Topographic complexity supports the maintenance of a high diversity of microhabitats,which may act as important‘safe havens’-or microrefugia-for biodiversity.Microrefugia are sites with specific environmental condit...Topographic complexity supports the maintenance of a high diversity of microhabitats,which may act as important‘safe havens’-or microrefugia-for biodiversity.Microrefugia are sites with specific environmental conditions that facilitate the persistence of species during environmental changes and exhibit unique ecoevolutionary dynamics.However,our knowledge about how topographic complexity and related ecoevolutionary selective forces influence the functional and phylogenetic signatures of species assemblages in microrefugia is very limited.Although the conceptual framework on the systematic integration of plant functional traits into the study of refugia is well established,more empirical studies on functional trait composition and functional diversity in refugia are urgently needed for more effective conservation.Here we analyzed the distribution of various plant functional traits and phylogenetic patterns in microhabitats(south-and north-facing slopes,and bottoms)of 30 large topographic depressions(i.e.doline microrefugia)and microhabitats of the surrounding plateaus in two distant forested karst regions.We found that plant assemblages in the understory of dolines and their surroundings are characterized by unique functional values and combinations of traits.Doline bottoms had the highest functional diversity among doline microhabitats and supported plant assemblages with considerably different trait compositions from the plateaus.Bottoms also had the highest phylogenetic diversity.These results suggest that topographic complexity in forested dolines has a significant effect on the distribution of plant functional traits in the understory.High functional and phylogenetic diversity in doline bottoms can have important consequences for the long-term survival of plant populations,highlighting that these microhabitats may provide a higher resilience and support an adaptive community-level response to natural and anthropogenic stressors.Understanding mechanisms that drive the survival of species within microrefugia is required to determine the best conservation and management strategies.展开更多
Reasonable greening design can effectively alleviate campus heat environment issues.This study uses the ENVI-met numerical model,along with in-situ observations and simulations,to analyze the thermal environment under...Reasonable greening design can effectively alleviate campus heat environment issues.This study uses the ENVI-met numerical model,along with in-situ observations and simulations,to analyze the thermal environment under three different greening schemes in typical areas of the Guangzhou University campus.The results indicate that the outdoor thermal environment is significantly influenced by the underlying surface materials and vegetation.The temperature of brick-paved surface is 0.9℃higher than that of natural soil surfaces under tree shade.Numerical simulations further confirm that increasing vegetation coverage effectively reduces outdoor air temperature.When the greening rate increases to 40%,the outdoor average temperature decreases by 0.7℃and relative humidity increases by approximately 4%,while wind speed remains minimal change.The cooling effect of vegetation is found to extend vertically to an altitude of 13 m.As the greening rate increases from 15%to 40%,the Mean Radiant Temperature(MRT)decreases from 50.6℃to 28.9℃,which is lower than the average ambient temperature,indicating improved thermal conditions.The Physiological Equivalent Temperature(PET)decreases from 40.2℃to 30.0℃,with the proportion of the areas classified as″very hot″reducing by 36.8%,significantly improving thermal comfort across most areas.Therefore,changing the ground material and greening landscape design can effectively alter the outdoor wind and thermal environment of the campus,thereby enhancing the thermal comfort for the campus community.展开更多
Vegetation restoration is a critical strategy for mitigating debris flow hazards by stabilizing slopes and modifying hydrological processes.Effective planning of priority restoration areas is particularly essential in...Vegetation restoration is a critical strategy for mitigating debris flow hazards by stabilizing slopes and modifying hydrological processes.Effective planning of priority restoration areas is particularly essential in dry-hot valley regions,where extreme hydrothermal conditions pose significant challenges.This study presents a novel framework that integrates microclimatic variables,such as temperature lapse rates,to enhance the spatial precision of revegetation efforts.The Reshuihe watershed in Southwest China,a representative dry-hot valley,was chosen as the study area.By analyzing hourly temperature and rainfall across an elevation gradient,a quadratic relationship between temperature lapse rates and weak rainfall events was identified,underscoring the role of microclimatic processes in influencing rainfall distribution and plant-available water.Rainfall peaks were observed when the temperature lapse rate was approximately 4.5°C/km.This relationship was incorporated into a cost-based restoration framework using the Marxan model,optimizing the spatial allocation of priority areas for revegetation.Results demonstrated that integrating microclimatic variables significantly improved the effectiveness of revegetation strategies,particularly for reducing debris flow risks.The lowest restoration costs were observed between elevations of 3200 m and 3300 m,where strong correlations between temperature lapse rates and rainfall were recorded.Priority restoration areas covered 41 km^(2),targeting zones with high debris flow risks.These findings highlight the value of incorporating microclimatic data into revegetation planning,enabling cost-effective and ecologically sustainable hazard mitigation in regions vulnerable to hydrological hazards.展开更多
Urban underutilized spaces,often the secondary by-products of large infrastructure projects,are often overlooked,despite their potential to enhance city life.With meaningful design interventions,these neglected areas ...Urban underutilized spaces,often the secondary by-products of large infrastructure projects,are often overlooked,despite their potential to enhance city life.With meaningful design interventions,these neglected areas can be transformed into inclusive public environments that offer social,environmental,and cultural value.This research investigates how modular,temporary installations beneath Toronto’s Gardiner Expressway,in Canada,can enhance thermal comfort and foster community engagement during the shoulder seasons.Using a multi-step methodology,including literature review,thermal comfort guidelines,site-specific climate analysis,and precedent studies,the research identifies key design strategies tailored to the unique microclimatic and social conditions of under-bridge spaces.The study culminates in the proposal of a flexible system of movable panels that provide wind protection,solar control,and opportunities for gathering,interaction,and rest.By reimagining these unnoticed infrastructure zones as adaptable,climate-responsive public spaces,this research contributes to sustainable urban design and highlights the importance of design strategies that address the challenges of a warming and increasingly variable climate.展开更多
There is an urgent necessity to shift our diets toward those rich in fruits and vegetables and at reduce postharvest losses of perishables.Approximately 20%-50%of fruits and vegetables are lost due to poor postharvest...There is an urgent necessity to shift our diets toward those rich in fruits and vegetables and at reduce postharvest losses of perishables.Approximately 20%-50%of fruits and vegetables are lost due to poor postharvest handling and pathogen infections in developing countries while it was estimated as 5%-35%in developed countries. Fresh fruits have evolved with a plethora of microorganisms having important roles in maintaining fruit health. However, little information is available on the dynamics, structure, and functional capacities of underpinning fruit microbiomes. The present review discussed environmental conditions favoring fruit-harbored antagonists and their different modes of action for suppressing postharvest pathogens in fruits. It also provides information on omics technologies such as next-generation sequencing (NGS),metaproteomics, metatranscriptomic, and metabolomics studies to characterize fruit microbiomes. With the advent of NGS and meta-omics technologies, microbiome research could bring remarkable development and understanding in succeeding biological treatments. In addition, they may provide us with a fundamental understanding of microclimate requirements for fruit microbiome establishment and microbiome shifts during post-harvest storage, which would be advantageous in developing composite biocontrol treatments for post-harvest decay management.展开更多
