To investigate the effects of environmental stresses on ascorbic acid content and its redox status, the effects of freezing and drought on ascorbate and dehydro-ascorbate content and activities of four enzymes involve...To investigate the effects of environmental stresses on ascorbic acid content and its redox status, the effects of freezing and drought on ascorbate and dehydro-ascorbate content and activities of four enzymes involved in the ascorbate-glutathione cycle in some conifers were studied. The results showed that both freezing and drought induced the decrease in ascorbate content and the increase in dehydro-ascorbate content. The activities of ascorbate peroxidase (APX) and monodehydro-ascorbate reductase (MDAR) were decreased by freezing stress. At the beginning of exposure to air, water loss from detached needles induced the increase in the activities of APX and MDAR. Further water loss turned to decrease the APX and MDAR activities. The activities of dehydro-ascorbate reductase (DHAR) and glutathione reductase (GR) were not sensitive to changes in temperature and water content of the needles. It is concluded that moderate temperature or water stresses may induce the acclimation and increase in the ability of the H2O2 scavenging system, while strong stresses decrease the ability and induce injury of plant tissues. Correlation between ascorbate content and activities of related enzymes and cold tolerance of conifers were also reported.展开更多
Aim. Comparison of the trascranial Doppler (TCD) characteristics of cerebral circulation in persistent vegetative status (PVS), locked in syndrome and brain death patients. Methods. Using ...Aim. Comparison of the trascranial Doppler (TCD) characteristics of cerebral circulation in persistent vegetative status (PVS), locked in syndrome and brain death patients. Methods. Using TCD ultrasound to detect the flow velocity and waveform patterns of middle cerebral artery (MCA) and basilar artery (BA) in patients with PVS, locked in syndrome and brain death. Results. The mean velocities of middle cerebral artery (Vmca) and basilar artery (Vba) were 30.0cm/s and 24.3cm/s in PVS patients respectively, which decreased 45.0% and 14.4% in comparing with normal value. For patients with locked in syndrome, Vmca and Vba were 49.7cm/s and 9.8cm/s, which decreased 5.0% and 61.7% than the normal value respectively. These results showed that the decrease of anterior circulation was predominant in PVS, and the decrease of posterior circulation was predominant in locked in syndrome. A unique diastolic reverse flow, short peak systolic wave or undetectable flow signal in middle cerebral artery were predominant in brain death patients, which was completely different from that of either PVS or locked in syndrome. Conclusion. TCD was a valuable tool in distinguishing PVS, locked in syndrome and brain death patients according to the differences in velocities and patterns of anterior and posterior cerebral arteries.展开更多
The aim of this study was to determine the phytoplankton community structures of reservoirs of different trophic status, located in a cold region. Physical and chemical variables and the phytoplankton communities were...The aim of this study was to determine the phytoplankton community structures of reservoirs of different trophic status, located in a cold region. Physical and chemical variables and the phytoplankton communities were investigated in two reservoirs (Xiquanyan Reservoir and Taoshan Reservoir) in Northeast China in 2009. The two reservoirs showed strong seasonal fluctuations in their physical and chemical composition. Results of the trophic status index indicated that Xiaquanyan Reservoir was mesotrophic, whilst Taoshan Reservoir was eutrophic. Diatoms were the dominant phytoplankton group in Xiquanyan Reservoir throughout all seasons of the study, while in Taoshan Reservoir, diatoms dominated in spring, and cyanobacteria dominated in summer and autumn. This difference was resulted from differences in local environmental factors, including nutrients and hydrology. This study suggests that in mesotrophic reservoirs, nutrients played a key role in controlling seasonal phytoplankton successions, whereas in eutrophic reservoirs water temperature was the key factor in a cold region. Notably, the dominant species in summer in the Taoshan Reservoir was Microcystis, which may produce toxins depending on the ambient conditions, and presenting a risk of local toxin contamination.展开更多
