Forests play a vital role in mitigating climate change through their physiological functions and metabolic processes,including their ability to convert solar energy into biomolecules.However,further research is necess...Forests play a vital role in mitigating climate change through their physiological functions and metabolic processes,including their ability to convert solar energy into biomolecules.However,further research is necessary to elucidate how structural characteristics of a forest and topographic settings influence energy conversion and surface temperature of a forest.In this study,we investigated a beech forest in central Germany using airborne laser scanning(ALS)point cloud data and land surface temperature(LST)data derived from Landsat 9 satellite imagery.We constructed 30 m×30 m plots across the study area(approximately 17 km2)to align the spatial resolution of the satellite imagery with the ALS data.We analyzed topographic variables(surface elevation,aspect and slope),forest attributes(canopy cover,canopy height,and woody area index),as well as forest structural complexity,quantified by the box-dimension(Db).Our analysis revealed that LST is significantly influenced by both forest attributes and topographic variables.A multiple linear regression model demonstrated an inverse relationship(R^(2)=0.38,AIC=8105)between LST and a combination of Db,elevation,slope,and aspect.However,the model residuals exhibited significant spatial dependency,as indicated by Moran’s I test.To address this,we applied a spatial autoregressive model,which effectively accounted for spatial autocorrelation and improved the model fit(AIC=746).Our findings indicate that elevation exerts the most substantial influence on LST,followed by forest structural complexity,slope,and aspect.We conclude that forest management practices that enhance structural complexity can effectively reduce land surface temperatures in forested landscapes.展开更多
Information on the most influential factors determining gas flux from soils is needed in predictive models for greenhouse gases emissions. We conducted an intensive soil and air sampling along a 2 000 m transect exten...Information on the most influential factors determining gas flux from soils is needed in predictive models for greenhouse gases emissions. We conducted an intensive soil and air sampling along a 2 000 m transect extending from a forest, pasture, grassland and corn field in Shizunai, Hokkaido （Japan）, measured CO2, CH4, N20 and NO fluxes and calculated soil bulk density （Pb）, air-filled porosity （fa） and total porosity （Ф）. Using diffusivity models based on either fa alone or on a combination of fa and 4, we predicted two pore space indices： the relative gas diffusion coefficient （Ds/Do） and the pore tortuosity factor （T）. The relationships between pore space indices （Ds/Do and T） and C02, CH4, N2O and NO fluxes were also studied. Results showed that the grassland had the highest Pb while fa and Ф were the highest in the forest. CO2, CH4, N20 and NO fluxes were the highest in the grassland while N20 dominated in the corn field. Few correlations existed between fa, Ф, Pb and gases fluxes while all models predicted that Ds/Do and T significantly correlated with CO2 and CH4 with correlation coefficient （r） ranging from 0.20 to 0.80. Overall, diffusivity models based on fa alone gave higher Ds/Do, lower τ, and higher R2 and better explained the relationship between pore space indices （Ds/Do and τ） and gases fluxes. Inclusion of Ds/Do and τ in predictive models will improve our understanding of the dynamics of greenhouse gas fluxes from soils. Ds/Do and τ can be easily obtained by measurements of soil air and water and existing diffusivity models.展开更多
In Central Europe, a large portion of post-mining sites were afforested with Scots pine, which is characterized by good adaptability and a tolerance for poor habitat at the beginning of forest ecosystem development. C...In Central Europe, a large portion of post-mining sites were afforested with Scots pine, which is characterized by good adaptability and a tolerance for poor habitat at the beginning of forest ecosystem development. Conversion of monoculture on mine sites into more biodi- verse mixed hardwood forests, especially on more fertile deposits, can be an emerging need in this part of Europe in next decades. The ability to classify the forests at these post-mining sites will facilitate proper species selection as well as the management and formation of the developed ecosystem＇s stability. This work describes the guidelines that can be followed to assess reclaimed mine soil （RMS） quality, using the mine soil quality index （MSQI） and a classification of developed forest sites as a basis of tree-stand species selection and conversion of pine monocul- tures. The research was conducted on four post-mining facilities （lignite, hard coal, sulphur, and sand pit mining areas） on different RMS sub- strates dominant in Central Europe. Soil quality assessment takes into account the following features of the soil： texture soil nutrients （Ca, Mg, K, Na, P）; acidity （pH KC1）; and Corg-to-Nt ratio in the initial organic horizon. An analysis was conducted of classification systems using the MSQI validation correlation （at p =0.05） with vegetation features af- fected by succession： aboveground biomass of forest floor and ecological indicators of vascular plants （calculated on the basis of EUenberg＇s （2009） system）. Eventually, in the analysed data set, the MSQI ranged from 0.270 for soils on quaternary sands to 0.720 for a mix of quaternary loamy sands with neogene clays. Potential forest habitat types and the role of the pine in the next generation of tree stands on different RMS parent rock substrate were proposed.展开更多
As a Nature-Based Solution,urban forests deliver a number of environmental ecosystem services(EESs).To quantify these EESs,well-defined,reliable,quantifiable and stable indicators are needed.With literature analysis a...As a Nature-Based Solution,urban forests deliver a number of environmental ecosystem services(EESs).To quantify these EESs,well-defined,reliable,quantifiable and stable indicators are needed.With literature analysis and expert knowledge gathered within COST Action FP1204 GreenInUrbs,we proposed a classification of urban forest EESs into three categories:(A)regulation of air,water,soil and climate;(B)provisioning of habitat quality;and(C)provisioning of other goods and services.Each category is divided into EES types:(a)amelioration of air quality;restoration of soil and water;amelioration of the microclimate;removal of CO2 from the air;(b)provision of habitat for biodiversity;support for resilient urban ecosystems;provision of genetic diversity;and(c)provision of energy and nutrients;provision of grey infrastructure resilience.Each EES type provides one or more benefits.For each of these 12 benefits,we propose a set of indicators to be used when analyzing the impacts on the identified EESs.Around half of the 36 indicators are relevant to more than one single benefit,which highlights complex interrelationships.The indicators of wider applicability are tree and stand characteristics,followed by leaf physical traits and tree species composition.This knowledge is needed for the optimization of the EESs delivered by urban forests,now and in the future.展开更多
