Achieving high maize yields and efficient phosphorus(P)use with limited environmental impacts is one of the greatest challenges in sustainable maize production.Increasing plant density is considered an effective appro...Achieving high maize yields and efficient phosphorus(P)use with limited environmental impacts is one of the greatest challenges in sustainable maize production.Increasing plant density is considered an effective approach for achieving high maize yields.However,the low mobility of P in soils and the scarcity of natural P resources have hindered the development of methods that can simultaneously optimize P use and mitigate the P-related environmental footprint at high plant densities.In this study,meta-analysis and substance flow analysis were conducted to evaluate the effects of different types of mineral P fertilizer on maize yield at varying plant densities and assess the flow of P from rock phosphate mining to P fertilizer use for maize production in China.A significantly higher yield was obtained at higher plant densities than at lower plant densities.The application of single superphosphate,triple super-phosphate,and calcium magnesium phosphate at high plant densities resulted in higher yields and a smaller environmental footprint than the application of diammonium phosphate and monoammonium phosphate.Our scenario analyses suggest that combining the optimal P type and application rate with a high plant density could increase maize yield by 22%.Further,the P resource use efficiency throughout the P supply chain increased by 39%,whereas the P-related environmental footprint decreased by 33%.Thus,simultaneously optimizing the P type and application rate at high plant densities achieved multiple objectives during maize production,indicating that combining P management with cropping techniques is a practical approach to sustainable maize production.These findings offer strategic,synergistic options for achieving sustainable agricultural development.展开更多
Understanding the foraging behavior is essential for investigating seabird ecology and conservation,as well as monitoring the well-being of the marine environment.Breeding seabirds adopt diverse foraging strategies to...Understanding the foraging behavior is essential for investigating seabird ecology and conservation,as well as monitoring the well-being of the marine environment.Breeding seabirds adopt diverse foraging strategies to maximize energy gains and cope with the intensified challenges of parenting and self-maintenance.Such tradeoff may stem from the heterogeneity of food resources and the constraints of central place foraging.Nevertheless,abundant marine productivity could alleviate the energy limitation for seabirds,resulting in a consistent foraging approach.Here,we investigated the foraging strategy during the breeding season of a cryptic small-sized seabird,Swinhoe’s Storm-petrel(Hydrobates monorhis),in the Yellow Sea,a productive marginal sea of the Northwest Pacific.Using GPS tracking,we evaluated habitat preference,quantified the foraging strategy,and tested if environmental conditions and individual traits influence foraging trips.We found that Swinhoe’s Storm-petrels preferred nearshore areas with shallow water and engaged in primarily short foraging trips.Distinctive southeastward and southwestward strategies emerged when combining trip metrics,including foraging direction,duration,and maximum distance.The bathymetry,proximity to the coastline,and sea surface temperature differed in two foraging strategies.Foraging strategies exhibited flexibility between individuals,potentially explained by wing morphology,in which longer-winged birds are more likely to embark on longer-distance foraging trips.These findings highlight the impact of environmental factors and individual traits on seabirds’foraging decisions in productive marginal sea ecosystems.Our study also provides valuable insights into the foraging ecology of this Asian endemic storm-petrel.展开更多
Understanding the genetic basis underlying the local adaptation of nonmodel species is a fundamental goal in evolutionary biology.In this study,we explored the genetic mechanisms of the local adaptation of Forsythia s...Understanding the genetic basis underlying the local adaptation of nonmodel species is a fundamental goal in evolutionary biology.In this study,we explored the genetic mechanisms of the local adaptation of Forsythia suspensa using genome sequence and population genomics data obtained from specific-locus amplified fragment sequencing.We assembled a high-quality reference genome of weeping forsythia(Scaffold N50=7.3 Mb)using ultralong Nanopore reads.Then,genome-wide comparative analysis was performed for 15 natural populations of weeping forsythia across its current distribution range.Our results revealed that candidate genes associated with local adaptation are functionally correlated with solar radiation,temperature and water variables across heterogeneous environmental scenarios.In particular,solar radiation during the period of fruit development and seed drying after ripening,cold,and drought significantly contributed to the adaptive differentiation of F.suspensa.Natural selection exerted by environmental factors contributed substantially to the population genetic structure of F.suspensa.Our results supported the hypothesis that adaptive differentiation should be highly pronounced in the genes involved in signal crosstalk between different environmental variables.Our population genomics study of F.suspensa provides insights into the fundamental genetic mechanisms of the local adaptation of plant species to climatic gradients.展开更多
Reproduction investment is a prominent trade-off in life-history theory and is subject to strong selection pressure.The avian eggshell,as a crucial barrier between the bird embryo and the surrounding environment,under...Reproduction investment is a prominent trade-off in life-history theory and is subject to strong selection pressure.The avian eggshell,as a crucial barrier between the bird embryo and the surrounding environment,undergoes optimization under different environmental selection regimes to ensure the successful development of embryos,which can be linked to local adaptation.Therefore,understanding the variation in eggshell microstructure and composition in wild bird populations living in contrasting ambient environments is of great significance.In this study,we utilized electron microscope ultrastructure measurement and elemental analyses to measure and compare the microstructure and element composition of eggshells from three wild plover populations(Charadrius alexandrinus and C.dealbatus)residing in heterogeneous habitats across varied climatic zones.These populations include the high-altitude Qinghai Lake population,the temperate coastal Tangshan population,and the tropical coastal Zhanjiang population.Our findings revealed that the palisade layer was thinner in the Qinghai Lake population compared to its lowland populations.This difference might be attributed to hypoxia which facilitates the hatching process by allowing chicks to easily break through their shells.Additionally,the variations in the elemental composition of the eggshells among populations well reflected the distribution of element content in different geographical regions.The Qinghai Lake population displayed low zinc and low manganese levels but high calcium levels,while the Zhanjiang population exhibited high zinc,high iron,high manganese,and high phosphorus levels.Furthermore,these variations in elemental composition could also account for the observed microstructural differences among populations.Collectively,we propose that the dissimilarities in eggshell microstructure and elemental composition among populations could be attributed to adaptations to different environmental conditions.Our findings lay the groundwork for future research to explore the mechanisms behind the variations in eggshell characteristics among wild bird populations,and contribute to a broader understanding of biodiversity mechanisms.展开更多
China’s coastal wetlands provide breeding,migration stopover,and wintering habitats for about 230 waterbird species,which is more than a quarter of all waterbirds in the world.Large-scale and high intensity human act...China’s coastal wetlands provide breeding,migration stopover,and wintering habitats for about 230 waterbird species,which is more than a quarter of all waterbirds in the world.Large-scale and high intensity human activities have resulted in serious loss and degradation of coastal wetlands over the past half century,causing population declines in many waterbirds.Through a literature review and expert surveys,this article reviews conservation measures taken in recent decades to protect waterbirds in China’s coastal wetlands and provides recommendations for future conservation action from three aspects:policy and administration,habitat conservation and management,and multiparty participation.Over the past decades,many conservation legislation,regulations and action plans at the national level and more site-specific measures and interventions have been implemented,with notable improvement in the effectiveness in policy making and multi-stakeholder participation.Accordingly,some threats to waterbirds have been mitigated and many key sites for waterbirds have been designated as strictly protected nature reserves.However,some critical issues still remain,mostly related to habitat conservation and management,such as coastal wetland restoration,control of invasive Spartina alterniflora,control of environmental pollution,and improvement of artificial habitat quality.We highlight that protecting natural tidal wetlands and improving habitat quality are critical for the conservation of coastal waterbirds,especially those highly dependent on the intertidal wetlands.China has demonstrated strong commitment to ecological conservation and restoration for the future,in terms of both funding and policies for biodiversity and wetland ecosystems.It is important that this commitment to conserve coastal waterbirds is supported continuously by science-and evidence-based decisions and actions.展开更多
