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1.
Glob Chang Biol ; 30(4): e17280, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38613249

RESUMO

Coastal wetlands play an important role in regulating atmospheric carbon dioxide (CO2) concentrations and contribute significantly to climate change mitigation. However, climate change, reclamation, and restoration have been causing substantial changes in coastal wetland areas and carbon exchange in China during recent decades. Here we compiled a carbon flux database consisting of 15 coastal wetland sites to assess the magnitude, patterns, and drivers of carbon fluxes and to compare fluxes among contrasting natural, disturbed, and restored wetlands. The natural coastal wetlands have the average net ecosystem exchange of CO2 (NEE) of -577 g C m-2 year-1, with -821 g C m-2 year-1 for mangrove forests and -430 g C m-2 year-1 for salt marshes. There are pronounced latitudinal patterns for carbon dioxide exchange of natural coastal wetlands: NEE increased whereas gross primary production (GPP) and respiration of ecosystem decreased with increasing latitude. Distinct environmental factors drive annual variations of GPP between mangroves and salt marshes; temperature was the dominant controlling factor in salt marshes, while temperature, precipitation, and solar radiation were co-dominant in mangroves. Meanwhile, both anthropogenic reclamation and restoration had substantial effects on coastal wetland carbon fluxes, and the effect of the anthropogenic perturbation in mangroves was more extensive than that in salt marshes. Furthermore, from 1980 to 2020, anthropogenic reclamation of China's coastal wetlands caused a carbon loss of ~3720 Gg C, while the mangrove restoration project during the period of 2021-2025 may switch restored coastal wetlands from a carbon source to carbon sink with a net carbon gain of 73 Gg C. The comparison of carbon fluxes among these coastal wetlands can improve our understanding of how anthropogenic perturbation can affect the potentials of coastal blue carbon in China, which has implications for informing conservation and restoration strategies and efforts of coastal wetlands.


Assuntos
Ecossistema , Áreas Alagadas , Dióxido de Carbono , Ciclo do Carbono , China
2.
J Theor Biol ; 529: 110857, 2021 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-34384836

RESUMO

In natural forests at a demographic equilibrium state, the size frequency distribution (SFD) of trees is linked with their size-dependent growth and mortality rates. While the mean growth rate (MGR) of each size class is generally used for determining the SFD, the variance in the growth rate (VGR) has always been ignored. Here, based on the analyses with Kolmogorov forward equation, we show that in general, the VGR can flatten the slope of the SFD and, in particular, can address the contradiction between the size-dependent MGR and the -2 power-law SFD in the metabolic scaling theory. We traced the origin of the VGR to the intrinsic stochasticity in the allometric growth coefficients of trees and deduced its functional form based on variance propagation. Using the forest censuses data from Barro Colorado Island, we verified the prediction of the VGR and indicated its indispensability in the theory of forest size-structure formation.


Assuntos
Florestas , Árvores
3.
New Phytol ; 221(1): 155-168, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30272817

RESUMO

Plant functional ecology requires the quantification of trait variation and its controls. Field measurements on 483 species at 48 sites across China were used to analyse variation in leaf traits, and assess their predictability. Principal components analysis (PCA) was used to characterize trait variation, redundancy analysis (RDA) to reveal climate effects, and RDA with variance partitioning to estimate separate and overlapping effects of site, climate, life-form and family membership. Four orthogonal dimensions of total trait variation were identified: leaf area (LA), internal-to-ambient CO2 ratio (χ), leaf economics spectrum traits (specific leaf area (SLA) versus leaf dry matter content (LDMC) and nitrogen per area (Narea )), and photosynthetic capacities (Vcmax , Jmax at 25°C). LA and χ covaried with moisture index. Site, climate, life form and family together explained 70% of trait variance. Families accounted for 17%, and climate and families together 29%. LDMC and SLA showed the largest family effects. Independent life-form effects were small. Climate influences trait variation in part by selection for different life forms and families. Trait values derived from climate data via RDA showed substantial predictive power for trait values in the available global data sets. Systematic trait data collection across all climates and biomes is still necessary.


