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
Natural gas hydrate(NGH)has been widely considered as an alternative to conventional oil and gas resources in the future energy resource supply since Trofimuk’s first resource assessment in 1973.At least 29 global es...Natural gas hydrate(NGH)has been widely considered as an alternative to conventional oil and gas resources in the future energy resource supply since Trofimuk’s first resource assessment in 1973.At least 29 global estimates have been published from various studies so far,among which 24 estimates are greater than the total conventional gas resources.If drawn in chronological order,the 29 historical resource estimates show a clear downward trend,reflecting the changes in our perception with respect to its resource potential with increasing our knowledge on the NGH with time.A time series of the 29 estimates was used to establish a statistical model for predict the future trend.The model produces an expected resource value of 41.46×1012 m3 at the year of 2050.The statistical trend projected future gas hydrate resource is only about 10%of total natural gas resource in conventional reservoir,consistent with estimates of global technically recoverable resources(TRR)in gas hydrate from Monte Carlo technique based on volumetric and material balance approaches.Considering the technical challenges and high cost in commercial production and the lack of competitive advantages compared with rapid growing unconventional and renewable resources,only those on the very top of the gas hydrate resource pyramid will be added to future energy supply.It is unlikely that the NGH will be the major energy source in the future.展开更多
The Yuncheng Basin,located in the southern part of the Fenwei Rift,North China,exhibits obvious crust thinning(Moho uplift of 6-8 km)and shallow Curie point depth(less than 18 km)and hence holds great potential for ge...The Yuncheng Basin,located in the southern part of the Fenwei Rift,North China,exhibits obvious crust thinning(Moho uplift of 6-8 km)and shallow Curie point depth(less than 18 km)and hence holds great potential for geothermal resources.However,geothermal exploration within the Yuncheng Basin typically faces significant challenges due to civil and industrial noise from dense populations and industrial activities.To address these challenges,both Controlled-Source Audio-frequency Magnetotellurics(CSAMT)and radon measurements were employed in Baozigou village to investigate the geothermal structures and identify potential geothermal targets.The CSAMT method effectively delineated the structure of the subsurface hydrothermal system,identifying the reservoir as Paleogene sandstones and Ordovician and Cambrian limestones at elevations ranging from−800 m to−2500 m.In particular,two concealed normal faults(F_(a)and F_(b))were newly revealed by the combination of CSAMT and radon profiling;these previously undetected faults,which exhibit different scales and opposing dips,are likely to be responsible for controlling the convection of thermal water within the Basin’s subsurface hydrothermal system.Moreover,this study developed a preliminary conceptual geothermal model for the Fen River Depression within the Yuncheng Basin,which encompasses geothermal heat sources,cap rocks,reservoirs,and fluid pathways,providing valuable insights for future geothermal exploration.In conjunction with the 3D geological model constructed from CSAMT resistivity structures beneath Baozigou village,test drilling is recommended in the northwestern region of the Baozigou area to intersect the potentially deep fractured carbonates that may contain temperature-elevated geothermal water.This study establishes a good set of guidelines for future geothermal exploration in this region,indicating that high-permeability faults in the central segments of the Fen River Depression are promising targets.展开更多
Soil salinization may negatively affect microbial processes related to carbon dioxide （CO2） and nitrous oxide （N20） emissions. A short-term laboratory incubation experiment was conducted to investigate the effects...Soil salinization may negatively affect microbial processes related to carbon dioxide （CO2） and nitrous oxide （N20） emissions. A short-term laboratory incubation experiment was conducted to investigate the effects of soil electrical conductivity （EC） and moisture content on CO2 and N20 emissions from sulfate-based natural saline soils. Three separate 100-m long transects were established along the salinity gradient on a salt-affected agricultural field at Mooreton, North Dakota, USA. Surface soils were collected from four equally spaced sampling positions within each transect, at the depths of 0-15 and 15-30 cm. In the laboratory, artificial soil cores were formed combining soils from both the depths in each transect, and incubated at 60% and 90% water-filled pore space （WFPS） at 25 ~C. The measured depth-weighted EC of the saturated paste extract （ECe） across the sampling positions ranged from 0.43 to 4.65 dS m-1. Potential nitrogen （N） mineralization rate and CO2 emissions decreased with increasing soil ECe, but the relative decline in soil CO2 emissions with increasing ECe was smaller at 60% WFPS than at 90% WFPS. At 60% WFPS, soil N20 emissions decreased from 133 g N20-N kg-1 soil at ECe （ 0.50 dS m-1 to 72 μg N20-N kg-1 soil at ECe = 4.65 dS m-1. In contrast, at 90% WFPS, soil N20 emissions increased from 262 g N20-N kg-1 soil at ECe ： 0.81 dS m-1 to 849 g N20-N kg-1 soil at ECe ： 4.65 dS m-1, suggesting that N20 emissions were linked to both soil ECe and moisture content. Therefore, spatial variability in soil ECe and pattern of rainfall over the season need to be considered when up-scaling N20 and CO2 emissions from field to landscape scales.展开更多
Urbanization has caused significant landscape changes in rural areas,leading to the emergence of urbanized landscapes(ULs),which have been generally criticized by authorities and professionals.However,perceptions of U...Urbanization has caused significant landscape changes in rural areas,leading to the emergence of urbanized landscapes(ULs),which have been generally criticized by authorities and professionals.However,perceptions of ULs among local residents have rarely been studied.In this study,we chose five typical categories of ULs from rapidly transforming villages in Fujian Province,China–hardened water bank(HWB),big pavilion(BPA),big memorial arch(BMA),big ornamental lawn(BOL),and big square(BSQ)to do the study.We identified how these ULs were rated and ranked by on-site surveys,as well as how related aesthetic and multifunctional landscape characters(LCs)played a role.The results(N=550)showed that 1)residents supported the construction of ULs,and the most preferred category was that with the most natural elements(BOL)that was simultaneously well maintained.2)For the residents,the longer they had resided in the village and the fewer connections they had with the city,the more in favor they were of the ULs,and the more eager they were for landscape change.In addition,residents with higher education and Communist Party of China membership valued the naturalness related LCs more highly.3)Two contradictory preference features,naturalness and livability,should be well coordinated and balanced to construct an improved favorable village for the residents,to realize a balanced and sustainable development path.This study makes great theoretical contributions to landscape research and provides new insights into rural planning and construction.展开更多