Background: Galliformes are widely distributed throughout the world and economically important to humans as domesticated animals or gamebirds. They are at a unique position for advancing knowledge and techniques of wi...Background: Galliformes are widely distributed throughout the world and economically important to humans as domesticated animals or gamebirds. They are at a unique position for advancing knowledge and techniques of wildlife conservation as the barometer of the status of applied ecology. Populations of many galliform species have declined mainly due to habitat loss and over-hunting. An assessment of knowledge of Galliformes could help to provide guidelines for future research and conservation strategies.Methods: Using the Web of Science search engine, we conducted a literature review of galliform-related articles published from 1990 to 2016. We used the "research area" option to filter articles focused on the zoology, environmental sciences ecology, biodiversity conservation, forestry, behavioral sciences, reproductive biology, biochemistry and molecular biology, cell biology, genetics and heredity, evolutionary biology, physiology and developmental biology. We then checked duplication based on the title, abstract and full text. In addition, we examined the reference lists of selected studies to include the publications that were missed by above searching.Results: We retained 1874 articles related to the Galliformes from the initial 243,128 publications that were found. About 91.4% focused on one or two species, and 85.0% were conducted within a short duration, typically 1–2 years. The majority of the articles concentrated on macroscopic ecology(55.5%), mainly focusing on habitat selection or habitat use. With recent advances of molecular biology, the studies of taxonomy and phylogenetics rose quickly in last two decades. The study of physiology and biochemistry was no longer limited to simple description but expanded to the mechanisms of phenotype and micro-evolutionary potential. An additional area receiving increasing attention is the conservation of Galliformes, with the assessment of the conservation status and conservation management effectiveness of Galliformes(e.g. species diversity and genetic diversity) becoming the focus.Conclusions: The studies on Galliformes have made great achievements since 1990, but there are still gaps, particularly in macroscopic ecology, molecular genetics, and conservation. There is an urgent need to enhance long-term monitoring and analysis of population dynamics, and applying different disciplines to galliform conservation. Moreover, life history information of many galliform species is still lacking, which has hindered conservation efforts and effectiveness. In addition, multidiscipline studies and new technologies are not common for galliform studies, and should be encouraged.展开更多
Population genomic data could provide valuable information for conservation efforts;however,limited studies have been conducted to investigate the genetic status of threatened pheasants.Reeves’s Pheasant(Syrmaticus r...Population genomic data could provide valuable information for conservation efforts;however,limited studies have been conducted to investigate the genetic status of threatened pheasants.Reeves’s Pheasant(Syrmaticus reevesii)is facing population decline,attributed to increases in habitat loss.There is a knowledge gap in understanding the genomic status and genetic basis underlying the local adaptation of this threatened bird.Here,we used population genomic data to assess population structure,genetic diversity,inbreeding patterns,and genetic divergence.Furthermore,we identified candidate genes linked with adaptation across the current distribution of Reeves’s Pheasant.The present study assembled the first de novo genome sequence of Reeves’s Pheasant and annotated 19,458 genes.We also sequenced 30 individuals from three populations(Dabie Mountain,Shennongjia,Qinling Mountain)and found that there was clear population structure among those populations.By comparing with other threatened species,we found that Reeves’s Pheasants have low genetic diversity.Runs of homozygosity suggest that the Shennongjia population has experienced serious inbreeding.The demographic history results indicated that three populations experienced several declines during the glacial period.Local adaptative analysis among the populations identified 241 candidate genes under directional selection.They are involved in a large variety of processes,including the immune response and pigmentation.Our results suggest that the three populations should be considered as three different conservation units.The current study provides genetic evidence for conserving the threatened Reeves’s Pheasant and provides genomic resources for global biodiversity management.展开更多
Large numbers of rotifer eggs from sediment resting egg banks may hatch simultaneously under appropriate conditions;therefore,natural populations are likely to be multiclonal in a growing season.A recent field investi...Large numbers of rotifer eggs from sediment resting egg banks may hatch simultaneously under appropriate conditions;therefore,natural populations are likely to be multiclonal in a growing season.A recent field investigation showed that subordinate and ephemeral clones were able to establish populations in an environment with several strongly dominant clone populations.However,it was not clear how the subordinate populations maintained their growth under these conditions where the crowding signal would induce high levels of sexual reproduction in the dominant clone populations.In the present study,we conducted a continuous passage to 60 generations for new populations at three different temperatures(15°C,25°C,and 35°C).These populations emerged from resting eggs produced by a clone population.At the first,30th,and 60th generations,the populations were sampled and fitness was assayed using the life-table method.We found a significant short-term fitness advantage for populations newly emerged from resting eggs produced by a clone population of the rotifer Brachionus calyciflorus,followed by a significant decrease in relative fitness with long-term continuous passage.Our results suggested that the early shortterm fitness advantage was important for later-hatched and subordinate clone populations in an environment with multiple sympatric clones.The early short-term fitness might also promote the coexistence of sympatric clones because it could help to offset the cost of early sexual reproduction.展开更多
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,i...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.展开更多
Background: China is one of the countries with abundant waterbird diversity. Over the past decades, China's waterbirds have suffered increasing threats from direct and indirect human activities. It is important to...Background: China is one of the countries with abundant waterbird diversity. Over the past decades, China's waterbirds have suffered increasing threats from direct and indirect human activities. It is important to clarify the population trends of and threats to waterbirds as well as to put forward conservation recommendations.Methods: We collected data of population trends of a total of 260 waterbird species in China from Wetlands International database. We calculated the number of species with increasing, declining, stable, and unknown trends. We collected threatened levels of waterbirds from the Red List of China's Vertebrates(2016), which was compiled according to the IUCN criteria of threatened species. Based on literature review, we refined the major threats to the threatened waterbird species in China.Results: Of the total 260 waterbird species in China, 84 species(32.3%) exhibited declining, 35 species(13.5%) kept stable, and 16 species(6.2%) showed increasing trends. Population trends were unknown for 125 species(48.1%). There was no significant difference in population trends between the migratory(32.4% decline) and resident(31.8% decline) species or among waterbirds distributed exclusively along coasts(28.6% decline), inland(36.6% decline), and both coasts and inland(32.5% decline). A total of 38 species(15.1% of the total) were listed as threatened species and 27 species(10.8% of the total) Near Threatened species. Habitat loss was the major threat to waterbirds, with 32 of the total 38(84.2%) threatened species being affected. In addition, 73.7%(28 species), 71.1%(27 species), and 57.9%(22 species) of the threatened species were affected by human disturbance, environmental pollution, and illegal hunting, respectively.Conclusions: We propose recommendations for waterbird conservation, including(1) strengthening conservation of nature wetlands and restoration of degraded wetlands,(2) enhancing public awareness on waterbird conservation,(3) improving the enforcement of Wildlife Protection Law and cracking down on illegal hunting,(4) carrying out longterm waterbird surveys to clarify population dynamics,(5) restoring populations of highly-threatened species through artificial intervention, and(6) promoting international and regional exchanges and cooperation to share information in waterbirds and their conservation.展开更多