Assuntos
Folhas de Planta/fisiologia , China , Clima , Ecossistema , Nitrogênio/metabolismo , Fotossíntese , Folhas de Planta/anatomia & histologia , Análise de Componente Principal
4.
Plant Cell Environ ; 41(12): 2744-2757, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29996176

RESUMO

Anatomical adaptations to high-salinity environments in mangrove leaves may be recorded in leaf water isotopes. Recent studies observed lower 18 O enrichment (ΔL ) of leaf water with respect to source water in three mangrove species relative to adjacent freshwater trees, but the factors that govern this phenomenon remain unclear. To resolve this issue, we investigated leaf traits and ΔL in 15 species of true mangrove plants, 14 species of adjacent freshwater trees, and 4 species of semi-mangrove plants at five study sites along south-eastern coast of China. Our results confirm that ΔL was generally 3-4‰ lower for mangrove species than for adjacent freshwater or semi-mangrove species. We hypothesized that higher leaf water content (LWC) and lower leaf stomatal density (LS) both played important roles in reducing ΔL in mangroves relative to nearby freshwater plants. Both differences acted to elongate effective leaf mixing length (L) in mangroves by about 200% and lower stomatal conductance by about 30%. Péclet models based on both LWC and LS could accurately predict ΔL . Our findings highlight the potential species-specific anatomical determinants of ΔL (or L), which has important implications for the interpretation of environmental information from metabolites produced by leaf water isotopes in palaeoclimate research.


Assuntos
Folhas de Planta/anatomia & histologia , Plantas Tolerantes a Sal/anatomia & histologia , China , Isótopos de Oxigênio/metabolismo , Folhas de Planta/metabolismo , Estômatos de Plantas/anatomia & histologia , Estômatos de Plantas/metabolismo , Transpiração Vegetal , Plantas Tolerantes a Sal/metabolismo , Água/metabolismo , Áreas Alagadas
5.
J Theor Biol ; 452: 17-21, 2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-29752952

RESUMO

Scaling relations formed in forest development processes are fairly important for understanding and predicting forest dynamics. During self-thinning of a relatively even-sized forest, tree abundance will decrease with an increase in average tree size, forming the size-abundance relation (SAR); while for a size-structured forest under the demographic equilibrium state, the frequency of trees also varies with size classes in a similar, decreasing pattern, manifesting as the size-frequency distribution (SFD). In the metabolic scaling theory (MST), the two scaling relations are considered to be consistent. However, in this paper, we proved that SFD can never be equivalent to SAR unless the growth rate of tree diameters is a constant. The reason derives from the time differences of transition between different size classes, which are influenced in SFD maintenance but not in SAR formation. Demographic equilibrium of a size structured forest requires a different resource allocation among different size classes at the same time, which contradicts the resource conservation during SAR formation in the self-thinning process. Consequently, if the rate of resource use per individual scales as a +2 power with its diameter according to MST, which led to the -2 power SAR, SFD can never be a -2 power-law distribution. The previous confusion between SFD of a size-structured forest and SAR formed during self-thinning processes may lead to many misunderstandings and unreliable predictions on forest structure and dynamics.


Assuntos
Algoritmos , Ecossistema , Florestas , Modelos Biológicos , Árvores/crescimento & desenvolvimento , Biomassa , Dinâmica Populacional , Árvores/classificação , Árvores/metabolismo
6.
Glob Chang Biol ; 23(3): 1180-1198, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27400026

RESUMO

Wetlands play an important role in regulating the atmospheric carbon dioxide (CO2 ) concentrations and thus affecting the climate. However, there is still lack of quantitative evaluation of such a role across different wetland types, especially at the global scale. Here, we conducted a meta-analysis to compare ecosystem CO2 fluxes among various types of wetlands using a global database compiled from the literature. This database consists of 143 site-years of eddy covariance data from 22 inland wetland and 21 coastal wetland sites across the globe. Coastal wetlands had higher annual gross primary productivity (GPP), ecosystem respiration (Re ), and net ecosystem productivity (NEP) than inland wetlands. On a per unit area basis, coastal wetlands provided large CO2 sinks, while inland wetlands provided small CO2 sinks or were nearly CO2 neutral. The annual CO2 sink strength was 93.15 and 208.37 g C m-2 for inland and coastal wetlands, respectively. Annual CO2 fluxes were mainly regulated by mean annual temperature (MAT) and mean annual precipitation (MAP). For coastal and inland wetlands combined, MAT and MAP explained 71%, 54%, and 57% of the variations in GPP, Re , and NEP, respectively. The CO2 fluxes of wetlands were also related to leaf area index (LAI). The CO2 fluxes also varied with water table depth (WTD), although the effects of WTD were not statistically significant. NEP was jointly determined by GPP and Re for both inland and coastal wetlands. However, the NEP/Re and NEP/GPP ratios exhibited little variability for inland wetlands and decreased for coastal wetlands with increasing latitude. The contrasting of CO2 fluxes between inland and coastal wetlands globally can improve our understanding of the roles of wetlands in the global C cycle. Our results also have implications for informing wetland management and climate change policymaking, for example, the efforts being made by international organizations and enterprises to restore coastal wetlands for enhancing blue carbon sinks.


