[Objective]Vegetation restoration is an effective strategy for ecological improvement;however,inappropriate vegetation establishment can induce soil desiccation,thereby threatening ecosystem stability.Therefore,elucid...[Objective]Vegetation restoration is an effective strategy for ecological improvement;however,inappropriate vegetation establishment can induce soil desiccation,thereby threatening ecosystem stability.Therefore,elucidating the global response patterns of soil moisture to vegetation restoration and identifying research hotspots are critical for guiding ecological construction in arid regions.[Methods]We reviewed 6,152 articles concerning soil moisture and vegetation retrieved from the Web of Science platform.Using VOSviewer,we conducted analyses of keyword co-occurrence,publication trends,and research hotspots to systematically delineate the evolving trends in this field.[Results]The results indicate a significant increasing trend in the number of publications since 2000.Global research keywords are categorized into seven clusters,including vegetation,soil moisture,rainfall-erosion-infiltration,spatial heterogeneity,and climate change.In terms of highly cited papers in 2024,China and the United States maintain a significant lead.Global research demonstrates a strong dependency on typical regional geographical features(such as climate types and topography),exhibiting differentiated research focuses.Furthermore,studies extend beyond soil moisture itself to deeply couple with ecological processes such as vegetation restoration,soil respiration,carbon cycling,and hydrothermal conditions.[Conclusions]The long-term ecological effects of afforestation in arid regions remain unclear,and empirical data from key regions highlight the current urgency.Future research should integrate climate change dynamics,innovate monitoring methodologies,and deepen the understanding of regional differentiation to provide scientific support for the adaptive management of vegetation in arid regions.展开更多
A terahertz(THz)wave transmitted through vegetation experiences both absorption and scattering caused by the air molecules and leaves.This paper presents the scattering attenuation characteristics of vegetation in a T...A terahertz(THz)wave transmitted through vegetation experiences both absorption and scattering caused by the air molecules and leaves.This paper presents the scattering attenuation characteristics of vegetation in a THz range.The theoretical path loss model near the vegetation yields the average attenuation of THz waves in a mixed channel composed of air and vegetation leaves.Furthermore,a simplified model of the vegetation structure is obtained for generic vegetation types based on a variety of parameters,such as leaf size,distribution,and moisture content.Finally,based on specific vegetation species and different levels of air humidity,the attenuation characteristics under different conditions are calculated,and the influence of different model parameters on the attenuation characteristics is obtained.展开更多
Vegetation plays a key role in improving wind environment of residential districts,and is helpful for creating a comfortable and beautiful living environment.The optimal design of vegetation for wind environment impro...Vegetation plays a key role in improving wind environment of residential districts,and is helpful for creating a comfortable and beautiful living environment.The optimal design of vegetation for wind environment improvement in winter was investigated by carrying out field experiments in Heqingyuan residential area in Beijing,and after that,numerical simulation with SPOTE(simulation platform for outdoor thermal environment) experiments for outdoor thermal environment of vegetation was adopted for comparison.The conclusions were summarized as follows:1) By comparing the experimental data with simulation results,it could be concluded that the wind field simulated was consistent with the actual wind field,and the flow distribution impacted by vegetation could be accurately reflected;2) The wind velocity with vegetation was lower than that without vegetation,and the wind velocity was reduced by 46%;3) By adjusting arrangement and types of vegetation in the regions with excessively large wind velocity,the pedestrian-level wind velocity could be obviously improved through the simulation and comparison.展开更多
The vegetation of mainland Southeast Asia is less known to science.This article introduces the studies up to now on the vegetation of mainland Southeast Asia(Indochina peninsula),and describes the main fo-rest vegetat...The vegetation of mainland Southeast Asia is less known to science.This article introduces the studies up to now on the vegetation of mainland Southeast Asia(Indochina peninsula),and describes the main fo-rest vegetation types based on fragmentary information and field visits.Seven main terraneous and wet land forest vegetation types,including coniferous forest,coniferous-broad-leaved mixed forest,tropical montane evergreen broad-leaved forest,tropical rain forest,tropical seasonal moist forest,tropical monsoon forest,and dry thorny thickets/woodland(savanna),are recognized.Of them,the coniferous forest includes two subtypes:temperate coniferous forest and tropical coniferous forest;the coniferous-broad-leaved mixed forest includes also two subtypes:warm temperate and temperate coniferous-broadleaved mixed forests;and the tropical rain forest includes four main vegetation subtypes:tropical lowland evergreen rain forest,tropical seasonal rain forest(tropical lowland semi-evergreen rain forest),tropical montane rain forest,and peat swamp forest.The study history of the vegetation in the region,its classification,physiognomic characteristics,and dominant species composition,are also concisely introduced.展开更多