The taxonomic status of the medicinal plants in Jordan is expressed in terms of its diversity, the documentation of the scientific research that is carried out locally over the last many years; to test for the potenti...The taxonomic status of the medicinal plants in Jordan is expressed in terms of its diversity, the documentation of the scientific research that is carried out locally over the last many years; to test for the potential of some medicinal plant species (MPS) in Jordan on different biological aspects is also prepared. This has been reported here by revising and documenting the available literature to the author on this subject. The ecological status of medicinal plants in Jordar is also pointed out. The aim of this research was mainly to evaluate the status of the research on medicinal plants that was carried oul: to test for the different biological potentials of medicinal plants in Jordan and to emphasis the richness of the country of its wild medicinal plants, which are of promising value in whether for use in traditional medicine or in pharmaceutical industry, and certainly need lots of investigations and scientific research. Photographs of some medicinal plants that are common in Jordan and are used in traditional medicine in the urban areas and the Badia region, which is located in the Eastern part of the country and characterized by its dry weather conditions and least amount of rainfall in the country, are also included; the plant photographs are selected from different representative families of the common flowering plants in Jordan.展开更多
The study was conducted to investigate the mercury status in three major marshes in southeast Iraq. Sediments, plants (three species) and fish (five species) samples were collected at five locations along the majo...The study was conducted to investigate the mercury status in three major marshes in southeast Iraq. Sediments, plants (three species) and fish (five species) samples were collected at five locations along the major marshes (AL-Hammar, Cross of AI Fuhod AI Tar, Downstream of AL-Mashab & AL-Salal, Hawizeh and AL-Chebayesh) in southeast Iraq and analysed for mercury concentrations. The sediments were collected at predetermined input and output sources. The mercury concentrations were extremely high in both the sediment and plant samples but variable in fish species. There was a strong relationship between mercury concentrations in the sediments and fishes. Some of the fish species have mercury levels that are considered safe by the international marketing standard/WHO recommendation while others contain mercury levels that may be considered unsafe for human consumption.展开更多
When facilitating other species and sustaining plant community structures and biodiversity,alpine cushion plants simultaneously experience negative feedback effects from surrounding vegetation.However,the impact of su...When facilitating other species and sustaining plant community structures and biodiversity,alpine cushion plants simultaneously experience negative feedback effects from surrounding vegetation.However,the impact of surrounding vegetation on cushion dynamics remains poorly understood,particularly in terms of allelopathic potentials.To investigate the allelopathic potentials of surrounding vegetation on seedling establishment of the typical cushion plant Arenaria polytrichoides Edgew.along an elevational gradient,we extracted potential allelopathic compounds and tested their impacts on seed germination and seedling growth of A.polytrichoides.In addition,exclusion experiments using activated carbon were conducted to further elucidate these effects.Our results demonstrate that surrounding vegetation exhibits certain allelopathic potentials on A.polytrichoides seedling establishment,with variations observed based on elevation,source and concentration of allelopathy compounds,as well as growing season.Specifcally,low-elevation vegetation exerts pronounced suppression on seedling establishment.Conversely,higher-elevation vegetation generally shows no effect on seed germination but stimulates seedling growth through allelopathy mechanisms.Moreover,aboveground vegetation predominantly inhibits both seed germination and seedling growth in low-elevation communities;however,the effects of belowground vegetation depend on elevation and extract concentration levels.The identifed allelopathic potentials of surrounding vegetation signifcantly infuence the population dynamics of cushion A.polytrichoides by potentially accelerating population degeneration in lower-elevation communities while ensuring consistent population recruitment and expansion in higher-elevation communities.展开更多
Objective To explore the effects of acupuncture on nutritional status in patients in a persistent vegetative state.Methods A prospective randomized controlled trial was designed.A total of 66 patients in a persistent ...Objective To explore the effects of acupuncture on nutritional status in patients in a persistent vegetative state.Methods A prospective randomized controlled trial was designed.A total of 66 patients in a persistent vegetative state were randomized into a control group and an observation group,with 33 cases in each group.The control group was given conventional treatment plus enteral nutrition support.The observation group was treated with additional Tiao Shen Jian Pi acupuncture therapy(acupuncture for spirit-regulating and