Studies on long-term change of cropland is of great significance to the utilization of land resources and the implementation of scientific agricultural policies. The Korean Peninsula, adjacent to China, plays an impor...Studies on long-term change of cropland is of great significance to the utilization of land resources and the implementation of scientific agricultural policies. The Korean Peninsula, adjacent to China, plays an important role in the international environment of Northeast Asia. The Korean Peninsula includes South Korea and North Korea—two countries that have a great difference in their institutions and economic developments. Therefore, we aim to quantify the spatiotemporal changes of croplands in these two countries using Landsat Thematic Imager(TM) and Operational Land Imager(OLI) imagery, and to compare the differences of cropland changes between the two countries. This paper take full advantage of ODM approach(object-oriented segmentation and decision-tree classification based on multi-season imageries) to obtain the distribution of croplands in 1990 and 2015. Results showed that the overall classification accuracy of cropland data is 91.10% in 1990 and 92.52% in 2015. The croplands were mainly distributed in areas with slopes that were less than 8° and with elevations that were less than 300 m in the Korean Peninsula. However, in other region(slope > 8° or elevation > 300 m), the area and proportion of North Korea's croplands were significantly higher than that of South Korea. Croplands significantly increased by 15.02% in North Korea from 1990 to 2015. In contrast, croplands in South Korea slightly decreased by 1.32%. During the 25 years, policy shift, economic development, population growth, and urban sprawl played primary roles for cropland changes. Additionally, the regional differences of cropland changes were mainly due to different agriculture policies implemented by different countries. The achievements of this study can provide scientific guidance for the protection and sustainability of land resources.展开更多
The living morphology and infraciliature of two rare marine ciliates, Placussalinus Dietz, 1964 and Strombidium apolatum Wilbert and Song, 2005, collected from the coastalwaters near Qingdao, China, were investigated ...The living morphology and infraciliature of two rare marine ciliates, Placussalinus Dietz, 1964 and Strombidium apolatum Wilbert and Song, 2005, collected from the coastalwaters near Qingdao, China, were investigated by in vivo observation and protargol impregnationtechnique. The improved diagnosis for Placus salinus is as follows: medium-sized marine Placus, invivo (50-60) μm X (30-40) μm; cell elliptical to barrel-shaped; 28-31 somatic kineties; singlemacronucleus usually ellipsoid and one micronucleus located in the indention of the macronucleus;one contractile vacuole posteriorly positioned. Strombidium apolatum is characterized by: marinestrombidium (40-60) μm X (30-45) μm in vivo, cordiform in shape with somewhat pointed posteriorend and conspicuous apical protrusion; extrusomes prominent, about 15 μm in length and evenlyarranged along the circle kinety; about 16 collar and 5-6 buccal membranelles; one elongatemacronucleus and one micronucleus; circle and ventral kineties consisting of about 53 and 45dikinetids respectively.展开更多
Specimens belonging to the family Blenniidae were collected in a fishery resource investigation from the coastal waters of Xisha Islands and Hainan Island, South China Sea in 2016. Combining morphological results with...Specimens belonging to the family Blenniidae were collected in a fishery resource investigation from the coastal waters of Xisha Islands and Hainan Island, South China Sea in 2016. Combining morphological results with sequence analysis, we identified one specimen as Xiphasia matsubarai Okada & Suzuki, 1952. This represents a new record in the South China Sea. In morphology, the specimen has the following traits: body elongated, eel-like or ribbon-like in shape; flanks medium flat; the head small bluntly rounded anteriorly and without a moustache; eyes is slightly smaller, on upper lateral position of head, which is about equal to 1/5 of the length of the head; body without scales, lateral line has been degraded; both sides of the upper and lower jaws with a canine; gill is opening at the top of the pectoral fin base, approximately equal to the length of eye diameter. Dorsal fin Ⅺ, 96; pectoral fin 10; anal fin Ⅱ, 95. Head and body grey-brown, including 26 dark grey-brown bands; abdomen and lower operculum yellowish grey and colour lighter; and dorsal base long with dark grey. Origin of dorsal is located over the anterior margin of pupil; black blotch on dorsal fin between 8 th and 10 th dorsal spine; anal and caudal fins dark grey, pectoral and ventral fins pale yellow. Sequence analysis of cytochrome oxidase subunit I gene( COI) strongly supports the identity of the specimen as Ⅹ. matsubarai.展开更多
