Ten physical and environmental variables collected from an on-the-go soil sensor at two field sites (MF3E and MF11S) in Mississippi, USA, were analyzed to assess soil variability and the interrelationships among the m...Ten physical and environmental variables collected from an on-the-go soil sensor at two field sites (MF3E and MF11S) in Mississippi, USA, were analyzed to assess soil variability and the interrelationships among the measurements. At MF3E, moderate variability was observed in apparent electrical conductivity shallow (ECas), slope, and ECa ratio measurements, with coefficients of variation ranging from 20% to 27%. In contrast, MF11S exhibited higher variability, particularly in ECas and ECad (deep) measurements, which exceeded 30% in their coefficient of variation values, indicating significant differences in soil composition and moisture content. Correlation analysis revealed strong positive relationships between the near-infrared-to-red ratio and red reflectance (r = 0.897***) soil values at MF3E. MF11S demonstrated a strong negative correlation between ECas and ECad readings with the x-coordinate (r ***). Scatter plots and fitted models illustrated the complexity of relationships, with many showing nonlinear trends. These findings emphasize the need for continuous monitoring and advanced modeling to understand the dynamic nature of soil properties and their implications for agricultural practices. Future research should explore the underlying mechanisms driving variability in the soil characteristics to enhance soil management strategies at the study sites.展开更多
Studies on plant diversity are usually based on the total number of species in a community.However,few studies have examined species richness(SR)of different plant life forms in a community along largescale environmen...Studies on plant diversity are usually based on the total number of species in a community.However,few studies have examined species richness(SR)of different plant life forms in a community along largescale environmental gradients.Particularly,the relative importance(RIV)of different plant life forms in a community and how they vary with environmental variables are still unclear.To fill these gaps,we determined plant diversity of ephemeral plants,annual herbs,perennial herbs,and woody plants from 187 sites across drylands in China.The SR patterns of herbaceous plants,especially perennial herbs,and their RIV in plant communities increased with increasing precipitation and soil nutrient content;however,the RIV of annual herbs was not altered along these gradients.The SR and RIV of ephemeral plants were affected mainly by precipitation seasonality.The SR of woody plants had a unimodal relationship with air temperature and exhibited the highest RIV and SR percentage in plant communities under the harshest environments.An obvious shift emerged in plant community composition,SR and their critical impact factors at 238.5 mm of mean annual precipitation(MAP).In mesic regions(>238.5 mm),herbs were the dominant species,and the SR displayed a relatively slow decreasing rate with increasing aridity,which was mediated mainly by MAP and soil nutrients.In arid regions(<238.5 mm),woody plants were the dominant species,and the SR displayed a relatively fast decreasing rate with increasing aridity,which was mediated mainly by climate variables,especially precipitation.Our findings highlight the importance of comparative life form studies in community structure and biodiversity,as their responses to gradients differed substantially on a large scale.展开更多
Adelphocoris suturalis is a polyphagous pest that is increasingly causing severe economic damage due to more frequent outbreaks.The development of non-target resistance to commercial Bacillus thuringiensis(Bt)cotton h...Adelphocoris suturalis is a polyphagous pest that is increasingly causing severe economic damage due to more frequent outbreaks.The development of non-target resistance to commercial Bacillus thuringiensis(Bt)cotton has further exacerbated its pest status and amplified the need for more sustainable methods of control.RNA interference(RNAi)-based pest management strategies,such as root soaking and transgenic plants that express dsRNAs,have proven to be reliable,eco-friendly pest control strategies.To identify new RNAi targets for potential A.suturalis population control,we investigated the target of rapamycin(TOR)signaling pathway.A critical role for this pathway in A.suturalis reproductive regulation was suggested by pharmacological analyses.Subsequent RNAi-mediated knockdown of the A.suturalis TOR pathway genes TOR,Ras homolog enriched in the brain(Rheb),and ribosomal S6 kinase(S6K)reduced fertility.Moreover,a spray-induced and nanocarrier-delivered gene silencing(SI-NDGS)system targeting TOR successfully suppressed ovarian development,which demonstrates its effectiveness as a pest control target.These results provide a critical foundation for understanding reproductive regulation in A.suturalis and introduce new candidates for RNAi-based A.suturalis management.展开更多
Intraspecific genetic variance and gene flow can support the adaptive evolution of species challenged by climate shifts or novel environmental conditions.Less well understood is how genome organization and gene flow i...Intraspecific genetic variance and gene flow can support the adaptive evolution of species challenged by climate shifts or novel environmental conditions.Less well understood is how genome organization and gene flow interact in closely related species during evolutionary divergence and differentiation.Here we conducted genomic footprint analyses to determine how three species of Pterocarya(P.stenoptera,P.hupehensis,and P.macroptera),which are sympatric but occupy different elevational niches,adapted to the heterogeneous environment of the Qinling-Daba Mountains,China.We identified candidate genes for environmental adaptation(i.e.,PIEZO1,WRKY39,VDAC3,CBL1,and RAF),and also identified regions of gene introgression between P.hupehensis and P.macroptera that show lower genetic load and higher genetic diversity than the rest of their genomes.The same introgressed regions are notably situated in areas of minimal genetic divergence yet they are characterized by elevated recombination rates.We also identified candidate genes within these introgressed regions related to environmental adaptation(TPLC2,CYCH;1,LUH,bHLH112,GLX1,TLP-3,and ABC1).Our findings have thus clarified the important role of gene flow in ecological adaptation and revealed genomic signatures of past introgression.Together,these findings provide a stronger theoretical basis for understanding the ecological adaptation and conservation of Quaternary relict woody plants in East Asia.展开更多
