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排序方式: 共有349条查询结果,搜索用时 31 毫秒
1.
Danica Antonijević Mathias Hoffmann Annette Prochnow Karoline Krabbe Mirjam Weituschat John Couwenberg Sigrid Ehlert Dominik Zak Jürgen Augustin 《Global Change Biology》2023,29(13):3678-3691
Drainage and agricultural use transform natural peatlands from a net carbon (C) sink to a net C source. Rewetting of peatlands, despite of high methane (CH4) emissions, holds the potential to mitigate climate change by greatly reducing CO2 emissions. However, the time span for this transition is unknown because most studies are limited to a few years. Especially, nonpermanent open water areas often created after rewetting, are highly productive. Here, we present 14 consecutive years of CH4 flux measurements following rewetting of a formerly long-term drained peatland in the Peene valley. Measurements were made at two rewetted sites (non-inundated vs. inundated) using manual chambers. During the study period, significant differences in measured CH4 emissions occurred. In general, these differences overlapped with stages of ecosystem transition from a cultivated grassland to a polytrophic lake dominated by emergent helophytes, but could also be additionally explained by other variables. This transition started with a rapid vegetation shift from dying cultivated grasses to open water floating and submerged hydrophytes and significantly increased CH4 emissions. Since 2008, helophytes have gradually spread from the shoreline into the open water area, especially in drier years. This process was periodically delayed by exceptional inundation and eventually resulted in the inundated site being covered by emergent helophytes. While the period between 2009 and 2015 showed exceptionally high CH4 emissions, these decreased significantly after cattail and other emergent helophytes became dominant at the inundated site. Therefore, CH4 emissions declined only after 10 years of transition following rewetting, potentially reaching a new steady state. Overall, this study highlights the importance of an integrative approach to understand the shallow lakes CH4 biogeochemistry, encompassing the entire area with its mosaic of different vegetation forms. This should be ideally done through a study design including proper measurement site allocation as well as long-term measurements. 相似文献
2.
Lasse T. Keetz Eva Lieungh Kaveh Karimi-Asli Sonya R. Geange Emiliano Gelati Hui Tang Yeliz A. Yilmaz Kjetil S. Aas Inge H. J. Althuizen Anders Bryn Stefanie Falk Rosie Fisher Anne Fouilloux Peter Horvath Sunniva Indrehus Hanna Lee Danica Lombardozzi Frans-Jan W. Parmentier Norbert Pirk Vigdis Vandvik Ane V. Vollsnes Olav Skarpaas Frode Stordal Lena M. Tallaksen 《Global Change Biology》2023,29(15):4440-4452
Dynamic Global Vegetation Models (DGVMs) provide a state-of-the-art process-based approach to study the complex interplay between vegetation and its physical environment. For example, they help to predict how terrestrial plants interact with climate, soils, disturbance and competition for resources. We argue that there is untapped potential for the use of DGVMs in ecological and ecophysiological research. One fundamental barrier to realize this potential is that many researchers with relevant expertize (ecology, plant physiology, soil science, etc.) lack access to the technical resources or awareness of the research potential of DGVMs. Here we present the Land Sites Platform (LSP): new software that facilitates single-site simulations with the Functionally Assembled Terrestrial Ecosystem Simulator, an advanced DGVM coupled with the Community Land Model. The LSP includes a Graphical User Interface and an Application Programming Interface, which improve the user experience and lower the technical thresholds for installing these model architectures and setting up model experiments. The software is distributed via version-controlled containers; researchers and students can run simulations directly on their personal computers or servers, with relatively low hardware requirements, and on different operating systems. Version 1.0 of the LSP supports site-level simulations. We provide input data for 20 established geo-ecological observation sites in Norway and workflows to add generic sites from public global datasets. The LSP makes standard model experiments with default data easily achievable (e.g., for educational or introductory purposes) while retaining flexibility for more advanced scientific uses. We further provide tools to visualize the model input and output, including simple examples to relate predictions to local observations. The LSP improves access to land surface and DGVM modelling as a building block of community cyberinfrastructure that may inspire new avenues for mechanistic ecosystem research across disciplines. 相似文献
3.
