Wood heat treatment has increased signifi- cantly in recent years and is still growing as an industrial process to improve some wood properties. We studied the change of swellingand surface roughness of common alder ...Wood heat treatment has increased signifi- cantly in recent years and is still growing as an industrial process to improve some wood properties. We studied the change of swellingand surface roughness of common alder （Alnus glutinosa （L.） Gaertn. ssp.glutinosa） and wych elm （Ulmus glabra Huds.） woods after heat treatment at two different temperatures and durations. The temperatures were 180 and 200 ℃ and the durations were 2 and 4 h. A stylus method was employed to evaluate the surface char- acteristics of the samples. Roughness measurements by the stylus method were made in the direction perpendicular to the fiber on the wood surface. Four main roughness parameters, mean arithmetic deviation of profile （Ra）, mean peak-to-valley height （Rz）, root mean square roughness （Rq）, and maximum roughness （Ry） were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Swelling and surface roughness parameters （Ra, Rz, Ry, and Rq） differed significantly for two temper- atures and two durations of heat treatment. Swelling and surface roughness values decreased with increasing treat- ment temperature and treatment times.展开更多
Four chiral 1,1?bis(oxazolinyl)ferrocenes(1a-1d) have been prepared and used as ligands in the copper catalyzed asymmetric cyclopropanation of styrene with ethyl diazoacetate (EDA) and the magnesium catalyzed Diels-Al...Four chiral 1,1?bis(oxazolinyl)ferrocenes(1a-1d) have been prepared and used as ligands in the copper catalyzed asymmetric cyclopropanation of styrene with ethyl diazoacetate (EDA) and the magnesium catalyzed Diels-Alder reaction between 3-acryloyl-2-oxazolidinone and cyclopentadiene. Enantioselectivities up to 24% and 41%, respectively, for cyclopropanation and Diels-Alder reaction were observed.展开更多
Up to now, the search for an efficient artificial diet to rear the predator Eriopis connexa, native to the Colombian highlands of Cundinamarca and Boyacá has been without success. Therefore, it is necessary to de...Up to now, the search for an efficient artificial diet to rear the predator Eriopis connexa, native to the Colombian highlands of Cundinamarca and Boyacá has been without success. Therefore, it is necessary to determine which of the available preys supply the best food for its development, survival and fertility. With this purpose, under controlled conditions, three aphid species, accessible within the natural habitat of the predator, were evaluated. The cabbage aphid (Brevicoryne brassicae) does not provide an adequate nutrition for the predator, and apparently, the glucosinolate content of this aphid is transferred and affecting the predator. Based on the demographic parameters such as net reproductive rate, finite reproduction rate, generational time and intrinsic growth rate, for three consecutive generations, it was determined that none of the other two aphid species can be considered either as optimum prey. Macrosiphum euphorbiae, as prey stands out over the alder aphid, Pterocallis sp., supplied as food. The influence that these three prey species had on the growth potential of the larval stages of the predator, under particular ambient conditions, is reported.展开更多
The investigation was conducted on the spatial and temporal distributions of soil organic mater （SOM） in the mixed plantations of alder （Aluns crernastogyne） and cypress （Cupressus funebris ） （MPAC）, which dis...The investigation was conducted on the spatial and temporal distributions of soil organic mater （SOM） in the mixed plantations of alder （Aluns crernastogyne） and cypress （Cupressus funebris ） （MPAC）, which distributed in the hilly areas of central Sichuan Basin （HACSB）. The results show that： （1） the spatial distribution of SOM among different sites at the same age are not significant before 15-year-old, but significant at 20-year-old, and not significant again after 25-year-old; （2） the SOM contents in 0-15 cm and 15-30 cm layers increase sharply from 10- to 15-year-old, and decline gradually from 15- to 30- year-old; the SOM contents of the 30-year-old PCP were 80. 38% and 78.42% higher than that of the 10-year-old, but 29.16% and 53.37% lower than that of 15-year-old in the 0-15 cm and 15-30 cm layers, respectively. The decrease of SOM contents would lead to the degradation of soil fertility and the decline of forest productivity.展开更多
