Earthworms exhibit distinct biological traits contributing to ecosystem resilience.As a keystone species of terrestrial ecosystem,they influence soil health.This study investigates the transformation of bacterial popu...Earthworms exhibit distinct biological traits contributing to ecosystem resilience.As a keystone species of terrestrial ecosystem,they influence soil health.This study investigates the transformation of bacterial population as they pass through the gut of Metaphire birmanica,with a focus on knowing its role in shaping microbial diversity,directing to understand its influence on soil fertility and ecosystem restoration.We used advance high-throughput 16S rRNA sequencing to assess surrounding soil,earthworm gut,and cast samples.Following DNA extraction,the process of amplification,and sequencing,bacterial taxonomy was compared across various levels using bioinformatics.Findings revealed that M.birmanica gut acted as a selective environment,leading a distinct microbial composition that predominantly favored anaerobic bacteria like Firmicutes.The observed microbial patterns suggest potential ecological implications,including possible roles of families like Sphingomonadaceae and Pseudomonadaceae in nutrient cycling and Bacillus and Pseudomonas in plant growth promotion,increased nutrient availability,and enhanced soil structure.These results highlight M.birmanica's significant role in influencing soil microbial ecology,offering significant implications for sustainable agriculture and soil restoration.展开更多
For the basic condition that the quality and efficiency of forestry cadres' education and training in China are not high at present, this paper first analyzes the necessity of constructing the management mechanism...For the basic condition that the quality and efficiency of forestry cadres' education and training in China are not high at present, this paper first analyzes the necessity of constructing the management mechanism for forestry cadres' education and training from two aspects: improve the quality of forestry cadres' education and training and the inherent needs of forestry development, and also summarizes the existing problems in the management of forestry cadres' education and training in China at present, and finally, this paper puts forward the corresponding solutions from four aspects: strengthen macro planning, strengthen the construction of the quality supervision mechanism, reform the incentive system and safeguard the mechanism.展开更多
Allelopathic effects of different doses of Eucalyptus camaldulensis leaf litters were investigated through an experiment in the green house of Institute of Forestry and Environmental Sciences, Chittagong, Bangladesh. ...Allelopathic effects of different doses of Eucalyptus camaldulensis leaf litters were investigated through an experiment in the green house of Institute of Forestry and Environmental Sciences, Chittagong, Bangladesh. Three popular agricultural crops： Falen （Vigna unguiculata）, Chickpea （Cicer arietinum）, Arhor （Cajanus cajan） and two widely used plantation trees： Sada koroi （Albizia procera） and Ipil ipil （Leucaena leucocephala） were selected as bioassay species. Experiment was set on tray at room temperature 27℃. The effects of different doses of leaf litter extracts were compared to the control. Results suggest that leaf litters of E, camaldulesis induced inhibitory effects, It was also found that the effect depend on concentration of extract and litterfall, type of receiver species. Higher concentration of the materials had the higher effect and vice versa. Though all the bioassay species were suppressed some of them showed better performance. Vigna unguiculata, Cicer arietinum are recommended in agroforestry based on this present Experiment output. In mixed plantation, Leucaena leucochephala is a better choice while compared to Albizia procera.展开更多
Because the oilfields in eastern China are in the very high water cut development stage, accurate forecast of oilfield development indices is important for exploiting the oilfields efficiently. Regarding the problems ...Because the oilfields in eastern China are in the very high water cut development stage, accurate forecast of oilfield development indices is important for exploiting the oilfields efficiently. Regarding the problems of the small number of samples collected for oilfield development indices, a new support vector regression prediction method for development indices is proposed in this paper. This method uses the principle of functional simulation to determine the input-output of a support vector machine prediction system based on historical oilfield development data. It chooses the kernel function of the support vector machine by analyzing time series characteristics of the development index; trains and tests the support vector machine network with historical data to construct the support vector regression prediction model of oilfield development indices; and predicts the development index. The case study shows that the proposed method is feasible, and predicted development indices agree well with the development performance of very high water cut oilfields.展开更多
Molasses wastewater was evaluated as substrate for biohydrogen production by anaerobic fermentation in a novel continuous mixed attached growth reactor ( CMAGR ) with aeration pretreated sludge attached onto granular ...Molasses wastewater was evaluated as substrate for biohydrogen production by anaerobic fermentation in a novel continuous mixed attached growth reactor ( CMAGR ) with aeration pretreated sludge attached onto granular activated carbon under continuous flow condition.It was indicated that the CMAGR system was operated at the conditions of influent COD of 2000～6000mg / L , hydraulic retention time ( HRT ) of 6hand temperature of 35 ℃ , when the pH value and oxidation-reduction potential ( ORP ) ranged from 4.16and-434 mV respectively , stable ethanol-type fermentation was formed with the sum of ethanol and acetate concentration ratio of 89.3%to the total liquid products after 40days operation.The H 2 content in biogas and chemical oxygen demand ( COD ) removal were estimated to be 46.6% and 13% , respectively.It was also investigated that the effects of organic loading rates ( OLRs ) on CMAGR hydrogen production system.It was found that hydrogen production yield increased from 3.72 mmol / hL to 12.51 mmol / hL as OLRs increased from 8 kg / m 3 d to 32 kg / m 3 d.The maximum hydrogen production rate of 12.51mmol / hL at a OLR of 32kg / m 3 d and the maximum hydrogen yield by substrate consumed was 130.57 mmol / mol happened at OLR of 16 kg / m 3 d.Greater pHs appeared to be favour to butyrate production and the maximum of 0.51mol / mol was obtained at pH of 4.14.However , ethanol / acetate ratio was greater than 1.1at pH fluctuated between 3.4 - 3.6and 4.1 - 4.4which indicated that these pHs were favour to ethanol type fermentation.Therefore , the continuous mixed attached growth reactor ( CMAGR ) could be a promising attached growth system for biohydrogen fermentation.展开更多