Lon J. VanWinkle Danica Dabich 《Biochemical and biophysical research communications》1977,78(1):357-363
Uptake of 14C-labelled α-amino isobutyric acid and a mixture of naturally occurring amino acids by normal mouse preimplantation blastocysts was found to be twice that of delayed implantation blastocysts. With both groups of embryos concentration of the amino acids against a gradient occurred. The results may explain, in part, the lower amino acid incorporation rates found with diapausing vs. normal blastocysts and open the question of “metabolic dormancy” of the diapausing embryo. 相似文献
4.
This review focuses on utilization of plant lectins as medical diagnostic reagents and tools. The lectin-related diagnostic
is aimed at detection of several diseases connected to alteration of the glycosylation profiles of cells and at identification
of microbial and viral agents in clinical microbiology. Certain lectins, proposed for or used as diagnostic tools could even
recognize those cellular determinants, which are not detected by available antibodies. Broad information is presented on the
lectinomics field, illustrating that lectin diagnostics might become practical alternative to antibody-based diagnostic products.
In addition, the rising trend of lectin utilization in biomedical diagnostics might initiate a development of innovative methods
based on better analytical technologies. Lectin microarray, a rapid and simple methodology, can be viewed as an example for
such initiative. This technology could provide simple and efficient screening tools for analysis of glycosylation patterns
in biological samples (cellular extracts, tissues and the whole cells), allowing thus personalized detection of changes associated
with carbohydrate-related diseases. 相似文献
5.
Luis Garreta Ivania CernSouza Manfred Ricardo Palacio Paula H. ReyesHerrera 《Ecology and evolution》2021,11(12):7411
The genome‐wide association studies (GWASs) are essential to determine the genetic bases of either ecological or economic phenotypic variation across individuals within populations of the model and nonmodel organisms. For this research question, the GWAS replication testing different parameters and models to validate the results'' reproducibility is common. However, straightforward methodologies that manage both replication and tetraploid data are still missing. To solve this problem, we designed the MultiGWAS, a tool that does GWAS for diploid and tetraploid organisms by executing in parallel four software packages, two designed for polyploid data (GWASpoly and SHEsis) and two designed for diploid data (GAPIT and TASSEL). MultiGWAS has several advantages. It runs either in the command line or in a graphical interface; it manages different genotype formats, including VCF. Moreover, it allows control for population structure, relatedness, and several quality control checks on genotype data. Besides, MultiGWAS can test for additive and dominant gene action models, and, through a proprietary scoring function, select the best model to report its associations. Finally, it generates several reports that facilitate identifying false associations from both the significant and the best‐ranked association Single Nucleotide Polymorphisms (SNPs) among the four software packages. We tested MultiGWAS with public tetraploid potato data for tuber shape and several simulated data under both additive and dominant models. These tests demonstrated that MultiGWAS is better at detecting reliable associations than using each of the four software packages individually. Moreover, the parallel analysis of polyploid and diploid software that only offers MultiGWAS demonstrates its utility in understanding the best genetic model behind the SNP association in tetraploid organisms. Therefore, MultiGWAS probed to be an excellent alternative for wrapping GWAS replication in diploid and tetraploid organisms in a single analysis environment. 相似文献
6.
Jeongmin Yun Sujong Jeong Chang‐Hoi Ho Hoonyoung Park Junjie Liu Haeyoung Lee Stephen Sitch Pierre Friedlingstein Sebastian Lienert Danica Lombardozzi Vanessa Haverd Atual Jain Snke Zaehle Etsushi Kato Hanqin Tian Nicolas Vuichard Andy Wiltshire Ning Zeng 《Global Change Biology》2020,26(6):3368-3383
Understanding changes in terrestrial carbon balance is important to improve our knowledge of the regional carbon cycle and climate change. However, evaluating regional changes in the terrestrial carbon balance is challenging due to the lack of surface flux measurements. This study reveals that the terrestrial carbon uptake over the Republic of Korea has been enhanced from 1999 to 2017 by analyzing long‐term atmospheric CO2 concentration measurements at the Anmyeondo Station (36.53°N, 126.32°E) located in the western coast. The influence of terrestrial carbon flux on atmospheric CO2 concentrations (ΔCO2) is estimated from the difference of CO2 concentrations that were influenced by the land sector (through easterly winds) and the Yellow Sea sector (through westerly winds). We find a significant trend in ΔCO2 of ?4.75 ppm per decade (p < .05) during the vegetation growing season (May through October), suggesting that the regional terrestrial carbon uptake has increased relative to the surrounding ocean areas. Combined analysis with satellite measured normalized difference vegetation index and gross primary production shows that the enhanced carbon uptake is associated with significant nationwide increases in vegetation and its production. Process‐based terrestrial model and inverse model simulations estimate that regional terrestrial carbon uptake increases by up to 18.9 and 8.0 Tg C for the study period, accounting for 13.4% and 5.7% of the average annual domestic carbon emissions, respectively. Atmospheric chemical transport model simulations indicate that the enhanced terrestrial carbon sink is the primary reason for the observed ΔCO2 trend rather than anthropogenic emissions and atmospheric circulation changes. Our results highlight the fact that atmospheric CO2 measurements could open up the possibility of detecting regional changes in the terrestrial carbon cycle even where anthropogenic emissions are not negligible. 相似文献
7.