spleen-invigorating)based on the same interventions in the control group.Both groups were treated for 8 weeks.The levels of total protein(TP),prealbumin(PA),albumin(Alb),and hemoglobin(Hb)were measured before and after treatment.The upper arm circumference and skinfold thickness of triceps brachii were measured.And the intestinal flora and fecal short-chain fatty acids contents were determined.Results After treatment,the levels of TP,PA,Alb,and Hb in the control group were decreased(P<0.05),while in the observation group,compared with those before treatment,the levels of TP,PA,Alb,and Hb had no statistical differences(P>0.05),and the levels were all higher than those in the control group(P<0.05).The upper arm circumference and skinfold thickness of triceps brachii in both groups decreased(P<0.05),and the values of these two items in the observation group were higher than those in the control group(P<0.05).In the control group,the contents of Bifidobacterium and Lactobacillus in feces decreased(P<0.05),and the content of Enterococcus increased(P<0.05).In the observation group,the contents of Bifidobacterium and Lactobacillus in feces increased(P<0.05),and the content of Enterococcus decreased(P<0.05).The differences between the two groups were statistically significant(P<0.05).In the control group,the total content of fecal short-chain fatty acids and the contents of acetic acid and butyric acid in feces decreased(P<0.05).In the observation group,the total content of fecal short-chain fatty acids and the contents of acetic acid and butyric acid in feces increased(P<0.05)and were all higher than those in the control group(P<0.05).Conclusion Acupuncture can improve nutrition-related blood indicators in patients in a persistent vegetative state and delay the decrease of upper arm circumference and skinfold thickness of triceps brachii,which may be related to the regulation of intestinal flora and fecal short-chain fatty acids contents.展开更多
Aims Functional traits are usually used to predict plant demographic rates without considering environmental contexts.However,previous studies have consistently found that traits have low explanatory power for plant d...Aims Functional traits are usually used to predict plant demographic rates without considering environmental contexts.However,previous studies have consistently found that traits have low explanatory power for plant demographic rates.We hypothesized that accounting for environmental contexts instead of focusing on traits alone could improve our understanding of how traits influence plant demographic rates.Methods We used generalized linear mixed-effect models to analyse the effects of functional traits(related to leaf,stem,seed and whole plant),environmental gradients(soil nutrients,water and elevation)and their interactions on the survival dynamics of 14133 saplings and 3289 adults in a 9-ha old-growth temperate forest plot.Important Findings We found that environmental variables,neighbour crowding and traits alone(i.e.main effects)influenced plant survival.However,the effects of the latter two variables varied between saplings and adults.The trait–environment interactions influenced plant survival,such that resource conservative traits increased plant survival under harsh conditions but decreased survival under mild conditions.The elevational gradient was the most important environmental factor driving these effects in our plot.Our results support the hypothesis that functional traits influence plant survival depending on environmental contexts in local communities.These results also imply that one species with limited trait variation cannot occupy all environments,which can promote species diversity.展开更多
Aims Biomass allocation to different organs is a fundamental plant ecophysiological process to better respond to changing environments;yet,it remains poorly understood how patterns of biomass allocation respond to nit...Aims Biomass allocation to different organs is a fundamental plant ecophysiological process to better respond to changing environments;yet,it remains poorly understood how patterns of biomass allocation respond to nitrogen(N)additions across terrestrial ecosystems worldwide.Methods We conducted a meta-analysis using 5474 pairwise observations from 333 articles to assess how N addition affected plant biomass and biomass allocation among different organs.We also tested the'ratio-based optimal partitioning'vs.the'isometric allocation,hypotheses to explain potential N addition effects on biomass allocation.Important Findings We found that(i)N addition significantly increased whole plant biomass and the biomass of different organs,but decreased rootrshoot ratio(RS)and root mass fraction(RMF)while no effects of N addition on leaf mass fraction and stem mass fraction at the global scale;(ii)the effects of N addition on ratio-based biomass allocation were mediated by individual or interactive effects of moderator variables such as experimental