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1.
Proc Natl Acad Sci U S A ; 120(25): e2301727120, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-37307460

RESUMO

Poaching for horns and tusks is driving declines of megaherbivores worldwide, including the critically endangered African black rhinoceros (Diceros bicornis). By proactively dehorning entire rhinoceros populations, conservationists aim to deter poaching and prevent species loss. However, such conservation interventions may have hidden and underestimated effects on animals' behavior and ecology. Here, we combine >15 y of black rhino-monitoring data across 10 South African game reserves, comprising >24,000 sightings of 368 individuals, to determine the consequences of dehorning for black rhino space use and social interactions. While preventative dehorning at these reserves coincided with a nationwide decrease in black rhino mortality from poaching and did not infer increased natural mortality, dehorned black rhinos decreased their home range area by, on average, 11.7 km2 (45.5%) and were 37% less likely to engage in social encounters. We conclude that dehorning black rhinos as an antipoaching measure alters their behavioral ecology, although the potential population-level effects of these changes remain to be determined.


Assuntos
Comportamento de Retorno ao Território Vital , Perissodáctilos , Interação Social , Animais , Comportamento Animal
2.
Proc Natl Acad Sci U S A ; 118(3)2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33431671

RESUMO

To cope with environmental challenges, plants produce a wide diversity of phytochemicals, which are also the source of numerous medicines. Despite decades of research in chemical ecology, we still lack an understanding of the organization of plant chemical diversity across species and ecosystems. To address this challenge, we hypothesized that molecular diversity is not only related to species diversity, but also constrained by trophic, climatic, and topographical factors. We screened the metabolome of 416 vascular plant species encompassing the entire alpine elevation range and four alpine bioclimatic regions in order to characterize their phytochemical diversity. We show that by coupling phylogenetic information, topographic, edaphic, and climatic variables, we predict phytochemical diversity, and its inherent composition, of plant communities throughout landscape. Spatial mapping of phytochemical diversity further revealed that plant assemblages found in low to midelevation habitats, with more alkaline soils, possessed greater phytochemical diversity, whereas alpine habitats possessed higher phytochemical endemism. Altogether, we present a general tool that can be used for predicting hotspots of phytochemical diversity in the landscape, independently of plant species taxonomic identity. Such an approach offers promising perspectives in both drug discovery programs and conservation efforts worldwide.


Assuntos
Metaboloma , Compostos Fitoquímicos/classificação , Plantas/química , Plantas/classificação , Altitude , Biodiversidade , Clima , Conservação dos Recursos Naturais/métodos , Descoberta de Drogas/métodos , Ecossistema , Europa (Continente) , Concentração de Íons de Hidrogênio , Filogenia , Compostos Fitoquímicos/biossíntese , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Plantas/genética , Plantas/metabolismo , Solo/química , Temperatura
3.
J Med Ethics ; 48(1): 61-64, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-32354791

RESUMO

Accounts of the value of patient choice in contemporary medical ethics typically focus on the act of choosing. Being the one to choose, it is argued, can be valuable either because it enables one to bring about desired outcomes, or because it is a way of enacting one's autonomy. This paper argues that all such accounts miss something important. In some circumstances, it is having the opportunity to choose, not the act of choosing, that is valuable. That is because in many situations whether one has, or is denied, that opportunity conveys how one is seen. In particular, it conveys whether or not one is seen as an equal and competent member of society. Adequately recognising this fact has implications for what healthcare professionals should do, ones that require a move away from the current focus on autonomy. The paper draws out these implications by focusing on patients who may struggle to be recognised as competent and equal members of society, and whose autonomy may thus itself sometimes be in question.