Assuntos
Mudança Climática , Ecossistema , Áreas Alagadas , Dióxido de Carbono , Clima
7.
Glob Chang Biol ; 23(11): 4706-4716, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28418083

RESUMO

Methane (CH4 ) emissions from tropical wetlands contribute 60%-80% of global natural wetland CH4 emissions. Decreased wetland CH4 emissions can act as a negative feedback mechanism for future climate warming and vice versa. The impact of the El Niño-Southern Oscillation (ENSO) on CH4 emissions from wetlands remains poorly quantified at both regional and global scales, and El Niño events are expected to become more severe based on climate models' projections. We use a process-based model of global wetland CH4 emissions to investigate the impacts of the ENSO on CH4 emissions in tropical wetlands for the period from 1950 to 2012. The results show that CH4 emissions from tropical wetlands respond strongly to repeated ENSO events, with negative anomalies occurring during El Niño periods and with positive anomalies occurring during La Niña periods. An approximately 8-month time lag was detected between tropical wetland CH4 emissions and ENSO events, which was caused by the combined time lag effects of ENSO events on precipitation and temperature over tropical wetlands. The ENSO can explain 49% of interannual variations for tropical wetland CH4 emissions. Furthermore, relative to neutral years, changes in temperature have much stronger effects on tropical wetland CH4 emissions than the changes in precipitation during ENSO periods. The occurrence of several El Niño events contributed to a lower decadal mean growth rate in atmospheric CH4 concentrations throughout the 1980s and 1990s and to stable atmospheric CH4 concentrations from 1999 to 2006, resulting in negative feedback to global warming.


Assuntos
Mudança Climática , El Niño Oscilação Sul , Gases de Efeito Estufa/análise , Metano/análise , Áreas Alagadas , Monitoramento Ambiental , Aquecimento Global , Modelos Teóricos , Estações do Ano
8.
Biol Lett ; 13(1)2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28052938

RESUMO

Mangroves in China are severely affected by the rapid invasion of the non-native species Spartina alterniflora Although many studies have addressed the possible impacts of S. alterniflora on the performance of mangrove seedlings, how excessive nitrogen (N) input due to eutrophication affects the interactions between mangrove species and S. alterniflora remains unknown. Here, we report the results from a mesocosm experiment using seedlings of the native mangrove species Kandelia obovata and the exotic S. alterniflora grown in monoculture and mixed culture under no nitrogen addition and nitrogen (N) addition treatments for 18 months. Without N addition, the presence of S. alterniflora inhibited the growth of K. obovata seedlings. Excessive N addition significantly increased the growth rate of K. obovata in both cultures. However, the positive and significantly increasing relative interaction intensity index under excessive N input suggested that the invasion of S. alterniflora could favour the growth of K. obovata under eutrophication conditions. Our results imply that excessive N input in southeastern China can increase the competitive ability of mangrove seedlings against invasive S. alterniflora.


Assuntos
Nitrogênio , Poaceae/crescimento & desenvolvimento , Rhizophoraceae/crescimento & desenvolvimento , China , Espécies Introduzidas , Nitrogênio/farmacologia , Poaceae/efeitos dos fármacos , Rhizophoraceae/efeitos dos fármacos , Água do Mar/química , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Áreas Alagadas
9.
Curr Microbiol ; 74(1): 68-76, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27807655

