Soil cracking is an important process influencing water and solutes transport in the Yuanmou Dry-hot Valley region of Southwest China. Studying the morphological development of soil cracks helps to further reveal the ...Soil cracking is an important process influencing water and solutes transport in the Yuanmou Dry-hot Valley region of Southwest China. Studying the morphological development of soil cracks helps to further reveal the close relationship between the soil cracking process and water movement in such semi-arid regions. Here we report regular changes on surface morphology of soil cracks with decreasing water in four different soils (Typ-Ustic Ferrisols,Ver-Ustic Ferrisols,Tru-Ustic Vertisols and Typ-Ustic Vertisols) through simulation experiments. Our results indicate the following: 1) Different soils ultimately have different development degrees of soil cracks,according to their various values of crack area density. Soil cracks in Typ-Ustic Ferrisols can only develop to the feeble degree,while those in the other three soils are capable of developing into the intensive degree,and even into the extremely intensive degree. 2) Soil crack complexity,as expressed by the value of the area-weighted mean of crack fractal dimension (AWMFRAC),is found to continuously decrease as a whole through the whole cracking process in all the studied soils. 3) Soil crack connectivity shows a uniform trend in the studied soils,that is to say,connectivity gradually increases with soil crack development.展开更多
Agricultural practices are the main stay of the people of Uttranchal. Out of the total population, more than 75% people are engaged either with the main occupation of agriculture or its allied practices, dominated by ...Agricultural practices are the main stay of the people of Uttranchal. Out of the total population, more than 75% people are engaged either with the main occupation of agriculture or its allied practices, dominated by traditional subsistence cereal farming. Among them, the main crops are rice, wheat, millet, barley, all types of pulses, all types of oilseeds and almost all types of fruits. The crops, vegetables and fruits of all varieties are grown in the different climatic zones such as tropical, temperate, and cold because, the region is characterized by the different altitudinal zones elevated from 200 m to more than 8000m. As a result, different climates are found from hot tropical to sub temperate and chilly cold. Pulses varieties are grown extensively. Among vegetables, potato, onion, carrot, all types of green leaf vegetables, brinzal, pumpkin, ladyfinger, pea, gram, radish, ginger, garlic, etc, are grown widely. All fruit varieties are grown in the different altitudinal zones. The main fruits are orange, malta (a big size of orange), elephant citrus, lemon and all other types of citrus, apple, stone fruits including peach and pears, many kinds of nuts, and the fruits which are grown in the low lying areas. In spite of feasible climatic conditions, agricultural dominant society, and availability of all types of crops, the production and productivity of these crops are very low, even they are unable to meet the grain-need of the people in Uttaranchal. Agricultural crops are grown almost in all the altitudinal zones — from the low-lying areas, which are called ‘Gangarh’, to the highly elevated region, where the legendary term is given as ‘Danda’. The growing seasons vary according to the heights. The present paper aims to discuss the agricultural practices including cropping season, cropping pattern, land use, production of crops and ecological aspect of agricultural system in this Himalayan state and suggest some measures for developing farming system, which could lead the sustainability, in terms 展开更多
A novel species of Rhamnaceae,Colubrina zhaoguangii,is discovered in Sichuan,China,during the biodiversity investigations of the Second Tibetan Plateau Scientific Expedition and Research.Detailed descriptions and illu...A novel species of Rhamnaceae,Colubrina zhaoguangii,is discovered in Sichuan,China,during the biodiversity investigations of the Second Tibetan Plateau Scientific Expedition and Research.Detailed descriptions and illustrations of the new species are presented herein.To date,the new species is only found in dry-warm river valleys of the Jinsha River basin in the Hengduan Mountains region(HDM).Compared with the other two known Chinese Colubrina species,C.zhaoguangii features by the habit of twisted shrub and tiny leaves with emarginate apex.In morphology,the new species highly resembles C.alluaudii endemic in Madagascar and C.viridis in northwestern Mexico,whereas it is distinguished from these two relatives by its minutely white scales on the leaf blades.The discovery of C.zhaoguangii reminds us again that the bottom region is also important for biodiversity conservation in HDM and should be a flora survey priority.展开更多
A female Brown-fronted Woodpecker (Dendrocopos auriceps) was first observed and photographed in the Jilong Valley of the Mount Qomolangma Region,China,on 21 May 2012.The coordinates of the site are 28°19′25.03″...A female Brown-fronted Woodpecker (Dendrocopos auriceps) was first observed and photographed in the Jilong Valley of the Mount Qomolangma Region,China,on 21 May 2012.The coordinates of the site are 28°19′25.03″N,85°20′29.70"E at an elevation of 2150 m.A few months later,a male was observed at 28°20′02.49"N,85°20′46.30"E on 8 August at an elevation of 2197 m.The habitat is a mountain temperate coniferous and dry broadleaved mixed forest of the warm temperate zone.展开更多