Facundo Xavier Palacio 《Ibis》2020,162(1):42-49
Urbanization is currently one of the most pervasive threats to biodiversity worldwide, yet traits permitting birds to exploit urban environments are not fully understood. I used bird traits related to diet (dietary item and foraging stratum), accounting for latitude, body size, development mode and phylogeny, to compare diet breadths of urban exploiters and urban avoiders, using a global dataset (463 bird species). Urban exploiters (urban species) were larger, consumed more vertebrates and carrion, and fed more frequently on the ground or aerially, and also had broader diets than urban avoiders (non-urban species). In contrast, urban species had narrower foraging strata ranges than non-urban species. These results not only support the hypothesis that urban species share dietary traits allowing them to cope with urban environments but also highlight the importance of considering multiple dietary traits to properly quantify species niches when assessing a species’ response to environmental change. 相似文献
8.
9.
Analysis of plant–frugivore interactions provides a quantitative framework for integrating community structure and ecosystem function in terms of how the roles and attributes of individual species contribute to network structure and resilience. In this study, we used centrality metrics to rank and detect the most important species in a mutualistic network of fruit‐eating birds and plants in a cloud forest in the Colombian Andes. We identified a central core of ten bird and seven plant species in a network of 135 species that perform dual roles as local hubs and connectors. The birds were mostly large forest frugivores, such as cracids, cotingas, and toucans, which consume fruits of all sizes. The plants were species of intermediate successional stages with small‐ to medium‐sized seeds that persist in mature forest or forest borders (e.g., Miconia, Cecropia, Ficus). We found the resilience of our network depends on super‐generalist species, because their elimination makes the network more prone to disassemble than random extinctions, potentially disrupting seed‐dispersal processes. At our study site, extirpation of large frugivores has already been documented, and if this continues, the network might collapse despite its high diversity. Our results suggest that generalist species play critical roles in ecosystem function and should be incorporated into conservation and monitoring programs. 相似文献
10.
Unravelling the mechanisms for plant survival on gypsum soils: an analysis of the chemical composition of gypsum plants from Turkey
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Depending on their specificity to gypsum, plants can be classified as gypsophiles (gypsum exclusive) and gypsovags (non‐exclusive). The former may further be segregated into wide and narrow gypsophiles, depending on the breadth of their distribution area. Narrow gypsum endemics have a putative similar chemical composition to plants non‐exclusive to gypsum (i.e. gypsovags), which may indicate their similar ecological strategy as stress‐tolerant plant refugees on gypsum. However, this hypothesis awaits testing in different regions of the world. We compared the chemical composition of four narrow gypsum endemics, one widely distributed gypsophile and six gypsovags from Turkey. Further, we explored the plasticity in chemical composition of Turkish gypsovags growing on high‐ and low‐gypsum content soils. Differences were explored with multivariate analyses (RDA) and mixed models (REML). Narrow gypsum endemics segregated from gypsovags in their chemical composition according to RDAs (mainly due to higher K and ash content in the former). Nevertheless, differences were small and disappeared when different nutrients were analysed individually. All the gypsovags studied accumulated more S and ash when growing on high‐gypsum than on low‐gypsum soils. Similar to narrow gypsum endemics from other regions of the world, most local gypsum endemics from Turkey show a similar chemical composition to gypsovags. This may indicate a shared ecological strategy as stress‐tolerant plants not specifically adapted to gypsum. Nevertheless, the narrow gypsum endemic Gypsophila parva showed a chemical composition typical of gypsum specialists, indicating that various strategies are feasible within narrowly distributed gypsophiles. 相似文献