Evolution of Hydrodynamic Field, Oil-Gas Migration and Accumulation in Songliao Basin, China

The oil-gas migration and accumulation in the Songliao Basin were analyzed in the view of fluid dynamics by the authors. The key point of fluid dynamics is hydrodynamics. Oil-gas migration and accumulation are related closely with formation and evolution of hydrodynamic field. Based on abundant data, initial formation pressure and other parameters, such as water head were studied. They can be used to understand the present distribution of hydrodynamic field and its hydrochemical features. Generally, the hydrodynamic field in the basin is obviously asymmetrical. In its north and east part, there are the areas of centripetal flow caused by topographic relief when meteoric water permeate downwards. Its south part is an evaporation-concentration area. The central depression is an area of centrifugal flow driven by sediment compaction and its cross-formational flow area. Only at the basin margin and in the local uplifted and denudated area are the meteoric water permeating downwards areas. The centrifugal flow driven by sediment compaction is the main dynamic factor that induces oil-gas migration and accumulation and its formation period corresponding to the main stage of oil-gas migration and accumulation. Moreover, the evolution of hydrodynamic field has the cyclic property, which results in phased oil-gas migration by stages, and further dominates the terraced annular oil and gas distribution, concentric with their corresponding sags.

Autumn migration routes and wintering areas of juvenile Chinese Egrets(Egretta eulophotes)revealed by GPS tracking

Background:The vulnerable Chinese Egret(Egretta eulophotes)is a long-distance migratory waterbird whose migration and wintering information is poorly understood.This study aims to identify the autumn migration routes and wintering areas of juvenile Chinese Egrets and determine the migration movement traits of this species.Methods:Thirty-nine juvenile Chinese Egrets from the Fantuozi Island,an uninhabited offshore island with a large breeding colony of Chinese Egrets in Dalian,China,were tracked using GPS/GSM transmitters.Some feathers from each tracked juvenile were collected for molecular identification of sex in the laboratory.The GPS locations,recorded at 2-h intervals from August 2018 to May 2020,were used for the analyses.Results:Of the 39 tracked juveniles,30 individuals began their migration between September and November,and 13 successfully completed their autumn migration between October and November.The juveniles migrated southward via three migration routes,coastal,oceanic and inland,mainly during the night.The migration duration,migration distance,flight speed,and stopover duration of the 13 juvenile egrets that completed migration averaged 5.08±1.04 days,3928.18±414.27 km,57.27±5.73 km/h,and 23.08±19.28 h,respectively.These juveniles wintered in the coastal wetlands of Southeast Asia including those in the Philippines,Vietnam,and Malaysia,and only one successfully began its spring migration in June 2020.Conclusions:This study newly finds that the oceanic route taken by juvenile Chinese Egrets,suggesting that the juveniles are able to fly over the Pacific Ocean without a stopover.Moreover,our novel data indicate that coastal wetlands along the East Asian-Australasian Flyway are important areas for both autumn migration stopover and the wintering of these juveniles,suggesting that international cooperation is important to conserve the vulnerable Chinese Egret and the wetland habitats on which it depends.

Research in migration route of hatchery released Chinese shrimp(Fenneropenaeus chinensis) in the Bohai Bay using method of SSR marker

This study provides new insights for the hatchery released Chinese shrimp(Fenneropenaeus chinensis),including proportion,dynamic migration route,after they were released into nature for stock enhancement using a new strategy quite different than ever.Chinese shrimp were sampled at 22 survey stations during two investigation voyages acrossing 74 survey stations in the Bohai Sea from July 16 to August 9 in 2015.Among 289 sampled individuals during the second voyage,totally 155 shrimps were identified as hatchery shrimp released into the Laizhou Bay at mid-May in 2015 based on finger-print of eight SSR(simple sequence repeats)markers,and the proportion of hatchery released shrimp in recapture samples were from 41.30%–85.71%in each station with an average value 53.63%,which verified a previous view point that up to 90%of autumn season Chinese shrimp landing in the Bohai Sea were composed of hatchery released.Meanwhile,the dynamic migration route of hatchery released shrimp revealed that part of released shrimp migrated heading northwest along the west coast of the Bohai Sea up to the Bohai Bay but just remained at the Laizhou Bay until over-wintering migration at midOctober when they initiate over-wintering migration.Present unnatural spring season shrimp fishing model cut the throat of spawner shrimp chance to swim back to their respective spawning plants at each spring,it still no chance to clarify whether the hatchery released shrimp could replenish to the reproduce population and complete a whole life cycle as same as their natural relatives.