Field experiments to evaluate four different colored sticky cards for trapping non-target insects were conducted in an organic maize field in the Heinigou region of China. Yellow, blue, green, and red sticky cards wer...Field experiments to evaluate four different colored sticky cards for trapping non-target insects were conducted in an organic maize field in the Heinigou region of China. Yellow, blue, green, and red sticky cards were used to trap insects in the field. The total number of insects species caught was 54, with 3,862 individuals recorded. Over half of the specimens caught were non-target insects, including phytophagous insects, particularly dipteran species(including many mosquitoes)(50.3%), followed by target pests(37.0%), and beneficial insects(12.7%). Statistical analysis revealed a significant difference in attraction to target pests, non-target pests, and beneficial insects among treatment groups. The results showed that higher numbers of target pests(Myzus persicae Sulzer, Empoasca flavescens Fabricius, Nysius ericaecshinly Schilling) were caught on yellow sticky card traps compared with blue, green, or red sticky card traps, indicating that yellow was the best trap color for target pests, with green and blue being progressively less attractive. For non-target insects, including phytophagous insects, flies, and mosquitoes,higher numbers of were caught on blue sticky card traps compared with yellow,green, or red sticky card traps. Our study indicated that blue was the most attractive color for flies, especially for the housefly, Musca domestica Linnaeus. Our study also showed that most beneficial insects exhibited preferences to particular trap color characteristics: yellow was the most attractive color for parasitic wasps and lady beetles; blue was the most attractive color for hoverflies and honeybees. In contrast,green and red had no significant attraction to beneficial insects.展开更多
An experiment was conducted to assess the effect of leaf litter of Leucaena leucocephala on two forest crops Sada koroi （Albizia procera）, Ipil ipil （L. leucocephala） and three agricultural crops Falen （Vigna ung...An experiment was conducted to assess the effect of leaf litter of Leucaena leucocephala on two forest crops Sada koroi （Albizia procera）, Ipil ipil （L. leucocephala） and three agricultural crops Falen （Vigna unguiculata）, Chickpea （Citer arietinum） and Arhor （Cajanus cajan） in the nursery of the Institute of Forestry and Environmental Sciences, Chittagong University, Bangladesh, in a Randomized Block Design. Results suggested that leaf litters ofL. leucocephala induced inhibitory effects on germination and growth of bioassay. It was also found that the effect depended on concentration of extract and litterfall, type of receptor species. Higher concentration of the materials had the higher effect and vice versa. Growth response of receptor crops varied with the variation of leaf litter application. The study revealed that application of low-dose leaf litter specially litter of 10 g·m^-2 had stimulating effect on shoot growth of C. arietinum, Vunguiculata and A. procera. While in all other cases significant inhibitory effect was observed and it was significantly increased with the increase of leaf litter application. However, the trend of inhibition was uneven with treatments. Root growth was found to be more affected than shoot growth.展开更多
An experiment was conducted to observe the inhibitory effects of the leaf extracts derived from Albizia lebbeck （L.） Benth. On germination and growth behavior of some popular agricultural crops （receptor） of Bangl...An experiment was conducted to observe the inhibitory effects of the leaf extracts derived from Albizia lebbeck （L.） Benth. On germination and growth behavior of some popular agricultural crops （receptor） of Bangladesh. Experiments were set on sterilized petridishes with a photoperiod of 24 h at room temperature of 27-30℃. The effects of the different concentrations of aqueous extracts were compared to distil water （control.）. The aqueous extracts of leaf caused significant inhibitory effect on germination, root and shoot elongation and development of lateral roots of receptor plants. Bioassays indicated that the inhibitory effect was proportional to the concentrations of the extracts and higher concentration （50%-100%） had the stronger inhibitory effect whereas the lower concentration （10%-25%） showed stimulatory effect in some cases. The study also revealed that, inhibitory effect was much pronounced in root and lateral root development rather than germination and shoot growth.展开更多
