The Annapurna Conservation Area (ACA), the first conservation area and the largest protected area (PA) in Nepal, is incredibly rich in biodiversity. Notwithstanding this, orchids in the ACA have not been explored enou...The Annapurna Conservation Area (ACA), the first conservation area and the largest protected area (PA) in Nepal, is incredibly rich in biodiversity. Notwithstanding this, orchids in the ACA have not been explored enough yet thus making the need for ambitious research to be carried out. Previous study only included 81 species of orchids within ACA. This study aims to update the record of species and genera richness in the ACA. In total 198 species of orchids, belonging to 67 genera (40% and 62% of the total recorded orchid species and genera in Nepal) has been recorded in ACA. This represents an increase of 144% in species and 56% in genera over the previous data. Out of the 198 species, 99 were epiphytes, 6 were holomycotrophic and 93 were terrestrial. Among the 67 genera, Bulbophyllum (17) species were dominant, followed by Dendrobium (16), Herminium (10), Coelogyne, Plantanthera (9 each), Eria, Habenaria, Oberonia (8 each), Calanthe (7), and Liparis (6). Fifty-six species were found to be ornamentally significant and 85 species medicinally significant.展开更多
Land use conflicts(LUCs),as a spatial manifestation of the conflicts in the human-land relationships,have a profound impact on regional sustainable development.For China’s metropolitan junction areas(MJAs),the existe...Land use conflicts(LUCs),as a spatial manifestation of the conflicts in the human-land relationships,have a profound impact on regional sustainable development.For China’s metropolitan junction areas(MJAs),the existence of“administrative district economies”has made the issue of LUCs more prominent.Based on a case study of the central Chengdu–Chongqing region,we conducted an exploratory spatial data analysis of the evolutionary process of regional LUCs.Furthermore,structural equation modeling was utilized to analyze the dynamic mechanism of LUCs in MJAs,with a particular emphasis on exploring the influences of administrative boundary.The results showed that from 2010 to 2020,LUCs in the central Chengdu–Chongqing region continued to worsen,and the spatial process conflict and spatial structure conflict indices increased by more than 30.0%.The intensification of LUCs in the central Chengdu–Chongqing region from 2010 to 2020 was mainly the result of the deterioration of conflicts in evaluation units with low conflict levels.LUCs in China’s metropolitan areas generally presented a circular gradient distribution,weakening from the core to the periphery,but there were some strong isolated conflict zones in the outer regions.LUCs in China’s MJAs were the result of interactions among multiple factors,e.g.,natural environment,socio-economic development,policy and institutional processes,and administrative boundary effects.Administrative boundary affected the flow of socio-economic elements,changing the supply-and-demand competition of stakeholders for land resources,consequently exerting an indirect influence on LUCs.This study advances the theory of the dynamic mechanism of LUCs,and provides theoretical support for the governance of these conflicts in transboundary areas.展开更多
This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the s...This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the study, namely Mangoum, Makeka and Fossang, representative of the three dominant soil types of the noun plain (Andosols, Acrisols and Ferralsols). Three land uses were selected per site including natural vegetation, agroforest and crop field. Soil was sampled at three depths;0 - 20 cm, 20 - 40 cm, and 40 - 60 cm. Analysis of variance showed that soil type did not significantly influence carbon storage, but rather land uses and soil depth. SOCS decreased significantly with depth in all the sites, with an average stock of 66.3 ± 15.8 tC/ha at 0 - 20 cm, compared to an average stock of 33.3 ± 7.4 tC/ha at 40 - 60 cm. SOCS was significantly highest in the natural formation with 57.2 ± 19.7 tC/ha, and lowest in cultivated fields, at 37.7 ± 10.6 tC/ha. Andosols, with their high content of coarse fragments, stored less organic carbon than Ferralsols and Acrisols.展开更多
The vertical variation and storage of nitrogen in the depth of 0-150 cm of an aquic brown soil were studied under 14 years of four land use patterns, i.e., paddy field, maize field, fallow field and woodland in Shenya...The vertical variation and storage of nitrogen in the depth of 0-150 cm of an aquic brown soil were studied under 14 years of four land use patterns, i.e., paddy field, maize field, fallow field and woodland in Shenyang Experimental Station of Ecology, Chinese Academy of Sciences in November of 2003. The results showed that different land uses had different profile distributions of soil total nitrogen (STN), alkali N, ammonium (NH4+-N) and nitrate (NO3--N). The sequence of STN storage was woodland >maize field > fallow field > paddy field, while that of NO3--N content was maize field > paddy field > woodland > fallow field, suggesting the different root biomass and biological N cycling under various land uses. The STN storage in the depth of 0-100 cm of woodland averaged to 11.41 thm-1, being 1.65 and 1.25 times as much as that in paddy and maize fields, respec-tively, while there was no significant difference between maize and fallow fields. The comparatively higher amount of NO3--N in maize and paddy fields may be due to nitrogen fertilization and anthropogenic disturbance. Soil alkali N was significantly related with STN, and the correlation could be expressed by a linear regression model under each land use (R20.929, p<0.001). Such a correlation was slightly closer in nature (woodland and fallow field) than in agro ecosystems (paddy and maize fields). Heavy N fertilization induced an excess of crop need, and led to a comparatively higher amount of soil NO3--N in cultivated fields than in fallow field and woodland. It is suggested that agroforestry practices have the potential to make a significant contribution to both crop production and environment protection.展开更多
The robust principal component analysis (RPCA) is a technique of multivariate statistics to assess the social and economic environment quality. This paper aims to explore a RPCA algorithm to analyze the spatial hete...The robust principal component analysis (RPCA) is a technique of multivariate statistics to assess the social and economic environment quality. This paper aims to explore a RPCA algorithm to analyze the spatial heterogeneity of social and economic environment of land uses (SEELU). RPCA supplies one of the most efficient methods to derive the most important components or factors affecting the regional difference of the social and economic environment. According to the spatial distributions of the levels of SEELU,the total land resources of China were divided into eight zones numbered by Ⅰ to Ⅷ which spatially referred to the eight levels of SEELU.展开更多
The chemical constituents, pharmacological activity and traditional uses of 20 species attributed to the genus Elsholtzia (Labiatae) used in China are reviewed and compared. A survey of the literature available show...The chemical constituents, pharmacological activity and traditional uses of 20 species attributed to the genus Elsholtzia (Labiatae) used in China are reviewed and compared. A survey of the literature available shows that these species are used mostly for the treatment of respiratory and gastrointestinal disorders. Additionally, some of these Elsholtzia species show antibacterial, anti-inflammatory, relieving fever, analgesic activities and myocardial ischemia protection. Generally, the essential oils or flavonoids from these plant extracts are assumed to be the active principles.展开更多