Assuntos
Ética Médica , Cuidados Paliativos , Humanos , Autonomia Pessoal
4.
Curr Microbiol ; 80(1): 13, 2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36459292

RESUMO

Microbial carbon use efficiency (CUE)-the balance between microbial growth and respiration-strongly impacts microbial mediated soil carbon storage and is sensitive to many well-studied abiotic environmental factors. However, surprisingly, little work has examined how biotic interactions in soil may impact CUE. Here, we review the theoretical and empirical lines of evidence exploring how biotic interactions affect CUE through the lens of life history strategies. Fundamentally, the CUE of a microbial population is constrained by population density and carrying capacity, which, when reached, causes species to grow more quickly and less efficiently. When microbes engage in interspecific competition, they accelerate growth rates to acquire limited resources and release secondary chemicals toxic to competitors. Such processes are not anabolic and thus constrain CUE. In turn, antagonists may activate one of a number of stress responses that also do not involve biomass production, potentially further reducing CUE. In contrast, facilitation can increase CUE by expanding species realized niches, mitigating environmental stress and reducing production costs of extracellular enzymes. Microbial interactions at higher trophic levels also influence CUE. For instance, predation on microbes can positively or negatively impact CUE by changing microbial density and the outcomes of interspecific competition. Finally, we discuss how plants select for more or less efficient microbes under different contexts. In short, this review demonstrates the potential for biotic interactions to be a strong regulator of microbial CUE and additionally provides a blueprint for future research to address key knowledge gaps of ecological and applied importance for carbon sequestration.


Assuntos
Carbono , Solo , Biomassa , Interações Microbianas
5.
Cleft Palate Craniofac J ; 59(5): 644-651, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34192974

RESUMO

INTRODUCTION: Tessier 30 facial cleft is a rare anomaly presenting in the soft and hard tissues over the central lower face. Owing to the rarity of cases and difficulty of treatment, there is no universally accepted surgical management strategy. The last comprehensive literature review of Tessier 30 clefts was in 1996. This report aims to update the literature to inform decision-making on treating Tessier 30 cases. METHODOLOGY: A literature search was performed. PubMed, SCOPUS, and OVID databases were searched. A total of 72 cases in 51 articles were analyzed, looking at demographics, extent of cleft, parent health, family history, procedures, follow-up, existence of other anomalies, and stages of repair. RESULTS: Surgeons are increasingly choosing to repair Tessier 30 defects in one rather than multiple stages. Of the 72 cases studied, only 31 had documented the completed repair of the cleft. All completed soft tissue only defects were repaired in 1 stage of repair (n = 11). Where both soft tissue and mandible was involved (n = 20), 55% (n = 11) had undergone 1-stage repair to address the Tessier 30 cleft. DISCUSSION: We argue that a single-stage approach is preferable to multistage. Primary mucogingivoperiosteoplasty should be undertaken in children at the time of management of the soft tissue cleft. The timing of this procedure should be in the latter half of the first year of life, as this is when mandibular symphyseal fusion normally occurs. We have suggested a treatment protocol and we hope that future case reports use our minimum data set.


Assuntos
Fenda Labial , Procedimentos de Cirurgia Plástica , Criança , Fenda Labial/cirurgia , Protocolos Clínicos , Humanos , Avaliação de Resultados em Cuidados de Saúde , Procedimentos de Cirurgia Plástica/métodos , Sistema de Registros , Literatura de Revisão como Assunto
6.
Glob Chang Biol ; 26(2): 669-681, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31344298

RESUMO

Species-rich plant communities have been shown to be more productive and to exhibit increased long-term soil organic carbon (SOC) storage. Soil microorganisms are central to the conversion of plant organic matter into SOC, yet the relationship between plant diversity, soil microbial growth, turnover as well as carbon use efficiency (CUE) and SOC accumulation is unknown. As heterotrophic soil microbes are primarily carbon limited, it is important to understand how they respond to increased plant-derived carbon inputs at higher plant species richness (PSR). We used the long-term grassland biodiversity experiment in Jena, Germany, to examine how microbial physiology responds to changes in plant diversity and how this affects SOC content. The Jena Experiment considers different numbers of species (1-60), functional groups (1-4) as well as functional identity (small herbs, tall herbs, grasses, and legumes). We found that PSR accelerated microbial growth and turnover and increased microbial biomass and necromass. PSR also accelerated microbial respiration, but this effect was less strong than for microbial growth. In contrast, PSR did not affect microbial CUE or biomass-specific respiration. Structural equation models revealed that PSR had direct positive effects on root biomass, and thereby on microbial growth and microbial biomass carbon. Finally, PSR increased SOC content via its positive influence on microbial biomass carbon. We suggest that PSR favors faster rates of microbial growth and turnover, likely due to greater plant productivity, resulting in higher amounts of microbial biomass and necromass that translate into the observed increase in SOC. We thus identify the microbial mechanism linking species-rich plant communities to a carbon cycle process of importance to Earth's climate system.