Understanding the phenology and productivity of Populus species is crucial for effective management and conservation strategies amid climate change.We investigated leaf budbreak timing,susceptibility to cold damage,le...Understanding the phenology and productivity of Populus species is crucial for effective management and conservation strategies amid climate change.We investigated leaf budbreak timing,susceptibility to cold damage,leaf dynamics,and biomass production of 168 Populus genotypes with diverse provenances in the southeastern United States.Our study revealed significant variation in budbreak timing across different taxa and years,with genotypes inheriting traits adapted to their parents’local climates.Temperature emerged as a key factor triggering budbreak,while leaf development depended on other environmental cues such as photoperiod.Notably,budbreak occurred approximately 20 days earlier in 2023 compared to 2022 due to higher accumulated degree days(ADDs).Short-rotation-coppice(SRC)management delayed budbreak by five to ten days.Cold damage was significant in 2023,particularly for genotypes from northern provenances and those with P.maximowiczii parentage.Severe damage was also observed in eastern cottonwood(Populus deltoides×Populus deltoides(D×D))genotypes,despite most having southeastern US parentages.Leaf dynamics,including leaf duration and leaf area index(LAI),varied across taxa and sites,with earlier budbreak correlating with extended growing seasons and increased LAI.Biomass production was intricately linked to phenological events,with earlier budbreak leading to increased biomass production and greater susceptibility to cold damage.Our findings highlight the importance of genetics,environment,and coppicing management in understanding and managing Populus phenology and biomass production.These insights provide valuable guidance for developing effective breeding,conservation,and management strategies for Populus species in the context of climate change.展开更多
Hydraulic vulnerability,the sensitivity of xylem embolism to water stress,is a major determinant trait associated with conifer mortality.This study investigated branch P50(50%hydraulic conductivity loss)of adult and j...Hydraulic vulnerability,the sensitivity of xylem embolism to water stress,is a major determinant trait associated with conifer mortality.This study investigated branch P50(50%hydraulic conductivity loss)of adult and juvenile ponderosa pines across multiple locations in the southwestern United States(SWUS),and examined relationships between P50 and climatic conditions,soil properties and forest management.Juvenile ponderosa pines had significantly more negative P50 values than adults on average.Both age groups exhibited a latitudinal pattern in P50 associated with regional climate conditions.Across the SWUS,juvenile P50 was positively correlated with growing season precipitation and temperature,and negatively correlated with soil pH and clay content.In some cases,significant differences in juvenile P50 between SWUS locations were associated with growing season moisture deficit,whereas other significant differences were less attributable to climate and may attest to potential genetic variation between populations.Climate variation,soil properties and population-level acclimation and/or adaptation may all influence the hydraulic vulnerability of juvenile ponderosa pines in the SWUS,promoting differences in stress tolerance of ponderosa pine forests across the region.展开更多
The future distribution of invading species depends on the climate space available and certain life history traits that facilitate invasion.Here,to predict the spread potential of plant species introduced in North Ame...The future distribution of invading species depends on the climate space available and certain life history traits that facilitate invasion.Here,to predict the spread potential of plant species introduced in North America north of Mexico(NAM),we compiled distribution and life history data(i.e.,seed size,life form,and photosynthetic pathways)for 3021 exotic plant species introduced to NAM.We comparatively examined the species’range size and climate space in both native and exotic regions and the role of key life history traits.We found that large climate space for most exotic plants is still available in NAM.The range sizes in global exotic regions could better predict the current range sizes in NAM than those in global native regions or global native plus exotic regions.C3 species had larger ranges on average than C4 and CAM plants,and herbaceous species consistently showed stronger relationships in range size between native and exotic regions than woody species,as was the case within the C3 species group.Seed size was negatively related to range size both in native regions and in NAM.However,seed size surprisingly showed a positive correlation with global exotic range size and no correlation with the current actual global(native plus exotic)range size.Our findings underline the importance of species’native distribution and life history traits in predicting the spread of exotic species.Future studies should continue to identify potential climate space and use underappreciated species traits to better predict species invasions under changing climate.展开更多