Cassava-groundnut intercropping is not a common practice among smallholder farmers in Sierra Leone even though both crops are well suited for intercropping. On-farm trials were conducted in three locations (Bai Largor...Cassava-groundnut intercropping is not a common practice among smallholder farmers in Sierra Leone even though both crops are well suited for intercropping. On-farm trials were conducted in three locations (Bai Largor, Bassah, and Njala Kanima) in the Moyamba district during the 2021 cropping season to investigate the efficacy of cassava-groundnut intercropping for increasing crop productivity and soil organic carbon stock on smallholder farms in the Moyamba district, Southern Sierra Leone. The experimental design was a randomized complete block design in three replications with treatments of sole groundnut, sole cassava and cassava-groundnut intercropping. Data on the yield and yield components of cassava and groundnut were analysed using the PROC MIXED procedure of SAS 9.4 and means were compared using the standard error of difference (SED). The above-ground biomass, number of roots per plant, and fresh root yield of cassava were not significantly (p > 0.05) affected by the cassava-based cropping system. Averaged across locations, intercropping cassava with groundnut decreased the above-ground biomass, the number of roots per plant, and fresh root yield of cassava by 17%, 11%, and 17%, respectively. The above-ground biomass, number of pods per plant and fresh pod yield of groundnut were significantly (p 1), the highest net revenue and benefit-cost ratio. The benefit-cost ratio was also favourable for the sole cassava (BCR > 1) but not favourable for the sole groundnut (BCR < 1). Averaged across locations, intercropping cassava with groundnut increased the benefit-cost ratio by 121% and 13% when compared to the sole groundnut and sole cassava. In the event of a 40% yield loss for the cassava and groundnut, the benefit-cost ratio was favourable (1.12) only for the cassava groundnut intercropping system. The net soil organic carbon stock was favourable only for the cassava-groundnut intercrop. Averaged across locations, the net soil organic carbon for the cassava-groundnut intercropping increased by 3.4% when compared to the baseline within one cropping cycle of the cassava (12 months). The results confirm that cassava-groundnut intercropping is a sustainable land management practice that could enhance crop productivity and soil organic carbon stock on smallholder farms.展开更多
Centuries of forest exploitation have caused significant loss of natural forests in Europe,leading to a decline in populations for many species.To prevent further loss in biodiversity,the Norwegian government has set ...Centuries of forest exploitation have caused significant loss of natural forests in Europe,leading to a decline in populations for many species.To prevent further loss in biodiversity,the Norwegian government has set a target of protecting 10%of the forested area.However,recent data from the National Forest Inventory(NFI)reveals that less than 2%of Norway's forested area consists of natural forests.To identify forests with high conservation value,we used vertical and horizontal variables derived from airborne laser scanning(ALS)data,along with NFI plot measurements.Our study aimed to predict the presence of natural forests across three counties in southeastern Norway,using three different definitions:pristine,near-natural,and semi-natural forests.Natural forests are scarce,and their underrepresentation in field reference data can compromise the accuracy of the predictions.To address this,we assessed the potential gain of including additional field data specifically targeting natural forests to achieve a better balance in the dataset.Additionally,we examined the impact of stratifying the data by dominant tree species on the performance of the models.Our results revealed that semi-natural forests were the most accurately predicted,followed by near-natural and pristine forests,with Matthews correlation coefficient values of 0.32,0.24,and 0.17,respectively.Including additional field data did not improve the predictions.However,stratification by species improved the accuracy of predictions for near-natural and semi-natural forests,while reducing accuracy for pristine forests.The use of horizontal variables did not improve the predictions.Our study demonstrates the potential of ALS data in identifying forests with high conservation value.It provides a basis for further research on the use of ALS data for the detection and conservation of natural forests,offering valuable insights to guide future forest preservation efforts.展开更多
This research was carried out to evaluate the preference and adoption of harvesting, uprooting, stump burning, pruning and thinning practices for controlling the spread ofProsopisjuliflora （prosopis） within Marigat ...This research was carried out to evaluate the preference and adoption of harvesting, uprooting, stump burning, pruning and thinning practices for controlling the spread ofProsopisjuliflora （prosopis） within Marigat Division of the Baringo District, Kenya. A survey methodology was employed using a random sample of 25 Farmer Field School （FFS） members and 5 non=FFS members from each of the five locations of Marigat Division. In total, 100 FFS members and 25 non-FFS members participated in the study; addi- tional supplementary data were collected from the Kenya Forestry Research Institute （KEFRI）, a major facilitator and trainer of the identified FFS activities and practices in the study area since 2004. More than 80% of the local community never undertook any form of prosopis management practice; however, this changed after FFS training, indicating an acquisition and retention of knowledge which probably diffused to the non-FFS counterparts, through either formal or informal ways. Harvesting was the most preferred （100%） and stump burning the least preferred （46%） practice of managing the spread of prosopis. The success and preference of any prosopis management practice was attributed to wood and non-wood benefits derived from prosopis and growing of animal fodder and food crops on rehabilitated land. More than 80% of respondents attributed ineffectiveness of any prosopis management practice to coppicing and viable seed banks of the tree, while 50% highlighted a lack of consistency and integration in carrying out manage- ment practices. The reported negative attitude towards prosopis changed after training with none of the view to eradicate it. Labor intensity and frequent regeneration of seedlings were identified as the major challenges faced during the implementation of proso- pis management practices. In conclusion, the study shows that harvesting, uprooting, stump burning, pruning and thinning realized through consistent holistic integration contribute to containing the spread of prosopis trees in Baringo, Kenya.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
Forest degradation induced by intensive forest management and temperature increase by climate change are resulting in biodiversity decline in boreal forests.Intensive forest management and high-end climate emission sc...Forest degradation induced by intensive forest management and temperature increase by climate change are resulting in biodiversity decline in boreal forests.Intensive forest management and high-end climate emission scenarios can further reduce the amount and diversity of deadwood,the limiting factor for habitats for saproxylic species in European boreal forests.The magnitude of their combined effects and how changes in forest management can affect deadwood diversity under a range of climate change scenarios are poorly understood.We used forest growth simulations to evaluate how forest management and climate change will individually and jointly affect habitats of red-listed saproxylic species in Finland.We simulated seven forest management regimes and three climate scenarios(reference,RCP4.5 and RCP8.5)over 100 years.Management regimes included set aside,continuous cover forestry,business-as-usual(BAU)and four modifications of BAU.Habitat suitability was assessed using a speciesspecific habitat suitability index,including 21 fungal and invertebrate species groups.“Winner”and“loser”species were identified based on the modelled impacts of forest management and climate change on their habitat suitability.We found that forest management had a major impact on habitat suitability of saproxylic species compared to climate change.Habitat suitability index varied by over 250%among management regimes,while overall change in habitat suitability index caused by climate change was on average only 2%.More species groups were identified as winners than losers from impacts of climate change(52%–95%were winners,depending on the climate change scenario and management regime).The largest increase in habitat suitability index was achieved under set aside(254%)and the climate scenario RCP8.5(>2%),while continuous cover forestry was the most suitable regime to increase habitat suitability of saproxylic species(up to+11%)across all climate change scenarios.Our results show that close-to-nature management regimes(e.g.,continuous cover forestry and set aside)can increase the habitat suitability of many saproxylic boreal species more than the basic business-as-usual regime.This suggests that biodiversity loss of many saproxylic species in boreal forests can be mitigated through improved forest management practices,even as climate change progresses.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