Relatively simple forest planting process in real life is not so simple. Its relationships with various environmental, climatic, ecological and other environmental conditions cause a lot of problems. In this paper, ha...Relatively simple forest planting process in real life is not so simple. Its relationships with various environmental, climatic, ecological and other environmental conditions cause a lot of problems. In this paper, hazard analysis critical control point （HACCP） analysis was conducted to identify the critical control points in forest regeneration process. As a result, it has a positive effect on the entire reforestation result. Critical control points will enable timely to draw attention to possible errors or incorrect solutions and consequently improve afforestation or restoration quality. Reforestation often occurs mistakes that lead to an unsuccessful reforestation. To remedy this situation, these critical control points should be identified with HAACP analysis.展开更多
The impacts of mechanised forest harvesting to soil physical properties are the major concern by forest managers, which have the potential to impact soil sustainability and forest productivity. Malaysia is practicing ...The impacts of mechanised forest harvesting to soil physical properties are the major concern by forest managers, which have the potential to impact soil sustainability and forest productivity. Malaysia is practicing reduce impact logging （RIL） and applying code of forest harvest practice in forest harvesting and operations for sustainable forest resources management. In 2001, a machinery called Rimbaka Timber Harvester R2020-A was introduced for timber extraction for peat swamp forest and later on the machine was introduced to the hill tropical forest as an alternative to other machines. The study aimed to evaluate soil compaction （soil cone index, soil bulk density, soil moisture content and soil pore space） by Rimbaka Timber Harvester R2020-A and crawler tractor KOMATSU D60-A. A total of five samples were randomly taken using core sampler of 50 mm height and 50 mm diameter at the beneath a lug imprint for passes 1, 4 and 8. Altogether samples were 45. The locations of sample were to the fight and left of each rut centre for both machines. Treatment effects were evaluated using analysis of variance （ANOVA）. Result showed that compaction by Rimbaka machine was increased bulk density from 1.14 to 1.43 g/cc, cone index from 1.94 to 3.45 g/cm3 decreased total pore space by 43% and decreased soil moisture content by 19%. Meanwhile compaction by KOMATSU D60-A was increased bulk density from 1.2 to 1.43 g/co, cone index from 1.24 to 1.94 g/cm3 decreased soil moisture content by 11% and total pore space by 6%, respectively. The value increased rapidly as more passes increase on the track surface. The higher soil disturbance by Rimbaka machine was due to physical design and specification of the machine. This study also observed that there was significant difference in the total passes of machinery used in harvesting operation. Although Rimbaka machine is showing more effected to soil compaction, the machine is a practical alternative to avoid skid trail and reduce road density in forest area.展开更多
The main objectives of this study were to detecting the land use and land cover change (LULC), using remote sensing techniques, then identify the reasons for rangeland and tree cover degradation in El Rawashda Forest,...The main objectives of this study were to detecting the land use and land cover change (LULC), using remote sensing techniques, then identify the reasons for rangeland and tree cover degradation in El Rawashda Forest, Gadarif State, Sudan. The study has conducted field experiment developed on an area of 20 feddans that was affected by deterioration in the forest and to assess the best method for rehabilitation of the vegetation cover in the area of study. The experimental area was divided into 5 blocks;each block consisted of 4 treatments: grass seeds and Talih (Acacia seyal var. seyal);sowing seeds just before autumn, sowing seeds after disc ploughing, sowing seeds using water harvesting technique and control (no seeding). In the present study an attempt has been made to analyze and monitor the LULC changes using multi‐temporal Landsat data deterioration in the forest and to assess the best method for restoration of the vegetation. In the present study, an attempt has been made to analyze and monitor the LULC changes using multi‐temporal Landsat data for years 1984, 1994 and 2013. LULC grades in the classification scheme are: Trees, Mechanized Rain-fed Agriculture (MRA), Grasses and Bare land. Individual classifications based on maximum likelihood of algorithm were used and the results showed a significant that extensive change of LULC patterns has occurred in all decades in the study area. The results also show Trees class was decreased, while MRA, Grasses and Bare land were increased. The seeding of the forage and Talih seeds after disc plowing gave the best results compared to the other treatments, followed by forage and Talih seed sowing under the water harvesting technique and broadcasting of forage and Talih seeds and finally the control.展开更多
In Central Europe,anthropogenic coniferous monocultures have been subject to conversion to more diverse mixed forests since the 1990s,however,they are still abundant across many forest landscapes.Artificial and natura...In Central Europe,anthropogenic coniferous monocultures have been subject to conversion to more diverse mixed forests since the 1990s,however,they are still abundant across many forest landscapes.Artificial and natural tree regeneration both play a key role during conversion by determining the species composition and structure of the future forests.Many abiotic and biotic factors can potentially influence the regeneration process and its specific combinations or interactions may be different among tree species and its developmental stages.Here,we aimed to identify and quantify the effect of the most important drivers on the density of the most abundant regenerating tree species(i.e.,Norway spruce and European beech),as well as on species and structural diversity of the tree regeneration.We studied tree regeneration in four former monospecific coniferous stand types(i.e.,Norway