Forest ecosystems can be characterized by a set of catenas arranged along the slope in mountainous areas as these affect microhabitat features,which in turn influence soil properties.Heretofore,few studies have examin...Forest ecosystems can be characterized by a set of catenas arranged along the slope in mountainous areas as these affect microhabitat features,which in turn influence soil properties.Heretofore,few studies have examined how topographic variables affect soil properties and quality in semiarid regions.This study aimed to provide important insights into how catena position and shape influence soil properties,soil quality,and their interrelationships in a semiarid protected oak forest in western Iran.Basic soil properties were measured in the laboratory.In addition,the soil quality index(SQI)was calculated at different topographic positions along both convex(Λ-shaped)and concave(V-shaped)catenas at two soil depths(0-15 and 15-30 cm).The findings indicated that soil organic carbon and total nitrogen declined in the lower depth in both V-andΛ-shaped catenas and at all catena positions.The lowest porosity was observed in the lower depth at toeslope positions(TS)of both catenas.Substrate-induced respiration(SIR),microbial biomass carbon(MBC),and basal respiration(BR)were higher in the upper depths at TS positions on V-shaped catenas than onΛ-shaped catenas.These biological indices were consistently higher in the upper depths than in the lower depths across all positions of both catenas.SQI had the highest values at TS positions on both catenas and in the upper depths across all positions.Pearson correlations between soil properties indicated that SQI was most strongly and positively correlated with biological properties in both catenas.The nutrient levels,microbial activity,and soil porosity in both catena shapes and at both soil depths displayed a relatively downward trend with increasing elevation from toeslope to summit positions.The results showed that catena topographic sequence shape and position affected most of the soil properties,providing evidence of the important role of topography in creating pedodiversity in oak forest ecosystems.展开更多
Background GOSSYM is a mechanistic,process-based cotton model that can simulate cotton crop growth and development,yield,and fiber quality.Its fiber quality module was developed based on controlled experiments explici...Background GOSSYM is a mechanistic,process-based cotton model that can simulate cotton crop growth and development,yield,and fiber quality.Its fiber quality module was developed based on controlled experiments explicitly conducted on the Texas Marker^(-1)(TM1)variety,potentially making its functional equations more aligned with this cultivar.To assess the model’s broader applicability,this study analyzed fiber quality data from 40 upland cotton cultivars,including TM1.The measured fiber quality from all cultivars was then compared with the modelsimulated fiber quality.Results Among the 40 upland cultivars,fiber strength varied from 28.4 cN·tex^(-1) to 34.6 cN·tex^(-1),fiber length ranged from 27.1 mm to 33.3 mm,micronaire value ranged from 2.7 to 4.6,and length uniformity index varied from 82.3%to 85.5%.The model simulated fiber quality closely matched the measured values for TM1,with the absolute percentage error(APE)being less than 0.92%for fiber strength,fiber length,and length uniformity index and 4.7%for micronaire.However,significant differences were observed for the other cultivars.The Pearson correlation coefficient(r)between the measured and simulated values was negative for all fiber quality traits,and Wilmotts’s index of agreement(WIA)was below 0.45,indicating a strong model bias toward TM1 without incorporating cultivar-specific parameters.After incorporating cultivar-specific parameters,the model’s performance improved significantly,with an average r-value of 0.84 and WIA of 0.88.Conclusions The adopted methodology and estimated cultivar-specific parameters improved the model’s simulation accuracy.This approach can be applied to newer cotton cultivars,enhancing the GOSSYM model’s utility and its applicability for agricultural management and policy decisions.展开更多
Wheat grains contain various bioactive substances,of which,condensed tannins(CT)are polymeric flavan-3-ols that accumulate in wheat seed coat influencing the end-use quality and nutritional value.However,the genetic a...Wheat grains contain various bioactive substances,of which,condensed tannins(CT)are polymeric flavan-3-ols that accumulate in wheat seed coat influencing the end-use quality and nutritional value.However,the genetic architecture underlying CT biosynthesis in wheat grain remains unclear.Here,we studied the deposition and genetic regulation of CT in wheat grains,and found that CT deposited specifically in the testa layer of red-grained wheat as catechin-and epicatechin-formed polymers.Genome-wide association study identified 22 genetic loci affecting CT content,one of which,TaTAN,a single dominant gene controlling CT presence,was mapped to chromosome 3A in a segregation population.Further pan-genome analysis,transcriptome profiling and ethyl methanesulfonate induced mutants sequencing revealed a R2R3-MYB transcription factor,TaMYB10-3A,as the causal gene.Three loss-of-function alleles in TaMYB10-3A caused by large fragment inversion-deletion and insertion were identified which abolish both CT deposition and red pigmentation,demonstrating the pleiotropic effect of TaMYB10-3A on CT presence and grain color.TaMYB10-3A directly trans-activates core flavonoid genes such as chalcone synthase and dihydroflavonol 4-reductase to initiate CT biosynthesis.Our investigation provides a comprehensive understanding of CT presence in wheat grains and lays a solid foundation for manipulating CT metabolites to improve wheat grain end-use quality and nutrition values in wheat.展开更多
Foliar resorption is a principal nutrient conservation mechanism in terrestrial vegetation that could be sensitive to ongoing changes in climate and atmospheric nitrogen(N)deposition.We quantified N resorption in nort...Foliar resorption is a principal nutrient conservation mechanism in terrestrial vegetation that could be sensitive to ongoing changes in climate and atmospheric nitrogen(N)deposition.We quantified N resorption in northern hardwood forests along an elevation gradient of decreasing temperature and increasing soil N availability to evaluate how this critical nutrient cycling process can be expected to respond to global and regional environmental changes.Foliar N resorption proficiency(NRP)increased significantly at lower elevations for both sugar maple and American beech,the dominant species in these forests.Foliar N resorption efficiency(NRE)also decreased with increasing elevation,but only in one year.Both species exhibited strong negative relationships between NRP and soil N availability.Thus,we anticipate that with climate warming and decreasing N inputs,northern hardwood forests can be expected to exhibit stronger N conservation via foliar resorption.Both species also exhibited strong correlations between resorption efficiency of N and C,but resorption of both elements was much greater for beech than sugar maple,suggesting contrasting mechanisms of nutrient conservation between these two widespread species.展开更多
