Proline contents of parotid glands (PG) in pigs constantly increase after the inclusion of different amounts of ripe hulled acorns in the diet providing high polyphenols levels. The dose-response relationship was esti...Proline contents of parotid glands (PG) in pigs constantly increase after the inclusion of different amounts of ripe hulled acorns in the diet providing high polyphenols levels. The dose-response relationship was estimated on natural hydrolizable tannins (expressed as tannic acid equivalent TAE) amounts of 25.8 to 36.1 g TAE/kg DM in experimental diets. Macroscopic and histological morphometry of parotid glands greatly varied according to feed intake and dosages of TAE ingested. The PG response (hypertrophy grade) on acorns’ tannins content in the diet was positively correlated (R2 = 0.748): the response to the protein precipitating activity (PPA) of tannins consisted of a functional parotidomegaly (hypertrophy), 1.34 up to 3.55 folds than control PGs, following an oral dosage 0.596 up 1.72 TAE g·kg body weight·d-1 respectively, after one week exposure.展开更多
We collected acorns from selected Quercus robur and Quercus petraea mother trees growing at sta- tions with different depths to the water table. We produced pairs of micro-cuttings from these single acorns. The obtain...We collected acorns from selected Quercus robur and Quercus petraea mother trees growing at sta- tions with different depths to the water table. We produced pairs of micro-cuttings from these single acorns. The obtained pairs of cuttings represented phenotypes of high similarity according to photosynthetic parameters. These pairs of cuttings were used to test the plasticity of response to contrasting water regimes. For each pair, one cutting was submitted to drought and the other was submitted to waterlogging. Drought response was recorded according to gas exchange traits （stomatal closure and water use effi- ciency）. The response to waterlogging was recorded according to the capacity to form hypertrophied lenticels and to maintain the CO2 assimilation rate. Intermediary phenotypes presenting both high water use efficiency and the capacity to develop hypertrophied lenticels were expected.展开更多
Quercus is the largest genus within the Fagaceae and has a rich fossil record.Most of the fossil material is attributed to the subgenus Quercus based on leaves,pollen or rarely acorns and nuts.Fossil records of Q.sect...Quercus is the largest genus within the Fagaceae and has a rich fossil record.Most of the fossil material is attributed to the subgenus Quercus based on leaves,pollen or rarely acorns and nuts.Fossil records of Q.section Cyclobalanopsis characterized by ring-cupped acorns are relatively few and especially those described based on nuts are scant.In this study,we described four new species of Quercus section Cyclobalanopsis based on mummified acorns and nuts:Q.paleodisciformis X.Y.Liu et J.H.Jin sp.nov.,Q.paleohui X.Y.Liu et J.H.Jin sp.nov.,Q.nanningensis X.Y.Liu et J.H.Jin sp.nov.and Q.yongningensis X.Y.Liu et J.H.Jin sp.nov.These species closely resemble the extant species Q.disciformis,Q.hui,Q.kerrii,and Q.dinghuensis.The occurrence of Q.section Cyclobalanopsis in the Oligocene stratum of Guangxi,South China,suggests that the section has diversified within its extant distribution center since the Oligocene.By combining records from other areas,we propose that the section first appeared in the middle Eocene of East Asia(Sino-Japan),has diversified in situ with a few elements scattering into West Asia and southern Europe since the Oligocene and Pliocene,respectively,and finally became restricted in East Asia since the Pleistocene.This indicates that the section originated and diversified in East Asia,before spreading into West Asia no later than the Oligocene and into southern Europe by the Pliocene.Subsequently it disappeared from South Europe and West Asia due to the appearance of the(summer dry)Mediterranean climate and widespread cooling during the Pleistocene.展开更多
Oaks(Quercus spp.)provide an important food source for many wildlife species throughout the fall and winter.Most research evaluating oak masting patterns and the subsequent behavioral responses of wildlife focuses on ...Oaks(Quercus spp.)provide an important food source for many wildlife species throughout the fall and winter.Most research evaluating oak masting patterns and the subsequent behavioral responses of wildlife focuses on the annual temporal scale.However,patterns in masting at the seasonal temporal scale may be important for wildlife behavior.We designed a study quantifying seasonal oak masting patterns of 3 oak species(water oak,Q.nigra;laurel oak,Q.laurifolia;and swamp chestnut oak,Q.michauxii)and linking those patterns to visitation and feeding behavior of 3 primary consumers(white-tailed deer,Odocoileus virginianus;gray squirrel,Sciurus carolinensis;and raccoon,Procyon lotor).We used seed traps to monitor the seasonal masting pattern of 205 trees in the fall of 2021 and 2022 and used camera traps concurrently to monitor wildlife behavior associated with a subset of 30 trees.Seasonal masting patterns differed between oak species both within a season and across years,and the timing of mast varied within oak species across years.White-tailed deer tended to visit swamp chestnut oak as the number of acorns increased and consumed their acorns.Gray squirrels and raccoons tended to visit laurel oak and consume water oak acorns with gray squirrels being more likely to consume as the number of acorns increased.Our results indicate that evaluating acorn production at multiple temporal scales may be necessary to fully understand oak masting relationships with wildlife.Furthermore,differences in wildlife behavior based on oak species may have important implications for oak regeneration.展开更多