spruce,Scots pine,European larch,and Douglas fir)in Southwest Germany that have been under conversion to mixed forests since the 1990s.We sampled tree regeneration in four growth height classes together with a variety of potentially influencing factors on 108 sampling plots and applied multivariate analyses.We identified light availability in the understorey,stand structural attributes,browsing pressure,and diaspore source abundance as the most important factors for the density and diversity of tree regeneration.Particularly,we revealed speciesspecific differences in drivers of regeneration density.While spruce profited from increasing light availability and decreasing stand basal area,beech benefited either from a minor reduction or more strikingly from an increase in overstorey density.Increasing diaspore source abundance positively and a high browsing pressure negatively affected both species equally.Our results suggest that humus and topsoil properties were modified during conversion,probably due to changes in tree species composition and silvicultural activities.The species and structural diversity of the tree regeneration benefitted from increasing light availability,decreasing stand basal area,and a low to moderate browsing pressure.We conclude that forest managers may carefully equilibrate among the regulation of overstorey cover,stand basal area,and browsing pressure to fulfil the objectives of forest conversion,i.e.,establishing and safeguarding a diverse tree regeneration to promote the development of mature mixed forests in the future.展开更多
Sorghum breeding significantly relies on the understanding of genetic diversity dynamics. Despite its importance, research on the geographical distribution of essential agro-morphological and phenological traits for a...Sorghum breeding significantly relies on the understanding of genetic diversity dynamics. Despite its importance, research on the geographical distribution of essential agro-morphological and phenological traits for achieving targeted breeding outcomes has been limited. This paper presents an analysis of five key traits—stem flavor, days to 50% maturity, plant height, grain color, and grain size—across 483 germplasm samples from 71 villages in Niger, based on data collected during a 2003 survey. The primary aim is to map the geographical distribution of these traits. The findings, illustrated on a map of Niger, provide insights into the regional distribution of these characteristics, aiding breeders and agronomists in understanding trait combinations for developing new sorghum varieties.展开更多
Fluctuations of greenhouse gases emissions and soil properties occur at short spatial and temporal scales, however, results are often reported for larger scales studies. We monitored CO2, CH4, and N2O fluxes and soil ...Fluctuations of greenhouse gases emissions and soil properties occur at short spatial and temporal scales, however, results are often reported for larger scales studies. We monitored CO2, CH4, and N2O fluxes and soil temperature （T）, thermal conductivity （K）, resistivity （R） and thermal diffusivity （D） from 2004 to 2006 in a pasture. Soil air samples for determination of CO2, CH4 and N2O concentrations were collected from static and vented chambers and analyzed within two hours of collection with a gas chromatograph. T, K, R and D were measured in-situ using a KD2 probe. Soil samples were also taken for measurements of soil chemical and physical properties. The pasture acted as a sink in 2004, a source in 2005 and again a sink of CH4 in 2006. CO2 and CH4 were highest, but N2O as well as T, K and D were lowest in 2004. Only K was correlated with C02 in 2004 while T correlated with both N2O （r = 0.76, p = 0.0001） and CO2 （r = 0.88, p = 0.0001） in 2005. In 2006, all gases fluxes were significantly correlated with T, K and R when the data for the entire year were considered. However, an in-depth examination of the data revealed the existence of month-to-month shifts, lack of correlation and differing spatial structures. These results stress the need for further studies on the relationship between soil properties and gases fluxes. K and R offer a promise as potential controlling factors for greenhouse gases fluxes in this pasture.展开更多
Wastewater treatment is a problem with much acuity in the city of Maradi in general, and particularly in the Communal District I of Maradi. It is for this reason that the present study was conducted which deals with w...Wastewater treatment is a problem with much acuity in the city of Maradi in general, and particularly in the Communal District I of Maradi. It is for this reason that the present study was conducted which deals with wastewater sanitation. The main objective of this study conducted through a survey is to investigate in the domestic wastewater sanitation in the Communal District I of Maradi city. Specifically, the study aims to estimate the amount of wastewater produced by households and to analyze the sanitation system at household and at district levels. The wastewater management practices in this district were assessed through a descriptive cross sectional study in which a total of 129 households were selected by sample distribution technique in the district neighborhoods and studied using interviewer and administered questionnaires at communal and household levels. The results of the study showed that the amount of domestic wastewater generated is quite large, about 32.27 m3 per person per day, and this comes from several sources including showers, laundry, dishwashing and income generating activities. The results also revealed that the unhealthy state of the Communal District I of Maradi is related to the absence of a wastewater treatment system, the methods and practices used in its management, and the population is also largely responsible for this unhealthy state and not willing to participate to a sanitation project.展开更多