A growing recognition that uneven-aged silviculture can offer multiple benefits to forested ecosystems has encouraged some landowners in the southern region of the United States to convert even-aged pine stands into m...A growing recognition that uneven-aged silviculture can offer multiple benefits to forested ecosystems has encouraged some landowners in the southern region of the United States to convert even-aged pine stands into multi-aged stands.For shade-intolerant pines of the southern United States,however,few studies have examined residual tree growth following silvicultural treatments that convert even-aged stands to multi-aged stands.Understanding the growth response of residual trees to different kinds of stand conversion treatments is critical to stand development and sustainability,as trees must be recruited into larger size classes during the conversion process to develop the desired stand structure and maintain productivity.In this study,we utilized a replicated,long-term silvicultural experimental trial in the southeastern United States to assess the effects of two cutting treatments(dispersed"single tree cutting"that created small canopy gaps and the"patch cutting"that created 0.1-0.8ha patch openings)and an uncut control on the 14-year growth(~cutting cycle length)of residual longleaf pine(Pinus palustris Mill.)trees.We found that tree growth,measured as mean basal area increment(BAI),was significantly higher following patch cutting(mean BAI of 16.97cm^(2))compared to both the single tree cutting(13.33cm^(2))and the uncut control(12.68cm^(2))(p<0.001).In patch cutting,the size of the patch opening,the location of trees surrounding the patch opening,and the position of the tree canopy all had a significant effect on BAI.Trees surrounding patch openings of 0.4ha exhibited greater growth,with a mean BAI of 19.24cm^(2),compared to those surrounding 0.1 and 0.8ha patch openings,which had mean BAI values of 15.89 and 15.71cm^(2),respectively(p<0.001).The position of a tree around the patch opening also influenced tree growth,as residual trees more to the North,South,and East sides exhibited significantly higher mean BAI than trees on the West side of the patch openings(p<0.001).However,distance from the patch opening border did not significantly affect the mean BAI(p=0.522).In all treatments,dominant and co-dominant trees exhibited higher BAI than intermediate and overtopped trees,indicating that tree canopy position significantly influenced tree growth(p<0.001).Understanding how residual trees grow after these silvicultural treatments is crucial for thoroughly assessing their efficacy with longleaf pine.This study's findings will enhance our understanding of stand dynamics during stand conversion and help land managers anticipate the growth of longleaf pine into larger size categories after single tree and patch cuttings.展开更多
As interest in tropical forest restoration accelerates,understanding its hydrological implications is increasingly urgent.While concerns persist that reforestation will reduce annual water yields—particularly in drie...As interest in tropical forest restoration accelerates,understanding its hydrological implications is increasingly urgent.While concerns persist that reforestation will reduce annual water yields—particularly in drier climates—we highlight conditions under which forest landscape restoration(FLR)can improve seasonal water availability,especially during the dry season.We examine the trade-off between increased vegetation water use(“pumping”)and enhanced infiltration and subsurface retention(“sponging”)following forestation of degraded lands,the recovery of vegetation's ability to capture“occult”precipitation(fog)in specific coastal and montane settings,and the role of forest cover in enhancing moisture recycling and transport at multiple scales.A pan-tropical sensitivity analysis shows that in degraded landscapes with deep soils and pronounced rainfall seasonality,infiltration gains following forestation can offset or exceed evaporative losses,thereby supporting groundwater recharge and increasing dry-season flows in approximately 10%of cases,with an additional 8%showing near-neutral(slightly negative)outcomes.These findings challenge the assumption that forestation uniformly reduces water availability and underscore the need to prioritize dry-season flow recovery—rather than annual water yield—as a central hydrological goal of FLR.We call for trans-disciplinary research and long-term monitoring to inform forest restoration strategies,particularly in seasonally dry regions where water scarcity is most acute.展开更多
文摘Ten physical and environmental variables collected from an on-the-go soil sensor at two field sites (MF3E and MF11S) in Mississippi, USA, were analyzed to assess soil variability and the interrelationships among the measurements. At MF3E, moderate variability was observed in apparent electrical conductivity shallow (ECas), slope, and ECa ratio measurements, with coefficients of variation ranging from 20% to 27%. In contrast, MF11S exhibited higher variability, particularly in ECas and ECad (deep) measurements, which exceeded 30% in their coefficient of variation values, indicating significant differences in soil composition and moisture content. Correlation analysis revealed strong positive relationships between the near-infrared-to-red ratio and red reflectance (r = 0.897***) soil values at MF3E. MF11S demonstrated a strong negative correlation between ECas and ECad readings with the x-coordinate (r ***). Scatter plots and fitted models illustrated the complexity of relationships, with many showing nonlinear trends. These findings emphasize the need for continuous monitoring and advanced modeling to understand the dynamic nature of soil properties and their implications for agricultural practices. Future research should explore the underlying mechanisms driving variability in the soil characteristics to enhance soil management strategies at the study sites.