To clarify the role of waterfront vegetation of floodplains for adult aquatic insects, Trichoptera and Diptera (Tipulidae and Chironomidae), in the middle reaches of the Chikuma River from May to July, an investigatio...To clarify the role of waterfront vegetation of floodplains for adult aquatic insects, Trichoptera and Diptera (Tipulidae and Chironomidae), in the middle reaches of the Chikuma River from May to July, an investigation of the number of these insects was conducted by trapping in each type of vegetation using board traps.A total of 2608.5 adults/m 2 were collected, and we identified a total of 26 species belonging to three taxa,i.e., seven species of Trichoptera, four species of Tipulidae and 15 species of Chironomidae. The most abundant species was Psychomyia acutipennis in Trichoptera (95.7%). There was a significant difference between the number of P.acutipennis in the all vegetation area (especially, Salix subfragilis) and the control area (no vegetation) during the investigation periods (P<0.05, Mann-Whitney U-test). Other taxa did not show a significant difference between the all vegetation area and the control. Moreover, the numbers of adult P. acutipennis showed a significant difference in height on each vegetation. In the case of Vicia villosa varia and V. villosa varia plus dead Phragmites australis, the highest number was caught in the traps set in the boundary between one plant and the plant above (P<0.05, Steel-Dwass Test) in May.On the other hand, in the case of almost all vegetation during the investigation periods (except of S.subfragilis in May, Melilotus officinalis plus dead P.australis in June), the highest number was caught in the traps set up within the vegetation (P<0.05, Steel-Dwass Test).As a result, a significant difference was observed in the number of trapped P.acutipennis according to the vegetation and its height.It is suggested that the existence of multiple types of vegetation in the floodplain plays an important role for maintaining the diversity of the fauna there.展开更多
[Objective]With increasing energy demand and growing concerns about climate change,the rational utilization of marginal lands for cultivating biomass energy crops has emerged as a research focus in recent years.Previo...[Objective]With increasing energy demand and growing concerns about climate change,the rational utilization of marginal lands for cultivating biomass energy crops has emerged as a research focus in recent years.Previous studies have demonstrated that cultivating perennial biomass crops on marginal lands significantly impacts regional climate change and food production.However,these investigations did not fully consider the interactive feedback between plant growth and climate change,leading to slightly insufficient reliability of the result.[Methods]To address the limitations of earlier studies,the coupled model CWRF-BioCro was employed to comprehensively consider the interactive feedback between plant growth and climate change,and to analyze changes in regional precipitation patterns and their physical mechanisms under two scenarios in the United States:cultivation of perennial biomass crops on marginal lands and maintenance of existing vegetation cover.[Results]The result showed that after cultivating perennial biomass crops on marginal lands,the regional total average daily precipitation increased by 6.33 mm/day(0.01%),with most of the increase occurring during spring,summer,and autumn in the central and western regions and during autumn and winter in the eastern region.This was primarily due to the significant enhancement of water vapor transport and latent heat flux in the region.The regional maximum daily precipitation decreased by 2.1 mm(4.39%),mainly in the central and eastern regions,Resulting from a significant decrease in sensible heat flux in these regions.Meanwhile,the frequency of precipitation events with an average daily precipitation greater than 50 mm/d decreased in the central and eastern regions,with the most pronounced reduction of 31 days(0.24%)observed in events in the range of 50.0~99.9 mm/day.[Conclusion]In summary,planting perennial biomass crops on marginal lands can increase regional precipitation and reduce extreme precipitation.These findings highlight the critical role of biophysical feedback mechanisms in regulating regional climate and provide a scientific foundation for developing climate-adaptive land management strategies.展开更多