The analysis of environmental impact effects on forest ecosystems has a theoretical and practical nature. Many methods have been developed to determine characteristics and intensity of this impact. Methodologically, t...The analysis of environmental impact effects on forest ecosystems has a theoretical and practical nature. Many methods have been developed to determine characteristics and intensity of this impact. Methodologically, they can be divided into three groups： environmental parameter, bioindicative and combined methods. To evaluate the environmental impact a combined method was used in this study, it was based on trees as the bioindicators and their response reactions, and environmental parameter analysis. In this study the bioindicator was Norway spruce （Picea abies （L.） Karst.）, whose response reaction was used to explain total impact volumes of environmental factors in different places in the region of Kurzeme and try to interpret the causes of these differences. As the bioindicators criterion was used response reaction of Norway spruce during a period of 20 years, which was expressed with cumulative and annual additional volume increment, and was depending on the location of the stand and its morphometric characteristics. The empirical material was collected in Kurzeme region in 28 sample plots that are located on two transects and in one reference stand. For the evaluation the widths of the last 40 year growth rings were measured. To express the environmental impact in Kurzeme region a multiple regression model was developed, which explains the environmental impact in the volume of 68.2%, the rest part can be explained by the local conditions of each stand. It must be noted that methodology used in this study is very sensitive, thus, each of the nuances in the dynamics of volume＇s annual reduced additional increments has biological and ecological cause.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
On the Equator, the Talihya North watershed is a vast area of nearly 581.7 km<sup>2</sup> that extends from the Cool Highlands on the Congo-Nile Crest in Lubero Territory to the Rift Valley in the Virunga ...On the Equator, the Talihya North watershed is a vast area of nearly 581.7 km<sup>2</sup> that extends from the Cool Highlands on the Congo-Nile Crest in Lubero Territory to the Rift Valley in the Virunga National Park in Beni Territory. This vast territory has an agropastoral vocation. Indeed, agricultural activities combined with the high population density in this watershed generate modifications in the landscape structure. The objective of this paper is to study the dynamics of land use from 1987 to 2020. To achieve this, two Landsat TM+ and ETM+ images and one Sentinel-2 image were analyzed. After the classification of the images based on the Maximum Likelihood algorithm, this study shows that two processes are evident in the landscape of the North Talihya watershed: deforestation and savannization. Forests that occupied 253.11 km<sup>2</sup> in 1987 have decreased to 201.12 km<sup>2</sup> in 2001 and to 123.04 km<sup>2</sup> in 2020. These area balances indicate that the natural forest formations in the North Talihya watershed have been converted primarily to croplands and fallows. The estimated annual deforestation rate between 1987 and 2020 is 2.18%. With this high rate of deforestation, mechanisms to restore degraded forest ecosystems in this watershed will need to be put in place. The sustainable management of residual forest ecosystems that have escaped human pressure is necessary for the conservation of biodiversity for future generations.展开更多
Water and its importance cannot be understated.Its greatest value lies in its ability and capacity to provide biological and environmental services.Water quality is an essential parameter to be studied when the overal...Water and its importance cannot be understated.Its greatest value lies in its ability and capacity to provide biological and environmental services.Water quality is an essential parameter to be studied when the overall focus is sustainable development keeping mankind at a focal point.The study assessed the water quality and its suitability for drinking purposes in most areas of Padada Watershed.In this study,nine identified sampling points were analyzed for different physico-chemical parameters such as turbidity,BOD(Biological Oxygen Demand),TSS(Total Solid Suspended),fecal coliform,pH,temperature,DO(Dissolved Oxygen),and SC(Specific Conductivity).Results found turbidity range from 0.74-19.7 NTU;BOD range from 0.04-2.2 mg/L;TSS range from 1-411 mg/L;fecal coliform range from<1.8-160,000 MPN/100mL.The temperature value ranges from 24.8-31.9°C;pH value ranges from 7.05-7.92;SC ranges from 119.7-551μS/cm while DO range from 4.87-8.14 mg/L.Moreover,the results revealed that most sampling sites exceeded the permissible limits.The highest concentration of fecal coliform indicates contamination which may cause possible human health infection.Thus,the water of Padada River Watershed is not potable for drinking and it is recommended to take beneficial steps to prevent adverse health effects to the community.展开更多
The Urban Commune of Maradi in Niger experienced increasingly frequent flooding following rainy episodes generating volumes and water flows that are difficult to control in recent years. This study aims to determine t...The Urban Commune of Maradi in Niger experienced increasingly frequent flooding following rainy episodes generating volumes and water flows that are difficult to control in recent years. This study aims to determine the impacts of runoff water in Commune II of Maradi City and to assess the role of urban planning in runoff management, as well as the strengths and weaknesses of urban sanitation in Maradi. The methodological approach used consisted of: 1) an interpretation of documentary data, 2) gathering information on runoff at several sites in the study area, and 3) interviews and questionnaires with local communities. This approach made it possible to understand the degree of vulnerability of the populations to flooding and then to propose sustainable solutions to reduce the vulnerability of the affected populations, through the implementation of effective urban rainwater management practices (USWMP). The results show that the impacts of runoff are mainly related to the lack of adequate storm water drainage networks in the area, but also to the nature of the habitats. Geomorphological factors such as the nature of the soil, the slope of the terrain and the altitude increase the degree of risk. In addition, the inadequacy and dilapidation of the drainage systems of the canals and above all the anarchic occupation of the land linked to accelerated urbanization are the cause of flooding by stagnation of rainwater. A phenomenon now linked to numerous deteriorations of urban equipment, the runoff of rainwater in the city of Maradi carries so many pollutants that municipalities, businesses and individuals should put in place pollution prevention measures.展开更多
