Environmental variations and ontogeny may affect plant morphological traits and biomass allocation patterns that are related to the adjustments of plant ecological strategies. We selected 2-, 3-and 4-year-old Fritilla...Environmental variations and ontogeny may affect plant morphological traits and biomass allocation patterns that are related to the adjustments of plant ecological strategies. We selected 2-, 3-and 4-year-old Fritillaria unibracteata plants to explore the ontogenetic and altitudinal changes that impact their morphological traits(i.e., plant height, single leaf area,and specific leaf area) and biomass allocations [i.e.,biomass allocations of roots, bulbs, leaves, stems, and flowers] at relatively low altitudinal ranges(3400 m to 3600 m asl) and high altitudinal ranges(3600 m to4000 m asl). Our results indicated that plant height,root biomass allocation, and stem biomass allocation significantly increased during the process of individual growth and development, but single leaf area, specific leaf area, bulb biomass allocation, and leaf biomass allocation showed opposite trends.Furthermore, the impacts of altitudinal changes on morphological traits and biomass allocations had no significant differences at low altitude, except for single leaf area of 2-year-old plants. At high altitude,significantly reduced plant height, single leaf area and leaf biomass allocation for the 2-year-old plants,specific leaf area for the 2-and 4-year-old plants, and stem biomass allocation were found along altitudinal gradients. Significantly increased sexual reproductive allocation and relatively stable single leaf area and leaf biomass allocation were also observed for the 3-and 4-year-old plants. In addition, stable specific leaf area for the 3-year-old plants and root biomass allocation were recorded. These results suggested that the adaptive adjustments of alpine plants, in particular F. unibracteata were simultaneously influenced by altitudinal gradients and ontogeny.展开更多
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...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.展开更多
Based on two bottom trawl surveys conducted in autumn 2000 and 2001,a total of 1106 stomach samples of Bombay duck Harpadon nehereus between 23–278 mm fork length were collected and analyzed.The results show that Bom...Based on two bottom trawl surveys conducted in autumn 2000 and 2001,a total of 1106 stomach samples of Bombay duck Harpadon nehereus between 23–278 mm fork length were collected and analyzed.The results show that Bombay duck prey items consisted of 11 groups or 32 species,of which Apogon lineatus,Leptochela gracilis,Acetes chinensis,and Euphausia pacifi ca were the dominant prey species.Ontogenetic variations were found in feeding habits and feeding activity of Bombay duck.Feeding activity was highest in fi sh smaller than 50 mm,lowest in fi sh between 50 and 99 mm,and then increased with increasing size thereafter.As Bombay duck size increased,fi sh prey increased in importance,whereas euphausiids and decapods decreased in importance.Different trophic guilds were observed in feeding habits across the examined size range.Bombay duck smaller than 50 mm were zooplanktivores,mainly feeding on zooplankton and fi sh larva;those between 50 and 149 mm were generalist predators,mainly feeding on pelagic shrimps,demersal shrimps and fi shes;and those larger than 150 mm were piscivores,mainly feeding on fi shes.展开更多
Investigating the effects of ontogenetic stage and leaf age on leaf traits is important for understanding the utilization and distribution of resources in the process of plant growth.However,few studies have been cond...Investigating the effects of ontogenetic stage and leaf age on leaf traits is important for understanding the utilization and distribution of resources in the process of plant growth.However,few studies have been conducted to show how traits and trait-trait relationships change across a range of ontogenetic stage and leaf age for evergreen coniferous species.We divided 67 Pinus koraiensis Sieb.et Zucc.of various sizes(0.3-100 cm diameter at breast height,DBH)into four ontogenetic stages,i.e.,young trees,middle-aged trees,mature trees and over-mature trees,and measured the leaf mass per area(LMA),leaf dry matter content(LDMC),and mass-based leaf nitrogen content(N)and phosphorus content(P)of each leaf age group for each sampled tree.One-way analysis of variance(ANOVA)was used to describe the variation in leaf traits by ontogenetic stage and leaf age.The standardized major axis method was used to explore the effects of ontogenetic stage and leaf age on trait-trait relationships.We found that LMA and LDMC increased significantly and N and P decreased significantly with increases in the ontogenetic stage and leaf age.Most trait-trait relationships were consistent with the leaf economic spectrum(LES)at a global scale.Among them,leaf N content and LDMC showed a significant negative correlation,leaf N and P contents showed a significant positive correlation,and the absolute value of the slopes of the trait-trait relationships showed a gradually increasing trend with an increasing ontogenetic stage.LMA and LDMC showed a significant positive correlation,and the slopes of the trait-trait relationships showed a gradually decreasing trend with leaf age.Additionally,there were no significant relationships between leaf N content and LMA in most groups,which is contrary to the expectation of the LES.Overall,in the early ontogenetic stages and leaf ages,the leaf traits tend to be related to a"low investment-quick returns"resource strategy.In contrast,in the late ontogenetic stages and leaf ages,they tend to be related to a"high investment-slow returns"resource strategy.Our results reflect the optimal allocation of resources in Pinus koraiensis according to its functional needs during tree and leaf ontogeny.展开更多
Age and body size can influence predation risk and hence habitat use. Many species undergo ontogenetic shifts in habitat use as individuals grow larger and have different age-specific predation pressures. On coral ree...Age and body size can influence predation risk and hence habitat use. Many species undergo ontogenetic shifts in habitat use as individuals grow larger and have different age-specific predation pressures. On coral reefs, a number of fish species are more tolerant of threats in structurally complex habitats that contain more refuges than in less structurally complex habitats. However, we do not know how risk perception varies with age, and whether age interacts with habitat complexity. Adults and juveniles, because of their size, may face different risks in structurally simple versus complex habitats. We used flight initiation distanee as a metric to analyze perceptions of risk in a species of damselfish Stegastes nigricans. All else being equal, fish fleeing at greater distances are inferred to perceive higher risk. We targeted juvenile and adult damselfish to assess whether there are ontogenetic shifts in perceptions of safety in relation to structural complexity, inferred based on percent coral cover and rugosity. We found that adult damselfish tolerated closer approach in more complex habitats as measured by percent coral cover, but not rugosity, whereas juvenile fish always allowed closer approach than adult fish regardless of complexity. This ontogenetic shift in habitat use may result from juvenile fish taking bigger risks to maximize growth, whereas older animals, who are closer to their maximum body size, can afford to take fewer risks and protect their assets.展开更多
