Proposed agroforestry options should begin with the species that farmers are most familiar with,which would be the native multipurpose trees that have evolved under smallholder farms and socioeconomic conditions.The A...Proposed agroforestry options should begin with the species that farmers are most familiar with,which would be the native multipurpose trees that have evolved under smallholder farms and socioeconomic conditions.The African birch(Anogeissus leiocarpa(DC.)Guill.&Perr.)and pink jacaranda(Stereospermum kunthianum Cham.)trees are the dominant species in the agroforestry parkland system in the drylands of Tigray,Ethiopia.Smallholder farmers highly value these trees for their multifunctional uses including timber,firewood,charcoal,medicine,etc.These trees also could improve soil fertility.However,the amount of soil physical and chemical properties enhanced by the two species must be determined to maintain the sustainable conservation of the species in the parklands and to scale up to similar agroecological systems.Hence,we selected twelve isolated trees,six from each species that had similar dendrometric characteristics and were growing in similar environmental conditions.We divided the canopy cover of each tree into three radial distances:mid-canopy,canopy edge,and canopy gap(control).At each distance,we took soil samples from three different depths.We collected 216 soil samples(half disturbed and the other half undisturbed)from each canopy position and soil depth.Bulk density(BD),soil moisture content(SMC),soil organic carbon(SOC),total nitrogen(TN),available phosphorus(AP),available potassium(AK),p H,electrical conductivity(EC),and cation exchange capacity(CEC)were analysed.Results revealed that soil physical and chemical properties significantly improved except for soil texture and EC under both species,CEC under A.leiocarpus,and soil p H under S.kunthianum,all the studied soils were improved under both species canopy as compared with canopy gap.SMC,TN,AP,and AK under canopy of these trees were respectively 24.1%,11.1%,55.0%,and 9.3% higher than those soils under control.The two parkland agroforestry species significantly enhanced soil fertility near the canopy of topsoil through improving soil physical and chemical properties.These two species were recommended in the drylands with similar agro-ecological systems.展开更多
In this study, the roles of indigenous knowledge and farmers’ perception of natural resources management were analyzed. A total of seventy households were selected by simple random sampling with replacement method fo...In this study, the roles of indigenous knowledge and farmers’ perception of natural resources management were analyzed. A total of seventy households were selected by simple random sampling with replacement method for collection of data. Formal interviews were conducted to the 5% plus of households in the study area in addition to the focus group discussions and qualitative field observations. It was expressed by 98.6% of the total respondents that “Sera” which is the traditional practice has being used to manage natural resources in the study area. In the “Sera” systems, individuals are excluded a punishment from any kind of social interaction in a response to their unlawful action in the community natural resources. It was indicated by 84.3% of respondents that deforestation and related problems are the major challenges including grazing and shortage of farm size for the management of the culturally protected forest in the study area. The majority of the respondents (77.1%) believed that soil fertility decline in the study area. Development of effective participatory forest management and encouragement and supporting the traditional method of natural resources management is required to ensure the preservation and protection of these areas essential to ecosystem service provision, provide high biodiversity value and cultural heritage, and maintain the sustainability of culturally protected forest.展开更多
Alfalfa (Medicago sativa L.) is an important forage and conservation crop in North America but occurrences of naturalized alfalfa in rangelands are rare. A naturalized population of yellow-flowered alfalfa in mixed-gr...Alfalfa (Medicago sativa L.) is an important forage and conservation crop in North America but occurrences of naturalized alfalfa in rangelands are rare. A naturalized population of yellow-flowered alfalfa in mixed-grass prairie on the Grand River National Grassland in South Dakota has potential agricultural value for the region. Despite this value, the distribution pattern of this alfalfa among and within native plant communities in the northern Great Plains is unknown. Field studies were conducted from 2003 through 2006 along topographic positions at two sites where yellow-flowered alfalfa was naturalized to evaluate the relationships of yellow-flowered alfalfa on biomass production, cover, species diversity, and alfalfa seedbank distribution characteristics. High yellow-flowered alfalfa cover (>50%) was associated with increased total biomass and occurred exclusively in swales and toeslopes that had silty loam soils. However, species diversity and non-alfalfa biomass were reduced when yellow-flowered alfalfa cover was high. Yellow-flowered alfalfa cover was lower and species richness was higher on backslopes and shoulder areas where sandy loam soils were present. A strong positive linear association existed between yellow-flowered alfalfa cover and alfalfa seedbank density (r values ranged from 0.76 to 0.82, P < 0.0001). Greater than 99% of the seeds were viable but germination rate was only 4%, indicating a high percentage of hard seed in this alfalfa population. Naturalized yellow-flowered alfalfa was a dominant component of a stable, low diversity plant community composed of mainly introduced species in rich soils of swales/toeslopes that contributed to forage production and quality in mixed-grass prairie in the northern Great Plains.展开更多
Weeds cause significant production losses estimated at 25%in tropical countries and constitute main factor limiting rice production in Madagascar.This research,which was conducted at Anosibe-Ifanja(Antananarivo,Madaga...Weeds cause significant production losses estimated at 25%in tropical countries and constitute main factor limiting rice production in Madagascar.This research,which was conducted at Anosibe-Ifanja(Antananarivo,Madagascar),aims to propose the most cost-effective weed management strategies for both irrigated and rainfed rice system to improve rice production.To make the management of these potential rice weeds effective,two cultural practices were tested as good agricultural and farmers’practices on two rice systems.A phytoecological study and a floristic inventory were carried out on test plots,followed by an economic profitability analysis of management strategies.In rainfed rice,a greater number of species were inventoried(42 species in 14 families)than in irrigated rice(37 species in 9 families).The most important families found in both systems were Poaceae and Cyperaceae.But in rainfed rice,two other families are also dominant:Fabaceae and Asteraceae.The study on weed management strategy showed that adoption of in-season and out-of-season tillage combined with regular weeding is effective for weed control in irrigated rice.As far as rainfed rice is concerned,improved farming practice by integrating in-season tillage with aerial ploughing combined with the use of pre-emergence herbicide pendimethalin is more cost-effective.This research has resulted in an in-depth knowledge of rice weeds and weed control strategies that are only feasible with mechanization or animal traction.展开更多