Human well-being and livelihoods depend on natural ecosystem services(ESs).Following the increment of population,ESs have been deteriorated over time.Ultimately,land use/land cover(LULC)changes have a profound impact ...Human well-being and livelihoods depend on natural ecosystem services(ESs).Following the increment of population,ESs have been deteriorated over time.Ultimately,land use/land cover(LULC)changes have a profound impact on the change of ecosystem.The primary goal of this study is to determine the impacts of LULC changes on ecosystem service values(ESVs)in the upper Gilgel Abbay watershed,Ethiopia.Changes in LULC types were studied using three Landsat images representing 1986,2003,and 2021.The Landsat images were classified using a supervised image classification technique in Earth Resources Data Analysis System(ERDAS)Imagine 2014.We classified ESs in this study into four categories(including provisioning,regulating,supporting,and cultural services)based on global ES classification scheme.The adjusted ESV coefficient benefit approach was employed to measure the impacts of LULC changes on ESVs.Five LULC types were identified in this study,including cultivated land,forest,shrubland,grassland,and water body.The result revealed that the area of cultivated land accounted for 64.50%,71.50%,and 61.50%of the total area in 1986,2003,and 2021,respectively.The percentage of the total area covered by forest was 9.50%,5.90%,and 14.80%in 1986,2003,and 2021,respectively.Result revealed that the total ESV decreased from 7.42×10^(7) to 6.44×10^(7) USD between 1986 and 2003.This is due to the expansion of cultivated land at the expense of forest and shrubland.However,the total ESV increased from 6.44×10^(7) to 7.76×10^(7) USD during 2003-2021,because of the increment of forest and shrubland.The expansion of cultivated land and the reductions of forest and shrubland reduced most individual ESs during 1986-2003.Nevertheless,the increase in forest and shrubland at the expense of cultivated land enhanced many ESs during 2003-2021.Therefore,the findings suggest that appropriate land use practices should be scaled-up to sustainably maintain ESs.展开更多
Climate change impacts soil nitrogen, influencing plant responses to elevated atmospheric [CO2]. Understanding the interaction between nitrogen supply and elevated [CO2] is crucial for predicting plant future performa...Climate change impacts soil nitrogen, influencing plant responses to elevated atmospheric [CO2]. Understanding the interaction between nitrogen supply and elevated [CO2] is crucial for predicting plant future performance. This study examined the interactive effects of elevated [CO2] and nitrogen supply on the eco-physiological performance of yellow birch. Seedlings were exposed to two [CO2] levels and five nitrogen supply levels for 4 months. Growth parameters such as seedling height and root collar diameter increased with higher nitrogen supply and elevated [CO2], while specific leaf area decreased. [CO2] elevation and increasing nitrogen supply also increased the total and stem, and leaf biomass. The elevated [CO2] increased the stem mass ratio but decreased the root-to-shoot ratio and root mass ratio. However, decreases in nitrogen supply increased root mass ratio and root-to-shoot ratio. The elevated [CO2] increased the maximum rate of Rubisco carboxylation (Vcmax) and photosynthetic electron transport (Jmax), but the effect on Jmax was statistically significant only at the two highest nitrogen supply levels. The results indicate that yellow birch may increase photosynthetic capacity, biomass, and growth in the future when [CO2] is higher.展开更多
Site index(SI)is determined from the top height development and is a proxy for forest productivity,defined as the expected top height for a given species at a certain index age.In Norway,an index age of 40 years is us...Site index(SI)is determined from the top height development and is a proxy for forest productivity,defined as the expected top height for a given species at a certain index age.In Norway,an index age of 40 years is used.By using bi-temporal airborne laser scanning(ALS)data,SI can be determined using models estimated from SI observed on field plots(the direct approach)or from predicted top heights at two points in time(the height differential approach).Time series of ALS data may enhance SI determination compared to conventional methods used in operational forest inventory by providing more detailed information about the top height development.We used longitudinal data comprising spatially consistent field and ALS data collected from training plots in 1999,2010,and 2022 to determine SI using the direct and height differential approaches using all combinations of years and performed an external validation.We also evaluated the use of data assimilation.Values of root mean square error obtained from external validation were in the ranges of 16.3%–21.4%and 12.8%–20.6%of the mean fieldregistered SI for the direct approach and the height differential approach,respectively.There were no statistically significant effects of time series length or the number of points in time on the obtained accuracies.Data assimilation did not result in any substantial improvement in the obtained accuracies.Although a time series of ALS data did not yield greater accuracies compared to using only two points in time,a larger proportion of the study area could be used in ALS-based determination of SI when a time series was available.This was because areas that were unsuitable for SI determination between two points in time could be subject to SI determination based on data from another part of the time series.展开更多
Bemisia tabaci is a polyphagous herbivore that feeds on a wide range of horticultural and ornamental crops cultivated under diverse ecological zones. In Sierra Leone, B. tabaci is found to infest a wide range of veget...Bemisia tabaci is a polyphagous herbivore that feeds on a wide range of horticultural and ornamental crops cultivated under diverse ecological zones. In Sierra Leone, B. tabaci is found to infest a wide range of vegetable crops by directly feeding on phloem sap thereby inducing physiological disorders, and also serve as a vector to gemini viruses. Invariably the destructive feeding of B. tabaci affects the productivity and aesthetic values of vegetables and other horticultural crops and hence is considered a serious economic pest. A bioassay experiment was carried out by rearing B. tabaci populations on four vegetable crops under controlled laboratory conditions to determine its life table and demographic parameters. Results showed that the intrinsic rate of growth which measures the population size and growth pattern was highest for populations reared on tomato crops with the following values: rm 0.145 female female−1 day−1, the gross reproduction rate (Ro), and finite growth rate λ were highest for population reared on tomato, correspondingly the development period from egg-adult emergence was shortest with a value of 26 d. Conversely, the computed demographical parameters rm, λ and Ro for the population reared on sweet pepper were 0.106 female female−1 day−1 respectively, with a corresponding development period egg-adult emergence as 36d. The computed biological parameters for okra and garden egg varied with intermediary values between tomato and pepper host materials. The survivorship rates were quite significant for the smaller instars (Instars 1-III) with over 80% surviving to pre-pupa and pupa stage for the populations reared for all the test materials. High mortality was noticed for the pre-pupa and pupa stages as their survival rates were significantly low compared to the high survival rates of the smaller instars. Less than 50% of pupae failed to emerge to adults except for populations reared on tomato test materials where 52% emerged to adults. The study indicated tomato as the most suitable host among the four vegetable crops. Although life table and demographic parameters are invaluable information for forecasting pest populations and help in designing pest management efforts, further investigations such as the economic threshold and economic injury levels of B. tabaci population are requisite decision tools for sound pest management decisions of B. tabaci on these vegetable crops. The information obtained from this investigation would be quite relevant for extension service and pest management practitioners where mixed vegetable farming is a common practice.展开更多