Clinacanthus nutans Lindau is known as snake grass belonging to the Acanlhaceae family.This plant has diverse and potential medicinal uses in traditional herbal medicine for treating skin rashes,insects and snake bite...Clinacanthus nutans Lindau is known as snake grass belonging to the Acanlhaceae family.This plant has diverse and potential medicinal uses in traditional herbal medicine for treating skin rashes,insects and snake bites,lesions caused by herpes simplex virus,diabetes,and gout in Malaysia.Indonesia.Thailand and China.Phylochemieal investigations documented the varied contents of bioaclive compounds from litis plant namely flavonoids,glycosides,glycoglyeerolipids.cerebrosides and monoacylmonogalatosylglycerol.The pharmacological experiment proved that various types of extracts and pure compounds from this species exhibited a broad range of biological properties such as anti-inflammatory,antiviral,antioxidant,and anti-diabetic activities.The lindings of toxicity study showed that extracts from this plant did not show any toxicity thus it can be used as strong therapeutic agents for specific diseased conditions.However,further experiments on chemical components and their mode of action showing biological activities are required to elucidate the complete phytochemical profile and assess to confirm their suitability tor future drugs.This review summarizes the medicinal uses,phytochemistry and pharmacology of this plant in order to explore its therapeutic potential and gaps necessitating for prospected research work.展开更多
Syzygium cumini(S.cumini)(L.) Skeels(jambolan) is one of the widely used medicinal plants in the treatment of various diseases in particular diabetes.The present review has been primed to describe the existing data on...Syzygium cumini(S.cumini)(L.) Skeels(jambolan) is one of the widely used medicinal plants in the treatment of various diseases in particular diabetes.The present review has been primed to describe the existing data on the information on botany,phytochemical constituents,traditional uses and pharmacological actions of 5.cumini(L.) Skeels(jambolan).Electronic database search was conducted with the search terms of Eugenia jambolana,S.cumini,jambolan,common plum and java plum.The plant has been viewed as an antidiabetic plant since it became commercially available several decades ago.During last four decades,numerous folk medicine and scientific reports on the antidiabetic effects of this plant have been cited in the literature.The plant is rich in compounds containing anthocyanins,glucoside,ellagic acid,isoquercetin,kaemferol and myrecetin.The seeds are claimed to contain alkaloid,jambosine,and glycoside jambolin or antimellin,which halts the diastalic conversion of starch into sugar.The vast number of literatures found in the database revealed that the extracts of different parts of jambolan showed significant pharmacological actions.We suggest that there is a need for further investigation to isolate active principles which confer the pharmacological action.Hence identification of such active compounds is useful for producing safer drugs in the treatment of various ailments including diabetes.展开更多
Taking social statistic data as basic data,this paper extended the meaning of urban land uses,highlighted the meaning of urban land uses in modern urbanization,which includes direct,indirect and induced land uses,quan...Taking social statistic data as basic data,this paper extended the meaning of urban land uses,highlighted the meaning of urban land uses in modern urbanization,which includes direct,indirect and induced land uses,quantitatively simulated the indirect and induced land uses by the substitution method of agricultural consumption and urban carbon emission and then,analyzed the spatiotemporal evolution of urban land uses in China during 1952–2005 by spatial analysis tool of Geographic Information System. The results indicate that the area of urban land use in China had been increasing since 1952,showing an inversed pyramid structure,i.e.,the direct<the indirect<the induced. Specifically,Chinese urban land use has changed from concentrated distribution in Northwest China to balanced spatial distribution,and the eastern coastal area is under great pressure. Moreover,the northeastern region has moved into the induced dominant stage,while the western region remains at the indirect dominant stage. Finally,it is proposed that in order to guarantee the future demand of urban land use in China,ensuring the induced land use in the eastern region should be taken as a priority goal of Chinese developing policy.展开更多
In the Sanjiang Plain,Northeast China,the natural wetland is undergoing a rapid conversion into agricultural land,which has resulted in drastic ecological changes in the region. To investigate the effects of different...In the Sanjiang Plain,Northeast China,the natural wetland is undergoing a rapid conversion into agricultural land,which has resulted in drastic ecological changes in the region. To investigate the effects of different land uses on soil labile organic carbon,soils of Calamagrostis angustifolia wetland,Carex lasiocarpa wetland,dry farmland,paddy field,forest land and abandoned cultivated land were collected for measuring the contents of soil microbial biomass carbon (MBC),dissolved organic carbon (DOC),readily oxidizable carbon (ROC) and carbohydrate carbon (CHC). The results show that soil organic carbon contents follow the order: Carex lasiocarpa wetland>Calamagrostis angustifolia wetland>forest land>paddy field>dry farmland. The contents of MBC and DOC in Calamagrostis angustifolia and Carex lasiocarpa wetlands are significantly higher than those in other land use types. The contents of CHC and ROC are the highest in Calamagrostis angustifolia wetland and the lowest in dry farmland. The contents of all the labile organic carbon increase along with the years of abandonment of cultivated land. The ratios of MBC,DOC and ROC to SOC also follow the order: Carex lasiocarpa wetland>Calamagrostis angustifolia wetland>forest land>paddy field>dry farmland,while the ratio of CHC to SOC is paddy field>forest field>Carex lasiocarpa wetland>Carex lasiocarpa wetland>dry farmland. When natural wetlands were cultivated,the activity of soil organic carbon tends to reduce in some extent due to the disappearance of heterotrophic environment and the reduction of vegetation residue. Thus,the abandonment of cultivated land is an effective way for restoring soil organic carbon.展开更多
Soil quality is one of the most important environmental factors in sustaining the global biosphere and developing sustainable agricultural practices. A study was initiated in Wolong Nature Reserve, Sichuan Province, C...Soil quality is one of the most important environmental factors in sustaining the global biosphere and developing sustainable agricultural practices. A study was initiated in Wolong Nature Reserve, Sichuan Province, China to elucidate the soil quality changes of natural secondary succession, forest planting and agricultural practices after deforestation in the humid mountainous region. The soil qualities of six land use types (natural forestland, grassland, shrub land, secondary forestland, cultivated land and reforested land) were compared using two quantitative methods: the integrated soil quality index(QI) and soil deterioration index(DI). The QI values of natural forestland, grassland, shrub land, secondary forestland, cultivated land, reforested land were 0.8039, 0.3277, 0.9127, 0.6881, 0.0285 and 0.3183, respectively. The DI values were 0%, -14%, 12%, 1%, -26% and -18% respectively. Both indexes suggested that shrub land can restore soil properties. To compare the two methods more directly, a deduced index QI′ based on QI value was developed. The results showed that DI and QI′had a very high linear correlation coefficient (r=0.9775) despite the values were different. Both methods were efficient in evaluating the soil quality levels and DI was a more simple way in soil quality assessment, while QI could show more ecological meanings.展开更多