Body shape and metabolic rate can be important determinants of animal performance,yet often their effects on influential traits are evaluated in a non-integrated way.This creates an important gap because the integrati...Body shape and metabolic rate can be important determinants of animal performance,yet often their effects on influential traits are evaluated in a non-integrated way.This creates an important gap because the integration between shape and metabolism may be crucial to evaluate metabolic scaling theories.Here,we measured standard metabolic rate in 1-and 2-years old juvenile brown trout Salmo trutta,and used a geometric morphometrics approach to extricate the effects of ontogeny and size on the link between shape and metabolic scaling.We evidenced near-isometric ontogenetic scaling of metabolic rate with size,but also a biphasic pattern driven by a significant change in metabolic scaling,from positive to negative allometry.Moreover,the change in metabolic allometry parallels an ontogenetic change from elongate to deep-bodied shapes.This is consistent with the dynamic energy budget(DEB)and surface area(SA)theories,but not with the resource transport network theory which predicts increasing allometric exponents for trends towards more robust,three-dimensional bodies.In addition,we found a relationship between body shape and size independent metabolic rate,with a positive correlation between robustness and metabolic rate,which fits well within the view of Pace-of-Life Syndromes(POLS).Finally,our results align with previous studies that question the universality of metabolic scaling exponents and propose other mechanistic models explaining the diversity of metabolic scaling relationships or emphasizing the potential contribution of ecological factors.展开更多
Lagochilus proskorjakovii Ikram is a strict endemic in Nuratau ridge (north-western spurs of the mountain range of the Pamir-Alai). It grows as a part of Amygdalus bucharica and Perovskia scrophulariifolia formation, ...Lagochilus proskorjakovii Ikram is a strict endemic in Nuratau ridge (north-western spurs of the mountain range of the Pamir-Alai). It grows as a part of Amygdalus bucharica and Perovskia scrophulariifolia formation, where the total projective cover of grass does not exceed 20%. In natural conditions growth, ontogeny of L. proskorjakovii is simple and complete. The duration of ontogenesis in the condition of Nuratau is no more than 22 - 23 years. Studied coenopopulations are normal, but are not complete. Coenopopulation self-maintenance is carried out by the seed of renewal. The characteristic spectrum of coenopopulation centered, with a peak in the middle-generative individuals. In most cases, specific developmental spectrum of coenopopulation coincides with the characteristic ones. The absence or small proportion of the young fraction in surveyed of coenopopulation is related to the elimination of young fragile individuals. According to the classification of “delta-omega”, the most of coenopopulations are maturing which confirms the positive state of coenopopulation demography. Studied the ontogeny and structure of adult endemic Nuratau established that the species belongs to caudexum shrubs, perennial that forms the axis of the short multicipital caudex. Buds renewal is at a height of 2 - 3 cm above the substrate. Investigated coenopopulations L. proskorjakovii are successiveness conditions. In addition to the Artemisia juncea + Perovskia scrophulariifolia + Ferula ovina + Stipa hohenackeriana community 1<sup>st</sup> coenopopulation (CP) mature;the 2<sup>nd</sup> CP is mature which was a part of the Amygdalus bucharica + Perovskia scrophulariifolia + Prangos pobularia + Bromus scoparius community;3<sup>rd</sup> CP is maturing being a part of Lonicera nummulariifolia + Perovskia scrophulariifolia + Hypericum scabrum + Bromus danthoniae community and the 4<sup>th</sup> CP is mature which occurred in Amygdalus bucharica + Ferula varia + Acroptilon repens + Taeniatherum crinitum plant community.展开更多
When constraints on antipredator coloration shift over the course of development,it can be advantageous for animals to adopt different color strategies for each life stage.Many caterpillars in the genus Papilio exhibi...When constraints on antipredator coloration shift over the course of development,it can be advantageous for animals to adopt different color strategies for each life stage.Many caterpillars in the genus Papilio exhibit unique ontogenetic color sequences:for example,early instars that masquerade as bird feces,with later instars possessing eyespots.I hypothesize that larvae abandon feces masquerade in favor of eyespots due to ontogenetic changes in signaler size.This ontogenetic pattern also occurs within broader seasonal shifts in background color and predator activity.I conducted predation experiments with artificial prey to determine how potential signaling constraints(specifically size and season)shape predation risk,and consequently the expression of ontogenetic color change in Papilio larvae.Seasonally,both predation and background greenness declined significantly from July to September,though there was little evidence that these patterns impacted the effectiveness of either color strategy.Caterpillar size and color strongly affected the attack rate of avian predators:attacks increased with prey size regardless of color,and eyespotted prey were attacked more than masquerading prey overall.These results may reflect a key size-mediated tradeoff between conspicuousness and intimidation in eyespotted prey,and raise questions about how interwoven aspects of behavior and signal environment might maintain the prevalence of large,eyespotted larvae in nature.展开更多
Predicting species abundance is one of the most fundamental pursuits of ecology.Combining the information encoded in functional traits and metacommunities provides a new perspective to predict the abundance of species...Predicting species abundance is one of the most fundamental pursuits of ecology.Combining the information encoded in functional traits and metacommunities provides a new perspective to predict the abundance of species in communities.We applied a community assembly via trait selection model to predict quadrat-scale species abundances using functional trait variation on ontogenetic stages and metacommunity information for over 490 plant species in a subtropical forest and a lowland tropical forest in Yunnan,China.The relative importance of trait-based selection,mass effects,and stochasticity in shaping local species abundances is evaluated using different null models.We found both mass effects and trait selection contribute to local abundance patterns.Trait selection was detectable at all studied spatial scales(0.04e1 ha),with its strength stronger at larger scales and in the subtropical forest.In contrast,the importance of stochasticity decreased with spatial scale.A significant mass effect of the metacommunity was observed at small spatial scales.Our results indicate that tree community assembly is primarily driven by ontogenetic traits and metacommunity effects.Our findings also demonstrate that including ontogenetic trait variation into predictive frameworks allows ecologists to infer ecological mechanisms operating in community assembly at the individual level.展开更多
Ontogenetic structure of eight coenopopulations of Tulipa korolkowii Regel were studied in Uzbekistan.Resistance mechanisms of Tulipa korolkowii coenopopulations are shown:seed and vegetative methods of self-maintenan...Ontogenetic structure of eight coenopopulations of Tulipa korolkowii Regel were studied in Uzbekistan.Resistance mechanisms of Tulipa korolkowii coenopopulations are shown:seed and vegetative methods of self-maintenance of coenopopulations.Coenopopulations(CP)of T.korolkovii studied in normal.CP 1,2,6,7,8 complete,and the rest(3,4,5)are incomplete,no senile individuals.Absence of old specimens in coenopopulation connected with die-off great number plants in generative period of ontogenesis.展开更多
