77 research outputs found

    Functional traits and water transport strategies in lowland tropical rainforest trees

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    © 2015 Apgaua et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Understanding how tropical rainforest trees may respond to the precipitation extremes predicted in future climate change scenarios is paramount for their conservation and management. Tree species clearly differ in drought susceptibility, suggesting that variable water transport strategies exist. Using a multi-disciplinary approach, we examined the hydraulic variability in trees in a lowland tropical rainforest in north-eastern Australia. We studied eight tree species representing broad plant functional groups (one palm and seven eudicot mature-phase, and early-successional trees). We characterised the species' hydraulic system through maximum rates of volumetric sap flow and velocities using the heat ratio method, and measured rates of tree growth and several stem, vessel, and leaf traits. Sap flow measures exhibited limited variability across species, although early-successional species and palms had high mean sap velocities relative to most mature-phase species. Stem, vessel, and leaf traits were poor predictors of sap flow measures. However, these traits exhibited different associations in multivariate analysis, revealing gradients in some traits across species and alternative hydraulic strategies in others. Trait differences across and within tree functional groups reflect variation in water transport and drought resistance strategies. These varying strategies will help in our understanding of changing species distributions under predicted drought scenarios

    Treatment for hepatorenal syndrome in people with decompensated liver cirrhosis: a network meta‐analysis

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    Background: Hepatorenal syndrome is defined as renal failure in people with cirrhosis in the absence of other causes. In addition to supportive treatment such as albumin to restore fluid balance, the other potential treatments include systemic vasoconstrictor drugs (such as vasopressin analogues or noradrenaline), renal vasodilator drugs (such as dopamine), transjugular intrahepatic portosystemic shunt (TIPS), and liver support with molecular adsorbent recirculating system (MARS). There is uncertainty over the best treatment regimen for hepatorenal syndrome. Objectives: To compare the benefits and harms of different treatments for hepatorenal syndrome in people with decompensated liver cirrhosis. Search methods: We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and trial registers until December 2018 to identify randomised clinical trials on hepatorenal syndrome in people with cirrhosis. Selection criteria: We included only randomised clinical trials (irrespective of language, blinding, or publication status) in adults with cirrhosis and hepatorenal syndrome. We excluded randomised clinical trials in which participants had previously undergone liver transplantation. Data collection and analysis: Two authors independently identified eligible trials and collected data. The outcomes for this review included mortality, serious adverse events, any adverse events, resolution of hepatorenal syndrome, liver transplantation, and other decompensation events. We performed a network meta‐analysis with OpenBUGS using Bayesian methods and calculated the odds ratio (OR), rate ratio, hazard ratio (HR), and mean difference (MD) with 95% credible intervals (CrI) based on an available‐case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance. Main results: We included a total of 25 trials (1263 participants; 12 interventions) in the review. Twenty‐three trials (1185 participants) were included in one or more outcomes. All the trials were at high risk of bias, and all the evidence was of low or very low certainty. The trials included participants with liver cirrhosis of varied aetiologies as well as a mixture of type I hepatorenal syndrome only, type II hepatorenal syndrome only, or people with both type I and type II hepatorenal syndrome. Participant age ranged from 42 to 60 years, and the proportion of females ranged from 5.8% to 61.5% in the trials that reported this information. The follow‐up in the trials ranged from one week to six months. Overall, 59% of participants died during this period and about 35% of participants recovered from hepatorenal syndrome. The most common interventions compared were albumin plus terlipressin, albumin plus noradrenaline, and albumin alone. There was no evidence of a difference in mortality (22 trials; 1153 participants) at maximal follow‐up between the different interventions. None of the trials reported health‐related quality of life. There was no evidence of differences in the proportion of people with serious adverse events (three trials; 428 participants), number of participants with serious adverse events per participant (two trials; 166 participants), proportion of participants with any adverse events (four trials; 402 participants), the proportion of people who underwent liver transplantation at maximal follow‐up (four trials; 342 participants), or other features of decompensation at maximal follow‐up (one trial; 466 participants). Five trials (293 participants) reported number of any adverse events, and five trials (219 participants) reported treatment costs. Albumin plus noradrenaline had fewer numbers of adverse events per participant (rate ratio 0.51, 95% CrI 0.28 to 0.87). Eighteen trials (1047 participants) reported recovery from hepatorenal syndrome (as per definition of hepatorenal syndrome). In terms of recovery from hepatorenal syndrome, in the direct comparisons, albumin plus midodrine plus octreotide and albumin plus octreotide had lower recovery from hepatorenal syndrome than albumin plus terlipressin (HR 0.04; 95% CrI 0.00 to 0.25 and HR 0.26, 95% CrI 0.07 to 0.80 respectively). There was no evidence of differences between the groups in any of the other direct comparisons. In the network meta‐analysis, albumin and albumin plus midodrine plus octreotide had lower recovery from hepatorenal syndrome compared with albumin plus terlipressin. Funding: two trials were funded by pharmaceutical companies; five trials were funded by parties who had no vested interest in the results of the trial; and 18 trials did not report the source of funding. Authors' conclusions: Based on very low‐certainty evidence, there is no evidence of benefit or harm of any of the interventions for hepatorenal syndrome with regards to the following outcomes: all‐cause mortality, serious adverse events (proportion), number of serious adverse events per participant, any adverse events (proportion), liver transplantation, or other decompensation events. Low‐certainty evidence suggests that albumin plus noradrenaline had fewer 'any adverse events per participant' than albumin plus terlipressin. Low‐ or very low‐certainty evidence also found that albumin plus midodrine plus octreotide and albumin alone had lower recovery from hepatorenal syndrome compared with albumin plus terlipressin. Future randomised clinical trials should be adequately powered; employ blinding, avoid post‐randomisation dropouts or planned cross‐overs (or perform an intention‐to‐treat analysis); and report clinically important outcomes such as mortality, health‐related quality of life, adverse events, and recovery from hepatorenal syndrome. Albumin plus noradrenaline and albumin plus terlipressin appear to be the interventions that should be compared in future trials

    TRY plant trait database - enhanced coverage and open access

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    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    TRY plant trait database - enhanced coverage and open access

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    This article has 730 authors, of which I have only listed the lead author and myself as a representative of University of HelsinkiPlant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.Peer reviewe

    TRY plant trait database – enhanced coverage and open access

    Get PDF
    Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    TRY plant trait database - enhanced coverage and open access

    Get PDF
    Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    TRY plant trait database – enhanced coverage and open access

    Get PDF
    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    AusTraits, a curated plant trait database for the Australian flora

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    We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge
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