Assuntos
Carbono , Solo , Biomassa , Alemanha , Microbiologia do Solo
7.
Ecol Lett ; 22(1): 159-169, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30556313

RESUMO

Climate warming affects plant physiology through genetic adaptation and phenotypic plasticity, but little is known about how these mechanisms influence ecosystem processes. We used three elevation gradients and a reciprocal transplant experiment to show that temperature causes genetic change in the sedge Eriophorum vaginatum. We demonstrate that plants originating from warmer climate produce fewer secondary compounds, grow faster and accelerate carbon dioxide (CO2 ) release to the atmosphere. However, warmer climate also caused plasticity in E. vaginatum, inhibiting nitrogen metabolism, photosynthesis and growth and slowing CO2 release into the atmosphere. Genetic differentiation and plasticity in E. vaginatum thus had opposing effects on CO2 fluxes, suggesting that warming over many generations may buffer, or reverse, the short-term influence of this species over carbon cycle processes. Our findings demonstrate the capacity for plant evolution to impact ecosystem processes, and reveal a further mechanism through which plants will shape ecosystem responses to climate change.


Assuntos
Ciclo do Carbono , Plásticos , Carbono , Dióxido de Carbono , Mudança Climática , Ecossistema , Plantas
8.
Cleft Palate Craniofac J ; 56(9): 1249-1252, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30971098

RESUMO

Midline clefts of the lower lip, tongue, and mandible are a rare type of facial cleft classified as "Tessier 30." We present the case of a female patient with an isolated Tessier 30 facial cleft affecting the tongue, lower lip, and mandibular symphysis with ankyloglossia. This was reconstructed with a template-guided resorbable "U"-shaped plate at 10 months of age. The procedure was carried out in one stage, which avoided the need for a repeat general anesthetic for the patient. We had a successful outcome with normal dental eruption and we believe such an approach could be considered as a relevant treatment modality for future cases.


Assuntos
Fenda Labial , Fissura Palatina , Feminino , Humanos , Lábio , Mandíbula , Língua
9.
Am J Public Health ; 108(3): 343-348, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29346005

RESUMO

Social media (SM) offer huge potential for public health research, serving as a vehicle for surveillance, delivery of health interventions, recruitment to trials, collection of data, and dissemination. However, the networked nature of the data means they are riddled with ethical challenges, and no clear consensus has emerged as to the ethical handling of such data. This article outlines the key ethical concerns for public health researchers using SM and discusses how these concerns might best be addressed. Key issues discussed include privacy; anonymity and confidentiality; authenticity; the rapidly changing SM environment; informed consent; recruitment, voluntary participation, and sampling; minimizing harm; and data security and management. Despite the obvious need, producing a set of prescriptive guidelines for researchers using SM is difficult because the field is evolving quickly. What is clear, however, is that the ethical issues connected to SM-related public health research are also growing. Most importantly, public health researchers must work within the ethical principles set out by the Declaration of Helsinki that protect individual users first and foremost.