Migration routes and differences in migration strategies of Whooper Swans between spring and autumn

Long-distance migratory birds travel more rapidly in spring than in autumn,as they face temporal breeding constraints.However,several species travel slower in spring owing to environmental influences,such as food availability and wind conditions.GPS trackers were attached to 17 Whooper Swans(Cygnus cygnus) inhabiting northeastern Mongolia,to determine their migration routes and stopover sites in spring and autumn.Differences between spring and autumn migrations,migration-influencing parameters,and the effect of spring stopover site temperatures were analyzed.Six swans completed perfect tours between their wintering and breeding sites,and these data were used for analysis.Spring migration lasted 57 days,with 49.2 days spent at 3.7 stopover sites.Autumn migration lasted 21.5 days,with 17.5 days spent at 1.0 stopover sites.Thus,the swans traveled more rapidly in autumn than in spring.Migration distance,number of stopovers,migration speed,and straightness were important migration determinants in both spring and autumn.Migration distance,stopover duration,number of stopovers,daily travel speed,travel duration,and migration speed differed significantly between spring and autumn.During spring migration,the temperature at the current stopover sites and that at the future stopover sites displayed significant variations(t=1585.8,df=631.6,p <0.001).These findings are critical for the conservation and management of Whooper Swans and their key habitats in East Asian regions,and the data are anticipated to make a particularly significant contribution toward developing detailed management plans for the conservation of their key habitats.

Autumn migration routes of fledgling Chinese Egrets(Egretta eulophotes)in Northeast China and their implications for conservation

The Chinese Egret(Egretta eulophotes)is a globally threatened bird species living on the coast and islands of Liaoning,northeastern China,mainly in summer.To further protect the breeding population of Chinese Egrets,it is important to understand the current protection status of their distribution sites at pre-migration period and migration routes.Thirty-three individuals were tagged with satellite transmitters at Fantuo Island in Changhai and Xingren Island in Zhuanghe,Liaoning Province,northeastern China,in July of 2016,2017,and 2018,to identify important distribution sites during the pre-migration period,as well as detailed migration routes.The results showed that coastal mudflats in Liaoning and the west coast of North Korea were important feeding and roosting sites for fledgling Chinese Egrets from August to September.The home range sizes in August were significantly larger than in September.The eastern coast from Shandong to Guangdong,as well as Taiwan,China,and Manila Bay and Galileo Islands in the Philippines,were important stopover sites during fall migration.Specifically,we found that the egrets’autumn migration could be divided into four routes,i.e.,sea-crossing migration(SCM),coastal migration(CM),inland migration(IM),and mixed migration(MM).The migration distance,timing,speed,and straightness of the four routes also differed.The SCM routes were the straightest,and had the fastest migration speed and shortest travel time,while the IM routes had the lowest straightness and speed,and the longest duration.Manila Bay and Bohol Island in the Philippines,the west coast of Tanintharyi in Myanmar,and the Zengwun River Estuary in Taiwan,China,were wintering sites.Our findings on the key distribution sites along pre-migration and fall migration routes,including some stopover sites,have important implications for the conservation of and global action plan development for the vulnerable Chinese Egret.

Migration routes,behavior and protection status of Eurasian Spoonbills(Platalea leucorodia)wintering in China