基金supported by the National Key Research and Development Program of China(2023YFF0805602)National Natural Science Foundation of China(32225032,32001192,32271597)+1 种基金the Innovation Base Project of Gansu Province(2021YFF0703904)the Science and Technology Program of Gansu Province(24JRRA515,22JR5RA525,23JRRA1157).
文摘Studies on plant diversity are usually based on the total number of species in a community.However,few studies have examined species richness(SR)of different plant life forms in a community along largescale environmental gradients.Particularly,the relative importance(RIV)of different plant life forms in a community and how they vary with environmental variables are still unclear.To fill these gaps,we determined plant diversity of ephemeral plants,annual herbs,perennial herbs,and woody plants from 187 sites across drylands in China.The SR patterns of herbaceous plants,especially perennial herbs,and their RIV in plant communities increased with increasing precipitation and soil nutrient content;however,the RIV of annual herbs was not altered along these gradients.The SR and RIV of ephemeral plants were affected mainly by precipitation seasonality.The SR of woody plants had a unimodal relationship with air temperature and exhibited the highest RIV and SR percentage in plant communities under the harshest environments.An obvious shift emerged in plant community composition,SR and their critical impact factors at 238.5 mm of mean annual precipitation(MAP).In mesic regions(>238.5 mm),herbs were the dominant species,and the SR displayed a relatively slow decreasing rate with increasing aridity,which was mediated mainly by MAP and soil nutrients.In arid regions(<238.5 mm),woody plants were the dominant species,and the SR displayed a relatively fast decreasing rate with increasing aridity,which was mediated mainly by climate variables,especially precipitation.Our findings highlight the importance of comparative life form studies in community structure and biodiversity,as their responses to gradients differed substantially on a large scale.
基金supported by the National Natural Science Foundation of China(32072428)。
文摘Adelphocoris suturalis is a polyphagous pest that is increasingly causing severe economic damage due to more frequent outbreaks.The development of non-target resistance to commercial Bacillus thuringiensis(Bt)cotton has further exacerbated its pest status and amplified the need for more sustainable methods of control.RNA interference(RNAi)-based pest management strategies,such as root soaking and transgenic plants that express dsRNAs,have proven to be reliable,eco-friendly pest control strategies.To identify new RNAi targets for potential A.suturalis population control,we investigated the target of rapamycin(TOR)signaling pathway.A critical role for this pathway in A.suturalis reproductive regulation was suggested by pharmacological analyses.Subsequent RNAi-mediated knockdown of the A.suturalis TOR pathway genes TOR,Ras homolog enriched in the brain(Rheb),and ribosomal S6 kinase(S6K)reduced fertility.Moreover,a spray-induced and nanocarrier-delivered gene silencing(SI-NDGS)system targeting TOR successfully suppressed ovarian development,which demonstrates its effectiveness as a pest control target.These results provide a critical foundation for understanding reproductive regulation in A.suturalis and introduce new candidates for RNAi-based A.suturalis management.
基金supported by the National Natural Science Foundation of China(32370386,32070372,and 32200295)Science Foundation for Distinguished Young Scholars of Shaanxi Province(2023-JC-JQ-22)+4 种基金Basic Research Project of Shaanxi Academy of Fundamental Science(22JHZ005)Shaanxi Key Research and Development Program(2024NC-YBXM-064)Science and Technology Program of Shaanxi Academy of Science(2023K-49,2023K-26,and 2019K-06)Shaanxi Forestry Science and Technology Innovation Key Project(SXLK2023-02-20)Qinling Hundred Talents Project of Shaanxi Academy of Science(Y23Z619F17).
