Wood density(WD)indicates important plant functions and plays a key role in carbon cycling of forest ecosystems by affecting wood decomposition.However,how WD varies globally and how it evolved through the evolutionar...Wood density(WD)indicates important plant functions and plays a key role in carbon cycling of forest ecosystems by affecting wood decomposition.However,how WD varies globally and how it evolved through the evolutionary history of angiosperms remain unclear.Here,by integrating data of WD,phylogeny and distributions for angiosperms worldwide,we estimated global spatiotemporal patterns of WD and their relationships with modern climate and paleoclimate.We found that mean WD decreased with latitude in the northern hemisphere but increased with latitude in the southern hemisphere.The interspecific WD variation within each geographic unit did not show clear latitudinal gradients.Temperature was the best predictor of the global geographic pattern in mean WD,while the geographic variation in mean WD across high-temperature regions could be explained by geographic variation in precipitation and precipitation seasonality(PS).Since the Cenozoic(66 million years ago(Mya)),WD increased first(until 20 Mya)and then decreased.In general,the Cenozoic WD was positively correlated with paleotemperature and negatively correlated with paleoprecipitation,especially during more arid periods.Interestingly,the evolutionary trends of WD on different continents differed,which corresponded to the divergence in WD patterns and their relationships with modern climate on different continents.Our results highlight the dominant effect of environmental temperature on global variation in angiosperm WD with an additional strong effect of PS.Our study also demonstrates the critical role of aridity and biogeographic idiosyncrasies in driving angiosperm WD evolution.展开更多
Introduction:The incidence of bacillary dysentery(BD)has declined significantly in China,yet BD outbreaks persist across multiple regions.This study describes the epidemiological characteristics of BD outbreaks nation...Introduction:The incidence of bacillary dysentery(BD)has declined significantly in China,yet BD outbreaks persist across multiple regions.This study describes the epidemiological characteristics of BD outbreaks nationwide and proposes targeted interventions for outbreak prevention and control.Methods:This study obtained BD outbreak data from the Public Health Emergency Event Surveillance System in China for descriptive epidemiological analysis and employed unconditional logistic regression to identify factors influencing outbreak magnitude.Results:During 2008–2024,China reported 176 BD outbreaks involving 9,854 cases and four deaths.The median attack rate and interquartile range for outbreaks were 5.99%(2.53%,13.32%).Annual outbreak reports decreased throughout the study period,with no outbreaks documented in 2023 and 2024.Among all outbreaks,75.6%occurred in rural areas,and 76.7%were reported in schools.Most outbreaks occurred during September or October(52.3%).Shigella sonnei and Shigella flexneri were the predominant outbreak pathogens;the principal transmission routes were waterborne(47.7%)and foodborne(23.9%).Median and interquartile ranges for response times and case counts were 3(2,6)days and 44(25,71)cases,respectively.Factors associated with larger outbreak size included S.sonnei as the causative pathogen,waterborne transmission,and outbreak duration of eight days or longer.Conclusions:In China,BD outbreak frequency has decreased substantially.September and October represent high-risk months,with schools serving as the primary outbreak setting during the back-to-school season.Strengthening BD prevention and control in educational institutions,with particular attention to water and food hygiene,remains essential for outbreak prevention.展开更多
The Convention on Biological Diversity seeks to conserve at least 30%of global land and water areas by 2030,which is a challenge but also an opportunity to better preserve biodiversity,including flowering plants(angio...The Convention on Biological Diversity seeks to conserve at least 30%of global land and water areas by 2030,which is a challenge but also an opportunity to better preserve biodiversity,including flowering plants(angiosperms).Herein,we compiled a large database on distributions of over 300,000 angiosperm species and the key functional traits of 67,024 species.Using this database,we constructed biodiversity-environment models to predict global patterns of taxonomic,phylogenetic,and functional diversity in terrestrial angiosperms and provide a comprehensive mapping of the three diversity facets.We further evaluated the current protection status of the biodiversity