The tea plant(Camellia sinensis L.)is an important commercial crop with remarkably high catechin concentrations.Tea is popular worldwide given the plant's health benefits.Catechins are the main astringent substanc...The tea plant(Camellia sinensis L.)is an important commercial crop with remarkably high catechin concentrations.Tea is popular worldwide given the plant's health benefits.Catechins are the main astringent substance in tea and are synthesized mainly via the phenylpropanoid pathway.In this study,eight cultivars of tea plants harvested both in spring and autumn were used to investigate differences in catechin concentrations by using high-performance liquid chromatography.The expression levels of genes associated with catechin biosynthesis were investigated using reverse transcription-quantitative polymerase chain reaction.The results indicated that the total catechin(TC)concentrations were significantly higher in tea plants harvested in autumn than in those harvested in spring,based on higher concentrations of epigallocatechin(EGC)in autumn tea(P<0.01).The expression of the genes phenylalanine ammonia-lyase(PAL),flavanone 3-hydroxylase(F3H),flavonoid 3′,5′-hydroxylase(F3′5′H),dihydroflavonol 4-reductase(DFR),and anthocyanidin synthase(ANS)is closely related to the TC content of tea plants in both spring and autumn.Positive correlations between PAL,cinnamate 4-hydroxylase(C4H),F3H,and DFR expression and EGC accumulation in autumn tea were identified,with correlation coefficients of 0.710,0.763,0.884,and 0.707,respectively.A negative correlation between ANS expression level and EGC concentrations in tea plants harvested in spring was noted(r=−0.732).Additionally,negative correlations between F3H and ANS expression levels and the catechin content were identified in spring tea,whereas the correlations were positive in autumn tea.Significant differences in the F3H and ANS expression levels between spring and autumn tea indicate that F3H and ANS are potentially key genes affecting catechin accumulation in tea plants.展开更多
Status of organic carbon (C), total nitrogen (N), available potassium (K), calcium (Ca) and phosphorus (P) in three different depths (0-5 cm, 5-15 cm and 15?30 cm) on two hill slopes of 35% and 55% in orange orchard c...Status of organic carbon (C), total nitrogen (N), available potassium (K), calcium (Ca) and phosphorus (P) in three different depths (0-5 cm, 5-15 cm and 15?30 cm) on two hill slopes of 35% and 55% in orange orchard cultivated by the Mro tribe of Chittagong Hill Tracts (CHTs) were evaluated and compared with those in degraded bush forests, through digging three profiles in each land use. The content of all the five nutrients was found to be higher in the soil of orange orchard than in the soil of forest. But the variation was not consistent for both the slopes. The content varied depth wise also, having the highest value in surface soil in case of both the land uses on both the slopes. A mean available K content was significantly higher in orange orchard than in forest on 55% slope, while it was lower on 35% slope. Surface soil contained the nutrients of K and Ca with the amount of 0.2905-mg·g^(-1) soil and 3.025-mg·g^(-1)soil respectively in the orchard, while 0.1934-mg·g^(-1) soil and 1.6083-mg·g^(-1) soil were respectively in the forest. Organic carbon and total nitrogen were found more or less similar in surface soil on both the land uses showing a slight difference. Available P was found only in orange orchard, and in forest it was too little in amount to detect by the spectrophotometer. The degraded forests were poor in nutrient content due to high rate of soil erosion, which would be possible to be improved by bringing it under tree cover as proved by the adaptation of orange orchard there.展开更多
A comprehensive evaluation system,which focused on optimal selection of raw material forest species for edible fungi,was established by combination of Analytic Hierarchy Process(AHP)and Experts Grading Method(EGM).The...A comprehensive evaluation system,which focused on optimal selection of raw material forest species for edible fungi,was established by combination of Analytic Hierarchy Process(AHP)and Experts Grading Method(EGM).The evaluation system had 4 indices of grade I and 12 indices of grade II.Among the 12 indices of grade II,the weighted values of production quality of edible fungi P2(0.2874),usable time P7(0.1873),annual average increment P8(0.1873),edible fungi production suitability P1(0.0958)were larger than the values of others.Based on the comprehensive evaluation system,this study analyzed and screened 47 broadleaf species of 40 genera of 25 families.There were 16 broadleaf species having the comprehensive evaluation scores of equal to or greater than2.4000,which were available as major tree species for edible fungi development of Guizhou Province,especially species such as Liriodendron chinense,Quercus acutissima,Alnus cremastogyne,Betula luminfera,Elaeocarpus duclouxii,Elaeocarpus sylvestris,Choerospondias axillaris.The 10 broadleaf tree species with comprehensive evaluation score of 2.1000≤Y 2.4000 were recommended as candidates for edible fungi production,while the 21 broadleaf species with the comprehensive evaluation score of less than 2.1000 were not recommended.展开更多
This study was designed to use LiDAR data to research tree heights in montane forest blocks of Kenya. It uses a completely randomised block design to asses if differences exist in forest heights: 1) among montane fore...This study was designed to use LiDAR data to research tree heights in montane forest blocks of Kenya. It uses a completely randomised block design to asses if differences exist in forest heights: 1) among montane forest blocks, 2) among Agro ecological zones (AEZ) within each forest block and 3) between similar AEZ in different forest blocks. Forest height data from the Geoscience Laser Altimeter System (GLAS) on the Ice Cloud and Land Elevation Satellite (ICE-SAT) for the period 2003-2009 was used for 2146 circular plots, of 0.2 - 0.25 ha in size. Results indicate that, tree height is largely influenced by Agro ecological conditions and the wetter zones have taller trees in the upper, middle and lower highlands. In the upper highland zones of limited human activity, tree heights did not vary among forest blocks. Variations in height among forest blocks and within forest blocks were exaggerated in regions of active human intervention.展开更多
According to the relationship between Toona sinensis Roem stand volume,productivity and forest age,site conditions,stand density and other factors,through selecting 8 representative cities or counties,using standard i...According to the relationship between Toona sinensis Roem stand volume,productivity and forest age,site conditions,stand density and other factors,through selecting 8 representative cities or counties,using standard investigation and stem analysis method,this paper makes relatively systematic research about the Toona sinensis Roem plantation accumulation,productivity,and the relationship between them and site conditions.Through comparative analysis indicators of multiple site conditions,this paper expects to give a more comprehensive picture about the source of accumulation and productivity difference.展开更多
