In this paper, the problems of rational use, protection and management of water and irrigated land resources of Uzbekistan are discussed. Uzbekistan is using more than 50% water resources of the region and therefore i...In this paper, the problems of rational use, protection and management of water and irrigated land resources of Uzbekistan are discussed. Uzbekistan is using more than 50% water resources of the region and therefore it’s more vulnerable to the problems of water deficiency and pollution caused by mismanagement, use of outdated technologies, and climate change impact. Utilization of water resources on main branches of economy (irrigation, industry and drinking water supply) from 2000-2009 and in some cases beyond this period was analyzed. Based on the data analyzed, the conditions of irrigated land degradation in Uzbekistan are estimated. The results of this analysis suggest several possibilities toward a sustainable use of irrigated lands: i) reduction of the groundwater table depth;ii) decrease of the level of mineralization of groundwater, and iii) improvement of ameliorative conditions of irrigated lands. The causes resulting in degradation of the irrigated lands and practical measures on the reduction of salinization of the irrigated lands are also recommended.展开更多
In the western and central Pacific Ocean,upper strata waters exhibit highly dynamic oceanographic features under ENSO variability.This has been proved to be responsible for the dynamic change of both abundance and zon...In the western and central Pacific Ocean,upper strata waters exhibit highly dynamic oceanographic features under ENSO variability.This has been proved to be responsible for the dynamic change of both abundance and zonal distribution of skipjack tuna(Katsuwonus pelamis).Although causality has been suggested by researchers using physical-biological interaction models,cumulative evidence needs to be obtained and the tenability of assertion needs to be tested from an ecological habitat perspective,based on fisheries data.For purse seine fishery,the use of catch per unit effort(CPUE)as an indication of the abundance is confusing because of technical improvements over the whole exploitation history and unbalanced individual fishing characteristic of vessels.It is particularly interesting to discriminate between habitat characteristics in comparative scenarios of CPUE application.This study identified habitat traits based on a series of oceanographic factors from a global ocean reanalysis model.A comparison was conducted between two habitat models based on unprocessed purse seine CPUE and standardized CPUE considering fishing characteristics.The results suggest that standardized CPUE could model the regular zonal shift of habitat compatible with the observed fishing efforts transfer,and achieved better prediction capacity than unprocessed CPUE.Furthermore,the habitat of skipjack tuna was also characterized and linked with surface and subsurface thermal environment,ocean current,dissolved oxygen,biotic environment,and ENSO variability.The monthly-averaged habitat suitable index,derived from the optimal habitat model prediction,showed a significant linear relationship with the southern oscillation index,which suggested that El Ni?o episodes eventually provide more preferable habitat for skipjack tuna under ENSO variability.展开更多
The Central Asian lowlands are characterized by an arid and continental climate. At the same time, the large streams and rivers have been providing water for the development of flourishing oases and extensive irrigate...The Central Asian lowlands are characterized by an arid and continental climate. At the same time, the large streams and rivers have been providing water for the development of flourishing oases and extensive irrigated farming areas. Bukhara is one of those oases. The population of 1.7 mln. and especially the agricultural sector (with an irrigated area of 275,000 ha) use a considerable amount of water. But as the flat topography does not provide sufficient natural drainage, water logging and raising groundwater tables have become serious problems for the agricultural productivity. The combination of the high salinity of the irrigation water and the generous application of fertilizers leads to a widespread soil salinization. Excessive leaching is supposed to reduce the top soil salinity, but as the drainage system is only covering a small portion of the irrigated areas and is in need of maintenance, this process only contributes to the ongoing salinization and the reduction of soil fertility and crop yields. The data presented here for the years 2000 to 2013 indicate that the groundwater table is rising throughout the region while the groundwater salinity is decreasing. The soil salinity on the other hand is, after an improvement during the first half of the study period, slightly increasing since 2009, which also is reflected in the slight worsening of the condition of the reclaimed land during the same period.展开更多
The aim of our study was to assess the influence of motorways on landscape structure changes. The research was situated on segments of the D1 and D3 motorways in the Czech Republic. The method used for determining the...The aim of our study was to assess the influence of motorways on landscape structure changes. The research was situated on segments of the D1 and D3 motorways in the Czech Republic. The method used for determining the impacts of the construction and operation of the motorway on the landscape structure was based on comparing the development of the land cover types in an area where the motorway was present for almost the entire monitored period (D1 motorway segment) with the development of the land cover types in an area where the motorway was constructed towards the end of the monitored period (D3 motorway segment). Monitored period?was?between years 1949, 1988 (1984 segment of motorway D3) and 2007. Source materials were processed and analyzed in the ArcGIS software environment. Our comparison indicated that the main differences between segments were in the level of development of commercial, industrial and agricultural built-up area in the vicinity of motorways. The existence of the motorway also contributed to the development of residential areas. It should be noted that in both cases there was also an increase in the extension?of shrubs and scattered vegetation, and in small quantities also category of forest.展开更多
The paper discussed the influence of the forms of sediment accumulation on the surface of glaciers on their chemical and physicochemical properties.The materials sampled from the surface of five glaciers of the Svalba...The paper discussed the influence of the forms of sediment accumulation on the surface of glaciers on their chemical and physicochemical properties.The materials sampled from the surface of five glaciers of the Svalbard Archipelago was analyzed.We studied such forms of sediment accumulation as dirt cones-the ice core covered with sediments and cryoconite holes-hollows on the glacier surface containing cryoconite material.Parameters such as total organic carbon content,microbiological activity,pH,the content of mobile forms of potassium and phosphorus,and concentrations of heavy and trace metals were studied.Also,mesomorphological studies were carried out and the polydisperse composition of the sediments was determined.According to the results of this work,it was found that the content of organic carbon in the material selected from dirt cones and cryoconite holes can be up to 2.5%,but the content of clay particles in it is mainly at the 10–15%level.Potassium concentrations are up to 250 mg/kg,and phosphorus is up to 800 mg/kg.The content of metals is typical or lower than in the previously published data.The main influence on the chemical composition of materials has a geographical factor of the sampling site,rather than the form of material accumulation.展开更多
The Aydar Arnasay Lakes System (AALS) is an artificial lake system which was created in 1969 by diverting flood water from Chardarya reservoir. It has developed into a wetland of 4000 km2 area recognized by the Ramsar...The Aydar Arnasay Lakes System (AALS) is an artificial lake system which was created in 1969 by diverting flood water from Chardarya reservoir. It has developed into a wetland of 4000 km2 area recognized by the Ramsar Convention as of global importance. It is not only a refuge for birds and wildlife but also has seen the emergence of fishery and tourism since. Understanding of its behavior with respect to the quantitative and qualitative aspects of water resources is important for future use and management, especially for further development of fishery and ecotourism. The factors influencing changes in quantity and quality of ААLS water were studied between 1993 and 2011. Starting from 1993 the water level and water volume of the lake progressively increased. The spatio-temporal distributions of pH, dissolved oxygen, ammonium, nitrite, nitrate, phosphate, chloride, and biochemical oxygen demand (BOD5) during 2003-2005 and 2009-2011 were determined. On the basis of the conducted hydrological and hydro-chemical research fishery development in ААLS is recommended. The question is posed what requirements have to be in met in the future in order to guarantee the prolonged existence of the lake at a suitable water quality.展开更多