Millet and maize play an important role in food and nutrition security in Ni-ger.Despite their importance both in terms of food and economics,these ce-real crops continue to face insect pests including the Fall armywo...Millet and maize play an important role in food and nutrition security in Ni-ger.Despite their importance both in terms of food and economics,these ce-real crops continue to face insect pests including the Fall armyworm,S.frugi-perda(Smith.,1797).This caterpillar appeared for the first time in 2016 in sub-Saharan Africa(Nigeria,Sao Tome,Benin and Togo)and the same year in Torodi in Niger.The Fall armyworm is present in all regions of Niger from where it attacks the main cereals.The damage caused by this pest poses a sig-nificant threat to the productivity of these crops.The objective of this study is to assess the incidence and severity of Fall armyworm damage on maize and millet in the Maradi region.The study was conducted at the station(INRAN)and in Djirataoua.Four(4)fields were chosen,population dynamics monitor-ing through Delta Traps for captures of adult males ofS.frugiperdaand larval scouting in the field.The“N”sampling technique was used to determine the natural S.frugiperdainfestation rate on corn(71.7%on maize produce in INRAN and 31.5%on maize produce in Djirataoua)and millet(17.4%on mil-let produce in Djirataoua and 7.8%on millet produce in INRAN).And the level of leaf damage recorded only scores 2 and 3 on millet and maize recorded up to score 7,measured using a method of the Davisetal.,(1992)Leaf Damage Assessment Scale/Score.These results will contribute to the development of an integrated management program for Fall armyworm.The main objective is to assess the impact of the fall armyworm,Spodopterafrugiperda(J.E.Smith),on maize and millet crops in the Maradi region.More specifically,the aim is to:1)Monitor fall armyworm population dynamics in the fields;2)De-termine the infestation rate ofS.frugiperdaon maize and millet;3)Assess the level of CLA leaf damage also on maize and millet.展开更多
文摘Forests play a vital role in mitigating climate change through their physiological functions and metabolic processes,including their ability to convert solar energy into biomolecules.However,further research is necessary to elucidate how structural characteristics of a forest and topographic settings influence energy conversion and surface temperature of a forest.In this study,we investigated a beech forest in central Germany using airborne laser scanning(ALS)point cloud data and land surface temperature(LST)data derived from Landsat 9 satellite imagery.We constructed 30 m×30 m plots across the study area(approximately 17 km2)to align the spatial resolution of the satellite imagery with the ALS data.We analyzed topographic variables(surface elevation,aspect and slope),forest attributes(canopy cover,canopy height,and woody area index),as well as forest structural complexity,quantified by the box-dimension(Db).Our analysis revealed that LST is significantly influenced by both forest attributes and topographic variables.A multiple linear regression model demonstrated an inverse relationship(R^(2)=0.38,AIC=8105)between LST and a combination of Db,elevation,slope,and aspect.However,the model residuals exhibited significant spatial dependency,as indicated by Moran’s I test.To address this,we applied a spatial autoregressive model,which effectively accounted for spatial autocorrelation and improved the model fit(AIC=746).Our findings indicate that elevation exerts the most substantial influence on LST,followed by forest structural complexity,slope,and aspect.We conclude that forest management practices that enhance structural complexity can effectively reduce land surface temperatures in forested landscapes.
基金Supported by the Japanese Society for the Promotion of Science (JSPS)the Ministry of Education of Japan (No. PI0701)
文摘Information on the most influential factors determining gas flux from soils is needed in predictive models for greenhouse gases emissions. We conducted an intensive soil and air sampling along a 2 000 m transect extending from a forest, pasture, grassland and corn field in Shizunai, Hokkaido （Japan）, measured CO2, CH4, N20 and NO fluxes and calculated soil bulk density （Pb）, air-filled porosity （fa） and total porosity （Ф）. Using diffusivity models based on either fa alone or on a combination of fa and 4, we predicted two pore space indices： the relative gas diffusion coefficient （Ds/Do） and the pore tortuosity factor （T）. The relationships between pore space indices （Ds/Do and T） and C02, CH4, N2O and NO fluxes were also studied. Results showed that the grassland had the highest Pb while fa and Ф were the highest in the forest. CO2, CH4, N20 and NO fluxes were the highest in the grassland while N20 dominated in the corn field. Few correlations existed between fa, Ф, Pb and gases fluxes while all models predicted that Ds/Do and T significantly correlated with CO2 and CH4 with correlation coefficient （r） ranging from 0.20 to 0.80. Overall, diffusivity models based on fa alone gave higher Ds/Do, lower τ, and higher R2 and better explained the relationship between pore space indices （Ds/Do and τ） and gases fluxes. Inclusion of Ds/Do and τ in predictive models will improve our understanding of the dynamics of greenhouse gas fluxes from soils. Ds/Do and τ can be easily obtained by measurements of soil air and water and existing diffusivity models.
基金financially supported by the Polish Ministry of Science and Higher Education Grant N 309 013 32/2076partly by statutory financial support of the Ministry of Science and Higher Education RP(DS-3420 in 2012 and 2013,Department of Forest Ecology University of Agriculture in Krakow
文摘In Central Europe, a large portion of post-mining sites were afforested with Scots pine, which is characterized by good adaptability and a tolerance for poor habitat at the beginning of forest ecosystem development. Conversion of monoculture on mine sites into more biodi- verse mixed hardwood forests, especially on more fertile deposits, can be an emerging need in this part of Europe in next decades. The ability to classify the forests at these post-mining sites will facilitate proper species selection as well as the management and formation of the developed ecosystem＇s stability. This work describes the guidelines that can be followed to assess reclaimed mine soil （RMS） quality, using the mine soil quality index （MSQI） and a classification of developed forest sites as a basis of tree-stand species selection and conversion of pine monocul- tures. The research was conducted on four post-mining facilities （lignite, hard coal, sulphur, and sand pit mining areas） on different RMS sub- strates dominant in Central Europe. Soil quality assessment takes into account the following features of the soil： texture soil nutrients （Ca, Mg, K, Na, P）; acidity （pH KC1）; and Corg-to-Nt ratio in the initial organic horizon. An analysis was conducted of classification systems using the MSQI validation correlation （at p =0.05） with vegetation features af- fected by succession： aboveground biomass of forest floor and ecological indicators of vascular plants （calculated on the basis of EUenberg＇s （2009） system）. Eventually, in the analysed data set, the MSQI ranged from 0.270 for soils on quaternary sands to 0.720 for a mix of quaternary loamy sands with neogene clays. Potential forest habitat types and the role of the pine in the next generation of tree stands on different RMS parent rock substrate were proposed.