Hippopotamidae is currently represented by the common hippo(Hippopotamus amphibius)and the pygmy one(Choeropsis liberiensis).Hippopotamus amphibius is a gregarious,social,and polygamous animal characterized by a semi-...Hippopotamidae is currently represented by the common hippo(Hippopotamus amphibius)and the pygmy one(Choeropsis liberiensis).Hippopotamus amphibius is a gregarious,social,and polygamous animal characterized by a semi-aquatic lifestyle,widely populating African fluvial and lacustrine systems.The common hippopotamus displays features such as high orbits on the cranial roof,high nostrils on the snout,webbed toes,and a complex skin adapted for an amphibious lifestyle(Lewison&Pluháˇcek 2017).Hippopotamus is characterized by a limited body size dimorphism(Shannon et al.2021)and is primarily a grazer,feeding largely on C4 plants(e.g.grass),but also including C3 plants in its diet(Cerling et al.2008).On the other hand,C.liberiensis is a solitary mammal,exhibiting nocturnal habits and adaptations for a more terrestrial environment,such as less webbed toes and low orbits(Eltringham 1999).Weston(2003)reported sexually dimorphic canines in C.liberiensis,with males exhibiting bigger tusks than females.展开更多
Horseshoe crabs,the most well-known example of“living fossils”,are iconic and ecologically important macroinvertebrates in coastal and estuarine ecosystems.Their blood is a crucial resource for manufacturing Limulus...Horseshoe crabs,the most well-known example of“living fossils”,are iconic and ecologically important macroinvertebrates in coastal and estuarine ecosystems.Their blood is a crucial resource for manufacturing Limulus or Tachypleus amebocyte lysate to detect bacterial endotoxins or fungal contamination in drug and medical devices.An enhanced understanding of their ecological roles and trophic interactions in the food webs is fundamental to facilitate resource management for the declining populations in Asia.Foraging information of the Asian species,however,is mainly derived from preliminary,scattered reports from a limited number of study locations.In this study,resource utilization,trophic niche dynamics,and trophic interaction of the juvenile tri-spine horseshoe crab,Tachypleus tridentatus(instars 1–12,approximately 0.5–8 years old)across ontogeny was assessed in diversified nursery habitats along the northern Beibu Gulf,China,using carbon and nitrogen stable isotopes.Our results suggest that:(i)T.tridentatus are ecological generalists given the vast range of carbon isotopic values and trophic niche width estimates exhibited between multiple instar groups;(ii)juvenile T.tridentatus across most habitat types predominantly assimilated energy from a variety of basal production sources in the food web,but primarily depended on sedimentary organic matter and seagrass resource pools;(iii)ontogenetic shifts in juvenile dietary proportions were evident,with decreased reliance on sedimentary organic matter,coupled with increased reliance on benthic macroinvertebrate grazers,detritivores,and omnivores with age;and(iv)nearly all juvenile instars occupied similar trophic positions in the food web with slight shifts in trophic position present with increasing size.Our findings indicate that resource availability and ontogenetic diet shifts strongly influence horseshoe crab trophic dynamics,and age should be accounted when formulating habitat conservation measures based on resource use for Asian horseshoe crabs.展开更多
Aims We compared vein and stomatal traits of seedlings and adults of three Mediterranean Quercus species.Previous work suggests that gas-exchange rates tend to be higher at the seedling stage than in adults.Our object...Aims We compared vein and stomatal traits of seedlings and adults of three Mediterranean Quercus species.Previous work suggests that gas-exchange rates tend to be higher at the seedling stage than in adults.Our objective was to determine whether vein and stomatal traits vary throughout whole-plant ontogeny in parallel with the changes in gas-exchange rates.We addressed the following alternative hypotheses:hypothesis 1—seedlings show higher vein and stomatal densities than adults;and hypothesis 2—seedlings have lower investments in vascular tissues to reduce construction costs.Methods Ten specimens from each growth stage were randomly sampled for each species in a location in central-western Spain.We measured mean stomatal and vein traits(size and number of stomata per unit of leaf area,vein density,vein volume,vein to epidermis distance),leaf mass per area and lamina thickness.Important Findings Minor vein density and vein volume per area increased with tree age,which seems inconsistent with the ontogenetic trends in gas-exchange rates.This discrepancy is in support of our hypothesis 2,and it suggests that,at the seedling stage,reducing investments in vascular tissues in benefit of maximizing growth rates is a priority.Larger interveinal distances in seedlings were compensated by smaller vein to epidermis distances.The thin leaves of the seedlings may thus constitute as a necessary trait for achieving shorter path length distances for the transport of water to evaporation sites without the need for a strong investment in costly vascular tissues.展开更多
Siberian taimen Hucho taimen(Pallas,1773)is a broadly distributed and popular sport fish with high economic value.However,low abundance and hard-to-reach habitat make the Siberian taimen a relatively understudied spec...Siberian taimen Hucho taimen(Pallas,1773)is a broadly distributed and popular sport fish with high economic value.However,low abundance and hard-to-reach habitat make the Siberian taimen a relatively understudied species.Here we describe the morphological variability of two size groups of Siberian taimen juveniles from the eastern(Amur River basin)and western(Kama River basin)parts of the species distribution.The largest morphological differentiation of Siberian taimen juveniles was observed at the inter-basin level.In the Amur River basin,Siberian taimen juveniles also differed morphologically even at sites located at a distance of 20 km from each other,which may be explained by a small home-range inhabitation of juveniles leading to the formation of their morphotype determined by local environmental conditions.The pattern of allometry varies in taimen from different rivers,which could be related to the ontogenetic shift of ecological niches and the level of heterogeneity of the river environment.展开更多
The contradiction between the supply and demand of edible vegetable oil in China is prominent,and the self-sufficiency rate is less than 35%.Peanut has a very outstanding status in ensuring the security of edible oil ...The contradiction between the supply and demand of edible vegetable oil in China is prominent,and the self-sufficiency rate is less than 35%.Peanut has a very outstanding status in ensuring the security of edible oil and food.The emphasis of increasing peanut yield should be the improvement of pod yield per unit area,because the total yield of peanut has not increased as required.This is attributed to mainly two factors-low increase in the crop productivity and the competition for land for grain and cotton crops.For traditional double-seed sowing pattern,it is difficult to further increase the peanut yield due to the serious contradiction between populations and individuals and the declining population quality under high-yield conditions.Single-seed precision sowing was proven to be a new way to increase the economic coefficient(economic yield/biological yield)with the basic stability of the total biomass,which could make plants distribute evenly,reduce the competition among individuals and attain the full production potential of single plant.In order to reveal the mechanism of increasing peanut yield by single-seed precision sowing,the effects on the ontogenetic development(plant character,physiological characteristic and nutrient utilization)and population structure(population uniformity and photosynthesis,source-sink relationship and yield composition)were systematically expounded.This study reports establishment of the high-yield cultivation technology system with the key technology of single-seed precision sowing and the supporting technology of fertilizing and management.We anticipate its wider application for the improvement of peanut yield.展开更多