A series of novel chiral C 2 symmetric bis(oxazoline) ligands have been synthesized. The copper and magnesium complexes, prepared in situ from copper(II) triflate or magnesium triflate with the new enantiop...A series of novel chiral C 2 symmetric bis(oxazoline) ligands have been synthesized. The copper and magnesium complexes, prepared in situ from copper(II) triflate or magnesium triflate with the new enantiopure oxazoline ligands, were evaluated as chiral catalysts in the enantioselective Diels Alder reaction of cyclopentadiene with N crotenoyl oxazolidin 2 one. Primary results showed that diastereoselectivity up to 94% and enantioselectivity up to 68% ee for endo products were observed respectively with these ligands.展开更多
This paper presents preliminary assessment of seedling survival and growth of green alder（Alnus viridis（Chaix） DC. in Lam. ＆ DC.） planted on fly ash disposal sites. This kind of post-industrial site is extremely ...This paper presents preliminary assessment of seedling survival and growth of green alder（Alnus viridis（Chaix） DC. in Lam. ＆ DC.） planted on fly ash disposal sites. This kind of post-industrial site is extremely hard to biologically stabilize without top-soiling. The experiment started with surface preparation using NPK start-up mineral fertilizer at 60–36–36 kg ha-1followed by initial stabilization through hydro-seeding with biosolids（sewage sludge 4 Mg ha-1dry mass） and a mixture of grasses（Dactylis glomerata L. and Lolium multiflorum Lam.）（200 kg ha-1）. Subsequently, three-years-old green alder seedlings were planted in plots on two substrate variants：the control（directly on combustion waste） and plots with3 dm3 lignite culm from a nearby mine introduced into the planting pit. Five years of preliminary monitoring show good survival seedling rates and growth parameters（height（h）, average increase in height（Dh）, number of shoots（L o）and leaf nitrogen supply in the fly ash disposal habitat.Treatment of the site with a combination of lignite culm in planting pits and preliminary surface preparation by hydroseeding and mineral fertilization had the most positive effect on green alder seedling parameters. The results indicate that it is possible and beneficial to use green alder for biological stabilization on fly ash disposal sites.展开更多
Three calculational models, statistical associating fluid theory (SAFT), modified SAFT, and Boublík Alder Chen Kreglewshi (BACK) are compared for supercritical CO 2 C 2H 5OH using a set of van der Waals ...Three calculational models, statistical associating fluid theory (SAFT), modified SAFT, and Boublík Alder Chen Kreglewshi (BACK) are compared for supercritical CO 2 C 2H 5OH using a set of van der Waals type mixing rules for both the BACK equation of state (EOS) and the SAFT EOS. Equations are presented for the residual Helmholtz free energy, residual chemical potentials, and compressibilty factor for mixtures. A comparison with experimental vapor liquid equilibrium (VLE) data reveals that the BACK EOS together with the suggested mixing rules provides more accurate prediction of the binary system than the SAFT or the modified SAFT model with no adjustable binary parameters. The correlation results are improved with an adjustable parameter. 展开更多
The statistical associating fluid theory (SAFT) Boublík Alder Chen Kreglewshi(BACK) equation of state is employed to correlate vapor liquid equilibria of 16 binary mixtures composed of supercritical fluid...The statistical associating fluid theory (SAFT) Boublík Alder Chen Kreglewshi(BACK) equation of state is employed to correlate vapor liquid equilibria of 16 binary mixtures composed of supercritical fluids with other fluids at elevated pressures. The van der Waals mixing rules are used and the binary parameters are adjusted to experimental data. The SAFT BACK equation of state provides a better correlation of vapor liquid equilibrium than the original BACK equation. Consequently, the binary parameters computed from the data sets can be used to accurately predict the saturated densities of the vapor and liquid phases. 展开更多
Himalayan alder species are proven to be very useful in traditional as well as contemporary agroforestry practice. These nitrogen-fixing trees are also useful in the land restoration. Therefore, understanding the dist...Himalayan alder species are proven to be very useful in traditional as well as contemporary agroforestry practice. These nitrogen-fixing trees are also useful in the land restoration. Therefore, understanding the distribution of Himalayan alder and the potential zone for plantation is meaningful in the agroforestry sector. Suitable climatic zones of Alnus spp. were modelled in Max Ent software using a subset of least correlated bioclimatic variables for current conditions(1950 -2000), topographic variables(DEM derived) and Landuse Landcover(LULC) data. We generated several models and selected the best model against random models using ANOVA and t-test. The environmental variables that best explained the current distribution of the species were identified and used to project into the future. For future projections, ensemble scenarios of climate change projection derived