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1.
J Environ Manage ; 355: 120365, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38460328

RESUMO

Land use/land cover (LULC) change and climate change are interconnected factors that affect the ecological environment. However, there is a lack of quantification of the impacts of LULC change and climate change on landscape ecological risk under different shared socioeconomic pathways and representative concentration pathways (SSP-RCP) on the Mongolian Plateau (MP). To fill this knowledge gap and understand the current and future challenges facing the MP's land ecological system, we conducted an evaluation and prediction of the effects of LULC change and climate change on landscape ecological risk using the landscape loss index model and random forest method, considering eight SSP-RCP coupling scenarios. Firstly, we selected MCD12Q1 as the optimal LULC product for studying landscape changes on the MP, comparing it with four other LULC products. We analyzed the diverging patterns of LULC change over the past two decades and observed significant differences between Mongolia and Inner Mongolia. The latter experienced more intense and extensive LULC change during this period, despite similar climate changes. Secondly, we assessed changes in landscape ecological risk and identified the main drivers of these changes over the past two decades using a landscape index model and random forest method. The highest-risk zone has gradually expanded, with a 30% increase compared to 2001. Lastly, we investigated different characteristics of LULC change under different scenarios by examining future LULC products simulated by the FLUS model. We also simulated the dynamics of landscape ecological risks under these scenarios and proposed an adaptive development strategy to promote sustainable development in the MP. In terms of the impact of climate change on landscape ecological risk, we found that under the same SSP scenario, increasing RCP emission concentrations significantly increased the areas with high landscape ecological risk while decreasing areas with low risk. By integrating quantitative assessments and scenario-based modeling, our study provides valuable insights for informing sustainable land management and policy decisions in the region.


Assuntos
Mudança Climática , Conservação dos Recursos Naturais , Conservação dos Recursos Naturais/métodos , Ecossistema , Desenvolvimento Sustentável , Previsões
2.
Sci Total Environ ; 718: 137252, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32325613

RESUMO

The relationships between biodiversity and ecosystem functioning (BEF) have been extensively studied over past decades. However, the environmental factors affecting their relationships, and how their relationships vary under the influence of environmental factors, remain controversial. Studying the BEF relationships in natural/wild environments is of great significance for devising strategies in biodiversity conservation and ecosystem functioning. Using the data from 75 sites on the Mongolian Plateau steppe, we analyzed the relationship between species richness and biomass with general linear models (GLMs) and linear mixed models (LMMs), and analyzed the variation in the species richness-biomass relationships under environmental conditions by the partial least square path modeling (PLSPM). The results showed that de Martonne aridity index affected both species richness and community biomass in parallel, and that hydrothermal coupling conditions were more important direct impact factors for aboveground biomass. However, the significant species richness-biomass relationships became weaker when the effects of environmental factors (i.e. climate and soil properties) were present. Climate humidity was the most important factor in mediating the relationship between species richness and community biomass. Our research suggested that species richness-biomass relationships are weak in the natural grasslands of the Mongolian Plateau, and that this may be due to the differences in the regional-scale environment and changes in species interactions. We recommend that a more comprehensive understanding of the relationship between diversity and biomass requires further research within broader environmental gradients.


Assuntos
Biodiversidade , Biomassa , Umidade , Solo
3.
Ann Bot ; 124(3): 461-469, 2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31161191

RESUMO

BACKGROUND AND AIMS: Long-term studies to disentangle the multiple, simultaneous effects of global change on community dynamics are a high research priority to forecast future distribution of diversity. Seldom are such multiple effects of global change studied across different ecosystems. METHODS: Here we manipulated nitrogen deposition and rainfall at levels realistic for future environmental scenarios in three contrasting steppe types in Mongolia and followed community dynamics for 7 years. KEY RESULTS: Redundancy analyses showed that community composition varied significantly among years. Rainfall and nitrogen manipulations did have some significant effects, but these effects were dependent on the type of response and varied between ecosystems. Community compositions of desert and meadow steppes, but not that of typical steppe, responded significantly to rainfall addition. Only community composition of meadow steppe responded significantly to nitrogen deposition. Species richness in desert steppe responded significantly to rainfall addition, but the other two steppes did not. Typical steppe showed significant negative response of species richness to nitrogen deposition, but the other two steppes did not. There were significant interactions between year and nitrogen deposition in desert steppe and between year and rainfall addition in typical steppe, suggesting that the effect of the treatments depends on the particular year considered. CONCLUSIONS: Our multi-year experiment thus suggests that responses of community structure and diversity to global change drivers are ecosystem-dependent and that their responses to experimental treatments are dwarfed by the year-to-year community dynamics. Therefore, our results point to the importance of taking annual environmental variability into account for understanding and predicting the specific responses of different ecosystems to multiple global change drivers.


Assuntos
Ecossistema , Nitrogênio , China , Meio Ambiente
4.
J Nat Med ; 68(4): 717-22, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24845807

RESUMO

A rapid selection system was used to screen Glycyrrhiza uralensis plants containing high concentrations of glycyrrhizin (GC) by Eastern blotting using anti-GC monoclonal antibody (MAb). Chromatographic fingerprinting by Eastern blotting correlated with the GC concentration analyzed by enzyme-linked immunosorbent assay (ELISA). The roots of wild G. uralensis growing in Mongolia were analyzed by Eastern blotting to identify plants containing high concentrations of GC, and the GC concentration was confirmed by ELISA. G. uralensis plants cultivated in the greenhouse were also analyzed in the same manner. GC concentrations in wild G. uralensis roots and cultivated plants varied widely: between 0.06 and 9.36 percent dry weight (dw%). To confirm the homogeneity of GC concentrations in the cultivated plants, we monitored GC concentrations in the plants over 2 years. Although GC concentrations changed in two plants, they remained comparatively constant in the other five plants, suggesting that GC concentrations are genetically determined. To identify high GC-producing plants, 1025 plants were analyzed, and the highest concentration of GC was 5.36 dw%.


