Abstract
Regulation of resource allocation in plants is the key to integrate understanding of metabolism and resource flux across the whole plant. The challenge is to understand trade-offs as plants ...balance allocation between different and conflicting demands, e.g., for staying competitive with neighbours and ensuring defence against parasites. Related hypothesis evaluation can, however, produce equivocal results. Overcoming deficits in understanding underlying mechanisms is achieved through integrated experimentation and modelling the various spatio-temporal scaling levels, from genetic control and cell metabolism towards resource flux at the stand level. An integrated, interdisciplinary research concept on herbaceous and woody plants and its outcome to date are used, while drawing attention to currently available knowledge. This assessment is based on resource allocation as driven through plant-pathogen and plant-mycorrhizosphere interaction, as well as competition with neighbouring plants in stands, conceiving such biotic interactions as a “unity” in the control of allocation. Biotic interaction may diminish or foster effects of abiotic stress on allocation, as changes in allocation do not necessarily result from metabolic re-adjustment but may obey allometric rules during ontogeny. Focus is required on host-pathogen interaction under variable resource supply and disturbance, including effects of competition and mycorrhization. Cost/benefit relationships in balancing resource investments versus gains turned out to be fundamental in quantifying competitiveness when related to the space, which is subject to competitive resource exploitation. A space-related view of defence as a form of prevention of decline in competitiveness may promote conversion of resource turnover across the different kinds of biotic interaction, given their capacity in jointly controlling whole plant resource allocation.
Agricultural practices contribute to emissions of the greenhouse gases CO
2, CH
4 and N
2O. The aim of this study was to determine and discuss the aggregate greenhouse gas emission (CO
2, CH
4 and N
...2O) from two different farming systems in southern Germany. Farm A consisted of 30.4
ha fields (mean fertilization rate 188
kg N per ha), 1.8
ha meadows, 12.4
ha set-aside land and 28.6 adult beef steers (year-round indoor stock keeping). Farm B followed the principles of organic farming (neither synthetic fertilizers nor pesticides were used) and it consisted of 31.3
ha fields, 7
ha meadows, 18.2
ha pasture, 5.5
ha set-aside land and a herd of 35.6 adult cattle (grazing period 6 months). The integrated assessment of greenhouse gas emissions included those from fields, pasture, cattle, cattle waste management, fertilizer production and consumption of fossil fuels. Soil N
2O emissions were estimated from 25 year-round measurements on differently managed fields. Expressed per hectare farm area, the aggregate emission of greenhouse gases was 4.2 and 3.0
Mg CO
2 equivalents for farms A and B, respectively. Nitrous oxide emissions (mainly from soils) contributed the major part (about 60%) of total greenhouse gas emissions in both farming systems. Methane emissions (mainly from cattle and cattle waste management) were approximately 25% and CO
2 emissions were lowest (circa 15%). Mean emissions related to crop production (emissions from fields, fertilizer production, and the consumption of fossil fuels for field management and drying of crops) was 4.4 and 3.2
Mg CO
2 equivalents per hectare field area for farms A and B, respectively. On average, 2.53% of total N input by synthetic N fertilizers, organic fertilizers and crop residues were emitted as N
2O–N. Total annual emissions per cattle unit (live weight of 500
kg) from enteric fermentation and storage of cattle waste were about 25% higher for farm A (1.6
Mg CO
2 equivalents) than farm B (1.3
Mg CO
2 equivalents). Taken together, these results indicated that conversion from conventional to organic farming led to reduced emissions per hectare, but yield-related emissions were not reduced.
This study describes an integrated approach (1) to monitor the quantity and quality of water extractable organic matter (WEOM) and size, structure and function of microbial communities in space ...(depth) and time, and (2) to explore the relationships among the measured properties. The study site was an arable field in Southern Germany under integrated farming management including reduced tillage. Samples of this Eutric Cambisol soil were taken in July 2001, October 2001, April 2002 and July 2002 and separated into three depths according to the soil profile (0–10
cm, 10–28
cm and 28–40
cm). For each sample, the quantity and quality (humification index, HIX) of water extractable organic matter (WEOM) were measured concomitantly with soil enzyme activities (alkaline phosphatase, β-glucosidase, protease) and microbial community size (
C
mic). Furthermore, microbial community structure was characterised based on the fingerprints of nucleic acids (DNA) as well as phospholipid fatty acids (PLFA). We observed strong influences of sampling date and depth on the measured parameters, with depth accounting for more of the observed variability than date. Increasing depth resulted in decreases in all parameters, while seasonal effects differed among variants. Principal component (PC) analysis revealed that both DNA and PLFA fingerprints differentiated among microbial communities from different depths, and to a smaller extent, sampling dates. The majority of the 10 PLFAs contributing most to PC 1 were specific for anaerobes. Enzyme activities were strongly related to
C
mic, which was depending on water extractable organic carbon and nitrogen (WEOC and WEON) but not to HIX. HIX and WEOM interact with the microbial community, illustrated by (1) the correlation with the number of PLFA peaks (community richness), and (2) the correlations with community PC analysis scores.