Identification keys for terrestrial small mammals are often based on scientific details that require close examination of museum specimens.This paper builds on external morphological characteristics of the rodents rec...Identification keys for terrestrial small mammals are often based on scientific details that require close examination of museum specimens.This paper builds on external morphological characteristics of the rodents recorded through live trapping from 2011 to 2023 in Nyungwe National Park,a tropical rainforest in Rwanda,to formulate a taxonomic key suitable for both expert and non-expert researchers working in similar ecosystems across Africa.We reviewed the literature on taxonomic keys and field guide documents for small mammals to assess their practicality and identify gaps,with a special focus on their relevance to tropical regions and our study area.We then integrated our field records to harmonize this new development.We describe 23 rodent species,identified and confirmed using advanced taxonomic techniques,including DNA barcoding and voucher specimens.The study emphasizes that external features—particularly field photographs,body coloration(dorsal,ventral,and lateral views),and other distinctive anatomical traits—can serve as an effective field taxonomic key for rodents and other terrestrial small mammals,accessible to a broad scientific community.The paper also discusses the limitations of traditional dichotomous keys compared to short descriptions paired with photographic illustrations.The resulting key can be used as a template and is open to refinement as additional species are confirmed,re-assessed,or validated through advanced tools.Future studies may adapt this approach for other terrestrial small mammals and different locations across African tropical rainforests.展开更多
A key property of the boreal forest is that it stores huge amounts of carbon(C),especially belowground in the soil.Amounts of C stored in the uppermost organic layer of boreal forest soils vary greatly in space due to...A key property of the boreal forest is that it stores huge amounts of carbon(C),especially belowground in the soil.Amounts of C stored in the uppermost organic layer of boreal forest soils vary greatly in space due to an interplay between several variables facilitating or preventing C accumulation.In this study,we split C stocks into the organic layer and charcoal C due to their difference in origin,stability,and ecological properties.We compared organic layer C and charcoal C stocks in two regions of south-central Norway(Trillemarka and Varaldskogen),characterized by Scots pine and Norway spruce forests with varying fire histories.We used structural equation modeling to investigate how vegetation composition,hydrotopography,and soil properties interplay to shape organic layer C and charcoal C stocks.Pine forests consistently contained larger organic layer C stocks than spruce forests.Charcoal stocks,in contrast,were less consistent across both forest types and study regions as pine forests had higher charcoal C stocks than spruce forests in Trillemarka,while the two forest types contained equal charcoal C stocks in Varaldskogen.Charcoal and soil organic layer C stocks increased with higher fire frequencies(number of fire events over the last 600 years),but not with a shorter time since last fire(TSF).Additionally,vegetation composition,terrain slope,and soil moisture were the most important drivers of the organic layer C stocks,while charcoal C stocks were mainly controlled by the depth of the organic layer.Also,microtopography was of importance for organic layer C and charcoal C,since depressions in the forest floor had more charcoal C than well-drained minor hills.展开更多
Herbivorous ungulates are vital elements of forest ecosystems,yet their impact on tree regeneration and forest dynamics is challenging to assess.Despite their significant influence,few studies measure browsing pressur...Herbivorous ungulates are vital elements of forest ecosystems,yet their impact on tree regeneration and forest dynamics is challenging to assess.Despite their significant influence,few studies measure browsing pressure independently of precise ungulate population data.This study aimed to determine the regeneration mechanisms of palatable tree species in natural forest ecosystems by measuring the forage abundance from young trees of focal species and estimating the browsing pressure exerted by ungulates.We analyzed an extensive dataset of 2,838 tree saplings in two national parks in Poland to examine relationships between variables using a zero-intercept linear regression,and multiple linear regression models,and performed parametric and nonparametric tests.We found that the browsing intensity index(BI)is a good predictor of browsing pressure.Both total abundance and twig dry mass loss due to ungulate browsing were more pronounced in shorter saplings,with these effects decreasing as sapling height increased.Picea abies was the most abundant browse source in the Tatra National Park(TNP),whereas Fagus sylvatica dominated in the Roztocze National Park(RNP).Acer pseudoplatanus and Sorbus aucuparia experienced significantly higher browsing pressure in the TNP,whereas Carpinus betulus was more heavily browsed than other species in the RNP.The increase in browse abundance rapidly reduced ungulate browsing pressure on highly palatable tree species.We conclude that despite the high browsing pressure on the palatable species,the contribution of browse from focal species helps to mitigate this pressure and supports their regeneration in the forest canopy.Therefore,this finding provides valuable insights for managing and conserving tree species vulnerable to ungulate browsing in natural forest ecosystems.In addition,the method we used in this study is novel to estimate browsing pressure and assess the recruitment potential of vulnerable tree species;hence,it can be applied in large-scale studies with similar scenarios.展开更多
The intertwined challenges of climate change, resource scarcity, and conflict require innovative integrated solutions that address both environmental and societal vulnerabilities. Technological innovation offers a tra...The intertwined challenges of climate change, resource scarcity, and conflict require innovative integrated solutions that address both environmental and societal vulnerabilities. Technological innovation offers a transformative pathway for climate change adaptation and peacebuilding, with emphasis on a holistic approach to managing resource conflicts and environmental challenges. This paper explores the synergies between emerging technologies and strategic framework to mitigate climate-induced tensions and foster resilience. It focuses on the application of renewable energy systems to reduce dependence on contested resources, blockchain technology to ensure transparency in climate finance, equitable resource allocation and Artificial Intelligence (AI) to enhance early warning systems for climate-related disaster and conflicts. Additionally, technologies such as precision agriculture and remote sensing empower communities to optimize resource use, adapt to shifting environmental conditions, and reduce competition over scares resources. These innovations with inclusive governance and local capacity-building are very primordial. Ultimately, the convergence of technology, policy, and local participation offers a scalable and replicable model for addressing the dual challenges of environmental degradation and instability, thereby paving the way for a more sustainable and peaceful future.展开更多
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.