Soil nitrogen pools (NP), denitrification (DN), gross nitrification (GN), N2O and CO2 flux rates with their responses to temperature increases were determined under five different land uses and managements in a subalp...Soil nitrogen pools (NP), denitrification (DN), gross nitrification (GN), N2O and CO2 flux rates with their responses to temperature increases were determined under five different land uses and managements in a subalpine forest-grassland ecotone of the eastern Tibetan Plateau. Land uses consisted of 1) sparse woodland, 2) shrub-land, 3) natural pasture, 4)fenced pasture, and 5) tilled pasture mimicking a gradient degenerating ecosystem under grazing impacts. The NO3--N content was higher than the NH4+-N content. Comparing tilled pasture with fenced pasture showed that higher intensive management (tillage) led to a significant decrease of soil organic matter (SOM) (P < 0.05) in the soils, which was in contrast to the significant increases (P <0.05) of DN, GN, N2O and CO2 flux rates. GN (excluding tilled pasture) and CO2 flux rates increased with a temperature rise, but DN and N2O flux rates normally reached their maximum values at 12-14 ℃ with tilled pasture (the highest management intensity) being very sensitive to temperature increases. There was a difference between net nitrification and GN, with GN being a betterindicator of soil nitrification.展开更多
than 80 Dendrobium species have been reported in China.However,there are only six Dendrobium species,namely,D.bigibbum var.superbum(syn.D.phalaenopsis),D.chrysanthum,D.fimbriatum,D.loddigesii,D.nobile,and D.officinale...than 80 Dendrobium species have been reported in China.However,there are only six Dendrobium species,namely,D.bigibbum var.superbum(syn.D.phalaenopsis),D.chrysanthum,D.fimbriatum,D.loddigesii,D.nobile,and D.officinale(syn.D.candidum),listed in the New Inventory of Existing Cosmetic Ingredients in China Launched.Artificial planting of Dendrobium species has been a great success in China.To better utilize Dendrobium resources for medicinal and cosmetic purposes,we summarize their traditional uses and pharmacologically active compounds for treating dermatological disorders in this review.“Orchidaceae”,“Dendrobium”,“traditional use”,“ethnobotany”,“dermatological disorder”,and“skin disease”were used as search terms to screen the literature.Cited references were collected between 1970 and 2020 from the Web of Science,China National Knowledge Internet(CNKI),SciFinder,Google Scholar,and Chinese books.From the search,it was found that there are 22 Dendrobium species with traditional uses in dermatological disorders,and 131 compounds from Dendrobium plants have been reported to possess anti-inflammatory,antimicrobial,antioxidant,antiaging,anti-psoriasis,and tyrosinase-inhibitory activities,implying that Dendrobium plants are important resources for the discovery of active compounds and the development of new drugs and cosmetics.D.crepidatum,D.denneanum,D.loddigesii,D.nobile,and D.officinale have been extensively studied.More research on other Dendrobium species is needed.The major active compounds found in Dendrobium species are phenanthrenes,alkaloids,flavonoids,phenylpropanoids,and lignans.Several compounds,such as loddigesiinol A,(S)-5-methoxy-2,4,7,9-tetrahydroxy-9,10-dihydrophenanthrene,(S)-4-methoxy-2,5,7,9-tetrahydroxy-9,10-dihydrophenanthrene,2,5-dihydroxy-4-methoxy-phenanthrene 2-O-β-d-glucopyranoside,(9R)-1,2,5,9-tetrahydroxy-9,10-dihydrophenanthrene 5-O-β-d-glucopyranoside,(+)-homocrepidine A,and vicenin 2,have significant anti-inflammatory activities and inhibit nitric oxide(NO)production with IC_(50) values less than 5μM,and these compounds are worthy of further study.展开更多
Quantification of soil spatial and temporal variability at watershed scale is important in ecological modeling, precision agriculture, and natural resources management. The spatio-temporal variations of soil nitrogen ...Quantification of soil spatial and temporal variability at watershed scale is important in ecological modeling, precision agriculture, and natural resources management. The spatio-temporal variations of soil nitrogen under different land uses in a small watershed (12.10 km^2) in the hilly area of purple soil at the upper reaches of the Yangtze River in southwestern China were investigated by using conventional statistics, geostatistics, and a geographical information system in order to provide information for land management and control of environmental issues. A total of 552 soil samples (o to 15 cm) from 276 sites within the watershed were collected in April and August of 2o11, and analyzed for soil total nitrogen (STN) and nitrate nitrogen (NO3-N). We compared spatial variations of STN and NO3-N under different land uses as well as the temporal variations in April (dry season) and August (rainy season). Results showed that STN contents were deeply affected by land-use types; median STN values ranged from 0.94to 1.27g.kg-I, and STN contents decreased in the following order: paddy field 〉 foresfland 〉 sloping cropland. No significant difference was found for STN contents between April and August under the same land use. However, NO3- N contents were 23.26, 10.58, and 26.19 mg·kg^-1 in April, and 1.34, 8.51, and 3.00 mg·kg^-1 in August for the paddy field, sloping cropland and forestland, respectively. Nugget ratios for STN indicatedmoderate spatial dependence in the paddy field and sloping cropland, and a strong spatial dependence in forestland. The processes of nitrogen movement, transformation, absorption of plant were deeply influenced by land use types; as a result, great changes of soil nitrogen levels at spatial and temporal scales were demonstrated in the studied watershed.展开更多
The vertical distribution of the dominant genera of plant nematodes at the depth of 0–150 cm of an aquic brown soil were studied for four land use patterns, i.e., paddy field, maize field, fallow field and woodland i...The vertical distribution of the dominant genera of plant nematodes at the depth of 0–150 cm of an aquic brown soil were studied for four land use patterns, i.e., paddy field, maize field, fallow field and woodland in the Shenyang Experimental Station of Ecology, Chi- nese Academy of Sciences in November of 2003. The results showed that the numbers of some dominant genera under different land uses decreased with the increase of soil depth. Helicotylenchus was most dominant genus under each land use type. Genera of Filenchus, Psilen- chus and Tylenchus in paddy field occurred at the depth of 0–20 cm; while Paratylenchus in fallow field and woodland, as well as Praty- lenchus in maize field presented in the deeper soil layers (0–80 cm). Significant correlations between the numbers of dominant genera of plant nematodes and soil chemical properties were found in this study. The number of Helicotylenchus under different land uses was posi- tively correlated with C/N ratio, total C, total N, total P, alkai-N, and Olsen-P. The numbers of Filenchus and Paratylenchus in paddy field, Pratylenchus in maize field and Paratylenchus in fallow field were negatively correlated with soil pH, and positively correlated with total C, total N and alkai-N. This study results showed that it is essential to sample at a certain depth according to the vertical distribution informa- tion of different genera of plant nematodes in adequately assessing the population size of plant nematodes.展开更多