Lepidium subcordatum Botsch. et Vved. (Brassicaceae) is a rare endemic species of relict mountains of the Kyzylkum desert. The plant is listed in the “Red Data Book of Uzbekistan”. It grows on stony and rocky slopes...Lepidium subcordatum Botsch. et Vved. (Brassicaceae) is a rare endemic species of relict mountains of the Kyzylkum desert. The plant is listed in the “Red Data Book of Uzbekistan”. It grows on stony and rocky slopes of relict mountains. The ontogenetic structure of five coenotypical populations of this taxa growing in the Kuldzhuktau and Auminzatau mountains had been revealed. The ontogenesis duration is more than 20 years in natural habitats. All investigated coenopopulations can be assessed as normal and incomplete. The typical spectrum of coenopopulations is centralized with a peak in the middle-generative individuals. The ontogenetic spectrum of the most studied coenopopulations coincides with the characteristic ontogenetic structure that indicates a favorable environmental condition in region for self-maintenance of L. subcordatum coenopopulations.展开更多
We evaluated the feeding ecology of largehead hairtail (Trichiurus lepturus) and hairtail (T. margarites). We collected specimens from fishing ports in the Beibu Gulf (Gulf of Tonkin) from October 2008 to September 20...We evaluated the feeding ecology of largehead hairtail (Trichiurus lepturus) and hairtail (T. margarites). We collected specimens from fishing ports in the Beibu Gulf (Gulf of Tonkin) from October 2008 to September 2009 and analyzed their gut contents. We collected 857 T. lepturus and 666 T. margarites samples. The number of stomachs examined in this study was sufficient to describe the monthly and ontogenetic diet shifts for the two species, as indicated by the trophic diversity curves. T. lepturus was a general omnivore, feeding primarily on Bregmaceros rarisquamosu, Decapterus maruadsi, and Acetes chinensis. Conversely, T. margarites preyed primarily on D. maruadsi, B. rarisquamosus, B. nectabanus, and A. chinensis. Both species exhibited distinct ontogenetic diet shifts. Although the two hairtail specie fed on similar sources in the same habitat, the diet overlap was relatively low. Our results suggest that hairtail play an important role in controlling small pelagic and benthic fish populations in the gulf. This trophic correlation shall be used for developing a marine ecosystem model for the Beibu Gulf.展开更多
The current state of coenotic populations of rare and endangered species of Uzbekistan-Tulipa micheliana Hoog is given. Based on the analysis of demographic indicators and a number of organisms and population signs, t...The current state of coenotic populations of rare and endangered species of Uzbekistan-Tulipa micheliana Hoog is given. Based on the analysis of demographic indicators and a number of organisms and population signs, the state of the cenotic populations of the species was assessed, during the 2012-2018 years studied 15 cenopopulations different ecological-phytocenotic conditions in Uzbekistan.展开更多
Background： Information about competition responses is mainly available for monospecific stands or mixed stands with a small number of species. Studies on complex multi-species and highly structured forest ecosystems...Background： Information about competition responses is mainly available for monospecific stands or mixed stands with a small number of species. Studies on complex multi-species and highly structured forest ecosystems are scarce. Accordingly, the objective of this study was to quantify competition effects and analyse competition responses in a species-diverse afrotemperate forest in South Africa, based on an observational study with mapped tree positions and long-term diameter increment records. Methods： The sensitivity to competition was analysed for individual species and involved the calculation of the slope of the linear relation between the value of a competition index （CI） and diameter growth as a measure of sensitivity. In a next step different competition indices were combined and tree diameters were grouped in three classes as surrogates for canopy status and ontogenetic stage. Results： Five competition indices were found to be effective in showing sensitivity to competition for a number of canopy and sub-canopy species. Significant linear regressions were fitted for 18 of a total of 25 species. Species reactions varied significantly in their sensitivity to the different CIs. The indices were classified as belonging to two groups, those that responded more to local crowding and those that are more sensitive to overtopping, which revealed species-specific sensitivities to both factors. The analysis based on diameter classes revealed that species clearly changed their sensitivity to crowding or overtopping depending on diameter. Canopy and sub-canopy species showed distinct differences in their reactions. Conclusions： The application of multiple CIs brought novel insights relating to the dynamics of afrotemperate forests. The response patterns to different competition indices that focus on crowding and overtopping are varied and tree diameter dependent, indicating that oversimplified assumptions are not warranted in the interpretation of Cl- growth relations.展开更多
The metazoan Quadrapyrgites consists, from proximal to distal ends, of an oral area, a cone, a collar, and an apex from the Early Cambrian Fortunian Stage in Xixiang Zhangjiagou section, southern Shaanxi Province, Sou...The metazoan Quadrapyrgites consists, from proximal to distal ends, of an oral area, a cone, a collar, and an apex from the Early Cambrian Fortunian Stage in Xixiang Zhangjiagou section, southern Shaanxi Province, South China. Three morphological types of the apex, the most characteristic feature of the taxon, are identified from hundreds of Quadrapyrgites specimens. The Quadrapyrgites growth zone is situated at the oral end, where 12 terminal lobes are generated, uplifted, enlarged, and evaginated to form a crest; A one-by-one of crest number from 2 to 13 has been recognized. The unique growth pattern and ontogenetic sequence refute a cubozoan or cycloneuralian affinity for Olivooides and Quadrapyrgites, and instead defend a coronate scyphozoan hypothesis. An embryonic development and ontogenetic sequence with embryo and crest is constructed.展开更多
基金funded by the Natural Science Foundation Project of Sichuan Science and Technology Department (2018JY0305)Key Projects of the Natural Science Foundation of Sichuan Education Department (18ZA0002)
文摘Environmental variations and ontogeny may affect plant morphological traits and biomass allocation patterns that are related to the adjustments of plant ecological strategies. We selected 2-, 3-and 4-year-old Fritillaria unibracteata plants to explore the ontogenetic and altitudinal changes that impact their morphological traits(i.e., plant height, single leaf area,and specific leaf area) and biomass allocations [i.e.,biomass allocations of roots, bulbs, leaves, stems, and flowers] at relatively low altitudinal ranges(3400 m to 3600 m asl) and high altitudinal ranges(3600 m to4000 m asl). Our results indicated that plant height,root biomass allocation, and stem biomass allocation significantly increased during the process of individual growth and development, but single leaf area, specific leaf area, bulb biomass allocation, and leaf biomass allocation showed opposite trends.Furthermore, the impacts of altitudinal changes on morphological traits and biomass allocations had no significant differences at low altitude, except for single leaf area of 2-year-old plants. At high altitude,significantly reduced plant height, single leaf area and leaf biomass allocation for the 2-year-old plants,specific leaf area for the 2-and 4-year-old plants, and stem biomass allocation were found along altitudinal gradients. Significantly increased sexual reproductive allocation and relatively stable single leaf area and leaf biomass allocation were also observed for the 3-and 4-year-old plants. In addition, stable specific leaf area for the 3-year-old plants and root biomass allocation were recorded. These results suggested that the adaptive adjustments of alpine plants, in particular F. unibracteata were simultaneously influenced by altitudinal gradients and ontogeny.