centers of these diversity facets.Our results showed that geographical patterns of the three facets of plant diversity exhibited substantial spatial mismatches and nonoverlapping conservation priorities.Idiosyncratic centers of functional diversity,particularly of herbaceous species,were primarily distributed in temperate regions and under weaker protection compared with other biodiversity centers of taxonomic and phylogenetic facets.Our global assessment of multifaceted biodiversity patterns and centers highlights the insufficiency and unbalanced conservation among the three diversity facets and the two growth forms(woody vs.herbaceous),thus providing directions for guiding the future conservation of global plant diversity.展开更多
Understanding large-scale patterns of biodiversity and their drivers remains central in ecology.Many hypotheses have been proposed,including hydrothermal dynamic hypothesis,tropical niche conservatism hypothesis,Janze...Understanding large-scale patterns of biodiversity and their drivers remains central in ecology.Many hypotheses have been proposed,including hydrothermal dynamic hypothesis,tropical niche conservatism hypothesis,Janzen’s hypothesis and a combination model containing energy,water,seasonality and habitat heterogeneity.Yet,their relative contributions to groups with different lifeforms and range sizes remain controversial,which have limited our ability to understand the general mechanisms underlying species richness patterns.Here we evaluated how lifeforms and species range sizes influenced the relative contributions of these three hypotheses to species richness patterns of a tropical family Moraceae.The distribution data of Moraceae species at a spatial resolution of 50 km×50 km and their lifeforms(i.e.shrubs,small trees and large trees)were compiled.The species richness patterns were estimated for the entire family,different life forms and species with different range sizes separately.The effects of environmental variables on species richness were analyzed,and relative contributions of different hypotheses were evaluated across life forms and species range size groups.The species richness patterns were consistent across different species groups and the species richness was the highest in Sichuan,Guangzhou and Hainan provinces,making these provinces the hotspots of this family.Climate seasonality is the primary factor in determining richness variation of Moraceae.The best combination model gave the largest explanatory power for Moraceae species richness across each group of range size and life forms followed by the hydrothermal dynamic hypothesis,Janzen’s hypothesis and tropical niche conservatism hypothesis.All these models has a large shared effects but a low independent effect(<5%),except rare species.These findings suggest unique patterns and mechanisms underlying rare species richness and provide a theoretical basis for protection of the Moraceae species in China.展开更多
基金supported by the National Natural Science Foundation of China(32125026,31988102)the National Key Research Development Program of China(2022YFF0802300).
文摘Wood density(WD)indicates important plant functions and plays a key role in carbon cycling of forest ecosystems by affecting wood decomposition.However,how WD varies globally and how it evolved through the evolutionary history of angiosperms remain unclear.Here,by integrating data of WD,phylogeny and distributions for angiosperms worldwide,we estimated global spatiotemporal patterns of WD and their relationships with modern climate and paleoclimate.We found that mean WD decreased with latitude in the northern hemisphere but increased with latitude in the southern hemisphere.The interspecific WD variation within each geographic unit did not show clear latitudinal gradients.Temperature was the best predictor of the global geographic pattern in mean WD,while the geographic variation in mean WD across high-temperature regions could be explained by geographic variation in precipitation and precipitation seasonality(PS).Since the Cenozoic(66 million years ago(Mya)),WD increased first(until 20 Mya)and then decreased.In general,the Cenozoic WD was positively correlated with paleotemperature and negatively correlated with paleoprecipitation,especially during more arid periods.Interestingly,the evolutionary trends of WD on different continents differed,which corresponded to the divergence in WD patterns and their relationships with modern climate on different continents.Our results highlight the dominant effect of environmental temperature on global variation in angiosperm WD with an additional strong effect of PS.Our study also demonstrates the critical role of aridity and biogeographic idiosyncrasies in driving angiosperm WD evolution.