文摘Intraspecific genetic variance and gene flow can support the adaptive evolution of species challenged by climate shifts or novel environmental conditions.Less well understood is how genome organization and gene flow interact in closely related species during evolutionary divergence and differentiation.Here we conducted genomic footprint analyses to determine how three species of Pterocarya(P.stenoptera,P.hupehensis,and P.macroptera),which are sympatric but occupy different elevational niches,adapted to the heterogeneous environment of the Qinling-Daba Mountains,China.We identified candidate genes for environmental adaptation(i.e.,PIEZO1,WRKY39,VDAC3,CBL1,and RAF),and also identified regions of gene introgression between P.hupehensis and P.macroptera that show lower genetic load and higher genetic diversity than the rest of their genomes.The same introgressed regions are notably situated in areas of minimal genetic divergence yet they are characterized by elevated recombination rates.We also identified candidate genes within these introgressed regions related to environmental adaptation(TPLC2,CYCH;1,LUH,bHLH112,GLX1,TLP-3,and ABC1).Our findings have thus clarified the important role of gene flow in ecological adaptation and revealed genomic signatures of past introgression.Together,these findings provide a stronger theoretical basis for understanding the ecological adaptation and conservation of Quaternary relict woody plants in East Asia.
基金funded by the USDA National Institute of Food and Agriculture(USDA-NIFA)through the APPS grant(Advancing Populus Pathways in the Southeast,2018-68005-27636)United States Department of Energy(DOE)through the PoSIES(Populus in the Southeast for Integrated Ecosystem Services,DE-EE0009280)USDA-NIFA McIntire Stennis grant(MISZ-067050).
文摘Understanding the phenology and productivity of Populus species is crucial for effective management and conservation strategies amid climate change.We investigated leaf budbreak timing,susceptibility to cold damage,leaf dynamics,and biomass production of 168 Populus genotypes with diverse provenances in the southeastern United States.Our study revealed significant variation in budbreak timing across different taxa and years,with genotypes inheriting traits adapted to their parents’local climates.Temperature emerged as a key factor triggering budbreak,while leaf development depended on other environmental cues such as photoperiod.Notably,budbreak occurred approximately 20 days earlier in 2023 compared to 2022 due to higher accumulated degree days(ADDs).Short-rotation-coppice(SRC)management delayed budbreak by five to ten days.Cold damage was significant in 2023,particularly for genotypes from northern provenances and those with P.maximowiczii parentage.Severe damage was also observed in eastern cottonwood(Populus deltoides×Populus deltoides(D×D))genotypes,despite most having southeastern US parentages.Leaf dynamics,including leaf duration and leaf area index(LAI),varied across taxa and sites,with earlier budbreak correlating with extended growing seasons and increased LAI.Biomass production was intricately linked to phenological events,with earlier budbreak leading to increased biomass production and greater susceptibility to cold damage.Our findings highlight the importance of genetics,environment,and coppicing management in understanding and managing Populus phenology and biomass production.These insights provide valuable guidance for developing effective breeding,conservation,and management strategies for Populus species in the context of climate change.
基金supported by grants from the USDA Forest Service,Western Wildlands Environmental Threat Assessment Center(20-JV-11221634-190)the US Geological Survey Southwest Climate Adaptation Science Center(G20AC00440-01)the U.S.National Science Foundation(NSF 2020185).
文摘Hydraulic vulnerability,the sensitivity of xylem embolism to water stress,is a major determinant trait associated with conifer mortality.This study investigated branch P50(50%hydraulic conductivity loss)of adult and juvenile ponderosa pines across multiple locations in the southwestern United States(SWUS),and examined relationships between P50 and climatic conditions,soil properties and forest management.Juvenile ponderosa pines had significantly more negative P50 values than adults on average.Both age groups exhibited a latitudinal pattern in P50 associated with regional climate conditions.Across the SWUS,juvenile P50 was positively correlated with growing season precipitation and temperature,and negatively correlated with soil pH and clay content.In some cases,significant differences in juvenile P50 between SWUS locations were associated with growing season moisture deficit,whereas other significant differences were less attributable to climate and may attest to potential genetic variation between populations.Climate variation,soil properties and population-level acclimation and/or adaptation may all influence the hydraulic vulnerability of juvenile ponderosa pines in the SWUS,promoting differences in stress tolerance of ponderosa pine forests across the region.
文摘The future distribution of invading species depends on the climate space available and certain life history traits that facilitate invasion.Here,to predict the spread potential of plant species introduced in North America north of Mexico(NAM),we compiled distribution and life history data(i.e.,seed size,life form,and photosynthetic pathways)for 3021 exotic plant species introduced to NAM.We comparatively examined the species’range size and climate space in both native and exotic regions and the role of key life history traits.We found that large climate space for most exotic plants is still available in NAM.The range sizes in global exotic regions could better predict the current range sizes in NAM than those in global native regions or global native plus exotic regions.C3 species had larger ranges on average than C4 and CAM plants,and herbaceous species consistently showed stronger relationships in range size between native and exotic regions than woody species,as was the case within the C3 species group.Seed size was negatively related to range size both in native regions and in NAM.However,seed size surprisingly showed a positive correlation with global exotic range size and no correlation with the current actual global(native plus exotic)range size.Our findings underline the importance of species’native distribution and life history traits in predicting the spread of exotic species.Future studies should continue to identify potential climate space and use underappreciated species traits to better predict species invasions under changing climate.