The economy of Ethiopia has prospered for many years on agricultural products but currently, the country expands to industrialization and service providing for additional incomes. However, the wildlife tourism and con...The economy of Ethiopia has prospered for many years on agricultural products but currently, the country expands to industrialization and service providing for additional incomes. However, the wildlife tourism and conservation practices are still at low attention. Therefore, this review paper identifies potential opportunities and wildlife diversity to promote wildlife tourism practices in Ethiopia. Furthermore, it also identifies the challenges and future directions to put into practice for future wildlife tourism industry. Wildlife tourism is one of the best potential economies to the country due to the presence of magnificent diversity of wildlife with high endemism and expansion of protected areas. The main intentions of tourists are to visit large mammals and birds with their natural habitats. The country earns million dollars per year only from protected areas through nature based tourism. The Montane and Afroalpine, Rift Valley and Transboundary ecosystem, a world class icon for wildlife tourism which attracts various tourists, and potential tourism destination for Ethiopia due to its high mammalian diversity and scenic area. The expansion of protected areas, peaceful and friendly people, and endemism promote tourism industry in Ethiopia. Even though, Ethiopia is the third country next to Tanzania and Uganda in terms of land surface of protected area;human-wildlife conflict, loss of biodiversity, and limited tourism and conservation attention with poor infrastructure are some of the major challenges. To scale up wildlife tourism industry, better promotion with practical conservation practices, community based tourism approaches and infrastructures should be implemented throughout the whole area of tourist destination.展开更多
Ecosystem services(ES)are the connection between nature and society,and are essential for the well-being of local communities that depend on them.In Ethiopia,church forests and the surrounding agricultural matrix supp...Ecosystem services(ES)are the connection between nature and society,and are essential for the well-being of local communities that depend on them.In Ethiopia,church forests and the surrounding agricultural matrix supply numerous ES.However,the ES delivered by both land use types have not yet been assessed simultaneously.Here we surveyed both church forests and their agricultural matrices,aiming to quantify,compare and unravel the drivers underlying tree-based ES supply,density and multifunctionality.We found that almost all church forests and half of the agricultural matrices provided high ES densities.ES multifunctionality was higher in the agricultural matrices,suggesting that people deliberately conserve or plant multifunctional tree species.Furthermore,the supply of all categories of ES was positively correlated with church forest age(p-value<0.001)in the agricultural matrix,while the extent of church forest was positively correlated with the density of all categories ecosystem services score in the church forests(p-value<0.001).Our results can be used to prioritize conservation efforts at sites that provide high levels of ES supply,ES density and ES multifunctionality,and to prioritize restoration efforts at sites with low levels thereof.展开更多
Studies on mainstreaming climate-smart agriculture(CSA)practices can increase smallholder farmers’capacity and awareness to improve food security and establish sustainable livelihoods through resilient agricultural s...Studies on mainstreaming climate-smart agriculture(CSA)practices can increase smallholder farmers’capacity and awareness to improve food security and establish sustainable livelihoods through resilient agricultural systems,while achieving adaptation and mitigation benefits.Hence,valuable insights can be obtained from smallholder farmers in responding to present and forthcoming challenges of climate change impacts.However,there is little research work on trade-off and synergy assessments.Taking Geshy watershed in Southwest Ethiopia as a case study area,both quantitative and qualitative data analysis were undertaken in this study.The data were collected from 15 key informant interviews,6 focus group discussions,and 384 households to answer the following questions:(1)what are the top 5 preferred CSA practices for smallholder farmers in Geshy watershed when coping with the impacts of climate change?(2)What is the performance of the preferred CSA practices?And(3)which trade-offs and synergies are experienced upon the implementation of CSA practices?The study came up with the most preferred CSA practices such as the use of improved crop varieties,small-scale irrigation,improved animal husbandry,the use of efficient inorganic fertilizers,and crop rotation with legumes.The selected CSA practices showed that the productivity goal exhibit the best synergy,while the mitigation goal has trade-offs.The study also indicated that the use of improved crop varieties causes high synergies in all 3 goals of CSA practices;small-scale irrigation provides a medium synergy on productivity goal but high synergy for adaptation and mitigation goals;improved animal husbandry shows a high synergy with the adaptation goal,a relatively lower synergy with the productivity goal,and a trade-off with the mitigation goal;the use of efficient inorganic fertilizers shows maximum synergy for the productivity and adaptation goals;and crop rotation with legumes exhibits high synergy with the productivity and mitigation goals but a relatively lower synergy with the adaptation goal.These results can provide evidence to various stakeholder farmers in the value chain that the impacts of climate change can be addressed by the adoption of CSA practices.In general,CSA practices are considered indispensable.Smallholder farmers prefer CSA practices that help to increase crop productivity and household resilience to climate change impacts.The results generate a vital foundation for recommendations to smallholder farming decision-makers.It also sensitizes actions for innovative and sustainable methods that are able to upscale the preferred CSA practices in the agricultural system in Geshy watershed of Southwest Ethiopia and other regions.展开更多
Land suitability analysis of Moringa oleifera tree cultivation is important to enhance its product,as the demand forthis tree for medicinal values and food sources is increasing worldwide.Therefore,this study aimed to...Land suitability analysis of Moringa oleifera tree cultivation is important to enhance its product,as the demand forthis tree for medicinal values and food sources is increasing worldwide.Therefore,this study aimed to assess suitableland for Moringa oleifera tree cultivation by using the integration of multi-criteria evaluation with geospatialtechnologies in the Dhidhessa catchment,western Ethiopia.Five parameters,namely:slope,land use and landcover(LULC),soil texture,land surface temperature,and rainfall data,were used in this study.The land suitabilityevaluation of Moringa oleifera is classified into three classes as highly suitable,moderately suitable,and notsuitable.The results revealed that,about 344.4 km2(12.2%)of the area is categorized into highly suitable,and2343.7 km2(83%)is moderately suitable for Moringa tree,whereas,137.2 km2(4.9%)is categorized as notsuitable for Moringa oleifera tree cultivation.Hence,based on the finding of the study,we suggested that farmers andother stakeholders can cultivate Moringa oleifera trees in the Dhidhessa catchment.展开更多
Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence ...Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence of canopy gap size and the relationship of gap regime attributes to diversity measures and regeneration. The average gap size in the study area was found to be 396 m2 and around half of gaps were 4–8 years old. Gaps created by natural single tree fall were smaller in size but significantly higher in number. Diversity and regeneration of woody species were compared with canopy gaps and intact vegetation. Species richness and diversity was higher in gaps than in intact vegetation. Macaranga peltata, a shade intolerant species dominated gaps while intact vegetation was dominated by shade tolerant Kingiodendron pinnatum.Gap size significantly influenced species diversity and regeneration. Gap area and age were significantly and negatively correlated with diversity measures but positively correlated with regeneration. Among all the attributes of gaps, regeneration was significantly positively correlated with light intensity. Gaps maintained species diversity and favored regeneration of woody species. In addition to gap size and age, other gap ecological attributes also affected species diversity and regeneration.展开更多