Thermal comfort evaluations for Yuexiu Park,Lushan Park,and Baiyun Lake Park in Guangzhou were conducted using field meteorological data collection,visitor questionnaires,and literature reviews.It analyzed the impact ...Thermal comfort evaluations for Yuexiu Park,Lushan Park,and Baiyun Lake Park in Guangzhou were conducted using field meteorological data collection,visitor questionnaires,and literature reviews.It analyzed the impact of green coverage,water body layout,and facility configuration on thermal comfort.The results showed that good green and water body design effectively lowered the temperature in the park and improved the thermal comfort of visitors,but the insufficient facility configuration in some open areas affected the experience.The visitor’s experience is closely related to the natural environment and facility layout of the park.Therefore,in the future,park design should pay more attention to the rational configuration of shading,ventilation,and cooling facilities to improve thermal comfort,and encourage citizens to participate in the construction and management of parks to improve ecological quality and user experience.This study provides a reference for the improvement of thermal comfort in urban parks in Guangzhou and aims to promote the sustainable and human-oriented development of urban park design.展开更多
Although the importance of forest margins in ecology is recognized, no study has been carried out in the Slătioara Secular Forest Reserve with reference to the variability of abiotic parameters along forest margins. W...Although the importance of forest margins in ecology is recognized, no study has been carried out in the Slătioara Secular Forest Reserve with reference to the variability of abiotic parameters along forest margins. With this study, we investigate to what extent microclimatic variables (air temperature—T_air, air humidity—H_air, soil temperature—T_soil, soil humidity—H_soil wind intensity (WIND) and photosynthetically active radiation intensity (PAR)) are correlated with the distance from the edge to the forest interior and the habitat type (forest interior, inner and outer edge and meadow) in the Slătioara Secular Forest Reserve. In order to measure these microenvironment variables we used the strip transect method, positioned perpendicular to the forest edge. Differences in the microenvironment variables considered in the analysis between the four habitat types were assessed using one-way ANOVA followed by Tukey-test post-hoc. To assess differences along transects, each of the six measurements went through a one-way ANOVA against distance to edge, followed by a Levene’s test for variances and finally a Tukey-test post-hoc. The results indicate that the values of microclimatic variables were significantly different in relation to the gradient of distance from the edge and to the habitat type (interior-exterior forest) and that edge habitats are significantly more susceptible to lower humidity, high winds, lower light and higher air temperatures than forest interior habitats. The ecological study of the edge areas in this reserve provides the basis for future research on forest dynamics and can guide conservation efforts to maintain the diversity and endemism of species in the Slătioara Secular Forest.展开更多
Microclimate characteristics and related environmental energy mechanisms were examined based on the long term located observations in the mature, thinned and young Cunninghamia lanceolata plantation ecosystems in...Microclimate characteristics and related environmental energy mechanisms were examined based on the long term located observations in the mature, thinned and young Cunninghamia lanceolata plantation ecosystems in western Hunan Province, China. The results show that the mature plantation ecosystem can improve the microclimate significantly by regulating the amount and spatial distribution of environmental energy, which delineates the pattern of the microclimate in forest ecosystems in the process of ecological restoration. Compared with the young plantation, the mature plantation ecosystem decreased annual mean air temperature by 0 4℃. The maximum decrease in monthly mean air temperature was 2 3℃. The mature plantation ecosystem decreased annual mean ground temperature by 1 2℃ with a maximum decrease in monthly mean ground temperature of 2 3℃. Mainly due to the dense canopy, the mature forest ecosystem regulates the distribution of radiation energy, and expenditure ratios of heat budget and principal energy components to decrease temperature or make it even.展开更多
Objective The aim was to elucidate the effects of N rates on rice canopy microclimate and community health so as to provide a sci- entific basis for studying the production potential in irrigated rice with healthy can...Objective The aim was to elucidate the effects of N rates on rice canopy microclimate and community health so as to provide a sci- entific basis for studying the production potential in irrigated rice with healthy canopy. Method The effects of rice population structure traits under different N rates on rice canopy temperature, relative humidity （ RH）, light transmittance and sheath blight were studied by using Sunscan canopy analysis system and HOBO（ Pro Temp/RH IS logger）. Result The results showed that leaf area index, plant height and tiller number had significant effects on canopy cooling, RH enhancing and light reducing. Extremely significant multiple linear regression relationships existed among canopy day temperature, day RH, LAI and tiller number, and among light transmittance, tiller number and plant height. At flowering stage, per unit LAI could result in a day-maximum-temperature （Tmax） deceasing of 0.87℃ and a day-minimum-RH （RHmin） enhancing of 2.5% within canopy. Similarly, 100 plants per ms could respectively cause a Tmax deceasing of 1.23℃ and an RHmin enhancing of 3.3% in rice canopy. And per 10 cm plant height and 100 plants per m^2 could respectively reduce 9.3% and 7.8% of light in canopy. Conclusion Sheath blight disease index was significantly enhanced as the canopy day temperature decreased, day RH increased and light transmittance reduced. Bigger canopy from higher nitrogen level treatment leads to a more stable canopy microclimate with little changes in temperature and RH during day and night, which has the risk of worsening canopy health. Thus, moderately controlling the space development of canopy is the basis of constructing healthy canopy in rice.展开更多
Sod culture in peach orchards is an advanced soil management. The significances of sod culture in peach orchard are introduced, as well as the sod ways. The effects of sod culture in a peach orchard on soil, microclim...Sod culture in peach orchards is an advanced soil management. The significances of sod culture in peach orchard are introduced, as well as the sod ways. The effects of sod culture in a peach orchard on soil, microclimate and growth and development of peach tree, and disease, pest and weed are reviewed. The problems in sod culture in peach orchard in China are summarized. Sod culture could increase soil fertility, improve soil physical properties, relieve soil temperature change, increase soil microbial growth and soil enzyme activity, improve microclimate and fruit quality, reduce physiological disease, insect pests and weeds.展开更多