文摘Forest ecosystems can be characterized by a set of catenas arranged along the slope in mountainous areas as these affect microhabitat features,which in turn influence soil properties.Heretofore,few studies have examined how topographic variables affect soil properties and quality in semiarid regions.This study aimed to provide important insights into how catena position and shape influence soil properties,soil quality,and their interrelationships in a semiarid protected oak forest in western Iran.Basic soil properties were measured in the laboratory.In addition,the soil quality index(SQI)was calculated at different topographic positions along both convex(Λ-shaped)and concave(V-shaped)catenas at two soil depths(0-15 and 15-30 cm).The findings indicated that soil organic carbon and total nitrogen declined in the lower depth in both V-andΛ-shaped catenas and at all catena positions.The lowest porosity was observed in the lower depth at toeslope positions(TS)of both catenas.Substrate-induced respiration(SIR),microbial biomass carbon(MBC),and basal respiration(BR)were higher in the upper depths at TS positions on V-shaped catenas than onΛ-shaped catenas.These biological indices were consistently higher in the upper depths than in the lower depths across all positions of both catenas.SQI had the highest values at TS positions on both catenas and in the upper depths across all positions.Pearson correlations between soil properties indicated that SQI was most strongly and positively correlated with biological properties in both catenas.The nutrient levels,microbial activity,and soil porosity in both catena shapes and at both soil depths displayed a relatively downward trend with increasing elevation from toeslope to summit positions.The results showed that catena topographic sequence shape and position affected most of the soil properties,providing evidence of the important role of topography in creating pedodiversity in oak forest ecosystems.
基金supported by United States Department of Agriculture,Agricultural Research Service(No.58-8042-9-072)United States Department of Agriculture-National Institute of Food and Agriculture(No.2019-34263-30552)+1 种基金Management Information System(No.043050)United States Department of Agriculture-Agricultural Research Service-Non-Assistance Cooperative Agreement(No.58-6066-2-030).
文摘Background GOSSYM is a mechanistic,process-based cotton model that can simulate cotton crop growth and development,yield,and fiber quality.Its fiber quality module was developed based on controlled experiments explicitly conducted on the Texas Marker^(-1)(TM1)variety,potentially making its functional equations more aligned with this cultivar.To assess the model’s broader applicability,this study analyzed fiber quality data from 40 upland cotton cultivars,including TM1.The measured fiber quality from all cultivars was then compared with the modelsimulated fiber quality.Results Among the 40 upland cultivars,fiber strength varied from 28.4 cN·tex^(-1) to 34.6 cN·tex^(-1),fiber length ranged from 27.1 mm to 33.3 mm,micronaire value ranged from 2.7 to 4.6,and length uniformity index varied from 82.3%to 85.5%.The model simulated fiber quality closely matched the measured values for TM1,with the absolute percentage error(APE)being less than 0.92%for fiber strength,fiber length,and length uniformity index and 4.7%for micronaire.However,significant differences were observed for the other cultivars.The Pearson correlation coefficient(r)between the measured and simulated values was negative for all fiber quality traits,and Wilmotts’s index of agreement(WIA)was below 0.45,indicating a strong model bias toward TM1 without incorporating cultivar-specific parameters.After incorporating cultivar-specific parameters,the model’s performance improved significantly,with an average r-value of 0.84 and WIA of 0.88.Conclusions The adopted methodology and estimated cultivar-specific parameters improved the model’s simulation accuracy.This approach can be applied to newer cotton cultivars,enhancing the GOSSYM model’s utility and its applicability for agricultural management and policy decisions.
基金supported by the Key R&D Program of Shandong Province (2024LZGC007, 2024CXPT072, 2022LZGC001)Shandong Provincial Natural Science Foundation (ZR2024YQ069)+1 种基金the National Natural Science Foundation of China (32201863,32272181)the Taishan Scholars Program
文摘Wheat grains contain various bioactive substances,of which,condensed tannins(CT)are polymeric flavan-3-ols that accumulate in wheat seed coat influencing the end-use quality and nutritional value.However,the genetic architecture underlying CT biosynthesis in wheat grain remains unclear.Here,we studied the deposition and genetic regulation of CT in wheat grains,and found that CT deposited specifically in the testa layer of red-grained wheat as catechin-and epicatechin-formed polymers.Genome-wide association study identified 22 genetic loci affecting CT content,one of which,TaTAN,a single dominant gene controlling CT presence,was mapped to chromosome 3A in a segregation population.Further pan-genome analysis,transcriptome profiling and ethyl methanesulfonate induced mutants sequencing revealed a R2R3-MYB transcription factor,TaMYB10-3A,as the causal gene.Three loss-of-function alleles in TaMYB10-3A caused by large fragment inversion-deletion and insertion were identified which abolish both CT deposition and red pigmentation,demonstrating the pleiotropic effect of TaMYB10-3A on CT presence and grain color.TaMYB10-3A directly trans-activates core flavonoid genes such as chalcone synthase and dihydroflavonol 4-reductase to initiate CT biosynthesis.Our investigation provides a comprehensive understanding of CT presence in wheat grains and lays a solid foundation for manipulating CT metabolites to improve wheat grain end-use quality and nutrition values in wheat.