Acorn production in oaks(Quercus spp.)shows considerable inter-annual variation,known as masting.The effects of pollen sourced from trees within or outside the stand on acorn production were investigated in pedunculat...Acorn production in oaks(Quercus spp.)shows considerable inter-annual variation,known as masting.The effects of pollen sourced from trees within or outside the stand on acorn production were investigated in pedunculate oak(Quercus robur L.)in an ancient mixed woodland during two moderate masting years.Comparisons were made between natural pollination,hand pollinations with out-of-stand pollen,in-stand pollen or a 1:1 combination of the two pollen sources,and for bagged flowers left unpollinated.After all treatments,>85%of the flowers or developing acorns were aborted between May and August of both years.When flowers were protected with pollen bags and no pollen added,no acorns were produced.In contrast,hand pollination with out-of-stand pollen produced the most acorns both years and significantly more than within-stand pollen or natural pollination in 2022.Hand pollination with out-of-stand or within-stand pollen provided significantly more acorns than natural pollination in 2023.In 2022,hand pollination with a 1:1 mixture of out-of-stand and within-stand pollen yielded an intermediate number of mature acorns between those for the out-of-stand and within-stand pollination treatments.The study provides clear evidence of maternal choice during acorn development in pedunculate oak and of the benefits of pollen supplementation.It also confirms that pedunculate oak is a fruit-maturation masting species;abortion of pollinated flowers and immature acorns determines a mast year(rather than the number of flowers produced)at this site.展开更多
Fitness of parents and offspring is affected by offspring size.In oaks(Quercus spp.),acorns vary considerably in size across,and within,species.Seed size influences dispersal and establishment of oaks,but it is not kn...Fitness of parents and offspring is affected by offspring size.In oaks(Quercus spp.),acorns vary considerably in size across,and within,species.Seed size influences dispersal and establishment of oaks,but it is not known whether size imparts tolerance to seed predators.Here,we examine the relative extent to which cotyledon size serves as both a means for sustaining partial consumption and energy reserves for developing seedlings during early stages of establishment.Acorns of 6 oak species were damaged to simulate acorn predation by vertebrate and invertebrate seed predators.Seedling germination/emergence and growth rates were used to assess seedling performance.We predicted that if cotyledons are important for dispersal,acorns should show tolerance to partial seed consumption.Alternatively,if the cotyledon functions primarily as an energy reserve,damage should significantly influence seedling performance.Acorns of each species germinated and produced seedlings even after removing>50%of the cotyledon.Seed mass explained only some of the variation in performance.Within species,larger acorns performed better than smaller acorns when damaged.Undamaged acorns performed as well or better than damaged acorns.There was no pattern among individual species with increasing amounts of damage.In some species,simulated invertebrate damage resulted in the poorest performance,suggesting alternative strategies of oaks to sustain damage.Large cotyledons in acorns may be important for attracting seed dispersers and sustaining partial damage,while also providing energy to young seedlings.Success of oak establishment may follow from the resilience of acorns to sustain damage at an early stage.展开更多
The study investigated the effects of ethanol precipitation on the polysaccharide components obtained from 3 different oak acorns.The variables factors were ethanol precipitation times(1×or 2×),tree species(...The study investigated the effects of ethanol precipitation on the polysaccharide components obtained from 3 different oak acorns.The variables factors were ethanol precipitation times(1×or 2×),tree species(Quercus variabilis,Quercus aliena,Quercus dentata)and raw materials(whole acorn fruit or kernels).Through detections of acorn polysaccharide concentrations from different species and components analyses,we found that the second ethanol precipitation had a better extraction effect,and acorn polysaccharides were proved to be mainly composed of glucose,galacturonic acid,arabinose and galactose.Compared with other groups,the highest content of polysaccharides was proved to be extracted from Q.variabilis kernels,thus,acorn kernels should be suggested as the proper material for the extraction of acorn polysaccharides.Interestingly,acorn polysaccharides functionally alleviated liver and kidney damages in type 2 diabetes mice,they also had noticeable hypoglycemic effects and regulated insulin secretion,particularly in combination with metformin and D-mannuronic acid.展开更多
专注于中短期卷筒纸胶印业务的印刷企业Acorn Web Offset近期投资购置了一台全新的Komori G37 Lithrone单张纸胶印机,用以替换公司现有的封面印刷设备。Acorn Web Offset公司在位于西约克郡诺曼顿的工厂拥有约130名员工,这台全新引进的...专注于中短期卷筒纸胶印业务的印刷企业Acorn Web Offset近期投资购置了一台全新的Komori G37 Lithrone单张纸胶印机,用以替换公司现有的封面印刷设备。Acorn Web Offset公司在位于西约克郡诺曼顿的工厂拥有约130名员工,这台全新引进的印刷机计划于2025年最后一个季度正式投入使用,届时它将助力公司封面印刷的生产效率提升30%,并有效减少纸张浪费和能源消耗。展开更多