Allometric equations are important for quantifying biomass and carbon storage in terrestrial forest ecosystems.However,equations for dry deciduous woodland ecosystems,an important carbon sink in the lowland areas of E...Allometric equations are important for quantifying biomass and carbon storage in terrestrial forest ecosystems.However,equations for dry deciduous woodland ecosystems,an important carbon sink in the lowland areas of Ethiopia have not as yet been developed.This study attempts to develop and evaluate species-specific allometric equations for predicting aboveground biomass(AGB)of dominant woody species based on data from destructive sampling for Combretum collinum,Combretum molle,Combretum harotomannianum,Terminalia laxiflora and mixed-species.Diameter at breast height ranged from 5 to 30 cm.Two empirical equations were developed using DBH(Eq.1)and height(Eq.2).Equation 2 gave better AGB estimations than Eq.1.The inclusion of both DBH and H were the best estimate biometric variables for AGB.Further,the equations were evaluated and compared with common generic allometric equations.The result showed that our allometric equations are appropriate for estimating AGB.The development and application of empirical species-specific allometric equations is crucial to improve biomass and carbon stock estimation for dry woodland ecosystems.展开更多
The impact of inputs on farm production growth was evaluated by analyzing the economic data of the upper and middle parts of the Yellow River basin,China for the period of 1980-1999.Descriptive statistics were employe...The impact of inputs on farm production growth was evaluated by analyzing the economic data of the upper and middle parts of the Yellow River basin,China for the period of 1980-1999.Descriptive statistics were employed to characterize the temporal trends and spatial patterns in farm production and five pertinent inputs of cultivated cropland,irrigation ratio, agricultural labor,machinery power and chemical fertilizer.Stochastic frontier production function was applied to quantify the dependence of the farm production on these inputs.The growth of farm production was decomposed to reflect the contributions by input growths and change in total factor productivity.The change in total factor productivity was further decomposed into the changes in technology and in technical efficiency.The gross value of farm production in the region of study increased by 1.6 fold during 1980-1999.Among the five selected farm inputs,machinery power and chemical fertilizer increased by 1.8 and 2.8 fold,respectively.The increases in cultivated cropland,irrigated cropland,and agricultural labor were all less than 0.16 fold.The growth in the farm production was primarily contributed by the increase in the total factor productivity during 1980-1985,and by input growths after 1985.More than 80% of the contributions by input growths were attributed to the increased application of fertilizer and machinery.In the change of total factor productivity,the technology change dominated over the technical efficiency change in the study period except in the period of 1985-1990,implying that institution and investment played important roles in farm production growth.There was a decreasing trend in the technical efficiency in the region of study,indicating a potential to increase farm production by improving the technical efficiency in farm activities.Given the limited natural resources in the basin,the results of this study suggested that,for a sustainable growth of farm production in the area,efforts should be directed to technology progress and improvement in technical efficiency in the use of available resources.展开更多
Aquaculture is a rapidly growing global agriculture sector and the importance of fish health has become of upmost importance as production levels and stocking densities increase. Over the past few decades, there have ...Aquaculture is a rapidly growing global agriculture sector and the importance of fish health has become of upmost importance as production levels and stocking densities increase. Over the past few decades, there have been a large number of immunological investigations on commonly cultured finfish species. Further, new technologies and strategies that embody use of fish immunostimulants, probiotics, and vaccinology rely heavily upon a comprehensive understanding of teleost immune system mechanics. The teleost immune system works in concert to properly recognize, control, and clear aquatic pathogens. Recent findings have exemplified the cooperative efforts of the nonspecific and adaptive branches, and have put forth an emphasis on the importance of the mucosal immune response in all aspects of a mounted immune response. This review provides a generalized overview of the innate and adaptive arms of the fish immune system, and provides highlights of recently published work in the areas of signaling networks and mucosal immune interactions.展开更多
Soil labile organic carbon(C) plays an important role in improving soil quality. The relatively stable fractions of soil organic C(SOC) represent the bulk of SOC, and are also the primary determinant of the long-term ...Soil labile organic carbon(C) plays an important role in improving soil quality. The relatively stable fractions of soil organic C(SOC) represent the bulk of SOC, and are also the primary determinant of the long-term C balance of terrestrial ecosystems. Different land use types can influence the distribution patterns of different SOC fractions. However, the underlying mechanisms are not well understood. In the present study, different fractions of SOC were determined in two land use types: a grazed grassland(established on previously cultivated cropland 25 years ago, GG) and a long-term cultivated millet cropland(MC). The results showed that C concentration and C storage of light fractions(LF) and heavy fractions(HF) presented different patterns along the soil profiles in the two sites. More plant residues in GG resulted in 91.9% higher LF storage at the 0–10 cm soil depth, further contributed to 21.9% higher SOC storage at this soil depth; SOC storage at 20–60 cm soil depth in MC was 98.8% higher than that in GG, which could be mainly attributed to the HF storage 104.5% higher than in GG. This might be caused by the long-term application of organic manure, as well as the protection from plough pan and silt- and clay-sized particles. The study indicated that different soil management practices in this region can greatly influence the variations of different SOC fractions, while the conventional tillage can greatly improve the storage of SOC by increasing heavy fractions.展开更多
In developing countries such as Ethiopia, research to develop and promote soil and water conservation practices rarely addressed regional diversity. Using a water-balance approach in this study, we used runoff plots f...In developing countries such as Ethiopia, research to develop and promote soil and water conservation practices rarely addressed regional diversity. Using a water-balance approach in this study, we used runoff plots from three sites, each representing a different agro-ecological environment, e.g., high, mid and low in both elevation and rainfall, in the Upper Blue Nile Basin of Ethiopia to examine the runoff response and runoff conservation efficiency of a range of different soil and water conservation measures and their impacts on soil moisture. The plots at each site represented common land use types(cultivated vs. non-agricultural land use types) and slopes(gentle and steep). Seasonal runoff from control plots in the highlands ranged 214–560 versus 253–475 mm at midlands and 119–200 mm at lowlands. The three soil and water conservation techniques applied in cultivated land increased runoff conservation efficiency by 32% to 51%, depending on the site. At the moist subtropical site in a highland region, soil and water conservation increased soil moisture enough to potentially cause waterlogging, which was absent at the lowrainfall sites. Soil bunds combined with Vetiveria zizanioides grass in cultivated land and short trenches in grassland conserved the most runoff(51% and 55%, respectively). Runoff responses showed high spatial variation within and between land use types, causing high variation in soil and water conservation efficiency. Our results highlight the need to understand the role of the agro-ecological environment in the success of soil and water conservation measures to control runoff and hydrological dynamics. This understanding will support policy development to promote the adoption of suitable techniques that can be tested at other locations with similar soil, climatic, and topographic conditions.展开更多