from the results of 19 Earth System Models(ESM) were used. Our model revealed that the most favorable conditions for Alnus nepalensis are in central Nepal in the moist north-west facing slope, whereas for Alnus nitida they are in western Nepal.The major climatic factor that contributes to Alnus species distribution in Nepal appears to be precipitation during the warmest quarter for A. nepalensis and precipitation during the driest quarter for A. nitida. Future projections revealed changes in the probability distribution of these species, as well as where they need conservation and where they can be planted. Also, our model predicts that the distribution of Alnus spp. in hilly regions will remain unchanged, and therefore may represent sites that can be used to revitalize traditional agroforestry systems and extract source material for land restoration.展开更多
Nature and its exploration is one of the most frequent objects of scientific research. Phenology can be described either as the study of natural events, or of biological events, in relation to climate. The Czech Hydro...Nature and its exploration is one of the most frequent objects of scientific research. Phenology can be described either as the study of natural events, or of biological events, in relation to climate. The Czech Hydrometeorological Institute operates phenological network （45 wild plants） with allergology important species within the observation program （the program includes among other species also the Common Hazel （Corylus avellana L.）, the Common Alder （Alnus glutinosa （L.） Gaert.）, the Silver Birch （Betula pendula Roth.）, the Meadow Foxtail （Alopecurus pratensis L.） and the Cocks Foot （Dactyl＆ glomerata L.））. We have statistically evaluated the phenological stages closely connected with the pollen grains release into the air （the beginning of flowering-BBCH 61 and the end of flowering-BBCH 69） including maps creation. The processed period was within last twenty years 1991-2010. The maps were processed using geographic information systems （Application Clidata-GIS, method Clidata-DEM）. The input data were used the mean dates of phenophase entrance from the twenty year period 1991-2010. The mean onset date of the beginning of flowering was between 24th February and the 24th March （the Common Hazel）, between 6th March and 2nd April （the Common Alder）, between 13th April and 7th May （the Silver Birch）, between 5thMay and 23rd May （the Meadow Foxtail） and between 16th May and 12th June （the Cocks Foot）. The mean onset date of the end of flowering was from 18th March till the 15th April （the Common Hazel）, from 27th March till 19th April （the Common Alder）, from 28th April till 21st May （the Silver Birch）, from 25th May till 6th June （the Meadow Foxtail） and from 7th May till 23rd June （the Cocks Foot）. The duration of flowering lasts on average with selected allergens as follows： 22-23 days with standard deviation 2.3-5.3 days （the Common Hazel）, 14-15 days with standard deviation 2.1-2.7 days （the Common Alder）, 17-21 days w展开更多
Background: Natural afforestation of former agricultural lands with alder species is common in Europe. Symbiotic nitrogen fixation by actinomycetes associated with alder species has been widely used for improvement of...Background: Natural afforestation of former agricultural lands with alder species is common in Europe. Symbiotic nitrogen fixation by actinomycetes associated with alder species has been widely used for improvement of soil properties of abandoned agricultural lands, but relatively little is known of the interactions of these processes with soil type and chemical composition. We conducted a space-for time study with soil sampling under and outside grey alder tree canopies on two different soil groups to explore effects of colonisation of former agricultural lands by alder on soil properties.Results: The results were analysed using analysis of variance. During the first 25 years after afforestation of former agricultural lands there was a significant increase in content of Ctot, Ntot, K+, Fe3+, Mn2+and available P in the topsoil(0–10 cm and 11–20 cm) of Dystric Arenosols soils, which are deficient in organic matter. Such trends were not evident in organic matter rich Endostagnic Umbrisols soils, in which exchangeable K+concentration decreased and exchangeable Fe3+and Al3+concentration increased.Conclusions: The results show that the effects of grey alder on soil chemical properties depend on initial soil properties. The invasion of agricultural land by grey alder leads to spatial variability of soil chemical properties creating a mosaic pattern.展开更多