Anaerobic process of biohydrogen production was developed. There is a great deal of Lactobacillus bacteria in the activated sludge of biohydrogen reactor. The isolation and identification of different anaerobic bacter...Anaerobic process of biohydrogen production was developed. There is a great deal of Lactobacillus bacteria in the activated sludge of biohydrogen reactor. The isolation and identification of different anaerobic bacteria in the reactor is important for fermented biohydrogen production process by anaerobic digesting organic wastewater. Considering with the physiological and biochemical traits,morphological characteristics and 16SrDNA sequence,the isolated Rennanqilyf13 is a new species in Lactobacillus genus. And the temporary nomenclature of the species is Lactobacillus Strain Rennanqilyf13 sp. nov.展开更多
A method based on PCR amplification of the 16S rRNA gene (rDNA)-23S rDNA intergenic spacer regions (ISR) was developed for the identification of species within the novel group hydrogen-producing anaerobes. The sizes o...A method based on PCR amplification of the 16S rRNA gene (rDNA)-23S rDNA intergenic spacer regions (ISR) was developed for the identification of species within the novel group hydrogen-producing anaerobes. The sizes of the PCR products varied from 1264 to 398 bp. Strain of isolate Rennanqilyf 3 was characterized as having products of 1262,398,638,437 and 436 bp. The isolate Rennanqilyf 1 had product of 1264 bp. The isolate Rennanqilyf 13 had products of 1261,579 and 485 bp. Of the 3 species of the novel group hydrogen-producing anaerobes examined, no one was indistinguishable. Two environmental isolates were identified as hydrogen-producing bacteria, which were new species in present taxon. Rennanqilyf 3 could not be associated with any Clostridium sp. studied. Rennanqilyf 1 could be classified into Clostridium genus. The combination between 16S rDNA equencing and length polymorphisms of IRS in 16S-23S rDNA is a better method for determining species of the hydrogen-producing bacteria.展开更多
A study was conducted to assess growth, carbon stock and sequestration potential of oil palm plantations along a chronosequence in Mizoram, Northeast India for which a total of 148 oil palms drawn from different age g...A study was conducted to assess growth, carbon stock and sequestration potential of oil palm plantations along a chronosequence in Mizoram, Northeast India for which a total of 148 oil palms drawn from different age group plantations (1 to 11 years) were sampled for their biometric parameters and assessment of carbon stock through partial non-destructive methods. All the growth parameters of oil palm (trunk height, crown depth, total height, trunk diameter) and biomass drew from different parts of the palm showed a significant (p belowground biomass (BGB) > standing litter biomass > deadwood biomass > understorey biomass. AGB, BGB and deadwood biomass followed an increasing trend while understorey biomass decreased with age. An 11-year oil palm plantation accumulated 111.96 Mg ha-1 biomass with a carbon density of 49.90 Mg C ha-1 and could sequester 3.70 Mg C ha-1 year-1 in 10 years after planting in Mizoram, Northeast India. The findings showed considerable carbon storage with comparative higher values in oil palm plantations than shifting cultivation fallows. This will enable policy and decision makers in framing climate change mitigation and adaptation policies regarding the extension of oil palm plantations in Mizoram.展开更多
Land use change activities have greatly affected the total ecosystem carbon stock (TECS) and also contribute to global change through emission of greenhouse gases. The present study assessed the change in vegetation b...Land use change activities have greatly affected the total ecosystem carbon stock (TECS) and also contribute to global change through emission of greenhouse gases. The present study assessed the change in vegetation biomass carbon stock (VBCS) and soil organic carbon stock (SOCS) following conversion in major land use sectors (agriculture, agroforestry, forest and plantation) in Mizoram, Northeast India. SOCS was the highest in agroforestry (50.85 Mg C ha-1) and the lowest in agriculture (33.99 Mg C ha-1). VBCS was the highest in plantation (131.66 Mg C ha-1) and the lowest in agriculture (7.44 Mg C ha-1). The highest positive TECS change rate was observed when agriculture was converted to plantation (6.61 Mg C ha-1·yr-1), while negative rate of change in carbon stock was observed following the establishment of agriculture from other land use. A positive rate of change was observed in both VBCS and SOCS with TECS rate of 3.58 Mg C ha-1·yr-1 when agriculture got converted to agroforestry. The absolute carbon stock change rates were higher in VBCS than SOCS signifying the importance to maintain tree based vegetation cover.展开更多
The topic of carbon sequestration in forest ecosystems has recently taken a lot of attention due to concerns about global climate change. As a spontaneous species of the Central Middle Atlas, the Atlas Cedar was the s...The topic of carbon sequestration in forest ecosystems has recently taken a lot of attention due to concerns about global climate change. As a spontaneous species of the Central Middle Atlas, the Atlas Cedar was the subject of our study. Thus, a total of 30 sample trees were subjected to the weight measurements for the estimation of biomass and organic carbon stock in a logging lot in the Azrou forest. The amount of sequestered carbon was then extrapolated in all stand forests studied from the developed carbomass models. The results obtained show that the largest allocation of carbon stock (93%) is in the stem, followed by branches (5%) and foliage (2%). The average carbon storage in this cedar forest is 99.42 tC/ha (aboveground and belowground), or 364.58 t/ha of CO2, a value significantly higher than that found in other Moroccan forest ecosystems.展开更多