Aerial parts of Xanthium italicum in an air tight container greatly inhibited root elongation of radish,implying that this invasive plant could release biologically active volatile organic compounds(VOCs)into the envi...Aerial parts of Xanthium italicum in an air tight container greatly inhibited root elongation of radish,implying that this invasive plant could release biologically active volatile organic compounds(VOCs)into the environment to affect other plants' growth.This phenomenon was further studied by evaluating the phytotoxic effects of X.italicum essential oil against two dicot plants,amaranth(Amaranthus mangostanus L.)and lettuce(Lectuca sativa L.),and two monocot plants,wheat(Triticum aestivum Linn)and ryegrass(Lolium multiforum),and analyzing the chemical composition of the oil.Among the 4 test species,amaranth was the most sensitive plant,0.5μl/mL essential oil application resulted in a 50% reduction on root elongation,and 2.5 μl/mL essential oil almost completely inhibited its seedling growth.Wheat was the least sensitive species,whose root growth was reduced to 36% of control by 5 μl/mL essential oil.The essential oil exerted moderate inhibitory effect on both lettuce and ryegrass.Compared to a commercial herbicide-Harness,X.italicum oil exhibited stronger phytotoxicity on amaranth,lettuce and wheat,but weaker activity on ryegrass.The chemical composition of the essential oil isolated by hydrodistillation from the aerial parts of X.italicum Moretti was analyzed by GC/MS.Thirty two compounds were identified,representing 94.89% of total oil,which was found to be rich in monoterpene hydrocarbons(60.71%).The main constituents of the oil were limonene(51.61%),germacrene B(6.98%),δ-cadinol(5.94%),β-pinene(5.23%),α-caryophyllene(5.1%)and bornyl acetate(3.15%).Bioassay revealed the dominant constituent-limonene,was unlikely the responsible phytotoxic compound due to its low biological activity;rather,there might be other oil constituent(s)that either act alone,or work together,and possibly assisted by synergistic effect,to display the phytotoxic activity.Our results suggested that X.italicum might produce allelopathic VOCs to facilitate its invasion success.This is the first report on the phytotoxic activity and the chemical composition of the essential oil of X.italicum Moretti from China.展开更多
Functional zones in cities constitute the most conspicuous components of newly developed urban areas, and have been a hot spot for domestic and foreign investors in China, which not only show the expanse of urban spac...Functional zones in cities constitute the most conspicuous components of newly developed urban areas, and have been a hot spot for domestic and foreign investors in China, which not only show the expanse of urban space accompanied by the shifts both in landscape (from rural to urban) and land use(from less extensive to extensive), but also display the transformation of regional ecological functions. By using the theories and methods of landscape ecology, the structure of landscapes and landscape ecological planning can be analyzed and evaluated for studying the urban functional zones’ layout. In 1990, the Central Government of China declared to develop and open up Pudong New Area so as to promote economic development in Shanghai. Benefited from the advantages of Shanghai’s location and economy, the government of Pudong New Area has successively built up 7 different functional zones over the past decade according to their functions and strategic goals. Based on the multi-spectral satellite imageries taken in 1990, 1997 and 2000, a landscape ecology analysis was carried out for Pudong New Area of Shanghai, supported by GIS technology. Green space (including croplands) and built-up areas are the major factors considered in developing urban landscape. This paper was mainly concerned with the different spatial patterns and dynamics of green space, built-up areas and new buildings in different functional zones, as influenced by different functional layouts and development strategies. The rapid urbanization in Pudong New Area resulted in a more homogeneous landscape. Agricultural landscape and suburban landscape were gradually replaced by urban landscape as the degree of urbanization increased. As a consequence of urbanization in Pudong, not only built-up patches, but also newly-built patches and green patches merged into one large patch, which should be attributed to the construction policy of extensive green space as the urban development process in Pudong New Area. The shape of green area of 7 functional zones became more and more regular because of the horticultural needs in Shanghai urban planning. Some suggestions were finally made for the study of future urban planning and layout.展开更多
Background: The Emei Shan Liocichla(Liocichla omeiensis) is a globally vulnerable babbler, endemic to southwestern China. We investigated its nest predators, nest-site selection and nest success at the Laojunshan Nati...Background: The Emei Shan Liocichla(Liocichla omeiensis) is a globally vulnerable babbler, endemic to southwestern China. We investigated its nest predators, nest-site selection and nest success at the Laojunshan National Nature Reserve in Sichuan, China in order to identify the precise nesting-habitat requirements of the species, and to test whether the nest-site-selection cues, preferred by the Emei Shan Liocichla, are positively associated with nest success.Methods: We used infrared cameras to determine nest predators. We compared the microhabitat attributes between nest and random sites, as well as successful and failed nests. We used Binary Logistic Regression to determine the most important variables affecting nest-site selection of the Emei Shan Liocichla. We used the nest survival analysis in Program MARK to estimate daily nest survival rates(DSR). Nest success was calculated using the Mayfield method.Results: In total 56 nests were found. The DSR for all nests that contained at least one egg was 0.9564 ± 0.0091(95 % CI 0.9346–0.9711)(n = 40), while the total nest success was 27.5 %. We identified four categories of predators in 10 nest predation events, i.e. squirrels(n = 5), snakes(n = 3), raptors(n = 1) and wasps(n = 1). We found that:(1) nest predation was the primary reason for nest failure of the Emei Shan Liocichla,(2) tree cover, bamboo cover, liana abundance and distance to forest edge or gap were the most important variables affecting nest-site selection of this species, and(3) the nest-site-selection variables we measured appeared not to be positively associated with nest success.Conclusions: Our findings suggest that the Emei Shan Liocichla tended to select nest sites near forest edges or gaps with good concealment and that nest-site selection by this species was nonrandom but not necessarily adaptive. Reducing forest-edge development and protecting bamboo stands should be effective for conservation of this species.展开更多
Background: The Russet Bush Warbler Locustella(previously Bradypterus) mandelli complex occurs in mountains in the eastern Himalayas, southern China, Vietnam, the Philippines, and Indonesia. The taxonomy has been deba...Background: The Russet Bush Warbler Locustella(previously Bradypterus) mandelli complex occurs in mountains in the eastern Himalayas, southern China, Vietnam, the Philippines, and Indonesia. The taxonomy has been debated,with one(L. seebohmi) to four(L. seebohmi, L. mandelli, L. montis and L. timorensis) species having been recognised.Methods: We used an integrative approach, incorporating analyses of morphology, vocalizations and a molecular marker, to re-evaluate species limits in the L. mandelli complex.Results: We found that central Chinese L. mandelli differed from those from India through northern Southeast Asia to southeast China in plumage, morphometrics and song. All were easily classified by song, and(wing + culmen)/tail ratio overlapped only marginally. Both groups were reciprocally monophyletic in a mitochondrial cytochrome b(cytb) gene tree, with a mean divergence of 1.0 ± 0.2%. They were sympatric and mostly altitudinally segregated in the breeding season in southern Sichuan province. We found that the Mt Victoria(western Myanmar) population differed vocally from other L. mandelli, but no specimens are available. Taiwan Bush Warbler L. alishanensis was sister to the L. mandelli complex, with the most divergent song. Plumage, vocal and cytb evidence supported the distinctness of the south Vietnamese L. mandelli idonea. The Timor Bush Warbler L. timorensis, Javan Bush Warbler L.montis and Benguet Bush Warbler L. seebohmi differed distinctly in plumage, but among-population song variation in L. montis exceeded the differences between some populations of these taxa, and mean pairwise cytb divergences were only 0.5–0.9%. We also found that some L. montis populations differed morphologically.Conclusions: We conclude that the central Chinese population of Russet Bush Warbler represents a new species,which we describe herein, breeding at mid elevations in Sichuan, Shaanxi, Hubei, Hunan and Guizhou provinces.The taxonomic status of the other allopatric populations is less clear. However, as they differ to a degree comparable with that of the sympatric L. mandelli and the new species, we elevate L. idonea to species status, and retain L. seebohmi and L. montis as separate species, the latter with timorensis as a subspecies. Further research should focus on different populations of L. montis and the Mt Victoria population of L. mandelli.展开更多
