排序方式: 共有42条查询结果,搜索用时 31 毫秒
1.
Habacuc Flores‐Moreno Farideh Fazayeli Arindam Banerjee Abhirup Datta Jens Kattge Ethan E. Butler Owen K. Atkin Kirk Wythers Ming Chen Madhur Anand Michael Bahn Chaeho Byun J. Hans C. Cornelissen Joseph Craine Andres Gonzalez‐Melo Wesley N. Hattingh Steven Jansen Nathan J. B. Kraft Koen Kramer Daniel C. Laughlin Vanessa Minden Ülo Niinemets Vladimir Onipchenko Josep Peuelas Nadejda A. Soudzilovskaia Rhiannon L. Dalrymple Peter B. Reich 《Global Ecology and Biogeography》2019,28(12):1806-1826
2.
Paulo FP Pimenta Alessandra S Orfano Ana C Bahia Ana PM Duarte Claudia M Ríos-Velásquez Fabrício F Melo Felipe AC Pessoa Giselle A Oliveira Keillen MM Campos Luis Martínez Villegas Nilton Barnabé Rodrigues Rafael Nacif-Pimenta Rejane C Sim?es Wuelton M Monteiro Rogerio Amino Yara M Traub-Cseko José BP Lima Maria GV Barbosa Marcus VG Lacerda Wanderli P Tadei Nágila FC Secundino 《Memórias do Instituto Oswaldo Cruz》2015,110(1):23-47
In the Americas, areas with a high risk of malaria transmission are mainly located in
the Amazon Forest, which extends across nine countries. One keystone step to
understanding the Plasmodium life cycle in Anopheles species from the Amazon Region
is to obtain experimentally infected mosquito vectors. Several attempts to colonise
Ano- pheles species have been conducted, but with only short-lived success or no
success at all. In this review, we review the literature on malaria transmission from
the perspective of its Amazon vectors. Currently, it is possible to develop
experimental Plasmodium vivax infection of the colonised and field-captured vectors
in laboratories located close to Amazonian endemic areas. We are also reviewing
studies related to the immune response to P. vivax infection of Anopheles aquasalis,
a coastal mosquito species. Finally, we discuss the importance of the modulation of
Plasmodium infection by the vector microbiota and also consider the anopheline
genomes. The establishment of experimental mosquito infections with Plasmodium
falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide
interesting models for studying malaria in the Amazonian scenario is important.
Understanding the molecular mechanisms involved in the development of the parasites
in New World vectors is crucial in order to better determine the interaction process
and vectorial competence. 相似文献
3.
Vladimir G. Onipchenko Mikhail S. Blinnikov Maria A. Gerasimova Elena V. Volkova Johannes H.C. Cornelissen 《植被学杂志》2009,20(4):718-727
Question. Competitive and facilitative interactions among plant species in different abiotic environments potentially link productivity, vegetation structure, species composition and functional diversity. We investigated these interactions among four alpine communities along an environmental productivity gradient in a generally harsh climate. We hypothesised that the importance of competition would be higher in more productive sites. Location. Mt. M. Khatipara (43°27′N, 41°41′E, altitude 2750 m), NW Caucasus, Russia. Communities ranged from low‐productivity alpine lichen heath (ALH) and snowbed communities (SBC), to intermediate productivity Festuca grassland (FVG), and high‐productivity Geranium‐Hedysarum meadow (GHM). Methods. We quantified the relative influence of competition and facilitation on community structure by expressing biomass of target species within each natural community proportionally to biomass of the species in a “null community” with experimental release from interspecific competition by removing all other species (for 6 years). An overall index of change in community composition due to interspecific interactions was calculated as the sum of absolute or proportional differences of the component species. Results. Species responses to neighbour removal ranged from positive to neutral. There was no evidence of facilitation among the selected dominant species. As expected, competition was generally most important in the most productive alpine community (GHM). The intermediate position for low‐productivity communities of stressful environments (ALH, SBC) and the last position of intermediately productive FVG were unexpected. Conclusions. Our results appear to support the Fretwell‐Oksanen hypothesis in that competition in communities of intermediate productivity was less intense than in low‐ or high‐productive communities. However, the zero net effect of competition and facilitation in FVG might be the result of abiotic stress due to strong sun exposure and high soil temperatures after neighbour removal. Thus, non‐linear relationships between soil fertility, productivity and different abiotic stresses may also determine the balance between competition and facilitation. 相似文献
4.