基金This research was financially supported by the CAS consultation project(Grant number-2019-ZW11-Z-035)the National Basic Research Program of China(973)(Projects:2006CB202300,2011CB201100)+1 种基金China High-Tech R&D(863)Program Project(2013AA092600)We would like to thank Gao Deli,Academician of Chinese Academy of Sciences,for his comments and recommendation in publishing this paper in Petroleum Science.
文摘Natural gas hydrate(NGH)has been widely considered as an alternative to conventional oil and gas resources in the future energy resource supply since Trofimuk’s first resource assessment in 1973.At least 29 global estimates have been published from various studies so far,among which 24 estimates are greater than the total conventional gas resources.If drawn in chronological order,the 29 historical resource estimates show a clear downward trend,reflecting the changes in our perception with respect to its resource potential with increasing our knowledge on the NGH with time.A time series of the 29 estimates was used to establish a statistical model for predict the future trend.The model produces an expected resource value of 41.46×1012 m3 at the year of 2050.The statistical trend projected future gas hydrate resource is only about 10%of total natural gas resource in conventional reservoir,consistent with estimates of global technically recoverable resources(TRR)in gas hydrate from Monte Carlo technique based on volumetric and material balance approaches.Considering the technical challenges and high cost in commercial production and the lack of competitive advantages compared with rapid growing unconventional and renewable resources,only those on the very top of the gas hydrate resource pyramid will be added to future energy supply.It is unlikely that the NGH will be the major energy source in the future.
基金supported by the Shanxi Province Basic Research Program(No.20210302123374)Yuncheng University Doctoral Research Initiation Fund(No.YQ-2021008)+3 种基金Excellent doctors come to Shanxi to reward scientific research projects(No.QZX-2023020)Open Fund of State Key Laboratory of Precision Geodesy(No.SKLPG2025-1-1)Joint Open Fund of the Research Platforms of School of Computer Science,China University of Geosciences,Wuhan(No.PTLH2024-B-03)Hubei Provincial Natural Science Foundation Project(No.2025AFC095).
文摘The Yuncheng Basin,located in the southern part of the Fenwei Rift,North China,exhibits obvious crust thinning(Moho uplift of 6-8 km)and shallow Curie point depth(less than 18 km)and hence holds great potential for geothermal resources.However,geothermal exploration within the Yuncheng Basin typically faces significant challenges due to civil and industrial noise from dense populations and industrial activities.To address these challenges,both Controlled-Source Audio-frequency Magnetotellurics(CSAMT)and radon measurements were employed in Baozigou village to investigate the geothermal structures and identify potential geothermal targets.The CSAMT method effectively delineated the structure of the subsurface hydrothermal system,identifying the reservoir as Paleogene sandstones and Ordovician and Cambrian limestones at elevations ranging from−800 m to−2500 m.In particular,two concealed normal faults(F_(a)and F_(b))were newly revealed by the combination of CSAMT and radon profiling;these previously undetected faults,which exhibit different scales and opposing dips,are likely to be responsible for controlling the convection of thermal water within the Basin’s subsurface hydrothermal system.Moreover,this study developed a preliminary conceptual geothermal model for the Fen River Depression within the Yuncheng Basin,which encompasses geothermal heat sources,cap rocks,reservoirs,and fluid pathways,providing valuable insights for future geothermal exploration.In conjunction with the 3D geological model constructed from CSAMT resistivity structures beneath Baozigou village,test drilling is recommended in the northwestern region of the Baozigou area to intersect the potentially deep fractured carbonates that may contain temperature-elevated geothermal water.This study establishes a good set of guidelines for future geothermal exploration in this region,indicating that high-permeability faults in the central segments of the Fen River Depression are promising targets.
文摘Soil salinization may negatively affect microbial processes related to carbon dioxide （CO2） and nitrous oxide （N20） emissions. A short-term laboratory incubation experiment was conducted to investigate the effects of soil electrical conductivity （EC） and moisture content on CO2 and N20 emissions from sulfate-based natural saline soils. Three separate 100-m long transects were established along the salinity gradient on a salt-affected agricultural field at Mooreton, North Dakota, USA. Surface soils were collected from four equally spaced sampling positions within each transect, at the depths of 0-15 and 15-30 cm. In the laboratory, artificial soil cores were formed combining soils from both the depths in each transect, and incubated at 60% and 90% water-filled pore space （WFPS） at 25 ~C. The measured depth-weighted EC of the saturated paste extract （ECe） across the sampling positions ranged from 0.43 to 4.65 dS m-1. Potential nitrogen （N） mineralization rate and CO2 emissions decreased with increasing soil ECe, but the relative decline in soil CO2 emissions with increasing ECe was smaller at 60% WFPS than at 90% WFPS. At 60% WFPS, soil N20 emissions decreased from 133 g N20-N kg-1 soil at ECe （ 0.50 dS m-1 to 72 μg N20-N kg-1 soil at ECe = 4.65 dS m-1. In contrast, at 90% WFPS, soil N20 emissions increased from 262 g N20-N kg-1 soil at ECe ： 0.81 dS m-1 to 849 g N20-N kg-1 soil at ECe ： 4.65 dS m-1, suggesting that N20 emissions were linked to both soil ECe and moisture content. Therefore, spatial variability in soil ECe and pattern of rainfall over the season need to be considered when up-scaling N20 and CO2 emissions from field to landscape scales.
基金National Natural Science Foundation of China,No.42171093Scientific and Innovative Action Plan of Shanghai,No.21ZR1408500+2 种基金Shanghai Pujiang Program,No.21PJ1401600Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration,No.SHUES2021A02China Scholarship Council。
文摘Urbanization has caused significant landscape changes in rural areas,leading to the emergence of urbanized landscapes(ULs),which have been generally criticized by authorities and professionals.However,perceptions of ULs among local residents have rarely been studied.In this study,we chose five typical categories of ULs from rapidly transforming villages in Fujian Province,China–hardened water bank(HWB),big pavilion(BPA),big memorial arch(BMA),big ornamental lawn(BOL),and big square(BSQ)to do the study.We identified how these ULs were rated and ranked by on-site surveys,as well as how related aesthetic and multifunctional landscape characters(LCs)played a role.The results(N=550)showed that 1)residents supported the construction of ULs,and the most preferred category was that with the most natural elements(BOL)that was simultaneously well maintained.2)For the residents,the longer they had resided in the village and the fewer connections they had with the city,the more in favor they were of the ULs,and the more eager they were for landscape change.In addition,residents with higher education and Communist Party of China membership valued the naturalness related LCs more highly.3)Two contradictory preference features,naturalness and livability,should be well coordinated and balanced to construct an improved favorable village for the residents,to realize a balanced and sustainable development path.This study makes great theoretical contributions to landscape research and provides new insights into rural planning and construction.