基金The National Natural Science Foundation of China under contract No.NSFC4147129the China Postdoctoral Science Foundation under contract No.2017M610277+1 种基金the Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources(Shanghai Ocean University),Ministry of Education under contract No.A1-0203-00-2009-6the Fund of Key Laboratory of Open-Sea Fishery Development,Ministry of Agriculture,China under contract LOF 2018-02
文摘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.
基金Supported by the National Natural Science Foundation of China(No.41076110)the National Basic Research Program of China(973 Program)(No.2011CB409805)
文摘Based on two bottom trawl surveys conducted in autumn 2000 and 2001,a total of 1106 stomach samples of Bombay duck Harpadon nehereus between 23–278 mm fork length were collected and analyzed.The results show that Bombay duck prey items consisted of 11 groups or 32 species,of which Apogon lineatus,Leptochela gracilis,Acetes chinensis,and Euphausia pacifi ca were the dominant prey species.Ontogenetic variations were found in feeding habits and feeding activity of Bombay duck.Feeding activity was highest in fi sh smaller than 50 mm,lowest in fi sh between 50 and 99 mm,and then increased with increasing size thereafter.As Bombay duck size increased,fi sh prey increased in importance,whereas euphausiids and decapods decreased in importance.Different trophic guilds were observed in feeding habits across the examined size range.Bombay duck smaller than 50 mm were zooplanktivores,mainly feeding on zooplankton and fi sh larva;those between 50 and 149 mm were generalist predators,mainly feeding on pelagic shrimps,demersal shrimps and fi shes;and those larger than 150 mm were piscivores,mainly feeding on fi shes.
基金The work was financially supported by the National Natural Science Foundation of China(No.31971636)Yong Elite Scientists Sponsorship Program by CAST(2018QNRC001)the Fundamental Research Fund for the Central Universities(2572018CG03).
文摘Investigating the effects of ontogenetic stage and leaf age on leaf traits is important for understanding the utilization and distribution of resources in the process of plant growth.However,few studies have been conducted to show how traits and trait-trait relationships change across a range of ontogenetic stage and leaf age for evergreen coniferous species.We divided 67 Pinus koraiensis Sieb.et Zucc.of various sizes(0.3-100 cm diameter at breast height,DBH)into four ontogenetic stages,i.e.,young trees,middle-aged trees,mature trees and over-mature trees,and measured the leaf mass per area(LMA),leaf dry matter content(LDMC),and mass-based leaf nitrogen content(N)and phosphorus content(P)of each leaf age group for each sampled tree.One-way analysis of variance(ANOVA)was used to describe the variation in leaf traits by ontogenetic stage and leaf age.The standardized major axis method was used to explore the effects of ontogenetic stage and leaf age on trait-trait relationships.We found that LMA and LDMC increased significantly and N and P decreased significantly with increases in the ontogenetic stage and leaf age.Most trait-trait relationships were consistent with the leaf economic spectrum(LES)at a global scale.Among them,leaf N content and LDMC showed a significant negative correlation,leaf N and P contents showed a significant positive correlation,and the absolute value of the slopes of the trait-trait relationships showed a gradually increasing trend with an increasing ontogenetic stage.LMA and LDMC showed a significant positive correlation,and the slopes of the trait-trait relationships showed a gradually decreasing trend with leaf age.Additionally,there were no significant relationships between leaf N content and LMA in most groups,which is contrary to the expectation of the LES.Overall,in the early ontogenetic stages and leaf ages,the leaf traits tend to be related to a"low investment-quick returns"resource strategy.In contrast,in the late ontogenetic stages and leaf ages,they tend to be related to a"high investment-slow returns"resource strategy.Our results reflect the optimal allocation of resources in Pinus koraiensis according to its functional needs during tree and leaf ontogeny.
文摘Age and body size can influence predation risk and hence habitat use. Many species undergo ontogenetic shifts in habitat use as individuals grow larger and have different age-specific predation pressures. On coral reefs, a number of fish species are more tolerant of threats in structurally complex habitats that contain more refuges than in less structurally complex habitats. However, we do not know how risk perception varies with age, and whether age interacts with habitat complexity. Adults and juveniles, because of their size, may face different risks in structurally simple versus complex habitats. We used flight initiation distanee as a metric to analyze perceptions of risk in a species of damselfish Stegastes nigricans. All else being equal, fish fleeing at greater distances are inferred to perceive higher risk. We targeted juvenile and adult damselfish to assess whether there are ontogenetic shifts in perceptions of safety in relation to structural complexity, inferred based on percent coral cover and rugosity. We found that adult damselfish tolerated closer approach in more complex habitats as measured by percent coral cover, but not rugosity, whereas juvenile fish always allowed closer approach than adult fish regardless of complexity. This ontogenetic shift in habitat use may result from juvenile fish taking bigger risks to maximize growth, whereas older animals, who are closer to their maximum body size, can afford to take fewer risks and protect their assets.