With urbanization encroaching upon forestlands, characterizing microclimates in secondary forests will be important for the sustainable management of microclimates in agroforestry systems. We used micro-sensors to cha...With urbanization encroaching upon forestlands, characterizing microclimates in secondary forests will be important for the sustainable management of microclimates in agroforestry systems. We used micro-sensors to characterize changes in temperature at different heights in the sub-canopy of both secondary forest and 15-year-old agroforestry plots. Results show that while agroforestry plots had different temperature profiles from the secondary forest, the monoculture plot (consisting of Pentaclethra macroloba) had temperatures similar to the profile found in the secondary forest. This suggests that the replication of temperature profiles in a secondary forest may be independent of the number of tree species in a plot (e.g. polyculture), but may instead depend on the density of a given trees species. These findings further suggest that characterizing temperature microclimates in secondary forests can serve to improve the ecological sustainability of agro-forestry systems.展开更多
Objective] This study aimed to explore the biological basis and microcli-mate effects in intercropping jujube orchard. [Method] From 2009 to 2011, jujube was intercroped with wheat, peanut, soybean, garlic, watermelon...Objective] This study aimed to explore the biological basis and microcli-mate effects in intercropping jujube orchard. [Method] From 2009 to 2011, jujube was intercroped with wheat, peanut, soybean, garlic, watermelon, vegetables etc. By fixed observation and simultaneous mobile observation, the field microclimate factors such as the air temperature, surface temperature, air relative humidity, wind speed, etc. were measured, with mono-crop farmland as the control. [Result] The competi-tion relationship existed between jujube trees and the intercropped plants for re-sources such as il umination, fertilizer, and water; however there were differences in phenological phases and the critical periods in needing for water, fertilizer and il u-mination between jujube and intercropped plants. Meanwhile, there was significant difference （P〈0.05） in the variation of agricultural microclimate environment in jujube field compared with that in control farmland. Compared with the control, the air tem-perature in intercropping jujube orchard was reduced by 0.2 to 0.7 ℃, the earth surface temperature reduction ranged from 2.1 to 2.5 ℃, the relative air humidity increased by 3.7% to 6.8% and the wind speed decreased by 0.2 to 0.4 m/s. [Conclusion] Al above results showed that intercropping in jujube orchard could be promoted in central China and northern China areas.展开更多
Maximum and minimum metabolic rates in birds are flexible traits and such flexibility can be advantageous in variable climates.The climatic variability hypothesis(CVH)posits that more variable climates should result i...Maximum and minimum metabolic rates in birds are flexible traits and such flexibility can be advantageous in variable climates.The climatic variability hypothesis(CVH)posits that more variable climates should result in greater metabolic flexibility for geographically distinct populations.Whether the CVH applies to sympatric species occupying microclimates differing in variability is unknown.Microclimates of open habitats are likely more variable than those of sheltered habitats.If the CVH extends to microclimates,we expect birds from open habitats to show greater flexibility than those from sheltered habitats.To test this extension of the CVH,we compared seasonal variation in microclimates and metabolic rates for sympatric horned larks Eremophila alpestris,which occupy open habitats,and house sparrows Passer domesticus,which occupy sheltered habitats.We measured operative temperature(T_(e′) an integrative measure of the thermal environment),summit metabolic rate(M_(sum′) maximal cold-induced metabolic rate),and basal metabolic rate(BMR,minimal maintenance metabolic rate)in summer and winter.For both winter and summer,daily minimum Te was similar between open and sheltered habitats but maximum Te was higher for open habitats.Winter microclimates,however,were colder for open than for sheltered habitats after accounting for convective differences.Both species increased M_(sum) in winter,but seasonal M_(sum) flexibility was greater for larks(43%)than for sparrows(31%).Winter increases in BMR were 92.5% and 11% for larks and sparrows,respectively,with only the former attaining statistical significance.Moreover,species*season interactions in general linear models for whole-organism metabolic rates were significant for BMR and showed a similar,although not significant,pattern for M_(sum),with greater seasonal metabolic flexibility in horned larks than in house sparrows.These results suggest that extending the CVH to sympatric bird species occupying different microclimates may be valid.展开更多
In order to improve the understanding of the role of a canopy opening/gap on the physical environments in a secondary forest in Northeastern China, a case study was conducted in and around a small irregular gap in a m...In order to improve the understanding of the role of a canopy opening/gap on the physical environments in a secondary forest in Northeastern China, a case study was conducted in and around a small irregular gap in a montane secondary forest. The secondary forest, which was severely disturbed by human beings about 50 years ago, was dominated by Quercus mongolica and Fraxinus rhynchophyllaan. Temporal variation in photosynthetic photon flux density （PPFD）, air temperature （TA） at 10 cm above the ground, soil temperature （Ts） and soil water content （SWC） at top-layer （0-15 cm） and sub-layer （15-30 cm） were measured from May to September after the second year since the formation of the small gap （the ratios of gap diameter to stand height were less than 0.5） in 2006 respectively. Results indicated that the highest value of PPFD occurred at the northern edge of the gap, particularly at the beginning of the growing season in May. On sunny days, the highest value of PPFD appeared earlier than that on overcast days. Maximum and mean values of TAwere higher in the northern part of the gap, and the minimum values of TAwere at the southern edge of the gap. Soil temperature varied obviously in the gap with the range from 1 to 8 ℃. Maximum values of Ts occurred at the northern part of the gap, which was significantly correlated with the maximum values of TA （R = 0.735, P〈0.05）. SWC was higher in the top-layer （0-15 cm） than that in sub-layer （15-30 cm）, but the difference of them was not significant （p〉0.05）, which might be attributed to the small gap size and the effects of aboveground vegetations. From these results, the maximum of PPFD in the study area occurred at the northern part of the gap, which was consistent with the results observed in north hemisphere, but the occurrence time varied with the differences of the latitudes. The highest values of air and soil temperatures also occurred in the northern part of the gap because they were affected by the radiation. However, the variation of temperature in July was different from other months due to the influence of gap size. And the values of soil water content were neither higher in the gap in the wet season nor lower in the dry season, which might be affected by the gap size and topography the gap located. The variations of light, soil and air temperatures, and soil moisture in this small irregular gap might be related to the effects of the micro-site, which affects the regeneration of plant species.展开更多
Ecosystems in high-altitude regions are more sensitive and respond more rapidly than other ecosystems to global climate warming.The Qinghai-Tibet Plateau(QTP)of China is an ecologically fragile zone that is sensitive ...Ecosystems in high-altitude regions are more sensitive and respond more rapidly than other ecosystems to global climate warming.The Qinghai-Tibet Plateau(QTP)of China is an ecologically fragile zone that is sensitive to global climate warming.It is of great importance to study the changes in aboveground biomass and species diversity of alpine meadows on the QTP under predicted future climate warming.In this study,we selected an alpine meadow on the QTP as the study object and used infrared radiators as the warming device for a simulation experiment over eight years(2011-2018).We then analyzed the dynamic changes in aboveground biomass and species diversity of the alpine meadow at different time scales,including an early stage of warming(2011-2013)and a late stage of warming(2016-2018),in order to explore the response of alpine meadows to short-term(three years)and long-term warming(eight years).The results showed that the short-term warming increased air temperature by 0.31℃and decreased relative humidity by 2.54%,resulting in the air being warmer and drier.The long-term