基金financially supported by COST Action FP1204 GreenInUrbsPRIN project EUFORICCMinistry of Education and Science of the Russian Federation(the Agreement No.02.A03.21.0008)
文摘As a Nature-Based Solution,urban forests deliver a number of environmental ecosystem services(EESs).To quantify these EESs,well-defined,reliable,quantifiable and stable indicators are needed.With literature analysis and expert knowledge gathered within COST Action FP1204 GreenInUrbs,we proposed a classification of urban forest EESs into three categories:(A)regulation of air,water,soil and climate;(B)provisioning of habitat quality;and(C)provisioning of other goods and services.Each category is divided into EES types:(a)amelioration of air quality;restoration of soil and water;amelioration of the microclimate;removal of CO2 from the air;(b)provision of habitat for biodiversity;support for resilient urban ecosystems;provision of genetic diversity;and(c)provision of energy and nutrients;provision of grey infrastructure resilience.Each EES type provides one or more benefits.For each of these 12 benefits,we propose a set of indicators to be used when analyzing the impacts on the identified EESs.Around half of the 36 indicators are relevant to more than one single benefit,which highlights complex interrelationships.The indicators of wider applicability are tree and stand characteristics,followed by leaf physical traits and tree species composition.This knowledge is needed for the optimization of the EESs delivered by urban forests,now and in the future.
文摘Relatively simple forest planting process in real life is not so simple. Its relationships with various environmental, climatic, ecological and other environmental conditions cause a lot of problems. In this paper, hazard analysis critical control point （HACCP） analysis was conducted to identify the critical control points in forest regeneration process. As a result, it has a positive effect on the entire reforestation result. Critical control points will enable timely to draw attention to possible errors or incorrect solutions and consequently improve afforestation or restoration quality. Reforestation often occurs mistakes that lead to an unsuccessful reforestation. To remedy this situation, these critical control points should be identified with HAACP analysis.
文摘The impacts of mechanised forest harvesting to soil physical properties are the major concern by forest managers, which have the potential to impact soil sustainability and forest productivity. Malaysia is practicing reduce impact logging （RIL） and applying code of forest harvest practice in forest harvesting and operations for sustainable forest resources management. In 2001, a machinery called Rimbaka Timber Harvester R2020-A was introduced for timber extraction for peat swamp forest and later on the machine was introduced to the hill tropical forest as an alternative to other machines. The study aimed to evaluate soil compaction （soil cone index, soil bulk density, soil moisture content and soil pore space） by Rimbaka Timber Harvester R2020-A and crawler tractor KOMATSU D60-A. A total of five samples were randomly taken using core sampler of 50 mm height and 50 mm diameter at the beneath a lug imprint for passes 1, 4 and 8. Altogether samples were 45. The locations of sample were to the fight and left of each rut centre for both machines. Treatment effects were evaluated using analysis of variance （ANOVA）. Result showed that compaction by Rimbaka machine was increased bulk density from 1.14 to 1.43 g/cc, cone index from 1.94 to 3.45 g/cm3 decreased total pore space by 43% and decreased soil moisture content by 19%. Meanwhile compaction by KOMATSU D60-A was increased bulk density from 1.2 to 1.43 g/co, cone index from 1.24 to 1.94 g/cm3 decreased soil moisture content by 11% and total pore space by 6%, respectively. The value increased rapidly as more passes increase on the track surface. The higher soil disturbance by Rimbaka machine was due to physical design and specification of the machine. This study also observed that there was significant difference in the total passes of machinery used in harvesting operation. Although Rimbaka machine is showing more effected to soil compaction, the machine is a practical alternative to avoid skid trail and reduce road density in forest area.
文摘The main objectives of this study were to detecting the land use and land cover change (LULC), using remote sensing techniques, then identify the reasons for rangeland and tree cover degradation in El Rawashda Forest, Gadarif State, Sudan. The study has conducted field experiment developed on an area of 20 feddans that was affected by deterioration in the forest and to assess the best method for rehabilitation of the vegetation cover in the area of study. The experimental area was divided into 5 blocks;each block consisted of 4 treatments: grass seeds and Talih (Acacia seyal var. seyal);sowing seeds just before autumn, sowing seeds after disc ploughing, sowing seeds using water harvesting technique and control (no seeding). In the present study an attempt has been made to analyze and monitor the LULC changes using multi‐temporal Landsat data deterioration in the forest and to assess the best method for restoration of the vegetation. In the present study, an attempt has been made to analyze and monitor the LULC changes using multi‐temporal Landsat data for years 1984, 1994 and 2013. LULC grades in the classification scheme are: Trees, Mechanized Rain-fed Agriculture (MRA), Grasses and Bare land. Individual classifications based on maximum likelihood of algorithm were used and the results showed a significant that extensive change of LULC patterns has occurred in all decades in the study area. The results also show Trees class was decreased, while MRA, Grasses and Bare land were increased. The seeding of the forage and Talih seeds after disc plowing gave the best results compared to the other treatments, followed by forage and Talih seed sowing under the water harvesting technique and broadcasting of forage and Talih seeds and finally the control.