基金This work was supported by the Principality of Asturias(grant no.CN-07-164)the Spanish Government(grants no.MEC-CGL2004-03239/BOS and MMA/86-2003-1)FICYT(predoctoral fellowship BPO4-147 to J.R.S.G.)。
文摘Body shape and metabolic rate can be important determinants of animal performance,yet often their effects on influential traits are evaluated in a non-integrated way.This creates an important gap because the integration between shape and metabolism may be crucial to evaluate metabolic scaling theories.Here,we measured standard metabolic rate in 1-and 2-years old juvenile brown trout Salmo trutta,and used a geometric morphometrics approach to extricate the effects of ontogeny and size on the link between shape and metabolic scaling.We evidenced near-isometric ontogenetic scaling of metabolic rate with size,but also a biphasic pattern driven by a significant change in metabolic scaling,from positive to negative allometry.Moreover,the change in metabolic allometry parallels an ontogenetic change from elongate to deep-bodied shapes.This is consistent with the dynamic energy budget(DEB)and surface area(SA)theories,but not with the resource transport network theory which predicts increasing allometric exponents for trends towards more robust,three-dimensional bodies.In addition,we found a relationship between body shape and size independent metabolic rate,with a positive correlation between robustness and metabolic rate,which fits well within the view of Pace-of-Life Syndromes(POLS).Finally,our results align with previous studies that question the universality of metabolic scaling exponents and propose other mechanistic models explaining the diversity of metabolic scaling relationships or emphasizing the potential contribution of ecological factors.
文摘Lagochilus proskorjakovii Ikram is a strict endemic in Nuratau ridge (north-western spurs of the mountain range of the Pamir-Alai). It grows as a part of Amygdalus bucharica and Perovskia scrophulariifolia formation, where the total projective cover of grass does not exceed 20%. In natural conditions growth, ontogeny of L. proskorjakovii is simple and complete. The duration of ontogenesis in the condition of Nuratau is no more than 22 - 23 years. Studied coenopopulations are normal, but are not complete. Coenopopulation self-maintenance is carried out by the seed of renewal. The characteristic spectrum of coenopopulation centered, with a peak in the middle-generative individuals. In most cases, specific developmental spectrum of coenopopulation coincides with the characteristic ones. The absence or small proportion of the young fraction in surveyed of coenopopulation is related to the elimination of young fragile individuals. According to the classification of “delta-omega”, the most of coenopopulations are maturing which confirms the positive state of coenopopulation demography. Studied the ontogeny and structure of adult endemic Nuratau established that the species belongs to caudexum shrubs, perennial that forms the axis of the short multicipital caudex. Buds renewal is at a height of 2 - 3 cm above the substrate. Investigated coenopopulations L. proskorjakovii are successiveness conditions. In addition to the Artemisia juncea + Perovskia scrophulariifolia + Ferula ovina + Stipa hohenackeriana community 1<sup>st</sup> coenopopulation (CP) mature;the 2<sup>nd</sup> CP is mature which was a part of the Amygdalus bucharica + Perovskia scrophulariifolia + Prangos pobularia + Bromus scoparius community;3<sup>rd</sup> CP is maturing being a part of Lonicera nummulariifolia + Perovskia scrophulariifolia + Hypericum scabrum + Bromus danthoniae community and the 4<sup>th</sup> CP is mature which occurred in Amygdalus bucharica + Ferula varia + Acroptilon repens + Taeniatherum crinitum plant community.
文摘When constraints on antipredator coloration shift over the course of development,it can be advantageous for animals to adopt different color strategies for each life stage.Many caterpillars in the genus Papilio exhibit unique ontogenetic color sequences:for example,early instars that masquerade as bird feces,with later instars possessing eyespots.I hypothesize that larvae abandon feces masquerade in favor of eyespots due to ontogenetic changes in signaler size.This ontogenetic pattern also occurs within broader seasonal shifts in background color and predator activity.I conducted predation experiments with artificial prey to determine how potential signaling constraints(specifically size and season)shape predation risk,and consequently the expression of ontogenetic color change in Papilio larvae.Seasonally,both predation and background greenness declined significantly from July to September,though there was little evidence that these patterns impacted the effectiveness of either color strategy.Caterpillar size and color strongly affected the attack rate of avian predators:attacks increased with prey size regardless of color,and eyespotted prey were attacked more than masquerading prey overall.These results may reflect a key size-mediated tradeoff between conspicuousness and intimidation in eyespotted prey,and raise questions about how interwoven aspects of behavior and signal environment might maintain the prevalence of large,eyespotted larvae in nature.
基金supported by the National Natural Science Foundation of China (31800353)the Yunnan Fundamental Research Projects (202101AV070005)+4 种基金Yunnan High Level Talents Special Support Plan (YNWR-QNBJ-2018-309)Strategic Priority Research Program of the Chinese Academy of Sciences (XDB31000000)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (Y202080)the West Light Foundation of the Chinese Academy of Sciencessupported by the National Science Foundation United States (NSF DEB-2029997)
文摘Predicting species abundance is one of the most fundamental pursuits of ecology.Combining the information encoded in functional traits and metacommunities provides a new perspective to predict the abundance of species in communities.We applied a community assembly via trait selection model to predict quadrat-scale species abundances using functional trait variation on ontogenetic stages and metacommunity information for over 490 plant species in a subtropical forest and a lowland tropical forest in Yunnan,China.The relative importance of trait-based selection,mass effects,and stochasticity in shaping local species abundances is evaluated using different null models.We found both mass effects and trait selection contribute to local abundance patterns.Trait selection was detectable at all studied spatial scales(0.04e1 ha),with its strength stronger at larger scales and in the subtropical forest.In contrast,the importance of stochasticity decreased with spatial scale.A significant mass effect of the metacommunity was observed at small spatial scales.Our results indicate that tree community assembly is primarily driven by ontogenetic traits and metacommunity effects.Our findings also demonstrate that including ontogenetic trait variation into predictive frameworks allows ecologists to infer ecological mechanisms operating in community assembly at the individual level.
基金The current research is done under the project PZ-20170919165 Inventory of rare and endangered species of vascular plants of Navoi and Bukhara regions.
文摘Ontogenetic structure of eight coenopopulations of Tulipa korolkowii Regel were studied in Uzbekistan.Resistance mechanisms of Tulipa korolkowii coenopopulations are shown:seed and vegetative methods of self-maintenance of coenopopulations.Coenopopulations(CP)of T.korolkovii studied in normal.CP 1,2,6,7,8 complete,and the rest(3,4,5)are incomplete,no senile individuals.Absence of old specimens in coenopopulation connected with die-off great number plants in generative period of ontogenesis.