The energy budget and regulating factors were investigated over an estuarine wetland during one year of continuous measurement in 2006.The results show that the seasonal changes of the energy fluxes and Bowen ratio(β...The energy budget and regulating factors were investigated over an estuarine wetland during one year of continuous measurement in 2006.The results show that the seasonal changes of the energy fluxes and Bowen ratio(β) were greatly affected by incoming shortwave radiation and canopy growth.During the non-growing season and early-growing season, sensible heat(H) dominated the energy flux, and β could reach a maximum of 2.5, while during most of the growing season, latent heat dominated the energy flux and β fluctuated from 0.4 to 1.0.The energy budget ratio in growing season was about 0.76, and the value would be higher if heat exchange during tidal flooding was in-cluded.During tidal flooding days, β was slightly higher than that at exposure days in most cases.Vegetation cover seems exert little effect on energy partitioning except in March when the standing dead grass intercepted the incoming radiation that might reach the soil surface and reduce the turbulence between soil and atmosphere, thus suppressing the evaporation from the soil though the soil mositure was high at that time.展开更多
Background:Conserving migratory birds is challenging due to their reliance on multiple distant sites at different stages of their annual life cycle.The concept of“flyway”,which refers to all areas covered by the bre...Background:Conserving migratory birds is challenging due to their reliance on multiple distant sites at different stages of their annual life cycle.The concept of“flyway”,which refers to all areas covered by the breeding,nonbreeding,and migrating of birds,provides a framework for international cooperation for conservation.In the same flyway,however,the migratory activities of the same species can differ substantially between seasons and populations.Clarifying the seasonal and population differences in migration is helpful for understanding migration ecology and for identifying conservation gaps.Methods:Using satellite‑tracking we tracked the migration of Whimbrels(Numenius phaeopus variegatus)from nonbreeding sites at Moreton Bay(MB)and Roebuck Bay(RB)in Australia in the East Asian-Australasian Flyway.Mantel tests were used to analyze the strength of migration connectivity between the nonbreeding and breeding sites of MB and RB populations.Welch’s t test was used to compare the migration activities between the two populations and between northward and southward migration.Results:During northward migration,migration distance and duration were longer for the MB population than for the RB population.The distance and duration of the first leg flight during northward migration were longer for the MB population than for the RB population,suggesting that MB individuals deposited more fuel before departing from nonbreeding sites to support their longer nonstop flight.The RB population exhibited weaker migration connectivity(breeding sites dispersing over a range of 60 longitudes)than the MB population(breeding sites concentrating in a range of 5 longitudes in Far Eastern Russia).Compared with MB population,RB population was more dependent on the stopover sites in the Yellow Sea and the coastal regions in China,where tidal habitat has suffered dramatic loss.However,RB population increased while MB population decreased over the past decades,suggesting that loss of tidal habitat at stopover sites had less impact on the Whimbrel populations,which can use diverse habitat types.Different trends between the populations might be due to the different degrees of hunting pressure in their breeding grounds.Conclusions:This study highlights that conservation measures can be improved by understanding the full annual life cycle of movements of multiple populations of Whimbrels and probably other migratory birds.展开更多
Interspecific killing is a primary reason for the low survival rates of some animal species. The giant panda(Ailuropoda melanoleuca) is an altricial eutherian mammal and thus, in comparison to other infants, panda cub...Interspecific killing is a primary reason for the low survival rates of some animal species. The giant panda(Ailuropoda melanoleuca) is an altricial eutherian mammal and thus, in comparison to other infants, panda cubs are highly vulnerable, which may significantly influence the selection of breeding sites by females. Here, we used infrared camera traps to monitor giant panda dens for 5.5 years in Foping National Nature Reserve(FNNR) to determine how interspecific factors affect den selection by wild female pandas. Results indicated that Asian black bears(Ursus thibetanus), yellow-throated martens(Martes flavigula), leopard cats(Prionailurus bengalensis), and masked palm civets(Paguma larvata) visited the dens frequently, and the presence of these species negatively influenced den selection by female pandas. Interestingly, the presence of rodents and terrestrial birds appeared to indicate den safety, and female giant pandas were not averse and even preferred dens with a high abundance index of rodents and terrestrial birds. The den suitability index(DSI) was a reliable tool for evaluating whether dens were suitable for female giant pandas to give birth to and rear cubs, with preference for dens with high DSI values. This study increases our understanding of the den selection criteria of female giant pandas and the main threats to the survival of their cubs,thus providing important guidance for the conservation and management of this species.展开更多
Background:The uropygial gland is an exocrine gland located above the tail of birds that produces a diverse range of biochemicals.It has been hypothesized to be involved in chemical protection,water-proofing and maint...Background:The uropygial gland is an exocrine gland located above the tail of birds that produces a diverse range of biochemicals.It has been hypothesized to be involved in chemical protection,water-proofing and maintenance of plumage brightness.Although these not necessarily mutually exclusive functions have received some empirical support,there has been little empirical research on the function of water-proofing.Methods:Here we analyzed data for 229 individual eiders(Somateria mollissima)collected by Danish hunters during 2016-2018.Results:The Eider is a sea-duck that spends almost its entire life in sea water emphasizing water-proofing of the plumage.The size of the uropygial gland increased with body mass in males,but not in females,and it increased with age.The size of the uropygial gland decreased during winter. Eiders with small uropygial glands grew their feathers at a fast rate.Eiders with large wing areas had large uropygial glands. Conclusions:These findings are consistent with large uropygial glands playing a role in water-proofing during molt and foraging, but also that uropygial glands may play a role in chemical defense.展开更多
基金supported by the National Natural Science Foundation of China(32301453 and 3272675)the China Postdoctoral Science Foundation(2023M730682)。
文摘Achieving high maize yields and efficient phosphorus(P)use with limited environmental impacts is one of the greatest challenges in sustainable maize production.Increasing plant density is considered an effective approach for achieving high maize yields.However,the low mobility of P in soils and the scarcity of natural P resources have hindered the development of methods that can simultaneously optimize P use and mitigate the P-related environmental footprint at high plant densities.In this study,meta-analysis and substance flow analysis were conducted to evaluate the effects of different types of mineral P fertilizer on maize yield at varying plant densities and assess the flow of P from rock phosphate mining to P fertilizer use for maize production in China.A significantly higher yield was obtained at higher plant densities than at lower plant densities.The application of single superphosphate,triple super-phosphate,and calcium magnesium phosphate at high plant densities resulted in higher yields and a smaller environmental footprint than the application of diammonium phosphate and monoammonium phosphate.Our scenario analyses suggest that combining the optimal P type and application rate with a high plant density could increase maize yield by 22%.Further,the P resource use efficiency throughout the P supply chain increased by 39%,whereas the P-related environmental footprint decreased by 33%.Thus,simultaneously optimizing the P type and application rate at high plant densities achieved multiple objectives during maize production,indicating that combining P management with cropping techniques is a practical approach to sustainable maize production.These findings offer strategic,synergistic options for achieving sustainable agricultural development.