We describe an efficient Er:YAG laser that is resonantly pumped using continuous-wave (CW) laser diodes at 1470 nm. For CW lasing, it emits 6.1 W at 1645 nm with a slope efficiency of 36%, the ...highest efficiency reported for an Er:YAG laser that is pumped in this manner. In Q-switched operation, the laser produces diffraction-limited pulses with an average power of 2.5 W at 2 kHz PRF. To our knowledge this is the first Q-switched Er:YAG laser resonantly pumped by CW laser diodes.
Zusammenfassung
Hintergrund und Ziel
In den letzten Jahren hat Palmöl als Bioenergieträger immer mehr an Bedeutung gewonnen, da es aufgrund seines hohen Flächenertrags äußerst kostengünstig ...produziert werden kann. Gleichzeitig gerät Palmöl vermehrt in die Kritik, weil neue Studien die ökologisch nachteiligen Folgen des Anbaus höher einschätzen als ursprünglich vermutet. Aufgrund der großen Nachfrage nach Palmöl werden die ökologisch verträglichen Anbauflächen zunehmend knapp. Daher wird Naturwald gerodet, um neue Plantagen anzulegen, was zu einem Verlust an Biodiversität und zur Emission von Treibhausgasen führt. Mithilfe einer Ökobilanz können die gesamten Umweltauswirkungen, die sich bei der Produktion und Nutzung von Palmöl ergeben, erfasst werden. Ein Teilaspekt der Ökobilanz ist die Treibhausgasbilanz, die aufgrund des Klimawandels zurzeit besonders gründlich betrachtet wird. Bei Palmöl ließe sich diese Treibhausgasbilanz entscheidend verbessern, wenn die Palmölgewinnung optimiert würde. Das Ziel des Artikels ist es daher, die Optimierungspotenziale für Palmöl hinsichtlich Ressourcenschonung und Klimaschutz im Einzelnen darzustellen.
Ergebnisse und Diskussion
Sowohl bei bestehenden Plantagen als auch bei Neuanlagen können enorme Mengen an Treibhausgasen gegenüber heute eingespart werden, indem zum einen die Plantagen effektiver betrieben und die anfallenden Reststoffe vollständig genutzt werden, und zum anderen eine Neuanlage von Plantagen auf Brachflächen erfolgt, anstatt Regenwald zu roden oder andere Plantagen umzuwidmen. Die Ergebnisse zeigen, dass das Gesamtpotenzial zur Optimierung hoch ist. Zum einen erhält man eine bessere Treibhausgasbilanz, wenn das Plantagenmanagement effizienter gestaltet wird. Zum anderen können große Mengen an Reststoffen, die bei der Palmölherstellung anfallen, genutzt werden. Vor allem die Fasern und Schalen der Ölpalmenfrüchte sowie die Nutzung des bei der Aufbereitung der Ölmühlenabwässer entstehenden Biogases können zur Stromerzeugung verwendet werden und so die Ökobilanz entscheidend verbessern. Bei optimierter Bewirtschaftung lassen sich auf bestehenden Plantagen jährlich etwa 4,8 t an Treibhausgasen pro Hektar und Jahr auf der Basis von CO
2
-Äquivalenten einsparen, was sich vor allem auf die Reduktion von Methan aus den Ölmühlenabwässern zurückführen lässt. Emissionen werden ebenfalls entscheidend gesenkt, wenn neue Plantagen auf vorhandenen Brachflächen anstelle von Naturwaldflächen angelegt werden. Damit ist eine weitere Einsparung von 4,8 t CO
2
-Äquivalenten pro Hektar und Jahr möglich. Die Errichtung einer Plantage auf Brachflächen ist zwar kostenintensiver als die Errichtung auf Naturwaldflächen, trägt aber nicht nur zu einer positiveren Treibhausgasbilanz von Palmöl, sondern auch zum Schutz der Biodiversität bei. Nutzt man also das gesamte Potenzial vollständig aus, so lassen sich jährlich 10,2 t mehr an CO
2
-Äquivalenten pro Hektar einsparen als bei der heute üblichen Produktion und Nutzung von Palmöl.
Schlussfolgerungen und Ausblick
Da die ökologisch verträglichen Anbauflächen aufgrund der großen Nachfrage nach Palmöl auf dem Weltmarkt zunehmend knapp werden, ist eine Optimierung der bislang ungenutzten Potenziale aus ökologischer, aber auch aus ökonomischer Sicht unbedingt erstrebenswert. So sollte auf das Errichten von Neuplantagen auf Naturwaldflächen zugunsten einer Anlage auf Brachflächen verzichtet werden. Zudem sollte das Plantagenmanagement optimiert und ein effizientes Konzept zur Reststoffverwertung und Abwasserbehandlung erstellt werden. Eine wichtige Voraussetzung für eine nachhaltige Palmölproduktion ist, die vorhandenen Optimierungspotenziale auch auszuschöpfen. Da dies aufgrund hoher Anfangsinvestitionskosten zur Zeit nicht geschieht, ist es ratsam, entsprechende Maßnahmen zur Realisierung der genannten Optimierungspotenziale zu ergreifen, so z. B. möglichst rasch ein international gültiges Zertifizierungssystem zu verabschieden und damit Anreize zu bieten, ökologisch verbessert zu produzieren.
