone of each species. We applied linear models to verify the variability in these characteristics for both clones in two trial sites. Wood with larger vessels in a lower density, higher potential hydraulic conductivity, taller and wider rays, a higher fraction of vessels and parenchyma cells and a lower fraction of fibers were observed in trees from the trial site with higher availability of water and nutrients. Moreover, the trees had lower specific leaf area and higher leaf dry matter content in this trial site. Our results show that trees studied have similar wood features that ensure safety and relative efficiency in water transport. In addition, we found different leaf traits strategies to optimize carbon uptake, thus maintaining similar productivity and wood quality in sites with different soil conditions.

Condition indices are key predictors of health and fitness in wild fish populations. Variation in body condition, therefore, can be used to identify stressful conditions that may impact endangered species, such as California’s endemic Delta Smelt (Hypomesus transpacificus McAllister, 1963). Here, we examined spatiotemporal variation in the condition indices of > 1600 Delta Smelt collected over nine years (2011–2019), a period characterized by tremendous variability in hydrodynamic and water quality conditions. The population exhibited low hepatosomatic index (HSI) and condition factor (CF) during September/October/November (fall), and both condition indices declined over the nine-year study during fall. HSI was positively correlated with indicators of pelagic productivity (e.g., Chlorophyll a, zooplankton biomass, and proximity to tidal wetlands), whereas CF was negatively correlated with temperature, peaking at a relatively cool 10–13°C. In sum, seasonal and interannual variation in body condition corresponded most strongly with pelagic productivity and water temperature, with little correlation to freshwater outflow. Management actions that increase pelagic productivity, restore and freshen productive wetlands during late summer-fall, and reduce water temperatures overall are likely to benefit condition indices and, therefore, fitness of the Delta Smelt population.

The conversion of carbohydrates in biomass via fermentation is an important component of an overall strategy to decarbonize the production of fuels and chemicals. Owing to the cost and resources required to produce biomass hydrolysates, the economic and environmental sustainability of these fermentation processes requires that they operate with high yields, sugar conversion, and productivity. Immobilized-cell technology in a continuous bioprocess can achieve significantly higher volumetric productivities than is possible from standard batch fermentation using free cells. Here, we demonstrate approaches for improvement of ethanol yield from algal hydrolysates and a mock hydrolysate medium.

This research aimed to investigate the prospected desirable influences of sowing date, planting density, and soil enrichment with humic acid (HA) on the growth and uptake of macro and micronutrients and their implications on the productivity of sunflower plants grown in dry, saline, and nutrient-deficient environment. Two field trials were conducted in two seasons (2018 and 2019) by planting the sunflower plants on two dates, one early (on May 5) and the other late (on May 30) under three planting densities of 95.2 (high), 71.4 (medium), and 57.1 (low) thousand plants ha−1 and soil enrichment with three rates of HA [0 (HA0), 24 (HA24), and 48 kg ha−1 (HA48)]. Early sowing date with soil HA48 under low planting density was the best combination for optimizing sunflower’s growth, while early sowing date with HA48 under high planting density was best for the macro and micronutrient contents of shoots and seeds, as well as seed, oil (OY), and protein yields. With the application of automatic linear modeling analysis, seed yield, oil%, stem diameter, harvest index, shoot dry weight, plant height, and seed yield plant−1 were selected as the characteristics most contributing to OY in predicting stressed sunflower’s OY. Due to the ever-climate changes, choosing an appropriate sowing date, as a non-monetary practice, and optimal planting density with adequate anti-stress (e.g., HA) substance to enrich the low-fertile saline soils is the safest effective way to maintain global food security and sustainable agricultural development in dry environments.

Fjords in Svalbard are sensitive to the enhanced climate warming-induced glacial meltwater discharge (fresher, nutrient-rich, turbid) that influences its hydrography and biological processes. This study attempts to explain the impacts of underwater light environment and nutrient limitation on the phytoplankton biomass, composition, and light absorption in the sunlit zone of the Kongsfjorden (KG)–Krossfjorden (KR) twin fjord ecosystem during summer when the meltwater discharge is at maximum. Observations conducted in two phases in each fjord revealed pronounced spatial hydrographic variations between the phases and among the fjords. Intrusion of warm Atlantic water into both fjords and occurrence of subsurface chlorophyll maxima were observed. Meltwater-induced higher concentrations of optically active constituents in KG resulted in a comparatively shallow euphotic zone than KR. Nitrate and silicate limitation (N/P 1, Si/P

The features of the distribution, formation and the cenotic dynamics of forests of Alnus barbata C.A. Mey are described; environmental functions and the role of Alnus forests in the composition of the forest cover of the region are highlighted; bioecological and forestry features are highlighted; it is indicated that Alnus barbata is an economically valuable woody species; its useful qualities for practical purposes are emphasized; the ways to increase the productivity of Alnus forests using foresting, forest melioration and forest cultural sampling, as well as measures of using valuable fast-growing, resistant to the waterlogged conditions of growing area, local and foreign woody breeds ( Cupressus lusitanica , Metasequoia glyptostroboides , Taxodium distichum , Liquidambar styraciflua, Liriodendron tulipifera, Platanus x acerifolia, Eucalyptus viminalis ).