Studies from both tropical and temperate systems show that scatter-hoarding rodents selectively disperse larger seeds farther from their source than smaller seeds,potentially increasing seedling establishment in large...Studies from both tropical and temperate systems show that scatter-hoarding rodents selectively disperse larger seeds farther from their source than smaller seeds,potentially increasing seedling establishment in larger-seeded plants.Size-biased dispersal is evident in many oaks(Quercus)and is true both across and within species.Here,we predict that intraspecifc variation in seed size also influences acorn dispersal by the Blue Jay(Cyanocitta cristata Linnaeus),but in an opposite manner.Blue Jays are gape-limited and selectively disperse smaller acorn species(e.g.pin oaks[Quercus palustris Münchh]),but often carry several acorns in their crop during a single dispersal event.We predict that jays foraging on smaller acorns will load more seeds per trip and disperse seeds to greater distances than when single acorns are carried in the bill.To test this,we presented free-ranging Blue Jays with pin oak acorns of different sizes over a 2-year period.In each of 16 experimental trials,we monitored the birds at a feeding station with remote cameras and determined the number of acorns removed and the distance acorns were dispersed when cached.Jays were significantly more likely to engage in multiple seed loading with smaller seeds in both years of the study.During the second year,these smaller acorns were dispersed farther than larger acorns,and during the first year,larger acorns were dispersed farther,revealing an inconsistent response to seed size during our study.We suggest that in some circumstances,multiple seed loading by Blue Jays may favor dispersal in some plant species.展开更多
Acorn production in oak(Quercus spp.)shows considerable inter-annual variation,known as masting,which provides a natural defence against seed predators but a highly-variable supply of acorns for uses such as in commer...Acorn production in oak(Quercus spp.)shows considerable inter-annual variation,known as masting,which provides a natural defence against seed predators but a highly-variable supply of acorns for uses such as in commercial tree planting each year.Anthropogenic emissions of greenhouse gases have been very widely reported to influence plant growth and seed or fruit size and quantity via the‘fertilisation effect’that leads to enhanced photosynthesis.To examine if acorn production in mature woodland communities will be affected by further increase in CO_(2),the contents of litter traps from a Free Air Carbon Enrichment(FACE)experiment in deciduous woodland in central England were analysed for numbers of flowers and acorns of pedunculate oak(Quercus robur L.)at different stages of development and their predation levels under ambient and elevated CO_(2) concentrations.Inter-annual variation in acorn numbers was considerable and cyclical between 2015 and 2021,with the greatest numbers of mature acorns in 2015,2017 and 2020 but almost none in 2018.The numbers of flowers,enlarged cups,immature acorns,empty acorn cups,and galls in the litter traps also varied amongst years;comparatively high numbers of enlarged cups were recorded in 2018,suggesting Q.robur at this site is a fruit maturation masting species(i.e.,the extent of abortion of pollinated flowers during acorn development affects mature acorn numbers greatly).Raising the atmospheric CO_(2) concentration by 150μL L^(−1),from early 2017,increased the numbers of immature acorns,and all acorn evidence(empty cups+immature acorns+mature acorns)detected in the litter traps compared to ambient controls by 2021,but did not consistently affect the numbers of flowers,enlarged cups,empty cups,or mature acorns.The number of flowers in the elevated CO_(2) plots’litter traps was greater in 2018 than 2017,one year after CO_(2) enrichment began,whereas numbers declined in ambient plots.Enrichment with CO_(2) also increased the number of oak knopper galls(Andricus quercuscalicis Burgsdorf).We conclude that elevated CO_(2) increased the occurrence of acorns developing from flowers,but the putative benefit to mature acorn numbers may have been hidden by excessive pre-and/or post-dispersal predation.There was no evidence that elevated CO_(2) altered masting behaviour.展开更多
Acorns of Quercus aliena var. acuteserrata Maxim. are often predated by small mammals and birds in natural forests. These animals not only eat the acorns during the acorn ripening season, but also cache and hoard most...Acorns of Quercus aliena var. acuteserrata Maxim. are often predated by small mammals and birds in natural forests. These animals not only eat the acorns during the acorn ripening season, but also cache and hoard most of the remaining acorns on the forest floor in the soil for their future use. These buried acorns form the main seed resource for regeneration. Burying depth is potentially important for germination and for seedling development. The effects of burying depth on germination and seedling development in relation to acorn size were studied in an experiment, in which acorns were planted at 6 cm-, 12 cm- and 18 cm-depth. The experimental results showed that fewer acorns germinated as burying depth increased. From the deeply buried acorns fewer seedlings emerged at later time than from those acorns buried less deeply. They appeared to have more difficulties to emerge above-ground than die seedlings from shallowly buried acorns. The deeply buried acorns and their seedlings also appeared to be more susceptible to rot. Acorn size did not significantly affect germination and emergence of the seedlings. As early emerged seedlings had longer developmental periods in their first growing season, and therefore grew better than die late emerged seedlings, seedlings from die shallowly buried acorns took the advantage.展开更多