The arid zone rivers Amudarya and Syrdarya are located in Central Asia and are subjected to the influx of different kinds of natural and anthropogenic pollutants. The concentrations and speciation of heavy metals, nam...The arid zone rivers Amudarya and Syrdarya are located in Central Asia and are subjected to the influx of different kinds of natural and anthropogenic pollutants. The concentrations and speciation of heavy metals, namely, Hg, Cr, Cd, Co, U, Zn, Sc, Fe, Br, Au, and Sm. in the Amudarya and Syrdarya rivers water in the territory of Uzbekistan were investigated by applying the neutron-activation analysis and through experimental modeling using appropriate radionuclides. The heavy metals speciation in the rivers water was separated in cationic, anionic, and a combination of colloidal and neutral forms. The experimental results showed that heavy metals in the Amudarya and Syrdarya rivers water migrate as a complex set of suspended solids, cationic, anionic, and a combination of colloidal neutral forms. The ratio of neutral and colloidal forms averages approximately 40% for the majority of the investigated heavy metals, and the share of neutral and colloidal forms of heavy metals in the Syrdarya river water is slightly less than in the Amudarya river water (10-20%), which might be due to discharge of water from agricultural and industry sectors into the river.展开更多
The water budget of the examined wetland was extremely variable in the past six years. Principally, it was affected by the water regime of the River Danube and the climatic factors. In order to investigate the changes...The water budget of the examined wetland was extremely variable in the past six years. Principally, it was affected by the water regime of the River Danube and the climatic factors. In order to investigate the changes of these elements, and to succeed to forecast, statistical methods by using SPSS program were performed. The time series of the evaporation, of the precipitation and of the river's water-level were analysed by linear regression, by exponential smoothing, by deterministic models. In consequence of the river regulation, the low-water and the mean stage of Danube were decreasing during the last hundred years, because the riverbed was permanently deepening. Since the river has overflowed its bed and has inundated to the wide floodplain, the decrease of high-water did not appear. The decline of the flooded days signed the quicker passage of flood. These processes have prevented that the examined wetland is going to fill up from the floods. The difference in summer semester between the evaporation and the precipitation was increasing during the last fifty years. Therefore, the drying out of the wetland is going to be more frequent in the future. In the interests of the survival of this wetland, it is necessary to construct the restoring-system in the floodplain.展开更多
The Zarafshan river is a main trans-boundary river of the Aral Seabasin. As the main water resource, the Zarafshan river water is mainly used by the republics ofTajikistanandUzbekistan. We explored the trends of space...The Zarafshan river is a main trans-boundary river of the Aral Seabasin. As the main water resource, the Zarafshan river water is mainly used by the republics ofTajikistanandUzbekistan. We explored the trends of space-time pollution of river water with ammonium, nitrates, phosphates, biological oxygen demand (ВОD), fluorine and some heavy metals at seven water sampling points along theZarafshanRiver inUzbekistan. The experimental data showed that the water quality of the Zarafshanriver in 2002-2009 has undergone a considerable transformation, even by the length of the river. The chemical composition of the Zarafshan river water underwent changes due to the agricultural collector-drainage discharges and the sewage of the cities of Samarkand and Navoi. The water pollutants of the Zarafshan river, as a con- sequence of the agricultural pollution, consisted of mineralization, ammonium, nitrate, phosphate, and pesticides. Therefore, it is necessary to monitor the chemical composition of the large agricultural collector-drainage discharges into the river. The main sources of the heavy metals (primarily arsenic and zinc) in the Zarafshan river water were probably ore processing manufactures located interritoryofTajikistan.展开更多
Pelagic fish are the most abundant species in upwelling regions,contributing 25%of total global fisheries production.Climate-driven changes in the marine environment play a crucial role in their population dynamics.Us...Pelagic fish are the most abundant species in upwelling regions,contributing 25%of total global fisheries production.Climate-driven changes in the marine environment play a crucial role in their population dynamics.Using Chilean jack mackerel(Trachurus murphyi)as an example,this study conducted simulations to quantify the impacts of environmental variations on the stock assessment.A habitat-based surplus production model was developed by integrating suitable habitat area into the model parameters carrying capacity(K)and intrinsic growth rate(r),with a suitable habitat area serving as the proxy for the environmental conditions for Chilean jack mackerel in the Southeast Pacific Ocean.The dynamics of Chilean jack mackerel stock and fisheries data were simulated,and four assessment models with different configurations were built to fit simulated data,with or without considering environmental effects.The results indicated that Joint K-r model,which integrated both parameters with the suitable habitat area index,outperformed the others by coming closest to the‘true'population dynamics.Ignoring habitat variations in the estimation model tended to overestimate biomass and underestimate harvest rate and reference points.Without observation and process error,the results were estimated with bias,while FMSY is relatively sensitive.This research illustrates the importance to consider random errors and environmental influences on populations,and provides foundation guidelines for future stock assessment.展开更多
Direct sewage discharge may enhance soil nitrous oxide(N_(2)O)emissions,worsening the greenhouse effect.However,the effects of sewage discharge into bogs on N_(2)O flux,drivers and influencing mechanisms remain unclea...Direct sewage discharge may enhance soil nitrous oxide(N_(2)O)emissions,worsening the greenhouse effect.However,the effects of sewage discharge into bogs on N_(2)O flux,drivers and influencing mechanisms remain unclear.Additionally,investigating the impact of reclaimed water on N_(2)O flux is important for bog replenishment and water shortage alleviation.This study simulated sewage from different sources into a bog and analyzed N_(2)O fluxes,soil(organic carbon,total nitrogen,ammonium nitrogen,nitrate nitrogen,total phosphorus,available phosphorus,pH and electrical conductivity),plant(species richness and biomass)and microorganisms(ammonia-oxidizing archaea,napA,nirS,nirK and nosZ genes).Results showed that the reclaimed water did not significantly change N_(2)O flux,while 50%tap water mixed with 50%domestic sewage and domestic sewage significantly increased the N_(2)O flux.Among soil factors,available nitrogen and pH were key in influencing N_(2)O flux.Among plant parameters,species richness was the primary factor affecting N_(2)O flux.Nitrogen transformation functional genes contributed the most to the increase in the N_(2)O fluxes,with an increase in domestic sewage input leading to a higher abundance of these genes and subsequent N_(2)O emissions.Therefore,domestic sewage should be considered,as it significantly increases N_(2)O emissions by affecting the soil,plants and microorganisms,thereby increasing the global warming potential.This study’s findings suggest that using treated reclaimed water for bog replenishment could be an environmentally friendly approach to wetland management.展开更多