conditions,plant functional types,latitudes and rates of N addition and(iii)N addition did not affect allometric relationships among different organs,suggesting that decreases in RS and RMF may result from isometric allocation patterns following increases in whole plant biomass.Despite alteration of ratio-based biomass allocation between root and shoot by N addition,the unaffected allometric scaling relationships among different organs(including root vs.shoot)suggest that plant biomass allocation patterns are more appropriately explained by the isometric allocation hypothesis rather than the optimal partitioning hypothesis.Our findings contribute to better understand N-induced effects on allometric relationships of terrestrial plants,and suggest that these ecophysiological responses should be incorporated into models that aim to predict how terrestrial ecosystems may respond to enhanced N deposition under future global change scenarios.展开更多
Environmental risks pertaining to contaminated soils have been well studied,while little attention has been paid to the risks of the soils after remediation. In this study,a concept model developed based on fuzzy set ...Environmental risks pertaining to contaminated soils have been well studied,while little attention has been paid to the risks of the soils after remediation. In this study,a concept model developed based on fuzzy set theory was applied to evaluate the uncertainties of three risk indicators,namely,plant growth,groundwater safety and human health,of a restored site that had been previously polluted by heavy metals. The concept model classified the grade and importance of risk factors by an 11-level ranking system and was able to yield a comprehensive risk result rather than multi-risk results for complex risk indicators. Modeling results showed that the risks to the three indicators were effectively reduced after the remediation. Moreover,great sensitivity of the risks was found related to the weight distribution among the three risk indicators. In general,the risks of both polluted and restored soils to the environment were in the order of groundwater safety > plant growth > human health. The model was proved to solve the problems of multi-risk results due to complex risk indicators that previously encountered by other researchers,which made it helpful in decision-making and management of restored soils.展开更多
文摘To investigate the effects of environmental stresses on ascorbic acid content and its redox status, the effects of freezing and drought on ascorbate and dehydro-ascorbate content and activities of four enzymes involved in the ascorbate-glutathione cycle in some conifers were studied. The results showed that both freezing and drought induced the decrease in ascorbate content and the increase in dehydro-ascorbate content. The activities of ascorbate peroxidase (APX) and monodehydro-ascorbate reductase (MDAR) were decreased by freezing stress. At the beginning of exposure to air, water loss from detached needles induced the increase in the activities of APX and MDAR. Further water loss turned to decrease the APX and MDAR activities. The activities of dehydro-ascorbate reductase (DHAR) and glutathione reductase (GR) were not sensitive to changes in temperature and water content of the needles. It is concluded that moderate temperature or water stresses may induce the acclimation and increase in the ability of the H2O2 scavenging system, while strong stresses decrease the ability and induce injury of plant tissues. Correlation between ascorbate content and activities of related enzymes and cold tolerance of conifers were also reported.
文摘Aim. Comparison of the trascranial Doppler (TCD) characteristics of cerebral circulation in persistent vegetative status (PVS), locked in syndrome and brain death patients. Methods. Using TCD ultrasound to detect the flow velocity and waveform patterns of middle cerebral artery (MCA) and basilar artery (BA) in patients with PVS, locked in syndrome and brain death. Results. The mean velocities of middle cerebral artery (Vmca) and basilar artery (Vba) were 30.0cm/s and 24.3cm/s in PVS patients respectively, which decreased 45.0% and 14.4% in comparing with normal value. For patients with locked in syndrome, Vmca and Vba were 49.7cm/s and 9.8cm/s, which decreased 5.0% and 61.7% than the normal value respectively. These results showed that the decrease of anterior circulation was predominant in PVS, and the decrease of posterior circulation was predominant in locked in syndrome. A unique diastolic reverse flow, short peak systolic wave or undetectable flow signal in middle cerebral artery were predominant in brain death patients, which was completely different from that of either PVS or locked in syndrome. Conclusion. TCD was a valuable tool in distinguishing PVS, locked in syndrome and brain death patients according to the differences in velocities and patterns of anterior and posterior cerebral arteries.