A pot experiment has been conducted in Faculty of Agricultural and Forestry, Lath House of Horticultural Department, School of Plant Production, Duhok University during the growing season 2010-2011. The study consiste...A pot experiment has been conducted in Faculty of Agricultural and Forestry, Lath House of Horticultural Department, School of Plant Production, Duhok University during the growing season 2010-2011. The study consisted of testing the effects of four different growth media （Clay, Loam, Clay ＋ sheep manure （1：1） and Loam ＋ sheep manure （1：1） as volumetric rates on vegetative and flowering growth characters of five different cultivars of Hyacinths plant （Blue Giant, City of Haarlem, Jon Bos, Delf Blue and Fondante）. The experiment was laid out in randomized complete block design （RCBD） of two factors in three replicates. Media mostly affected the parameters studied during the experiment. Early emergence （22.53 days） and flowering （73.13 days） was recorded in medium consisting of loam and sheep manure, while maximum plant height （19.75 cm）, leaves number （6.13）, leaf area （31.47 cm2） were recorded in clay medium. Maximum number of florets plant-l （31.93） and spike length （7.95 cm） were recorded in medium consist of clay and sheep manure. Maximum length of spike stem （9.61 cm） and total chlorophyll percentage （53.45%） were recorded for loam medium. Among the cultivars, some parameters showed significant variation. Early emergence （20.42 days）, maximum plant height （20.35 cm）, leaf area per plant （33.01 cm2） and length of spike stem （15.10 cm） were given by cv. Fondante. Maximum number of florets plantl （35.58） and spike lengths （8.63 cm） were recorded by cv. Blue Giant. High percentage of total chlorophyll （58.15%） was recorded in cv. Jon Bos..展开更多
文摘Earthworms exhibit distinct biological traits contributing to ecosystem resilience.As a keystone species of terrestrial ecosystem,they influence soil health.This study investigates the transformation of bacterial population as they pass through the gut of Metaphire birmanica,with a focus on knowing its role in shaping microbial diversity,directing to understand its influence on soil fertility and ecosystem restoration.We used advance high-throughput 16S rRNA sequencing to assess surrounding soil,earthworm gut,and cast samples.Following DNA extraction,the process of amplification,and sequencing,bacterial taxonomy was compared across various levels using bioinformatics.Findings revealed that M.birmanica gut acted as a selective environment,leading a distinct microbial composition that predominantly favored anaerobic bacteria like Firmicutes.The observed microbial patterns suggest potential ecological implications,including possible roles of families like Sphingomonadaceae and Pseudomonadaceae in nutrient cycling and Bacillus and Pseudomonas in plant growth promotion,increased nutrient availability,and enhanced soil structure.These results highlight M.birmanica's significant role in influencing soil microbial ecology,offering significant implications for sustainable agriculture and soil restoration.
文摘For the basic condition that the quality and efficiency of forestry cadres' education and training in China are not high at present, this paper first analyzes the necessity of constructing the management mechanism for forestry cadres' education and training from two aspects: improve the quality of forestry cadres' education and training and the inherent needs of forestry development, and also summarizes the existing problems in the management of forestry cadres' education and training in China at present, and finally, this paper puts forward the corresponding solutions from four aspects: strengthen macro planning, strengthen the construction of the quality supervision mechanism, reform the incentive system and safeguard the mechanism.
基金Intercooperation,Agroforestry Improvement Project and Village and Farm Forestry Project (IC-VFFP, AFIP) Rajshahi (Funded by Swiss Agency for Development Cooperation,SDC)
文摘Allelopathic effects of different doses of Eucalyptus camaldulensis leaf litters were investigated through an experiment in the green house of Institute of Forestry and Environmental Sciences, Chittagong, Bangladesh. Three popular agricultural crops： Falen （Vigna unguiculata）, Chickpea （Cicer arietinum）, Arhor （Cajanus cajan） and two widely used plantation trees： Sada koroi （Albizia procera） and Ipil ipil （Leucaena leucocephala） were selected as bioassay species. Experiment was set on tray at room temperature 27℃. The effects of different doses of leaf litter extracts were compared to the control. Results suggest that leaf litters of E, camaldulesis induced inhibitory effects, It was also found that the effect depend on concentration of extract and litterfall, type of receiver species. Higher concentration of the materials had the higher effect and vice versa. Though all the bioassay species were suppressed some of them showed better performance. Vigna unguiculata, Cicer arietinum are recommended in agroforestry based on this present Experiment output. In mixed plantation, Leucaena leucochephala is a better choice while compared to Albizia procera.
基金support from Scientific Research Fund of Sichuan Provincial Education Department, P. R. China (No. 07za143)
文摘Because the oilfields in eastern China are in the very high water cut development stage, accurate forecast of oilfield development indices is important for exploiting the oilfields efficiently. Regarding the problems of the small number of samples collected for oilfield development indices, a new support vector regression prediction method for development indices is proposed in this paper. This method uses the principle of functional simulation to determine the input-output of a support vector machine prediction system based on historical oilfield development data. It chooses the kernel function of the support vector machine by analyzing time series characteristics of the development index; trains and tests the support vector machine network with historical data to construct the support vector regression prediction model of oilfield development indices; and predicts the development index. The case study shows that the proposed method is feasible, and predicted development indices agree well with the development performance of very high water cut oilfields.