warming increased air temperature and relative humidity by 0.19℃and 1.47%,respectively,and the air tended to be warmer and wetter.The short-term warming increased soil temperature by 2.44℃and decreased soil moisture by 12.47%,whereas the long-term warming increased soil temperature by 1.76℃and decreased soil moisture by 9.90%.This caused the shallow soil layer to become warmer and drier under both short-term and long-term warming.Furthermore,the degree of soil drought was alleviated with increased warming duration.Under the long-term warming,the importance value and aboveground biomass of plants in different families changed.The importance values of grasses and sedges decreased by 47.56%and 3.67%,respectively,while the importance value of weeds increased by 1.37%.Aboveground biomass of grasses decreased by 36.55%,while those of sedges and weeds increased by 8.09%and 15.24%,respectively.The increase in temperature had a non-significant effect on species diversity.The species diversity indices increased at the early stage of warming and decreased at the late stage of warming,but none of them reached significant levels(P>0.05).Species diversity had no significant correlation with soil temperature and soil moisture under both short-term and long-term warming.Soil temperature and aboveground biomass were positively correlated in the control plots(P=0.014),but negatively correlated under the long-term warming(P=0.013).Therefore,eight years of warming aggravated drought in the shallow soil layer,which is beneficial for the growth of weeds but not for the growth of grasses.Warming changed the structure of alpine meadow communities and had a certain impact on the community species diversity.Our studies have great significance for the protection and effective utilization of alpine vegetation,as well as for the prevention of grassland degradation or desertification in high-altitude regions.展开更多
Sheath blight, a disease caused by the fungus Rhizoctonia solani Kuhn （anamorph）, has been the most economically significant disease of rice. It was frequently reported that the disease was well-controlled in integr...Sheath blight, a disease caused by the fungus Rhizoctonia solani Kuhn （anamorph）, has been the most economically significant disease of rice. It was frequently reported that the disease was well-controlled in integrated rice-duck system without the employment of fungicides. However, the effecting factors behind this phenomenon were rarely reported. In this research, experiment was carried out between two treatments, rice combined with ducks （RD） and conventional rice field without ducks rearing （CK） in early season rice paddy, to investigate the variations of sclerotia in floodwater and on rice plant, microclimate 10 cm above the waterline in rice paddy and activity of protective enzymes in rice plants. The results showed that the floating sclerotia in floodwater in RD was 86-91% lower than that in CK, and adhering sclerotia in rice plant in RD was 67-78% lower than that in CK. The relative humidity tested significantly lower and light intensity tested significantly higher in RD. The temperature in the early rice growth stages in RD was slightly lower than that in CK, but it was significantly higher （32.3-36.5~C） in the middle stage rice growth stages. The polyphenoloxidase （PPO） activity in RD were lower than that in CK, but the enhanced activity of phenylalanine ammonia-lyase （PAL）, peroxidase （POD） and Chitinase was observed in different stages of rice growth in RD, especially the Chitinase which showed higher activity in all investigating days.展开更多
The effects of mulching mode on population physiology and ecology of rice were studied using a combination P88S/1128 as the material under three mulching cultivation modes including plastic film mulching, straw mulchi...The effects of mulching mode on population physiology and ecology of rice were studied using a combination P88S/1128 as the material under three mulching cultivation modes including plastic film mulching, straw mulching and liquid film mulching, as well as bare cultivation (control). The results indicated that mulching mode had significant effects on micro-meteorological factors and individual growth of rice, as shown by an increase of relative humidity, a better internal micro-meteorological environment of rice population, a significant reduction under the rice canopy temperature, especially during high-temperature periods. Rice plants under mulching cultivation conditions displayed a stronger transpiration and lower leaf temperature, thereby improving the ability of anti-high temperature stress and markedly increasing the photosynthetic rate. Furthermore, the yield components of rice were significantly optimized under mulching cultivation, of which with plastic film mulching displayed the highest grain number per panicle and seed-setting rate, and a yield increase of 16.81% compared with the control; and with straw mulching displayed an increase of effective panicle number and a 9.59% increase of total yield compared to the control.展开更多
The microclimate of a desert oasis in hyperarid zone of China was monitored using micrometeorological methods and compared with those of areas adjacent to forested land. Differences in ground-level photosynthetically ...The microclimate of a desert oasis in hyperarid zone of China was monitored using micrometeorological methods and compared with those of areas adjacent to forested land. Differences in ground-level photosynthetically active radiation （PAR） on clear, cloudy and dust storm days and their subtending causes are analysed and discussed. Desert oases serve the ecological functions of altering solar radiation, adjusting near-ground and land surface temperatures, reducing soil temperature differences, lowering wind velocity, and increasing soil and atmospheric humidity. The total solar radiation in the interior of the oasis was roughly half of that outside a forest canopy. During the growing season, air temperatures in Populus euphratica Oliv. （poplar） and Tamarix ramosissima Ledeb. （tamarisk） forests were 1.62℃ and 0.83 ℃ lower respectively than those in the areas around the forests. Furthermore, the miler the forest cover, the greater the temperature drops; air temperatures in the upper storey were greater than those in the lower storey, i.e., air temperature rose with increasing height. Over the growing season, the relative humidities of the air in the poplar and tamarisk forests were 8.5% and 4.2% higher respectively than those in areas around the forests. Mean wind velocity in poplar-forested lands was 0.33 m·s^-1, 2.31 m·s^-1 lower than that in the surrounding area. During dust storm days the PAR was significantly lower than that on cloudy or clear days, when it was high and varied in an irregular manner.展开更多
To better understand the cooling effect of raingarden in Fitzroy Gardens, Melbourne, as well as it benefits for an urban microclimate, two rounds of 36-h microclimate monitoring at the raingarden were conducted.Land s...To better understand the cooling effect of raingarden in Fitzroy Gardens, Melbourne, as well as it benefits for an urban microclimate, two rounds of 36-h microclimate monitoring at the raingarden were conducted.Land surface temperature and soil moisture were analyzed according to monitoring data. The results showa clea raingarden cooling effect in summer. The largest difference o land surface temperatures inside and outside the raingarden can reach 23. 6 ℃, and the diurnal variation in temperature insid the raingarden was much less than that outside the raingarden.The soil moisture increased rapidly after irrigation, with th increase in the volumetric water content( VWC) of 2% to3. 6%. The soil moistures of adjacent irrigated garden bed and grass were higher than those inside the raingarden.Monitoring soil moisture helps guide raingarden irrigation.展开更多
基金funded by the National Research,Development and Innovation Office(NKFIH FK 142428 grant)The contribution of Z.B.was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences and by the New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research,Development and Innovation Fund(ÚNKP-23-5-SZTE-697)+2 种基金K.F.was supported by the New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research,Development and Innovation Fund(ÚNKP-23-3-SZTE-441)C.T.was supported by the NKFIH K 146137 grantA.E-V.was supported by the long-term research development project of the Czech Academy of Sciences(RVO 67985939).