基金Supported by the Fundamental Research Funds for the Central Universities(No.DL11BA20)the GRAP09-Excellent Doctor Paper of Northeast Forestry Universitythe Science and Technology Project of Heilongjiang Province(No.GBQ9C103)
文摘The aim of this study was to determine the phytoplankton community structures of reservoirs of different trophic status, located in a cold region. Physical and chemical variables and the phytoplankton communities were investigated in two reservoirs (Xiquanyan Reservoir and Taoshan Reservoir) in Northeast China in 2009. The two reservoirs showed strong seasonal fluctuations in their physical and chemical composition. Results of the trophic status index indicated that Xiaquanyan Reservoir was mesotrophic, whilst Taoshan Reservoir was eutrophic. Diatoms were the dominant phytoplankton group in Xiquanyan Reservoir throughout all seasons of the study, while in Taoshan Reservoir, diatoms dominated in spring, and cyanobacteria dominated in summer and autumn. This difference was resulted from differences in local environmental factors, including nutrients and hydrology. This study suggests that in mesotrophic reservoirs, nutrients played a key role in controlling seasonal phytoplankton successions, whereas in eutrophic reservoirs water temperature was the key factor in a cold region. Notably, the dominant species in summer in the Taoshan Reservoir was Microcystis, which may produce toxins depending on the ambient conditions, and presenting a risk of local toxin contamination.
文摘The taxonomic status of the medicinal plants in Jordan is expressed in terms of its diversity, the documentation of the scientific research that is carried out locally over the last many years; to test for the potential of some medicinal plant species (MPS) in Jordan on different biological aspects is also prepared. This has been reported here by revising and documenting the available literature to the author on this subject. The ecological status of medicinal plants in Jordar is also pointed out. The aim of this research was mainly to evaluate the status of the research on medicinal plants that was carried oul: to test for the different biological potentials of medicinal plants in Jordan and to emphasis the richness of the country of its wild medicinal plants, which are of promising value in whether for use in traditional medicine or in pharmaceutical industry, and certainly need lots of investigations and scientific research. Photographs of some medicinal plants that are common in Jordan and are used in traditional medicine in the urban areas and the Badia region, which is located in the Eastern part of the country and characterized by its dry weather conditions and least amount of rainfall in the country, are also included; the plant photographs are selected from different representative families of the common flowering plants in Jordan.
文摘The study was conducted to investigate the mercury status in three major marshes in southeast Iraq. Sediments, plants (three species) and fish (five species) samples were collected at five locations along the major marshes (AL-Hammar, Cross of AI Fuhod AI Tar, Downstream of AL-Mashab & AL-Salal, Hawizeh and AL-Chebayesh) in southeast Iraq and analysed for mercury concentrations. The sediments were collected at predetermined input and output sources. The mercury concentrations were extremely high in both the sediment and plant samples but variable in fish species. There was a strong relationship between mercury concentrations in the sediments and fishes. Some of the fish species have mercury levels that are considered safe by the international marketing standard/WHO recommendation while others contain mercury levels that may be considered unsafe for human consumption.