基金funded by the Bavarian Ministry for Food,Agriculture and Forestry (Grant No.F053)support by the Open Access Publication Funds/transformative agreements of the Gottingen University
文摘In Central Europe,anthropogenic coniferous monocultures have been subject to conversion to more diverse mixed forests since the 1990s,however,they are still abundant across many forest landscapes.Artificial and natural tree regeneration both play a key role during conversion by determining the species composition and structure of the future forests.Many abiotic and biotic factors can potentially influence the regeneration process and its specific combinations or interactions may be different among tree species and its developmental stages.Here,we aimed to identify and quantify the effect of the most important drivers on the density of the most abundant regenerating tree species(i.e.,Norway spruce and European beech),as well as on species and structural diversity of the tree regeneration.We studied tree regeneration in four former monospecific coniferous stand types(i.e.,Norway spruce,Scots pine,European larch,and Douglas fir)in Southwest Germany that have been under conversion to mixed forests since the 1990s.We sampled tree regeneration in four growth height classes together with a variety of potentially influencing factors on 108 sampling plots and applied multivariate analyses.We identified light availability in the understorey,stand structural attributes,browsing pressure,and diaspore source abundance as the most important factors for the density and diversity of tree regeneration.Particularly,we revealed speciesspecific differences in drivers of regeneration density.While spruce profited from increasing light availability and decreasing stand basal area,beech benefited either from a minor reduction or more strikingly from an increase in overstorey density.Increasing diaspore source abundance positively and a high browsing pressure negatively affected both species equally.Our results suggest that humus and topsoil properties were modified during conversion,probably due to changes in tree species composition and silvicultural activities.The species and structural diversity of the tree regeneration benefitted from increasing light availability,decreasing stand basal area,and a low to moderate browsing pressure.We conclude that forest managers may carefully equilibrate among the regulation of overstorey cover,stand basal area,and browsing pressure to fulfil the objectives of forest conversion,i.e.,establishing and safeguarding a diverse tree regeneration to promote the development of mature mixed forests in the future.
文摘Sorghum breeding significantly relies on the understanding of genetic diversity dynamics. Despite its importance, research on the geographical distribution of essential agro-morphological and phenological traits for achieving targeted breeding outcomes has been limited. This paper presents an analysis of five key traits—stem flavor, days to 50% maturity, plant height, grain color, and grain size—across 483 germplasm samples from 71 villages in Niger, based on data collected during a 2003 survey. The primary aim is to map the geographical distribution of these traits. The findings, illustrated on a map of Niger, provide insights into the regional distribution of these characteristics, aiding breeders and agronomists in understanding trait combinations for developing new sorghum varieties.
基金supported by the United States Department of Agriculture, USDA-CSREES, Evans-Allen, Project number: MOX-NKONGOLO, Accession #:0208180
文摘Fluctuations of greenhouse gases emissions and soil properties occur at short spatial and temporal scales, however, results are often reported for larger scales studies. We monitored CO2, CH4, and N2O fluxes and soil temperature （T）, thermal conductivity （K）, resistivity （R） and thermal diffusivity （D） from 2004 to 2006 in a pasture. Soil air samples for determination of CO2, CH4 and N2O concentrations were collected from static and vented chambers and analyzed within two hours of collection with a gas chromatograph. T, K, R and D were measured in-situ using a KD2 probe. Soil samples were also taken for measurements of soil chemical and physical properties. The pasture acted as a sink in 2004, a source in 2005 and again a sink of CH4 in 2006. CO2 and CH4 were highest, but N2O as well as T, K and D were lowest in 2004. Only K was correlated with C02 in 2004 while T correlated with both N2O （r = 0.76, p = 0.0001） and CO2 （r = 0.88, p = 0.0001） in 2005. In 2006, all gases fluxes were significantly correlated with T, K and R when the data for the entire year were considered. However, an in-depth examination of the data revealed the existence of month-to-month shifts, lack of correlation and differing spatial structures. These results stress the need for further studies on the relationship between soil properties and gases fluxes. K and R offer a promise as potential controlling factors for greenhouse gases fluxes in this pasture.
文摘Wastewater treatment is a problem with much acuity in the city of Maradi in general, and particularly in the Communal District I of Maradi. It is for this reason that the present study was conducted which deals with wastewater sanitation. The main objective of this study conducted through a survey is to investigate in the domestic wastewater sanitation in the Communal District I of Maradi city. Specifically, the study aims to estimate the amount of wastewater produced by households and to analyze the sanitation system at household and at district levels. The wastewater management practices in this district were assessed through a descriptive cross sectional study in which a total of 129 households were selected by sample distribution technique in the district neighborhoods and studied using interviewer and administered questionnaires at communal and household levels. The results of the study showed that the amount of domestic wastewater generated is quite large, about 32.27 m3 per person per day, and this comes from several sources including showers, laundry, dishwashing and income generating activities. The results also revealed that the unhealthy state of the Communal District I of Maradi is related to the absence of a wastewater treatment system, the methods and practices used in its management, and the population is also largely responsible for this unhealthy state and not willing to participate to a sanitation project.
文摘The analysis of environmental impact effects on forest ecosystems has a theoretical and practical nature. Many methods have been developed to determine characteristics and intensity of this impact. Methodologically, they can be divided into three groups： environmental parameter, bioindicative and combined methods. To evaluate the environmental impact a combined method was used in this study, it was based on trees as the bioindicators and their response reactions, and environmental parameter analysis. In this study the bioindicator was Norway spruce （Picea abies （L.） Karst.）, whose response reaction was used to explain total impact volumes of environmental factors in different places in the region of Kurzeme and try to interpret the causes of these differences. As the bioindicators criterion was used response reaction of Norway spruce during a period of 20 years, which was expressed with cumulative and annual additional volume increment, and was depending on the location of the stand and its morphometric characteristics. The empirical material was collected in Kurzeme region in 28 sample plots that are located on two transects and in one reference stand. For the evaluation the widths of the last 40 year growth rings were measured. To express the environmental impact in Kurzeme region a multiple regression model was developed, which explains the environmental impact in the volume of 68.2%, the rest part can be explained by the local conditions of each stand. It must be noted that methodology used in this study is very sensitive, thus, each of the nuances in the dynamics of volume＇s annual reduced additional increments has biological and ecological cause.