文摘Topographic complexity supports the maintenance of a high diversity of microhabitats,which may act as important‘safe havens’-or microrefugia-for biodiversity.Microrefugia are sites with specific environmental conditions that facilitate the persistence of species during environmental changes and exhibit unique ecoevolutionary dynamics.However,our knowledge about how topographic complexity and related ecoevolutionary selective forces influence the functional and phylogenetic signatures of species assemblages in microrefugia is very limited.Although the conceptual framework on the systematic integration of plant functional traits into the study of refugia is well established,more empirical studies on functional trait composition and functional diversity in refugia are urgently needed for more effective conservation.Here we analyzed the distribution of various plant functional traits and phylogenetic patterns in microhabitats(south-and north-facing slopes,and bottoms)of 30 large topographic depressions(i.e.doline microrefugia)and microhabitats of the surrounding plateaus in two distant forested karst regions.We found that plant assemblages in the understory of dolines and their surroundings are characterized by unique functional values and combinations of traits.Doline bottoms had the highest functional diversity among doline microhabitats and supported plant assemblages with considerably different trait compositions from the plateaus.Bottoms also had the highest phylogenetic diversity.These results suggest that topographic complexity in forested dolines has a significant effect on the distribution of plant functional traits in the understory.High functional and phylogenetic diversity in doline bottoms can have important consequences for the long-term survival of plant populations,highlighting that these microhabitats may provide a higher resilience and support an adaptive community-level response to natural and anthropogenic stressors.Understanding mechanisms that drive the survival of species within microrefugia is required to determine the best conservation and management strategies.
基金Science and Technology Research Project of Guang-dong Meteorological Bureau(GRMC2022M21)Guangdong Basic and Applied Basic Research Foundation(2023A1515012240)Research Project of Guangzhou Meteor-ological Bureau(M202218)。
文摘Reasonable greening design can effectively alleviate campus heat environment issues.This study uses the ENVI-met numerical model,along with in-situ observations and simulations,to analyze the thermal environment under three different greening schemes in typical areas of the Guangzhou University campus.The results indicate that the outdoor thermal environment is significantly influenced by the underlying surface materials and vegetation.The temperature of brick-paved surface is 0.9℃higher than that of natural soil surfaces under tree shade.Numerical simulations further confirm that increasing vegetation coverage effectively reduces outdoor air temperature.When the greening rate increases to 40%,the outdoor average temperature decreases by 0.7℃and relative humidity increases by approximately 4%,while wind speed remains minimal change.The cooling effect of vegetation is found to extend vertically to an altitude of 13 m.As the greening rate increases from 15%to 40%,the Mean Radiant Temperature(MRT)decreases from 50.6℃to 28.9℃,which is lower than the average ambient temperature,indicating improved thermal conditions.The Physiological Equivalent Temperature(PET)decreases from 40.2℃to 30.0℃,with the proportion of the areas classified as″very hot″reducing by 36.8%,significantly improving thermal comfort across most areas.Therefore,changing the ground material and greening landscape design can effectively alter the outdoor wind and thermal environment of the campus,thereby enhancing the thermal comfort for the campus community.
基金supported by the National Natural Science Foundation of China for General Program(42171118)the National Natural Science Foundation of China for Distinguished Young Scholars(41925030)the Special Funding Projects of Talents of Yunnan Province(YNWR-QNBJ-2020-099).
文摘Vegetation restoration is a critical strategy for mitigating debris flow hazards by stabilizing slopes and modifying hydrological processes.Effective planning of priority restoration areas is particularly essential in dry-hot valley regions,where extreme hydrothermal conditions pose significant challenges.This study presents a novel framework that integrates microclimatic variables,such as temperature lapse rates,to enhance the spatial precision of revegetation efforts.The Reshuihe watershed in Southwest China,a representative dry-hot valley,was chosen as the study area.By analyzing hourly temperature and rainfall across an elevation gradient,a quadratic relationship between temperature lapse rates and weak rainfall events was identified,underscoring the role of microclimatic processes in influencing rainfall distribution and plant-available water.Rainfall peaks were observed when the temperature lapse rate was approximately 4.5°C/km.This relationship was incorporated into a cost-based restoration framework using the Marxan model,optimizing the spatial allocation of priority areas for revegetation.Results demonstrated that integrating microclimatic variables significantly improved the effectiveness of revegetation strategies,particularly for reducing debris flow risks.The lowest restoration costs were observed between elevations of 3200 m and 3300 m,where strong correlations between temperature lapse rates and rainfall were recorded.Priority restoration areas covered 41 km^(2),targeting zones with high debris flow risks.These findings highlight the value of incorporating microclimatic data into revegetation planning,enabling cost-effective and ecologically sustainable hazard mitigation in regions vulnerable to hydrological hazards.
文摘Urban underutilized spaces,often the secondary by-products of large infrastructure projects,are often overlooked,despite their potential to enhance city life.With meaningful design interventions,these neglected areas can be transformed into inclusive public environments that offer social,environmental,and cultural value.This research investigates how modular,temporary installations beneath Toronto’s Gardiner Expressway,in Canada,can enhance thermal comfort and foster community engagement during the shoulder seasons.Using a multi-step methodology,including literature review,thermal comfort guidelines,site-specific climate analysis,and precedent studies,the research identifies key design strategies tailored to the unique microclimatic and social conditions of under-bridge spaces.The study culminates in the proposal of a flexible system of movable panels that provide wind protection,solar control,and opportunities for gathering,interaction,and rest.By reimagining these unnoticed infrastructure zones as adaptable,climate-responsive public spaces,this research contributes to sustainable urban design and highlights the importance of design strategies that address the challenges of a warming and increasingly variable climate.
基金the Deanship of Scientific Research,King Faisal University,Saudi Arabia(Grant No.5067).