Macroscopic fungi on Caucasian alder wood(Alnus subcordata)were identified and tested as a source of betulin and betulinic acid(the most important metabolites of the Betulaceae family)to evaluate levels of phenols,fla...Macroscopic fungi on Caucasian alder wood(Alnus subcordata)were identified and tested as a source of betulin and betulinic acid(the most important metabolites of the Betulaceae family)to evaluate levels of phenols,flavonoids and antioxidant activity.Ganoderma applanatum,Lenzites betulina,Trichaptum biforme,Rigidoporus ulamrius,Fomes fomentarius,Schizophyllum commune,Auricularia mesenterica,and Trametes versicolor were among those identified,and they differed significantly in the level of betulin and betulinic acid and phenols,flavonoids and antioxidant properties in fungal tissues extracted with methanol and with ethanol(p≤0.01).G.applanatum had the most betulin(3.642%)and S.commune the most betulinic acid(1.413%).All tested fungi had high antioxidant activity,and L.betulina had the highest(97.775%).The highest amounts of phenol(719.993 mg mL-1)and flavonoids(361.403 mg mL-1)were found in the ethanolic extract from G.applanatum.Considering the results of this study and the low cost and convenient access to these fungi,they should be good sources for producing different drugs.展开更多
Background:Black alder(Alnus glutinosa)forests are in severe decline across their area of distribution due to a disease caused by the soil-borne pathogenic Phytophthora alni species complex(class Oomycetes),“alder Ph...Background:Black alder(Alnus glutinosa)forests are in severe decline across their area of distribution due to a disease caused by the soil-borne pathogenic Phytophthora alni species complex(class Oomycetes),“alder Phytopththora”.Mapping of the different types of damages caused by the disease is challenging in high density ecosystems in which spectral variability is high due to canopy heterogeneity.Data obtained by unmanned aerial vehicles(UAVs)may be particularly useful for such tasks due to the high resolution,flexibility of acquisition and cost efficiency of this type of data.In this study,A.glutinosa decline was assessed by considering four categories of tree health status in the field:asymptomatic,dead and defoliation above and below a 50% threshold.A combination of multispectral Parrot Sequoia and UAV unmanned aerial vehicles-red green blue(RGB)data were analysed using classical random forest(RF)and a simple and robust three-step logistic modelling approaches to identify the most important forest health indicators while adhering to the principle of parsimony.A total of 34 remote sensing variables were considered,including a set of vegetation indices,texture features from the normalized difference vegetation index(NDVI)and a digital surface model(DSM),topographic and digital aerial photogrammetry-derived structural data from the DSM at crown level.Results:The four categories identified by the RF yielded an overall accuracy of 67%,while aggregation of the legend to three classes(asymptomatic,defoliated,dead)and to two classes(alive,dead)improved the overall accuracy to 72% and 91% respectively.On the other hand,the confusion matrix,computed from the three logistic models by using the leave-out cross-validation method yielded overall accuracies of 75%,80% and 94% for four-,three-and two-level classifications,respectively.Discussion:The study findings provide forest managers with an alternative robust classification method for the rapid,effective assessment of areas affected and non-affected by the disease,t展开更多
文摘Wood heat treatment has increased signifi- cantly in recent years and is still growing as an industrial process to improve some wood properties. We studied the change of swellingand surface roughness of common alder （Alnus glutinosa （L.） Gaertn. ssp.glutinosa） and wych elm （Ulmus glabra Huds.） woods after heat treatment at two different temperatures and durations. The temperatures were 180 and 200 ℃ and the durations were 2 and 4 h. A stylus method was employed to evaluate the surface char- acteristics of the samples. Roughness measurements by the stylus method were made in the direction perpendicular to the fiber on the wood surface. Four main roughness parameters, mean arithmetic deviation of profile （Ra）, mean peak-to-valley height （Rz）, root mean square roughness （Rq）, and maximum roughness （Ry） were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Swelling and surface roughness parameters （Ra, Rz, Ry, and Rq） differed significantly for two temper- atures and two durations of heat treatment. Swelling and surface roughness values decreased with increasing treat- ment temperature and treatment times.
文摘Four chiral 1,1?bis(oxazolinyl)ferrocenes(1a-1d) have been prepared and used as ligands in the copper catalyzed asymmetric cyclopropanation of styrene with ethyl diazoacetate (EDA) and the magnesium catalyzed Diels-Alder reaction between 3-acryloyl-2-oxazolidinone and cyclopentadiene. Enantioselectivities up to 24% and 41%, respectively, for cyclopropanation and Diels-Alder reaction were observed.