Land cover is a fundamental variable that links many facets of the natural environment and a key driver of global environmental change.Alterations in its status can have significant ramifications at local,regional and...Land cover is a fundamental variable that links many facets of the natural environment and a key driver of global environmental change.Alterations in its status can have significant ramifications at local,regional and global levels.Hence,it is imperative to map land cover at a range of spatial and temporal scales with a view to understanding the inherent patterns for effective characterization,prediction and management of the potential environmental impacts.This paper presents the results of an effort to map land cover patterns in Kinangop division,Kenya,using geospatial tools.This is a geographic locality that has experienced rapid land use transformations since Kenya's independence culminating in uncontrolled land cover changes and loss of biodiversity.The changes in land use/cover constrain the natural resource base and presuppose availability of quantitative and spatially explicit land cover data for understanding the inherent patterns and facilitating specific and multi-purpose land use planning and management.As such,the study had two objectives viz.(i) mapping the spatial patterns of land cover in Kinangop using remote sensing and GIS and;(ii) evaluating the quality of the resultant land cover map.ASTER satellite imagery acquired in January 23,2007 was procured and field data gathered between September l0 and October 16,2007.The latter were used for training the maximum likelihood classifier and validating the resultant land cover map.The land cover classification yielded 5 classes,overall accuracy of 83.5%and kappa statistic of 0.79,which conforms to the acceptable standards of land cover mapping. This qualifies its application in environmental decision-making and manifests the utility of geospatial techniques in mapping land resources.展开更多
Over the last 40 years, it has been shown at the global level that sustainable forestry can be achieved through comprehensive forest management,with the decentralized institutional arrangements of community-managed fo...Over the last 40 years, it has been shown at the global level that sustainable forestry can be achieved through comprehensive forest management,with the decentralized institutional arrangements of community-managed forestry coordinated by effective policy implementation. However, there is still a shortage of evidence regarding whether communitybased forestry is well characterized by forest policies,assessing what action is most needed and how best to address the challenges faced by community-based forestry in halting deforestation and promoting rural livelihoods. The study analyzed experts' assessments of the characteristics and success of communitymanaged forestry in Cambodia and explored three case studies of community-managed forestry practice to identify priorities for addressing forest policy implementation inadequacies in halting deforestation and promoting rural livelihoods. There were two methods of data collection. Firstly, this study used a survey of 27 experts to analyze perceptions about how far forest policy supported community-managed forestry effectively, the major challenges faced by the national community-managed forestry program, and the community-managed forestry contribution to halting deforestation and reducing rural poverty.Secondly, data was collected by content analysis of three case studies to explore the knowledge and practical experience of local experts about community-managed forestry practice at local level.The study employed Kendall's Coefficient of Concordance to analyze the level of concordance of experts on related forest policies(n=15) considering community-managed forestry, the challenges faced by the national community-managed forestry program,and the actions required to enable communitymanaged forestry to support communities. Analysis revealed that experts were in moderate agreement,denoted by Kendall's W=0.152, on how well forest policies articulate and implement the characteristics of community-managed forestry. Ranking of the major challenges faced by the national communitymanaged forestry program yielded Kendall's W of0.104, indicating the confidence in the ranking among experts was fair. There was only low confidence in the ranking of the action needed, with Kendall's W of0.055. Content analysis of the three case studies examining local experts' opinions on the attributes of community-managed forestry concerning the access,local participation and protection of the sustainable forestry revealed that Attribute one ‘Local people have access to the forest land and forest resources', and Attribute three ‘Local people begin by protecting and restoring the forests', received high attention from local experts. Of lesser importance or agreement was attributing two: local participation in decision-making concerning the forest.展开更多
This 121-day experiment evaluated the rearing performance of brown trout Salmo trutta fed one of two isonitrogenous and isocaloric diets and reared at velocities of either 2.8 or 16.1 cm/s. Fishmeal was the primary pr...This 121-day experiment evaluated the rearing performance of brown trout Salmo trutta fed one of two isonitrogenous and isocaloric diets and reared at velocities of either 2.8 or 16.1 cm/s. Fishmeal was the primary protein source for the reference diet, and bioprocessed soybean meal replaced approximately 67% of the fishmeal in the experimental diet. At the end of the experiment, there were no significant differences in gain, percent gain, feed conversion rates, or specific growth rates between the dietary treatments. There were also no significant differences in intestinal morphology, splenosomatic, hepatosomatic, and viscerosomatic indices related to diet composition. However, gain, percent gain, feed fed, and specific growth rate were all significantly greater in brown trout reared at the higher velocity. No significant differences in any of the other variables measured were observed between the velocity treatments. There were no significant interactions between diet and velocity in any of the variables. Based on the results of this study, bioprocessed soybean meal can replace at least 67% of the fishmeal in brown trout diets, regardless of the rearing velocities used in this study. However, higher rearing velocities are recommended to maximize juvenile brown trout growth rates.展开更多
Genetic parameters were evaluated for growth and cone characteristics(tree height,diameter at breast height,volume,cone number,thousand seeds weight and single cone seeds weight)on 86 half-sib families of Pinus koraie...Genetic parameters were evaluated for growth and cone characteristics(tree height,diameter at breast height,volume,cone number,thousand seeds weight and single cone seeds weight)on 86 half-sib families of Pinus koraiensis aged 31 years.Analyses of variance revealed significant differences(p<0.001)in all growth and cone traits among families while no significant differences were detected among blocks and the interaction between blocks and families.The average family values for growth traits were 17.22 m,8.67 cm and 0.43 m^(3) for tree height,diameter at breast height and volume,respectively.The average cone number,thousand seeds weight and single cone seeds weight were 17.57,748.91 g and 77.25 g,respectively.Genotypic additive variance and phenotypic variances ranged from 0.00009 to 3.820 and from 0.0005 to 23.066,while genotypic and phenotypic coefficients of variation ranged from 2.693%to 37.196%and 4.963%to 60.595%,respectively.Heritability at the individual and family level ranged from 0.152 to 0.215 and 0.611 to 0.862,respectively.Growth traits were significantly positively correlated with each other,but cone traits showed a weak correlation with growth traits.Based on 10% selection rate,nine families each were selected as elite materials in terms of high performance in volume and cone numbers,with 22.16%and 43.82%genetic gain in volume and cone number,respectively.These results provide beneficial information to select excellent families and establish orchards of P.koraiensis from improved seeds.展开更多