The present review is intended to provide information on botany,ethnomedicinal uses,phytochemistry and biological activities of various parts of Euphorbia neriifolia(E. neriifolia). E. neriifolia has several ethnomedi...The present review is intended to provide information on botany,ethnomedicinal uses,phytochemistry and biological activities of various parts of Euphorbia neriifolia(E. neriifolia). E. neriifolia has several ethnomedicinal uses. The latex of E. neriifolia is used as laxative,purgative,rubefacient,carminative and expectorant as well as in treatment of whooping cough,gonorrhea,leprosy,asthma,dyspepsia,jaundice,enlargement of the spleen,tumors,stone in the bladder,abdominal troubles and leucoderma. Leaves are brittle,heating,carminative,and good for improving the appetite and treatment of tumors,pains,inflammations,abdominal swellings and bronchial infections. Roots are used as symptomatic treatment of snake bite,scorpion sting and antispasmodic. Various plant parts or whole E. neriifolia extract and its isolates have been reported scientifically using various in-vivo and in-vitro experimental methods for anaesthetic,analgesic,anti-anxiety,anti-convulsant,anti-psychotic,anti-arthritis,anti-carcinogenic,antidiabetic,anti-diarrhoeal,anti-inflammatory,anti-thrombotic,antimicrobial,antioxidant,antiulcer,cytotoxic,death-receptor expression enhancing,dermal irritation,diuretic,hemolytic,immunomodulatory,radioprotective,scorpion venom and wound healing properties. It is reported to have chemical constituents like,neriifolin-S,neriifolin,neriifoliene,euphol,neriifolione,cycloartenol,nerifoliol,lectin,euphonerins A–G,3-O-acetyl-8-O-tigloylingol,taraxerol,antiquorin,etc. Identified chemical constituents are still required to be explored for their advanced isolation techniques and biological activities.展开更多
During the last decade of the 20th century, extensive conversion inagricultural land use took place in Northeast China. The goal of this study is to ascertain itsspatial distribution and regional differentiation, dete...During the last decade of the 20th century, extensive conversion inagricultural land use took place in Northeast China. The goal of this study is to ascertain itsspatial distribution and regional differentiation, determine its causes, and analyze itsenvironmental impact. Especially we attempt to elucidate how institutional constraints havefacilitated the change at a time of agrarian restructuring when newly emerging free market washybridized with the former planned economy. Information on six categories of land use was mappedfrom interpretation of Landsat TM images recorded in 1990, 1995 and 2000. Most of land use changestook place during the first half of the decade, coinciding with abrupt and chaotic changes ingovernment directives. Farmland was changed mainly to woodland, water body and built-up areas whilewoodland and grassland were converted chiefly to farmland. Spatially, the change from farmland towoodland was restricted to the west of the study area. The change from grassland to farmland tookplace in the grazing and farming interlocked west. These chaotic and occasionally conflictingchanges were largely caused by lack of stability and consistency in agricultural land use policiespromulgated. They have exerted adverse impacts on the local environment, including land degradation,increased flooding, and modified climate regime.展开更多
One of the most important functions of soils is to regulate rainwater and mitigate flooding and associated damages; this function can be estimated by the rainwater regulation ratio (η), i.e., percent of regulated r...One of the most important functions of soils is to regulate rainwater and mitigate flooding and associated damages; this function can be estimated by the rainwater regulation ratio (η), i.e., percent of regulated rainwater. Fifteen experimental plots were set up on the hills in Yingtan of Jiangxi Province, southern China. These plots were under three land use patterns, cultivated cropland, noncultivated land, and orchard interplanted with cash crops. With aid of an artificial rainfall simulator and Guelph method, rainfall, runoff, soil infiltration, and so on were measured in situ. Results showed that the orchard interplanted with cash crops was more effective in regulating rainwater than the other two land use patterns. When the maximum infiltration intensity was three times higher than the observed mean,η was higher than 70% for all plots. 77 was related to land use, slope gradient, and soil properties such as soil infiltration, organic carbon, bulk density, and texture. There is still more room to improve capacity of rainwater drainage (underground percolation) than that of rainwater storage in soils. Therefore, enhancing soil permeability is vital to improve the rainwater regulation efficiency in soils.展开更多
Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small water...Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small watershed of subtropical region of China was selected for this study. Land uses covered paddy fields, vegetable farming, fruit trees, upland crops, bamboo stands, and forestry. Soil biological and biochemical properties included soil organic C and nutrient contents, mineralization of soil organic C, and soil microbial biomass and community functional diversity. Soil organic C and total N contents, microbial biomass C and N, and respiration intensity under different land uses were changed in the following order: paddy fields (and vegetable farming) 〉 bamboo stands 〉 fruit trccs (and upland). The top surface (0-15 cm) paddy fields (and vegetable farming) were 76.4 and 80.8% higher in soil organic C and total N contents than fruit trees (and upland) soils, respectively. Subsurface paddy soils (15-30 cm) were 59.8 and 67.3% higher in organic C and total N than upland soils, respectively. Soil microbial C, N and respiration intensity in paddy soils (0-15 cm) were 6.36, 3.63 and 3.20 times those in fruit tree (and upland) soils respectively. Soil microbial metabolic quotient was in the order: fruit trees (and upland) 〉 forestry 〉 paddy fields. Metabolic quotient in paddy soils was only 47.7% of that in fruit tree (and upland) soils. Rates of soil organic C mineralization during incubation changed in the order: paddy fields 〉 bamboo stands 〉 fruit trees (and upland) and soil bacteria population: paddy fields 〉 fruit trees (and upland) 〉 forestry. No significant difference was found for fungi and actinomycetes populations. BIOLOG analysis indicated a changing order of paddy fields 〉 fruit trees (and upland) 〉 forestry in values of the average well cell development (AWCD) and functional diversity indexes of microbial community. Results also showed that the conversion from paddy fields to vegetable farming for 5 years resulted in a dramatic increase in soil available phosphorus content while insignificant changes in soil organic C and total N content due to a large inputs of phosphate fertilizers. This conversion caused 53, 41.5, and 41.3% decreases in soil microbial biomass C, N, and respiration intensity, respectively, while 23.6% increase in metabolic quotient and a decrease in soil organic C mineralization rate. Moreover, soil bacteria and actinomycetes populations were increased slightly, while fungi population increased dramatically. Functional diversity indexes of soil microbial community decreased significantly. It was concluded that land uses in the subtropical region of China strongly affected soil biological and biochemical properties. Soil organic C and nutrient contents, mineralization of organic C and functional diversity of microbial community in paddy fields were higher than those in upland and forestry. Overuse of chemical fertilizers in paddy fields with high fertility might degrade soil biological properties and biochemical function, resulting in deterioration of soil biological quality.展开更多