Assuntos
Pesquisa sobre Serviços de Saúde/ética , Saúde Pública/métodos , Mídias Sociais , Confidencialidade , Humanos , Consentimento Livre e Esclarecido , Privacidade , Projetos de Pesquisa
10.
Soil Biol Biochem ; 117: 16-26, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31579255

RESUMO

The 15N isotope pool dilution (IPD) technique is the only available method for measuring gross ammonium (NH4 +) production and consumption rates. Rapid consumption of the added 15N-NH4 + tracer is commonly observed, but the processes responsible for this consumption are not well understood. The primary objectives of this study were to determine the relative roles of biotic and abiotic processes in 15N-NH4 + sconsumption and to investigate the validity of one of the main assumptions of IPD experiments, i.e., that no reflux of the consumed 15N tracer occurs during the course of the experiments. We added a 15N-NH4 + tracer to live and sterile (autoclaved) soil using mineral topsoil from a beech forest and a grassland in Austria that differed in NH4 + concentrations and NH4 + consumption kinetics. We quantified both biotic tracer consumption (i.e. changes in the concentrations and 15N enrichments of NH4 +, dissolved organic N (DON), NO3 - and the microbial N pool) and abiotic tracer consumption (i.e., fixation by clay and/or humic substances). We achieved full recovery of the 15N tracer in both soils over the course of the 48 h incubation. For the forest soil, we found no rapid consumption of the 15N tracer, and the majority of tracer (78%) remained unconsumed at the end of the incubation period. In contrast, the grassland soil showed rapid 15N-NH4 + consumption immediately after tracer addition, which was largely due to both abiotic fixation (24%) and biotic processes, largely uptake by soil microbes (10%) and nitrification (13%). We found no evidence for reflux of 15N-NH4 + over the 48 h incubation period in either soil. Our study therefore shows that 15N tracer reflux during IPD experiments is negligible for incubation times of up to 48 h, even when rapid NH4 + consumption occurs. Such experiments are thus robust to the assumption that immobilized labeled N is not re-mobilized during the experimental period and does not impact calculations of gross N mineralization.

11.
Kennedy Inst Ethics J ; 27(4): 501-524, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29307879

RESUMO

Accounts of consent in medical ethics typically assume that consent plays the same role irrespective of the type of treatment. In this paper I argue that this assumption is false. Because of this, obligations to provide information to patients that stem from the need for consent to be valid will not apply to all types of treatment. This does not mean that there are no reasons to provide such information. The second part of the paper maps out what these reasons are and argues that they are grounded in the obligation of beneficence and a duty to warn, not in considerations of respect for autonomy.


Assuntos
Acesso à Informação , Consentimento Livre e Esclarecido , Ética Médica
12.
Br J Sports Med ; 51(9): 743-748, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27852585

RESUMO

OBJECTIVE: Fear, anxiety, depression, distress and catastrophisation are all factors known to affect pain and disability levels. To date, the association of such psychological factors has yet to be established in tendinopathy. Therefore, the purpose of this paper was to determine if psychological variables are associated with tendinopathy and whether any such variables may be associated with pain and disability outcomes in conservative management of tendinopathy. DESIGN: A systematic review was undertaken and included studies were appraised for risk of bias using the Newcastle-Ottawa Scale. Owing to heterogeneity of studies, a qualitative synthesis was undertaken. DATA SOURCES: An electronic search of MEDLINE, CiNAHL, SPORTDiscus, PsycINFO, EMBASE and PsycARTICLES was undertaken from their inception to April 2016. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Any study design that incorporated psychological measures and clinical outcomes using participants with tendinopathy. RESULTS: Ten articles describing nine studies and 1108 participants were included. Conflicting evidence exists regarding the association of anxiety, depression and lateral epicondylalgia (LE). Strong evidence suggests LE is not associated with kinesiophobia. Moderate evidence links catastrophisation and distress with LE. Moderate evidence suggests distress is not associated with rotator cuff tendinopathy, but kinesiophobia and catastrophisation are. Limited evidence suggests patellar tendinopathy is not associated with anxiety or depression and kinesiophobia may be linked with suboptimal outcomes in Achilles tendinopathy. SUMMARY/CONCLUSIONS: Tendinopathy requires an individualised approach to management. Clinicians should consider using validated screening tools for the presence of psychological variables as a part of their holistic management.