The investigation aimed at exploring whether 1) high contents of natural polyphenols from the diet can induce pigment accumulation in lymph nodes (LNs);2) if so, whether polyphenolic compounds and derivates can be use...The investigation aimed at exploring whether 1) high contents of natural polyphenols from the diet can induce pigment accumulation in lymph nodes (LNs);2) if so, whether polyphenolic compounds and derivates can be used as biological markers;3) and whether a lymph node from a specific anatomical region can be univocally identified, so as to be con sidered as a sentinel for the identification of the dietary origin of pigments. A paired match approach was used to switch 20 pigs (range of initial body weight, BW: 113 - 121 kg) to two experimental diets, for four weeks: ten pigs (pair housed) were fed with an experimental acorn based diet (acorns: 50% in the diet, as fed;total polyphenols, 78.1 g TP/Kg DM in the diet;tannic acid equivalent, 25.8 g TAE/kg DM);the remainder ten, received a pelleted complete diet for finishers (0% acorns in the diet). Daily feed intake in the last two weeks of the experimental feeding was recorded per pair of pigs in both groups of animals, showing an average intake of 610 mg TAE/kg BW/d. At an average final BW of between 127 to 137 kg, all pigs were slaughtered and LNs from different anatomical regions of the carcass were removed and analysed. At gross inspection, LNs from both groups displayed different grades of intensity and diffusion of pigmentation: a partial and incidental pigmentation was randomly detected in renal or sub-iliac LNs in the control group;a constant and uniform pigmentation of LNs was observed in acorns fed pigs: a dark brown staining diffused to the whole LN associated with a brownish colour of the muscles was found systematically. At light microscope intracytoplasmic granules were found in macrophages and dendritic cells from both groups, but, at confocal laser analysis, an intense auto-fluorescence was observed in medial-iliac LNs from the carcasses of acorn-fed pigs (green emission). However, intracellular sources of blue and green fluorescence at different wavelengths, likely due to tryptophan, indoleamine and derivates were also found in medial-iliac and inguinal LNs from the control group. A dietary origin was attributed to the different discoloration of LNs between the carcasses of the two groups: such acquired pigmentation is relevant in the left sub-iliac LN, but the confocal laser microscopic test to elicit auto-fluorescence of polyphenolic compounds (biological markers) displayed a 76.9% specificity, despite a 100% of sensitivity for the univocal identification of the carcass from acorn-fed pigs. Cranial sternal LNs resulted to suit the sentinel role in the distinction of carcass from acorns fed pigs at confocal laser microscopic analysis.展开更多
In the genus Quercus, regeneration by seed is reduced or absent in many species. The naturally protected area of the Sierra Fria, in Aguascalientes, Mexico contains forests that are fragmented and have been degraded d...In the genus Quercus, regeneration by seed is reduced or absent in many species. The naturally protected area of the Sierra Fria, in Aguascalientes, Mexico contains forests that are fragmented and have been degraded due to human activities. The oak populations in this region demonstrate a very restricted sexual regeneration, with five of the most abundant species of this genus: Quercuseduardii, Q. grisea, Q. potosina, Q. resinosa and Q. sideroxyla presenting low seedling recruitment. In this study we evaluated seed viability and the effect of seed size on the germination, growth and survival of the trees, with the aim of recommending restoration and conservation program management actions for these oak species. In 2005 and 2006, 5000 acorns of each species were collected and viability, germination and growth experiments were performed in the laboratory and greenhouse. We found high seed viability and significant size effect展开更多
Human living environment interacts with human behaviors.Environment to some degree determines human behaviors which in return reshape and sustain the dynamic environment.Taking Richard Jefferies' The Acorn Gathere...Human living environment interacts with human behaviors.Environment to some degree determines human behaviors which in return reshape and sustain the dynamic environment.Taking Richard Jefferies' The Acorn Gatherer as a case study,this paper makes an argument that the behaviors of the villagers in the story can be more adequately interpreted in view of the backward countryside environment,and the same is true with the author Richard Jefferies' non-interference in the omniscient third-person point of view in writing the story.It is Richard Jefferies' family environment that makes up his viewpoint of writing,reflecting his critical loving of the countryside,where lives boom and conventions are extremely followed.展开更多
The Acorn Gatherer by Richard Jefferies is an allegorical tragedy, in which a nameless boy, born out of wedlock, is viewed as a sort of icon of sin, and is ultimately driven to death by the rigid and unforgiving socia...The Acorn Gatherer by Richard Jefferies is an allegorical tragedy, in which a nameless boy, born out of wedlock, is viewed as a sort of icon of sin, and is ultimately driven to death by the rigid and unforgiving social conventions.展开更多
文摘Proline contents of parotid glands (PG) in pigs constantly increase after the inclusion of different amounts of ripe hulled acorns in the diet providing high polyphenols levels. The dose-response relationship was estimated on natural hydrolizable tannins (expressed as tannic acid equivalent TAE) amounts of 25.8 to 36.1 g TAE/kg DM in experimental diets. Macroscopic and histological morphometry of parotid glands greatly varied according to feed intake and dosages of TAE ingested. The PG response (hypertrophy grade) on acorns’ tannins content in the diet was positively correlated (R2 = 0.748): the response to the protein precipitating activity (PPA) of tannins consisted of a functional parotidomegaly (hypertrophy), 1.34 up to 3.55 folds than control PGs, following an oral dosage 0.596 up 1.72 TAE g·kg body weight·d-1 respectively, after one week exposure.