RESUMO

Marine algae provide a unique niche termed the phycosphere for microorganism inhabitation. The phycosphere environment is an important niche for mutualistic and competitive interactions between algae and bacteria. Quorum sensing (QS) serves as a gene regulatory system in the microbial biosphere that allows bacteria to sense the population density with signaling molecules, such as acyl-homoserine lactone (AHL), and adapt their physiological activities to their surroundings. Understanding the QS system is important to elucidate the interactions between algal-associated microbial communities in the phycosphere condition. In this study, we isolated an epidermal bacterium (ST2) from the marine dinoflagellate Scrippsiella trochoidea and evaluated its AHL production profile. Strain ST2 was classified as a member of the genus Citrobacter closely related to Citrobacter freundii by 16S rRNA gene sequence analysis. Thin-layer chromatography revealed that C. freundii ST2 secreted three active AHL compounds into the culture supernatant. Specific compounds, such as N-butyryl-L-homoserine lactone (C4-AHL), N-octanoyl-DL-homoserine lactone (C8-AHL), and N-decanoyl-DL-homoserine lactone (C10-AHL), were identified by high-resolution tandem mass spectrometry. Carbon metabolic profiling with Biolog EcoPlate™ indicated that C. freundii ST2 was widely used as a carbon source and preferred carbohydrates, amino acids, and carboxylic acids as carbon substrates. Our results demonstrated that C. freundii ST2 is a multi-AHL producer that participates in the phycosphere carbon cycle.


Assuntos
4-Butirolactona/análogos & derivados , Citrobacter freundii/isolamento & purificação , Citrobacter freundii/metabolismo , Dinoflagellida/microbiologia , 4-Butirolactona/química , 4-Butirolactona/metabolismo , Citrobacter freundii/classificação , Citrobacter freundii/genética , Filogenia , Água do Mar/microbiologia , Água do Mar/parasitologia
10.
ScientificWorldJournal ; 2014: 943697, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25133267

RESUMO

The eddy flux data with field records of tidal water inundation depths of the year 2010 from two mangroves forests in southern China were analyzed to investigate the tidal effect on mangrove carbon cycle. We compared the net ecosystem exchange (NEE) and its responses to light and temperature, respectively, between spring tide and neap tide inundation periods. For the most time of the year 2010, higher daytime NEE values were found during spring tides than during neap tides at both study sites. Regression analysis of daytime NEE to photosynthetically active radiation (PAR) using the Landsberg model showed increased sensitivity of NEE to PAR with higher maximum photosynthetic rate during spring tides than neap tides. In contrast, the light compensation points acquired from the regression function of the Landsberg model were smaller during spring tides than neap tides in most months. The dependence of nighttime NEE on soil temperature was lower under spring tide than under neap tides. All these results above indicated that ecosystem carbon uptake rates of mangrove forests were strengthened, while ecosystem respirations were inhibited during spring tides in comparison with those during neap tides, which needs to be considered in modeling mangrove ecosystem carbon cycle under future sea level rise scenarios.


Assuntos
Pegada de Carbono , Florestas , Luz , Estações do Ano , Temperatura , Ondas de Maré , Áreas Alagadas , Modelos Biológicos , Rhizophoraceae/fisiologia , Clima Tropical
11.
Water Res ; 258: 121821, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38796913

RESUMO

Phosphorus affects microbial metabolic activity, nitrogen and carbon cycling in mangrove sediment, but its influence on carbon stability and greenhouse gases emission remains unclear. This study compared greenhouse gases (CO2, N2O, and CH4) emissions from mangrove sediment receiving wastewater containing various phosphorus concentrations, and evaluated its long term effect on sediment carbon flux when phosphorus pollution is eliminated. Significant increases in greenhouse gases flux and decrease of total organic carbon and readily oxidizable organic carbon in the sediment were observed after phosphorus discharge. Specifically, the N2O flux was reduced significantly at high phosphorus levels while the CO2 flux and the microbial biomass organic carbon was increased. The copy numbers of ammonia oxidation (AOA-amoA, AOB-amoA) gene, denitrification (narG, nirK) gene and methanogenesis (mcrA) gene increased with the increasing phosphorus concentration. During the wastewater discharge period for 70 days, the global warming potential of sediment flux at high phosphorus discharge condition was more than 4 times that of the control group, and the loss of total organic carbon and readily oxidizable organic carbon was 4.66 % and 7.1 %, respectively. During the remediation period (71-101 days), the greenhouse gases flux decreased rapidly, ends up with a similar level of the control group. Our results indicate that using mangrove wetland for pollution minimization in the coastal aquaculture industry could increase greenhouse gases emisison significantly, it is therefore essential to reduce phosphorus discharges from various anthropogenic activities, and local authorities must set up more stringent discharge standards in the future.


