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The direct cutting natural grass and vetiver grass (Vetiveria zizanioides) and the washing undisturbed soil experiments were used to analyze the soil erosion effect of their root system at the slope of 3° and 25° of purple soil. Results showed that: 1) The vetiver root system altered the soil structure, indicating that the soil bulk density was significantly negative correlated with root length density and surface area density (Pvetiver grass 25°>natural grass grass 3°>natural grass 25°; On different experimental plot, soil antiscouribility index showed as vetiver grass 3° >vetiver grass 25° >natural grass 3°>natural grass 25°; 4) Compared with the natural grass, soil structure with vetiver was more stable, and had stronger ability of shear strength and soil antiscouribility; And the vetiver showed the soil erosion effect in sloping cropland of 3° and 25°.
In this study, Agropyron mongolicum and Lespedeza davurica were single sowing, peer mixed sowing and peer mixed sowing in shrub land at Sidunzi experimental base, Yanchi county, Ningxia, to study the effect of sowing methods on pasture biomass and available nutrient distribution of soil. The result showed that aboveground biomass rank from high to low were peer mixed pasture>single sowing A. mongolicum pasture>peer mixed pasture in shrub land>single sowing L. davurica pasture. With the increasing of soil depth, underground biomass and soil available nutrient content showed a decreasing trend. The underground biomass in each 0-40 cm soil layer in single sowing of L. davurica was the least. The content of available N and K was the least in peer mixed pasture, and the content of available P was the least in peer mixed pasture in shrub land, indicate that mixed sowing is not conducive to the accumulation of soil nutrients.
To explore the regular patern of soil nutrients season dynamics on the salinealkaline grassland in Songnen Plain, the study was conducted on the alfalfa (Medicago sativa) and Leymus chinensis pasture. The results showed that: There were differences in the variation rules of soil total nitrogen content of the two grassland types were different, but the soil available nitrogen content had the similar variation rules between the two pasture types; In the plant growth season, on the 0-30 cm layer, the soil total nitrogen content had significant differences among three grasslands (P fencing grassland > alfalfa pasture (0.184%). On the 0-30 cm layer, the soil available nitrogen content were sored L. chinensis pasture > fencing grassland > alfalfa pasture. Furthermore, the fall soil total nitrogen content and soil available nitrogen content were sored alfalfa pasture > fencing grassland > L. chinensis pasture on the 0-30 cm layer. The content of soil organic matter of alfalfa pasture and L. chinensis pasture also showed decreasingincreasingdecreasing trend.
Antifungal activities of the alkaloid extraction from endophyte-infected (E+) and endophyte-free (E-) Achnatherum inebrians were tested against Claviceps purpurea, Drechslera erythrospila, Fusarium avenaceum, Bipolaris sorokiniana, Curvularia lunata, F. semitectum, F. solani and Alternaria alternata to definite the bacteriostatic activity of drunken horse grass (Achnatherum inebrians)alkaloid extract. The results of HPLC analysis found that ergot alkaloids, ergonovine and ergine were existed in the E+ drunken horse grass. The concentrations were 26.178 and 369.074 mg·kg-1, but these two alkaloids were not detected in the E- extraction. The alkaloid extraction from E+ and E- drunken horse grass inhibited the colony growth and spore germination of the 8 fungi differently, extraction from E+ had stronger inhibition to tested fungi than E-. The inhibition rate of E+ alkaloid extraction to the colony growth and spore germination of F. avenaceum was the highest with 63% and 57%, respectively. The concentration of alkaloid extraction and the spore germination inhibition rate of tested fungi was significantly positive correlation (P<0.05). Fungi of grass endophyte infection increased the antifungal activity of drunken horse grass extraction.The symbionts contained alkaloids ingredients, however .the specific chemical substances of the extractions and the mechanism of antifungal activity need further research.