Relationship of soil and water is generally considered as important in soil science. To specify it further we studied two different soils in 2012-2013, three additional soils once and made several series of experiment...Relationship of soil and water is generally considered as important in soil science. To specify it further we studied two different soils in 2012-2013, three additional soils once and made several series of experiments with drying and wetting of the soils. Principal parameters studied were the gravimetric water content (GWC), water holding capacity (WHC), soil organic matter (SOM), their correlations and rates of change in drying or wetting. The three parameters are significantly inter-correlated. Distribution of GWC in the replicates of soils dried both in nature and in experiments was narrower than that in wet soils, while WHC changed less in drying. The correlations (GWC- WHC) became steeper (the slope coefficient higher) and the coefficient of determination (R2) lower. Attempts to increase WHC in wet soils with a high WHC even further were not successful. Drying may be fast or slow;rates of increase of WHC in wetting were all low, both in field and in the experiments, less than 0.1 g (H2O) g-1 (soil)·day-1. None of the three parameters can be considered as fixed characteristics of forest soils.展开更多
Globally,marine bioinvasions threaten marine ecosystem structure and function,with the Mediterranean Sea being one of the most affected regions.Such invasions are expected to increase due to climate change.We conducte...Globally,marine bioinvasions threaten marine ecosystem structure and function,with the Mediterranean Sea being one of the most affected regions.Such invasions are expected to increase due to climate change.We conducted a risk screening of marine organisms(37 fishes,38 invertebrates,and 9 plants),both extant and‘horizon’(i.e.,not present in the area but likely to enter it).Based on expert knowledge for the Eastern Adriatic Sea coasts of Slovenia,Croatia,and Montenegro,screenings were conducted under both current and predicted climate conditions indicating with an increase in sea surface temperature and salinity of the Adriatic Sea together with changes in precipitation regime.Our aims were to:(1)identify non-native extant and horizon marine species that may pose threats to native biodiversity and(2)evaluate the risk of invasiveness of the selected species under current and predicted climate conditions.Of the 84 species screened,there was an increase in those ranked as‘high risk’from 33(39.3%)under current climate conditions and to 47(56.0%)under global warming scenarios.For those ranked as‘very high’risk,the increase was from 6(7.1%)to 21(25.0%).Amongst the screened species,the already established high-risk species Pacific oyster Magallana gigas and Atlantic blue crab Callinectes sapidus represent a threat to ecosystem services.Given the under-representation of marine species in the current European Union List,the species we have ranked as high to very high risk should be included.展开更多
Greenhouse gas emissions from wetlands are significantly promoted by global nitrogen input for changing the rate of soil carbon and nitrogen cycling,and are substantially affected by soil labile carbon and nitrogen co...Greenhouse gas emissions from wetlands are significantly promoted by global nitrogen input for changing the rate of soil carbon and nitrogen cycling,and are substantially affected by soil labile carbon and nitrogen conversely.However,the driving mechanism by which soil labile carbon and nitrogen affect greenhouse gas emissions from wetland ecosystems under global nitrogen input is not well understood.Working out the driving factor of nitrogen input on greenhouse gas emissions from wetlands is critical to reducing global warming from nitrogen input.Thus,we synthesized 72 published studies(2144 paired observations)of greenhouse gas fluxes and soil labile compounds of carbon and nitrogen(ammonium,nitrate,dissolved organic carbon,soil microbial biomass nitrogen and carbon),to understand the effects of labile carbon and nitrogen on greenhouse gas emissions under global nitrogen input.Across the data set,nitrogen input significantly promoted carbon dioxide,methane and nitrous oxide emissions from wetlands.In particular,at lower nitrogen rates(<100 kg ha^(-1)$·yr^(-1))and with added ammonium compounds,freshwater wetland significantly promoted carbon dioxide and methane emissions.Peatland was the largest nitrous oxide source under these conditions.This meta-analysis also revealed that nitrogen input stimulated dissolved organic carbon,ammonium,nitrate,microbial biomass carbon and microbial biomass nitrogen accumulation in the wetland ecosystem.The variation-partitioning analysis and structural equation model were used to analyze the relationship between the greenhouse gas and labile carbon and nitrogen further.These results revealed that dissolved organic carbon(DOC)is the primary factor driving greenhouse gas emission from wetlands under global nitrogen input,whereas microbial biomass carbon(MBC)more directly affects greenhouse gas emission than other labile carbon and nitrogen.展开更多
There are increasing findings of the bivalve transmissible neoplasia derived from the Pacific mussel Mytilus trossulus(MtrBTN)in populations of different Mytilus species worldwide.The Subarctic is an area where this d...There are increasing findings of the bivalve transmissible neoplasia derived from the Pacific mussel Mytilus trossulus(MtrBTN)in populations of different Mytilus species worldwide.The Subarctic is an area where this disease has not yet been sought despite the fact that Mytilus spp.are widespread there,and M.trossulus itself is a boreal species.We used flow cytometry of the hemolymph,hemocytology,and histology to diagnose disseminated neoplasia in a sample of M.trossulus from Magadan in the subarctic Sea of Okhotsk.Neoplasia was identified in 11 of 214 mussels studied.Using mtDNA COI sequencing,we revealed genotypes identical or nearly identical to known MtrBTN ones in the hemolymph of most of the diseased mussels.Both MtrBTN evolutionary lineages have been identified,the widespread MtrBTN2,and MtrBTN1,so far only known from M.trossulus in British Columbia on the other side of the Pacific from Magadan.In addition,MtrBTN2 was represented by 2 common diverged mtDNA haplolineages.These conclusions were confirmed for selected cancerous mussels by molecular cloning of COI and additional nuclear and mtDNA genes.On the background of high genetic diversity,different cancers were similar in terms of ploidy(range 4.0–5.8 n)and nuclear-to-cell ratio.Our study provides the first description of neoplasia and MtrBTN in mussels from the Sea of Okhotsk and from the Subarctic,of both MtrBTN1 and MtrBTN2 in the same mussel population,and the first direct comparison between these transmissible cancers.展开更多
The high-elevation Tibetan Plateau(western China)is inhabited by a unique,though not particularly species-rich,community of organisms.We explored the species content and evolutionary history of the Tibetan Plateau end...The high-elevation Tibetan Plateau(western China)is inhabited by a unique,though not particularly species-rich,community of organisms.We explored the species content and evolutionary history of the Tibetan Plateau endemic freshwater snail genus Tibetoradix.Phylogenetic relationships within the genus were reconstructed based on available sequence data.We used a single-rate Poisson Tree Processes approach for species delimitation and compared putative species-level clades with already described taxa.We found that the genus consists of at least 6 species,of which we described 4 as new to science.Shell and soft body morphology was examined and the radula in Tibetoradix was described for thefirst time.Based on ourfindings,the diversification of the genus did not result in a prominent morphological differentiation and a number of species can be regarded as morphologically cryptic.Single species found in different drainage areas indicate relatively good passive dispersal abilities of the snails.The allopatric distribution of the species could result from competitive exclusion between them.The absence of Tibetoradix spp.outside the Tibetan Plateau could be explained by a scenario of an“evolutionary trap”,where adaptations to high elevation conditions prevented the taxa from a successful colonization of lower elevations.展开更多