文摘Introduction:The incidence of bacillary dysentery(BD)has declined significantly in China,yet BD outbreaks persist across multiple regions.This study describes the epidemiological characteristics of BD outbreaks nationwide and proposes targeted interventions for outbreak prevention and control.Methods:This study obtained BD outbreak data from the Public Health Emergency Event Surveillance System in China for descriptive epidemiological analysis and employed unconditional logistic regression to identify factors influencing outbreak magnitude.Results:During 2008–2024,China reported 176 BD outbreaks involving 9,854 cases and four deaths.The median attack rate and interquartile range for outbreaks were 5.99%(2.53%,13.32%).Annual outbreak reports decreased throughout the study period,with no outbreaks documented in 2023 and 2024.Among all outbreaks,75.6%occurred in rural areas,and 76.7%were reported in schools.Most outbreaks occurred during September or October(52.3%).Shigella sonnei and Shigella flexneri were the predominant outbreak pathogens;the principal transmission routes were waterborne(47.7%)and foodborne(23.9%).Median and interquartile ranges for response times and case counts were 3(2,6)days and 44(25,71)cases,respectively.Factors associated with larger outbreak size included S.sonnei as the causative pathogen,waterborne transmission,and outbreak duration of eight days or longer.Conclusions:In China,BD outbreak frequency has decreased substantially.September and October represent high-risk months,with schools serving as the primary outbreak setting during the back-to-school season.Strengthening BD prevention and control in educational institutions,with particular attention to water and food hygiene,remains essential for outbreak prevention.
基金supported by the National Natural Science Foundation of China(32125026,31988102)the National Key Research Development Program of China(2022YFF0802300)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31000000)。
文摘The Convention on Biological Diversity seeks to conserve at least 30%of global land and water areas by 2030,which is a challenge but also an opportunity to better preserve biodiversity,including flowering plants(angiosperms).Herein,we compiled a large database on distributions of over 300,000 angiosperm species and the key functional traits of 67,024 species.Using this database,we constructed biodiversity-environment models to predict global patterns of taxonomic,phylogenetic,and functional diversity in terrestrial angiosperms and provide a comprehensive mapping of the three diversity facets.We further evaluated the current protection status of the biodiversity centers of these diversity facets.Our results showed that geographical patterns of the three facets of plant diversity exhibited substantial spatial mismatches and nonoverlapping conservation priorities.Idiosyncratic centers of functional diversity,particularly of herbaceous species,were primarily distributed in temperate regions and under weaker protection compared with other biodiversity centers of taxonomic and phylogenetic facets.Our global assessment of multifaceted biodiversity patterns and centers highlights the insufficiency and unbalanced conservation among the three diversity facets and the two growth forms(woody vs.herbaceous),thus providing directions for guiding the future conservation of global plant diversity.
基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31000000)National Key Research Development Program of China(2017YFA0605101,2017YFC0505203)National Natural Science Foundation of China(32C125026,31988102,31770566).
文摘Understanding large-scale patterns of biodiversity and their drivers remains central in ecology.Many hypotheses have been proposed,including hydrothermal dynamic hypothesis,tropical niche conservatism hypothesis,Janzen’s hypothesis and a combination model containing energy,water,seasonality and habitat heterogeneity.Yet,their relative contributions to groups with different lifeforms and range sizes remain controversial,which have limited our ability to understand the general mechanisms underlying species richness patterns.Here we evaluated how lifeforms and species range sizes influenced the relative contributions of these three hypotheses to species richness patterns of a tropical family Moraceae.The distribution data of Moraceae species at a spatial resolution of 50 km×50 km and their lifeforms(i.e.shrubs,small trees and large trees)were compiled.The species richness patterns were estimated for the entire family,different life forms and species with different range sizes separately.The effects of environmental variables on species richness were analyzed,and relative contributions of different hypotheses were evaluated across life forms and species range size groups.The species richness patterns were consistent across different species groups and the species richness was the highest in Sichuan,Guangzhou and Hainan provinces,making these provinces the hotspots of this family.Climate seasonality is the primary factor in determining richness variation of Moraceae.The best combination model gave the largest explanatory power for Moraceae species richness across each group of range size and life forms followed by the hydrothermal dynamic hypothesis,Janzen’s hypothesis and tropical niche conservatism hypothesis.All these models has a large shared effects but a low independent effect(<5%),except rare species.These findings suggest unique patterns and mechanisms underlying rare species richness and provide a theoretical basis for protection of the Moraceae species in China.