Objective:To document ethnobotanical informations of useful woody plant species in the region of Kotli,Azad Kashmir.Methods:An ethnobotanical survey was conducted in Kotli.Data were collected by interview and semi str...Objective:To document ethnobotanical informations of useful woody plant species in the region of Kotli,Azad Kashmir.Methods:An ethnobotanical survey was conducted in Kotli.Data were collected by interview and semi structured questionnaire from selected local informants and traditional practitioners as well as by field assessment.Results:The present study documented the etnobotanical uses of 33 woody plant species.Most of the species have been used for dual purpose.Only 5 species are used for one purpose.Study revealed all species have medicinal value,among which 21 were used as fuel wood species,16 as fodder species,4 as timber wood species,12 as edible fruit species,6 as fence or hedge plant,7 as ornamental species and 12 species had other uses.Conclusions:Medicinal plants are still widely used for health care by locals of Kotli.Some species of woodlands seem to be vulnerable to overcollection and deforestation.As the young generation is diverted toward allelopathic medicines,ethnobotanical knowledges of important medicinal plants are restricted to the old people only.It is suggested to close the forest of district Kotli for next two to three decades for the conservation of plant biodiversity.展开更多
文摘The Annapurna Conservation Area (ACA), the first conservation area and the largest protected area (PA) in Nepal, is incredibly rich in biodiversity. Notwithstanding this, orchids in the ACA have not been explored enough yet thus making the need for ambitious research to be carried out. Previous study only included 81 species of orchids within ACA. This study aims to update the record of species and genera richness in the ACA. In total 198 species of orchids, belonging to 67 genera (40% and 62% of the total recorded orchid species and genera in Nepal) has been recorded in ACA. This represents an increase of 144% in species and 56% in genera over the previous data. Out of the 198 species, 99 were epiphytes, 6 were holomycotrophic and 93 were terrestrial. Among the 67 genera, Bulbophyllum (17) species were dominant, followed by Dendrobium (16), Herminium (10), Coelogyne, Plantanthera (9 each), Eria, Habenaria, Oberonia (8 each), Calanthe (7), and Liparis (6). Fifty-six species were found to be ornamentally significant and 85 species medicinally significant.
基金funded by the National Natural Science Foundation of China(42101264,42101200)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(CPSF)(GZC20233314)+1 种基金the Chongqing Natural Science Foundation,China(cstc2021jcyj-msxmX0811)the Fundamental Research Funds for the Central Universities,China(2023CDSKXYGG006,2024CDJXY014).
文摘Land use conflicts(LUCs),as a spatial manifestation of the conflicts in the human-land relationships,have a profound impact on regional sustainable development.For China’s metropolitan junction areas(MJAs),the existence of“administrative district economies”has made the issue of LUCs more prominent.Based on a case study of the central Chengdu–Chongqing region,we conducted an exploratory spatial data analysis of the evolutionary process of regional LUCs.Furthermore,structural equation modeling was utilized to analyze the dynamic mechanism of LUCs in MJAs,with a particular emphasis on exploring the influences of administrative boundary.The results showed that from 2010 to 2020,LUCs in the central Chengdu–Chongqing region continued to worsen,and the spatial process conflict and spatial structure conflict indices increased by more than 30.0%.The intensification of LUCs in the central Chengdu–Chongqing region from 2010 to 2020 was mainly the result of the deterioration of conflicts in evaluation units with low conflict levels.LUCs in China’s metropolitan areas generally presented a circular gradient distribution,weakening from the core to the periphery,but there were some strong isolated conflict zones in the outer regions.LUCs in China’s MJAs were the result of interactions among multiple factors,e.g.,natural environment,socio-economic development,policy and institutional processes,and administrative boundary effects.Administrative boundary affected the flow of socio-economic elements,changing the supply-and-demand competition of stakeholders for land resources,consequently exerting an indirect influence on LUCs.This study advances the theory of the dynamic mechanism of LUCs,and provides theoretical support for the governance of these conflicts in transboundary areas.
文摘This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the study, namely Mangoum, Makeka and Fossang, representative of the three dominant soil types of the noun plain (Andosols, Acrisols and Ferralsols). Three land uses were selected per site including natural vegetation, agroforest and crop field. Soil was sampled at three depths;0 - 20 cm, 20 - 40 cm, and 40 - 60 cm. Analysis of variance showed that soil type did not significantly influence carbon storage, but rather land uses and soil depth. SOCS decreased significantly with depth in all the sites, with an average stock of 66.3 ± 15.8 tC/ha at 0 - 20 cm, compared to an average stock of 33.3 ± 7.4 tC/ha at 40 - 60 cm. SOCS was significantly highest in the natural formation with 57.2 ± 19.7 tC/ha, and lowest in cultivated fields, at 37.7 ± 10.6 tC/ha. Andosols, with their high content of coarse fragments, stored less organic carbon than Ferralsols and Acrisols.
文摘The vertical variation and storage of nitrogen in the depth of 0-150 cm of an aquic brown soil were studied under 14 years of four land use patterns, i.e., paddy field, maize field, fallow field and woodland in Shenyang Experimental Station of Ecology, Chinese Academy of Sciences in November of 2003. The results showed that different land uses had different profile distributions of soil total nitrogen (STN), alkali N, ammonium (NH4+-N) and nitrate (NO3--N). The sequence of STN storage was woodland >maize field > fallow field > paddy field, while that of NO3--N content was maize field > paddy field > woodland > fallow field, suggesting the different root biomass and biological N cycling under various land uses. The STN storage in the depth of 0-100 cm of woodland averaged to 11.41 thm-1, being 1.65 and 1.25 times as much as that in paddy and maize fields, respec-tively, while there was no significant difference between maize and fallow fields. The comparatively higher amount of NO3--N in maize and paddy fields may be due to nitrogen fertilization and anthropogenic disturbance. Soil alkali N was significantly related with STN, and the correlation could be expressed by a linear regression model under each land use (R20.929, p<0.001). Such a correlation was slightly closer in nature (woodland and fallow field) than in agro ecosystems (paddy and maize fields). Heavy N fertilization induced an excess of crop need, and led to a comparatively higher amount of soil NO3--N in cultivated fields than in fallow field and woodland. It is suggested that agroforestry practices have the potential to make a significant contribution to both crop production and environment protection.
基金Supported by the National Scientific Foundation of China(70873118 70821140353 )+4 种基金the Chinese Academy of Sciences(KZCX2-YW-305-2 KZCX2-YW-326-1)the Ministry of Science and Technology of China ( 2006DFB919201 2008BAC43B012008BAK47B02)~~
文摘The robust principal component analysis (RPCA) is a technique of multivariate statistics to assess the social and economic environment quality. This paper aims to explore a RPCA algorithm to analyze the spatial heterogeneity of social and economic environment of land uses (SEELU). RPCA supplies one of the most efficient methods to derive the most important components or factors affecting the regional difference of the social and economic environment. According to the spatial distributions of the levels of SEELU,the total land resources of China were divided into eight zones numbered by Ⅰ to Ⅷ which spatially referred to the eight levels of SEELU.