The mutualistic symbiotic system formed by clumping arbuscular mycorrhizal fungi(AMF)and plants can remediate heavy metal-contaminated soils.However,the specific mechanisms underlying the interaction between AMF and i...The mutualistic symbiotic system formed by clumping arbuscular mycorrhizal fungi(AMF)and plants can remediate heavy metal-contaminated soils.However,the specific mechanisms underlying the interaction between AMF and inter-root microbial communities,particularly their impact on organic phosphorus(P)cycling,remain unclear.This study investigated the gene regulation processes involved in inter-root soil phosphorus cycling in wetland plants,specifically Iris tectorum,following inoculation with AMF under varying concentrations of chromium(Cr)stress.Through macro-genome sequencing,we analyzed the composition and structure of the inter-root soil microbial community associated with Iris tectorum under greenhouse pot conditions.The results demonstrated significant changes in the diversity and composition of the inter-root soil microbial community following AMF inoculation,with Proteobacteria,Actinobacteria,Chloroflexi,Acidobacteria,and Bacteroidetes being the dominant taxa.Under Cr stress,species and gene co-occurrence network analysis revealed that AMF promoted the transformation process of organic phosphorus mineralization and facilitated inorganic phosphorus uptake.Additionally,network analysis of functional genes indicated strong aggregation of(pstS,pstA,pstC,TC.PIT,phoR,pp-gppA)genes,which collectively enhanced phosphorus uptake by plants.These findings shed light on the inter-root soil phosphorus cycling process during the co-remediation of Cr-contaminated soil by AMF-Iris tectorum symbiosis,providing valuable theoretical support for the application of AMF-wetland plant symbiosis systems to remediate heavy metal-contaminated soil.展开更多
Various studies have established that feedstock choice,pyrolysis temperature,and pyrolysis type influence final biochar physicochemical characteristics.However,overarching analyses of pre-biochar creation choices and ...Various studies have established that feedstock choice,pyrolysis temperature,and pyrolysis type influence final biochar physicochemical characteristics.However,overarching analyses of pre-biochar creation choices and correlations to biochar characteristics are severely lacking.Thus,the objective of this work was to help researchers,biochar-stakeholders,and practitioners make more well-informed choices in terms of how these three major parameters influence the final biochar product.Utilizing approximately 5400 peer-reviewed journal articles and over 50,800 individual data points,herein we elucidate the selections that influence final biochar physical and chemical properties,total nutrient content,and perhaps more importantly tools one can use to predict biochar’s nutrient availability.Based on the large dataset collected,it appears that pyrolysis type(fast or slow)plays a minor role in biochar physico-(inorganic)chemical characteristics;few differences were evident between production styles.Pyrolysis temperature,however,affects biochar’s longevity,with pyrolysis temperatures>500℃ generally leading to longer-term(i.e.,>1000 years)half-lives.Greater pyrolysis temperatures also led to biochars containing greater overall C and specific surface area(SSA),which could promote soil physico-chemical improvements.However,based on the collected data,it appears that feedstock selection has the largest influence on biochar properties.Specific surface area is greatest in wood-based biochars,which in combination with pyrolysis temperature could likely promote greater changes in soil physical characteristics over other feedstock-based biochars.Crop-and other grass-based biochars appear to have cation exchange capacities greater than other biochars,which in combination with pyrolysis temperature could potentially lead to longer-term changes in soil nutrient retention.The collected data also suggest that one can reasonably predict the availability of various biochar nutrients(e.g.,N,P,K,Ca,Mg,Fe,and Cu)based on feedstock choice and total nutrient content.Results can be used to create designer biochars to help solve environmental issues and supply a variety of plant-available nutrients for crop growth.展开更多
Understanding the reproductive characteristics of a species is of crucial for accurate stock assessment and management plans to ensure sustainable fisheries.In this study,the size at 50%sexual maturity(L50)parameters ...Understanding the reproductive characteristics of a species is of crucial for accurate stock assessment and management plans to ensure sustainable fisheries.In this study,the size at 50%sexual maturity(L50)parameters in different bio-ecological provinces were estimated for bigeye tuna,Thunnus obesus,sampled from the Eastern Pacific Ocean tuna fisheries-dependent survey from 2013 to 2019.The overall sex ratio of the catch during the sampling differed significantly from 1:1.Bigeye tuna exhibit sexual dimorphism in the growth of males and females,with a clear shift in predominance from female to male with increasing sizes.In the North Pacific Sub-tropical Gyre(east)(NPST-east),North Pacific Tropical Gyre(NPTG),Pacific North Equatorial Countercurrent(PNEC),and Pacific Equatorial Divergence(PEQD),females(meals)reached sexual maturity round 102 cm(106 cm),106 cm(100 cm),125 cm(110 cm),and 113 cm(110 cm),respectively,the estimated L50 of bigeye tuna was 124.08 cm,121.97 cm,139.92 cm and 132.45 cm,respectively.The degree of populations mixing between equatorial(PNEC and PEQD)and high-latitude regions(NPST-east and NPTG)is extremely small,but it is reasonably high between the NPST-east and NPTG or PNEC and PEQD.These parameters were significantly different,suggesting the occurrence of a spatial difference in the size-at-maturity of bigeye tuna between these bio-ecological provinces.The findings of this study provide the key information for understanding the life history of bigeye tuna in the Eastern Pacific Ocean and will contribute to the conservation and sustainable yield of this species.展开更多
With the extirpation of apex predators from many North American systems, coyotes Canis latrans have become the de facto top predator and are ubiquitous members of most ecosystems. Keystone predators aid in maintaining...With the extirpation of apex predators from many North American systems, coyotes Canis latrans have become the de facto top predator and are ubiquitous members of most ecosystems. Keystone predators aid in maintaining ecosystem function by regulating the mammal community through direct predation and instilling the landscape of fear, yet the value of coyotes regulating systems to this capacity is understudied and likely variable across environments. Since coyotes are common in the Midwestern United States, we utilized camera traps and occupancy analyses to as- sess their role in regulating the distribution of mammalian herbivores in a fragmented suburban ecosystem. Forest cover was a strong positive predictor of white-tailed deer Odocoileus virginianus detection, while coyote occurrence had a negative effect. Coyotes exerted a negative effect on squirrel (Sciurus spp.) and eastern cottontail rabbit Sylvilagus floridanus occurrence, while urban cover was a positive predictor for the prey species' occurrence. These results suggest all 3 species behaviorally avoid coyotes whereby deer seek denser forest cover and squirrels and cottontails mitigate risk by increasing use of urban areas. Although previous studies reveal limited influence of coyote on the rest of the carnivore guild in suburban systems, we suggest coyotes play an important role in regulating the herbivorous mammals and hence may provide similar eco- logical, benefits in urban/suburban forest fragments through trophic cascades. Furthermore, since hunting may not be allowed in urban and suburban habitats, coyotes might also serve as the pri- mary regulator of nuisance species occurring at high abundance such as white-tailed deer and squirrels.展开更多
文摘In this paper, the problems of rational use, protection and management of water and irrigated land resources of Uzbekistan are discussed. Uzbekistan is using more than 50% water resources of the region and therefore it’s more vulnerable to the problems of water deficiency and pollution caused by mismanagement, use of outdated technologies, and climate change impact. Utilization of water resources on main branches of economy (irrigation, industry and drinking water supply) from 2000-2009 and in some cases beyond this period was analyzed. Based on the data analyzed, the conditions of irrigated land degradation in Uzbekistan are estimated. The results of this analysis suggest several possibilities toward a sustainable use of irrigated lands: i) reduction of the groundwater table depth;ii) decrease of the level of mineralization of groundwater, and iii) improvement of ameliorative conditions of irrigated lands. The causes resulting in degradation of the irrigated lands and practical measures on the reduction of salinization of the irrigated lands are also recommended.