The prevailing farming system in Burkina Faso is smallholder agriculture based on cereal production, especially sorghum (Sorghum bicolor (L.) Moench) which form the staple diet for the population. Production is consta...The prevailing farming system in Burkina Faso is smallholder agriculture based on cereal production, especially sorghum (Sorghum bicolor (L.) Moench) which form the staple diet for the population. Production is constantly challenged by climate hazards, striga (Striga hermonthica (Del.) Benth.) infestation, inefficient farming practices and declining soil fertility. To address these concerns, one study on several agroecological techniques was conducted from 2013 to 2015 in a participative manner with more than 150 male and female farmers from four communities. Each farmer was asked to test out two or three agroecological techniques of his choice and to measure these new techniques against their usual farming practices. These techniques combined the use of organic fertilizer (5 t/ha) and/or mineral fertilizer (2 g/seed hole) with the systems of crop rotation and mixed cropping, in addition to the improved za? technique and the half-moon method. Plant material was composed of local landraces and improved varieties of sorghum, sesame and cowpea. On-farm application of agroecological techniques resulted in significantly increased sorghum production in all four communities. The rates of increase for grain yield were 8% for the half-moon fields and more than 130% for the rotation systems when compared to the farmers’ usual practices. More limited results were achieved with the chemical components of the soil after two years of experimentation. Only the soil’s organic matter showed improvement over the first year. This study shows that crop rotation, mixed cropping and the improved za? technique in combination with compost and improved drought-resistant varieties constitute agroecological strategies favorable to the intensification and diversification of farming systems in the studied locations. The farmers were above all impressed by the on-site management of compost by means of the za? technique which enabled large-scale fertilization of fields.展开更多
基金supported by the Sustainable Forest Management Project with the Local Communities in Tigray,northern Ethiopia,which was funded by the Norwegian Agency for Development Cooperation(NORAD)under the Norwegian Programme for Capacity Development in Higher EducationResearch for Development(NORHED)Programme(ETH 13/0018)+4 种基金the Ecological Organic Agriculture Project,Mekelle University,Ethiopiathe Institute of International Education-Scholars Rescue Fund(IIE-SRF)Norwegian University of Life Sciences(NMBU)Faculty of Environmental Sciences and Natural Resource Management(MINA)NORGLOBAL 2 Project in Ethiopia(303600)for supporting the research。
文摘Proposed agroforestry options should begin with the species that farmers are most familiar with,which would be the native multipurpose trees that have evolved under smallholder farms and socioeconomic conditions.The African birch(Anogeissus leiocarpa(DC.)Guill.&Perr.)and pink jacaranda(Stereospermum kunthianum Cham.)trees are the dominant species in the agroforestry parkland system in the drylands of Tigray,Ethiopia.Smallholder farmers highly value these trees for their multifunctional uses including timber,firewood,charcoal,medicine,etc.These trees also could improve soil fertility.However,the amount of soil physical and chemical properties enhanced by the two species must be determined to maintain the sustainable conservation of the species in the parklands and to scale up to similar agroecological systems.Hence,we selected twelve isolated trees,six from each species that had similar dendrometric characteristics and were growing in similar environmental conditions.We divided the canopy cover of each tree into three radial distances:mid-canopy,canopy edge,and canopy gap(control).At each distance,we took soil samples from three different depths.We collected 216 soil samples(half disturbed and the other half undisturbed)from each canopy position and soil depth.Bulk density(BD),soil moisture content(SMC),soil organic carbon(SOC),total nitrogen(TN),available phosphorus(AP),available potassium(AK),p H,electrical conductivity(EC),and cation exchange capacity(CEC)were analysed.Results revealed that soil physical and chemical properties significantly improved except for soil texture and EC under both species,CEC under A.leiocarpus,and soil p H under S.kunthianum,all the studied soils were improved under both species canopy as compared with canopy gap.SMC,TN,AP,and AK under canopy of these trees were respectively 24.1%,11.1%,55.0%,and 9.3% higher than those soils under control.The two parkland agroforestry species significantly enhanced soil fertility near the canopy of topsoil through improving soil physical and chemical properties.These two species were recommended in the drylands with similar agro-ecological systems.
文摘In this study, the roles of indigenous knowledge and farmers’ perception of natural resources management were analyzed. A total of seventy households were selected by simple random sampling with replacement method for collection of data. Formal interviews were conducted to the 5% plus of households in the study area in addition to the focus group discussions and qualitative field observations. It was expressed by 98.6% of the total respondents that “Sera” which is the traditional practice has being used to manage natural resources in the study area. In the “Sera” systems, individuals are excluded a punishment from any kind of social interaction in a response to their unlawful action in the community natural resources. It was indicated by 84.3% of respondents that deforestation and related problems are the major challenges including grazing and shortage of farm size for the management of the culturally protected forest in the study area. The majority of the respondents (77.1%) believed that soil fertility decline in the study area. Development of effective participatory forest management and encouragement and supporting the traditional method of natural resources management is required to ensure the preservation and protection of these areas essential to ecosystem service provision, provide high biodiversity value and cultural heritage, and maintain the sustainability of culturally protected forest.
文摘Alfalfa (Medicago sativa L.) is an important forage and conservation crop in North America but occurrences of naturalized alfalfa in rangelands are rare. A naturalized population of yellow-flowered alfalfa in mixed-grass prairie on the Grand River National Grassland in South Dakota has potential agricultural value for the region. Despite this value, the distribution pattern of this alfalfa among and within native plant communities in the northern Great Plains is unknown. Field studies were conducted from 2003 through 2006 along topographic positions at two sites where yellow-flowered alfalfa was naturalized to evaluate the relationships of yellow-flowered alfalfa on biomass production, cover, species diversity, and alfalfa seedbank distribution characteristics. High yellow-flowered alfalfa cover (>50%) was associated with increased total biomass and occurred exclusively in swales and toeslopes that had silty loam soils. However, species diversity and non-alfalfa biomass were reduced when yellow-flowered alfalfa cover was high. Yellow-flowered alfalfa cover was lower and species richness was higher on backslopes and shoulder areas where sandy loam soils were present. A strong positive linear association existed between yellow-flowered alfalfa cover and alfalfa seedbank density (r values ranged from 0.76 to 0.82, P < 0.0001). Greater than 99% of the seeds were viable but germination rate was only 4%, indicating a high percentage of hard seed in this alfalfa population. Naturalized yellow-flowered alfalfa was a dominant component of a stable, low diversity plant community composed of mainly introduced species in rich soils of swales/toeslopes that contributed to forage production and quality in mixed-grass prairie in the northern Great Plains.
文摘Weeds cause significant production losses estimated at 25%in tropical countries and constitute main factor limiting rice production in Madagascar.This research,which was conducted at Anosibe-Ifanja(Antananarivo,Madagascar),aims to propose the most cost-effective weed management strategies for both irrigated and rainfed rice system to improve rice production.To make the management of these potential rice weeds effective,two cultural practices were tested as good agricultural and farmers’practices on two rice systems.A phytoecological study and a floristic inventory were carried out on test plots,followed by an economic profitability analysis of management strategies.In rainfed rice,a greater number of species were inventoried(42 species in 14 families)than in irrigated rice(37 species in 9 families).The most important families found in both systems were Poaceae and Cyperaceae.But in rainfed rice,two other families are also dominant:Fabaceae and Asteraceae.The study on weed management strategy showed that adoption of in-season and out-of-season tillage combined with regular weeding is effective for weed control in irrigated rice.As far as rainfed rice is concerned,improved farming practice by integrating in-season tillage with aerial ploughing combined with the use of pre-emergence herbicide pendimethalin is more cost-effective.This research has resulted in an in-depth knowledge of rice weeds and weed control strategies that are only feasible with mechanization or animal traction.