Phosphate dissolving bacteria had been isolated from rhizosphere of 7 kinds of grasses based on PKO and Mehknha culture media. The results showed that there were different colony characteristics in growth rate, color, shape, edge integrity, as well as the surface condition of the ridge in different bacteria strains. The number of inorganic phosphate solubilizing strains from rhizosphere of Achnatherum inebrians showed that soil adhering to roots＞rhizoplan or surface of roots＞histoplan or interior of roots, strains from others grasses were rhizoplan or surface of roots＞soil adhering to roots＞histoplan or interior of roots distribution trend. In the first 10 days, most of the dissolved inorganic phosphorus strain’s D/d stabilized, but most of the dissolved organic phosphorus strain stabilized in the first 14 d. Phosphorus solubilizing capability of the strains were determined by the molybdenum blue spectrophotometry, the results indicated that there were lager differences in 109 phosphatedissolving microorganisms capability, phosphate concentration was between 0.47～582.46 μg·mL-1, of which strain PCRP5 had the highest phosphate solubilization capacity. For the 143 strains organic phosphate dissolving bacteria, the ability to dissolve organic phosphorus was large (concentration was 0.07～14.76 μg·mL-1), the highest P concentrations was strains MCMRS4. There were no obvious relationship between the organic phosphorus strains solubilization capacity and pH (P＞0.05), however pH of PKO showed significant negative relationship with the organic phosphorus strains P concentration (P＜0.01).
On the basis of field quadrat survey, a study was conducted on plant community composition and species diversity by the detailed investigation and statistical analysis in Qingshuigou earthquake landslide of Wudu District, Longnan City, Gansu Province. The results showed that: 1) There were 26 dominant species of herbs which occupied by 76.5% of the natural recovery vegetation in the study area, and there were 8 species of shrubs and no arbor species distribution, and herbs and small shrub plants were dominant in community composition, and the dominant species were Cynodon dactylon, Digitaria sanguinalli, Heteropogon contortus, Phragmites australis, Peganum harmala, etc. 2) There were different in the composition of community species, community types and community structure of plants among various sites due to environmental factors; 3) It was especially different in the environmental factors of the hydrothermal and illumination combination at different sites, which caused the natural restoration ability of plant community exist obvious difference. It was that middle slope position>down slope position>up slope position in the sequences of natural restoration ability and antiinterference ability index.
Chaiwopu Lake is an important water sources and ecological barrier of Urumqi, which located in Dabancheng District of Urumqi. Recently years, due to the natural factors and the actions of human being, a series of ecological and environmental problems have been caused. Through field investigation, the composition of vascular plants, the floral geographical elements, lifeform, ecotype and the characteristic of plant community of Chaiwopu Lake wetland have been analyzed. The results showed that there are 30 families,84 genera, 122 species of vascular plants in Chaiwopu Lake wetland, including 1 pteridophyte, and 90 species in 62 genera and 23 families of dicotyledonous plant, and 31 species in 21 genera and 6 families of monocotyledonous plant. The composition of Chaiwopu Lake wetland flora of spermatophytes is simple and with typical temperate characteristic. The vegetation types of Chaiwopu Lake wetland include 20 formations. Referring the life form in Chaiwopu Lake wetland, herbage plant was main, which account for 94.2%. In all ecotype of water plant, mesophyte plants were main with 42 species, accounting for 34.4%. There are 20 plant formation in Chaiwopu Lake wetland. Form. Hordeum bogdanii, Form. Salix rosmarinifolia, Form. Phragmites australis are mainly distributed in north bank, and Form. Halostachys caspica, Form. Galatella biflora, Form. Salicornia europaea are mainly distributed in west bank, and Form. Tamarix ramosissima are only formation in east and south bank.
Eco-environment has been disturbed severely in the Yellow River source by global climatic change and human activity. Currently, it had been gotten people’s close concern on impact of climate change on eco-environment in source region of Yellow River. Based on the analysis and systematic summary of the research results at home and abroad in recent years, authors concluded the climate change characteristics and key problem of the eco-environmental, and gave a comprehensive analysis of the main problems from runoff, soil erosion, wetlands, permafrost and vegetation in the Yellow River source, and discussed the characters of the effect of climatic change on eco-environment. Above all, authors had provided the main strategy of the eco-environment protection in the Yellow River source. The results were as follows: The precipitation was slightly increased, but the temperature was significantly increased in the Yellow River source region; It was great variation that the inter-annual variation and inter-decadal variation for runoff in the Yellow River source region. The runoff was in ample flow period from the middle of 1960s to the late of 1970s and in low water period from the early 1990s to 2008, and the good correlativity was between the annual runoff anomaly and annual precipitation anomaly, and the precipitation intensity was another important cause for runoff volume; The Yellow River source was the region with severe soil erosion, and the wetland was seriously damaged with an obvious decreasing area and dominance and increasing the number of patch, fragmentation degree and fractal dimension; The source region of permafrost had been thinned or disappeared, and there were formed inconsistently frozen ground and residual thawed layers in the vertical profile in the fringe, and raised 50~70 m in the lower limit of permafrost distribution; In general the vegetation cover was preserved previous condition or partially degraded in the Yellow River source. Therefore, we should consummate ecological compensation mechanism, strengthen the construction of a legal system and social environmental awareness, improve the quality of the law enforcement contingent, strengthen the joint of different departments, implement the ecological immigration, and advocate improving the ecotourism to protect the ecological environment of the Yellow River source.