基金The National Key R&D Program of China under contract Nos 2020YFD0901202 and 2019YFD0901502the National Natural Science Foundation of China under contract Nos 41806110,41506151 and 31902426。
文摘In the western and central Pacific Ocean,upper strata waters exhibit highly dynamic oceanographic features under ENSO variability.This has been proved to be responsible for the dynamic change of both abundance and zonal distribution of skipjack tuna(Katsuwonus pelamis).Although causality has been suggested by researchers using physical-biological interaction models,cumulative evidence needs to be obtained and the tenability of assertion needs to be tested from an ecological habitat perspective,based on fisheries data.For purse seine fishery,the use of catch per unit effort(CPUE)as an indication of the abundance is confusing because of technical improvements over the whole exploitation history and unbalanced individual fishing characteristic of vessels.It is particularly interesting to discriminate between habitat characteristics in comparative scenarios of CPUE application.This study identified habitat traits based on a series of oceanographic factors from a global ocean reanalysis model.A comparison was conducted between two habitat models based on unprocessed purse seine CPUE and standardized CPUE considering fishing characteristics.The results suggest that standardized CPUE could model the regular zonal shift of habitat compatible with the observed fishing efforts transfer,and achieved better prediction capacity than unprocessed CPUE.Furthermore,the habitat of skipjack tuna was also characterized and linked with surface and subsurface thermal environment,ocean current,dissolved oxygen,biotic environment,and ENSO variability.The monthly-averaged habitat suitable index,derived from the optimal habitat model prediction,showed a significant linear relationship with the southern oscillation index,which suggested that El Ni?o episodes eventually provide more preferable habitat for skipjack tuna under ENSO variability.
文摘The Central Asian lowlands are characterized by an arid and continental climate. At the same time, the large streams and rivers have been providing water for the development of flourishing oases and extensive irrigated farming areas. Bukhara is one of those oases. The population of 1.7 mln. and especially the agricultural sector (with an irrigated area of 275,000 ha) use a considerable amount of water. But as the flat topography does not provide sufficient natural drainage, water logging and raising groundwater tables have become serious problems for the agricultural productivity. The combination of the high salinity of the irrigation water and the generous application of fertilizers leads to a widespread soil salinization. Excessive leaching is supposed to reduce the top soil salinity, but as the drainage system is only covering a small portion of the irrigated areas and is in need of maintenance, this process only contributes to the ongoing salinization and the reduction of soil fertility and crop yields. The data presented here for the years 2000 to 2013 indicate that the groundwater table is rising throughout the region while the groundwater salinity is decreasing. The soil salinity on the other hand is, after an improvement during the first half of the study period, slightly increasing since 2009, which also is reflected in the slight worsening of the condition of the reclaimed land during the same period.
文摘The aim of our study was to assess the influence of motorways on landscape structure changes. The research was situated on segments of the D1 and D3 motorways in the Czech Republic. The method used for determining the impacts of the construction and operation of the motorway on the landscape structure was based on comparing the development of the land cover types in an area where the motorway was present for almost the entire monitored period (D1 motorway segment) with the development of the land cover types in an area where the motorway was constructed towards the end of the monitored period (D3 motorway segment). Monitored period?was?between years 1949, 1988 (1984 segment of motorway D3) and 2007. Source materials were processed and analyzed in the ArcGIS software environment. Our comparison indicated that the main differences between segments were in the level of development of commercial, industrial and agricultural built-up area in the vicinity of motorways. The existence of the motorway also contributed to the development of residential areas. It should be noted that in both cases there was also an increase in the extension?of shrubs and scattered vegetation, and in small quantities also category of forest.
基金supported by Russian Foundation for Basic Research(project No 19-05-50107)"The role of microparticles of organic carbon in degradation of ice cover of polar regions of the Earth and in the process of soil-like bodies formation".
文摘The paper discussed the influence of the forms of sediment accumulation on the surface of glaciers on their chemical and physicochemical properties.The materials sampled from the surface of five glaciers of the Svalbard Archipelago was analyzed.We studied such forms of sediment accumulation as dirt cones-the ice core covered with sediments and cryoconite holes-hollows on the glacier surface containing cryoconite material.Parameters such as total organic carbon content,microbiological activity,pH,the content of mobile forms of potassium and phosphorus,and concentrations of heavy and trace metals were studied.Also,mesomorphological studies were carried out and the polydisperse composition of the sediments was determined.According to the results of this work,it was found that the content of organic carbon in the material selected from dirt cones and cryoconite holes can be up to 2.5%,but the content of clay particles in it is mainly at the 10–15%level.Potassium concentrations are up to 250 mg/kg,and phosphorus is up to 800 mg/kg.The content of metals is typical or lower than in the previously published data.The main influence on the chemical composition of materials has a geographical factor of the sampling site,rather than the form of material accumulation.
文摘The Aydar Arnasay Lakes System (AALS) is an artificial lake system which was created in 1969 by diverting flood water from Chardarya reservoir. It has developed into a wetland of 4000 km2 area recognized by the Ramsar Convention as of global importance. It is not only a refuge for birds and wildlife but also has seen the emergence of fishery and tourism since. Understanding of its behavior with respect to the quantitative and qualitative aspects of water resources is important for future use and management, especially for further development of fishery and ecotourism. The factors influencing changes in quantity and quality of ААLS water were studied between 1993 and 2011. Starting from 1993 the water level and water volume of the lake progressively increased. The spatio-temporal distributions of pH, dissolved oxygen, ammonium, nitrite, nitrate, phosphate, chloride, and biochemical oxygen demand (BOD5) during 2003-2005 and 2009-2011 were determined. On the basis of the conducted hydrological and hydro-chemical research fishery development in ААLS is recommended. The question is posed what requirements have to be in met in the future in order to guarantee the prolonged existence of the lake at a suitable water quality.