文摘The chemical constituents, pharmacological activity and traditional uses of 20 species attributed to the genus Elsholtzia (Labiatae) used in China are reviewed and compared. A survey of the literature available shows that these species are used mostly for the treatment of respiratory and gastrointestinal disorders. Additionally, some of these Elsholtzia species show antibacterial, anti-inflammatory, relieving fever, analgesic activities and myocardial ischemia protection. Generally, the essential oils or flavonoids from these plant extracts are assumed to be the active principles.
文摘Clinacanthus nutans Lindau is known as snake grass belonging to the Acanlhaceae family.This plant has diverse and potential medicinal uses in traditional herbal medicine for treating skin rashes,insects and snake bites,lesions caused by herpes simplex virus,diabetes,and gout in Malaysia.Indonesia.Thailand and China.Phylochemieal investigations documented the varied contents of bioaclive compounds from litis plant namely flavonoids,glycosides,glycoglyeerolipids.cerebrosides and monoacylmonogalatosylglycerol.The pharmacological experiment proved that various types of extracts and pure compounds from this species exhibited a broad range of biological properties such as anti-inflammatory,antiviral,antioxidant,and anti-diabetic activities.The lindings of toxicity study showed that extracts from this plant did not show any toxicity thus it can be used as strong therapeutic agents for specific diseased conditions.However,further experiments on chemical components and their mode of action showing biological activities are required to elucidate the complete phytochemical profile and assess to confirm their suitability tor future drugs.This review summarizes the medicinal uses,phytochemistry and pharmacology of this plant in order to explore its therapeutic potential and gaps necessitating for prospected research work.
基金fianancially supported by University Grants Commission,New Delhi[grant No.F.4-2/2006(BSR)/13-98/2008(BSR)]
文摘Syzygium cumini(S.cumini)(L.) Skeels(jambolan) is one of the widely used medicinal plants in the treatment of various diseases in particular diabetes.The present review has been primed to describe the existing data on the information on botany,phytochemical constituents,traditional uses and pharmacological actions of 5.cumini(L.) Skeels(jambolan).Electronic database search was conducted with the search terms of Eugenia jambolana,S.cumini,jambolan,common plum and java plum.The plant has been viewed as an antidiabetic plant since it became commercially available several decades ago.During last four decades,numerous folk medicine and scientific reports on the antidiabetic effects of this plant have been cited in the literature.The plant is rich in compounds containing anthocyanins,glucoside,ellagic acid,isoquercetin,kaemferol and myrecetin.The seeds are claimed to contain alkaloid,jambosine,and glycoside jambolin or antimellin,which halts the diastalic conversion of starch into sugar.The vast number of literatures found in the database revealed that the extracts of different parts of jambolan showed significant pharmacological actions.We suggest that there is a need for further investigation to isolate active principles which confer the pharmacological action.Hence identification of such active compounds is useful for producing safer drugs in the treatment of various ailments including diabetes.
基金Under the auspices of Key Program of National Natural Science Foundation of China (No. 40535026)
文摘Taking social statistic data as basic data,this paper extended the meaning of urban land uses,highlighted the meaning of urban land uses in modern urbanization,which includes direct,indirect and induced land uses,quantitatively simulated the indirect and induced land uses by the substitution method of agricultural consumption and urban carbon emission and then,analyzed the spatiotemporal evolution of urban land uses in China during 1952–2005 by spatial analysis tool of Geographic Information System. The results indicate that the area of urban land use in China had been increasing since 1952,showing an inversed pyramid structure,i.e.,the direct<the indirect<the induced. Specifically,Chinese urban land use has changed from concentrated distribution in Northwest China to balanced spatial distribution,and the eastern coastal area is under great pressure. Moreover,the northeastern region has moved into the induced dominant stage,while the western region remains at the indirect dominant stage. Finally,it is proposed that in order to guarantee the future demand of urban land use in China,ensuring the induced land use in the eastern region should be taken as a priority goal of Chinese developing policy.
基金Under the auspices of National Natural Science Foundation of China (No. 30470340)
文摘In the Sanjiang Plain,Northeast China,the natural wetland is undergoing a rapid conversion into agricultural land,which has resulted in drastic ecological changes in the region. To investigate the effects of different land uses on soil labile organic carbon,soils of Calamagrostis angustifolia wetland,Carex lasiocarpa wetland,dry farmland,paddy field,forest land and abandoned cultivated land were collected for measuring the contents of soil microbial biomass carbon (MBC),dissolved organic carbon (DOC),readily oxidizable carbon (ROC) and carbohydrate carbon (CHC). The results show that soil organic carbon contents follow the order: Carex lasiocarpa wetland>Calamagrostis angustifolia wetland>forest land>paddy field>dry farmland. The contents of MBC and DOC in Calamagrostis angustifolia and Carex lasiocarpa wetlands are significantly higher than those in other land use types. The contents of CHC and ROC are the highest in Calamagrostis angustifolia wetland and the lowest in dry farmland. The contents of all the labile organic carbon increase along with the years of abandonment of cultivated land. The ratios of MBC,DOC and ROC to SOC also follow the order: Carex lasiocarpa wetland>Calamagrostis angustifolia wetland>forest land>paddy field>dry farmland,while the ratio of CHC to SOC is paddy field>forest field>Carex lasiocarpa wetland>Carex lasiocarpa wetland>dry farmland. When natural wetlands were cultivated,the activity of soil organic carbon tends to reduce in some extent due to the disappearance of heterotrophic environment and the reduction of vegetation residue. Thus,the abandonment of cultivated land is an effective way for restoring soil organic carbon.
文摘Soil quality is one of the most important environmental factors in sustaining the global biosphere and developing sustainable agricultural practices. A study was initiated in Wolong Nature Reserve, Sichuan Province, China to elucidate the soil quality changes of natural secondary succession, forest planting and agricultural practices after deforestation in the humid mountainous region. The soil qualities of six land use types (natural forestland, grassland, shrub land, secondary forestland, cultivated land and reforested land) were compared using two quantitative methods: the integrated soil quality index(QI) and soil deterioration index(DI). The QI values of natural forestland, grassland, shrub land, secondary forestland, cultivated land, reforested land were 0.8039, 0.3277, 0.9127, 0.6881, 0.0285 and 0.3183, respectively. The DI values were 0%, -14%, 12%, 1%, -26% and -18% respectively. Both indexes suggested that shrub land can restore soil properties. To compare the two methods more directly, a deduced index QI′ based on QI value was developed. The results showed that DI and QI′had a very high linear correlation coefficient (r=0.9775) despite the values were different. Both methods were efficient in evaluating the soil quality levels and DI was a more simple way in soil quality assessment, while QI could show more ecological meanings.