Caragana microphylla is the most dominant and constructive shrub species. We evaluated the level of genetic variation within and among populations sampled from two different altitude gradients using intersimple sequence repeat polymorphism (ISSR) molecular markers. The results showed that eight ISSR primers generated 142 bands, of which 126 (88.73%) were polymorphic. Based on Neis Gst value calculated by POPGENE, the gene diversity (h) and Shannons information index (I) was 0.292 9 and 0.441 7, respectively indicating considerable genetic variations at the species level. At the altitude gradients, the genetic diversity index in populations from low altitude region was higher than from high altitude region, shows that the gene exchange between populations was blocked by the increase of altitude.
To explore the adaptation mechanisms of Fagopyrum dibotrys to high temperature stress and to evaluate the differences of heat resistance of eight F. dibotrys germplasm resources, it was measured that the characteristics of gas exchange and chlorophyll fluorescence parameters in leaves of eight germplasm resources under the high temperature (35 ℃ and 45 ℃) stress. The results showed that: There were very obvious effects of heat stress on photosynthesis and chlorophyll fluorescence parameters; With the strength of the heat stress, it was significantly decreased that the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), water use efficiency (WUE), PSⅡ potential activity(Fv/Fo), PSⅡ maximum photochemical efficiency (Fv/Fm), PSⅡ actual photochemical quantum yield (yield) and PSⅡ photochemical fluorescence quenching (qP) in all of germplasm resources; However, it was increased that the nonphotochemical fluorescence quenching (NPQ) in leave of JQ4, JQ5, JQ7, but decreased as the strength of heat stress was increased, and steadily increased that the non-photochemical fluorescence quenching (NPQ) in leave of JQ1, JQ2, JQ3, JQ6, JQ8. The nine single indexes were changed into two comprehensive indexes by using the principal components analysis. The weight of two comprehensive indexes were 0.816 and 0.184, respectively. According to the results of subordinate function value analysis, the heat resistance capability was in the order of JQ6＞JQ2＞JQ3＞JQ1＞JQ8＞JQ4＞JQ5＞JQ7 in eight F. dibotrys materials. Based on above, the better heat-tolerant F. dibotrys germplasm resourses could regulate the stomatal conductance, decrease the transpiration rate, increase the water use efficiency, and made excited energy dissipated as thermal dissipation to resist high temperature and protect the photosynthetic apparatus.
This study was conducted in the greenhouse with perennial ryegrass (Lolium perenne) varieties Premier and Panterra, which are largerly planted in semiarid areas. The experiment with controlled soil water contents was conducted to study the effects of five treatments repeated drying and rewatering on photosynthetic characteristics. The results indicated that variation tendency of two varieties of perennial ryegrass on photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs)and photochemistry activity of PSⅡ (Fv/Fm) decreased with RSWC decreasing. The activities of photosynthetic parameters in different relative soil water content had different variation trends and also had different recovery level after rehydration. When the relative soil water content was the lower irrigation limit which is 50% RSWC caused stress effect to grasses, it will not cause greater harm. While the treatment which lower irrigation limit was 40% RSWC, two varieties of Perennial ryegrass injury were more and more serious. Both of the two grasses at the end of the drought stage showed severe stress (lower irrigation limit of 20% RSWC) injury, and can not recovered rapidly in the physiological function after rehydration. The comparative result between the two grasses: Premier has the better drought resistance than Panterra. These are suggested that Regulated irrigation on Perennial ryegrass has obvious for RSWC, and showed different result between the two grasses: Premier is 40% RSWC; Panterra is 50% RSWC.