文摘The arid zone rivers Amudarya and Syrdarya are located in Central Asia and are subjected to the influx of different kinds of natural and anthropogenic pollutants. The concentrations and speciation of heavy metals, namely, Hg, Cr, Cd, Co, U, Zn, Sc, Fe, Br, Au, and Sm. in the Amudarya and Syrdarya rivers water in the territory of Uzbekistan were investigated by applying the neutron-activation analysis and through experimental modeling using appropriate radionuclides. The heavy metals speciation in the rivers water was separated in cationic, anionic, and a combination of colloidal and neutral forms. The experimental results showed that heavy metals in the Amudarya and Syrdarya rivers water migrate as a complex set of suspended solids, cationic, anionic, and a combination of colloidal neutral forms. The ratio of neutral and colloidal forms averages approximately 40% for the majority of the investigated heavy metals, and the share of neutral and colloidal forms of heavy metals in the Syrdarya river water is slightly less than in the Amudarya river water (10-20%), which might be due to discharge of water from agricultural and industry sectors into the river.
文摘The water budget of the examined wetland was extremely variable in the past six years. Principally, it was affected by the water regime of the River Danube and the climatic factors. In order to investigate the changes of these elements, and to succeed to forecast, statistical methods by using SPSS program were performed. The time series of the evaporation, of the precipitation and of the river's water-level were analysed by linear regression, by exponential smoothing, by deterministic models. In consequence of the river regulation, the low-water and the mean stage of Danube were decreasing during the last hundred years, because the riverbed was permanently deepening. Since the river has overflowed its bed and has inundated to the wide floodplain, the decrease of high-water did not appear. The decline of the flooded days signed the quicker passage of flood. These processes have prevented that the examined wetland is going to fill up from the floods. The difference in summer semester between the evaporation and the precipitation was increasing during the last fifty years. Therefore, the drying out of the wetland is going to be more frequent in the future. In the interests of the survival of this wetland, it is necessary to construct the restoring-system in the floodplain.
文摘The Zarafshan river is a main trans-boundary river of the Aral Seabasin. As the main water resource, the Zarafshan river water is mainly used by the republics ofTajikistanandUzbekistan. We explored the trends of space-time pollution of river water with ammonium, nitrates, phosphates, biological oxygen demand (ВОD), fluorine and some heavy metals at seven water sampling points along theZarafshanRiver inUzbekistan. The experimental data showed that the water quality of the Zarafshanriver in 2002-2009 has undergone a considerable transformation, even by the length of the river. The chemical composition of the Zarafshan river water underwent changes due to the agricultural collector-drainage discharges and the sewage of the cities of Samarkand and Navoi. The water pollutants of the Zarafshan river, as a con- sequence of the agricultural pollution, consisted of mineralization, ammonium, nitrate, phosphate, and pesticides. Therefore, it is necessary to monitor the chemical composition of the large agricultural collector-drainage discharges into the river. The main sources of the heavy metals (primarily arsenic and zinc) in the Zarafshan river water were probably ore processing manufactures located interritoryofTajikistan.
基金supported by the National Key Research and Development Program of China(No.2019YFD0901404)。
文摘Pelagic fish are the most abundant species in upwelling regions,contributing 25%of total global fisheries production.Climate-driven changes in the marine environment play a crucial role in their population dynamics.Using Chilean jack mackerel(Trachurus murphyi)as an example,this study conducted simulations to quantify the impacts of environmental variations on the stock assessment.A habitat-based surplus production model was developed by integrating suitable habitat area into the model parameters carrying capacity(K)and intrinsic growth rate(r),with a suitable habitat area serving as the proxy for the environmental conditions for Chilean jack mackerel in the Southeast Pacific Ocean.The dynamics of Chilean jack mackerel stock and fisheries data were simulated,and four assessment models with different configurations were built to fit simulated data,with or without considering environmental effects.The results indicated that Joint K-r model,which integrated both parameters with the suitable habitat area index,outperformed the others by coming closest to the‘true'population dynamics.Ignoring habitat variations in the estimation model tended to overestimate biomass and underestimate harvest rate and reference points.Without observation and process error,the results were estimated with bias,while FMSY is relatively sensitive.This research illustrates the importance to consider random errors and environmental influences on populations,and provides foundation guidelines for future stock assessment.
基金supported by the National Key R&D Program of China(2022YFF1300900)the National Natural Science Foundation of China(32271624)+1 种基金the Foundation of Jilin Scientifc and Technological Development Project(20220203003SF)the Education Department of Jilin Province(JJKH20230516KJ).
文摘Direct sewage discharge may enhance soil nitrous oxide(N_(2)O)emissions,worsening the greenhouse effect.However,the effects of sewage discharge into bogs on N_(2)O flux,drivers and influencing mechanisms remain unclear.Additionally,investigating the impact of reclaimed water on N_(2)O flux is important for bog replenishment and water shortage alleviation.This study simulated sewage from different sources into a bog and analyzed N_(2)O fluxes,soil(organic carbon,total nitrogen,ammonium nitrogen,nitrate nitrogen,total phosphorus,available phosphorus,pH and electrical conductivity),plant(species richness and biomass)and microorganisms(ammonia-oxidizing archaea,napA,nirS,nirK and nosZ genes).Results showed that the reclaimed water did not significantly change N_(2)O flux,while 50%tap water mixed with 50%domestic sewage and domestic sewage significantly increased the N_(2)O flux.Among soil factors,available nitrogen and pH were key in influencing N_(2)O flux.Among plant parameters,species richness was the primary factor affecting N_(2)O flux.Nitrogen transformation functional genes contributed the most to the increase in the N_(2)O fluxes,with an increase in domestic sewage input leading to a higher abundance of these genes and subsequent N_(2)O emissions.Therefore,domestic sewage should be considered,as it significantly increases N_(2)O emissions by affecting the soil,plants and microorganisms,thereby increasing the global warming potential.This study’s findings suggest that using treated reclaimed water for bog replenishment could be an environmentally friendly approach to wetland management.
文摘Relationship of soil and water is generally considered as important in soil science. To specify it further we studied two different soils in 2012-2013, three additional soils once and made several series of experiments with drying and wetting of the soils. Principal parameters studied were the gravimetric water content (GWC), water holding capacity (WHC), soil organic matter (SOM), their correlations and rates of change in drying or wetting. The three parameters are significantly inter-correlated. Distribution of GWC in the replicates of soils dried both in nature and in experiments was narrower than that in wet soils, while WHC changed less in drying. The correlations (GWC- WHC) became steeper (the slope coefficient higher) and the coefficient of determination (R2) lower. Attempts to increase WHC in wet soils with a high WHC even further were not successful. Drying may be fast or slow;rates of increase of WHC in wetting were all low, both in field and in the experiments, less than 0.1 g (H2O) g-1 (soil)·day-1. None of the three parameters can be considered as fixed characteristics of forest soils.
基金funded by an ERASMUS+(EPPKA2-Cooperation for innovation and the exchange of good practices,CBHE-JP-Capacity building in higher education)within the project “Educational capacity strengthening for risk management of non-native aquatic species in Western Balkans(Albania,Bosnia and Herzegovina and Montenegro)-RiskMan”(project reference:619384-EPP-1-2020-1-TR-EPPKA2-CBHEJP)the national research project“Monitoring the species diversity and abundance of non-native species in the Slovenian Sea”and the Slovenian Research Agency(research core funding No.P1-0237)the Croatian Science Foundation for the support under Project No.HRZZ-IP-2019-04-6702(Benthic NIS).