Assuntos
Fósforo , Áreas Alagadas , Sedimentos Geológicos/química , Águas Residuárias/química , Carbono
12.
Appl Microbiol Biotechnol ; 97(15): 7035-48, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23135227

RESUMO

Mangroves are unique and highly productive ecosystems and harbor very special microbial communities. Although the phylogenetic diversity of sediment microbial communities of mangrove habitats has been examined extensively, little is known regarding their functional gene diversity and metabolic potential. In this study, a high-throughput functional gene array (GeoChip 4.0) was used to analyze the functional diversity, composition, structure, and metabolic potential of microbial communities in mangrove habitats from mangrove national nature reserves in China. GeoChip data indicated that these microbial communities were functionally diverse as measured by the number of genes detected, unique genes, and various diversity indices. Almost all key functional gene categories targeted by GeoChip 4.0 were detected in the mangrove microbial communities, including carbon (C) fixation, C degradation, methane generation, nitrogen (N) fixation, nitrification, denitrification, ammonification, N reduction, sulfur (S) metabolism, metal resistance, antibiotic resistance, and organic contaminant degradation. Detrended correspondence analysis (DCA) of all detected genes showed that Spartina alterniflora (HH), an invasive species, did not harbor significantly different microbial communities from Aegiceras corniculatum (THY), a native species, but did differ from other species, Kenaelia candel (QQ), Aricennia marina (BGR), and mangrove-free mud flat (GT). Canonical correspondence analysis (CCA) results indicated the microbial community structure was largely shaped by surrounding environmental variables, such as total nitrogen (TN), total carbon (TC), pH, C/N ratio, and especially salinity. This study presents a comprehensive survey of functional gene diversity of soil microbial communities from different mangrove habitats/species and provides new insights into our understanding of the functional potential of microbial communities in mangrove ecosystems.


Assuntos
Bactérias/genética , Variação Genética , Rhizophoraceae/microbiologia , Microbiologia do Solo , Bactérias/classificação , Bactérias/metabolismo , Carbono/metabolismo , DNA Bacteriano/genética , Nitrogênio/metabolismo , Fósforo/metabolismo , Enxofre/metabolismo
13.
Water Sci Technol ; 67(3): 572-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23202562

RESUMO

The decoloration of an azo dye reactive brilliant orange (X-GN) by a heterogeneous Fenton system using activated carbon-FeOOH catalyst (AC-FeOOH) and H(2)O(2) was studied. Under typical conditions (pH 7.0, H(2)O(2) 10 mmol/L, AC-FeOOH 1.0 g/L and 30 °C), 98% decoloration rate of X-GN was achieved in 240 min. The decoloration efficiency of X-GN increased with higher H(2)O(2) dosage, higher AC-FeOOH dosage and higher reaction temperature. Though the catalytic reaction was an acid driven process, a sufficient decoloration performance was still obtained in neutral and alkaline conditions. Kinetic studies suggested that the decoloration of X-GN followed a pseudo-first order reaction and the activation energy was 17.2 kJ/mol. Iron leaching from AC-FeOOH occurred during the reaction, but the decoloration efficiency of X-GN was still higher than 80% after four runs. The AC-FeOOH has a good stability and can be reused. Besides, the generation of massive iron-containing sludge can be avoided after reaction as the remaining ferric ions in the solution were less than 1 mg/L in this combined H(2)O(2) and AC-FeOOH process.


Assuntos
Compostos Azo/química , Peróxido de Hidrogênio/química , Ferro/química , Eliminação de Resíduos Líquidos/métodos , Catálise , Concentração de Íons de Hidrogênio
14.
J Oncol ; 2023: 8161683, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36880008

