Today,resource depletion threatens a number of resource-based cities in China.The ecological security problem caused by the long-term exploitation of natural resources is a key issue to be solved in the development of...Today,resource depletion threatens a number of resource-based cities in China.The ecological security problem caused by the long-term exploitation of natural resources is a key issue to be solved in the development of resource-exhausted cities.Using 23 indicators,this study evaluated the ecological security status and development trends of 21 resource-exhausted cities in China from 2011 to 2017.The results showed that from 2011 to 2015,the overall ecological security of this type of city was low,with over 60%of the cities at an unsafe level.However,ecological security improved rapidly after 2016,and by 2017,all of the cities had reached the critical safety level.The top 10 indicators of ecological security included industrial sulfur dioxide emissions,water supply,agricultural fertilizer application,and forest coverage.These 10 indicators’cumulative contribution to ecological security was 48.3%;among them,reducing industrial sulfur dioxide emissions contributed the most at 5.7%.These findings can help governments better understand the ecological security status of resource-exhausted cities,and it can provide a reference for the allocation of funds and other resources to improve the ecological safety of these cities.展开更多
Broussonetia kazinoki×Broussonetia papyrifera(ZJGS)is a hybrid species in Moraceae family,which has a very complicated hybrid origin.The excellent characteristics of fast growth,strong soil and water conservation...Broussonetia kazinoki×Broussonetia papyrifera(ZJGS)is a hybrid species in Moraceae family,which has a very complicated hybrid origin.The excellent characteristics of fast growth,strong soil and water conservation ability,high leaf protein content and stem fiber content in ZJGS make it both ecological benefits in the mining area and economically valuable.This study aims to further understand ZJGS and other Moraceae taxa through the ZJGS chloroplast(cp)genome structure and the comparison with 12 closely related Moraceae species.Among the 13 Moraceae species,the cp genome length of seven Broussonetia species(ranges from 160,239 bp to 162,594 bp)is larger than that of six Morus species(ranges from 158,459 bp to 159,265 bp).Among the 77 shared protein-coding genes(PCGs)in Moraceae species,the obvious positive selection of Ka/Ks ratios acted on petD and rpl16 genes of B.kazinoki and B.papyrifera,respectively.Phylogenetic analysis based on shared PCGs from 28 species shows that ZJGS is closely related to maternal B.kazinoki.These findings provide data support for the origin of ZJGS hybridization and provide genomic resources for future ZJGS resource development and molecular breeding.展开更多
Darwin’s finches are the most classic case of evolution.Early studies on the evolution of this species were mainly based on morphology.Until now,the mitochondrial genome of Geospiza magnirostris has been sequenced an...Darwin’s finches are the most classic case of evolution.Early studies on the evolution of this species were mainly based on morphology.Until now,the mitochondrial genome of Geospiza magnirostris has been sequenced and the study explored the characteristics of the complete genome of G.magnirostris and verified the evolutionary position of it.The 13 PCGs initiated by ATN codons.The stop codons of three PCGs(ND2,COX3 and ND4)were incomplete,with only T-or TA-replacing complete form TAA or TAG.All the tRNA genes expressed a typical cloverleaf secondary structure,except for tRNA^(Ser1)(AGY),whose dihydrouridine(DHU)arm was lack and instead with a simple loop.In the sequence of the control region of G.magnirostris,we found six simple repeat tandem sequences with a total length of 42 bp.Two characteristic conserved overlapping junction(ATGCTAA)and(CAAGAAAG)were observed as reported for eight selected Passeriformes birds.A special conserved overlapping junction(ATCTTACC)involved in mitochondrial transcription termination was found between tRNA^(Tyr) and COX1 in G.magnirostris’s control region.Four most frequently used amino acids in G.magnirostris’s PCGs were Leu1(CUN),Ile,Thr,Ala.The codon usage of G.magnirostris was relatively average,and there was no particular bias.The ratio Ka/Ks results showed that G.magnirostris receives less natural selection pressure.The phylogenetic relationships and cluster analysis of relative codon usage showed that G.magnirostris and Thraupis episcopus clustered in one branch.The phylogenetic position of G.magnirostris was consistent with the traditional taxonomic of Thraupis.The results supported the conclusion that G.magnirostris belongs to the morphological classification of the family Thraupidae.展开更多