文摘[Objective]Vegetation restoration is an effective strategy for ecological improvement;however,inappropriate vegetation establishment can induce soil desiccation,thereby threatening ecosystem stability.Therefore,elucidating the global response patterns of soil moisture to vegetation restoration and identifying research hotspots are critical for guiding ecological construction in arid regions.[Methods]We reviewed 6,152 articles concerning soil moisture and vegetation retrieved from the Web of Science platform.Using VOSviewer,we conducted analyses of keyword co-occurrence,publication trends,and research hotspots to systematically delineate the evolving trends in this field.[Results]The results indicate a significant increasing trend in the number of publications since 2000.Global research keywords are categorized into seven clusters,including vegetation,soil moisture,rainfall-erosion-infiltration,spatial heterogeneity,and climate change.In terms of highly cited papers in 2024,China and the United States maintain a significant lead.Global research demonstrates a strong dependency on typical regional geographical features(such as climate types and topography),exhibiting differentiated research focuses.Furthermore,studies extend beyond soil moisture itself to deeply couple with ecological processes such as vegetation restoration,soil respiration,carbon cycling,and hydrothermal conditions.[Conclusions]The long-term ecological effects of afforestation in arid regions remain unclear,and empirical data from key regions highlight the current urgency.Future research should integrate climate change dynamics,innovate monitoring methodologies,and deepen the understanding of regional differentiation to provide scientific support for the adaptive management of vegetation in arid regions.
基金the Fundamental Research Funds for the Central Universities(NT2021026).
文摘A terahertz(THz)wave transmitted through vegetation experiences both absorption and scattering caused by the air molecules and leaves.This paper presents the scattering attenuation characteristics of vegetation in a THz range.The theoretical path loss model near the vegetation yields the average attenuation of THz waves in a mixed channel composed of air and vegetation leaves.Furthermore,a simplified model of the vegetation structure is obtained for generic vegetation types based on a variety of parameters,such as leaf size,distribution,and moisture content.Finally,based on specific vegetation species and different levels of air humidity,the attenuation characteristics under different conditions are calculated,and the influence of different model parameters on the attenuation characteristics is obtained.
基金Project(50878111) supported by the National Natural Science Foundation of China
文摘Vegetation plays a key role in improving wind environment of residential districts,and is helpful for creating a comfortable and beautiful living environment.The optimal design of vegetation for wind environment improvement in winter was investigated by carrying out field experiments in Heqingyuan residential area in Beijing,and after that,numerical simulation with SPOTE(simulation platform for outdoor thermal environment) experiments for outdoor thermal environment of vegetation was adopted for comparison.The conclusions were summarized as follows:1) By comparing the experimental data with simulation results,it could be concluded that the wind field simulated was consistent with the actual wind field,and the flow distribution impacted by vegetation could be accurately reflected;2) The wind velocity with vegetation was lower than that without vegetation,and the wind velocity was reduced by 46%;3) By adjusting arrangement and types of vegetation in the regions with excessively large wind velocity,the pedestrian-level wind velocity could be obviously improved through the simulation and comparison.
文摘The vegetation of mainland Southeast Asia is less known to science.This article introduces the studies up to now on the vegetation of mainland Southeast Asia(Indochina peninsula),and describes the main fo-rest vegetation types based on fragmentary information and field visits.Seven main terraneous and wet land forest vegetation types,including coniferous forest,coniferous-broad-leaved mixed forest,tropical montane evergreen broad-leaved forest,tropical rain forest,tropical seasonal moist forest,tropical monsoon forest,and dry thorny thickets/woodland(savanna),are recognized.Of them,the coniferous forest includes two subtypes:temperate coniferous forest and tropical coniferous forest;the coniferous-broad-leaved mixed forest includes also two subtypes:warm temperate and temperate coniferous-broadleaved mixed forests;and the tropical rain forest includes four main vegetation subtypes:tropical lowland evergreen rain forest,tropical seasonal rain forest(tropical lowland semi-evergreen rain forest),tropical montane rain forest,and peat swamp forest.The study history of the vegetation in the region,its classification,physiognomic characteristics,and dominant species composition,are also concisely introduced.