RESUMO

Objective: To investigate the efficacy of recombinant human endostatin (rh-Endo) plus neoadjuvant chemotherapy (NACT) for osteosarcoma (OSA) and its influence on serum vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9). Methods: The case data of 141 OSA patients presented to the North District, Xiangyang Central Hospital Affiliated to Hubei University of Arts and Sciences from January 2018 to June 2019, were analyzed retrospectively. Patients receiving NACT (methotrexate + ifosfamide + adriamycin) were assigned into the control group (CNG; n = 65), while those treated with rh-Endo plus NACT were included in the combination group (CMG; n = 76). The following aspects were compared: clinical efficacy, serum tumor markers, serum VEGF and MMP-9 contents, inflammatory factors, incidence of adverse reactions, limb function scores at 6 months of follow-up, and prognostic quality of life (QOL). Results: A statistically higher overall response rate (ORR) was determined in CMG versus CNG (84.2% vs. 64.6%, P < 0.05). The pretreatment serum bone alkaline phosphatase (BALP), insulin-like growth factor (IGF)-1, serum amyloid A (SAA), VEGF, MMP-9, C-reactive protein (CRP), tumor necrosis factor (TNF)-α, and interleukin (IL)-10 levels differed insignificantly between the two cohorts (P > 0.05); while except IL-10 that showed increased expression in both cohorts and was comparatively higher in CMG, the other 8 parameters reduced in both cohorts after 2 weeks of drug withdrawal, and the reduction of each parameter was more significant in CMG (P < 0.05). The total adverse reaction rate was 30.2% in CMG, which was higher than that of 36.9% in CNG, albeit without a statistical difference (P > 0.05). An evidently higher 2-year survival rate was determined in CMG (P < 0.05). Conclusions: rh-Endo plus NACT is more effective than NACT alone in the treatment of osteosarcoma, which can validly restore the balance of vascular endothelial cells, reduce inflammation, and is worth promoting in clinic.

15.
J Agric Food Chem ; 71(37): 13662-13671, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37668543

RESUMO

A study of different grapevine tissues and organs (root, stem, leaf, fruit) water isotope fractionation models from high-quality wine grapes produced in the Helan Mountains, a key wine-producing area in northwestern China, was undertaken. Results showed that δ2H values of local groundwater sources were more negative than rivers and precipitation. Soil water δ2H and δ18O values were significantly higher than those of other environmental water sources. Water from the soil surface layer (0-30 cm, δ2H and δ18O values) was more positive than the deeper layer (30-60 cm), indicating that soil water has undergone a positive fractionation effect. δ2H and δ18O values of tissues and organs from different grape varieties followed a similar pattern but were more negative than the local atmospheric precipitation line (slope between 4.1 to 5.2). The 2H and 18O fractionation relationship in grapevine organs was similar, and 18O has a higher fractionation effect than 2H. δ2H and δ18O values showed a strong fractionation effect during the transportation of water to different grape organs (trend of stem > fruit > leaf). This study showed that 18/16O fractionation in grapes is more likely to occur under drought conditions and provides a theoretical basis to improve traceability accuracy and origin protection of wine production areas.


Assuntos
Vitis , Isótopos de Oxigênio , Hidrogênio , Secas , Solo , Água
16.
Nat Commun ; 14(1): 756, 2023 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-36765059

RESUMO

Significant efforts have been invested to restore mangrove forests worldwide through reforestation and afforestation. However, blue carbon benefit has not been compared between these two silvicultural pathways at the global scale. Here, we integrated results from direct field measurements of over 370 restoration sites around the world to show that mangrove reforestation (reestablishing mangroves where they previously colonized) had a greater carbon storage potential per hectare than afforestation (establishing mangroves where not previously mangrove). Greater carbon accumulation was mainly attributed to favorable intertidal positioning, higher nitrogen availability, and lower salinity at most reforestation sites. Reforestation of all physically feasible areas in the deforested mangrove regions of the world could promote the uptake of 671.5-688.8 Tg CO2-eq globally over a 40-year period, 60% more than afforesting the same global area on tidal flats (more marginal sites). Along with avoiding conflicts of habitat conversion, mangrove reforestation should be given priority when designing nature-based solutions for mitigating global climate change.


Assuntos
Mudança Climática , Áreas Alagadas , Carbono , Ecossistema , Florestas
17.
Innovation (Camb) ; 4(5): 100481, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37636281