Assuntos
Dor/psicologia , Tendinopatia/psicologia , Tendão do Calcâneo/patologia , Ansiedade/psicologia , Catastrofização/psicologia , Depressão/psicologia , Humanos , Manguito Rotador/patologia , Tendinopatia/terapia , Cotovelo de Tenista/psicologia
13.
Telemed J E Health ; 23(10): 847-851, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28422614

RESUMO

OBJECTIVE: To identify potential access to telemedicine follow-up of children with clefts operated on a humanitarian mission. METHODS: A cross-sectional study of parents of children presenting to a humanitarian cleft lip and palate mission in a Provincial Hospital in the Philippines. A purpose designed questionnaire was used to assess access to electronic and digital resources that could be used to aid follow-up. Forty-five (N = 45) parents of children having primary cleft lip and or palate surgery participated. There were no interventions. Access to the Internet was through Parent Perceived Affordability of Internet Access and Parent Owned Devices. RESULTS: Thirty-one (N = 31) respondents were female. There was 93% mobile phone ownership. The mean distance traveled to the clinic was 187 km. Majority (56%) were fluent in English. Thirty-one percent accessed the Internet daily. Sixteen percent reported use of e-mail. Fifty-one percent accessed the Internet on a mobile device, and short message service use was the most affordable means of communication. CONCLUSIONS: Due to perceived unaffordability and low levels of access to devices with cameras and the Internet, as well as issues with privacy, we cannot recommend relying on electronic follow-up of patients in the developing world.


Assuntos
Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Países em Desenvolvimento/estatística & dados numéricos , Telemedicina/organização & administração , Adolescente , Adulto , Idoso , Telefone Celular/estatística & dados numéricos , Criança , Pré-Escolar , Estudos Transversais , Feminino , Acessibilidade aos Serviços de Saúde , Humanos , Internet/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Filipinas , Viagem/estatística & dados numéricos , Adulto Jovem
14.
Glob Chang Biol ; 22(5): 1880-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26730448

RESUMO

Northern peatlands have accumulated one third of the Earth's soil carbon stock since the last Ice Age. Rapid warming across northern biomes threatens to accelerate rates of peatland ecosystem respiration. Despite compensatory increases in net primary production, greater ecosystem respiration could signal the release of ancient, century- to millennia-old carbon from the peatland organic matter stock. Warming has already been shown to promote ancient peatland carbon release, but, despite the key role of vegetation in carbon dynamics, little is known about how plants influence the source of peatland ecosystem respiration. Here, we address this issue using in situ (14)C measurements of ecosystem respiration on an established peatland warming and vegetation manipulation experiment. Results show that warming of approximately 1 °C promotes respiration of ancient peatland carbon (up to 2100 years old) when dwarf-shrubs or graminoids are present, an effect not observed when only bryophytes are present. We demonstrate that warming likely promotes ancient peatland carbon release via its control over organic inputs from vascular plants. Our findings suggest that dwarf-shrubs and graminoids prime microbial decomposition of previously 'locked-up' organic matter from potentially deep in the peat profile, facilitating liberation of ancient carbon as CO2. Furthermore, such plant-induced peat respiration could contribute up to 40% of ecosystem CO2 emissions. If consistent across other subarctic and arctic ecosystems, this represents a considerable fraction of ecosystem respiration that is currently not acknowledged by global carbon cycle models. Ultimately, greater contribution of ancient carbon to ecosystem respiration may signal the loss of a previously stable peatland carbon pool, creating potential feedbacks to future climate change.


Assuntos
Ciclo do Carbono , Dióxido de Carbono/análise , Áreas Alagadas , Sequestro de Carbono , Mudança Climática , Inglaterra , Aquecimento Global
15.
J Med Ethics ; 42(6): 348-52, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27145813

RESUMO

Around the world, the population is ageing in ways that pose new challenges for healthcare providers. To date these have mostly been formulated in terms of challenges created by increasing costs, and the focus has been squarely on life-prolonging treatments. However, this focus ignores the ways in which many older people require life-enhancing treatments to counteract the effects of physical and mental decline. This paper argues that in doing so it misses important aspects of what justice requires when it comes to older people.