基金supported by the National Centre for Scientific Research,the University of Bourgogne Franche-Comté and the Regional Council of Franche-Comté
文摘We collected acorns from selected Quercus robur and Quercus petraea mother trees growing at sta- tions with different depths to the water table. We produced pairs of micro-cuttings from these single acorns. The obtained pairs of cuttings represented phenotypes of high similarity according to photosynthetic parameters. These pairs of cuttings were used to test the plasticity of response to contrasting water regimes. For each pair, one cutting was submitted to drought and the other was submitted to waterlogging. Drought response was recorded according to gas exchange traits （stomatal closure and water use effi- ciency）. The response to waterlogging was recorded according to the capacity to form hypertrophied lenticels and to maintain the CO2 assimilation rate. Intermediary phenotypes presenting both high water use efficiency and the capacity to develop hypertrophied lenticels were expected.
基金This study was supported by the National Natural Science Foundation of China(Nos.41872015,31770241,41820104002,and 41661134049)the grant of the Natural Environment Research Council of Research Councils UK(No.NE/P013805/1).
文摘Quercus is the largest genus within the Fagaceae and has a rich fossil record.Most of the fossil material is attributed to the subgenus Quercus based on leaves,pollen or rarely acorns and nuts.Fossil records of Q.section Cyclobalanopsis characterized by ring-cupped acorns are relatively few and especially those described based on nuts are scant.In this study,we described four new species of Quercus section Cyclobalanopsis based on mummified acorns and nuts:Q.paleodisciformis X.Y.Liu et J.H.Jin sp.nov.,Q.paleohui X.Y.Liu et J.H.Jin sp.nov.,Q.nanningensis X.Y.Liu et J.H.Jin sp.nov.and Q.yongningensis X.Y.Liu et J.H.Jin sp.nov.These species closely resemble the extant species Q.disciformis,Q.hui,Q.kerrii,and Q.dinghuensis.The occurrence of Q.section Cyclobalanopsis in the Oligocene stratum of Guangxi,South China,suggests that the section has diversified within its extant distribution center since the Oligocene.By combining records from other areas,we propose that the section first appeared in the middle Eocene of East Asia(Sino-Japan),has diversified in situ with a few elements scattering into West Asia and southern Europe since the Oligocene and Pliocene,respectively,and finally became restricted in East Asia since the Pleistocene.This indicates that the section originated and diversified in East Asia,before spreading into West Asia no later than the Oligocene and into southern Europe by the Pliocene.Subsequently it disappeared from South Europe and West Asia due to the appearance of the(summer dry)Mediterranean climate and widespread cooling during the Pleistocene.
文摘Oaks(Quercus spp.)provide an important food source for many wildlife species throughout the fall and winter.Most research evaluating oak masting patterns and the subsequent behavioral responses of wildlife focuses on the annual temporal scale.However,patterns in masting at the seasonal temporal scale may be important for wildlife behavior.We designed a study quantifying seasonal oak masting patterns of 3 oak species(water oak,Q.nigra;laurel oak,Q.laurifolia;and swamp chestnut oak,Q.michauxii)and linking those patterns to visitation and feeding behavior of 3 primary consumers(white-tailed deer,Odocoileus virginianus;gray squirrel,Sciurus carolinensis;and raccoon,Procyon lotor).We used seed traps to monitor the seasonal masting pattern of 205 trees in the fall of 2021 and 2022 and used camera traps concurrently to monitor wildlife behavior associated with a subset of 30 trees.Seasonal masting patterns differed between oak species both within a season and across years,and the timing of mast varied within oak species across years.White-tailed deer tended to visit swamp chestnut oak as the number of acorns increased and consumed their acorns.Gray squirrels and raccoons tended to visit laurel oak and consume water oak acorns with gray squirrels being more likely to consume as the number of acorns increased.Our results indicate that evaluating acorn production at multiple temporal scales may be necessary to fully understand oak masting relationships with wildlife.Furthermore,differences in wildlife behavior based on oak species may have important implications for oak regeneration.