基金granted by the FCT-Fundação para a Ciência e a Tecnologia[2021.08458.BD],Erasmus+grant[29,191(532)105/2022/SMT],and SYNTHESYS+[DETAF-TA4-0632022]D.F.was supported by the Ayuda del Programa de Formación de Profesorado Universitario(FPU20/03,389)+2 种基金is a PhD student at the Programa de Doctorado en Biología at the Universidad Complutense de Madrid.This research was also supported by FCT,I.P.through the Research Unit UIDB/04,035/2020(https://doi.org/10.54499/UIDB/04035/2020)L.P.is granted by SYNTHESYS+[BE-TAF-136]This project is funded by the European Union-Next Generation EU,call PRIN PNRR project P2022RZ4PL.
文摘Hippopotamidae is currently represented by the common hippo(Hippopotamus amphibius)and the pygmy one(Choeropsis liberiensis).Hippopotamus amphibius is a gregarious,social,and polygamous animal characterized by a semi-aquatic lifestyle,widely populating African fluvial and lacustrine systems.The common hippopotamus displays features such as high orbits on the cranial roof,high nostrils on the snout,webbed toes,and a complex skin adapted for an amphibious lifestyle(Lewison&Pluháˇcek 2017).Hippopotamus is characterized by a limited body size dimorphism(Shannon et al.2021)and is primarily a grazer,feeding largely on C4 plants(e.g.grass),but also including C3 plants in its diet(Cerling et al.2008).On the other hand,C.liberiensis is a solitary mammal,exhibiting nocturnal habits and adaptations for a more terrestrial environment,such as less webbed toes and low orbits(Eltringham 1999).Weston(2003)reported sexually dimorphic canines in C.liberiensis,with males exhibiting bigger tusks than females.
基金This research was supported by the National Natural Science Foundation of China(41706183,41901226)the Guangxi Natural Science Foundation(2017GXNSFBA198181)the Guangxi BaGui Youth Scholars Program,the Guangxi Recruitment Program of 100 Global Experts,and the Guangxi Postdoctoral Innovation Program.
文摘Horseshoe crabs,the most well-known example of“living fossils”,are iconic and ecologically important macroinvertebrates in coastal and estuarine ecosystems.Their blood is a crucial resource for manufacturing Limulus or Tachypleus amebocyte lysate to detect bacterial endotoxins or fungal contamination in drug and medical devices.An enhanced understanding of their ecological roles and trophic interactions in the food webs is fundamental to facilitate resource management for the declining populations in Asia.Foraging information of the Asian species,however,is mainly derived from preliminary,scattered reports from a limited number of study locations.In this study,resource utilization,trophic niche dynamics,and trophic interaction of the juvenile tri-spine horseshoe crab,Tachypleus tridentatus(instars 1–12,approximately 0.5–8 years old)across ontogeny was assessed in diversified nursery habitats along the northern Beibu Gulf,China,using carbon and nitrogen stable isotopes.Our results suggest that:(i)T.tridentatus are ecological generalists given the vast range of carbon isotopic values and trophic niche width estimates exhibited between multiple instar groups;(ii)juvenile T.tridentatus across most habitat types predominantly assimilated energy from a variety of basal production sources in the food web,but primarily depended on sedimentary organic matter and seagrass resource pools;(iii)ontogenetic shifts in juvenile dietary proportions were evident,with decreased reliance on sedimentary organic matter,coupled with increased reliance on benthic macroinvertebrate grazers,detritivores,and omnivores with age;and(iv)nearly all juvenile instars occupied similar trophic positions in the food web with slight shifts in trophic position present with increasing size.Our findings indicate that resource availability and ontogenetic diet shifts strongly influence horseshoe crab trophic dynamics,and age should be accounted when formulating habitat conservation measures based on resource use for Asian horseshoe crabs.
基金This work was supported by the European Regional Development Fund–Ministerio de Ciencia e Innovacion(CGL2016-79861-P).
文摘Aims We compared vein and stomatal traits of seedlings and adults of three Mediterranean Quercus species.Previous work suggests that gas-exchange rates tend to be higher at the seedling stage than in adults.Our objective was to determine whether vein and stomatal traits vary throughout whole-plant ontogeny in parallel with the changes in gas-exchange rates.We addressed the following alternative hypotheses:hypothesis 1—seedlings show higher vein and stomatal densities than adults;and hypothesis 2—seedlings have lower investments in vascular tissues to reduce construction costs.Methods Ten specimens from each growth stage were randomly sampled for each species in a location in central-western Spain.We measured mean stomatal and vein traits(size and number of stomata per unit of leaf area,vein density,vein volume,vein to epidermis distance),leaf mass per area and lamina thickness.Important Findings Minor vein density and vein volume per area increased with tree age,which seems inconsistent with the ontogenetic trends in gas-exchange rates.This discrepancy is in support of our hypothesis 2,and it suggests that,at the seedling stage,reducing investments in vascular tissues in benefit of maximizing growth rates is a priority.Larger interveinal distances in seedlings were compensated by smaller vein to epidermis distances.The thin leaves of the seedlings may thus constitute as a necessary trait for achieving shorter path length distances for the transport of water to evaporation sites without the need for a strong investment in costly vascular tissues.
文摘Siberian taimen Hucho taimen(Pallas,1773)is a broadly distributed and popular sport fish with high economic value.However,low abundance and hard-to-reach habitat make the Siberian taimen a relatively understudied species.Here we describe the morphological variability of two size groups of Siberian taimen juveniles from the eastern(Amur River basin)and western(Kama River basin)parts of the species distribution.The largest morphological differentiation of Siberian taimen juveniles was observed at the inter-basin level.In the Amur River basin,Siberian taimen juveniles also differed morphologically even at sites located at a distance of 20 km from each other,which may be explained by a small home-range inhabitation of juveniles leading to the formation of their morphotype determined by local environmental conditions.The pattern of allometry varies in taimen from different rivers,which could be related to the ontogenetic shift of ecological niches and the level of heterogeneity of the river environment.