Assuntos
Envelhecimento , Atenção à Saúde , Alocação de Recursos , Justiça Social , Fatores Etários , Idoso , Atenção à Saúde/economia , Atenção à Saúde/ética , Humanos , Longevidade
16.
Oecologia ; 178(1): 141-51, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25687830

RESUMO

There is growing recognition that changes in vegetation composition can strongly influence peatland carbon cycling, with potential feedbacks to future climate. Nevertheless, despite accelerated climate and vegetation change in this ecosystem, the growth responses of peatland plant species to combined warming and vegetation change are unknown. Here, we used a field warming and vegetation removal experiment to test the hypothesis that dominant species from the three plant functional types present (dwarf-shrubs: Calluna vulgaris; graminoids: Eriophorum vaginatum; bryophytes: Sphagnum capillifolium) contrast in their growth responses to warming and the presence or absence of other plant functional types. Warming was accomplished using open top chambers, which raised air temperature by approximately 0.35 °C, and we measured air and soil microclimate as potential mechanisms through which both experimental factors could influence growth. We found that only Calluna growth increased with experimental warming (by 20%), whereas the presence of dwarf-shrubs and bryophytes increased growth of Sphagnum (46%) and Eriophorum (20%), respectively. Sphagnum growth was also negatively related to soil temperature, which was lower when dwarf-shrubs were present. Dwarf-shrubs may therefore promote Sphagnum growth by cooling the peat surface. Conversely, the effect of bryophyte presence on Eriophorum growth was not related to any change in microclimate, suggesting other factors play a role. In conclusion, our findings reveal contrasting abiotic and biotic controls over dominant peatland plant growth, suggesting that community composition and carbon cycling could be modified by simultaneous climate and vegetation change.


Assuntos
Biodiversidade , Ciclo do Carbono , Clima , Ecossistema , Solo , Sphagnopsida/crescimento & desenvolvimento , Temperatura , Cyperaceae/crescimento & desenvolvimento , Ericaceae/crescimento & desenvolvimento , Aquecimento Global
17.
bioRxiv ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38798440

RESUMO

Understanding the distribution of hundreds of thousands of plant metabolites across the plant kingdom presents a challenge. To address this, we curated publicly available LC-MS/MS data from 19,075 plant extracts and developed the plantMASST reference database encompassing 246 botanical families, 1,469 genera, and 2,793 species. This taxonomically focused database facilitates the exploration of plant-derived molecules using tandem mass spectrometry (MS/MS) spectra. This tool will aid in drug discovery, biosynthesis, (chemo)taxonomy, and the evolutionary ecology of herbivore interactions.

18.
Bioethics ; 27(7): 388-94, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22486227

RESUMO

There is widespread agreement that it would be both morally and legally wrong to treat a competent patient, or to carry out research with a competent participant, without the voluntary consent of that patient or research participant. Furthermore, in medical ethics it is generally taken that that consent must be informed. The most widely given reason for this has been that informed consent is needed to respect the patient's or research participant's autonomy. In this article I set out to challenge this claim by considering in detail each of the three most prominent ways in which 'autonomy' has been conceptualized in the medical ethics literature. I will argue that whilst these accounts support the claim that consent is needed if the treatment of competent patients, or research on competent individuals, is to respect their autonomy, they do not support the claim that informed consent is needed for this purpose.