文摘Cassava-groundnut intercropping is not a common practice among smallholder farmers in Sierra Leone even though both crops are well suited for intercropping. On-farm trials were conducted in three locations (Bai Largor, Bassah, and Njala Kanima) in the Moyamba district during the 2021 cropping season to investigate the efficacy of cassava-groundnut intercropping for increasing crop productivity and soil organic carbon stock on smallholder farms in the Moyamba district, Southern Sierra Leone. The experimental design was a randomized complete block design in three replications with treatments of sole groundnut, sole cassava and cassava-groundnut intercropping. Data on the yield and yield components of cassava and groundnut were analysed using the PROC MIXED procedure of SAS 9.4 and means were compared using the standard error of difference (SED). The above-ground biomass, number of roots per plant, and fresh root yield of cassava were not significantly (p > 0.05) affected by the cassava-based cropping system. Averaged across locations, intercropping cassava with groundnut decreased the above-ground biomass, the number of roots per plant, and fresh root yield of cassava by 17%, 11%, and 17%, respectively. The above-ground biomass, number of pods per plant and fresh pod yield of groundnut were significantly (p 1), the highest net revenue and benefit-cost ratio. The benefit-cost ratio was also favourable for the sole cassava (BCR > 1) but not favourable for the sole groundnut (BCR < 1). Averaged across locations, intercropping cassava with groundnut increased the benefit-cost ratio by 121% and 13% when compared to the sole groundnut and sole cassava. In the event of a 40% yield loss for the cassava and groundnut, the benefit-cost ratio was favourable (1.12) only for the cassava groundnut intercropping system. The net soil organic carbon stock was favourable only for the cassava-groundnut intercrop. Averaged across locations, the net soil organic carbon for the cassava-groundnut intercropping increased by 3.4% when compared to the baseline within one cropping cycle of the cassava (12 months). The results confirm that cassava-groundnut intercropping is a sustainable land management practice that could enhance crop productivity and soil organic carbon stock on smallholder farms.
基金funding under the umbrella of ERA-NET Cofund ForestValue project NOBEL,“Novel business models and mechanisms for the sustainable supply of and payment for forest ecosystem services”ForestValue was funded by the European Union's Horizon 2020 research and innovation program(grant number 773324)+1 种基金Furthermore,the Norwegian Environment Agency funded the collection of the additional plots as a part of the project“Remote sensing-based mapping and monitoring of the forest ecosystem”(grant number 18087221)supported by the Norwegian Research Council(project number 297883).
文摘Centuries of forest exploitation have caused significant loss of natural forests in Europe,leading to a decline in populations for many species.To prevent further loss in biodiversity,the Norwegian government has set a target of protecting 10%of the forested area.However,recent data from the National Forest Inventory(NFI)reveals that less than 2%of Norway's forested area consists of natural forests.To identify forests with high conservation value,we used vertical and horizontal variables derived from airborne laser scanning(ALS)data,along with NFI plot measurements.Our study aimed to predict the presence of natural forests across three counties in southeastern Norway,using three different definitions:pristine,near-natural,and semi-natural forests.Natural forests are scarce,and their underrepresentation in field reference data can compromise the accuracy of the predictions.To address this,we assessed the potential gain of including additional field data specifically targeting natural forests to achieve a better balance in the dataset.Additionally,we examined the impact of stratifying the data by dominant tree species on the performance of the models.Our results revealed that semi-natural forests were the most accurately predicted,followed by near-natural and pristine forests,with Matthews correlation coefficient values of 0.32,0.24,and 0.17,respectively.Including additional field data did not improve the predictions.However,stratification by species improved the accuracy of predictions for near-natural and semi-natural forests,while reducing accuracy for pristine forests.The use of horizontal variables did not improve the predictions.Our study demonstrates the potential of ALS data in identifying forests with high conservation value.It provides a basis for further research on the use of ALS data for the detection and conservation of natural forests,offering valuable insights to guide future forest preservation efforts.
文摘This research was carried out to evaluate the preference and adoption of harvesting, uprooting, stump burning, pruning and thinning practices for controlling the spread ofProsopisjuliflora （prosopis） within Marigat Division of the Baringo District, Kenya. A survey methodology was employed using a random sample of 25 Farmer Field School （FFS） members and 5 non=FFS members from each of the five locations of Marigat Division. In total, 100 FFS members and 25 non-FFS members participated in the study; addi- tional supplementary data were collected from the Kenya Forestry Research Institute （KEFRI）, a major facilitator and trainer of the identified FFS activities and practices in the study area since 2004. More than 80% of the local community never undertook any form of prosopis management practice; however, this changed after FFS training, indicating an acquisition and retention of knowledge which probably diffused to the non-FFS counterparts, through either formal or informal ways. Harvesting was the most preferred （100%） and stump burning the least preferred （46%） practice of managing the spread of prosopis. The success and preference of any prosopis management practice was attributed to wood and non-wood benefits derived from prosopis and growing of animal fodder and food crops on rehabilitated land. More than 80% of respondents attributed ineffectiveness of any prosopis management practice to coppicing and viable seed banks of the tree, while 50% highlighted a lack of consistency and integration in carrying out manage- ment practices. The reported negative attitude towards prosopis changed after training with none of the view to eradicate it. Labor intensity and frequent regeneration of seedlings were identified as the major challenges faced during the implementation of proso- pis management practices. In conclusion, the study shows that harvesting, uprooting, stump burning, pruning and thinning realized through consistent holistic integration contribute to containing the spread of prosopis trees in Baringo, Kenya.
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.