基金supported by the National Natural Science Foundation of China(T2350005 to YL)。
文摘Understanding the foraging behavior is essential for investigating seabird ecology and conservation,as well as monitoring the well-being of the marine environment.Breeding seabirds adopt diverse foraging strategies to maximize energy gains and cope with the intensified challenges of parenting and self-maintenance.Such tradeoff may stem from the heterogeneity of food resources and the constraints of central place foraging.Nevertheless,abundant marine productivity could alleviate the energy limitation for seabirds,resulting in a consistent foraging approach.Here,we investigated the foraging strategy during the breeding season of a cryptic small-sized seabird,Swinhoe’s Storm-petrel(Hydrobates monorhis),in the Yellow Sea,a productive marginal sea of the Northwest Pacific.Using GPS tracking,we evaluated habitat preference,quantified the foraging strategy,and tested if environmental conditions and individual traits influence foraging trips.We found that Swinhoe’s Storm-petrels preferred nearshore areas with shallow water and engaged in primarily short foraging trips.Distinctive southeastward and southwestward strategies emerged when combining trip metrics,including foraging direction,duration,and maximum distance.The bathymetry,proximity to the coastline,and sea surface temperature differed in two foraging strategies.Foraging strategies exhibited flexibility between individuals,potentially explained by wing morphology,in which longer-winged birds are more likely to embark on longer-distance foraging trips.These findings highlight the impact of environmental factors and individual traits on seabirds’foraging decisions in productive marginal sea ecosystems.Our study also provides valuable insights into the foraging ecology of this Asian endemic storm-petrel.
基金supported by the National Natural Science Foundation of China(31770225)the Henan Science and Technology Project(202102110077)the Henan Agricultural University Science&Technology Innovation Fund(KJCX2016A2).
文摘Understanding the genetic basis underlying the local adaptation of nonmodel species is a fundamental goal in evolutionary biology.In this study,we explored the genetic mechanisms of the local adaptation of Forsythia suspensa using genome sequence and population genomics data obtained from specific-locus amplified fragment sequencing.We assembled a high-quality reference genome of weeping forsythia(Scaffold N50=7.3 Mb)using ultralong Nanopore reads.Then,genome-wide comparative analysis was performed for 15 natural populations of weeping forsythia across its current distribution range.Our results revealed that candidate genes associated with local adaptation are functionally correlated with solar radiation,temperature and water variables across heterogeneous environmental scenarios.In particular,solar radiation during the period of fruit development and seed drying after ripening,cold,and drought significantly contributed to the adaptive differentiation of F.suspensa.Natural selection exerted by environmental factors contributed substantially to the population genetic structure of F.suspensa.Our results supported the hypothesis that adaptive differentiation should be highly pronounced in the genes involved in signal crosstalk between different environmental variables.Our population genomics study of F.suspensa provides insights into the fundamental genetic mechanisms of the local adaptation of plant species to climatic gradients.
基金the Science and Technology Projects in Guangzhou(202102020231)YL was funded by the Forestry Administration of Guangdong Province,China(DFGP Project of Fauna of Guangdong202115 and Science and Technology Planning Projects of Guangdong Province-2021B1212110002).
文摘Reproduction investment is a prominent trade-off in life-history theory and is subject to strong selection pressure.The avian eggshell,as a crucial barrier between the bird embryo and the surrounding environment,undergoes optimization under different environmental selection regimes to ensure the successful development of embryos,which can be linked to local adaptation.Therefore,understanding the variation in eggshell microstructure and composition in wild bird populations living in contrasting ambient environments is of great significance.In this study,we utilized electron microscope ultrastructure measurement and elemental analyses to measure and compare the microstructure and element composition of eggshells from three wild plover populations(Charadrius alexandrinus and C.dealbatus)residing in heterogeneous habitats across varied climatic zones.These populations include the high-altitude Qinghai Lake population,the temperate coastal Tangshan population,and the tropical coastal Zhanjiang population.Our findings revealed that the palisade layer was thinner in the Qinghai Lake population compared to its lowland populations.This difference might be attributed to hypoxia which facilitates the hatching process by allowing chicks to easily break through their shells.Additionally,the variations in the elemental composition of the eggshells among populations well reflected the distribution of element content in different geographical regions.The Qinghai Lake population displayed low zinc and low manganese levels but high calcium levels,while the Zhanjiang population exhibited high zinc,high iron,high manganese,and high phosphorus levels.Furthermore,these variations in elemental composition could also account for the observed microstructural differences among populations.Collectively,we propose that the dissimilarities in eggshell microstructure and elemental composition among populations could be attributed to adaptations to different environmental conditions.Our findings lay the groundwork for future research to explore the mechanisms behind the variations in eggshell characteristics among wild bird populations,and contribute to a broader understanding of biodiversity mechanisms.
基金financially supported by National Key Research and Development Program of China (2022YFF1301004)the National Natural Science Foundation of China (31830089 and 32170518)TP’s work in the East Asian-Australasian Flyway through Global Flyway Network was supported by WWF-Netherlands,the MAVA Foundation and many other benefactors
文摘China’s coastal wetlands provide breeding,migration stopover,and wintering habitats for about 230 waterbird species,which is more than a quarter of all waterbirds in the world.Large-scale and high intensity human activities have resulted in serious loss and degradation of coastal wetlands over the past half century,causing population declines in many waterbirds.Through a literature review and expert surveys,this article reviews conservation measures taken in recent decades to protect waterbirds in China’s coastal wetlands and provides recommendations for future conservation action from three aspects:policy and administration,habitat conservation and management,and multiparty participation.Over the past decades,many conservation legislation,regulations and action plans at the national level and more site-specific measures and interventions have been implemented,with notable improvement in the effectiveness in policy making and multi-stakeholder participation.Accordingly,some threats to waterbirds have been mitigated and many key sites for waterbirds have been designated as strictly protected nature reserves.However,some critical issues still remain,mostly related to habitat conservation and management,such as coastal wetland restoration,control of invasive Spartina alterniflora,control of environmental pollution,and improvement of artificial habitat quality.We highlight that protecting natural tidal wetlands and improving habitat quality are critical for the conservation of coastal waterbirds,especially those highly dependent on the intertidal wetlands.China has demonstrated strong commitment to ecological conservation and restoration for the future,in terms of both funding and policies for biodiversity and wetland ecosystems.It is important that this commitment to conserve coastal waterbirds is supported continuously by science-and evidence-based decisions and actions.