Background:The Eurasian Spoonbill(Platalea leucorodia)occurs throughout Eurasia and North and sub-Saharan Africa,with three recognized subspecies and six geographically distributed populations.However,in China,we knew almost nothing about migration routes,habitat use and effectiveness of current site protection measures for this species.Methods:We deployed Global Positioning System/Global System for Mobile Communications(GPS/GSM)satellite trackers on 29 Eurasian Spoonbills captured in summer in Mongolia and northeastern China,to obtain complete migration routes data from 10 individuals from 19 complete migration episodes.Results:Tracking data showed no geographical overlap during the annual cycle in Eurasian Spoonbills marked in the two main summering areas.Birds marked in the Naoli River Basin in Heilongjiang Province,China,wintered along the Jiangsu coastline in China,while Eurasian Spoonbills from two discrete summering areas(in Inner and western Mon-golia)overwintered inland in the Yangtze River floodplain of China.Excluding the single Inner Mongolian bird,spring migration was significantly faster than autumn migration in the other two groups of birds.Eurasian Spoonbills mainly used water,wetland and grassland habitats in summer,but almost exclusively water in winter.Lack of protection of staging sites used by all the birds in spring and poor levels of protection throughout the annual cycle for western Mongolian birds(5-22%)gives considerable cause for concern,although sites used in other time by East Mongolian and Naoli River birds in the rest of their annual life cycle enjoyed good levels of protection(49-95%).Conclusions:These results revealed previously unknown relationships between summering and wintering areas,migration routes and stopover sites for Eurasian Spoonbills wintering in China,suggesting the existence of discrete biogeographical population units.They also identified winter habitat use of Eurasian Spoonbills in China,confirming open water habitats as being critical throughout the annual cycle,although based on small sample size,gaps in cur-rent site safeguard networks for these populations.

Citrine Wagtail migration on the Indo-European flyway:a first geolocator track reveals alternative migration route and endurance flights to cross ecological barriers

Most long-distance migrating passerines that breed in Europe spend their winters in Africa,with only a few species migrating eastward to spend the non-breeding period in South Asia.The use of the Indo-European flyway is rare and has been poorly studied so far.However,it is extremely interesting as within that system we are currently witnessing a recent range expansion of European breeding long distance migrants and thus the lengthening of migration routes.It may therefore conceal a unique migratory strategies and behaviour that can help us to understand the underlying factors and mechanisms determining the evolution of migration routes,strategies and breeding range extinction.Based on light-level geolocator we reveal a first track of the Citrine Wagtail(Motacilla citreola)migration,providing insight into the migration pattern,timing and behaviour of the species that recently has extended its migration routes.Unexpectedly,the studied individual did not retrace a recent range expansion that runs north and east from the Caspian Sea but followed a migration route running south form the Caspian sea,suggesting possible presence of an alternative species range expansion.The overall migration distance between the breeding site in Poland and the non-breeding site in Pakistan was about 10,420 km and included two endurance movement phases(920 and 2240 km)covering 30%of the whole journey length,with an average movement speed of 574 km/day.We explain this migration behaviour as an adaptation for crossing the ecological barriers imposed by arid environments.

Detour for the inexperienced? Migration count data suggest mostly juvenile Greater Spotted Eagles appear in coastal peninsulas in China

Soaring bird migration often relies on suitable terrain and airflow;therefore,route selection is vital for successful migration.While age and experience have been identified as key factor influencing migration route selection among soaring raptors in the African-Eurasian Flyway,how they shape the migration route of soaring raptors in East Asia is still largely unknown.In this study,we investigated potential variations in the routes and timing in autumn migration of juvenile and older soaring birds,using count data of Greater Spotted Eagles(Clanga clanga)from two coastal sites and two inland sites in China.From 2020 to 2023,we recorded a total of 340 individuals,with the highest site averaging over 90 individuals per autumn,making it one of the world’s top single-season counts and thus a globally important site for this species.We found that 82% and 61% records from coastal sites were juveniles,significantly higher than inland sites(15% and 24%).Juveniles at all four sites exhibited markedly earlier median passage time than non-juveniles,with brief overlapping in their main migration periods.Both coastal sites are located on the tip of peninsulas stretching southwest,requiring long overwater flights if crossing the Bohai Bay or Beibu Gulf,which would be energetically demanding and increase mortality risk.Experienced individuals may have learned to avoid such terrain and subsequent detour,while juveniles are more prone to enter these peninsulas due to lack of experience and opportunities for social learning,or following other raptor species that are more capable of powered flight.Our findings highlight the importance of age and experience in migration route selection of large soaring birds.