基金Open access funding provided by Norwegian University of Life Sciences。
文摘Forest degradation induced by intensive forest management and temperature increase by climate change are resulting in biodiversity decline in boreal forests.Intensive forest management and high-end climate emission scenarios can further reduce the amount and diversity of deadwood,the limiting factor for habitats for saproxylic species in European boreal forests.The magnitude of their combined effects and how changes in forest management can affect deadwood diversity under a range of climate change scenarios are poorly understood.We used forest growth simulations to evaluate how forest management and climate change will individually and jointly affect habitats of red-listed saproxylic species in Finland.We simulated seven forest management regimes and three climate scenarios(reference,RCP4.5 and RCP8.5)over 100 years.Management regimes included set aside,continuous cover forestry,business-as-usual(BAU)and four modifications of BAU.Habitat suitability was assessed using a speciesspecific habitat suitability index,including 21 fungal and invertebrate species groups.“Winner”and“loser”species were identified based on the modelled impacts of forest management and climate change on their habitat suitability.We found that forest management had a major impact on habitat suitability of saproxylic species compared to climate change.Habitat suitability index varied by over 250%among management regimes,while overall change in habitat suitability index caused by climate change was on average only 2%.More species groups were identified as winners than losers from impacts of climate change(52%–95%were winners,depending on the climate change scenario and management regime).The largest increase in habitat suitability index was achieved under set aside(254%)and the climate scenario RCP8.5(>2%),while continuous cover forestry was the most suitable regime to increase habitat suitability of saproxylic species(up to+11%)across all climate change scenarios.Our results show that close-to-nature management regimes(e.g.,continuous cover forestry and set aside)can increase the habitat suitability of many saproxylic boreal species more than the basic business-as-usual regime.This suggests that biodiversity loss of many saproxylic species in boreal forests can be mitigated through improved forest management practices,even as climate change progresses.
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.
文摘Human well-being and livelihoods depend on natural ecosystem services(ESs).Following the increment of population,ESs have been deteriorated over time.Ultimately,land use/land cover(LULC)changes have a profound impact on the change of ecosystem.The primary goal of this study is to determine the impacts of LULC changes on ecosystem service values(ESVs)in the upper Gilgel Abbay watershed,Ethiopia.Changes in LULC types were studied using three Landsat images representing 1986,2003,and 2021.The Landsat images were classified using a supervised image classification technique in Earth Resources Data Analysis System(ERDAS)Imagine 2014.We classified ESs in this study into four categories(including provisioning,regulating,supporting,and cultural services)based on global ES classification scheme.The adjusted ESV coefficient benefit approach was employed to measure the impacts of LULC changes on ESVs.Five LULC types were identified in this study,including cultivated land,forest,shrubland,grassland,and water body.The result revealed that the area of cultivated land accounted for 64.50%,71.50%,and 61.50%of the total area in 1986,2003,and 2021,respectively.The percentage of the total area covered by forest was 9.50%,5.90%,and 14.80%in 1986,2003,and 2021,respectively.Result revealed that the total ESV decreased from 7.42×10^(7) to 6.44×10^(7) USD between 1986 and 2003.This is due to the expansion of cultivated land at the expense of forest and shrubland.However,the total ESV increased from 6.44×10^(7) to 7.76×10^(7) USD during 2003-2021,because of the increment of forest and shrubland.The expansion of cultivated land and the reductions of forest and shrubland reduced most individual ESs during 1986-2003.Nevertheless,the increase in forest and shrubland at the expense of cultivated land enhanced many ESs during 2003-2021.Therefore,the findings suggest that appropriate land use practices should be scaled-up to sustainably maintain ESs.
文摘Climate change impacts soil nitrogen, influencing plant responses to elevated atmospheric [CO2]. Understanding the interaction between nitrogen supply and elevated [CO2] is crucial for predicting plant future performance. This study examined the interactive effects of elevated [CO2] and nitrogen supply on the eco-physiological performance of yellow birch. Seedlings were exposed to two [CO2] levels and five nitrogen supply levels for 4 months. Growth parameters such as seedling height and root collar diameter increased with higher nitrogen supply and elevated [CO2], while specific leaf area decreased. [CO2] elevation and increasing nitrogen supply also increased the total and stem, and leaf biomass. The elevated [CO2] increased the stem mass ratio but decreased the root-to-shoot ratio and root mass ratio. However, decreases in nitrogen supply increased root mass ratio and root-to-shoot ratio. The elevated [CO2] increased the maximum rate of Rubisco carboxylation (Vcmax) and photosynthetic electron transport (Jmax), but the effect on Jmax was statistically significant only at the two highest nitrogen supply levels. The results indicate that yellow birch may increase photosynthetic capacity, biomass, and growth in the future when [CO2] is higher.
基金part of the Centre for Research-based Innovation SmartForest:Bringing Industry 4.0 to the Norwegian forest sector(NFR SFI project no.309671,smartforest.no)。
文摘Site index(SI)is determined from the top height development and is a proxy for forest productivity,defined as the expected top height for a given species at a certain index age.In Norway,an index age of 40 years is used.By using bi-temporal airborne laser scanning(ALS)data,SI can be determined using models estimated from SI observed on field plots(the direct approach)or from predicted top heights at two points in time(the height differential approach).Time series of ALS data may enhance SI determination compared to conventional methods used in operational forest inventory by providing more detailed information about the top height development.We used longitudinal data comprising spatially consistent field and ALS data collected from training plots in 1999,2010,and 2022 to determine SI using the direct and height differential approaches using all combinations of years and performed an external validation.We also evaluated the use of data assimilation.Values of root mean square error obtained from external validation were in the ranges of 16.3%–21.4%and 12.8%–20.6%of the mean fieldregistered SI for the direct approach and the height differential approach,respectively.There were no statistically significant effects of time series length or the number of points in time on the obtained accuracies.Data assimilation did not result in any substantial improvement in the obtained accuracies.Although a time series of ALS data did not yield greater accuracies compared to using only two points in time,a larger proportion of the study area could be used in ALS-based determination of SI when a time series was available.This was because areas that were unsuitable for SI determination between two points in time could be subject to SI determination based on data from another part of the time series.
文摘Bemisia tabaci is a polyphagous herbivore that feeds on a wide range of horticultural and ornamental crops cultivated under diverse ecological zones. In Sierra Leone, B. tabaci is found to infest a wide range of vegetable crops by directly feeding on phloem sap thereby inducing physiological disorders, and also serve as a vector to gemini viruses. Invariably the destructive feeding of B. tabaci affects the productivity and aesthetic values of vegetables and other horticultural crops and hence is considered a serious economic pest. A bioassay experiment was carried out by rearing B. tabaci populations on four vegetable crops under controlled laboratory conditions to determine its life table and demographic parameters. Results showed that the intrinsic rate of growth which measures the population size and growth pattern was highest for populations reared on tomato crops with the following values: rm 0.145 female female−1 day−1, the gross reproduction rate (Ro), and finite growth rate λ were highest for population reared on tomato, correspondingly the development period from egg-adult emergence was shortest with a value of 26 d. Conversely, the computed demographical parameters rm, λ and Ro for the population reared on sweet pepper were 0.106 female female−1 day−1 respectively, with a corresponding development period egg-adult emergence as 36d. The computed biological parameters for okra and garden egg varied with intermediary values between tomato and pepper host materials. The survivorship rates were quite significant for the smaller instars (Instars 1-III) with over 80% surviving to pre-pupa and pupa stage for the populations reared for all the test materials. High mortality was noticed for the pre-pupa and pupa stages as their survival rates were significantly low compared to the high survival rates of the smaller instars. Less than 50% of pupae failed to emerge to adults except for populations reared on tomato test materials where 52% emerged to adults. The study indicated tomato as the most suitable host among the four vegetable crops. Although life table and demographic parameters are invaluable information for forecasting pest populations and help in designing pest management efforts, further investigations such as the economic threshold and economic injury levels of B. tabaci population are requisite decision tools for sound pest management decisions of B. tabaci on these vegetable crops. The information obtained from this investigation would be quite relevant for extension service and pest management practitioners where mixed vegetable farming is a common practice.