基金support from the National Hi-Tech R&D Program(863 Program)Ministry of Science & Technology,China(2006AA05Z109)+2 种基金Shanghai Science and Technology Bureau(071605122)Shanghai Education Committee(07ZZ156)GRAP09,Northeast Forestry University are gratefully acknowledged
文摘Molasses wastewater was evaluated as substrate for biohydrogen production by anaerobic fermentation in a novel continuous mixed attached growth reactor ( CMAGR ) with aeration pretreated sludge attached onto granular activated carbon under continuous flow condition.It was indicated that the CMAGR system was operated at the conditions of influent COD of 2000～6000mg / L , hydraulic retention time ( HRT ) of 6hand temperature of 35 ℃ , when the pH value and oxidation-reduction potential ( ORP ) ranged from 4.16and-434 mV respectively , stable ethanol-type fermentation was formed with the sum of ethanol and acetate concentration ratio of 89.3%to the total liquid products after 40days operation.The H 2 content in biogas and chemical oxygen demand ( COD ) removal were estimated to be 46.6% and 13% , respectively.It was also investigated that the effects of organic loading rates ( OLRs ) on CMAGR hydrogen production system.It was found that hydrogen production yield increased from 3.72 mmol / hL to 12.51 mmol / hL as OLRs increased from 8 kg / m 3 d to 32 kg / m 3 d.The maximum hydrogen production rate of 12.51mmol / hL at a OLR of 32kg / m 3 d and the maximum hydrogen yield by substrate consumed was 130.57 mmol / mol happened at OLR of 16 kg / m 3 d.Greater pHs appeared to be favour to butyrate production and the maximum of 0.51mol / mol was obtained at pH of 4.14.However , ethanol / acetate ratio was greater than 1.1at pH fluctuated between 3.4 - 3.6and 4.1 - 4.4which indicated that these pHs were favour to ethanol type fermentation.Therefore , the continuous mixed attached growth reactor ( CMAGR ) could be a promising attached growth system for biohydrogen fermentation.
基金Supported by the Misereor Foundation(grant ref:335-031-1028 Z)
文摘Field experiments to evaluate four different colored sticky cards for trapping non-target insects were conducted in an organic maize field in the Heinigou region of China. Yellow, blue, green, and red sticky cards were used to trap insects in the field. The total number of insects species caught was 54, with 3,862 individuals recorded. Over half of the specimens caught were non-target insects, including phytophagous insects, particularly dipteran species(including many mosquitoes)(50.3%), followed by target pests(37.0%), and beneficial insects(12.7%). Statistical analysis revealed a significant difference in attraction to target pests, non-target pests, and beneficial insects among treatment groups. The results showed that higher numbers of target pests(Myzus persicae Sulzer, Empoasca flavescens Fabricius, Nysius ericaecshinly Schilling) were caught on yellow sticky card traps compared with blue, green, or red sticky card traps, indicating that yellow was the best trap color for target pests, with green and blue being progressively less attractive. For non-target insects, including phytophagous insects, flies, and mosquitoes,higher numbers of were caught on blue sticky card traps compared with yellow,green, or red sticky card traps. Our study indicated that blue was the most attractive color for flies, especially for the housefly, Musca domestica Linnaeus. Our study also showed that most beneficial insects exhibited preferences to particular trap color characteristics: yellow was the most attractive color for parasitic wasps and lady beetles; blue was the most attractive color for hoverflies and honeybees. In contrast,green and red had no significant attraction to beneficial insects.
文摘An experiment was conducted to assess the effect of leaf litter of Leucaena leucocephala on two forest crops Sada koroi （Albizia procera）, Ipil ipil （L. leucocephala） and three agricultural crops Falen （Vigna unguiculata）, Chickpea （Citer arietinum） and Arhor （Cajanus cajan） in the nursery of the Institute of Forestry and Environmental Sciences, Chittagong University, Bangladesh, in a Randomized Block Design. Results suggested that leaf litters ofL. leucocephala induced inhibitory effects on germination and growth of bioassay. It was also found that the effect depended on concentration of extract and litterfall, type of receptor species. Higher concentration of the materials had the higher effect and vice versa. Growth response of receptor crops varied with the variation of leaf litter application. The study revealed that application of low-dose leaf litter specially litter of 10 g·m^-2 had stimulating effect on shoot growth of C. arietinum, Vunguiculata and A. procera. While in all other cases significant inhibitory effect was observed and it was significantly increased with the increase of leaf litter application. However, the trend of inhibition was uneven with treatments. Root growth was found to be more affected than shoot growth.
文摘An experiment was conducted to observe the inhibitory effects of the leaf extracts derived from Albizia lebbeck （L.） Benth. On germination and growth behavior of some popular agricultural crops （receptor） of Bangladesh. Experiments were set on sterilized petridishes with a photoperiod of 24 h at room temperature of 27-30℃. The effects of the different concentrations of aqueous extracts were compared to distil water （control.）. The aqueous extracts of leaf caused significant inhibitory effect on germination, root and shoot elongation and development of lateral roots of receptor plants. Bioassays indicated that the inhibitory effect was proportional to the concentrations of the extracts and higher concentration （50%-100%） had the stronger inhibitory effect whereas the lower concentration （10%-25%） showed stimulatory effect in some cases. The study also revealed that, inhibitory effect was much pronounced in root and lateral root development rather than germination and shoot growth.
基金This research was financially supported by the National Program on Key Basic Research Projects(The 973 Program:2012CB113900)Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement.