RESUMO

To achieve the Paris Agreement, China pledged to become "Carbon Neutral" by the 2060s. In addition to massive decarbonization, this would require significant changes in ecosystems toward negative CO2 emissions. The ability of coastal blue carbon ecosystems (BCEs), including mangrove, salt marsh, and seagrass meadows, to sequester large amounts of CO2 makes their conservation and restoration an important "nature-based solution (NbS)" for climate adaptation and mitigation. In this review, we examine how BCEs in China can contribute to climate mitigation. On the national scale, the BCEs in China store up to 118 Tg C across a total area of 1,440,377 ha, including over 75% as unvegetated tidal flats. The annual sedimental C burial of these BCEs reaches up to 2.06 Tg C year-1, of which most occurs in salt marshes and tidal flats. The lateral C flux of mangroves and salt marshes contributes to 1.17 Tg C year-1 along the Chinese coastline. Conservation and restoration of BCEs benefit climate change mitigation and provide other ecological services with a value of $32,000 ha-1 year-1. The potential practices and technologies that can be implemented in China to improve BCE C sequestration, including their constraints and feasibility, are also outlined. Future directions are suggested to improve blue carbon estimates on aerial extent, carbon stocks, sequestration, and mitigation potential. Restoring and preserving BCEs would be a cost-effective step to achieve Carbon Neutral by 2060 in China despite various barriers that should be removed.

18.
Clin Rheumatol ; 42(9): 2353-2367, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37311918

RESUMO

OBJECTIVES: This study aims to compare the differences among patients of different onset ages in various subtypes of lupus erythematosus (LE) and to draw a panorama of the clinical characteristics of patients with different onset ages. METHOD: Subjects were recruited from the Lupus Erythematosus Multicenter Case-control Study in Chinese populations (LEMCSC), grouped by the age of onset (childhood-onset: onset < 18 years, adult-onset: onset 18-50 years, late-onset: onset > 50 years). The data collected included demographic characteristics, LE-related systemic involvement, LE-related mucocutaneous manifestations, and laboratory results. All included patients were assigned into three groups: systemic LE (SLE) group (with systemic involvement, with or without mucocutaneous lesions), cutaneous LE (CLE) group (patients who were accompanied by any type of LE-specific cutaneous manifestations), and isolated cutaneous LE (iCLE) group (patients who were in CLE group without systemic involvements). Data were analyzed using R version 4.0.3. RESULTS: A total of 2097 patients were involved, including 1865 with SLE and 232 with iCLE. We also identified 1648 patients with CLE among them, as there was some overlap between the SLE population and CLE population (patients with SLE and LE-specific cutaneous manifestations). Later-onset lupus patients seemed to be less female predominance (p < 0.001) and have less systemic involvement (except arthritis), lower positive rates of autoimmune antibodies, less ACLE, and more DLE. Moreover, childhood-onset SLE patients presented a higher risk of LE family history (p = 0.002, vs adult-onset SLE). In contrast to other LE-nonspecific manifestations, the self-reported photosensitivity history decreased with the age of onset in SLE patients (51.8%, 43.4%, and 39.1%, respectively) but increased in iCLE patients (42.4%, 64.9%, and 89.2%, respectively). There was also a gradual increase in self-reported photosensitivity from SLE, CLE, to iCLE in both adult-onset and late-onset lupus patients. CONCLUSIONS: A negative correlation was suggested between the age of onset and the likelihood of systemic involvement, except for arthritis. As the age of onset increases, patients have a greater propensity to exhibit DLE compared to ACLE. Moreover, the presence of rapid response photodermatitis (i.e., self-reported photosensitivity) was associated with a lower rate of systemic involvement. TRIAL REGISTRATION: This study was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR2100048939) on July 19, 2021, retrospectively registered. Key Points • We confirmed some phenomena that have been found in patients with SLE, such as the highest proportion of females of reproductive age, the higher risk of LE family history in childhood-onset SLE patients, and the less self-reported photosensitivity in the late-onset SLE group. We also compared the similarities and differences of these phenomena in patients with CLE or iCLE for the first time. • In patients with SLE, the proportion of females peaked in adult-onset patients, but this phenomenon disappeared in iCLE patients: the female-male ratio tends to decrease from childhood-onset iCLE, adult-onset iCLE, to late-onset iCLE. • Patients with early-onset lupus are more likely to have acute cutaneous lupus erythematosus (ACLE), and patients with late-onset lupus are more likely to have discoid lupus erythematosus (DLE). • In contrast to other LE-nonspecific manifestations, the incidence of rapid response photodermatitis (i.e., self-reported photosensitivity) decreased with the age of onset in SLE patients but increased with the age of onset in iCLE patients.