Rodent pests severely damage agricultural crops.Outbreak risk models of rodent pests often do not include sufficient information regarding geographic variation.Habitat plays an important role in rodent-pest outbreak r...Rodent pests severely damage agricultural crops.Outbreak risk models of rodent pests often do not include sufficient information regarding geographic variation.Habitat plays an important role in rodent-pest outbreak risk,and more information about the relationship between habitat and crop protection is urgently needed.The goal of the present study was to provide an outbreak risk map for the Dongting Lake region and to understand the relationship between rodent-pest outbreak variation and habitat distribution.The main rodent pests in the Dongting Lake region are Yangtze voles(Microtus fortis).These pests cause massive damage in outbreak years,most notably in 2007.Habitat evaluation and ecological details were obtained by analyzing the correlation between habitat suitability and outbreak risk,as indicated by population density and historical events.For the source-sink population,96.18%of Yangtze vole disaster regions were covered by a 10-km buffer zone of suitable habitat in 2007.Historical outbreak frequency and peak population density were significantly correlated with the proportion of land covered by suitable habitat(r=0.68,P=0.04 and r=0.76,P=0.03,respectively).The Yangtze vole population tends to migrate approximately 10 km in outbreak years.Here,we propose a practical method for habitat evaluation that can be used to create integrated pest management plans for rodent pests when combined with basic information on the biology,ecology and behavior of the target species.展开更多
基金This work was supported by the Technology R&D Program of Changsha City(nos.kc1702045 and kq1901145)the Key Technology R&D Program of Hunan Province(nos.2016TP2007,2017TP2006,and 2016TP1014).
文摘Today,resource depletion threatens a number of resource-based cities in China.The ecological security problem caused by the long-term exploitation of natural resources is a key issue to be solved in the development of resource-exhausted cities.Using 23 indicators,this study evaluated the ecological security status and development trends of 21 resource-exhausted cities in China from 2011 to 2017.The results showed that from 2011 to 2015,the overall ecological security of this type of city was low,with over 60%of the cities at an unsafe level.However,ecological security improved rapidly after 2016,and by 2017,all of the cities had reached the critical safety level.The top 10 indicators of ecological security included industrial sulfur dioxide emissions,water supply,agricultural fertilizer application,and forest coverage.These 10 indicators’cumulative contribution to ecological security was 48.3%;among them,reducing industrial sulfur dioxide emissions contributed the most at 5.7%.These findings can help governments better understand the ecological security status of resource-exhausted cities,and it can provide a reference for the allocation of funds and other resources to improve the ecological safety of these cities.
基金supported by Hunan Provincial Natural Science Foundation of China[Grant No.2019JJ50027]China Postdoctoral Science Foundation[Grant No.2020M683592]+1 种基金Key Projects of National Forestry and Grassland Bureau[Grant No.201801]Scientific Innovation Fund for Post-graduates of Central South University of Forestry and Technology[Grant No.CX20191004].
文摘Broussonetia kazinoki×Broussonetia papyrifera(ZJGS)is a hybrid species in Moraceae family,which has a very complicated hybrid origin.The excellent characteristics of fast growth,strong soil and water conservation ability,high leaf protein content and stem fiber content in ZJGS make it both ecological benefits in the mining area and economically valuable.This study aims to further understand ZJGS and other Moraceae taxa through the ZJGS chloroplast(cp)genome structure and the comparison with 12 closely related Moraceae species.Among the 13 Moraceae species,the cp genome length of seven Broussonetia species(ranges from 160,239 bp to 162,594 bp)is larger than that of six Morus species(ranges from 158,459 bp to 159,265 bp).Among the 77 shared protein-coding genes(PCGs)in Moraceae species,the obvious positive selection of Ka/Ks ratios acted on petD and rpl16 genes of B.kazinoki and B.papyrifera,respectively.Phylogenetic analysis based on shared PCGs from 28 species shows that ZJGS is closely related to maternal B.kazinoki.These findings provide data support for the origin of ZJGS hybridization and provide genomic resources for future ZJGS resource development and molecular breeding.