基金supported by the funded by the National Key Programme of Research and 422 Development,Ministry of Science and Technology(2016YFC0503200)
文摘Background: Galliformes are widely distributed throughout the world and economically important to humans as domesticated animals or gamebirds. They are at a unique position for advancing knowledge and techniques of wildlife conservation as the barometer of the status of applied ecology. Populations of many galliform species have declined mainly due to habitat loss and over-hunting. An assessment of knowledge of Galliformes could help to provide guidelines for future research and conservation strategies.Methods: Using the Web of Science search engine, we conducted a literature review of galliform-related articles published from 1990 to 2016. We used the "research area" option to filter articles focused on the zoology, environmental sciences ecology, biodiversity conservation, forestry, behavioral sciences, reproductive biology, biochemistry and molecular biology, cell biology, genetics and heredity, evolutionary biology, physiology and developmental biology. We then checked duplication based on the title, abstract and full text. In addition, we examined the reference lists of selected studies to include the publications that were missed by above searching.Results: We retained 1874 articles related to the Galliformes from the initial 243,128 publications that were found. About 91.4% focused on one or two species, and 85.0% were conducted within a short duration, typically 1–2 years. The majority of the articles concentrated on macroscopic ecology(55.5%), mainly focusing on habitat selection or habitat use. With recent advances of molecular biology, the studies of taxonomy and phylogenetics rose quickly in last two decades. The study of physiology and biochemistry was no longer limited to simple description but expanded to the mechanisms of phenotype and micro-evolutionary potential. An additional area receiving increasing attention is the conservation of Galliformes, with the assessment of the conservation status and conservation management effectiveness of Galliformes(e.g. species diversity and genetic diversity) becoming the focus.Conclusions: The studies on Galliformes have made great achievements since 1990, but there are still gaps, particularly in macroscopic ecology, molecular genetics, and conservation. There is an urgent need to enhance long-term monitoring and analysis of population dynamics, and applying different disciplines to galliform conservation. Moreover, life history information of many galliform species is still lacking, which has hindered conservation efforts and effectiveness. In addition, multidiscipline studies and new technologies are not common for galliform studies, and should be encouraged.
基金supported by the Biodiversity Survey,Monitoring and Assessment Project(2019–2023)of the Ministry of Ecology and EnvironmentChina(No.2019HB2096001006 to ZZ)+2 种基金the National Natural Science Foundation of China(31672319)Endangered Species Scientific Commission of China(No.2022–331)supported by the China Scholarship Council,China。
文摘Population genomic data could provide valuable information for conservation efforts;however,limited studies have been conducted to investigate the genetic status of threatened pheasants.Reeves’s Pheasant(Syrmaticus reevesii)is facing population decline,attributed to increases in habitat loss.There is a knowledge gap in understanding the genomic status and genetic basis underlying the local adaptation of this threatened bird.Here,we used population genomic data to assess population structure,genetic diversity,inbreeding patterns,and genetic divergence.Furthermore,we identified candidate genes linked with adaptation across the current distribution of Reeves’s Pheasant.The present study assembled the first de novo genome sequence of Reeves’s Pheasant and annotated 19,458 genes.We also sequenced 30 individuals from three populations(Dabie Mountain,Shennongjia,Qinling Mountain)and found that there was clear population structure among those populations.By comparing with other threatened species,we found that Reeves’s Pheasants have low genetic diversity.Runs of homozygosity suggest that the Shennongjia population has experienced serious inbreeding.The demographic history results indicated that three populations experienced several declines during the glacial period.Local adaptative analysis among the populations identified 241 candidate genes under directional selection.They are involved in a large variety of processes,including the immune response and pigmentation.Our results suggest that the three populations should be considered as three different conservation units.The current study provides genetic evidence for conserving the threatened Reeves’s Pheasant and provides genomic resources for global biodiversity management.
基金Supported by the National Natural Science Foundation of China(Nos.30970349,41206110)
文摘Large numbers of rotifer eggs from sediment resting egg banks may hatch simultaneously under appropriate conditions;therefore,natural populations are likely to be multiclonal in a growing season.A recent field investigation showed that subordinate and ephemeral clones were able to establish populations in an environment with several strongly dominant clone populations.However,it was not clear how the subordinate populations maintained their growth under these conditions where the crowding signal would induce high levels of sexual reproduction in the dominant clone populations.In the present study,we conducted a continuous passage to 60 generations for new populations at three different temperatures(15°C,25°C,and 35°C).These populations emerged from resting eggs produced by a clone population.At the first,30th,and 60th generations,the populations were sampled and fitness was assayed using the life-table method.We found a significant short-term fitness advantage for populations newly emerged from resting eggs produced by a clone population of the rotifer Brachionus calyciflorus,followed by a significant decrease in relative fitness with long-term continuous passage.Our results suggested that the early shortterm fitness advantage was important for later-hatched and subordinate clone populations in an environment with multiple sympatric clones.The early short-term fitness might also promote the coexistence of sympatric clones because it could help to offset the cost of early sexual reproduction.
基金supported by the National Key Research and Development Program of China (No. 2019YFA0607103)Program of National Forestry and Grassland Administration (No.213023721203)
文摘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.
基金Project supported by the National Natural Science Foundation of China (Nos.30370235 and 30670330)Science and Technology Commission of Shanghai (No.04DZ19304)Ministry of Education of China (No.105063)
基金financially supported by the National Natural Science Foundation of China(Grant Nos.31572280 and 31071939)
文摘Background: China is one of the countries with abundant waterbird diversity. Over the past decades, China's waterbirds have suffered increasing threats from direct and indirect human activities. It is important to clarify the population trends of and threats to waterbirds as well as to put forward conservation recommendations.Methods: We collected data of population trends of a total of 260 waterbird species in China from Wetlands International database. We calculated the number of species with increasing, declining, stable, and unknown trends. We collected threatened levels of waterbirds from the Red List of China's Vertebrates(2016), which was compiled according to the IUCN criteria of threatened species. Based on literature review, we refined the major threats to the threatened waterbird species in China.Results: Of the total 260 waterbird species in China, 84 species(32.3%) exhibited declining, 35 species(13.5%) kept stable, and 16 species(6.2%) showed increasing trends. Population trends were unknown for 125 species(48.1%). There was no significant difference in population trends between the migratory(32.4% decline) and resident(31.8% decline) species or among waterbirds distributed exclusively along coasts(28.6% decline), inland(36.6% decline), and both coasts and inland(32.5% decline). A total of 38 species(15.1% of the total) were listed as threatened species and 27 species(10.8% of the total) Near Threatened species. Habitat loss was the major threat to waterbirds, with 32 of the total 38(84.2%) threatened species being affected. In addition, 73.7%(28 species), 71.1%(27 species), and 57.9%(22 species) of the threatened species were affected by human disturbance, environmental pollution, and illegal hunting, respectively.Conclusions: We propose recommendations for waterbird conservation, including(1) strengthening conservation of nature wetlands and restoration of degraded wetlands,(2) enhancing public awareness on waterbird conservation,(3) improving the enforcement of Wildlife Protection Law and cracking down on illegal hunting,(4) carrying out longterm waterbird surveys to clarify population dynamics,(5) restoring populations of highly-threatened species through artificial intervention, and(6) promoting international and regional exchanges and cooperation to share information in waterbirds and their conservation.