文摘Identification keys for terrestrial small mammals are often based on scientific details that require close examination of museum specimens.This paper builds on external morphological characteristics of the rodents recorded through live trapping from 2011 to 2023 in Nyungwe National Park,a tropical rainforest in Rwanda,to formulate a taxonomic key suitable for both expert and non-expert researchers working in similar ecosystems across Africa.We reviewed the literature on taxonomic keys and field guide documents for small mammals to assess their practicality and identify gaps,with a special focus on their relevance to tropical regions and our study area.We then integrated our field records to harmonize this new development.We describe 23 rodent species,identified and confirmed using advanced taxonomic techniques,including DNA barcoding and voucher specimens.The study emphasizes that external features—particularly field photographs,body coloration(dorsal,ventral,and lateral views),and other distinctive anatomical traits—can serve as an effective field taxonomic key for rodents and other terrestrial small mammals,accessible to a broad scientific community.The paper also discusses the limitations of traditional dichotomous keys compared to short descriptions paired with photographic illustrations.The resulting key can be used as a template and is open to refinement as additional species are confirmed,re-assessed,or validated through advanced tools.Future studies may adapt this approach for other terrestrial small mammals and different locations across African tropical rainforests.
基金funded by the Norwegian University of Life Sciences(NMBU)a strategic institutional research program at the Norwegian Institute of Bioeconomy Research(NIBIO).
文摘A key property of the boreal forest is that it stores huge amounts of carbon(C),especially belowground in the soil.Amounts of C stored in the uppermost organic layer of boreal forest soils vary greatly in space due to an interplay between several variables facilitating or preventing C accumulation.In this study,we split C stocks into the organic layer and charcoal C due to their difference in origin,stability,and ecological properties.We compared organic layer C and charcoal C stocks in two regions of south-central Norway(Trillemarka and Varaldskogen),characterized by Scots pine and Norway spruce forests with varying fire histories.We used structural equation modeling to investigate how vegetation composition,hydrotopography,and soil properties interplay to shape organic layer C and charcoal C stocks.Pine forests consistently contained larger organic layer C stocks than spruce forests.Charcoal stocks,in contrast,were less consistent across both forest types and study regions as pine forests had higher charcoal C stocks than spruce forests in Trillemarka,while the two forest types contained equal charcoal C stocks in Varaldskogen.Charcoal and soil organic layer C stocks increased with higher fire frequencies(number of fire events over the last 600 years),but not with a shorter time since last fire(TSF).Additionally,vegetation composition,terrain slope,and soil moisture were the most important drivers of the organic layer C stocks,while charcoal C stocks were mainly controlled by the depth of the organic layer.Also,microtopography was of importance for organic layer C and charcoal C,since depressions in the forest floor had more charcoal C than well-drained minor hills.
基金funded by Polish National Science Foundation(NCN)(grant No.2018/31/B/NZ8/02786,project title:“How do largescale disturbances influence the relationship between ungulate herbivory and natural regeneration in temperate forests?”)from the Ministry of Science and Higher Education of the Republic of Poland within the framework of statutory activities SUB/040011-D019/2020 of the Department of Forest Biodiversity,University of Agriculture in Krakow.
文摘Herbivorous ungulates are vital elements of forest ecosystems,yet their impact on tree regeneration and forest dynamics is challenging to assess.Despite their significant influence,few studies measure browsing pressure independently of precise ungulate population data.This study aimed to determine the regeneration mechanisms of palatable tree species in natural forest ecosystems by measuring the forage abundance from young trees of focal species and estimating the browsing pressure exerted by ungulates.We analyzed an extensive dataset of 2,838 tree saplings in two national parks in Poland to examine relationships between variables using a zero-intercept linear regression,and multiple linear regression models,and performed parametric and nonparametric tests.We found that the browsing intensity index(BI)is a good predictor of browsing pressure.Both total abundance and twig dry mass loss due to ungulate browsing were more pronounced in shorter saplings,with these effects decreasing as sapling height increased.Picea abies was the most abundant browse source in the Tatra National Park(TNP),whereas Fagus sylvatica dominated in the Roztocze National Park(RNP).Acer pseudoplatanus and Sorbus aucuparia experienced significantly higher browsing pressure in the TNP,whereas Carpinus betulus was more heavily browsed than other species in the RNP.The increase in browse abundance rapidly reduced ungulate browsing pressure on highly palatable tree species.We conclude that despite the high browsing pressure on the palatable species,the contribution of browse from focal species helps to mitigate this pressure and supports their regeneration in the forest canopy.Therefore,this finding provides valuable insights for managing and conserving tree species vulnerable to ungulate browsing in natural forest ecosystems.In addition,the method we used in this study is novel to estimate browsing pressure and assess the recruitment potential of vulnerable tree species;hence,it can be applied in large-scale studies with similar scenarios.
文摘The intertwined challenges of climate change, resource scarcity, and conflict require innovative integrated solutions that address both environmental and societal vulnerabilities. Technological innovation offers a transformative pathway for climate change adaptation and peacebuilding, with emphasis on a holistic approach to managing resource conflicts and environmental challenges. This paper explores the synergies between emerging technologies and strategic framework to mitigate climate-induced tensions and foster resilience. It focuses on the application of renewable energy systems to reduce dependence on contested resources, blockchain technology to ensure transparency in climate finance, equitable resource allocation and Artificial Intelligence (AI) to enhance early warning systems for climate-related disaster and conflicts. Additionally, technologies such as precision agriculture and remote sensing empower communities to optimize resource use, adapt to shifting environmental conditions, and reduce competition over scares resources. These innovations with inclusive governance and local capacity-building are very primordial. Ultimately, the convergence of technology, policy, and local participation offers a scalable and replicable model for addressing the dual challenges of environmental degradation and instability, thereby paving the way for a more sustainable and peaceful future.