The physiological response of Medicago sativa to cadmium stress and accumulation property were studied with pot experiment.The results showed that the growth of M. sativa was promoted when the concentration of Cd less than 25 mg·kg-1. With the increased concentration of Cd in the medium, relative conductivity chlorophyll contents all decreased, proline contents increased first, then decreased, and reached the highest at Cd level of 25 mg·kg-1. The distribution of Cd in M. sativa was root＞shoot. With the increased concentration of Cd in the medium, Cd content in shoot and root increased, translocation factor and tolerance factor increased first,then decreased. When the concentration of Cd were 25 and 100 mg·kg-1, the Cd content were reached the highest in shoot and root which were 42.5 and 26.11 μg per pot， respectively. It could be concluded that M. sativa was suitable for remediation of Cd polluted soil when Cd concentration was less than 25 mg·kg-1.
Viola tuberifera, which endemic to Qinghai-Tibetan Plateau and its neighbor region, is a typical dimorphic cleistogamous plant. V. tuberifera conducts sexual propagation via both open, chasmogamous (CH) flowers and closed, obligate self-pollinating aerial and subterranean cleistogamous (CL) flowers. In present research, V. tuberifera in alpine meadow of Qilian Mountain within different altitude gradients during cleistogamous full-blossom period was chosen to investigate characteristics of reproductive allocations for understanding behavior of balancing propagation resource to adapt alpine environment. The results showed that: 1) Trade-offs existed not only in vegetation and reproduction，but also in aerial and subterranean cleistogamous flowers sexual reproduction, and probably in sexual and asexual reproduction; 2) Sexual reproductive allocation was sizedependent, and it was negative power exponent correlation between size and sexual reproductive allocation; 3) With the increase of altitude, it was declined drastically that individual size, total sexual reproductive allocation, and also descend in reproductive allocation of aerial cleistogamous flowers, while had a slightly elevated tendency in reproductive allocation of subterranean cleistogamous flowers and bulbs. Furthermore, the reproductive strategies were also changed with altitudes. In the low altitude(2 800 m), plants chose aerial cleistogamous flowers as major strategy, by contrast, preferring to subterranean cleistogamous flowers and bulbs in the high altitude. In a conclusion, the V. tuberifera may regulate reproductive allocations of aerial and subterranean flowers to gain maximum propagation success, adapting changes in high elevation and cold environment, ensuring survival and thrive of species in the alpine meadow ecosystem.
In order to understand the salt-resistance of 33 Elytrigria repens accessions in the period of seed germination, the germination rate, germination index, the length of plumule and radical and seedling weight were measured under 0,0.4%,0.8% and 1.2% NaCl condition and the evaluation was done by membership function method. The results showed that with the increasing of salt concentration, the germination rate, the germination index，the length of radical and plumule decreased, and the change of seedling weight had no rule. By analysis on indexes variance of different concentration among 33 materials, 1.2%NaCl was appropriate concentration for evaluation on salt-resistance in the period of seed germination of E. repens. According to the comprehensive evaluation of salt-tolerance, E04, E08, E23, E11 and E25 had high salt-resistance, and E27, E35, E37, E38 had low salt-resistance.
Present study investigated the effects of different soaking time with 98%H2SO4, different concentrations of NaOH and KNO3 solution on seed germination and seedling growth of Aeluropus littoralis. The results showed that both germination rate and seedling length of A. littoralis were significantly promoted by immersion in three chemical reagents. The effects were better, when putting seeds in 98%H2SO4 solution for 5 min, 10% NaOH solution for 30 min and 0.2% KNO3 solution for 24 h, with seed germination of 13.3%, 42.2% and 20.0%, and seedling length of 0.79 cm, 1.97 cm and 1.13 cm, respectively. It was concluded that the best treatment for the germination of A. littoralis was immersion in 10% NaOH solution.
A reseeding study was carried out on the Tianzhu degraded grassland from 2007 to 2009 to explore the effects of reseeding on species richness and aboveground biomass. The results showed that: After reseeding, the species richness increased in 2007, but decreased after 2007; It was increased that the vegetation height, coverage and aboveground biomass, and more, there was especially significance about the aboveground biomass of grass. Therefore, according to comprehensive evaluation based on vegetation height, coverage species richness and biomass, it was more efficient to recover degraded grassland reseeding with Elymus nutans+Bromus inermis+Festuca sinensis, and this method should be used in recovering alpine degraded grassland in Tianzhu county.