文摘Up to now, the search for an efficient artificial diet to rear the predator Eriopis connexa, native to the Colombian highlands of Cundinamarca and Boyacá has been without success. Therefore, it is necessary to determine which of the available preys supply the best food for its development, survival and fertility. With this purpose, under controlled conditions, three aphid species, accessible within the natural habitat of the predator, were evaluated. The cabbage aphid (Brevicoryne brassicae) does not provide an adequate nutrition for the predator, and apparently, the glucosinolate content of this aphid is transferred and affecting the predator. Based on the demographic parameters such as net reproductive rate, finite reproduction rate, generational time and intrinsic growth rate, for three consecutive generations, it was determined that none of the other two aphid species can be considered either as optimum prey. Macrosiphum euphorbiae, as prey stands out over the alder aphid, Pterocallis sp., supplied as food. The influence that these three prey species had on the growth potential of the larval stages of the predator, under particular ambient conditions, is reported.
文摘The investigation was conducted on the spatial and temporal distributions of soil organic mater （SOM） in the mixed plantations of alder （Aluns crernastogyne） and cypress （Cupressus funebris ） （MPAC）, which distributed in the hilly areas of central Sichuan Basin （HACSB）. The results show that： （1） the spatial distribution of SOM among different sites at the same age are not significant before 15-year-old, but significant at 20-year-old, and not significant again after 25-year-old; （2） the SOM contents in 0-15 cm and 15-30 cm layers increase sharply from 10- to 15-year-old, and decline gradually from 15- to 30- year-old; the SOM contents of the 30-year-old PCP were 80. 38% and 78.42% higher than that of the 10-year-old, but 29.16% and 53.37% lower than that of 15-year-old in the 0-15 cm and 15-30 cm layers, respectively. The decrease of SOM contents would lead to the degradation of soil fertility and the decline of forest productivity.
文摘A series of novel chiral C 2 symmetric bis(oxazoline) ligands have been synthesized. The copper and magnesium complexes, prepared in situ from copper(II) triflate or magnesium triflate with the new enantiopure oxazoline ligands, were evaluated as chiral catalysts in the enantioselective Diels Alder reaction of cyclopentadiene with N crotenoyl oxazolidin 2 one. Primary results showed that diastereoselectivity up to 94% and enantioselectivity up to 68% ee for endo products were observed respectively with these ligands.
基金financially supported by the Polish Ministry of Science and Higher Education in frame of DS 3420 KEk L2013,Department of Forest Ecology,Agricultural University of Krakow
文摘This paper presents preliminary assessment of seedling survival and growth of green alder（Alnus viridis（Chaix） DC. in Lam. ＆ DC.） planted on fly ash disposal sites. This kind of post-industrial site is extremely hard to biologically stabilize without top-soiling. The experiment started with surface preparation using NPK start-up mineral fertilizer at 60–36–36 kg ha-1followed by initial stabilization through hydro-seeding with biosolids（sewage sludge 4 Mg ha-1dry mass） and a mixture of grasses（Dactylis glomerata L. and Lolium multiflorum Lam.）（200 kg ha-1）. Subsequently, three-years-old green alder seedlings were planted in plots on two substrate variants：the control（directly on combustion waste） and plots with3 dm3 lignite culm from a nearby mine introduced into the planting pit. Five years of preliminary monitoring show good survival seedling rates and growth parameters（height（h）, average increase in height（Dh）, number of shoots（L o）and leaf nitrogen supply in the fly ash disposal habitat.Treatment of the site with a combination of lignite culm in planting pits and preliminary surface preparation by hydroseeding and mineral fertilization had the most positive effect on green alder seedling parameters. The results indicate that it is possible and beneficial to use green alder for biological stabilization on fly ash disposal sites.
文摘Three calculational models, statistical associating fluid theory (SAFT), modified SAFT, and Boublík Alder Chen Kreglewshi (BACK) are compared for supercritical CO 2 C 2H 5OH using a set of van der Waals type mixing rules for both the BACK equation of state (EOS) and the SAFT EOS. Equations are presented for the residual Helmholtz free energy, residual chemical potentials, and compressibilty factor for mixtures. A comparison with experimental vapor liquid equilibrium (VLE) data reveals that the BACK EOS together with the suggested mixing rules provides more accurate prediction of the binary system than the SAFT or the modified SAFT model with no adjustable binary parameters. The correlation results are improved with an adjustable parameter.