Assuntos
Comportamento de Escolha , Revelação/ética , Consentimento Livre e Esclarecido/ética , Obrigações Morais , Autonomia Pessoal , Pesquisadores/ética , Sujeitos da Pesquisa , Ética Médica , Ética em Pesquisa , Humanos , Competência Mental , Sujeitos da Pesquisa/psicologia
19.
Sci Adv ; 9(35): eadi4029, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37647404

RESUMO

The metabolome is the biochemical basis of plant form and function, but we know little about its macroecological variation across the plant kingdom. Here, we used the plant functional trait concept to interpret leaf metabolome variation among 457 tropical and 339 temperate plant species. Distilling metabolite chemistry into five metabolic functional traits reveals that plants vary on two major axes of leaf metabolic specialization-a leaf chemical defense spectrum and an expression of leaf longevity. Axes are similar for tropical and temperate species, with many trait combinations being viable. However, metabolic traits vary orthogonally to life-history strategies described by widely used functional traits. The metabolome thus expands the functional trait concept by providing additional axes of metabolic specialization for examining plant form and function.


Assuntos
Longevidade , Metaboloma , Fenótipo , Folhas de Planta
20.
Elife ; 112022 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-35550673

RESUMO

Climate warming is releasing carbon from soils around the world, constituting a positive climate feedback. Warming is also causing species to expand their ranges into new ecosystems. Yet, in most ecosystems, whether range expanding species will amplify or buffer expected soil carbon loss is unknown. Here, we used two whole-community transplant experiments and a follow-up glasshouse experiment to determine whether the establishment of herbaceous lowland plants in alpine ecosystems influences soil carbon content under warming. We found that warming (transplantation to low elevation) led to a negligible decrease in alpine soil carbon content, but its effects became significant and 52% ± 31% (mean ± 95% confidence intervals) larger after lowland plants were introduced at low density into the ecosystem. We present evidence that decreases in soil carbon content likely occurred via lowland plants increasing rates of root exudation, soil microbial respiration, and CO2 release under warming. Our findings suggest that warming-induced range expansions of herbaceous plants have the potential to alter climate feedbacks from this system, and that plant range expansions among herbaceous communities may be an overlooked mediator of warming effects on carbon dynamics.


In a terrestrial ecosystem, the carbon cycle primarily represents the balance between plants consuming carbon dioxide from the atmosphere and soil microbes releasing carbon stored in the soil into the atmosphere (mostly as carbon dioxide). Given that carbon dioxide traps heat in the atmosphere, the balance of carbon inputs and outputs from an ecosystem can have important consequences for climate change. Rising temperatures caused by climate warming have led plants from lowland ecosystems to migrate uphill and start growing in alpine ecosystems, where temperatures are lower and most carbon is stored in the soil. Soil microbes use carbon stored in the soil and exuded from plants to grow, and they release this carbon ­ in the form of carbon dioxide ­ into the atmosphere through respiration. Walker et al. wanted to know how the arrival of lowland plants in alpine ecosystems under climate warming would affect carbon stores in the soil. To answer this question, Walker et al. simulated warmer temperatures by moving turfs (plants and soil) from alpine ecosystems to a warmer downhill site and planting lowland plants into the turfs. They compared the concentration of soil carbon in these turfs to that of soil in alpine turfs that had not been moved downhill and had no lowland plants. Their results showed that the warmed turfs containing lowland plants had a lower concentration of soil carbon. This suggests that climate warming will lead to more soil carbon being released into the atmosphere if lowland plants also migrate into alpine ecosystems. Walker et al. also wanted to know the mechanism through which lowland plants were decreasing soil carbon concentration under warming. They find that lowland plants probably release more small molecules into the soil than alpine plants. Soil microbes use the carbon and nutrients in these molecules to break down more complex molecules in the soil, thereby releasing nutrients and carbon that can then be used in respiration. This finding suggests that soil microbes breakdown and respire native soil carbon faster in the presence of lowland plants, releasing more carbon dioxide into the atmosphere and reducing carbon stores in the soil. Walker et al.'s results reveal a new mechanism through which uphill migration of lowland plants could increase the effects of climate change, in a feedback loop. Further research as to whether this mechanism occurs in different regions and ecosystems could help to quantify the magnitude of this feedback and allow scientists to make more accurate predictions about climate change.


Assuntos
Ecossistema , Solo , Carbono , Mudança Climática , Plantas , Microbiologia do Solo
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