Assuntos
Glycyrrhiza uralensis/imunologia , Ácido Glicirrízico/imunologia , Immunoblotting/métodos , Anticorpos Monoclonais , Cruzamento , Ensaio de Imunoadsorção Enzimática , Glycyrrhiza uralensis/química , Ácido Glicirrízico/análise , Raízes de Plantas/química
5.
PLoS One ; 8(10): e77565, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24116233

RESUMO

BACKGROUND: The Mongolian steppe is one of the most important grasslands in the world but suffers from aridization and damage from anthropogenic activities. Understanding structure and function of this community is important for the ecological conservation, but has seldom been investigated. METHODOLOGY/PRINCIPAL FINDINGS: In this study, a total of 324 quadrats located on the three main types of Mongolian steppes were surveyed. Early-season perennial forbs (37% of total importance value), late-season annual forbs (33%) and late-season perennial forbs (44%) were dominant in meadow, typical and desert steppes, respectively. Species richness, diversity and plant functional type (PFT) richness decreased from the meadow, via typical to desert steppes, but evenness increased; PFT diversity in the desert and meadow steppes was higher than that in typical steppe. However, above-ground net primary productivity (ANPP) was far lower in desert steppe than in the other two steppes. In addition, the slope of the relationship between species richness and PFT richness increased from the meadow, via typical to desert steppes. Similarly, with an increase in species diversity, PFT diversity increased more quickly in both the desert and typical steppes than that in meadow steppe. Random resampling suggested that this coordination was partly due to a sampling effect of diversity. CONCLUSIONS/SIGNIFICANCE: These results indicate that desert steppe should be strictly protected because of its limited functional redundancy, which its ecological functioning is sensitive to species loss. In contrast, despite high potential forage production shared by the meadow and typical steppes, management of these two types of steppes should be different: meadow steppe should be preserved due to its higher conservation value characterized by more species redundancy and higher spatial heterogeneity, while typical steppe could be utilized moderately because its dominant grass genus Stipa is resistant to herbivory and drought.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Plantas , Conservação dos Recursos Naturais/métodos , Mongólia , Fenômenos Fisiológicos Vegetais , Plantas/classificação , Estações do Ano
6.
Curr Drug Discov Technol ; 8(1): 16-23, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21143132

RESUMO

The crude-rhizome extract of P. japonicus was loaded on the immunoaffinity column conjugated with anti- ginsenoside-Rb1 monoclonal antibody (MAb) and washed with the washing solvent, followed by elution solvent, to give fraction 2 containing higher concentration of compound 1. Compound 1 clearly indicated a dammarane saponin having protopanaxadiol as a framework and three sugars in a molecule suggesting that compound 1 is chikusetsusaponin III. Compound 2 was also determined as chikusetsusaponin VI compared to the staining color, its Rf value and the comparison with ginsenoside Rb1. We succeeded in one step purification of ginsenoside-Rb1 by immunoaffinity column conjugated with anti- ginsenoside-Rb1 MAb leading to the knock-out extract which will be useful for pharmacological investigation. The antibody was stable when exposed to the eluent, and the immunoaffinity column showed almost no decrease in capacity after repeated use more than 10 times under the same conditions. From the crude extract of licorice we isolated glycyrrhizin by one-step purification by the immunoaffinity column using anti-glycyrrhizin MAb. Washing fraction contained all components except for only glycyrrhizin and was named as the knockout extract. We confirmed the synergic effect of glycyrrhizin with some other components for the inhibition of nitric oxide (NO) production by blocking inducible nitric oxide synthase (iNOS) expression by using its knockout extract.


Assuntos
Anticorpos Monoclonais/análise , Ginsenosídeos/imunologia , Ácido Glicirrízico/análise , Óxido Nítrico/análise , Panax/química , Extratos Vegetais/análise , Anticorpos Monoclonais/imunologia , Cromatografia de Afinidade , Misturas Complexas/análise , Misturas Complexas/farmacologia , Ginsenosídeos/antagonistas & inibidores , Ácido Glicirrízico/imunologia , Imunoensaio , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/análise , Extratos Vegetais/farmacologia , Rizoma , Saponinas/análise
7.
Z Naturforsch C J Biosci ; 63(5-6): 413-7, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18669029

RESUMO

Licorice plants, Glycyrrhiza glabra, G. uralensis, and G. inflata, were investigated for callus induction using Murashige and Skoog (MS) medium combined with auxins and cytokinins. After 4 weeks of culture, 33-100% of leaf or stem explants formed calli. Maximum of shoot induction from callus cultures was achieved by G. inflata stem explants cultured on MS medium supplemented with 1 mg/l alpha-naphthaleneacetic acid (NAA) and 0.5 mg/l 6-benzyladenine (BA) (67%) which also gave maximum shoot formation per explant (two shoots per explant). These results indicated that all three Glycyrrhiza species regenerated shoots from callus cultures on MS medium combined with NAA and BA or only thidiazuron (TDZ; 0.1 and 0.5 mg/l). Glycyrrhizin contents of G. uralensis calli induced using MS medium in combination with NAA and BA [(27.60 +/- 8.47) microg/g DW] or TDZ alone [(36.52 +/- 2.45) microg/ g DW] were higher than those found in other combinations.


Assuntos
Glycyrrhiza/metabolismo , Ácido Glicirrízico/metabolismo , Células Cultivadas , Glycyrrhiza/citologia , Brotos de Planta/metabolismo , Sementes/metabolismo
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