An Investigation on the Effect of Migration Strategy on Parallel GA-Based Shortest Path Routing Algorithm

Genetic algorithm (GA) is one of the alternative approaches for solving the shortest path routing problem. In previous work, we have developed a coarse-grained parallel GA-based shortest path routing algorithm. With parallel GA, there is a GA operator called migration, where a chromosome is taken from one sub-population to replace a chromosome in another sub-population. Which chromosome to be taken and replaced is subjected to the migration strategy used. There are four different migration strategies that can be employed: best replace worst, best replace random, random replace worst, and random replace random. In this paper, we are going to evaluate the effect of different migration strategies on the parallel GA-based routing algorithm that has been developed in the previous work. Theoretically, the migration strategy best replace worst should perform better than the other strategies. However, result from simulation shows that even though the migration strategy best replace worst performs better most of the time, there are situations when one of the other strategies can perform just as well, or sometimes better.

Ontogenetic difference of beak elemental concentration and its possible application in migration reconstruction for Ommastrephes bartramii in the North Pacific Ocean

The migration route of oceanic squid provides critical information for us to understand their spatial and temporal variations.Mark-recapture and electronic tags tend to be problematic during processing.Cephalopod hard structures such as the beak,containing abundant ecological information with stable morphology and statolithlike sequences of growth increments,may provide information for studying spatio-temporal distribution.In this study,we developed a method,which is based on elemental concentration of beaks at different ontogenetic stages and sampling locations,to reconstruct the squid migration route.We applied this method to Ommastrephes bartramii in the North Pacific Ocean.Nine trace elements were detected in the rostrum sagittal sections(RSS)of the beak using laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS).For those elements,significant differences were found between the different ontogenetic stages for phosphorus(P),copper(Cu)and zinc(Zn).Sodium(Na),P and Zn were chosen as indicators of sea surface temperature(SST)and a regression model was estimated.The high probability of occurrence in a particular area represented the possible optimal squid location based on a Bayesian model.A reconstructed migration route in this study,combining all the locations at different ontogenetic stages,was consistent with that hypothesized in previous studies.This study demonstrates that the beak can provide useful information for identifying the migration routes of oceanic squid.

Annual spatio-temporal migration patterns of Hooded Cranes wintering in Izumi based on satellite tracking and their implications for conservation

Background: The Hooded Crane(Grus monacha) is listed as a vulnerable species by IUCN. Knowledge about the migration of the Hooded Crane is still limited. Here we reported the spatio-temporal migration patterns of Hooded Cranes wintering in Izumi, Japan, as well as important stopover areas for their conservation.Methods: Four adult and five subadult cranes, all wintering in Izumi, Japan, were fitted with satellite transmitters(GPS–GSM system) at their stopover sites in northeastern China in 2014 and 2015. We analyzed the time and duration of adults and subadults in spring and autumn migration, as well as the time and duration they stayed in breeding and wintering ground. In addition, we analyzed the land use of the cranes in stopover areas.Results: Adult cranes took much longer time to migrate both north in spring(mean days) compared with subadult cranes(15.3 and 5.2 days, respectively). H= 44.3 days) and south in fall(mean = 54.0 owever, the subadults had longer wintering(mean = 149.8 days) and nomadic(breeding season for adults) seasons(mean d with adults(133.8 and 122.3 days, respectively). Three important stopover areas have been= 196.8 days) compare identified: the region around Muraviovka Park in Russia, the Songnen Plain in China, and the west coast of South Korea, where cranes spent most of their migration time(62.2 and 85.7% in spring and autumn, respectively). During migration, nomadic period and winter, Hooded Cranes usually stay in croplands for resting and feeding. In non-wintering season, less than 6% of stopover sites were located within protected areas.Conclusion: Overall, our results contribute to understanding the annual spatio-temporal migration patterns of Hooded Cranes in the eastern flyway, and planning conservation measures for this species.