基金supported by Future Trees TrustThe Patsy Wood Trust+2 种基金Scottish Forestry TrustAitchinson Tait TrustAction Oak
文摘Acorn production in oaks(Quercus spp.)shows considerable inter-annual variation,known as masting.The effects of pollen sourced from trees within or outside the stand on acorn production were investigated in pedunculate oak(Quercus robur L.)in an ancient mixed woodland during two moderate masting years.Comparisons were made between natural pollination,hand pollinations with out-of-stand pollen,in-stand pollen or a 1:1 combination of the two pollen sources,and for bagged flowers left unpollinated.After all treatments,>85%of the flowers or developing acorns were aborted between May and August of both years.When flowers were protected with pollen bags and no pollen added,no acorns were produced.In contrast,hand pollination with out-of-stand pollen produced the most acorns both years and significantly more than within-stand pollen or natural pollination in 2022.Hand pollination with out-of-stand or within-stand pollen provided significantly more acorns than natural pollination in 2023.In 2022,hand pollination with a 1:1 mixture of out-of-stand and within-stand pollen yielded an intermediate number of mature acorns between those for the out-of-stand and within-stand pollination treatments.The study provides clear evidence of maternal choice during acorn development in pedunculate oak and of the benefits of pollen supplementation.It also confirms that pedunculate oak is a fruit-maturation masting species;abortion of pollinated flowers and immature acorns determines a mast year(rather than the number of flowers produced)at this site.
基金This study was supported by funding from the Howard Hughes Medical Institute to M.A.S.the Natural Science Foundation of China(No.31172101)to X.F.Y.+3 种基金the National Basic Research Program of China(No.2007CB109100)to X.F.Y.the H.Fenner Research Fund of Wilkes University(M.A.S.)M.A.S also recognizes support of a Bullard Fellowship from Harvard Forest,Harvard University and the National Science Foundation(DEB 15556707)Support during final preparation of the manuscript was provided by the National Science Foundation Graduate Research Fellowship Program to A.W.B.and R.C.
文摘Fitness of parents and offspring is affected by offspring size.In oaks(Quercus spp.),acorns vary considerably in size across,and within,species.Seed size influences dispersal and establishment of oaks,but it is not known whether size imparts tolerance to seed predators.Here,we examine the relative extent to which cotyledon size serves as both a means for sustaining partial consumption and energy reserves for developing seedlings during early stages of establishment.Acorns of 6 oak species were damaged to simulate acorn predation by vertebrate and invertebrate seed predators.Seedling germination/emergence and growth rates were used to assess seedling performance.We predicted that if cotyledons are important for dispersal,acorns should show tolerance to partial seed consumption.Alternatively,if the cotyledon functions primarily as an energy reserve,damage should significantly influence seedling performance.Acorns of each species germinated and produced seedlings even after removing>50%of the cotyledon.Seed mass explained only some of the variation in performance.Within species,larger acorns performed better than smaller acorns when damaged.Undamaged acorns performed as well or better than damaged acorns.There was no pattern among individual species with increasing amounts of damage.In some species,simulated invertebrate damage resulted in the poorest performance,suggesting alternative strategies of oaks to sustain damage.Large cotyledons in acorns may be important for attracting seed dispersers and sustaining partial damage,while also providing energy to young seedlings.Success of oak establishment may follow from the resilience of acorns to sustain damage at an early stage.
基金supported in part by“The Fundamental Research Funds for the Central Universities”(BLX202218).
文摘The study investigated the effects of ethanol precipitation on the polysaccharide components obtained from 3 different oak acorns.The variables factors were ethanol precipitation times(1×or 2×),tree species(Quercus variabilis,Quercus aliena,Quercus dentata)and raw materials(whole acorn fruit or kernels).Through detections of acorn polysaccharide concentrations from different species and components analyses,we found that the second ethanol precipitation had a better extraction effect,and acorn polysaccharides were proved to be mainly composed of glucose,galacturonic acid,arabinose and galactose.Compared with other groups,the highest content of polysaccharides was proved to be extracted from Q.variabilis kernels,thus,acorn kernels should be suggested as the proper material for the extraction of acorn polysaccharides.Interestingly,acorn polysaccharides functionally alleviated liver and kidney damages in type 2 diabetes mice,they also had noticeable hypoglycemic effects and regulated insulin secretion,particularly in combination with metformin and D-mannuronic acid.