Dispersal is one of the fundamental behavior of animal life history and affects the survival, reproduction, growth of individuals as well as the population dynamics, distribution, and genetic structure. With the development of molecular biology, the molecular marker technologies have become a useful tool to study the dispersal of subterranean rodents. The paper summarized the research progress of subterranean rodents’ dispersal, involving microsatellites markers, DNA fingerprinting, mitochondrial D-loop sequences. Meanwhile, we also prospect the dispersal study of plateau zokor using microsatellite technique.
To investigate the impact of planting density, base fertilizer and top dressing on yield and in situ digestibility of Hemarthria compressa, an orthogonal experimental design L9（34）was used to study the grass yield, screenning the optimal combination, and determine the chemical composition and degradability in the rumen of goat. The results showed that under appropriate irrigation and management conditions, planting density of 40 cm×30 cm, manure 54 kg·18 m-2 + compound fertilizer 2.7 kg·18 m-2 base fertilizer, manure 18 kg·18 m-2+ urea 0.16 kg·18 m-2after each mowing dressing, the annual grass yield is the highest, reaching 129.47 t·ha-1. Nutrients of grass harvested by three cuttings were analyed. The CP, NDF and ADF of the fist cutting grass were 12.04%, 62.95% and 48.42%, respectively. The CP content of the first cutting was higher than that of the second cutting (P>0.05) , and that of the third cutting(20.04%, P0.05), and that of the third cutting(7.66%, P0.05), and that of the third cutting (6.18%, P0.05) and the third cutting; the first cutting ED values of OM was 45.10%, higher than that of the second cutting (P>0.05)and that of the third cutting (P>0.05). Thus, the nutrition and ruminal degradation rate of the first cutting H. compressa are better than the other cuttings, it can be used in goat feed.
This study uses Gansu, Qinhai, Xinjiang Province as an example, building the EKC model and using the time series data to analyse the relationship between economic development and grassland degradation in northwest pastoral area in the last 30 years. The result indicated that the relationship between economic development and grassland degradation in northwest pastoral area accord with the EKC model. The inflection point of grassland resources degradation rate of Gansu, Qinghai, Xinjiang are on the 7 777.0 CNY, 21 752.6 CNY and 13 973.6 CNY of percapita income based on the forecast model. Grassland degradation rate in Gansu Province have passed turning point and tend to increase with the development of the economic. The degradation rate of Qinhai Province near the inflection points of the curve. The degradation rate of Xinjiang Province tend to decrase with the economic development. Comparing the prediction results with the primary industry output value of three provinces, Chinese government should formulate a valid policy that adapt to the special culture and geographic feature in Northwest China to relieve the economic pressure on grassland resources, which to balance development between economy and grassland resources.
In present study, the author described and analyzed defects of effective system design that the missing of ecological system value, the spaces of rights virtual subject, and property defects of the Rights vested in the system of grassland by the environmental justice theory as a starting point. And then, author showed that the effective system design should host the values of environmental justice. Moreover, based on the above concept, it should be reformed that property rights system, and improved that the grassland contractual management rights system to achieve effectively sustainable development of grassland ecological civilization.
The experiment was conducted to determine the relationship between soil organic carbon distribution and soil properties among three woodlands at Ice Valley in the upper reaches of Heihe basin, Qilian County of Qinghai Province. This study showed that the average organic carbon density at 0-60 cm layer was sorted as coniferous forest＞forest thicket＞broad-leaved forest. The organic carbon density was 7.18 kg·m-2 in coniferous forest, and was 1.24 times of shrubbery and 1.58 times of broadleaved forest. The soil organic carbon density at 0-10 cm layer was 13.22, 9.49 and 8.62 kg·m-2 in coniferous forest, forest thicket and broadleaved forest, respectively, and was 1.84, 1.63, and 1.89 times of organic carbon density of total soil profile, respectively. The moisture content, aggregate and total nitrogen at 0-60 cm layer was sorted as following order, coniferous forest＞forest thicket＞broadleaved forest, while bulk density, physical grains of sand and pH value was coniferous forest＜forest thicket＜broadleaved forest. The correlation analysis showed that the soil organic carbon content was positively related to natural moisture content, aggregate, and total nitrogen (P<0.05), however, it was negatively related to bulk density, physical grains of sand and pH in three woodlands (P<0.05).