文摘The tea plant(Camellia sinensis L.)is an important commercial crop with remarkably high catechin concentrations.Tea is popular worldwide given the plant's health benefits.Catechins are the main astringent substance in tea and are synthesized mainly via the phenylpropanoid pathway.In this study,eight cultivars of tea plants harvested both in spring and autumn were used to investigate differences in catechin concentrations by using high-performance liquid chromatography.The expression levels of genes associated with catechin biosynthesis were investigated using reverse transcription-quantitative polymerase chain reaction.The results indicated that the total catechin(TC)concentrations were significantly higher in tea plants harvested in autumn than in those harvested in spring,based on higher concentrations of epigallocatechin(EGC)in autumn tea(P<0.01).The expression of the genes phenylalanine ammonia-lyase(PAL),flavanone 3-hydroxylase(F3H),flavonoid 3′,5′-hydroxylase(F3′5′H),dihydroflavonol 4-reductase(DFR),and anthocyanidin synthase(ANS)is closely related to the TC content of tea plants in both spring and autumn.Positive correlations between PAL,cinnamate 4-hydroxylase(C4H),F3H,and DFR expression and EGC accumulation in autumn tea were identified,with correlation coefficients of 0.710,0.763,0.884,and 0.707,respectively.A negative correlation between ANS expression level and EGC concentrations in tea plants harvested in spring was noted(r=−0.732).Additionally,negative correlations between F3H and ANS expression levels and the catechin content were identified in spring tea,whereas the correlations were positive in autumn tea.Significant differences in the F3H and ANS expression levels between spring and autumn tea indicate that F3H and ANS are potentially key genes affecting catechin accumulation in tea plants.
文摘Status of organic carbon (C), total nitrogen (N), available potassium (K), calcium (Ca) and phosphorus (P) in three different depths (0-5 cm, 5-15 cm and 15?30 cm) on two hill slopes of 35% and 55% in orange orchard cultivated by the Mro tribe of Chittagong Hill Tracts (CHTs) were evaluated and compared with those in degraded bush forests, through digging three profiles in each land use. The content of all the five nutrients was found to be higher in the soil of orange orchard than in the soil of forest. But the variation was not consistent for both the slopes. The content varied depth wise also, having the highest value in surface soil in case of both the land uses on both the slopes. A mean available K content was significantly higher in orange orchard than in forest on 55% slope, while it was lower on 35% slope. Surface soil contained the nutrients of K and Ca with the amount of 0.2905-mg·g^(-1) soil and 3.025-mg·g^(-1)soil respectively in the orchard, while 0.1934-mg·g^(-1) soil and 1.6083-mg·g^(-1) soil were respectively in the forest. Organic carbon and total nitrogen were found more or less similar in surface soil on both the land uses showing a slight difference. Available P was found only in orange orchard, and in forest it was too little in amount to detect by the spectrophotometer. The degraded forests were poor in nutrient content due to high rate of soil erosion, which would be possible to be improved by bringing it under tree cover as proved by the adaptation of orange orchard there.
基金Supported by the Fund Project for Research Personnel in Forestry of the Department of Forestry of Guizhou Province(Qianlinkehe J[2012]No.04)
文摘A comprehensive evaluation system,which focused on optimal selection of raw material forest species for edible fungi,was established by combination of Analytic Hierarchy Process(AHP)and Experts Grading Method(EGM).The evaluation system had 4 indices of grade I and 12 indices of grade II.Among the 12 indices of grade II,the weighted values of production quality of edible fungi P2(0.2874),usable time P7(0.1873),annual average increment P8(0.1873),edible fungi production suitability P1(0.0958)were larger than the values of others.Based on the comprehensive evaluation system,this study analyzed and screened 47 broadleaf species of 40 genera of 25 families.There were 16 broadleaf species having the comprehensive evaluation scores of equal to or greater than2.4000,which were available as major tree species for edible fungi development of Guizhou Province,especially species such as Liriodendron chinense,Quercus acutissima,Alnus cremastogyne,Betula luminfera,Elaeocarpus duclouxii,Elaeocarpus sylvestris,Choerospondias axillaris.The 10 broadleaf tree species with comprehensive evaluation score of 2.1000≤Y 2.4000 were recommended as candidates for edible fungi production,while the 21 broadleaf species with the comprehensive evaluation score of less than 2.1000 were not recommended.
文摘This study was designed to use LiDAR data to research tree heights in montane forest blocks of Kenya. It uses a completely randomised block design to asses if differences exist in forest heights: 1) among montane forest blocks, 2) among Agro ecological zones (AEZ) within each forest block and 3) between similar AEZ in different forest blocks. Forest height data from the Geoscience Laser Altimeter System (GLAS) on the Ice Cloud and Land Elevation Satellite (ICE-SAT) for the period 2003-2009 was used for 2146 circular plots, of 0.2 - 0.25 ha in size. Results indicate that, tree height is largely influenced by Agro ecological conditions and the wetter zones have taller trees in the upper, middle and lower highlands. In the upper highland zones of limited human activity, tree heights did not vary among forest blocks. Variations in height among forest blocks and within forest blocks were exaggerated in regions of active human intervention.
文摘According to the relationship between Toona sinensis Roem stand volume,productivity and forest age,site conditions,stand density and other factors,through selecting 8 representative cities or counties,using standard investigation and stem analysis method,this paper makes relatively systematic research about the Toona sinensis Roem plantation accumulation,productivity,and the relationship between them and site conditions.Through comparative analysis indicators of multiple site conditions,this paper expects to give a more comprehensive picture about the source of accumulation and productivity difference.
基金Shanghai Education Committee Foundation (Grant No.N07ZZ156 S0701004 P1402).
文摘Anaerobic process of biohydrogen production was developed. There is a great deal of Lactobacillus bacteria in the activated sludge of biohydrogen reactor. The isolation and identification of different anaerobic bacteria in the reactor is important for fermented biohydrogen production process by anaerobic digesting organic wastewater. Considering with the physiological and biochemical traits,morphological characteristics and 16SrDNA sequence,the isolated Rennanqilyf13 is a new species in Lactobacillus genus. And the temporary nomenclature of the species is Lactobacillus Strain Rennanqilyf13 sp. nov.