Migration and wintering of vulnerable adult Chinese Egrets(Egretta eulophotes)revealed by GPS tracking

Knowledge of migratory bird requirements is critical to developing conservation plans for vulnerable migratory species.This study aimed to determine the migration routes,wintering areas,habitat uses,and mortalities of adult Chinese Egrets(Egretta eulophotata).Sixty adult Chinese Egrets(31 females and 29 males)on an uninhabited offshore breeding island in Dalian,China were tracked using GPS satellite transmitters.GPS locations recorded at2 h intervals from June 2019 to August 2020 were used for analysis.A total of 44 and 17 tracked adults completed their autumn and spring migrations,respectively.Compared with autumn migration,tracked adults displayed more diverse routes,higher number of stopover sites,slower migration speed,and longer migration duration in the spring.Results indicated that migrant birds had different behavioral strategies during the two migratory seasons.The spring migration duration and stopover duration for females were significantly longer than those for males.A positive correlation existed between the spring arrival and spring departure dates,as well as between the spring arrival date and stopover duration.This finding indicated that the egrets that arrived early at the breeding grounds left the wintering areas early and had a shorter stopover duration.Adult birds preferred intertidal wetlands,woodlands,and aquaculture ponds during migration.During the wintering period,adults preferred offshore islands,intertidal wetlands,and aquaculture ponds.Adult Chinese Egrets showed a relatively low survival rate compared with most other common ardeid species.Dead specimens were found in aquaculture ponds,indicating human disturbance as the main cause of death of this vulnerable species.These results highlighted the importance of resolving conflicts between egrets and human-made aquaculture wetlands and protecting intertidal flats and offshore islands in natural wetlands through international cooperation.Our results contributed to the hitherto unknown annual spatiotemporal migration patterns of adult Chinese Egrets,thereby providing an important basis for the conservation of this vulnerable species.

Individual consistency in spatiotemporal characteristics of migratory Whimbrels in the East Asian-Australasian Flyway

Many migratory birds exhibit interannual consistency in migration schedules,routes and stopover sites.Detecting the interannual consistency in spatiotemporal characteristics helps understand the maintenance of migration and enables the implementation of targeted conservation measures.We tracked the migration of Whimbrel(Numenius phaeopus)in the East Asian-Australasian Flyway and collected spatiotemporal data from individuals that were tracked for at least two years.Wilcoxon non-parametric tests were used to compare the interannual variations in the dates of departure from and arrival at breeding/nonbreeding sites,and the inter-annual variation in the longitudes when the same individual across the same latitudes.Whimbrels exhibited a high degree of consistency in the use of breeding,nonbreeding,and stopover sites between years.The variation of arrival dates at nonbreeding sites was significantly larger than that of the departure dates from nonbreeding and breeding sites.Repeatedly used stopover sites by the same individuals in multiple years were concentrated in the Yellow Sea coast during northward migration,but were more widespread during southward migration.The stopover duration at repeatedly used sites was significantly longer than that at sites used only once.When flying across the Yellow Sea,Whimbrels breeding in Sakha(Yakutia)exhibited the highest consistency in migration routes in both autumn and spring.Moreover,the consistency in migration routes of Yakutia breeding birds was generally higher than that of birds breeding in Chukotka.Our results suggest that the northward migration schedule of the Whimbrels is mainly controlled by endogenous factors,while the southward migration schedule is less affected by endogenous factors.The repeated use of stopover sites in the Yellow Sea coast suggests this region is important for the migration of Whimbrel,and thus has high conservation value.

Abnormal formation pressures and oil-gas migration in China

Abnormal formation pressures occur not only in marine strata but also in terrestrialsedimentary basins in China.It develops most in Tertiary,followed by Mesozoic and Palaeozoic.Residualpressure decreases with the age of strata.Abnormal pressure raainly results from imbalanced compaction andhydrocarbon generation,and depends on various geological conditions.The secondary cause is the uplift ofcrust at the late stage and the transformation of clay minerals.Practical data show that the abnormal forma-tion pressure provides the dynamic force and passages for the primary migration of oil-gas,and in reservoirs,itcan affect the distribution of flow potential,which controls the migration direction and the aocumulation placeof oil and gas.