文摘Globally,marine bioinvasions threaten marine ecosystem structure and function,with the Mediterranean Sea being one of the most affected regions.Such invasions are expected to increase due to climate change.We conducted a risk screening of marine organisms(37 fishes,38 invertebrates,and 9 plants),both extant and‘horizon’(i.e.,not present in the area but likely to enter it).Based on expert knowledge for the Eastern Adriatic Sea coasts of Slovenia,Croatia,and Montenegro,screenings were conducted under both current and predicted climate conditions indicating with an increase in sea surface temperature and salinity of the Adriatic Sea together with changes in precipitation regime.Our aims were to:(1)identify non-native extant and horizon marine species that may pose threats to native biodiversity and(2)evaluate the risk of invasiveness of the selected species under current and predicted climate conditions.Of the 84 species screened,there was an increase in those ranked as‘high risk’from 33(39.3%)under current climate conditions and to 47(56.0%)under global warming scenarios.For those ranked as‘very high’risk,the increase was from 6(7.1%)to 21(25.0%).Amongst the screened species,the already established high-risk species Pacific oyster Magallana gigas and Atlantic blue crab Callinectes sapidus represent a threat to ecosystem services.Given the under-representation of marine species in the current European Union List,the species we have ranked as high to very high risk should be included.
基金funded by the National Natural Science Foundation of China(No.51978099)Chongqing Talents Plan for Young Talents(CQY201905062).
文摘Greenhouse gas emissions from wetlands are significantly promoted by global nitrogen input for changing the rate of soil carbon and nitrogen cycling,and are substantially affected by soil labile carbon and nitrogen conversely.However,the driving mechanism by which soil labile carbon and nitrogen affect greenhouse gas emissions from wetland ecosystems under global nitrogen input is not well understood.Working out the driving factor of nitrogen input on greenhouse gas emissions from wetlands is critical to reducing global warming from nitrogen input.Thus,we synthesized 72 published studies(2144 paired observations)of greenhouse gas fluxes and soil labile compounds of carbon and nitrogen(ammonium,nitrate,dissolved organic carbon,soil microbial biomass nitrogen and carbon),to understand the effects of labile carbon and nitrogen on greenhouse gas emissions under global nitrogen input.Across the data set,nitrogen input significantly promoted carbon dioxide,methane and nitrous oxide emissions from wetlands.In particular,at lower nitrogen rates(<100 kg ha^(-1)$·yr^(-1))and with added ammonium compounds,freshwater wetland significantly promoted carbon dioxide and methane emissions.Peatland was the largest nitrous oxide source under these conditions.This meta-analysis also revealed that nitrogen input stimulated dissolved organic carbon,ammonium,nitrate,microbial biomass carbon and microbial biomass nitrogen accumulation in the wetland ecosystem.The variation-partitioning analysis and structural equation model were used to analyze the relationship between the greenhouse gas and labile carbon and nitrogen further.These results revealed that dissolved organic carbon(DOC)is the primary factor driving greenhouse gas emission from wetlands under global nitrogen input,whereas microbial biomass carbon(MBC)more directly affects greenhouse gas emission than other labile carbon and nitrogen.
基金supported by the Russian Science Foundation,Grant Number 19-74-20024.
文摘There are increasing findings of the bivalve transmissible neoplasia derived from the Pacific mussel Mytilus trossulus(MtrBTN)in populations of different Mytilus species worldwide.The Subarctic is an area where this disease has not yet been sought despite the fact that Mytilus spp.are widespread there,and M.trossulus itself is a boreal species.We used flow cytometry of the hemolymph,hemocytology,and histology to diagnose disseminated neoplasia in a sample of M.trossulus from Magadan in the subarctic Sea of Okhotsk.Neoplasia was identified in 11 of 214 mussels studied.Using mtDNA COI sequencing,we revealed genotypes identical or nearly identical to known MtrBTN ones in the hemolymph of most of the diseased mussels.Both MtrBTN evolutionary lineages have been identified,the widespread MtrBTN2,and MtrBTN1,so far only known from M.trossulus in British Columbia on the other side of the Pacific from Magadan.In addition,MtrBTN2 was represented by 2 common diverged mtDNA haplolineages.These conclusions were confirmed for selected cancerous mussels by molecular cloning of COI and additional nuclear and mtDNA genes.On the background of high genetic diversity,different cancers were similar in terms of ploidy(range 4.0–5.8 n)and nuclear-to-cell ratio.Our study provides the first description of neoplasia and MtrBTN in mussels from the Sea of Okhotsk and from the Subarctic,of both MtrBTN1 and MtrBTN2 in the same mussel population,and the first direct comparison between these transmissible cancers.
基金funded by the Russian Foundation for Basic Research(project No.19-04-00270)the Ministry of Science and Higher Education of Russia(projects No.AAAA-A18-118012390161-9,No.АААА-А17-117033010132-2,No.МК-1720.2019.4,and No.0793-2020-0005)the Deutsche Forschungsgemeinschaft(WI 1902/7 and RI 809/21 within the priority programme 1372:“Tibetan Plateau:Formation–Climate–Ecosystems”[TiP]).
文摘The high-elevation Tibetan Plateau(western China)is inhabited by a unique,though not particularly species-rich,community of organisms.We explored the species content and evolutionary history of the Tibetan Plateau endemic freshwater snail genus Tibetoradix.Phylogenetic relationships within the genus were reconstructed based on available sequence data.We used a single-rate Poisson Tree Processes approach for species delimitation and compared putative species-level clades with already described taxa.We found that the genus consists of at least 6 species,of which we described 4 as new to science.Shell and soft body morphology was examined and the radula in Tibetoradix was described for thefirst time.Based on ourfindings,the diversification of the genus did not result in a prominent morphological differentiation and a number of species can be regarded as morphologically cryptic.Single species found in different drainage areas indicate relatively good passive dispersal abilities of the snails.The allopatric distribution of the species could result from competitive exclusion between them.The absence of Tibetoradix spp.outside the Tibetan Plateau could be explained by a scenario of an“evolutionary trap”,where adaptations to high elevation conditions prevented the taxa from a successful colonization of lower elevations.
基金supported by 2024 Guizhou Basic Research Plan(Natural Science)Project,China(Foundation of Guizhou science cooperation-ZK[2024]General 490)the National Natural Science Foundation of China(No.31560107).
文摘The mutualistic symbiotic system formed by clumping arbuscular mycorrhizal fungi(AMF)and plants can remediate heavy metal-contaminated soils.However,the specific mechanisms underlying the interaction between AMF and inter-root microbial communities,particularly their impact on organic phosphorus(P)cycling,remain unclear.This study investigated the gene regulation processes involved in inter-root soil phosphorus cycling in wetland plants,specifically Iris tectorum,following inoculation with AMF under varying concentrations of chromium(Cr)stress.Through macro-genome sequencing,we analyzed the composition and structure of the inter-root soil microbial community associated with Iris tectorum under greenhouse pot conditions.The results demonstrated significant changes in the diversity and composition of the inter-root soil microbial community following AMF inoculation,with Proteobacteria,Actinobacteria,Chloroflexi,Acidobacteria,and Bacteroidetes being the dominant taxa.Under Cr stress,species and gene co-occurrence network analysis revealed that AMF promoted the transformation process of organic phosphorus mineralization and facilitated inorganic phosphorus uptake.Additionally,network analysis of functional genes indicated strong aggregation of(pstS,pstA,pstC,TC.PIT,phoR,pp-gppA)genes,which collectively enhanced phosphorus uptake by plants.These findings shed light on the inter-root soil phosphorus cycling process during the co-remediation of Cr-contaminated soil by AMF-Iris tectorum symbiosis,providing valuable theoretical support for the application of AMF-wetland plant symbiosis systems to remediate heavy metal-contaminated soil.