文摘The economy of Ethiopia has prospered for many years on agricultural products but currently, the country expands to industrialization and service providing for additional incomes. However, the wildlife tourism and conservation practices are still at low attention. Therefore, this review paper identifies potential opportunities and wildlife diversity to promote wildlife tourism practices in Ethiopia. Furthermore, it also identifies the challenges and future directions to put into practice for future wildlife tourism industry. Wildlife tourism is one of the best potential economies to the country due to the presence of magnificent diversity of wildlife with high endemism and expansion of protected areas. The main intentions of tourists are to visit large mammals and birds with their natural habitats. The country earns million dollars per year only from protected areas through nature based tourism. The Montane and Afroalpine, Rift Valley and Transboundary ecosystem, a world class icon for wildlife tourism which attracts various tourists, and potential tourism destination for Ethiopia due to its high mammalian diversity and scenic area. The expansion of protected areas, peaceful and friendly people, and endemism promote tourism industry in Ethiopia. Even though, Ethiopia is the third country next to Tanzania and Uganda in terms of land surface of protected area;human-wildlife conflict, loss of biodiversity, and limited tourism and conservation attention with poor infrastructure are some of the major challenges. To scale up wildlife tourism industry, better promotion with practical conservation practices, community based tourism approaches and infrastructures should be implemented throughout the whole area of tourist destination.
基金flnancial support from VLIR-UOS,Belgium through the VLIR-IUC Interuniversity cooperation with Bahir Dar University,Ethiopia (BDU-IUC)
文摘Ecosystem services(ES)are the connection between nature and society,and are essential for the well-being of local communities that depend on them.In Ethiopia,church forests and the surrounding agricultural matrix supply numerous ES.However,the ES delivered by both land use types have not yet been assessed simultaneously.Here we surveyed both church forests and their agricultural matrices,aiming to quantify,compare and unravel the drivers underlying tree-based ES supply,density and multifunctionality.We found that almost all church forests and half of the agricultural matrices provided high ES densities.ES multifunctionality was higher in the agricultural matrices,suggesting that people deliberately conserve or plant multifunctional tree species.Furthermore,the supply of all categories of ES was positively correlated with church forest age(p-value<0.001)in the agricultural matrix,while the extent of church forest was positively correlated with the density of all categories ecosystem services score in the church forests(p-value<0.001).Our results can be used to prioritize conservation efforts at sites that provide high levels of ES supply,ES density and ES multifunctionality,and to prioritize restoration efforts at sites with low levels thereof.
文摘Studies on mainstreaming climate-smart agriculture(CSA)practices can increase smallholder farmers’capacity and awareness to improve food security and establish sustainable livelihoods through resilient agricultural systems,while achieving adaptation and mitigation benefits.Hence,valuable insights can be obtained from smallholder farmers in responding to present and forthcoming challenges of climate change impacts.However,there is little research work on trade-off and synergy assessments.Taking Geshy watershed in Southwest Ethiopia as a case study area,both quantitative and qualitative data analysis were undertaken in this study.The data were collected from 15 key informant interviews,6 focus group discussions,and 384 households to answer the following questions:(1)what are the top 5 preferred CSA practices for smallholder farmers in Geshy watershed when coping with the impacts of climate change?(2)What is the performance of the preferred CSA practices?And(3)which trade-offs and synergies are experienced upon the implementation of CSA practices?The study came up with the most preferred CSA practices such as the use of improved crop varieties,small-scale irrigation,improved animal husbandry,the use of efficient inorganic fertilizers,and crop rotation with legumes.The selected CSA practices showed that the productivity goal exhibit the best synergy,while the mitigation goal has trade-offs.The study also indicated that the use of improved crop varieties causes high synergies in all 3 goals of CSA practices;small-scale irrigation provides a medium synergy on productivity goal but high synergy for adaptation and mitigation goals;improved animal husbandry shows a high synergy with the adaptation goal,a relatively lower synergy with the productivity goal,and a trade-off with the mitigation goal;the use of efficient inorganic fertilizers shows maximum synergy for the productivity and adaptation goals;and crop rotation with legumes exhibits high synergy with the productivity and mitigation goals but a relatively lower synergy with the adaptation goal.These results can provide evidence to various stakeholder farmers in the value chain that the impacts of climate change can be addressed by the adoption of CSA practices.In general,CSA practices are considered indispensable.Smallholder farmers prefer CSA practices that help to increase crop productivity and household resilience to climate change impacts.The results generate a vital foundation for recommendations to smallholder farming decision-makers.It also sensitizes actions for innovative and sustainable methods that are able to upscale the preferred CSA practices in the agricultural system in Geshy watershed of Southwest Ethiopia and other regions.
文摘Land suitability analysis of Moringa oleifera tree cultivation is important to enhance its product,as the demand forthis tree for medicinal values and food sources is increasing worldwide.Therefore,this study aimed to assess suitableland for Moringa oleifera tree cultivation by using the integration of multi-criteria evaluation with geospatialtechnologies in the Dhidhessa catchment,western Ethiopia.Five parameters,namely:slope,land use and landcover(LULC),soil texture,land surface temperature,and rainfall data,were used in this study.The land suitabilityevaluation of Moringa oleifera is classified into three classes as highly suitable,moderately suitable,and notsuitable.The results revealed that,about 344.4 km2(12.2%)of the area is categorized into highly suitable,and2343.7 km2(83%)is moderately suitable for Moringa tree,whereas,137.2 km2(4.9%)is categorized as notsuitable for Moringa oleifera tree cultivation.Hence,based on the finding of the study,we suggested that farmers andother stakeholders can cultivate Moringa oleifera trees in the Dhidhessa catchment.
基金funded by the National Remote Sensing Centre,Hyderabad,India under NRSC-DOS-DBTGovt.of India project entitled‘‘Biodiversity Characterization in Southern parts of Karnataka’’(Project Number:UAS(B)/DR/GOI/245/2011-12)
文摘Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence of canopy gap size and the relationship of gap regime attributes to diversity measures and regeneration. The average gap size in the study area was found to be 396 m2 and around half of gaps were 4–8 years old. Gaps created by natural single tree fall were smaller in size but significantly higher in number. Diversity and regeneration of woody species were compared with canopy gaps and intact vegetation. Species richness and diversity was higher in gaps than in intact vegetation. Macaranga peltata, a shade intolerant species dominated gaps while intact vegetation was dominated by shade tolerant Kingiodendron pinnatum.Gap size significantly influenced species diversity and regeneration. Gap area and age were significantly and negatively correlated with diversity measures but positively correlated with regeneration. Among all the attributes of gaps, regeneration was significantly positively correlated with light intensity. Gaps maintained species diversity and favored regeneration of woody species. In addition to gap size and age, other gap ecological attributes also affected species diversity and regeneration.
文摘Allometric equations are important for quantifying biomass and carbon storage in terrestrial forest ecosystems.However,equations for dry deciduous woodland ecosystems,an important carbon sink in the lowland areas of Ethiopia have not as yet been developed.This study attempts to develop and evaluate species-specific allometric equations for predicting aboveground biomass(AGB)of dominant woody species based on data from destructive sampling for Combretum collinum,Combretum molle,Combretum harotomannianum,Terminalia laxiflora and mixed-species.Diameter at breast height ranged from 5 to 30 cm.Two empirical equations were developed using DBH(Eq.1)and height(Eq.2).Equation 2 gave better AGB estimations than Eq.1.The inclusion of both DBH and H were the best estimate biometric variables for AGB.Further,the equations were evaluated and compared with common generic allometric equations.The result showed that our allometric equations are appropriate for estimating AGB.The development and application of empirical species-specific allometric equations is crucial to improve biomass and carbon stock estimation for dry woodland ecosystems.
