Using either freshly pulped or preserved seaweed biomass for the extraction of protein can have a great effect on the amount of protein that can be extracted. In this study, the effect of four preservation techniques (frozen, freeze-dried, and air-dried at 40 and 70 °C) on the protein extractability, measured as Kjeldahl nitrogen, of four seaweed species, Chondrus crispus (Rhodophyceae), Ascophyllum nodosum, Saccharina latissima (both Phaeophyceae) and Ulva lactuca (Chlorophyceae), was tested and compared with extracting freshly pulped biomass. The effect of preservation is species dependent: in all four seaweed species, a differenttreatment resulted in the highest protein extractability. The pellet (i.e., the non-dissolved biomass after extraction) was also analyzed as in most cases the largest part of the initial protein ended up in the pellet and not in the supernatant. Of the four species tested, freeze-dried A. nodosum yielded the highest overall protein extractability of 59.6% with a significantly increased protein content compared with the sample before extraction. For C. crispus extracting biomass air-dried at 40 °C gave the best results with a protein extractability of 50.4%. Preservation had little effect on the protein extraction for S. latissima; only air-drying at 70 °C decreased the yield significantly. Over 70% of the initial protein ended up in the pellet for all U. lactuca extractions while increasing the protein content significantly. Extracting freshly pulped U. lactuca resulted in a 78% increase in protein content in the pellet while still containing 84.5% of the total initial total protein. These results show the importance of the right choice when selecting a preservation method and seaweed species for protein extraction. Besides the extracted protein fraction, the remainingpellet also has the potential as a source with an increased protein content.
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Legislation in the Netherlands requires routine analysis of drinking water samples for cultivable Legionella species from high-priority installations. A field study was conducted to investigate the presence of Legionella species in thermostatic shower mixer taps. Water samples and the interior of ten thermostatic shower mixer taps were investigated for cultivable Legionella species. In seven cases, Legionella species was found in at least one of the samples. In four cases, Legionella species was detected in the biofilm on the thermostatic shower mixer taps interior, with the highest values on rubber parts, and in five cases in the cold supply water. These results show that thermostatic shower mixer taps can play a role in exceeding the threshold limit for cultivable Legionella species, but the cold supply water can also be responsible. Practical implications: This study showed that contamination of thermostatic shower mixer taps (TSMTs) with Legionella spp. was frequently observed in combination with contamination of the water system. Consequently, a combined focus is necessary to prevent the proliferation of cultivable Legionella spp. in TSMTs. In addition, the results also demonstrated that biofilms on rubbers inside the TSMT had high numbers of Legionella spp., probably because rubber contains relatively high concentrations of biodegradable substrates. Therefore, improvement of the rubber materials is necessary to reduce the proliferation of cultivable Legionella spp. in TSMTs.
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Global climate change is resulting in a wide range of biotic responses, including changes in diel activity and seasonal phenology patterns, range shifts polewards in each hemisphere and/or to higher elevations, and altered intensity and frequency of interactions between species in ecosystems.Oak (Thaumetopoea processionea) and pine (T. pityocampa) processionary moths (hereafter OPM and PPM, respectively) are thermophilic species that are native to central and southern Europe. The larvae of both species are gregarious and produce large silken ‘nests’ that they use to congregate when not feeding. During outbreaks, processionary caterpillars are capable of stripping foliage from theirfood plants (oak and pine trees), generating considerable economic damage. Moreover, the third to last instar caterpillars of both species produce copious hairs as a means of defence against naturalenemies, including both vertebrate and invertebrate predators, and parasitoids. These hairs contain the toxin thaumetopoein that causes strong allergic reactions when it comes into contact with humanskin or other membranes. In response to a warming climate, PPM is expanding its range northwards, while OPM outbreaks are increasing in frequency and intensity, particularly in northern Germany,the Netherlands, and southern U.K., where it was either absent or rare previously. Here, we discuss how warming and escape from co-evolved natural enemies has benefitted both species, and suggest possible strategies for biological control.
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There is consensus that plant species richness enhances plant productivity within natural grasslands, but the underlying drivers remain debated. Recently, differential accumulation of soil‐borne fungal pathogens across the plant diversity gradient has been proposed as a cause of this pattern. However, the below‐ground environment has generally been treated as a ‘black box’ in biodiversity experiments, leaving these fungi unidentified. Using next generation sequencing and pathogenicity assays, we analysed the community composition of root‐associated fungi from a biodiversity experiment to examine if evidence exists for host specificity and negative density dependence in the interplay between soil‐borne fungi, plant diversity and productivity. Plant species were colonised by distinct (pathogenic) fungal communities and isolated fungal species showed negative, species‐specific effects on plant growth. Moreover, 57% of the pathogenic fungal operational taxonomic units (OTUs) recorded in plant monocultures were not detected in eight plant species plots, suggesting a loss of pathogenic OTUs with plant diversity. Our work provides strong evidence for host specificity and negative density‐dependent effects of root‐associated fungi on plant species in grasslands. Our work substantiates the hypothesis that fungal root pathogens are an important driver of biodiversity‐ecosystem functioning relationships.
