RESUMO
Land use change has been one of the common problems in the context of urbanization in China. Social economy and land use interact with each other, and it is especially important for human society to adhere to sustainable development, and to deal with the contradictory relationship between the social-economic needs and land use change. The objectives of this study are: (1) Obtain time-series land-use classification data and its spatial distribution in Nanchang City; (2) Identify the characteristics and driving force of spatial-temporal land use changes in Nanchang City from 2000 to 2020; (3) Discuss the relationship between the urban expansion and social economy in Nanchang City. The results show that the spatial distribution of land use in Nanchang City has changed significantly from 2000 to 2020, and the largest area of land-use type in Nanchang City has been cropland. The cropland has continuously declined, and the urban area has increased significantly. A lot of cropland has been transformed into urban areas, and land use degree in Nanchang City has significantly increased. The spatial pattern of land use has greatly changed, and the city spatial pattern has become more aggregated, while the spatial distribution of cropland, forest and grassland has become more fragmented. Moreover, there has been an obvious correlation between social-economic development and the level of land use, and GDP has been the main driver of land use change. The central urban area of Nanchang city has been the main hotspot of land use change.
Assuntos
Florestas , Urbanização , Humanos , Cidades , China , Desenvolvimento Sustentável , Conservação dos Recursos NaturaisRESUMO
Urtica angustifolia Fisch. ex Hornem. is an important Chinese medicine. Here, the complete chloroplast genome of U. angustifolia was assembled and characterized. The length of the chloroplast genome was 146,679 bp with the typical quadripartite structure, containing two inverted repeats (IRs) of 24,595 bp separated by a large single-copy (LSC) region of 79,820 bp and a small single-copy (SSC) region of 17,669 bp. The whole chloroplast genome of U. angustifolia contains 111 genes, including 77 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Nucleotide variability analysis identified three hotspot regions (trnK-rps16, ndhF-rps32, and ycf1b) for genomic divergence and 52 simple sequence repeats. Phylogenetic analysis based on the complete chloroplast genomes exhibited that U. angustifolia formed a clade with Urtica lobatifolia and Hesperocnide tenella.
RESUMO
Chloroplast genome sequences have been used in phylogenetic and population genetics studies. Here, we assembled the chloroplast genome of Piper hancei Maxim. that is a traditional Chinese medicine. The genome length was 161,476 bp and included a pair of inverted repeats of 27,058 bp, a large single-copy region of 89,144 bp and a small single-copy region of 18,216 bp. It contained 113 different genes, including 79 protein-coding genes, 30 transfer RNA (tRNA), and four ribosomal RNA genes. Moreover, we also identified 82 SSRs. The phylogenetic inference based on the whole chloroplast genome of 20 taxa showed P. hancei was sister to P. kadsura.
RESUMO
In this study, we successfully assembled and analyzed the chloroplast genome of Engelhardtia fenzlii. The chloroplast genome of E. fenzlii was very similar to those of other Juglandaceae species. The E. fenzlii chloroplast genome is 161,713 bp in length and displays the typical quadripartite structure, which consists of a pair of IR regions (26,016 bp) separated by an LSC region (90,478 bp) and an SSC region (19,203 bp). The chloroplast genome of E. fenzlii contained a total of 112 unique genes, including 78 protein-coding genes, 30 tRNAs, and 4 rRNAs. Phylogenetic analysis based on the complete chloroplast genomes showed that Engelhardtia formed a monophyletic clade and E. fenzlii was sister to E. roxburghiana.