基金support was partially provided by the University of Connecticut Research Foundation,Storrs Agricultural Experiment Station,Chinese Academy of Sciences Outstanding Overseas Chinese Scholars Award,and the National Natural Science Foundation of China(40671071).
文摘The impact of inputs on farm production growth was evaluated by analyzing the economic data of the upper and middle parts of the Yellow River basin,China for the period of 1980-1999.Descriptive statistics were employed to characterize the temporal trends and spatial patterns in farm production and five pertinent inputs of cultivated cropland,irrigation ratio, agricultural labor,machinery power and chemical fertilizer.Stochastic frontier production function was applied to quantify the dependence of the farm production on these inputs.The growth of farm production was decomposed to reflect the contributions by input growths and change in total factor productivity.The change in total factor productivity was further decomposed into the changes in technology and in technical efficiency.The gross value of farm production in the region of study increased by 1.6 fold during 1980-1999.Among the five selected farm inputs,machinery power and chemical fertilizer increased by 1.8 and 2.8 fold,respectively.The increases in cultivated cropland,irrigated cropland,and agricultural labor were all less than 0.16 fold.The growth in the farm production was primarily contributed by the increase in the total factor productivity during 1980-1985,and by input growths after 1985.More than 80% of the contributions by input growths were attributed to the increased application of fertilizer and machinery.In the change of total factor productivity,the technology change dominated over the technical efficiency change in the study period except in the period of 1985-1990,implying that institution and investment played important roles in farm production growth.There was a decreasing trend in the technical efficiency in the region of study,indicating a potential to increase farm production by improving the technical efficiency in farm activities.Given the limited natural resources in the basin,the results of this study suggested that,for a sustainable growth of farm production in the area,efforts should be directed to technology progress and improvement in technical efficiency in the use of available resources.
文摘Aquaculture is a rapidly growing global agriculture sector and the importance of fish health has become of upmost importance as production levels and stocking densities increase. Over the past few decades, there have been a large number of immunological investigations on commonly cultured finfish species. Further, new technologies and strategies that embody use of fish immunostimulants, probiotics, and vaccinology rely heavily upon a comprehensive understanding of teleost immune system mechanics. The teleost immune system works in concert to properly recognize, control, and clear aquatic pathogens. Recent findings have exemplified the cooperative efforts of the nonspecific and adaptive branches, and have put forth an emphasis on the importance of the mucosal immune response in all aspects of a mounted immune response. This review provides a generalized overview of the innate and adaptive arms of the fish immune system, and provides highlights of recently published work in the areas of signaling networks and mucosal immune interactions.
基金supported by National Basic Research Program of China (2014CB138703)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA05050403)+3 种基金Changjiang Scholars and Innovative Research Team in University (IRT13019)Key Science and Technology Projects of Gansu Province (1203FKDA035)Fundamental Research Funds for the Central Universities (lzujbky-2014-78)the National Natural Science Foundation of China (31070412, 31201837)
文摘Soil labile organic carbon(C) plays an important role in improving soil quality. The relatively stable fractions of soil organic C(SOC) represent the bulk of SOC, and are also the primary determinant of the long-term C balance of terrestrial ecosystems. Different land use types can influence the distribution patterns of different SOC fractions. However, the underlying mechanisms are not well understood. In the present study, different fractions of SOC were determined in two land use types: a grazed grassland(established on previously cultivated cropland 25 years ago, GG) and a long-term cultivated millet cropland(MC). The results showed that C concentration and C storage of light fractions(LF) and heavy fractions(HF) presented different patterns along the soil profiles in the two sites. More plant residues in GG resulted in 91.9% higher LF storage at the 0–10 cm soil depth, further contributed to 21.9% higher SOC storage at this soil depth; SOC storage at 20–60 cm soil depth in MC was 98.8% higher than that in GG, which could be mainly attributed to the HF storage 104.5% higher than in GG. This might be caused by the long-term application of organic manure, as well as the protection from plough pan and silt- and clay-sized particles. The study indicated that different soil management practices in this region can greatly influence the variations of different SOC fractions, while the conventional tillage can greatly improve the storage of SOC by increasing heavy fractions.
基金supported by Grants-in-Aid for Scientific Research (25257417) from Japan Society for the Promotion of Science, Ministry of Education, Culture, Sports, Science and Technology, Japan
文摘In developing countries such as Ethiopia, research to develop and promote soil and water conservation practices rarely addressed regional diversity. Using a water-balance approach in this study, we used runoff plots from three sites, each representing a different agro-ecological environment, e.g., high, mid and low in both elevation and rainfall, in the Upper Blue Nile Basin of Ethiopia to examine the runoff response and runoff conservation efficiency of a range of different soil and water conservation measures and their impacts on soil moisture. The plots at each site represented common land use types(cultivated vs. non-agricultural land use types) and slopes(gentle and steep). Seasonal runoff from control plots in the highlands ranged 214–560 versus 253–475 mm at midlands and 119–200 mm at lowlands. The three soil and water conservation techniques applied in cultivated land increased runoff conservation efficiency by 32% to 51%, depending on the site. At the moist subtropical site in a highland region, soil and water conservation increased soil moisture enough to potentially cause waterlogging, which was absent at the lowrainfall sites. Soil bunds combined with Vetiveria zizanioides grass in cultivated land and short trenches in grassland conserved the most runoff(51% and 55%, respectively). Runoff responses showed high spatial variation within and between land use types, causing high variation in soil and water conservation efficiency. Our results highlight the need to understand the role of the agro-ecological environment in the success of soil and water conservation measures to control runoff and hydrological dynamics. This understanding will support policy development to promote the adoption of suitable techniques that can be tested at other locations with similar soil, climatic, and topographic conditions.
基金Special thanks are due to the Water Resources Management Authority (WRMA) and Ministry of Livestock and Fisheries Development in Kenya, the International Institute for Geo-information Science and Earth Observation (ITC) in Netherlands and European Union for logistical and financial support.