基金financially supported by the International Science and Technology Cooperation Program of China (2010 DFA 92720-06)the One Hundred Person Project of the Chinese Academy of Sciences granted to Chi ZHANGthe West Light Foundation of the Chinese Academy of Sciences granted to Hua SHAO (LHXZ201202)
文摘Aerial parts of Xanthium italicum in an air tight container greatly inhibited root elongation of radish,implying that this invasive plant could release biologically active volatile organic compounds(VOCs)into the environment to affect other plants' growth.This phenomenon was further studied by evaluating the phytotoxic effects of X.italicum essential oil against two dicot plants,amaranth(Amaranthus mangostanus L.)and lettuce(Lectuca sativa L.),and two monocot plants,wheat(Triticum aestivum Linn)and ryegrass(Lolium multiforum),and analyzing the chemical composition of the oil.Among the 4 test species,amaranth was the most sensitive plant,0.5μl/mL essential oil application resulted in a 50% reduction on root elongation,and 2.5 μl/mL essential oil almost completely inhibited its seedling growth.Wheat was the least sensitive species,whose root growth was reduced to 36% of control by 5 μl/mL essential oil.The essential oil exerted moderate inhibitory effect on both lettuce and ryegrass.Compared to a commercial herbicide-Harness,X.italicum oil exhibited stronger phytotoxicity on amaranth,lettuce and wheat,but weaker activity on ryegrass.The chemical composition of the essential oil isolated by hydrodistillation from the aerial parts of X.italicum Moretti was analyzed by GC/MS.Thirty two compounds were identified,representing 94.89% of total oil,which was found to be rich in monoterpene hydrocarbons(60.71%).The main constituents of the oil were limonene(51.61%),germacrene B(6.98%),δ-cadinol(5.94%),β-pinene(5.23%),α-caryophyllene(5.1%)and bornyl acetate(3.15%).Bioassay revealed the dominant constituent-limonene,was unlikely the responsible phytotoxic compound due to its low biological activity;rather,there might be other oil constituent(s)that either act alone,or work together,and possibly assisted by synergistic effect,to display the phytotoxic activity.Our results suggested that X.italicum might produce allelopathic VOCs to facilitate its invasion success.This is the first report on the phytotoxic activity and the chemical composition of the essential oil of X.italicum Moretti from China.
文摘Functional zones in cities constitute the most conspicuous components of newly developed urban areas, and have been a hot spot for domestic and foreign investors in China, which not only show the expanse of urban space accompanied by the shifts both in landscape (from rural to urban) and land use(from less extensive to extensive), but also display the transformation of regional ecological functions. By using the theories and methods of landscape ecology, the structure of landscapes and landscape ecological planning can be analyzed and evaluated for studying the urban functional zones’ layout. In 1990, the Central Government of China declared to develop and open up Pudong New Area so as to promote economic development in Shanghai. Benefited from the advantages of Shanghai’s location and economy, the government of Pudong New Area has successively built up 7 different functional zones over the past decade according to their functions and strategic goals. Based on the multi-spectral satellite imageries taken in 1990, 1997 and 2000, a landscape ecology analysis was carried out for Pudong New Area of Shanghai, supported by GIS technology. Green space (including croplands) and built-up areas are the major factors considered in developing urban landscape. This paper was mainly concerned with the different spatial patterns and dynamics of green space, built-up areas and new buildings in different functional zones, as influenced by different functional layouts and development strategies. The rapid urbanization in Pudong New Area resulted in a more homogeneous landscape. Agricultural landscape and suburban landscape were gradually replaced by urban landscape as the degree of urbanization increased. As a consequence of urbanization in Pudong, not only built-up patches, but also newly-built patches and green patches merged into one large patch, which should be attributed to the construction policy of extensive green space as the urban development process in Pudong New Area. The shape of green area of 7 functional zones became more and more regular because of the horticultural needs in Shanghai urban planning. Some suggestions were finally made for the study of future urban planning and layout.
基金supported by the National Natural Science Foundation of China(No.31272330)the Scientific Research Innovation Team Projects of Leshan Normal University
文摘Background: The Emei Shan Liocichla(Liocichla omeiensis) is a globally vulnerable babbler, endemic to southwestern China. We investigated its nest predators, nest-site selection and nest success at the Laojunshan National Nature Reserve in Sichuan, China in order to identify the precise nesting-habitat requirements of the species, and to test whether the nest-site-selection cues, preferred by the Emei Shan Liocichla, are positively associated with nest success.Methods: We used infrared cameras to determine nest predators. We compared the microhabitat attributes between nest and random sites, as well as successful and failed nests. We used Binary Logistic Regression to determine the most important variables affecting nest-site selection of the Emei Shan Liocichla. We used the nest survival analysis in Program MARK to estimate daily nest survival rates(DSR). Nest success was calculated using the Mayfield method.Results: In total 56 nests were found. The DSR for all nests that contained at least one egg was 0.9564 ± 0.0091(95 % CI 0.9346–0.9711)(n = 40), while the total nest success was 27.5 %. We identified four categories of predators in 10 nest predation events, i.e. squirrels(n = 5), snakes(n = 3), raptors(n = 1) and wasps(n = 1). We found that:(1) nest predation was the primary reason for nest failure of the Emei Shan Liocichla,(2) tree cover, bamboo cover, liana abundance and distance to forest edge or gap were the most important variables affecting nest-site selection of this species, and(3) the nest-site-selection variables we measured appeared not to be positively associated with nest success.Conclusions: Our findings suggest that the Emei Shan Liocichla tended to select nest sites near forest edges or gaps with good concealment and that nest-site selection by this species was nonrandom but not necessarily adaptive. Reducing forest-edge development and protecting bamboo stands should be effective for conservation of this species.
基金the Laojunshan Nature Reserve Management Bureau for providing support for field work(to B.D.,P.A.,Y.L.,P.R.and J.Z)the Chinese National Science and Technology Basic Work Program–The Comprehensive Scientific Survey of Biodiversity from Luoxiao range Region in China(2013FY111500)(to Y.L.and J.Z)+3 种基金Jornvall Foundation(to P.A.)the Sound Approach(to P.A.and U.O.)the Chinese Academy of Sciences Visiting Professorship for Senior International Scientists(No.2011T2S04,to P.A.)Swarovski Hong Kong Ltd.(to P.A.)