Individual repeatability in timing and spatial flexibility of migration routes of trans-Saharan migratory raptors

Satellite-tracking technology has allowed scientists to make a quantum leap in the field of migration ecology. Nowadays, the basic description of migratory routes of many species of birds has been reported. However, the investigation of bird migration at individual level （i.e. repeatability in migratory routes and timing） still remains seldom explored. Here, we investigated repeated migratory trips of a trans-Saharan endangered migratory raptor, the Egyptian Vulture Neophron percnopterus, tracked by GPS satellite telemetry. We compared between- and within-individual variation in migratory routes and timing in order to assess the degree of repeatability （or conversely, the flexibility） in migration. To this end, we analysed a dataset of 48 trips （23 springs and 25 autumns） recorded for six adult birds during 2007-2013. Our results showed consistent migration timing at the individual level, both in spring and autumn. Interestingly, there was a high degree of flexibility in the routes followed by the same individual in different years, probably due to variations in meteorological conditions. Contrary to expectations of a faster migration in spring than in autumn owing to a time-minimization strategy for breeding, birds spent less time in autumn migration （13 ± 2 days, range = 9-18 d） than in spring migration （19 ± 3 days, range = 13-26 d）, which can be explained by differences in environmental con- ditions en route. Egyptian vultures showed a consistent clockwise loop migration through western Africa, following more easterly routes in autumn than in spring. Finally, our results provide supporting evidence of low phenotypic plasticity in timing of migration （i.e. strong endogenous control of migration） and high flexibility in routes [Current Zoology 60 （5）： 642-652, 2014].

Origin area and migration route: Chloroplast DNA diversity in the arctic-alpine plant Koenigia islandica

The Hengduan Mountains(henceforth H-D Mountains) on the Tibet Plateau are a distribution and diversity center for many alpine genera. We examine patterns of genetic variation in an arctic-alpine plant to evaluate the possibility that the H-D Mountains constitute the area of origin of the species as well as to uncover postglacial migration routes. 220 individuals of the arctic-alpine plant Koenigia islandica were sampled from 26 populations distributed in western China and northern Finland. DNA haplotypes were identified using restriction site analysis of two chloroplast DNA intergene spacer regions, atpB-rbcL and trnL-trnF. We examined the geographical distribution of haplotype diversity in relation to latitude, and also compared various indices of diversity in putatively glaciated and unglaciated regions. Patterns of migration were inferred using nested clade analysis. A total of 25 haplotypes were detected. High haplotype diversity was found in the H-D Mountains. H3 and its radiated haplotypes were distributed in the Himalayas. Two haplotypes were fixed concurrently in the H-D Mountains and northern Finland. High genetic diversity of K. islandica and high species diversity of K. islandica are expected in the origin area. Our observations suggest that the H-D Mountains are not only the place of origin of K. islandica, but also the refugia for K. islandica on the Tibet Plateau. What is more, the migration route for the arctic-alpine plant K. islandica must have originated in the region defined by the H-D Mountains in western China extending northward to the Arctic circumpolar, and moved westward along the Himalayas, then northward across the Altay Mountains and the Central Siberian Plateau at different time periods.

Bio-Imitation of Mexican Migration Routes to the USA with Slime Mould on 3D Terrains

Plasmodium ofPhysarum polycephalum （P. polycephalum） is a large single cell visible by an unaided eye. It shows sophisticated behavioural traits in foraging for nutrients and developing an optimal transport network of protoplasmic tubes spanning sources of nutrients. When placed in an environment with distributed sources of nutrients the cell computes＇ an optimal graph spanning the nutrients by growing a network of protoplasmic tubes. P. polycephalum imitates development ofman-made transport networks of a country when configuration of nutrients represents major urban areas, We employed this feature of the slime mould to imitate mexican migration to USA. The Mexican migration to USA is the World＇s larger migration system. We bio-physically imitated the migration using slime mould P. poIycephalum. In laboratory experiments with 3D Nylon terrains of USA we imitated development of migratory routes from Mexico-USA border to ten urban areas with high concentration of Mexican migrants. From results of laboratory experiments we extracted topologies of migratory routes, and highlighted a role of elevations in shaping the human movement networks.