基金Sponsored by Program of Shanghai Education Committee (Grant No07ZZ156)Key Subject Construction of Shanghai Education Committee(Grant NoP1402) the National Natural Science Fund of China(Grant No30470054)
文摘A method based on PCR amplification of the 16S rRNA gene (rDNA)-23S rDNA intergenic spacer regions (ISR) was developed for the identification of species within the novel group hydrogen-producing anaerobes. The sizes of the PCR products varied from 1264 to 398 bp. Strain of isolate Rennanqilyf 3 was characterized as having products of 1262,398,638,437 and 436 bp. The isolate Rennanqilyf 1 had product of 1264 bp. The isolate Rennanqilyf 13 had products of 1261,579 and 485 bp. Of the 3 species of the novel group hydrogen-producing anaerobes examined, no one was indistinguishable. Two environmental isolates were identified as hydrogen-producing bacteria, which were new species in present taxon. Rennanqilyf 3 could not be associated with any Clostridium sp. studied. Rennanqilyf 1 could be classified into Clostridium genus. The combination between 16S rDNA equencing and length polymorphisms of IRS in 16S-23S rDNA is a better method for determining species of the hydrogen-producing bacteria.
文摘A study was conducted to assess growth, carbon stock and sequestration potential of oil palm plantations along a chronosequence in Mizoram, Northeast India for which a total of 148 oil palms drawn from different age group plantations (1 to 11 years) were sampled for their biometric parameters and assessment of carbon stock through partial non-destructive methods. All the growth parameters of oil palm (trunk height, crown depth, total height, trunk diameter) and biomass drew from different parts of the palm showed a significant (p belowground biomass (BGB) > standing litter biomass > deadwood biomass > understorey biomass. AGB, BGB and deadwood biomass followed an increasing trend while understorey biomass decreased with age. An 11-year oil palm plantation accumulated 111.96 Mg ha-1 biomass with a carbon density of 49.90 Mg C ha-1 and could sequester 3.70 Mg C ha-1 year-1 in 10 years after planting in Mizoram, Northeast India. The findings showed considerable carbon storage with comparative higher values in oil palm plantations than shifting cultivation fallows. This will enable policy and decision makers in framing climate change mitigation and adaptation policies regarding the extension of oil palm plantations in Mizoram.
文摘Land use change activities have greatly affected the total ecosystem carbon stock (TECS) and also contribute to global change through emission of greenhouse gases. The present study assessed the change in vegetation biomass carbon stock (VBCS) and soil organic carbon stock (SOCS) following conversion in major land use sectors (agriculture, agroforestry, forest and plantation) in Mizoram, Northeast India. SOCS was the highest in agroforestry (50.85 Mg C ha-1) and the lowest in agriculture (33.99 Mg C ha-1). VBCS was the highest in plantation (131.66 Mg C ha-1) and the lowest in agriculture (7.44 Mg C ha-1). The highest positive TECS change rate was observed when agriculture was converted to plantation (6.61 Mg C ha-1·yr-1), while negative rate of change in carbon stock was observed following the establishment of agriculture from other land use. A positive rate of change was observed in both VBCS and SOCS with TECS rate of 3.58 Mg C ha-1·yr-1 when agriculture got converted to agroforestry. The absolute carbon stock change rates were higher in VBCS than SOCS signifying the importance to maintain tree based vegetation cover.
文摘The topic of carbon sequestration in forest ecosystems has recently taken a lot of attention due to concerns about global climate change. As a spontaneous species of the Central Middle Atlas, the Atlas Cedar was the subject of our study. Thus, a total of 30 sample trees were subjected to the weight measurements for the estimation of biomass and organic carbon stock in a logging lot in the Azrou forest. The amount of sequestered carbon was then extrapolated in all stand forests studied from the developed carbomass models. The results obtained show that the largest allocation of carbon stock (93%) is in the stem, followed by branches (5%) and foliage (2%). The average carbon storage in this cedar forest is 99.42 tC/ha (aboveground and belowground), or 364.58 t/ha of CO2, a value significantly higher than that found in other Moroccan forest ecosystems.
文摘A pot experiment has been conducted in Faculty of Agricultural and Forestry, Lath House of Horticultural Department, School of Plant Production, Duhok University during the growing season 2010-2011. The study consisted of testing the effects of four different growth media （Clay, Loam, Clay ＋ sheep manure （1：1） and Loam ＋ sheep manure （1：1） as volumetric rates on vegetative and flowering growth characters of five different cultivars of Hyacinths plant （Blue Giant, City of Haarlem, Jon Bos, Delf Blue and Fondante）. The experiment was laid out in randomized complete block design （RCBD） of two factors in three replicates. Media mostly affected the parameters studied during the experiment. Early emergence （22.53 days） and flowering （73.13 days） was recorded in medium consisting of loam and sheep manure, while maximum plant height （19.75 cm）, leaves number （6.13）, leaf area （31.47 cm2） were recorded in clay medium. Maximum number of florets plant-l （31.93） and spike length （7.95 cm） were recorded in medium consist of clay and sheep manure. Maximum length of spike stem （9.61 cm） and total chlorophyll percentage （53.45%） were recorded for loam medium. Among the cultivars, some parameters showed significant variation. Early emergence （20.42 days）, maximum plant height （20.35 cm）, leaf area per plant （33.01 cm2） and length of spike stem （15.10 cm） were given by cv. Fondante. Maximum number of florets plantl （35.58） and spike lengths （8.63 cm） were recorded by cv. Blue Giant. High percentage of total chlorophyll （58.15%） was recorded in cv. Jon Bos..