Data on the dynamics of dissolved or water extractable organic matter (DOM, WEOM) in soils are often contradicting, which is especially true for arable soils. Since a complex set of soil inherent and ...environmental factors affects these dynamics, there is still a great need for additional data. Especially DOM results from (arable) field studies and long-term trials are scarce. We sampled the WEOM of the soils under three fertilization treatments in a Haplic Chernozem differing in fertilization intensity for over 90 years: (i) no fertilization (Control), (ii) mineral fertilization (NPK), and (iii) mineral plus additional farmyard manure fertilization (NPK
+
FYM). We sampled the WEOM from 0–40 cm at 10 cm intervals over a three year period during three seasons (spring, summer, and fall). We measured WEOM quantity (WEOC and WEON concentrations) and investigated the quality of WEOM with UV (absorptivity) and fluorescence (humification index, HIX) as well as biodegradability (BWEOC). The total soil organic carbon (SOC) and nitrogen (TN) were also quantified. The overall results indicated that NPK did not affect SOC and TN but did increase WEOC and WEON even though NPK does not contain organic matter, implying that fertilization affected WEOM via the biomass. The more aromatic and condensed compound of WEOM were especially increased. The NPK
+
FYM treatment also increased SOC and TN and had a stronger effect on WEOM than NPK alone. However, BWEOC was not significantly affected by fertilization practices. The three sampled years varied strongly in total precipitation and in crop type. Nevertheless, with the exception of WEON and HIX, no significant overall annual fluctuations could be detected. A seasonal pattern was found in WEOM concentration and quality but, except for WEON and HIX, fertilization treatments did not influence this seasonal pattern. The effects of fertilization did not vary as a function of depth for the parameters WEOC, WEON, and BWEOC, presumably because of their mobile nature. For the immobile SOC and TN depth had an effect. The values in the plough layer (0–30 cm) were significantly higher than in the region below it (30–40 cm). Absorptivity and HIX also showed such a pattern, indicating that more aromatic and condensed compounds are either preferentially retained or not as well metabolized in the plough layer.
Inhibitors of viral cell entry based on poly(styrene sulfonate) and its core–shell nanoformulations based on gold nanoparticles are investigated against a panel of viruses, including clinical ...isolates of SARS‐CoV‐2. Macromolecular inhibitors are shown to exhibit the highly sought‐after broad‐spectrum antiviral activity, which covers most analyzed enveloped viruses and all of the variants of concern for SARS‐CoV‐2 tested. The inhibitory activity is quantified in vitro in appropriate cell culture models and for respiratory viral pathogens (respiratory syncytial virus and SARS‐CoV‐2) in mice. Results of this study comprise a significant step along the translational path of macromolecular inhibitors of virus cell entry, specifically against enveloped respiratory viruses.
Macromolecules are shown herein to act as broadly acting antiviral agents, most importantly against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), by interacting with the viruses thereby inhibiting viral entry. Antiviral activity is demonstrated in vitro against a panel of viruses, and in vivo against two respiratory pathogens (respiratory syncytial virus (RSV) and SARS‐CoV‐2). With due optimization, polymers hold translational promise as first‐line broad‐spectrum antivirals.
Molecular techniques were used to characterize bacterial community structure, diversity (16S rDNA), and activity (16S rRNA) in rhizospheres of three grain legumes: faba beans (Vicia faba L., cv. ...Scirocco), peas (Pisum sativum L., cv. Duel) and white lupin (Lupinus albus L., cv. Amiga). All plants were grown in the same soil under controlled conditions in a greenhouse and sampled after fruiting. Amplified 16S rDNA and rRNA products (using universal bacterial primers) were resolved by denaturing gradient gel electrophoresis (DGGE). Distinct profiles were observed for the three legumes with most of the bands derived from RNA being a subset of those derived from DNA. Comparing the total bacterial profiles with actinomycete-specific ones (using actinomycete-specific primers) highlighted the dominance of this group in the three rhizospheres. 16S PCR and RT-PCR products were cloned to construct libraries and 100 clones from each library were sequenced. Actinomycetes and proteobacteria dominated the clone libraries with differences in the groups of proteobacteria. Absence of β-subdivision members in pea and γ-subdivision members of proteobacteria in faba bean rhizosphere was observed. Plant-dependent rhizosphere effects were evident from significant differences in the bacterial community structure of the legume rhizospheres under study. The study gives a detailed picture of both residing and "active" bacterial community in the three rhizospheres. The high abundance of actinomycetes in the rhizospheres of mature legumes indicates their possible role in soil enrichment after the legumes are plowed into the soil as biofertilizers.
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