草地贪夜蛾迁飞气象预报方法探索及应用

为了准确预报害虫的迁飞轨迹,将天气预报技术应用于迁飞性害虫的预测预报,基于天气预报平台,利用欧洲中心中短期气象数值预报产品以及大气环流形势及低层风动力对草地贪夜蛾(Spodoptera frugiperda)的迁飞路径、迁入时间(包括首见日及高峰日)、落区等进行预报,并基于2021年草地贪夜蛾迁飞的2次典型预报案,分析2021年草地贪夜蛾春季北迁至湖北(首见日)以及秋季南迁回湖北(高峰日)的典型天气过程以及迁飞层气象要素场,运用HYSPLIT轨迹模型模拟迁飞后向轨迹,再利用草地贪夜蛾田间监测数据、测报灯监测数据以及迁飞轨迹对预报结论进行验证。结果显示,2次典型预报案例的预报结论与草地贪夜蛾田间监测数据及测报灯监测数据以及轨迹模拟的情景吻合度较好,草地贪夜蛾迁入时间、落区及路径预报基本正确。研究表明,将天气预报技术应用于迁飞性害虫的预报具有实际可行性。

基于MaxEnt模型的甘草潜在适生区预测

甘草(Glycyrrhiza uralensis)是一种具有较高经济价值的多年生豆科(Leguminosae)草本中药材植物。本研究基于MaxEnt模型与甘草野生分布数据,模拟了甘草当代的适生分布区,以及甘草未来(2050年、2070年)不同情景下在中国的适生区分布,包括中等社会脆弱性和中等辐射强迫的折中碳排放情景(SSP2-4.5)、高等社会脆弱性和高等辐射强迫的折中碳排放情景(SSP5-8.5),并利用ArcGIS软件分析未来甘草适生区的分布及变化情况,影响甘草潜在适生区变化的环境因子。结果显示:(1)当前,甘草适生区位于内蒙古中西部、甘肃、宁夏、陕西北部、新疆和吉林东北部,即降水量少的中高纬度地区;未来不同情景下(SSP2-4.5和SSP5-8.5),甘草高适应区主要集中分布于内蒙古、甘肃、宁夏、陕西、山西、河北、吉林、新疆等地,且适生区面积发生扩张。(2)在全球气候变化背景下,甘草适生区迁移路线整体呈现由东向西、由北往南偏移,且均有向低降水量地区移动的趋势。(3)最冷季度的平均降水量、年均降水量、紫外线季节性变化是影响甘草适生区变化的主导环境因子。

不同气候情景下黄心梓木在我国的潜在适生区预测

【目的】预测不同气候情景下黄心梓木在我国的分布情况及其自然群体可能的迁移路线,为黄心梓木的保护和可持续利用提供科学依据,为濒危植物的潜在适生区预测和保护提供参考。【方法】基于当前和未来(2030s、2050s、2070s)4个时期的环境变量数据以及黄心梓木分布数据,利用MaxEnt模型模拟预测不同气候情景下黄心梓木在我国的潜在地理分布,综合分析限制其扩散的环境因子,制定针对性保护措施。【结果】1)MaxEnt模型各组曲线下面积(AUC)均高于0.9,模型预测结果非常准确。2)黄心梓木在我国的潜在适生区狭窄,当前适生区总面积为50416 km^(2),其中高适生区面积2309 km^(2),仅在黔南和黔西南部分地区分布,中适生区(面积14288 km^(2))在其周围分布,低适生区面积33819 km^(2),分布在贵州中部、广西、云南、四川等地;未来气候情景下,黄心梓木在我国的潜在适生区呈先扩张后收缩的变化趋势,其中高强迫(SSP5-8.5)情景下的2030s时期适生区总面积最大(70313 km^(2)),新增面积达当前适生区总面积的39%。3)最干月降水量(bio14)、海拔(bio20)、等温性(bio3)、年降水量(bio12)是限制黄心梓木分布的主导环境因子。4)未来气候情景下,黄心梓木潜在适生区的质心迁移方向总体为先向北移后向东南移。5)基于黄心梓木现状提出在高适生区范围内就地划分保护区,在湖北西部、重庆东北部等潜在适生区开展相关育种试验扩大其种植面积以及建立种质资源库等相关保护措施。【结论】黄心梓木在我国的潜在适生区较为狭窄且中、高适生区相对集中,大多分布在贵州西南部,广西、云南、四川、重庆以及湖北部分地区也可能有分布;目前黄心梓木的潜在适生区未达到饱和,预计适生区面积会持续扩增至2030s;未来气候情景下,黄心梓木潜在适生区面积呈先扩大后缩小的趋势;基于黄心梓木现状,建议以人为方式开展协助恢复其生境以及快速促进其种群扩大等相关保护措施。