文摘Soil nitrogen pools (NP), denitrification (DN), gross nitrification (GN), N2O and CO2 flux rates with their responses to temperature increases were determined under five different land uses and managements in a subalpine forest-grassland ecotone of the eastern Tibetan Plateau. Land uses consisted of 1) sparse woodland, 2) shrub-land, 3) natural pasture, 4)fenced pasture, and 5) tilled pasture mimicking a gradient degenerating ecosystem under grazing impacts. The NO3--N content was higher than the NH4+-N content. Comparing tilled pasture with fenced pasture showed that higher intensive management (tillage) led to a significant decrease of soil organic matter (SOM) (P < 0.05) in the soils, which was in contrast to the significant increases (P <0.05) of DN, GN, N2O and CO2 flux rates. GN (excluding tilled pasture) and CO2 flux rates increased with a temperature rise, but DN and N2O flux rates normally reached their maximum values at 12-14 ℃ with tilled pasture (the highest management intensity) being very sensitive to temperature increases. There was a difference between net nitrification and GN, with GN being a betterindicator of soil nitrification.
文摘than 80 Dendrobium species have been reported in China.However,there are only six Dendrobium species,namely,D.bigibbum var.superbum(syn.D.phalaenopsis),D.chrysanthum,D.fimbriatum,D.loddigesii,D.nobile,and D.officinale(syn.D.candidum),listed in the New Inventory of Existing Cosmetic Ingredients in China Launched.Artificial planting of Dendrobium species has been a great success in China.To better utilize Dendrobium resources for medicinal and cosmetic purposes,we summarize their traditional uses and pharmacologically active compounds for treating dermatological disorders in this review.“Orchidaceae”,“Dendrobium”,“traditional use”,“ethnobotany”,“dermatological disorder”,and“skin disease”were used as search terms to screen the literature.Cited references were collected between 1970 and 2020 from the Web of Science,China National Knowledge Internet(CNKI),SciFinder,Google Scholar,and Chinese books.From the search,it was found that there are 22 Dendrobium species with traditional uses in dermatological disorders,and 131 compounds from Dendrobium plants have been reported to possess anti-inflammatory,antimicrobial,antioxidant,antiaging,anti-psoriasis,and tyrosinase-inhibitory activities,implying that Dendrobium plants are important resources for the discovery of active compounds and the development of new drugs and cosmetics.D.crepidatum,D.denneanum,D.loddigesii,D.nobile,and D.officinale have been extensively studied.More research on other Dendrobium species is needed.The major active compounds found in Dendrobium species are phenanthrenes,alkaloids,flavonoids,phenylpropanoids,and lignans.Several compounds,such as loddigesiinol A,(S)-5-methoxy-2,4,7,9-tetrahydroxy-9,10-dihydrophenanthrene,(S)-4-methoxy-2,5,7,9-tetrahydroxy-9,10-dihydrophenanthrene,2,5-dihydroxy-4-methoxy-phenanthrene 2-O-β-d-glucopyranoside,(9R)-1,2,5,9-tetrahydroxy-9,10-dihydrophenanthrene 5-O-β-d-glucopyranoside,(+)-homocrepidine A,and vicenin 2,have significant anti-inflammatory activities and inhibit nitric oxide(NO)production with IC_(50) values less than 5μM,and these compounds are worthy of further study.
基金this project was provided by the Natural Science Foundation of China (Grant No.41271321)the National Key Basic Research Program of China (Grant no. 2012CB417101)
文摘Quantification of soil spatial and temporal variability at watershed scale is important in ecological modeling, precision agriculture, and natural resources management. The spatio-temporal variations of soil nitrogen under different land uses in a small watershed (12.10 km^2) in the hilly area of purple soil at the upper reaches of the Yangtze River in southwestern China were investigated by using conventional statistics, geostatistics, and a geographical information system in order to provide information for land management and control of environmental issues. A total of 552 soil samples (o to 15 cm) from 276 sites within the watershed were collected in April and August of 2o11, and analyzed for soil total nitrogen (STN) and nitrate nitrogen (NO3-N). We compared spatial variations of STN and NO3-N under different land uses as well as the temporal variations in April (dry season) and August (rainy season). Results showed that STN contents were deeply affected by land-use types; median STN values ranged from 0.94to 1.27g.kg-I, and STN contents decreased in the following order: paddy field 〉 foresfland 〉 sloping cropland. No significant difference was found for STN contents between April and August under the same land use. However, NO3- N contents were 23.26, 10.58, and 26.19 mg·kg^-1 in April, and 1.34, 8.51, and 3.00 mg·kg^-1 in August for the paddy field, sloping cropland and forestland, respectively. Nugget ratios for STN indicatedmoderate spatial dependence in the paddy field and sloping cropland, and a strong spatial dependence in forestland. The processes of nitrogen movement, transformation, absorption of plant were deeply influenced by land use types; as a result, great changes of soil nitrogen levels at spatial and temporal scales were demonstrated in the studied watershed.
文摘The vertical distribution of the dominant genera of plant nematodes at the depth of 0–150 cm of an aquic brown soil were studied for four land use patterns, i.e., paddy field, maize field, fallow field and woodland in the Shenyang Experimental Station of Ecology, Chi- nese Academy of Sciences in November of 2003. The results showed that the numbers of some dominant genera under different land uses decreased with the increase of soil depth. Helicotylenchus was most dominant genus under each land use type. Genera of Filenchus, Psilen- chus and Tylenchus in paddy field occurred at the depth of 0–20 cm; while Paratylenchus in fallow field and woodland, as well as Praty- lenchus in maize field presented in the deeper soil layers (0–80 cm). Significant correlations between the numbers of dominant genera of plant nematodes and soil chemical properties were found in this study. The number of Helicotylenchus under different land uses was posi- tively correlated with C/N ratio, total C, total N, total P, alkai-N, and Olsen-P. The numbers of Filenchus and Paratylenchus in paddy field, Pratylenchus in maize field and Paratylenchus in fallow field were negatively correlated with soil pH, and positively correlated with total C, total N and alkai-N. This study results showed that it is essential to sample at a certain depth according to the vertical distribution informa- tion of different genera of plant nematodes in adequately assessing the population size of plant nematodes.