基金Under the auspices of Key Deployment Project of Chinese Academy of Sciences(No.KZZD-EW-08-02)
文摘Studies on long-term change of cropland is of great significance to the utilization of land resources and the implementation of scientific agricultural policies. The Korean Peninsula, adjacent to China, plays an important role in the international environment of Northeast Asia. The Korean Peninsula includes South Korea and North Korea—two countries that have a great difference in their institutions and economic developments. Therefore, we aim to quantify the spatiotemporal changes of croplands in these two countries using Landsat Thematic Imager(TM) and Operational Land Imager(OLI) imagery, and to compare the differences of cropland changes between the two countries. This paper take full advantage of ODM approach(object-oriented segmentation and decision-tree classification based on multi-season imageries) to obtain the distribution of croplands in 1990 and 2015. Results showed that the overall classification accuracy of cropland data is 91.10% in 1990 and 92.52% in 2015. The croplands were mainly distributed in areas with slopes that were less than 8° and with elevations that were less than 300 m in the Korean Peninsula. However, in other region(slope > 8° or elevation > 300 m), the area and proportion of North Korea's croplands were significantly higher than that of South Korea. Croplands significantly increased by 15.02% in North Korea from 1990 to 2015. In contrast, croplands in South Korea slightly decreased by 1.32%. During the 25 years, policy shift, economic development, population growth, and urban sprawl played primary roles for cropland changes. Additionally, the regional differences of cropland changes were mainly due to different agriculture policies implemented by different countries. The achievements of this study can provide scientific guidance for the protection and sustainability of land resources.
基金supported by‘The National Science Foundation of China’(Nos.40376045,30430090)
文摘The living morphology and infraciliature of two rare marine ciliates, Placussalinus Dietz, 1964 and Strombidium apolatum Wilbert and Song, 2005, collected from the coastalwaters near Qingdao, China, were investigated by in vivo observation and protargol impregnationtechnique. The improved diagnosis for Placus salinus is as follows: medium-sized marine Placus, invivo (50-60) μm X (30-40) μm; cell elliptical to barrel-shaped; 28-31 somatic kineties; singlemacronucleus usually ellipsoid and one micronucleus located in the indention of the macronucleus;one contractile vacuole posteriorly positioned. Strombidium apolatum is characterized by: marinestrombidium (40-60) μm X (30-45) μm in vivo, cordiform in shape with somewhat pointed posteriorend and conspicuous apical protrusion; extrusomes prominent, about 15 μm in length and evenlyarranged along the circle kinety; about 16 collar and 5-6 buccal membranelles; one elongatemacronucleus and one micronucleus; circle and ventral kineties consisting of about 53 and 45dikinetids respectively.
基金Supported by the National Natural Science Foundation of China(No.41376158)the Far Sea Fisheries Resources Monitoring and Assessment of South China Sea(No.2013050212)
文摘Specimens belonging to the family Blenniidae were collected in a fishery resource investigation from the coastal waters of Xisha Islands and Hainan Island, South China Sea in 2016. Combining morphological results with sequence analysis, we identified one specimen as Xiphasia matsubarai Okada & Suzuki, 1952. This represents a new record in the South China Sea. In morphology, the specimen has the following traits: body elongated, eel-like or ribbon-like in shape; flanks medium flat; the head small bluntly rounded anteriorly and without a moustache; eyes is slightly smaller, on upper lateral position of head, which is about equal to 1/5 of the length of the head; body without scales, lateral line has been degraded; both sides of the upper and lower jaws with a canine; gill is opening at the top of the pectoral fin base, approximately equal to the length of eye diameter. Dorsal fin Ⅺ, 96; pectoral fin 10; anal fin Ⅱ, 95. Head and body grey-brown, including 26 dark grey-brown bands; abdomen and lower operculum yellowish grey and colour lighter; and dorsal base long with dark grey. Origin of dorsal is located over the anterior margin of pupil; black blotch on dorsal fin between 8 th and 10 th dorsal spine; anal and caudal fins dark grey, pectoral and ventral fins pale yellow. Sequence analysis of cytochrome oxidase subunit I gene( COI) strongly supports the identity of the specimen as Ⅹ. matsubarai.