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On the Equator, the Talihya North watershed is a vast area of nearly 581.7 km<sup>2</sup> that extends from the Cool Highlands on the Congo-Nile Crest in Lubero Territory to the Rift Valley in the Virunga National Park in Beni Territory. This vast territory has an agropastoral vocation. Indeed, agricultural activities combined with the high population density in this watershed generate modifications in the landscape structure. The objective of this paper is to study the dynamics of land use from 1987 to 2020. To achieve this, two Landsat TM+ and ETM+ images and one Sentinel-2 image were analyzed. After the classification of the images based on the Maximum Likelihood algorithm, this study shows that two processes are evident in the landscape of the North Talihya watershed: deforestation and savannization. Forests that occupied 253.11 km<sup>2</sup> in 1987 have decreased to 201.12 km<sup>2</sup> in 2001 and to 123.04 km<sup>2</sup> in 2020. These area balances indicate that the natural forest formations in the North Talihya watershed have been converted primarily to croplands and fallows. The estimated annual deforestation rate between 1987 and 2020 is 2.18%. With this high rate of deforestation, mechanisms to restore degraded forest ecosystems in this watershed will need to be put in place. The sustainable management of residual forest ecosystems that have escaped human pressure is necessary for the conservation of biodiversity for future generations.
文摘Water and its importance cannot be understated.Its greatest value lies in its ability and capacity to provide biological and environmental services.Water quality is an essential parameter to be studied when the overall focus is sustainable development keeping mankind at a focal point.The study assessed the water quality and its suitability for drinking purposes in most areas of Padada Watershed.In this study,nine identified sampling points were analyzed for different physico-chemical parameters such as turbidity,BOD(Biological Oxygen Demand),TSS(Total Solid Suspended),fecal coliform,pH,temperature,DO(Dissolved Oxygen),and SC(Specific Conductivity).Results found turbidity range from 0.74-19.7 NTU;BOD range from 0.04-2.2 mg/L;TSS range from 1-411 mg/L;fecal coliform range from<1.8-160,000 MPN/100mL.The temperature value ranges from 24.8-31.9°C;pH value ranges from 7.05-7.92;SC ranges from 119.7-551μS/cm while DO range from 4.87-8.14 mg/L.Moreover,the results revealed that most sampling sites exceeded the permissible limits.The highest concentration of fecal coliform indicates contamination which may cause possible human health infection.Thus,the water of Padada River Watershed is not potable for drinking and it is recommended to take beneficial steps to prevent adverse health effects to the community.
文摘The Urban Commune of Maradi in Niger experienced increasingly frequent flooding following rainy episodes generating volumes and water flows that are difficult to control in recent years. This study aims to determine the impacts of runoff water in Commune II of Maradi City and to assess the role of urban planning in runoff management, as well as the strengths and weaknesses of urban sanitation in Maradi. The methodological approach used consisted of: 1) an interpretation of documentary data, 2) gathering information on runoff at several sites in the study area, and 3) interviews and questionnaires with local communities. This approach made it possible to understand the degree of vulnerability of the populations to flooding and then to propose sustainable solutions to reduce the vulnerability of the affected populations, through the implementation of effective urban rainwater management practices (USWMP). The results show that the impacts of runoff are mainly related to the lack of adequate storm water drainage networks in the area, but also to the nature of the habitats. Geomorphological factors such as the nature of the soil, the slope of the terrain and the altitude increase the degree of risk. In addition, the inadequacy and dilapidation of the drainage systems of the canals and above all the anarchic occupation of the land linked to accelerated urbanization are the cause of flooding by stagnation of rainwater. A phenomenon now linked to numerous deteriorations of urban equipment, the runoff of rainwater in the city of Maradi carries so many pollutants that municipalities, businesses and individuals should put in place pollution prevention measures.
文摘Millet and maize play an important role in food and nutrition security in Ni-ger.Despite their importance both in terms of food and economics,these ce-real crops continue to face insect pests including the Fall armyworm,S.frugi-perda(Smith.,1797).This caterpillar appeared for the first time in 2016 in sub-Saharan Africa(Nigeria,Sao Tome,Benin and Togo)and the same year in Torodi in Niger.The Fall armyworm is present in all regions of Niger from where it attacks the main cereals.The damage caused by this pest poses a sig-nificant threat to the productivity of these crops.The objective of this study is to assess the incidence and severity of Fall armyworm damage on maize and millet in the Maradi region.The study was conducted at the station(INRAN)and in Djirataoua.Four(4)fields were chosen,population dynamics monitor-ing through Delta Traps for captures of adult males ofS.frugiperdaand larval scouting in the field.The“N”sampling technique was used to determine the natural S.frugiperdainfestation rate on corn(71.7%on maize produce in INRAN and 31.5%on maize produce in Djirataoua)and millet(17.4%on mil-let produce in Djirataoua and 7.8%on millet produce in INRAN).And the level of leaf damage recorded only scores 2 and 3 on millet and maize recorded up to score 7,measured using a method of the Davisetal.,(1992)Leaf Damage Assessment Scale/Score.These results will contribute to the development of an integrated management program for Fall armyworm.The main objective is to assess the impact of the fall armyworm,Spodopterafrugiperda(J.E.Smith),on maize and millet crops in the Maradi region.More specifically,the aim is to:1)Monitor fall armyworm population dynamics in the fields;2)De-termine the infestation rate ofS.frugiperdaon maize and millet;3)Assess the level of CLA leaf damage also on maize and millet.