文摘The present review is intended to provide information on botany,ethnomedicinal uses,phytochemistry and biological activities of various parts of Euphorbia neriifolia(E. neriifolia). E. neriifolia has several ethnomedicinal uses. The latex of E. neriifolia is used as laxative,purgative,rubefacient,carminative and expectorant as well as in treatment of whooping cough,gonorrhea,leprosy,asthma,dyspepsia,jaundice,enlargement of the spleen,tumors,stone in the bladder,abdominal troubles and leucoderma. Leaves are brittle,heating,carminative,and good for improving the appetite and treatment of tumors,pains,inflammations,abdominal swellings and bronchial infections. Roots are used as symptomatic treatment of snake bite,scorpion sting and antispasmodic. Various plant parts or whole E. neriifolia extract and its isolates have been reported scientifically using various in-vivo and in-vitro experimental methods for anaesthetic,analgesic,anti-anxiety,anti-convulsant,anti-psychotic,anti-arthritis,anti-carcinogenic,antidiabetic,anti-diarrhoeal,anti-inflammatory,anti-thrombotic,antimicrobial,antioxidant,antiulcer,cytotoxic,death-receptor expression enhancing,dermal irritation,diuretic,hemolytic,immunomodulatory,radioprotective,scorpion venom and wound healing properties. It is reported to have chemical constituents like,neriifolin-S,neriifolin,neriifoliene,euphol,neriifolione,cycloartenol,nerifoliol,lectin,euphonerins A–G,3-O-acetyl-8-O-tigloylingol,taraxerol,antiquorin,etc. Identified chemical constituents are still required to be explored for their advanced isolation techniques and biological activities.
文摘During the last decade of the 20th century, extensive conversion inagricultural land use took place in Northeast China. The goal of this study is to ascertain itsspatial distribution and regional differentiation, determine its causes, and analyze itsenvironmental impact. Especially we attempt to elucidate how institutional constraints havefacilitated the change at a time of agrarian restructuring when newly emerging free market washybridized with the former planned economy. Information on six categories of land use was mappedfrom interpretation of Landsat TM images recorded in 1990, 1995 and 2000. Most of land use changestook place during the first half of the decade, coinciding with abrupt and chaotic changes ingovernment directives. Farmland was changed mainly to woodland, water body and built-up areas whilewoodland and grassland were converted chiefly to farmland. Spatially, the change from farmland towoodland was restricted to the west of the study area. The change from grassland to farmland tookplace in the grazing and farming interlocked west. These chaotic and occasionally conflictingchanges were largely caused by lack of stability and consistency in agricultural land use policiespromulgated. They have exerted adverse impacts on the local environment, including land degradation,increased flooding, and modified climate regime.
基金the National Key Basic Research Support Foundation of China (No.2007CB407206) the National Natural Science Foundation of China (No.40471081).
文摘One of the most important functions of soils is to regulate rainwater and mitigate flooding and associated damages; this function can be estimated by the rainwater regulation ratio (η), i.e., percent of regulated rainwater. Fifteen experimental plots were set up on the hills in Yingtan of Jiangxi Province, southern China. These plots were under three land use patterns, cultivated cropland, noncultivated land, and orchard interplanted with cash crops. With aid of an artificial rainfall simulator and Guelph method, rainfall, runoff, soil infiltration, and so on were measured in situ. Results showed that the orchard interplanted with cash crops was more effective in regulating rainwater than the other two land use patterns. When the maximum infiltration intensity was three times higher than the observed mean,η was higher than 70% for all plots. 77 was related to land use, slope gradient, and soil properties such as soil infiltration, organic carbon, bulk density, and texture. There is still more room to improve capacity of rainwater drainage (underground percolation) than that of rainwater storage in soils. Therefore, enhancing soil permeability is vital to improve the rainwater regulation efficiency in soils.
基金the National Natural Science Foundation of China (40471066) the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX3-SW-417).
文摘Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small watershed of subtropical region of China was selected for this study. Land uses covered paddy fields, vegetable farming, fruit trees, upland crops, bamboo stands, and forestry. Soil biological and biochemical properties included soil organic C and nutrient contents, mineralization of soil organic C, and soil microbial biomass and community functional diversity. Soil organic C and total N contents, microbial biomass C and N, and respiration intensity under different land uses were changed in the following order: paddy fields (and vegetable farming) 〉 bamboo stands 〉 fruit trccs (and upland). The top surface (0-15 cm) paddy fields (and vegetable farming) were 76.4 and 80.8% higher in soil organic C and total N contents than fruit trees (and upland) soils, respectively. Subsurface paddy soils (15-30 cm) were 59.8 and 67.3% higher in organic C and total N than upland soils, respectively. Soil microbial C, N and respiration intensity in paddy soils (0-15 cm) were 6.36, 3.63 and 3.20 times those in fruit tree (and upland) soils respectively. Soil microbial metabolic quotient was in the order: fruit trees (and upland) 〉 forestry 〉 paddy fields. Metabolic quotient in paddy soils was only 47.7% of that in fruit tree (and upland) soils. Rates of soil organic C mineralization during incubation changed in the order: paddy fields 〉 bamboo stands 〉 fruit trees (and upland) and soil bacteria population: paddy fields 〉 fruit trees (and upland) 〉 forestry. No significant difference was found for fungi and actinomycetes populations. BIOLOG analysis indicated a changing order of paddy fields 〉 fruit trees (and upland) 〉 forestry in values of the average well cell development (AWCD) and functional diversity indexes of microbial community. Results also showed that the conversion from paddy fields to vegetable farming for 5 years resulted in a dramatic increase in soil available phosphorus content while insignificant changes in soil organic C and total N content due to a large inputs of phosphate fertilizers. This conversion caused 53, 41.5, and 41.3% decreases in soil microbial biomass C, N, and respiration intensity, respectively, while 23.6% increase in metabolic quotient and a decrease in soil organic C mineralization rate. Moreover, soil bacteria and actinomycetes populations were increased slightly, while fungi population increased dramatically. Functional diversity indexes of soil microbial community decreased significantly. It was concluded that land uses in the subtropical region of China strongly affected soil biological and biochemical properties. Soil organic C and nutrient contents, mineralization of organic C and functional diversity of microbial community in paddy fields were higher than those in upland and forestry. Overuse of chemical fertilizers in paddy fields with high fertility might degrade soil biological properties and biochemical function, resulting in deterioration of soil biological quality.
文摘Objective:To document ethnobotanical informations of useful woody plant species in the region of Kotli,Azad Kashmir.Methods:An ethnobotanical survey was conducted in Kotli.Data were collected by interview and semi structured questionnaire from selected local informants and traditional practitioners as well as by field assessment.Results:The present study documented the etnobotanical uses of 33 woody plant species.Most of the species have been used for dual purpose.Only 5 species are used for one purpose.Study revealed all species have medicinal value,among which 21 were used as fuel wood species,16 as fodder species,4 as timber wood species,12 as edible fruit species,6 as fence or hedge plant,7 as ornamental species and 12 species had other uses.Conclusions:Medicinal plants are still widely used for health care by locals of Kotli.Some species of woodlands seem to be vulnerable to overcollection and deforestation.As the young generation is diverted toward allelopathic medicines,ethnobotanical knowledges of important medicinal plants are restricted to the old people only.It is suggested to close the forest of district Kotli for next two to three decades for the conservation of plant biodiversity.