基金National Science Foundation supported this research through the Long Term Ecological Research(LTER)Grant to Hubbard Brook(NSF DEB1114804,1637685,and 2224545)by the project grant(NSF DEB,2020397).
文摘Foliar resorption is a principal nutrient conservation mechanism in terrestrial vegetation that could be sensitive to ongoing changes in climate and atmospheric nitrogen(N)deposition.We quantified N resorption in northern hardwood forests along an elevation gradient of decreasing temperature and increasing soil N availability to evaluate how this critical nutrient cycling process can be expected to respond to global and regional environmental changes.Foliar N resorption proficiency(NRP)increased significantly at lower elevations for both sugar maple and American beech,the dominant species in these forests.Foliar N resorption efficiency(NRE)also decreased with increasing elevation,but only in one year.Both species exhibited strong negative relationships between NRP and soil N availability.Thus,we anticipate that with climate warming and decreasing N inputs,northern hardwood forests can be expected to exhibit stronger N conservation via foliar resorption.Both species also exhibited strong correlations between resorption efficiency of N and C,but resorption of both elements was much greater for beech than sugar maple,suggesting contrasting mechanisms of nutrient conservation between these two widespread species.
基金The USDA NIFA McIntire Stennis project#1014653 and the University of Florida Institute of Food and Agricultural Sciences funded the research presented in this publication.
文摘A growing recognition that uneven-aged silviculture can offer multiple benefits to forested ecosystems has encouraged some landowners in the southern region of the United States to convert even-aged pine stands into multi-aged stands.For shade-intolerant pines of the southern United States,however,few studies have examined residual tree growth following silvicultural treatments that convert even-aged stands to multi-aged stands.Understanding the growth response of residual trees to different kinds of stand conversion treatments is critical to stand development and sustainability,as trees must be recruited into larger size classes during the conversion process to develop the desired stand structure and maintain productivity.In this study,we utilized a replicated,long-term silvicultural experimental trial in the southeastern United States to assess the effects of two cutting treatments(dispersed"single tree cutting"that created small canopy gaps and the"patch cutting"that created 0.1-0.8ha patch openings)and an uncut control on the 14-year growth(~cutting cycle length)of residual longleaf pine(Pinus palustris Mill.)trees.We found that tree growth,measured as mean basal area increment(BAI),was significantly higher following patch cutting(mean BAI of 16.97cm^(2))compared to both the single tree cutting(13.33cm^(2))and the uncut control(12.68cm^(2))(p<0.001).In patch cutting,the size of the patch opening,the location of trees surrounding the patch opening,and the position of the tree canopy all had a significant effect on BAI.Trees surrounding patch openings of 0.4ha exhibited greater growth,with a mean BAI of 19.24cm^(2),compared to those surrounding 0.1 and 0.8ha patch openings,which had mean BAI values of 15.89 and 15.71cm^(2),respectively(p<0.001).The position of a tree around the patch opening also influenced tree growth,as residual trees more to the North,South,and East sides exhibited significantly higher mean BAI than trees on the West side of the patch openings(p<0.001).However,distance from the patch opening border did not significantly affect the mean BAI(p=0.522).In all treatments,dominant and co-dominant trees exhibited higher BAI than intermediate and overtopped trees,indicating that tree canopy position significantly influenced tree growth(p<0.001).Understanding how residual trees grow after these silvicultural treatments is crucial for thoroughly assessing their efficacy with longleaf pine.This study's findings will enhance our understanding of stand dynamics during stand conversion and help land managers anticipate the growth of longleaf pine into larger size categories after single tree and patch cuttings.
文摘As interest in tropical forest restoration accelerates,understanding its hydrological implications is increasingly urgent.While concerns persist that reforestation will reduce annual water yields—particularly in drier climates—we highlight conditions under which forest landscape restoration(FLR)can improve seasonal water availability,especially during the dry season.We examine the trade-off between increased vegetation water use(“pumping”)and enhanced infiltration and subsurface retention(“sponging”)following forestation of degraded lands,the recovery of vegetation's ability to capture“occult”precipitation(fog)in specific coastal and montane settings,and the role of forest cover in enhancing moisture recycling and transport at multiple scales.A pan-tropical sensitivity analysis shows that in degraded landscapes with deep soils and pronounced rainfall seasonality,infiltration gains following forestation can offset or exceed evaporative losses,thereby supporting groundwater recharge and increasing dry-season flows in approximately 10%of cases,with an additional 8%showing near-neutral(slightly negative)outcomes.These findings challenge the assumption that forestation uniformly reduces water availability and underscore the need to prioritize dry-season flow recovery—rather than annual water yield—as a central hydrological goal of FLR.We call for trans-disciplinary research and long-term monitoring to inform forest restoration strategies,particularly in seasonally dry regions where water scarcity is most acute.