基金supported by the Second Tibetan Plateau Scientifc Expedition and Research Program(2019QZKK0502)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20050203)+1 种基金the Yunnan Applied Basic Research Project(202001AT070060,202301AS070058)the Young Academic and Technical Leader Raising Foundation of Yunnan Province(202205AC160053)。
文摘When facilitating other species and sustaining plant community structures and biodiversity,alpine cushion plants simultaneously experience negative feedback effects from surrounding vegetation.However,the impact of surrounding vegetation on cushion dynamics remains poorly understood,particularly in terms of allelopathic potentials.To investigate the allelopathic potentials of surrounding vegetation on seedling establishment of the typical cushion plant Arenaria polytrichoides Edgew.along an elevational gradient,we extracted potential allelopathic compounds and tested their impacts on seed germination and seedling growth of A.polytrichoides.In addition,exclusion experiments using activated carbon were conducted to further elucidate these effects.Our results demonstrate that surrounding vegetation exhibits certain allelopathic potentials on A.polytrichoides seedling establishment,with variations observed based on elevation,source and concentration of allelopathy compounds,as well as growing season.Specifcally,low-elevation vegetation exerts pronounced suppression on seedling establishment.Conversely,higher-elevation vegetation generally shows no effect on seed germination but stimulates seedling growth through allelopathy mechanisms.Moreover,aboveground vegetation predominantly inhibits both seed germination and seedling growth in low-elevation communities;however,the effects of belowground vegetation depend on elevation and extract concentration levels.The identifed allelopathic potentials of surrounding vegetation signifcantly infuence the population dynamics of cushion A.polytrichoides by potentially accelerating population degeneration in lower-elevation communities while ensuring consistent population recruitment and expansion in higher-elevation communities.
文摘Objective To explore the effects of acupuncture on nutritional status in patients in a persistent vegetative state.Methods A prospective randomized controlled trial was designed.A total of 66 patients in a persistent vegetative state were randomized into a control group and an observation group,with 33 cases in each group.The control group was given conventional treatment plus enteral nutrition support.The observation group was treated with additional Tiao Shen Jian Pi acupuncture therapy(acupuncture for spirit-regulating and spleen-invigorating)based on the same interventions in the control group.Both groups were treated for 8 weeks.The levels of total protein(TP),prealbumin(PA),albumin(Alb),and hemoglobin(Hb)were measured before and after treatment.The upper arm circumference and skinfold thickness of triceps brachii were measured.And the intestinal flora and fecal short-chain fatty acids contents were determined.Results After treatment,the levels of TP,PA,Alb,and Hb in the control group were decreased(P<0.05),while in the observation group,compared with those before treatment,the levels of TP,PA,Alb,and Hb had no statistical differences(P>0.05),and the levels were all higher than those in the control group(P<0.05).The upper arm circumference and skinfold thickness of triceps brachii in both groups decreased(P<0.05),and the values of these two items in the observation group were higher than those in the control group(P<0.05).In the control group,the contents of Bifidobacterium and Lactobacillus in feces decreased(P<0.05),and the content of Enterococcus increased(P<0.05).In the observation group,the contents of Bifidobacterium and Lactobacillus in feces increased(P<0.05),and the content of Enterococcus decreased(P<0.05).The differences between the two groups were statistically significant(P<0.05).In the control group,the total content of fecal short-chain fatty acids and the contents of acetic acid and butyric acid in feces decreased(P<0.05).In the observation group,the total content of fecal short-chain fatty acids and the contents of acetic acid and butyric acid in feces increased(P<0.05)and were all higher than those in the control group(P<0.05).Conclusion Acupuncture can improve nutrition-related blood indicators in patients in a persistent vegetative state and delay the decrease of upper arm circumference and skinfold thickness of triceps brachii,which may be related to the regulation of intestinal flora and fecal short-chain fatty acids contents.
基金This study was financially supported by the NationalNatural Science Foundation of China(31870399,32071533)the Strategic Priority ResearchProgram of the Chinese Academy of Sciences(XDB31030000).