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Species responding differently to climate change form ‘transient communities’, communities with constantly changing species composition due to colonization and extinction events. Our goal is to disentangle the mechanisms of response to climate change for terrestrial species in these transient communities and explore the consequences for biodiversity conservation. We review spatial escape and local adaptation of species dealing with climate change from evolutionary and ecological perspectives. From these we derive species vulnerability and management options to mitigate effects of climate change. From the perspective of transient communities, conservation management should scale up static single species approaches and focus on community dynamics and species interdependency, while considering species vulnerability and their importance for the community. Spatially explicit and frequent monitoring is vital for assessing the change in communities and distribution of species. We review management options such as: increasing connectivity and landscape resilience, assisted colonization, and species protection priority in the context of transient communities.
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While Amazonian forests are extraordinarily diverse, the abundance of trees is skewed strongly towards relatively few ‘hyperdominant’species. In addition to their diversity, Amazonian trees are a key component of the global carbon cycle, assimilating and storing morecarbon than any other ecosystem on Earth. Here we ask, using a unique data set of 530 forest plots, if the functions of storing andproducing woody carbon are concentrated in a small number of tree species, whether the most abundant species also dominate carboncycling, and whether dominant species are characterized by specific functional traits.
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Spatial variation in habitat riskiness has a major influence on the predator–prey space race. However, the outcome of this race can be modulated if prey shares enemies with fellow prey (i.e., another prey species). Sharing of natural enemies may result in apparent competition, and its implications for prey space use remain poorly studied. Our objective was to test how prey species spend time among habitats that differ in riskiness, and how shared predation modulates the space use by prey species. We studied a one‐predator, two‐prey system in a coastal dune landscape in the Netherlands with the European hare (Lepus europaeus) and European rabbit (Oryctolagus cuniculus) as sympatric prey species and red fox (Vulpes vulpes) as their main predator. The fine‐scale space use by each species was quantified using camera traps. We quantified residence time as an index of space use. Hares and rabbits spent time differently among habitats that differ in riskiness. Space use by predators and habitat riskiness affected space use by hares more strongly than space use by rabbits. Residence time of hare was shorter in habitats in which the predator was efficient in searching or capturing prey species. However, hares spent more time in edge habitat when foxes were present, even though foxes are considered ambush predators. Shared predation affected the predator–prey space race for hares positively, and more strongly than the predator–prey space race for rabbits, which were not affected. Shared predation reversed the predator–prey space race between foxes and hares, whereas shared predation possibly also released a negative association and promoted a positive association between our two sympatric prey species. Habitat riskiness, species presence, and prey species’ escape mode and foraging mode (i.e., central‐place vs. noncentral‐place forager) affected the prey space race under shared predation.
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The carbon sink capacity of tropical forests is substantially affected by tree mortality. However, the main drivers of tropical tree death remain largely unknown. Here we present a pan-Amazonian assessment of how and why trees die, analysing over 120,000 trees representing > 3800 species from 189 long-term RAINFOR forest plots. While tree mortality rates vary greatly Amazon-wide, on average trees are as likely to die standing as they are broken or uprooted—modes of death with different ecological consequences. Species-level growth rate is the single most important predictor of tree death in Amazonia, with faster growing species being at higher risk. Within species, however, the slowest-growing trees are at greatest risk while the effect of tree size varies across the basin. In the driest Amazonian region species-level bioclimatic distributional patterns also predict the risk of death, suggesting that these forests are experiencing climatic conditions beyond their adaptative limits.These results provide not only a holistic pan-Amazonian picture of tree death but largescale evidence for the overarching importance of the growth–survival trade-off in driving tropical tree mortality.
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In this article, we assess the potential of alternative land use systems using non-drainage peatland species which could eventually phase out or partly replace oil palm plantations on undrainable peatlands. We have used the ecosystem services approach to analyse what scenarios using drainage-free peatland species could be suitable alternatives for oil palm cultivation on peat and how these scenarios compare to oil palm plantations in terms of selected ecosystem services. Our results indicate that alternative paludiculture systems will provide more direct and indirect ecosystem services than oil palm plantations on peat. We also found that stakeholders were aware of issues with growing oil palm on peat, and that there was a general intention for sustainable use of peatlands amongst several groups of stakeholders. Replacing oil palm with alternative systems such as paludiculture in Malaysia is not yet realistic. The most important impediments are a lack of knowledge on potential of non-drainage peatland species and its associated value chains, as well as the technical difficulty for smallholders to implement such a system. We recommend starting experimental plantings with paludiculture systems to further test species performance, life cycle analysis, growth, intercropping limitations and possibilities, yields and improvements in the value chain.
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In this article we focus upon a division between generalized schools of philosophical and ethical thought about culture and conservation. There is an ongoing debate playing out over conservation between those who believe conservation threatens community livelihoods and traditional practices, and those who believe conservation is essential to protect nonhuman species from the impact of human development and population growth. We argue for reconciliation between these schools of thought and a cooperative push toward the cultivation of an environmentally-focused perspective that embraces not only social and economic justice but also concern for non-human species. Our goal is to underline the ethics and tangible benefits that may result from combining the cultural data and knowledge of the social sciences with understanding of environmental science and conservation. We highlight instances in which social scientists overlook their own anthropocentric bias in relationship to ecological justice, or justice for all species, in favor of exclusive social justice among people. We focus on the polemical stances of this debate in order to emphasize the importance of a middle road of cooperation that acknowledges the rights of human and nonhuman species, alike. In conclusion, we present an alternative set of ethics and research activities for social scientists concerned with conservation and offer ideas on how to reconcile the conflicting interests of people and the environment. https://doi.org/10.1016/j.biocon.2015.01.030 https://www.linkedin.com/in/helenkopnina/
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