文摘There is an urgent necessity to shift our diets toward those rich in fruits and vegetables and at reduce postharvest losses of perishables.Approximately 20%-50%of fruits and vegetables are lost due to poor postharvest handling and pathogen infections in developing countries while it was estimated as 5%-35%in developed countries. Fresh fruits have evolved with a plethora of microorganisms having important roles in maintaining fruit health. However, little information is available on the dynamics, structure, and functional capacities of underpinning fruit microbiomes. The present review discussed environmental conditions favoring fruit-harbored antagonists and their different modes of action for suppressing postharvest pathogens in fruits. It also provides information on omics technologies such as next-generation sequencing (NGS),metaproteomics, metatranscriptomic, and metabolomics studies to characterize fruit microbiomes. With the advent of NGS and meta-omics technologies, microbiome research could bring remarkable development and understanding in succeeding biological treatments. In addition, they may provide us with a fundamental understanding of microclimate requirements for fruit microbiome establishment and microbiome shifts during post-harvest storage, which would be advantageous in developing composite biocontrol treatments for post-harvest decay management.
文摘Thermal comfort evaluations for Yuexiu Park,Lushan Park,and Baiyun Lake Park in Guangzhou were conducted using field meteorological data collection,visitor questionnaires,and literature reviews.It analyzed the impact of green coverage,water body layout,and facility configuration on thermal comfort.The results showed that good green and water body design effectively lowered the temperature in the park and improved the thermal comfort of visitors,but the insufficient facility configuration in some open areas affected the experience.The visitor’s experience is closely related to the natural environment and facility layout of the park.Therefore,in the future,park design should pay more attention to the rational configuration of shading,ventilation,and cooling facilities to improve thermal comfort,and encourage citizens to participate in the construction and management of parks to improve ecological quality and user experience.This study provides a reference for the improvement of thermal comfort in urban parks in Guangzhou and aims to promote the sustainable and human-oriented development of urban park design.
文摘Although the importance of forest margins in ecology is recognized, no study has been carried out in the Slătioara Secular Forest Reserve with reference to the variability of abiotic parameters along forest margins. With this study, we investigate to what extent microclimatic variables (air temperature—T_air, air humidity—H_air, soil temperature—T_soil, soil humidity—H_soil wind intensity (WIND) and photosynthetically active radiation intensity (PAR)) are correlated with the distance from the edge to the forest interior and the habitat type (forest interior, inner and outer edge and meadow) in the Slătioara Secular Forest Reserve. In order to measure these microenvironment variables we used the strip transect method, positioned perpendicular to the forest edge. Differences in the microenvironment variables considered in the analysis between the four habitat types were assessed using one-way ANOVA followed by Tukey-test post-hoc. To assess differences along transects, each of the six measurements went through a one-way ANOVA against distance to edge, followed by a Levene’s test for variances and finally a Tukey-test post-hoc. The results indicate that the values of microclimatic variables were significantly different in relation to the gradient of distance from the edge and to the habitat type (interior-exterior forest) and that edge habitats are significantly more susceptible to lower humidity, high winds, lower light and higher air temperatures than forest interior habitats. The ecological study of the edge areas in this reserve provides the basis for future research on forest dynamics and can guide conservation efforts to maintain the diversity and endemism of species in the Slătioara Secular Forest.
文摘Microclimate characteristics and related environmental energy mechanisms were examined based on the long term located observations in the mature, thinned and young Cunninghamia lanceolata plantation ecosystems in western Hunan Province, China. The results show that the mature plantation ecosystem can improve the microclimate significantly by regulating the amount and spatial distribution of environmental energy, which delineates the pattern of the microclimate in forest ecosystems in the process of ecological restoration. Compared with the young plantation, the mature plantation ecosystem decreased annual mean air temperature by 0 4℃. The maximum decrease in monthly mean air temperature was 2 3℃. The mature plantation ecosystem decreased annual mean ground temperature by 1 2℃ with a maximum decrease in monthly mean ground temperature of 2 3℃. Mainly due to the dense canopy, the mature forest ecosystem regulates the distribution of radiation energy, and expenditure ratios of heat budget and principal energy components to decrease temperature or make it even.
基金Supported by Oversea Project of National Natural and Science Foundationof China(30528005)RTOP Project of International RiceResearch Institute(IRRI)+1 种基金Grain High-yield Project of China(2004BA520A12)And 948 Introduction Project of the Ministry ofAgriculture(2003-Z53)~~
文摘Objective The aim was to elucidate the effects of N rates on rice canopy microclimate and community health so as to provide a sci- entific basis for studying the production potential in irrigated rice with healthy canopy. Method The effects of rice population structure traits under different N rates on rice canopy temperature, relative humidity （ RH）, light transmittance and sheath blight were studied by using Sunscan canopy analysis system and HOBO（ Pro Temp/RH IS logger）. Result The results showed that leaf area index, plant height and tiller number had significant effects on canopy cooling, RH enhancing and light reducing. Extremely significant multiple linear regression relationships existed among canopy day temperature, day RH, LAI and tiller number, and among light transmittance, tiller number and plant height. At flowering stage, per unit LAI could result in a day-maximum-temperature （Tmax） deceasing of 0.87℃ and a day-minimum-RH （RHmin） enhancing of 2.5% within canopy. Similarly, 100 plants per ms could respectively cause a Tmax deceasing of 1.23℃ and an RHmin enhancing of 3.3% in rice canopy. And per 10 cm plant height and 100 plants per m^2 could respectively reduce 9.3% and 7.8% of light in canopy. Conclusion Sheath blight disease index was significantly enhanced as the canopy day temperature decreased, day RH increased and light transmittance reduced. Bigger canopy from higher nitrogen level treatment leads to a more stable canopy microclimate with little changes in temperature and RH during day and night, which has the risk of worsening canopy health. Thus, moderately controlling the space development of canopy is the basis of constructing healthy canopy in rice.
文摘Sod culture in peach orchards is an advanced soil management. The significances of sod culture in peach orchard are introduced, as well as the sod ways. The effects of sod culture in a peach orchard on soil, microclimate and growth and development of peach tree, and disease, pest and weed are reviewed. The problems in sod culture in peach orchard in China are summarized. Sod culture could increase soil fertility, improve soil physical properties, relieve soil temperature change, increase soil microbial growth and soil enzyme activity, improve microclimate and fruit quality, reduce physiological disease, insect pests and weeds.