文摘Aims Functional traits are usually used to predict plant demographic rates without considering environmental contexts.However,previous studies have consistently found that traits have low explanatory power for plant demographic rates.We hypothesized that accounting for environmental contexts instead of focusing on traits alone could improve our understanding of how traits influence plant demographic rates.Methods We used generalized linear mixed-effect models to analyse the effects of functional traits(related to leaf,stem,seed and whole plant),environmental gradients(soil nutrients,water and elevation)and their interactions on the survival dynamics of 14133 saplings and 3289 adults in a 9-ha old-growth temperate forest plot.Important Findings We found that environmental variables,neighbour crowding and traits alone(i.e.main effects)influenced plant survival.However,the effects of the latter two variables varied between saplings and adults.The trait–environment interactions influenced plant survival,such that resource conservative traits increased plant survival under harsh conditions but decreased survival under mild conditions.The elevational gradient was the most important environmental factor driving these effects in our plot.Our results support the hypothesis that functional traits influence plant survival depending on environmental contexts in local communities.These results also imply that one species with limited trait variation cannot occupy all environments,which can promote species diversity.
基金This research was financially supported by the National Natural Science Foundation of China(31922052,31800373,32022056 and 31800521).
文摘Aims Biomass allocation to different organs is a fundamental plant ecophysiological process to better respond to changing environments;yet,it remains poorly understood how patterns of biomass allocation respond to nitrogen(N)additions across terrestrial ecosystems worldwide.Methods We conducted a meta-analysis using 5474 pairwise observations from 333 articles to assess how N addition affected plant biomass and biomass allocation among different organs.We also tested the'ratio-based optimal partitioning'vs.the'isometric allocation,hypotheses to explain potential N addition effects on biomass allocation.Important Findings We found that(i)N addition significantly increased whole plant biomass and the biomass of different organs,but decreased rootrshoot ratio(RS)and root mass fraction(RMF)while no effects of N addition on leaf mass fraction and stem mass fraction at the global scale;(ii)the effects of N addition on ratio-based biomass allocation were mediated by individual or interactive effects of moderator variables such as experimental conditions,plant functional types,latitudes and rates of N addition and(iii)N addition did not affect allometric relationships among different organs,suggesting that decreases in RS and RMF may result from isometric allocation patterns following increases in whole plant biomass.Despite alteration of ratio-based biomass allocation between root and shoot by N addition,the unaffected allometric scaling relationships among different organs(including root vs.shoot)suggest that plant biomass allocation patterns are more appropriately explained by the isometric allocation hypothesis rather than the optimal partitioning hypothesis.Our findings contribute to better understand N-induced effects on allometric relationships of terrestrial plants,and suggest that these ecophysiological responses should be incorporated into models that aim to predict how terrestrial ecosystems may respond to enhanced N deposition under future global change scenarios.
基金Supported by the National Natural Science Foundation of China(Nos.41171374 and 41101483)the Fundamental Research Funds for the Central Universities of China(No.101gzd10)+1 种基金the National Science Foundation for Distinguished Young Scholars of China(No.41225004)the National High Technology Research and Development Program of China(No.2012-AA-06A202)
文摘Environmental risks pertaining to contaminated soils have been well studied,while little attention has been paid to the risks of the soils after remediation. In this study,a concept model developed based on fuzzy set theory was applied to evaluate the uncertainties of three risk indicators,namely,plant growth,groundwater safety and human health,of a restored site that had been previously polluted by heavy metals. The concept model classified the grade and importance of risk factors by an 11-level ranking system and was able to yield a comprehensive risk result rather than multi-risk results for complex risk indicators. Modeling results showed that the risks to the three indicators were effectively reduced after the remediation. Moreover,great sensitivity of the risks was found related to the weight distribution among the three risk indicators. In general,the risks of both polluted and restored soils to the environment were in the order of groundwater safety > plant growth > human health. The model was proved to solve the problems of multi-risk results due to complex risk indicators that previously encountered by other researchers,which made it helpful in decision-making and management of restored soils.