文摘Background: The Russet Bush Warbler Locustella(previously Bradypterus) mandelli complex occurs in mountains in the eastern Himalayas, southern China, Vietnam, the Philippines, and Indonesia. The taxonomy has been debated,with one(L. seebohmi) to four(L. seebohmi, L. mandelli, L. montis and L. timorensis) species having been recognised.Methods: We used an integrative approach, incorporating analyses of morphology, vocalizations and a molecular marker, to re-evaluate species limits in the L. mandelli complex.Results: We found that central Chinese L. mandelli differed from those from India through northern Southeast Asia to southeast China in plumage, morphometrics and song. All were easily classified by song, and(wing + culmen)/tail ratio overlapped only marginally. Both groups were reciprocally monophyletic in a mitochondrial cytochrome b(cytb) gene tree, with a mean divergence of 1.0 ± 0.2%. They were sympatric and mostly altitudinally segregated in the breeding season in southern Sichuan province. We found that the Mt Victoria(western Myanmar) population differed vocally from other L. mandelli, but no specimens are available. Taiwan Bush Warbler L. alishanensis was sister to the L. mandelli complex, with the most divergent song. Plumage, vocal and cytb evidence supported the distinctness of the south Vietnamese L. mandelli idonea. The Timor Bush Warbler L. timorensis, Javan Bush Warbler L.montis and Benguet Bush Warbler L. seebohmi differed distinctly in plumage, but among-population song variation in L. montis exceeded the differences between some populations of these taxa, and mean pairwise cytb divergences were only 0.5–0.9%. We also found that some L. montis populations differed morphologically.Conclusions: We conclude that the central Chinese population of Russet Bush Warbler represents a new species,which we describe herein, breeding at mid elevations in Sichuan, Shaanxi, Hubei, Hunan and Guizhou provinces.The taxonomic status of the other allopatric populations is less clear. However, as they differ to a degree comparable with that of the sympatric L. mandelli and the new species, we elevate L. idonea to species status, and retain L. seebohmi and L. montis as separate species, the latter with timorensis as a subspecies. Further research should focus on different populations of L. montis and the Mt Victoria population of L. mandelli.
基金Under the auspices of National Natural Science Foundation of China (No. 30870409,40471087)Science and Technology Commission of Shanghai (No. 07DZ12038-2)the Program for New Century Excellent Talents in University (No.NCET-06-0364) funded by the Ministry of Education of China
文摘The energy budget and regulating factors were investigated over an estuarine wetland during one year of continuous measurement in 2006.The results show that the seasonal changes of the energy fluxes and Bowen ratio(β) were greatly affected by incoming shortwave radiation and canopy growth.During the non-growing season and early-growing season, sensible heat(H) dominated the energy flux, and β could reach a maximum of 2.5, while during most of the growing season, latent heat dominated the energy flux and β fluctuated from 0.4 to 1.0.The energy budget ratio in growing season was about 0.76, and the value would be higher if heat exchange during tidal flooding was in-cluded.During tidal flooding days, β was slightly higher than that at exposure days in most cases.Vegetation cover seems exert little effect on energy partitioning except in March when the standing dead grass intercepted the incoming radiation that might reach the soil surface and reduce the turbulence between soil and atmosphere, thus suppressing the evaporation from the soil though the soil mositure was high at that time.
基金This study was financially supported by the National Key Research and Development Program of China(2018YFC1406402)the National Natural Science Foundation of China(31830089 and 31772467)World Wide Fund for Nature Beijing Office(10003881).
文摘Background:Conserving migratory birds is challenging due to their reliance on multiple distant sites at different stages of their annual life cycle.The concept of“flyway”,which refers to all areas covered by the breeding,nonbreeding,and migrating of birds,provides a framework for international cooperation for conservation.In the same flyway,however,the migratory activities of the same species can differ substantially between seasons and populations.Clarifying the seasonal and population differences in migration is helpful for understanding migration ecology and for identifying conservation gaps.Methods:Using satellite‑tracking we tracked the migration of Whimbrels(Numenius phaeopus variegatus)from nonbreeding sites at Moreton Bay(MB)and Roebuck Bay(RB)in Australia in the East Asian-Australasian Flyway.Mantel tests were used to analyze the strength of migration connectivity between the nonbreeding and breeding sites of MB and RB populations.Welch’s t test was used to compare the migration activities between the two populations and between northward and southward migration.Results:During northward migration,migration distance and duration were longer for the MB population than for the RB population.The distance and duration of the first leg flight during northward migration were longer for the MB population than for the RB population,suggesting that MB individuals deposited more fuel before departing from nonbreeding sites to support their longer nonstop flight.The RB population exhibited weaker migration connectivity(breeding sites dispersing over a range of 60 longitudes)than the MB population(breeding sites concentrating in a range of 5 longitudes in Far Eastern Russia).Compared with MB population,RB population was more dependent on the stopover sites in the Yellow Sea and the coastal regions in China,where tidal habitat has suffered dramatic loss.However,RB population increased while MB population decreased over the past decades,suggesting that loss of tidal habitat at stopover sites had less impact on the Whimbrel populations,which can use diverse habitat types.Different trends between the populations might be due to the different degrees of hunting pressure in their breeding grounds.Conclusions:This study highlights that conservation measures can be improved by understanding the full annual life cycle of movements of multiple populations of Whimbrels and probably other migratory birds.
基金the National Natural Science Foundation of China(31622012)Key Project of the Chinese Academy of Sciences(QYZDB-SSW-SMC047)。
文摘Interspecific killing is a primary reason for the low survival rates of some animal species. The giant panda(Ailuropoda melanoleuca) is an altricial eutherian mammal and thus, in comparison to other infants, panda cubs are highly vulnerable, which may significantly influence the selection of breeding sites by females. Here, we used infrared camera traps to monitor giant panda dens for 5.5 years in Foping National Nature Reserve(FNNR) to determine how interspecific factors affect den selection by wild female pandas. Results indicated that Asian black bears(Ursus thibetanus), yellow-throated martens(Martes flavigula), leopard cats(Prionailurus bengalensis), and masked palm civets(Paguma larvata) visited the dens frequently, and the presence of these species negatively influenced den selection by female pandas. Interestingly, the presence of rodents and terrestrial birds appeared to indicate den safety, and female giant pandas were not averse and even preferred dens with a high abundance index of rodents and terrestrial birds. The den suitability index(DSI) was a reliable tool for evaluating whether dens were suitable for female giant pandas to give birth to and rear cubs, with preference for dens with high DSI values. This study increases our understanding of the den selection criteria of female giant pandas and the main threats to the survival of their cubs,thus providing important guidance for the conservation and management of this species.
文摘Background:The uropygial gland is an exocrine gland located above the tail of birds that produces a diverse range of biochemicals.It has been hypothesized to be involved in chemical protection,water-proofing and maintenance of plumage brightness.Although these not necessarily mutually exclusive functions have received some empirical support,there has been little empirical research on the function of water-proofing.Methods:Here we analyzed data for 229 individual eiders(Somateria mollissima)collected by Danish hunters during 2016-2018.Results:The Eider is a sea-duck that spends almost its entire life in sea water emphasizing water-proofing of the plumage.The size of the uropygial gland increased with body mass in males,but not in females,and it increased with age.The size of the uropygial gland decreased during winter. Eiders with small uropygial glands grew their feathers at a fast rate.Eiders with large wing areas had large uropygial glands. Conclusions:These findings are consistent with large uropygial glands playing a role in water-proofing during molt and foraging, but also that uropygial glands may play a role in chemical defense.