文摘With urbanization encroaching upon forestlands, characterizing microclimates in secondary forests will be important for the sustainable management of microclimates in agroforestry systems. We used micro-sensors to characterize changes in temperature at different heights in the sub-canopy of both secondary forest and 15-year-old agroforestry plots. Results show that while agroforestry plots had different temperature profiles from the secondary forest, the monoculture plot (consisting of Pentaclethra macroloba) had temperatures similar to the profile found in the secondary forest. This suggests that the replication of temperature profiles in a secondary forest may be independent of the number of tree species in a plot (e.g. polyculture), but may instead depend on the density of a given trees species. These findings further suggest that characterizing temperature microclimates in secondary forests can serve to improve the ecological sustainability of agro-forestry systems.
基金Supported by Science and Technology Development Program of Department of Science and Technology of Henan Province(2006220001)~~
文摘Objective] This study aimed to explore the biological basis and microcli-mate effects in intercropping jujube orchard. [Method] From 2009 to 2011, jujube was intercroped with wheat, peanut, soybean, garlic, watermelon, vegetables etc. By fixed observation and simultaneous mobile observation, the field microclimate factors such as the air temperature, surface temperature, air relative humidity, wind speed, etc. were measured, with mono-crop farmland as the control. [Result] The competi-tion relationship existed between jujube trees and the intercropped plants for re-sources such as il umination, fertilizer, and water; however there were differences in phenological phases and the critical periods in needing for water, fertilizer and il u-mination between jujube and intercropped plants. Meanwhile, there was significant difference （P〈0.05） in the variation of agricultural microclimate environment in jujube field compared with that in control farmland. Compared with the control, the air tem-perature in intercropping jujube orchard was reduced by 0.2 to 0.7 ℃, the earth surface temperature reduction ranged from 2.1 to 2.5 ℃, the relative air humidity increased by 3.7% to 6.8% and the wind speed decreased by 0.2 to 0.4 m/s. [Conclusion] Al above results showed that intercropping in jujube orchard could be promoted in central China and northern China areas.
文摘Maximum and minimum metabolic rates in birds are flexible traits and such flexibility can be advantageous in variable climates.The climatic variability hypothesis(CVH)posits that more variable climates should result in greater metabolic flexibility for geographically distinct populations.Whether the CVH applies to sympatric species occupying microclimates differing in variability is unknown.Microclimates of open habitats are likely more variable than those of sheltered habitats.If the CVH extends to microclimates,we expect birds from open habitats to show greater flexibility than those from sheltered habitats.To test this extension of the CVH,we compared seasonal variation in microclimates and metabolic rates for sympatric horned larks Eremophila alpestris,which occupy open habitats,and house sparrows Passer domesticus,which occupy sheltered habitats.We measured operative temperature(T_(e′) an integrative measure of the thermal environment),summit metabolic rate(M_(sum′) maximal cold-induced metabolic rate),and basal metabolic rate(BMR,minimal maintenance metabolic rate)in summer and winter.For both winter and summer,daily minimum Te was similar between open and sheltered habitats but maximum Te was higher for open habitats.Winter microclimates,however,were colder for open than for sheltered habitats after accounting for convective differences.Both species increased M_(sum) in winter,but seasonal M_(sum) flexibility was greater for larks(43%)than for sparrows(31%).Winter increases in BMR were 92.5% and 11% for larks and sparrows,respectively,with only the former attaining statistical significance.Moreover,species*season interactions in general linear models for whole-organism metabolic rates were significant for BMR and showed a similar,although not significant,pattern for M_(sum),with greater seasonal metabolic flexibility in horned larks than in house sparrows.These results suggest that extending the CVH to sympatric bird species occupying different microclimates may be valid.
基金This research was supported by National Natural Science Foundation of China （30671669） and ＂the 100-Young-Researcher Project＂ of Chinese,Academy of Sciences.
文摘In order to improve the understanding of the role of a canopy opening/gap on the physical environments in a secondary forest in Northeastern China, a case study was conducted in and around a small irregular gap in a montane secondary forest. The secondary forest, which was severely disturbed by human beings about 50 years ago, was dominated by Quercus mongolica and Fraxinus rhynchophyllaan. Temporal variation in photosynthetic photon flux density （PPFD）, air temperature （TA） at 10 cm above the ground, soil temperature （Ts） and soil water content （SWC） at top-layer （0-15 cm） and sub-layer （15-30 cm） were measured from May to September after the second year since the formation of the small gap （the ratios of gap diameter to stand height were less than 0.5） in 2006 respectively. Results indicated that the highest value of PPFD occurred at the northern edge of the gap, particularly at the beginning of the growing season in May. On sunny days, the highest value of PPFD appeared earlier than that on overcast days. Maximum and mean values of TAwere higher in the northern part of the gap, and the minimum values of TAwere at the southern edge of the gap. Soil temperature varied obviously in the gap with the range from 1 to 8 ℃. Maximum values of Ts occurred at the northern part of the gap, which was significantly correlated with the maximum values of TA （R = 0.735, P〈0.05）. SWC was higher in the top-layer （0-15 cm） than that in sub-layer （15-30 cm）, but the difference of them was not significant （p〉0.05）, which might be attributed to the small gap size and the effects of aboveground vegetations. From these results, the maximum of PPFD in the study area occurred at the northern part of the gap, which was consistent with the results observed in north hemisphere, but the occurrence time varied with the differences of the latitudes. The highest values of air and soil temperatures also occurred in the northern part of the gap because they were affected by the radiation. However, the variation of temperature in July was different from other months due to the influence of gap size. And the values of soil water content were neither higher in the gap in the wet season nor lower in the dry season, which might be affected by the gap size and topography the gap located. The variations of light, soil and air temperatures, and soil moisture in this small irregular gap might be related to the effects of the micro-site, which affects the regeneration of plant species.
基金This study was financially supported by the National Natural Science Foundation of China(41501219)the Applied Basic Research Project of Shanxi Province(2016021136)+2 种基金the National College Students'Innovative Entrepreneurial Training Plan Program of China(201910119007)the Research Project of Philosophy and Social Sciences in Colleges and Universities of Shanxi Province(2019W134)the Soft Science Research Project of Shanxi Province(2018041072-1).