文摘专注于中短期卷筒纸胶印业务的印刷企业Acorn Web Offset近期投资购置了一台全新的Komori G37 Lithrone单张纸胶印机,用以替换公司现有的封面印刷设备。Acorn Web Offset公司在位于西约克郡诺曼顿的工厂拥有约130名员工,这台全新引进的印刷机计划于2025年最后一个季度正式投入使用,届时它将助力公司封面印刷的生产效率提升30%,并有效减少纸张浪费和能源消耗。
基金The authors recognize financial support of the US National Science Foundation(DEB-0642434 and DEB-0642504,RS,MS,NL,the Howard Hughes Medical Institute(AB,MS)The Fenner Endowment of the Department of Biology of Wilkes University(AB,MK,MS).
文摘Studies from both tropical and temperate systems show that scatter-hoarding rodents selectively disperse larger seeds farther from their source than smaller seeds,potentially increasing seedling establishment in larger-seeded plants.Size-biased dispersal is evident in many oaks(Quercus)and is true both across and within species.Here,we predict that intraspecifc variation in seed size also influences acorn dispersal by the Blue Jay(Cyanocitta cristata Linnaeus),but in an opposite manner.Blue Jays are gape-limited and selectively disperse smaller acorn species(e.g.pin oaks[Quercus palustris Münchh]),but often carry several acorns in their crop during a single dispersal event.We predict that jays foraging on smaller acorns will load more seeds per trip and disperse seeds to greater distances than when single acorns are carried in the bill.To test this,we presented free-ranging Blue Jays with pin oak acorns of different sizes over a 2-year period.In each of 16 experimental trials,we monitored the birds at a feeding station with remote cameras and determined the number of acorns removed and the distance acorns were dispersed when cached.Jays were significantly more likely to engage in multiple seed loading with smaller seeds in both years of the study.During the second year,these smaller acorns were dispersed farther than larger acorns,and during the first year,larger acorns were dispersed farther,revealing an inconsistent response to seed size during our study.We suggest that in some circumstances,multiple seed loading by Blue Jays may favor dispersal in some plant species.
基金supported by Future Trees Trust,The Patsy Wood Trust,Scottish Forestry Trust,Aitchinson Tait Trust,and Action Oak for fundingsupport from the UK Natural Environment Research Council (NE/S015833/1 (QUINTUS))+1 种基金support from the JABBS Trust,Norbury Park Estate,The John Horseman Trust,Ecological Continuity Trust,and the University of BirminghamAccess to BIFoR Core Data was funded by Royal Society University Research Fellowship URFR1191326
文摘Acorn production in oak(Quercus spp.)shows considerable inter-annual variation,known as masting,which provides a natural defence against seed predators but a highly-variable supply of acorns for uses such as in commercial tree planting each year.Anthropogenic emissions of greenhouse gases have been very widely reported to influence plant growth and seed or fruit size and quantity via the‘fertilisation effect’that leads to enhanced photosynthesis.To examine if acorn production in mature woodland communities will be affected by further increase in CO_(2),the contents of litter traps from a Free Air Carbon Enrichment(FACE)experiment in deciduous woodland in central England were analysed for numbers of flowers and acorns of pedunculate oak(Quercus robur L.)at different stages of development and their predation levels under ambient and elevated CO_(2) concentrations.Inter-annual variation in acorn numbers was considerable and cyclical between 2015 and 2021,with the greatest numbers of mature acorns in 2015,2017 and 2020 but almost none in 2018.The numbers of flowers,enlarged cups,immature acorns,empty acorn cups,and galls in the litter traps also varied amongst years;comparatively high numbers of enlarged cups were recorded in 2018,suggesting Q.robur at this site is a fruit maturation masting species(i.e.,the extent of abortion of pollinated flowers during acorn development affects mature acorn numbers greatly).Raising the atmospheric CO_(2) concentration by 150μL L^(−1),from early 2017,increased the numbers of immature acorns,and all acorn evidence(empty cups+immature acorns+mature acorns)detected in the litter traps compared to ambient controls by 2021,but did not consistently affect the numbers of flowers,enlarged cups,empty cups,or mature acorns.The number of flowers in the elevated CO_(2) plots’litter traps was greater in 2018 than 2017,one year after CO_(2) enrichment began,whereas numbers declined in ambient plots.Enrichment with CO_(2) also increased the number of oak knopper galls(Andricus quercuscalicis Burgsdorf).We conclude that elevated CO_(2) increased the occurrence of acorns developing from flowers,but the putative benefit to mature acorn numbers may have been hidden by excessive pre-and/or post-dispersal predation.There was no evidence that elevated CO_(2) altered masting behaviour.