基金This work was partially supported by the USDA/NIFA Interagency Climate Change Grant Proposal number 2014-02114[Project number 6657-12130-002-08I,Accession number 1003011]under the Multi-Partner Call on Agricultural Greenhouse Gas Research of the FACCE-Joint Program Initiative.The German BLE and FACCE-JPI funded the German participants of the“DesignerChar4Food”(D4F)project(CK:Project No.2814ERA01A,NW-M:Project No.2814ERA02A)the Spanish colleagues(JME and TFM)were funded by FACCE-CSA no 276610/MIT04-DESIGN-UPVASC and IT-932-16,MLC thanks the Spanish Ministry of Science,Innovation and Universities,project#RTI2018-099417-B-I00+3 种基金cofinanced with EU FEDER funds and US colleagues(JN,JI and KS)were funded by The USDA-National Institute of Food and Agriculture(Project#2014-35615-21971)USDA-ARS CHARnet and GRACENet programs–D4F greatly stimulated discussions.Any opinions,findings,or recommendation expressed in this publication are those of the authors and do not necessarily reflect the view of the USDAThis work was also partially supported by the National Natural Science Foundation of China under a Grant number of 41501339,21677119,21277115,41301551,21407123,Jiangsu Province Science Foundation for Youths under a grant number of BK20140468,sponsored by Qing Lan ProjectOpen access funding provided by Natural Resources Institute Finland(LUKE).
文摘Various studies have established that feedstock choice,pyrolysis temperature,and pyrolysis type influence final biochar physicochemical characteristics.However,overarching analyses of pre-biochar creation choices and correlations to biochar characteristics are severely lacking.Thus,the objective of this work was to help researchers,biochar-stakeholders,and practitioners make more well-informed choices in terms of how these three major parameters influence the final biochar product.Utilizing approximately 5400 peer-reviewed journal articles and over 50,800 individual data points,herein we elucidate the selections that influence final biochar physical and chemical properties,total nutrient content,and perhaps more importantly tools one can use to predict biochar’s nutrient availability.Based on the large dataset collected,it appears that pyrolysis type(fast or slow)plays a minor role in biochar physico-(inorganic)chemical characteristics;few differences were evident between production styles.Pyrolysis temperature,however,affects biochar’s longevity,with pyrolysis temperatures>500℃ generally leading to longer-term(i.e.,>1000 years)half-lives.Greater pyrolysis temperatures also led to biochars containing greater overall C and specific surface area(SSA),which could promote soil physico-chemical improvements.However,based on the collected data,it appears that feedstock selection has the largest influence on biochar properties.Specific surface area is greatest in wood-based biochars,which in combination with pyrolysis temperature could likely promote greater changes in soil physical characteristics over other feedstock-based biochars.Crop-and other grass-based biochars appear to have cation exchange capacities greater than other biochars,which in combination with pyrolysis temperature could potentially lead to longer-term changes in soil nutrient retention.The collected data also suggest that one can reasonably predict the availability of various biochar nutrients(e.g.,N,P,K,Ca,Mg,Fe,and Cu)based on feedstock choice and total nutrient content.Results can be used to create designer biochars to help solve environmental issues and supply a variety of plant-available nutrients for crop growth.
基金This study was supported financially by National key R&D Program of China(2019YFD0901502 and 2020YFD0901202)National Natural Science Foundation of China(41806110 and 41506151)grants。
文摘Understanding the reproductive characteristics of a species is of crucial for accurate stock assessment and management plans to ensure sustainable fisheries.In this study,the size at 50%sexual maturity(L50)parameters in different bio-ecological provinces were estimated for bigeye tuna,Thunnus obesus,sampled from the Eastern Pacific Ocean tuna fisheries-dependent survey from 2013 to 2019.The overall sex ratio of the catch during the sampling differed significantly from 1:1.Bigeye tuna exhibit sexual dimorphism in the growth of males and females,with a clear shift in predominance from female to male with increasing sizes.In the North Pacific Sub-tropical Gyre(east)(NPST-east),North Pacific Tropical Gyre(NPTG),Pacific North Equatorial Countercurrent(PNEC),and Pacific Equatorial Divergence(PEQD),females(meals)reached sexual maturity round 102 cm(106 cm),106 cm(100 cm),125 cm(110 cm),and 113 cm(110 cm),respectively,the estimated L50 of bigeye tuna was 124.08 cm,121.97 cm,139.92 cm and 132.45 cm,respectively.The degree of populations mixing between equatorial(PNEC and PEQD)and high-latitude regions(NPST-east and NPTG)is extremely small,but it is reasonably high between the NPST-east and NPTG or PNEC and PEQD.These parameters were significantly different,suggesting the occurrence of a spatial difference in the size-at-maturity of bigeye tuna between these bio-ecological provinces.The findings of this study provide the key information for understanding the life history of bigeye tuna in the Eastern Pacific Ocean and will contribute to the conservation and sustainable yield of this species.
文摘With the extirpation of apex predators from many North American systems, coyotes Canis latrans have become the de facto top predator and are ubiquitous members of most ecosystems. Keystone predators aid in maintaining ecosystem function by regulating the mammal community through direct predation and instilling the landscape of fear, yet the value of coyotes regulating systems to this capacity is understudied and likely variable across environments. Since coyotes are common in the Midwestern United States, we utilized camera traps and occupancy analyses to as- sess their role in regulating the distribution of mammalian herbivores in a fragmented suburban ecosystem. Forest cover was a strong positive predictor of white-tailed deer Odocoileus virginianus detection, while coyote occurrence had a negative effect. Coyotes exerted a negative effect on squirrel (Sciurus spp.) and eastern cottontail rabbit Sylvilagus floridanus occurrence, while urban cover was a positive predictor for the prey species' occurrence. These results suggest all 3 species behaviorally avoid coyotes whereby deer seek denser forest cover and squirrels and cottontails mitigate risk by increasing use of urban areas. Although previous studies reveal limited influence of coyote on the rest of the carnivore guild in suburban systems, we suggest coyotes play an important role in regulating the herbivorous mammals and hence may provide similar eco- logical, benefits in urban/suburban forest fragments through trophic cascades. Furthermore, since hunting may not be allowed in urban and suburban habitats, coyotes might also serve as the pri- mary regulator of nuisance species occurring at high abundance such as white-tailed deer and squirrels.