基金supported by the National Natural Science Foundation of China(31601252 and 31571605)the National Key R&D Program of China(2018YFD0201000)+1 种基金the Natural Science Foundation of Shandong Province,China(BS2015SW020)the earmarked fund for China Agriculture Research System(CARS-13)。
文摘The contradiction between the supply and demand of edible vegetable oil in China is prominent,and the self-sufficiency rate is less than 35%.Peanut has a very outstanding status in ensuring the security of edible oil and food.The emphasis of increasing peanut yield should be the improvement of pod yield per unit area,because the total yield of peanut has not increased as required.This is attributed to mainly two factors-low increase in the crop productivity and the competition for land for grain and cotton crops.For traditional double-seed sowing pattern,it is difficult to further increase the peanut yield due to the serious contradiction between populations and individuals and the declining population quality under high-yield conditions.Single-seed precision sowing was proven to be a new way to increase the economic coefficient(economic yield/biological yield)with the basic stability of the total biomass,which could make plants distribute evenly,reduce the competition among individuals and attain the full production potential of single plant.In order to reveal the mechanism of increasing peanut yield by single-seed precision sowing,the effects on the ontogenetic development(plant character,physiological characteristic and nutrient utilization)and population structure(population uniformity and photosynthesis,source-sink relationship and yield composition)were systematically expounded.This study reports establishment of the high-yield cultivation technology system with the key technology of single-seed precision sowing and the supporting technology of fertilizing and management.We anticipate its wider application for the improvement of peanut yield.
文摘Lepidium subcordatum Botsch. et Vved. (Brassicaceae) is a rare endemic species of relict mountains of the Kyzylkum desert. The plant is listed in the “Red Data Book of Uzbekistan”. It grows on stony and rocky slopes of relict mountains. The ontogenetic structure of five coenotypical populations of this taxa growing in the Kuldzhuktau and Auminzatau mountains had been revealed. The ontogenesis duration is more than 20 years in natural habitats. All investigated coenopopulations can be assessed as normal and incomplete. The typical spectrum of coenopopulations is centralized with a peak in the middle-generative individuals. The ontogenetic spectrum of the most studied coenopopulations coincides with the characteristic ontogenetic structure that indicates a favorable environmental condition in region for self-maintenance of L. subcordatum coenopopulations.
基金Supported by the National Natural Science Foundation of China (No.30771653)the Bureau of Fisheries,Ministry of Agriculture,Department of Education of Guangdong Province (No.LYM09089)Guangdong Ocean University (No.2009-11)
文摘We evaluated the feeding ecology of largehead hairtail (Trichiurus lepturus) and hairtail (T. margarites). We collected specimens from fishing ports in the Beibu Gulf (Gulf of Tonkin) from October 2008 to September 2009 and analyzed their gut contents. We collected 857 T. lepturus and 666 T. margarites samples. The number of stomachs examined in this study was sufficient to describe the monthly and ontogenetic diet shifts for the two species, as indicated by the trophic diversity curves. T. lepturus was a general omnivore, feeding primarily on Bregmaceros rarisquamosu, Decapterus maruadsi, and Acetes chinensis. Conversely, T. margarites preyed primarily on D. maruadsi, B. rarisquamosus, B. nectabanus, and A. chinensis. Both species exhibited distinct ontogenetic diet shifts. Although the two hairtail specie fed on similar sources in the same habitat, the diet overlap was relatively low. Our results suggest that hairtail play an important role in controlling small pelagic and benthic fish populations in the gulf. This trophic correlation shall be used for developing a marine ecosystem model for the Beibu Gulf.
文摘The current state of coenotic populations of rare and endangered species of Uzbekistan-Tulipa micheliana Hoog is given. Based on the analysis of demographic indicators and a number of organisms and population signs, the state of the cenotic populations of the species was assessed, during the 2012-2018 years studied 15 cenopopulations different ecological-phytocenotic conditions in Uzbekistan.
基金support (data,scientific input) by South African National ParksFunding for this study was contributed by three projects,financed by the South African Department of Science and Technology through the National Research Foundation:i) the 'Green Landscapes' Project within the Global Change, Sustainability and Society Research Programme of the National Research Foundation(NRF) of South Africa,ⅱ)+1 种基金the EU Marie Curie Project "Climate Fit Forests" and ⅲ)the Project 'impact of drought on mortality,ingrowth and diameter increment in the afro-temperate forests of the Southern Cape, South Africa' funded by the NRF/DST Centre of Excellence of Tree Health and Biotechnology(CTHB) in Pretoria
文摘Background： Information about competition responses is mainly available for monospecific stands or mixed stands with a small number of species. Studies on complex multi-species and highly structured forest ecosystems are scarce. Accordingly, the objective of this study was to quantify competition effects and analyse competition responses in a species-diverse afrotemperate forest in South Africa, based on an observational study with mapped tree positions and long-term diameter increment records. Methods： The sensitivity to competition was analysed for individual species and involved the calculation of the slope of the linear relation between the value of a competition index （CI） and diameter growth as a measure of sensitivity. In a next step different competition indices were combined and tree diameters were grouped in three classes as surrogates for canopy status and ontogenetic stage. Results： Five competition indices were found to be effective in showing sensitivity to competition for a number of canopy and sub-canopy species. Significant linear regressions were fitted for 18 of a total of 25 species. Species reactions varied significantly in their sensitivity to the different CIs. The indices were classified as belonging to two groups, those that responded more to local crowding and those that are more sensitive to overtopping, which revealed species-specific sensitivities to both factors. The analysis based on diameter classes revealed that species clearly changed their sensitivity to crowding or overtopping depending on diameter. Canopy and sub-canopy species showed distinct differences in their reactions. Conclusions： The application of multiple CIs brought novel insights relating to the dynamics of afrotemperate forests. The response patterns to different competition indices that focus on crowding and overtopping are varied and tree diameter dependent, indicating that oversimplified assumptions are not warranted in the interpretation of Cl- growth relations.
基金supported by the National Natural Science Foundation of China (grant #s 41072012)the State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences (#s 113115 and 20132107)+1 种基金the Key Project of Central University Fund (CHD2012ZD017)the College Students’ Innovative Entrepreneurial Training Program of Chang’an University (Grant No.201510710060,201510710056 and 201510710179)
文摘The metazoan Quadrapyrgites consists, from proximal to distal ends, of an oral area, a cone, a collar, and an apex from the Early Cambrian Fortunian Stage in Xixiang Zhangjiagou section, southern Shaanxi Province, South China. Three morphological types of the apex, the most characteristic feature of the taxon, are identified from hundreds of Quadrapyrgites specimens. The Quadrapyrgites growth zone is situated at the oral end, where 12 terminal lobes are generated, uplifted, enlarged, and evaginated to form a crest; A one-by-one of crest number from 2 to 13 has been recognized. The unique growth pattern and ontogenetic sequence refute a cubozoan or cycloneuralian affinity for Olivooides and Quadrapyrgites, and instead defend a coronate scyphozoan hypothesis. An embryonic development and ontogenetic sequence with embryo and crest is constructed.