文摘Acorns of Quercus aliena var. acuteserrata Maxim. are often predated by small mammals and birds in natural forests. These animals not only eat the acorns during the acorn ripening season, but also cache and hoard most of the remaining acorns on the forest floor in the soil for their future use. These buried acorns form the main seed resource for regeneration. Burying depth is potentially important for germination and for seedling development. The effects of burying depth on germination and seedling development in relation to acorn size were studied in an experiment, in which acorns were planted at 6 cm-, 12 cm- and 18 cm-depth. The experimental results showed that fewer acorns germinated as burying depth increased. From the deeply buried acorns fewer seedlings emerged at later time than from those acorns buried less deeply. They appeared to have more difficulties to emerge above-ground than die seedlings from shallowly buried acorns. The deeply buried acorns and their seedlings also appeared to be more susceptible to rot. Acorn size did not significantly affect germination and emergence of the seedlings. As early emerged seedlings had longer developmental periods in their first growing season, and therefore grew better than die late emerged seedlings, seedlings from die shallowly buried acorns took the advantage.
文摘The investigation aimed at exploring whether 1) high contents of natural polyphenols from the diet can induce pigment accumulation in lymph nodes (LNs);2) if so, whether polyphenolic compounds and derivates can be used as biological markers;3) and whether a lymph node from a specific anatomical region can be univocally identified, so as to be con sidered as a sentinel for the identification of the dietary origin of pigments. A paired match approach was used to switch 20 pigs (range of initial body weight, BW: 113 - 121 kg) to two experimental diets, for four weeks: ten pigs (pair housed) were fed with an experimental acorn based diet (acorns: 50% in the diet, as fed;total polyphenols, 78.1 g TP/Kg DM in the diet;tannic acid equivalent, 25.8 g TAE/kg DM);the remainder ten, received a pelleted complete diet for finishers (0% acorns in the diet). Daily feed intake in the last two weeks of the experimental feeding was recorded per pair of pigs in both groups of animals, showing an average intake of 610 mg TAE/kg BW/d. At an average final BW of between 127 to 137 kg, all pigs were slaughtered and LNs from different anatomical regions of the carcass were removed and analysed. At gross inspection, LNs from both groups displayed different grades of intensity and diffusion of pigmentation: a partial and incidental pigmentation was randomly detected in renal or sub-iliac LNs in the control group;a constant and uniform pigmentation of LNs was observed in acorns fed pigs: a dark brown staining diffused to the whole LN associated with a brownish colour of the muscles was found systematically. At light microscope intracytoplasmic granules were found in macrophages and dendritic cells from both groups, but, at confocal laser analysis, an intense auto-fluorescence was observed in medial-iliac LNs from the carcasses of acorn-fed pigs (green emission). However, intracellular sources of blue and green fluorescence at different wavelengths, likely due to tryptophan, indoleamine and derivates were also found in medial-iliac and inguinal LNs from the control group. A dietary origin was attributed to the different discoloration of LNs between the carcasses of the two groups: such acquired pigmentation is relevant in the left sub-iliac LN, but the confocal laser microscopic test to elicit auto-fluorescence of polyphenolic compounds (biological markers) displayed a 76.9% specificity, despite a 100% of sensitivity for the univocal identification of the carcass from acorn-fed pigs. Cranial sternal LNs resulted to suit the sentinel role in the distinction of carcass from acorns fed pigs at confocal laser microscopic analysis.
文摘In the genus Quercus, regeneration by seed is reduced or absent in many species. The naturally protected area of the Sierra Fria, in Aguascalientes, Mexico contains forests that are fragmented and have been degraded due to human activities. The oak populations in this region demonstrate a very restricted sexual regeneration, with five of the most abundant species of this genus: Quercuseduardii, Q. grisea, Q. potosina, Q. resinosa and Q. sideroxyla presenting low seedling recruitment. In this study we evaluated seed viability and the effect of seed size on the germination, growth and survival of the trees, with the aim of recommending restoration and conservation program management actions for these oak species. In 2005 and 2006, 5000 acorns of each species were collected and viability, germination and growth experiments were performed in the laboratory and greenhouse. We found high seed viability and significant size effect
文摘Human living environment interacts with human behaviors.Environment to some degree determines human behaviors which in return reshape and sustain the dynamic environment.Taking Richard Jefferies' The Acorn Gatherer as a case study,this paper makes an argument that the behaviors of the villagers in the story can be more adequately interpreted in view of the backward countryside environment,and the same is true with the author Richard Jefferies' non-interference in the omniscient third-person point of view in writing the story.It is Richard Jefferies' family environment that makes up his viewpoint of writing,reflecting his critical loving of the countryside,where lives boom and conventions are extremely followed.
文摘The Acorn Gatherer by Richard Jefferies is an allegorical tragedy, in which a nameless boy, born out of wedlock, is viewed as a sort of icon of sin, and is ultimately driven to death by the rigid and unforgiving social conventions.