文摘The statistical associating fluid theory (SAFT) Boublík Alder Chen Kreglewshi(BACK) equation of state is employed to correlate vapor liquid equilibria of 16 binary mixtures composed of supercritical fluids with other fluids at elevated pressures. The van der Waals mixing rules are used and the binary parameters are adjusted to experimental data. The SAFT BACK equation of state provides a better correlation of vapor liquid equilibrium than the original BACK equation. Consequently, the binary parameters computed from the data sets can be used to accurately predict the saturated densities of the vapor and liquid phases.
基金RBGE Edinburg databasethe National Herbarium and Plant Laboratories(KATH),Godawari+5 种基金Tribhuvan University Central Herbarium(TUCH),Kirtipur,KathmanduNepal for facilitating with herbarium studyMs.Banu Ojaentire Cornell Nepal Study Programme family for partial financial supportCGIAR research programs on‘Forests,Trees and Agroforestry’(CRP6.2)programCenter for Mountain Ecosystem Studies to be a part of research on species distribution in Asian Highlands
文摘Himalayan alder species are proven to be very useful in traditional as well as contemporary agroforestry practice. These nitrogen-fixing trees are also useful in the land restoration. Therefore, understanding the distribution of Himalayan alder and the potential zone for plantation is meaningful in the agroforestry sector. Suitable climatic zones of Alnus spp. were modelled in Max Ent software using a subset of least correlated bioclimatic variables for current conditions(1950 -2000), topographic variables(DEM derived) and Landuse Landcover(LULC) data. We generated several models and selected the best model against random models using ANOVA and t-test. The environmental variables that best explained the current distribution of the species were identified and used to project into the future. For future projections, ensemble scenarios of climate change projection derived from the results of 19 Earth System Models(ESM) were used. Our model revealed that the most favorable conditions for Alnus nepalensis are in central Nepal in the moist north-west facing slope, whereas for Alnus nitida they are in western Nepal.The major climatic factor that contributes to Alnus species distribution in Nepal appears to be precipitation during the warmest quarter for A. nepalensis and precipitation during the driest quarter for A. nitida. Future projections revealed changes in the probability distribution of these species, as well as where they need conservation and where they can be planted. Also, our model predicts that the distribution of Alnus spp. in hilly regions will remain unchanged, and therefore may represent sites that can be used to revitalize traditional agroforestry systems and extract source material for land restoration.
文摘Nature and its exploration is one of the most frequent objects of scientific research. Phenology can be described either as the study of natural events, or of biological events, in relation to climate. The Czech Hydrometeorological Institute operates phenological network （45 wild plants） with allergology important species within the observation program （the program includes among other species also the Common Hazel （Corylus avellana L.）, the Common Alder （Alnus glutinosa （L.） Gaert.）, the Silver Birch （Betula pendula Roth.）, the Meadow Foxtail （Alopecurus pratensis L.） and the Cocks Foot （Dactyl＆ glomerata L.））. We have statistically evaluated the phenological stages closely connected with the pollen grains release into the air （the beginning of flowering-BBCH 61 and the end of flowering-BBCH 69） including maps creation. The processed period was within last twenty years 1991-2010. The maps were processed using geographic information systems （Application Clidata-GIS, method Clidata-DEM）. The input data were used the mean dates of phenophase entrance from the twenty year period 1991-2010. The mean onset date of the beginning of flowering was between 24th February and the 24th March （the Common Hazel）, between 6th March and 2nd April （the Common Alder）, between 13th April and 7th May （the Silver Birch）, between 5thMay and 23rd May （the Meadow Foxtail） and between 16th May and 12th June （the Cocks Foot）. The mean onset date of the end of flowering was from 18th March till the 15th April （the Common Hazel）, from 27th March till 19th April （the Common Alder）, from 28th April till 21st May （the Silver Birch）, from 25th May till 6th June （the Meadow Foxtail） and from 7th May till 23rd June （the Cocks Foot）. The duration of flowering lasts on average with selected allergens as follows： 22-23 days with standard deviation 2.3-5.3 days （the Common Hazel）, 14-15 days with standard deviation 2.1-2.7 days （the Common Alder）, 17-21 days w
基金supported by University of Latvia grant Nr. AAp2016/B041//Zd2016/AZ03 within the project “Climate change and sustainable use of natural resources”。
文摘Background: Natural afforestation of former agricultural lands with alder species is common in Europe. Symbiotic nitrogen fixation by actinomycetes associated with alder species has been widely used for improvement of soil properties of abandoned agricultural lands, but relatively little is known of the interactions of these processes with soil type and chemical composition. We conducted a space-for time study with soil sampling under and outside grey alder tree canopies on two different soil groups to explore effects of colonisation of former agricultural lands by alder on soil properties.Results: The results were analysed using analysis of variance. During the first 25 years after afforestation of former agricultural lands there was a significant increase in content of Ctot, Ntot, K+, Fe3+, Mn2+and available P in the topsoil(0–10 cm and 11–20 cm) of Dystric Arenosols soils, which are deficient in organic matter. Such trends were not evident in organic matter rich Endostagnic Umbrisols soils, in which exchangeable K+concentration decreased and exchangeable Fe3+and Al3+concentration increased.Conclusions: The results show that the effects of grey alder on soil chemical properties depend on initial soil properties. The invasion of agricultural land by grey alder leads to spatial variability of soil chemical properties creating a mosaic pattern.