基金Under the auspices of National Natural Science Foundation of China (No. 40901009)National Key Technologies Research and Development Program in the Eleventh Five-Year Plan of China (No. 2008BAD98B02, 2006BAC01A11)+1 种基金the Western Light Program of Talents Cultivating of Chinese Academy of Sciences (2008)the Foundation of Key Laboratory of Mountain Hazards and Surface Process, Chinese Academy of Sciences
文摘Soil cracking is an important process influencing water and solutes transport in the Yuanmou Dry-hot Valley region of Southwest China. Studying the morphological development of soil cracks helps to further reveal the close relationship between the soil cracking process and water movement in such semi-arid regions. Here we report regular changes on surface morphology of soil cracks with decreasing water in four different soils (Typ-Ustic Ferrisols,Ver-Ustic Ferrisols,Tru-Ustic Vertisols and Typ-Ustic Vertisols) through simulation experiments. Our results indicate the following: 1) Different soils ultimately have different development degrees of soil cracks,according to their various values of crack area density. Soil cracks in Typ-Ustic Ferrisols can only develop to the feeble degree,while those in the other three soils are capable of developing into the intensive degree,and even into the extremely intensive degree. 2) Soil crack complexity,as expressed by the value of the area-weighted mean of crack fractal dimension (AWMFRAC),is found to continuously decrease as a whole through the whole cracking process in all the studied soils. 3) Soil crack connectivity shows a uniform trend in the studied soils,that is to say,connectivity gradually increases with soil crack development.
文摘Agricultural practices are the main stay of the people of Uttranchal. Out of the total population, more than 75% people are engaged either with the main occupation of agriculture or its allied practices, dominated by traditional subsistence cereal farming. Among them, the main crops are rice, wheat, millet, barley, all types of pulses, all types of oilseeds and almost all types of fruits. The crops, vegetables and fruits of all varieties are grown in the different climatic zones such as tropical, temperate, and cold because, the region is characterized by the different altitudinal zones elevated from 200 m to more than 8000m. As a result, different climates are found from hot tropical to sub temperate and chilly cold. Pulses varieties are grown extensively. Among vegetables, potato, onion, carrot, all types of green leaf vegetables, brinzal, pumpkin, ladyfinger, pea, gram, radish, ginger, garlic, etc, are grown widely. All fruit varieties are grown in the different altitudinal zones. The main fruits are orange, malta (a big size of orange), elephant citrus, lemon and all other types of citrus, apple, stone fruits including peach and pears, many kinds of nuts, and the fruits which are grown in the low lying areas. In spite of feasible climatic conditions, agricultural dominant society, and availability of all types of crops, the production and productivity of these crops are very low, even they are unable to meet the grain-need of the people in Uttaranchal. Agricultural crops are grown almost in all the altitudinal zones — from the low-lying areas, which are called ‘Gangarh’, to the highly elevated region, where the legendary term is given as ‘Danda’. The growing seasons vary according to the heights. The present paper aims to discuss the agricultural practices including cropping season, cropping pattern, land use, production of crops and ecological aspect of agricultural system in this Himalayan state and suggest some measures for developing farming system, which could lead the sustainability, in terms
基金This study was supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0301)National Natural Science Foundation of China(31860167 and 32101234)Wild Plants Sharing and Service Platform of Sichuan Province.
文摘A novel species of Rhamnaceae,Colubrina zhaoguangii,is discovered in Sichuan,China,during the biodiversity investigations of the Second Tibetan Plateau Scientific Expedition and Research.Detailed descriptions and illustrations of the new species are presented herein.To date,the new species is only found in dry-warm river valleys of the Jinsha River basin in the Hengduan Mountains region(HDM).Compared with the other two known Chinese Colubrina species,C.zhaoguangii features by the habit of twisted shrub and tiny leaves with emarginate apex.In morphology,the new species highly resembles C.alluaudii endemic in Madagascar and C.viridis in northwestern Mexico,whereas it is distinguished from these two relatives by its minutely white scales on the leaf blades.The discovery of C.zhaoguangii reminds us again that the bottom region is also important for biodiversity conservation in HDM and should be a flora survey priority.
文摘A female Brown-fronted Woodpecker (Dendrocopos auriceps) was first observed and photographed in the Jilong Valley of the Mount Qomolangma Region,China,on 21 May 2012.The coordinates of the site are 28°19′25.03″N,85°20′29.70"E at an elevation of 2150 m.A few months later,a male was observed at 28°20′02.49"N,85°20′46.30"E on 8 August at an elevation of 2197 m.The habitat is a mountain temperate coniferous and dry broadleaved mixed forest of the warm temperate zone.