基金The study was supported by National Natural Science Foundation of China[Grant No.U20A20118]College Students’Innovative Entrepreneurial Training Plan Program of Shannxi Province[Grant No.S202010712295].
文摘Darwin’s finches are the most classic case of evolution.Early studies on the evolution of this species were mainly based on morphology.Until now,the mitochondrial genome of Geospiza magnirostris has been sequenced and the study explored the characteristics of the complete genome of G.magnirostris and verified the evolutionary position of it.The 13 PCGs initiated by ATN codons.The stop codons of three PCGs(ND2,COX3 and ND4)were incomplete,with only T-or TA-replacing complete form TAA or TAG.All the tRNA genes expressed a typical cloverleaf secondary structure,except for tRNA^(Ser1)(AGY),whose dihydrouridine(DHU)arm was lack and instead with a simple loop.In the sequence of the control region of G.magnirostris,we found six simple repeat tandem sequences with a total length of 42 bp.Two characteristic conserved overlapping junction(ATGCTAA)and(CAAGAAAG)were observed as reported for eight selected Passeriformes birds.A special conserved overlapping junction(ATCTTACC)involved in mitochondrial transcription termination was found between tRNA^(Tyr) and COX1 in G.magnirostris’s control region.Four most frequently used amino acids in G.magnirostris’s PCGs were Leu1(CUN),Ile,Thr,Ala.The codon usage of G.magnirostris was relatively average,and there was no particular bias.The ratio Ka/Ks results showed that G.magnirostris receives less natural selection pressure.The phylogenetic relationships and cluster analysis of relative codon usage showed that G.magnirostris and Thraupis episcopus clustered in one branch.The phylogenetic position of G.magnirostris was consistent with the traditional taxonomic of Thraupis.The results supported the conclusion that G.magnirostris belongs to the morphological classification of the family Thraupidae.
基金The authors thank Yalan Liu and Yuhuan Ren for providing 2007 Yangtze vole disaster region data.The research was supported by the Knowledge Innovation Program of The Chinese Academy Sciences(KSCXEW-N-05)the Exclusive Research Fund for the Public Good Granted by Ministry of Environment Protection of PRC(2010467022).
文摘Rodent pests severely damage agricultural crops.Outbreak risk models of rodent pests often do not include sufficient information regarding geographic variation.Habitat plays an important role in rodent-pest outbreak risk,and more information about the relationship between habitat and crop protection is urgently needed.The goal of the present study was to provide an outbreak risk map for the Dongting Lake region and to understand the relationship between rodent-pest outbreak variation and habitat distribution.The main rodent pests in the Dongting Lake region are Yangtze voles(Microtus fortis).These pests cause massive damage in outbreak years,most notably in 2007.Habitat evaluation and ecological details were obtained by analyzing the correlation between habitat suitability and outbreak risk,as indicated by population density and historical events.For the source-sink population,96.18%of Yangtze vole disaster regions were covered by a 10-km buffer zone of suitable habitat in 2007.Historical outbreak frequency and peak population density were significantly correlated with the proportion of land covered by suitable habitat(r=0.68,P=0.04 and r=0.76,P=0.03,respectively).The Yangtze vole population tends to migrate approximately 10 km in outbreak years.Here,we propose a practical method for habitat evaluation that can be used to create integrated pest management plans for rodent pests when combined with basic information on the biology,ecology and behavior of the target species.