Assuntos
Artrite , Lúpus Eritematoso Cutâneo , Lúpus Eritematoso Discoide , Lúpus Eritematoso Sistêmico , Transtornos de Fotossensibilidade , Adulto , Humanos , Masculino , Feminino , Adolescente , Idade de Início , Estudos Transversais , Estudos de Casos e Controles , Lúpus Eritematoso Discoide/complicações , Lúpus Eritematoso Discoide/patologia , Transtornos de Fotossensibilidade/complicações , Transtornos de Fotossensibilidade/epidemiologia , Lúpus Eritematoso Sistêmico/epidemiologia , Lúpus Eritematoso Sistêmico/complicações , Artrite/complicações , Doença Aguda , China/epidemiologia
19.
Ecology ; 93(3): 588-97, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22624213

RESUMO

Cordgrass (Spartina alterniflora) was introduced to China in 1979 from the United States for reducing coastal erosion. It grows vigorously in China and has spread over much of the Chinese coast, from Leizhou Peninsula to Liaoning, a range of more than 19 degrees of latitude. On the southern coast of China, S. alterniflora has invaded mangrove-dominated habitats during the last two decades, but little is known about interactions between native mangroves and invasive S. alterniflora. We studied the distribution and competitive interactions between native mangroves and S. alterniflora in the Zhangjiang Estuary at four tidal sites along a salinity gradient: oligohaline upstream, mesohaline, polyhaline, and euhaline downstream. S. alterniflora occurred at all four sites, and several mangrove species occurred at all but the downstream euhaline site. S. alterniflora has invaded the estuary widely and has spread to the lower tidal margins of mangroves. It has not invaded mangrove areas with a closed canopy but has established in the mangrove zone where the canopy was opened by human disturbance. Ramets of S. alterniflora transplanted into the understory of mangrove stands with closed canopies died within 10 weeks, but 37.5% survived and grew well on open mud flats. S. alterniflora had virtually no competitive effect on mangrove seedlings planted at the upstream oligohaline site. However, S. alterniflora competitively reduced biomass of mangrove seedlings to 33% over a period of 14 weeks at the mesohaline and polyhaline sites where human disturbance has opened the mangrove canopy. In contrast, S. alterniflora marginally facilitated growth and survival of experimental seedlings at the downstream euhaline site. In China, mangroves occur along the coastline south of Whenzhou, but they have been severely disturbed and removed widely, mainly by mariculture activities. Natural vegetation patterns and our experimental results suggest that, without intervention, S. alterniflora could gradually replace these mangroves in mid-salinity regions of Chinese estuaries.


Assuntos
Ecossistema , Espécies Introduzidas , Rhizophoraceae/fisiologia , China , Atividades Humanas , Oceanos e Mares , Rios , Salinidade , Água/química
20.
J Environ Public Health ; 2022: 2974830, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36238824

RESUMO

Objective: The purpose of this article is to analyze the clinical effect of open reduction and internal fixation on femoral neck fracture in young adults and to explore the related factors of femoral head necrosis. Methods: The subjects were young and middle-aged femoral neck fracture patients admitted to our hospital from July 2019 to July 2021. 90 patients were randomly divided into two groups according to different treatment methods. The control group (n = 45) was treated with open reduction and internal fixation with hollow nails, while the observation group (n = 45) was treated with closed reduction and internal fixation with hollow nails. The clinical effects and adverse reactions of the two groups and the risk factors of avascular necrosis of femoral head were analyzed. Results: Compared with the control group, the operation time of the observation group was significantly shortened (P < 0.05), the amount of bleeding during the operation was significantly reduced (P < 0.05), and the incidence of total adverse reactions was significantly reduced (P < 0.05). The HSS score and Harris score of the two groups were significantly decreased after treatment (P < 0.05), but there was no significant difference in the above scores between the two groups before and after treatment (P > 0.05). The related risk factors of necrosis included gender, Garden classification, time from injury to operation, and time of weight bearing after operation (P < 0.05) but not related to age and cause of injury (P > 0.05). Conclusion: Open and closed reduction and internal fixation can effectively treat femoral neck fracture in young adults. The risk factors of adverse reactions of osteonecrosis include gender, Garden classification, time from injury to operation, and weight-bearing time after operation.


Assuntos
Fraturas do Colo Femoral , Necrose da Cabeça do Fêmur , Fraturas do Colo Femoral/etiologia , Fraturas do Colo Femoral/cirurgia , Necrose da Cabeça do Fêmur/etiologia , Fixação Interna de Fraturas/métodos , Humanos , Incidência , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Adulto Jovem
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