基金the River Environment Fundin charge of the Foundation of River Watershed Environment Management ,Japan and Grant-in-Aid for 21st Century COE Programbythe Ministry of Education,Culture ,Sports ,Science ,and Technology.
文摘To clarify the role of waterfront vegetation of floodplains for adult aquatic insects, Trichoptera and Diptera (Tipulidae and Chironomidae), in the middle reaches of the Chikuma River from May to July, an investigation of the number of these insects was conducted by trapping in each type of vegetation using board traps.A total of 2608.5 adults/m 2 were collected, and we identified a total of 26 species belonging to three taxa,i.e., seven species of Trichoptera, four species of Tipulidae and 15 species of Chironomidae. The most abundant species was Psychomyia acutipennis in Trichoptera (95.7%). There was a significant difference between the number of P.acutipennis in the all vegetation area (especially, Salix subfragilis) and the control area (no vegetation) during the investigation periods (P<0.05, Mann-Whitney U-test). Other taxa did not show a significant difference between the all vegetation area and the control. Moreover, the numbers of adult P. acutipennis showed a significant difference in height on each vegetation. In the case of Vicia villosa varia and V. villosa varia plus dead Phragmites australis, the highest number was caught in the traps set in the boundary between one plant and the plant above (P<0.05, Steel-Dwass Test) in May.On the other hand, in the case of almost all vegetation during the investigation periods (except of S.subfragilis in May, Melilotus officinalis plus dead P.australis in June), the highest number was caught in the traps set up within the vegetation (P<0.05, Steel-Dwass Test).As a result, a significant difference was observed in the number of trapped P.acutipennis according to the vegetation and its height.It is suggested that the existence of multiple types of vegetation in the floodplain plays an important role for maintaining the diversity of the fauna there.
文摘[Objective]With increasing energy demand and growing concerns about climate change,the rational utilization of marginal lands for cultivating biomass energy crops has emerged as a research focus in recent years.Previous studies have demonstrated that cultivating perennial biomass crops on marginal lands significantly impacts regional climate change and food production.However,these investigations did not fully consider the interactive feedback between plant growth and climate change,leading to slightly insufficient reliability of the result.[Methods]To address the limitations of earlier studies,the coupled model CWRF-BioCro was employed to comprehensively consider the interactive feedback between plant growth and climate change,and to analyze changes in regional precipitation patterns and their physical mechanisms under two scenarios in the United States:cultivation of perennial biomass crops on marginal lands and maintenance of existing vegetation cover.[Results]The result showed that after cultivating perennial biomass crops on marginal lands,the regional total average daily precipitation increased by 6.33 mm/day(0.01%),with most of the increase occurring during spring,summer,and autumn in the central and western regions and during autumn and winter in the eastern region.This was primarily due to the significant enhancement of water vapor transport and latent heat flux in the region.The regional maximum daily precipitation decreased by 2.1 mm(4.39%),mainly in the central and eastern regions,Resulting from a significant decrease in sensible heat flux in these regions.Meanwhile,the frequency of precipitation events with an average daily precipitation greater than 50 mm/d decreased in the central and eastern regions,with the most pronounced reduction of 31 days(0.24%)observed in events in the range of 50.0~99.9 mm/day.[Conclusion]In summary,planting perennial biomass crops on marginal lands can increase regional precipitation and reduce extreme precipitation.These findings highlight the critical role of biophysical feedback mechanisms in regulating regional climate and provide a scientific foundation for developing climate-adaptive land management strategies.