文摘Ecosystems in high-altitude regions are more sensitive and respond more rapidly than other ecosystems to global climate warming.The Qinghai-Tibet Plateau(QTP)of China is an ecologically fragile zone that is sensitive to global climate warming.It is of great importance to study the changes in aboveground biomass and species diversity of alpine meadows on the QTP under predicted future climate warming.In this study,we selected an alpine meadow on the QTP as the study object and used infrared radiators as the warming device for a simulation experiment over eight years(2011-2018).We then analyzed the dynamic changes in aboveground biomass and species diversity of the alpine meadow at different time scales,including an early stage of warming(2011-2013)and a late stage of warming(2016-2018),in order to explore the response of alpine meadows to short-term(three years)and long-term warming(eight years).The results showed that the short-term warming increased air temperature by 0.31℃and decreased relative humidity by 2.54%,resulting in the air being warmer and drier.The long-term warming increased air temperature and relative humidity by 0.19℃and 1.47%,respectively,and the air tended to be warmer and wetter.The short-term warming increased soil temperature by 2.44℃and decreased soil moisture by 12.47%,whereas the long-term warming increased soil temperature by 1.76℃and decreased soil moisture by 9.90%.This caused the shallow soil layer to become warmer and drier under both short-term and long-term warming.Furthermore,the degree of soil drought was alleviated with increased warming duration.Under the long-term warming,the importance value and aboveground biomass of plants in different families changed.The importance values of grasses and sedges decreased by 47.56%and 3.67%,respectively,while the importance value of weeds increased by 1.37%.Aboveground biomass of grasses decreased by 36.55%,while those of sedges and weeds increased by 8.09%and 15.24%,respectively.The increase in temperature had a non-significant effect on species diversity.The species diversity indices increased at the early stage of warming and decreased at the late stage of warming,but none of them reached significant levels(P>0.05).Species diversity had no significant correlation with soil temperature and soil moisture under both short-term and long-term warming.Soil temperature and aboveground biomass were positively correlated in the control plots(P=0.014),but negatively correlated under the long-term warming(P=0.013).Therefore,eight years of warming aggravated drought in the shallow soil layer,which is beneficial for the growth of weeds but not for the growth of grasses.Warming changed the structure of alpine meadow communities and had a certain impact on the community species diversity.Our studies have great significance for the protection and effective utilization of alpine vegetation,as well as for the prevention of grassland degradation or desertification in high-altitude regions.
基金the National Natural Science Foundation of China (31070397)
文摘Sheath blight, a disease caused by the fungus Rhizoctonia solani Kuhn （anamorph）, has been the most economically significant disease of rice. It was frequently reported that the disease was well-controlled in integrated rice-duck system without the employment of fungicides. However, the effecting factors behind this phenomenon were rarely reported. In this research, experiment was carried out between two treatments, rice combined with ducks （RD） and conventional rice field without ducks rearing （CK） in early season rice paddy, to investigate the variations of sclerotia in floodwater and on rice plant, microclimate 10 cm above the waterline in rice paddy and activity of protective enzymes in rice plants. The results showed that the floating sclerotia in floodwater in RD was 86-91% lower than that in CK, and adhering sclerotia in rice plant in RD was 67-78% lower than that in CK. The relative humidity tested significantly lower and light intensity tested significantly higher in RD. The temperature in the early rice growth stages in RD was slightly lower than that in CK, but it was significantly higher （32.3-36.5~C） in the middle stage rice growth stages. The polyphenoloxidase （PPO） activity in RD were lower than that in CK, but the enhanced activity of phenylalanine ammonia-lyase （PAL）, peroxidase （POD） and Chitinase was observed in different stages of rice growth in RD, especially the Chitinase which showed higher activity in all investigating days.
基金supported by the Major Science and Technology Capture Project in the Eleventh Five-Year Plan in Hunan Province, China titled 'Super high yielding hybrid rice cultivation technology research and demonstration'the National Great Science and Technology Support Plan, Chinathe National Science and Technology Project for Food Production, China
文摘The effects of mulching mode on population physiology and ecology of rice were studied using a combination P88S/1128 as the material under three mulching cultivation modes including plastic film mulching, straw mulching and liquid film mulching, as well as bare cultivation (control). The results indicated that mulching mode had significant effects on micro-meteorological factors and individual growth of rice, as shown by an increase of relative humidity, a better internal micro-meteorological environment of rice population, a significant reduction under the rice canopy temperature, especially during high-temperature periods. Rice plants under mulching cultivation conditions displayed a stronger transpiration and lower leaf temperature, thereby improving the ability of anti-high temperature stress and markedly increasing the photosynthetic rate. Furthermore, the yield components of rice were significantly optimized under mulching cultivation, of which with plastic film mulching displayed the highest grain number per panicle and seed-setting rate, and a yield increase of 16.81% compared with the control; and with straw mulching displayed an increase of effective panicle number and a 9.59% increase of total yield compared to the control.
基金The Hundred Talent Foundation, No.2003401Knowledge Innovation Project of Chinese Academy of Sciences, No.KZCX3-SW-329
文摘The microclimate of a desert oasis in hyperarid zone of China was monitored using micrometeorological methods and compared with those of areas adjacent to forested land. Differences in ground-level photosynthetically active radiation （PAR） on clear, cloudy and dust storm days and their subtending causes are analysed and discussed. Desert oases serve the ecological functions of altering solar radiation, adjusting near-ground and land surface temperatures, reducing soil temperature differences, lowering wind velocity, and increasing soil and atmospheric humidity. The total solar radiation in the interior of the oasis was roughly half of that outside a forest canopy. During the growing season, air temperatures in Populus euphratica Oliv. （poplar） and Tamarix ramosissima Ledeb. （tamarisk） forests were 1.62℃ and 0.83 ℃ lower respectively than those in the areas around the forests. Furthermore, the miler the forest cover, the greater the temperature drops; air temperatures in the upper storey were greater than those in the lower storey, i.e., air temperature rose with increasing height. Over the growing season, the relative humidities of the air in the poplar and tamarisk forests were 8.5% and 4.2% higher respectively than those in areas around the forests. Mean wind velocity in poplar-forested lands was 0.33 m·s^-1, 2.31 m·s^-1 lower than that in the surrounding area. During dust storm days the PAR was significantly lower than that on cloudy or clear days, when it was high and varied in an irregular manner.
基金The Natural Science Foundation of Jiangsu Province(No.BK20170682)the Fundamental Research Funds for the Central Universities(No.2242014R20004)Jiangsu Planned Projects for Postdoctoral Research Funds(No.1302098C)
文摘To better understand the cooling effect of raingarden in Fitzroy Gardens, Melbourne, as well as it benefits for an urban microclimate, two rounds of 36-h microclimate monitoring at the raingarden were conducted.Land surface temperature and soil moisture were analyzed according to monitoring data. The results showa clea raingarden cooling effect in summer. The largest difference o land surface temperatures inside and outside the raingarden can reach 23. 6 ℃, and the diurnal variation in temperature insid the raingarden was much less than that outside the raingarden.The soil moisture increased rapidly after irrigation, with th increase in the volumetric water content( VWC) of 2% to3. 6%. The soil moistures of adjacent irrigated garden bed and grass were higher than those inside the raingarden.Monitoring soil moisture helps guide raingarden irrigation.