Vladimir G. Onipchenko Mikhail I. Makarov Richard S. P. van Logtestijn Viktor B. Ivanov Assem A. Akhmetzhanova Dzhamal K. Tekeev Anton A. Ermak Fatima S. Salpagarova Anna D. Kozhevnikova Johannes H. C. Cornelissen 《Ecology letters》2009,12(8):758-764
The evolution of plants has yielded a wealth of adaptations for the acquisition of key mineral nutrients. These include the structure, physiology and positioning of root systems. We report the discovery of specialized snow roots as a plant strategy to cope with the very short season for nutrient uptake and growth in alpine snow-beds, i.e. patches in the landscape that remain snow-covered well into the summer. We provide anatomical, chemical and experimental 15 N isotope tracking evidence that the Caucasian snow-bed plant Corydalis conorhiza forms extensive networks of specialized above-ground roots, which grow against gravity to acquire nitrogen directly from within snow packs. Snow roots capture nitrogen that would otherwise partly run off down-slope over a frozen surface, thereby helping to nourish these alpine ecosystems. Climate warming is changing and will change mountain snow regimes, while large-scale anthropogenic N deposition has increased snow N contents. These global changes are likely to impact on the distribution, abundance and functional significance of snow roots. 相似文献
5.
Vladimir G. Onipchenko Alii M. Kipkeev Mikhail I. Makarov Anna D. Kozhevnikova Victor B. Ivanov Nadejda A. Soudzilovskaia Dzhamal K. Tekeev Fatima S. Salpagarova Marinus J. A. Werger Johannes H. C. Cornelissen 《Ecological Research》2014,29(4):529-534
Snow roots are specialized structures recently discovered in the Caucasian alpine snow-bed plant Corydalis conorhiza. They form extensive networks that grow into snow packs against gravity, most probably to gather nitrogen from snow. Here we test the hypothesis that snow roots are true winter organs, i.e., they should already start growth early in winter to lay down the infrastructure for N capture from snow packs well before their melt-out. This would require winter surface and soil temperatures continuously close to or above freezing. Excavations of snow roots from snow packs in January and May, accompanied by temperature recordings and anatomical observations, supported our hypothesis. These findings complete the annual cycle of snow root phenology. They also emphasize the evolutionary and ecological significance of these specialized winter organs. Moreover, their likely association with a particular abiotic temperature and snow regime will facilitate the search for snow roots in other species. 相似文献
6.
Omaira Vera Lizcano Sarah Stela Resende Yonne F Chehuan Marcus VG Lacerda Cristiana FA Brito Mariano G Zalis 《Memórias do Instituto Oswaldo Cruz》2014,109(7):948-951
The molecular basis of Plasmodium vivax chloroquine (CQ) resistance
is still unknown. Elucidating the molecular background of parasites that are
sensitive or resistant to CQ will help to identify and monitor the spread of
resistance. By genotyping a panel of molecular markers, we demonstrate a similar
genetic variability between in vitro CQ-resistant and sensitive phenotypes of
P. vivax parasites. However, our studies identified two
loci (MS8 and MSP1-B10) that could be used to discriminate
between both CQ-susceptible phenotypes among P. vivax isolates in
vitro. These preliminary data suggest that microsatellites may be used to identify
and to monitor the spread of P. vivax-resistance around the
world. 相似文献
7.