文摘Land cover is a fundamental variable that links many facets of the natural environment and a key driver of global environmental change.Alterations in its status can have significant ramifications at local,regional and global levels.Hence,it is imperative to map land cover at a range of spatial and temporal scales with a view to understanding the inherent patterns for effective characterization,prediction and management of the potential environmental impacts.This paper presents the results of an effort to map land cover patterns in Kinangop division,Kenya,using geospatial tools.This is a geographic locality that has experienced rapid land use transformations since Kenya's independence culminating in uncontrolled land cover changes and loss of biodiversity.The changes in land use/cover constrain the natural resource base and presuppose availability of quantitative and spatially explicit land cover data for understanding the inherent patterns and facilitating specific and multi-purpose land use planning and management.As such,the study had two objectives viz.(i) mapping the spatial patterns of land cover in Kinangop using remote sensing and GIS and;(ii) evaluating the quality of the resultant land cover map.ASTER satellite imagery acquired in January 23,2007 was procured and field data gathered between September l0 and October 16,2007.The latter were used for training the maximum likelihood classifier and validating the resultant land cover map.The land cover classification yielded 5 classes,overall accuracy of 83.5%and kappa statistic of 0.79,which conforms to the acceptable standards of land cover mapping. This qualifies its application in environmental decision-making and manifests the utility of geospatial techniques in mapping land resources.
基金the support of R&D Program for Forest Science Technology (Project No. 2014068E101819AA03) provided by Korea Forest Service (Korea Forestry Promotion Institute)
文摘Over the last 40 years, it has been shown at the global level that sustainable forestry can be achieved through comprehensive forest management,with the decentralized institutional arrangements of community-managed forestry coordinated by effective policy implementation. However, there is still a shortage of evidence regarding whether communitybased forestry is well characterized by forest policies,assessing what action is most needed and how best to address the challenges faced by community-based forestry in halting deforestation and promoting rural livelihoods. The study analyzed experts' assessments of the characteristics and success of communitymanaged forestry in Cambodia and explored three case studies of community-managed forestry practice to identify priorities for addressing forest policy implementation inadequacies in halting deforestation and promoting rural livelihoods. There were two methods of data collection. Firstly, this study used a survey of 27 experts to analyze perceptions about how far forest policy supported community-managed forestry effectively, the major challenges faced by the national community-managed forestry program, and the community-managed forestry contribution to halting deforestation and reducing rural poverty.Secondly, data was collected by content analysis of three case studies to explore the knowledge and practical experience of local experts about community-managed forestry practice at local level.The study employed Kendall's Coefficient of Concordance to analyze the level of concordance of experts on related forest policies(n=15) considering community-managed forestry, the challenges faced by the national community-managed forestry program,and the actions required to enable communitymanaged forestry to support communities. Analysis revealed that experts were in moderate agreement,denoted by Kendall's W=0.152, on how well forest policies articulate and implement the characteristics of community-managed forestry. Ranking of the major challenges faced by the national communitymanaged forestry program yielded Kendall's W of0.104, indicating the confidence in the ranking among experts was fair. There was only low confidence in the ranking of the action needed, with Kendall's W of0.055. Content analysis of the three case studies examining local experts' opinions on the attributes of community-managed forestry concerning the access,local participation and protection of the sustainable forestry revealed that Attribute one ‘Local people have access to the forest land and forest resources', and Attribute three ‘Local people begin by protecting and restoring the forests', received high attention from local experts. Of lesser importance or agreement was attributing two: local participation in decision-making concerning the forest.
文摘This 121-day experiment evaluated the rearing performance of brown trout Salmo trutta fed one of two isonitrogenous and isocaloric diets and reared at velocities of either 2.8 or 16.1 cm/s. Fishmeal was the primary protein source for the reference diet, and bioprocessed soybean meal replaced approximately 67% of the fishmeal in the experimental diet. At the end of the experiment, there were no significant differences in gain, percent gain, feed conversion rates, or specific growth rates between the dietary treatments. There were also no significant differences in intestinal morphology, splenosomatic, hepatosomatic, and viscerosomatic indices related to diet composition. However, gain, percent gain, feed fed, and specific growth rate were all significantly greater in brown trout reared at the higher velocity. No significant differences in any of the other variables measured were observed between the velocity treatments. There were no significant interactions between diet and velocity in any of the variables. Based on the results of this study, bioprocessed soybean meal can replace at least 67% of the fishmeal in brown trout diets, regardless of the rearing velocities used in this study. However, higher rearing velocities are recommended to maximize juvenile brown trout growth rates.
基金We are grateful to the Applied Technology Research and Development Planned Program of Heilongjiang Province(GA19B201-4)for supporting this research.
文摘Genetic parameters were evaluated for growth and cone characteristics(tree height,diameter at breast height,volume,cone number,thousand seeds weight and single cone seeds weight)on 86 half-sib families of Pinus koraiensis aged 31 years.Analyses of variance revealed significant differences(p<0.001)in all growth and cone traits among families while no significant differences were detected among blocks and the interaction between blocks and families.The average family values for growth traits were 17.22 m,8.67 cm and 0.43 m^(3) for tree height,diameter at breast height and volume,respectively.The average cone number,thousand seeds weight and single cone seeds weight were 17.57,748.91 g and 77.25 g,respectively.Genotypic additive variance and phenotypic variances ranged from 0.00009 to 3.820 and from 0.0005 to 23.066,while genotypic and phenotypic coefficients of variation ranged from 2.693%to 37.196%and 4.963%to 60.595%,respectively.Heritability at the individual and family level ranged from 0.152 to 0.215 and 0.611 to 0.862,respectively.Growth traits were significantly positively correlated with each other,but cone traits showed a weak correlation with growth traits.Based on 10% selection rate,nine families each were selected as elite materials in terms of high performance in volume and cone numbers,with 22.16%and 43.82%genetic gain in volume and cone number,respectively.These results provide beneficial information to select excellent families and establish orchards of P.koraiensis from improved seeds.
文摘The prevailing farming system in Burkina Faso is smallholder agriculture based on cereal production, especially sorghum (Sorghum bicolor (L.) Moench) which form the staple diet for the population. Production is constantly challenged by climate hazards, striga (Striga hermonthica (Del.) Benth.) infestation, inefficient farming practices and declining soil fertility. To address these concerns, one study on several agroecological techniques was conducted from 2013 to 2015 in a participative manner with more than 150 male and female farmers from four communities. Each farmer was asked to test out two or three agroecological techniques of his choice and to measure these new techniques against their usual farming practices. These techniques combined the use of organic fertilizer (5 t/ha) and/or mineral fertilizer (2 g/seed hole) with the systems of crop rotation and mixed cropping, in addition to the improved za? technique and the half-moon method. Plant material was composed of local landraces and improved varieties of sorghum, sesame and cowpea. On-farm application of agroecological techniques resulted in significantly increased sorghum production in all four communities. The rates of increase for grain yield were 8% for the half-moon fields and more than 130% for the rotation systems when compared to the farmers’ usual practices. More limited results were achieved with the chemical components of the soil after two years of experimentation. Only the soil’s organic matter showed improvement over the first year. This study shows that crop rotation, mixed cropping and the improved za? technique in combination with compost and improved drought-resistant varieties constitute agroecological strategies favorable to the intensification and diversification of farming systems in the studied locations. The farmers were above all impressed by the on-site management of compost by means of the za? technique which enabled large-scale fertilization of fields.