基金The work was supported by Gorgan university of agricultural sciences and natural resources-grant no.93-323-28.
文摘Macroscopic fungi on Caucasian alder wood(Alnus subcordata)were identified and tested as a source of betulin and betulinic acid(the most important metabolites of the Betulaceae family)to evaluate levels of phenols,flavonoids and antioxidant activity.Ganoderma applanatum,Lenzites betulina,Trichaptum biforme,Rigidoporus ulamrius,Fomes fomentarius,Schizophyllum commune,Auricularia mesenterica,and Trametes versicolor were among those identified,and they differed significantly in the level of betulin and betulinic acid and phenols,flavonoids and antioxidant properties in fungal tissues extracted with methanol and with ethanol(p≤0.01).G.applanatum had the most betulin(3.642%)and S.commune the most betulinic acid(1.413%).All tested fungi had high antioxidant activity,and L.betulina had the highest(97.775%).The highest amounts of phenol(719.993 mg mL-1)and flavonoids(361.403 mg mL-1)were found in the ethanolic extract from G.applanatum.Considering the results of this study and the low cost and convenient access to these fungi,they should be good sources for producing different drugs.
基金co-funded by the European Commission LIFE program-Project LIFE FLUVIAL,LIFE16 NAT/ES/000771supported by the Portuguese Foundation for Science and Technology(FCT)through FCT the Investigador FCT Programme(IF/00059/2015)+2 种基金through the CEEC Individual Programme(2020.03356.CEECIND)CEF was supported through the FCT UIDB/00239/2020supported by the‘National Programme for the Promotion of Talent and Its Employability’of the Ministry of Economy,Industry,and Competitiveness(Torres-Quevedo program)through a postdoctoral grant(PTQ2018-010043).
文摘Background:Black alder(Alnus glutinosa)forests are in severe decline across their area of distribution due to a disease caused by the soil-borne pathogenic Phytophthora alni species complex(class Oomycetes),“alder Phytopththora”.Mapping of the different types of damages caused by the disease is challenging in high density ecosystems in which spectral variability is high due to canopy heterogeneity.Data obtained by unmanned aerial vehicles(UAVs)may be particularly useful for such tasks due to the high resolution,flexibility of acquisition and cost efficiency of this type of data.In this study,A.glutinosa decline was assessed by considering four categories of tree health status in the field:asymptomatic,dead and defoliation above and below a 50% threshold.A combination of multispectral Parrot Sequoia and UAV unmanned aerial vehicles-red green blue(RGB)data were analysed using classical random forest(RF)and a simple and robust three-step logistic modelling approaches to identify the most important forest health indicators while adhering to the principle of parsimony.A total of 34 remote sensing variables were considered,including a set of vegetation indices,texture features from the normalized difference vegetation index(NDVI)and a digital surface model(DSM),topographic and digital aerial photogrammetry-derived structural data from the DSM at crown level.Results:The four categories identified by the RF yielded an overall accuracy of 67%,while aggregation of the legend to three classes(asymptomatic,defoliated,dead)and to two classes(alive,dead)improved the overall accuracy to 72% and 91% respectively.On the other hand,the confusion matrix,computed from the three logistic models by using the leave-out cross-validation method yielded overall accuracies of 75%,80% and 94% for four-,three-and two-level classifications,respectively.Discussion:The study findings provide forest managers with an alternative robust classification method for the rapid,effective assessment of areas affected and non-affected by the disease,t