Is intensity of plant root mycorrhizal colonization a good proxy for plant growth rate,dominance and decomposition in nutrient poor conditions? 下载免费PDF全文
Tatiana G. Elumeeva Vladimir G. Onipchenko Johannes H. C. Cornelissen Galina V. Semenova Lidia G. Perevedentseva Grégoire T. Freschet Richard S. P. van Logtestijn Nadejda A. Soudzilovskaia 《植被学杂志》2018,29(4):715-725
Questions
Mycorrhizae may be a key element of plant nutritional strategies and of carbon and nutrient cycling. Recent research suggests that in natural conditions, intensity of mycorrhizal colonization should be considered an important plant feature. How are inter‐specific variations in mycorrhizal colonization rate, plant relative growth rate (RGR ) and leaf litter decomposability related? Is (arbuscular) mycorrhizal colonization linked to the dominance of plant species in nutrient‐stressed ecosystems?Location
Teberda State Biosphere Reserve, northwest Caucasus, Russia.Methods
We measured plant RGR under mycorrhizal limitation and under natural nutrition conditions, together with leaf litter decomposability and field intensity of mycorrhizal colonization across a wide range of plant species, typical for alpine communities of European mountains. We applied regression analysis to test whether the intensity of mycorrhizal colonization is a good predictor of RGR and decomposition rate, and tested how these traits predict plant dominance in communities.Results
Forb species with a high level of field mycorrhizal colonization had lower RGR under nutritional and mycorrhizal limitation, while grasses were unaffected. Litter decomposition rate was not related to the intensity of mycorrhizal colonization. Dominant species mostly had a higher level of mycorrhizal colonization and lower RGR without mycorrhizal colonization than subordinate species, implying that they were more dependent on mycorrhizal symbionts. There were no differences in litter decomposability.Conclusions
In alpine herbaceous plant communities dominated by arbuscular mycorrhizae, nutrient dynamics are to a large extent controlled by mycorrhizal symbiosis. Intensity of mycorrhizal colonization is a negative predictor for whole plant RGR . Our study highlights the importance of mycorrhizal colonization as a key trait underpinning the role of plant species in carbon and nutrient dynamics in nutrient‐limited herbaceous plant communities.8.
V. G. Onipchenko M. I. Makarov A. A. Akhmetzhanova N. A. Soudzilovskaia F. U. Aibazova M. K. Elkanova A. V. Stogova J. H. C. Cornelissen 《Plant and Soil》2012,357(1-2):103-115
Background and aims
We ask how productivity responses of alpine plant communities to increased nutrient availability can be predicted from abiotic regime and initial functional type composition.Methods
We compared four Caucasian alpine plant communities (lichen heath, Festuca varia grassland, Geranium-Hedysarum meadow, snow bed community) forming a toposequence and contrasting in productivity and dominance structure for biomass responses to experimental fertilization (N, P, NP, Ca) and irrigation for 4–5?years.Results
The dominant plants in more productive communities monopolized added N and P, at the expense of their neighbors. In three out of four communities, N and P fertilizations gave greater aboveground biomass increase than N or P fertilization alone, indicating overall co-limitation of N and P, with N being most limiting. Relative biomass increase in NP treatment was negatively related to biomass in control plots across the four communities. Grasses often responded more vigorously to P, but sedges to N alone. Finally, we present one of the rare examples of a forb showing a strong N or NP response.Conclusion
Our findings will help improve our ability to predict community composition and biomass dynamics in cool ecosystems subject to changing nutrient availability as induced by climate or land-use changes. 相似文献9.
Akhmetzhanova AA Onipchenko VG Él'kanova MKh Stogova AV Tekeev DK 《Zhurnal obshche? biologii》2011,72(5):388-400
Plants growing on rich soil usually have thin leaves with large specific leaf area. On the other hand, at intraspecific level; soil fertilization results in leaves size increasing which, in turn, can lead to reduction in specific leaf area. To what extent soil fertilization implies only leaves increasing in size and does not affect other eco-morphological characteristics is a question that is still open. To assess coherence between plants intraspecific reactions to changes in soil richness and general tendencies in changes of leaves parameters in communities with different productivity, an experiment has been conducted in alpine plant communities of the north-western Caucasus. Changes in leaf traits are studied in four types of alpine plant communities after long term application of mineral nutrients (NP and lime treatment). It is shown that in all species, except legume Hedysarum caucasicum, fertilization results in size leaf characteristics (leaf area, wet and dry mass) increase. Specific leaf area appears to decrease in plants inhabiting alpine heathlands and increase in plants inhabiting alpine snow beds and in dominant species of Geranium-Hedysarum meadows, Geranium gymnocaulon. After correction of specific leaf area that accounts for changes in leaf size, it becomes discernable that in most species the increase in leaf area per se results in specific leaf area reduction while changes in leaf structure under influence of fertilization leads to this trait increasing. Those species demonstrating the increase in specific leaf area as an effect of fertilization, also gain more in terms of biomass. 相似文献
10.