Display Mode： |
The paper analyzed the relations of precipitation, soil moisture, water consumption and forage yield at different time, and established the corresponding empirical equation by using biomass, soil moisture of natural grasslands and meteorological data of nearly 15 years in 3 stations of Inner Mongolian typical steppe area. The result indicated that correlation of various moisture factor with the yield was soil moisture water consumption precipitation; Influence of moisture on the yield had the tendency of small in earlier growth period and larger in middle and later period, indicating that the relativity increased with the growth of forage, moisture content had accumulative effect on forage yield. In ordinary circumstances, the moisture content of forage yield has been basically provided by 050 cm soil layers. The relations of soil moisture, water consumption and forage yield could be modeled by linear or exponential equation; The relationship between precipitation and forage yield be modeled by seconddegree curve. The conclusions and equations could provide reference to forage yield monitoring, drought evaluation and analyzing.
Based on the data obtained from 10 meteorological stations on Tianshan Mountains during 1961-2006, the fundamental change characteristic of annual average temperatures, annual precipitation were analyzed, and the natural vegetation net primary productivity (NPP) in nearly 46 years of Tianshan Mountains were calculated using the net primary productivity models for natural vegetation made by ZHOU Guangsheng and ZHANG Xinshi. Statistic relations between NPP and annual average temperatures, annual precipitation were constituted, and the effect of future climate on NPP was estimated. The main results showed that in 46 years, annual average temperature increased at 0.029 ℃/a; annual precipitation variations increased at 1.38 mm/a; natural vegetation net primary productivity increased at 0.013 t/（hm2a）. The climate turned to be warmer and humid at the beginning of 1970s and accordingly, natural vegetation net primary productivity had a sudden increase. This kind of climate change in the future will have a positive effect on natural vegetation net primary productivity in Tianshan Mountains. Averagely, if annual average temperature elevates every 1 ℃ or annual precipitation increases every 10%, the NPP will increase 4%-5% if other conditions invariable.
Forestry coverage in China has declined, and vegetation was destroyed severely, especially in diggings. This paper established a math model for vegetation improvement cost in diggings for cost accounting. Coal waste piles in Didao Forest Farm was used as a study case. The vegetation restoration method and cost were demonstrated and math model was used. The cost differed according to different restoration methods. Suggestions were presented in terms of strengthening technical research, increasing investment, developing vegetation restoration pilots, providing reference to national ecocompensation criteria.
Effects of four basic measures, including grazing prohibition, grazing suspending, reseeding, and rotational grazing, on vegetation restoration in five years were investigated since 2003 in semi-arid grassland of 3 experimental counties of restoring grassland from overgrazing project in Jiuquan city. The results showed that in terms of comprehensive effects of plant diversity, coverage, height and production, all of the four measures were significant; among which, grazing prohibition and reseeding had better effects than the others. For ecological restoration on seriously degraded grassland, the best project was prohibiting grazing four to five years continuously. For both ecology restoration and livestock production, the best project was combining grazing prohibition with reseeding. Given priority to grassland construction, the best project was rotational grazing, but should avoid or reduce spring and autumn grazing.
The distribution, cause and harm of rocky desertification in Yunnan province were analyzed in this paper. It was pointed out that the rocky desertification area distributed in every region of Yunnan, the distribution scale and the damage were different among different regions. The distribution area of rocky desertification increased and the degradation aggravated from north to the south; eastern was serious than the western. Strong human activities were the dominant driving force of rocky desertification, which accelerated ecological environment deterioration, including soil and water erosion, river channel sedimentation and frequent natural disasters, leading to soil resources losing, non-zonal drought and so on. The patterns of forest vegetation recovery, grassland animal husbandry, the ecological migration and ecological agricultures of transforming slope mountainous area into terrace, stereo-structural agriculture and livestock raising-biogas-crop planting are summarized, which were applicable for different rocky desertification areas of Yunnan.
Soil seed bank indicates the total amount of survived seeds in the litter of upper strata and in the soil. The theory of soil seed bank is regarded as the basic theory of community ecology and restoration ecology, an important component for natural regeneration in degraded ecosystems, and has become a hot issue in plant ecology. The study of soil seed bank is an important supplement to biodiversity research, helps to understand vegetation regeneration and the dynamic process of vegetation evolution, and is indispensable for vegetation reconstruction, recovery and operation practice. As the potential community, grassland soil seed bank is the base of settling, survival, reproduction and spreading of plant populations, the origin of plants in grassland ecosystem. This paper reviewed the methodology, contents and signification of the studies on grassland soil seed bank, especially in alpine region. The problems and future study on soil seed bank were presented and discussed. In the process of the restoration and reclamation of degraded vegetation, the study on the soil seed bank can provide scientific information and important theory for vegetation regeneration in alpine region.
345 lines of wild soybeans (Glycine soja) were collected from alkaline land in Baicheng of Jilin province. Different alkaline degrees soil was used for stress treatment from seeding. The germination rate and plant height were decreased with the increasing of alkaline concentration. Seed germination and growth were inhibited by 50% at pH 9.0. The 3 weeks seedlings were treated with 0, 50, 75, 150, 300, 500 mmol/L NaHCO3, which indicated that the seedlings grew normally under 0 or 50 mmol/L stress and the others wilted after 19, 6.5, 3, and 0.5 h respectively. 9 lines were selected with high germination rate and seed setting rate in alkaline soil (pH 9.0). Their contents of Chlorophyll, relative electrical conductivity and malondialdehyde were measured. G07048，G07092 and G07256 had no significant difference in the above index after stress treatment and were alkaline tolerant.
The epidermal micromorphology characters of the seven species of Potentilla from Liaoning were examined with the light microscope(LM).The results showed that the cells of both surfaces had sinuate thick anticlinal walls, the combination of epidermal cells were more closely to enhance the resistance and mechanical support ability. The leaf epidermal micromorphology of the seven species of Potentilla could be divided into three types by the epidermal cell shape：1) Polygon: The shape of the upper epidermal cells of P.flagellaris, P.fragarioides, P. discolor and P.paradoxa, P.freyniana were polygonal.2) Nearly polygon: The shape of the upper epidermal cells of P.multicaulis, P.kleiniana and the lower epidermal cells of P.paradoxa were nearly polygonal.3) Irregular: The shape of the lower epidermal cells of P.flagellaris, P.fragarioides,P.discolor, P.multicaulis and P.kleiniana were irregular. There was no stomata on the upper epidermal cells of P.fragarioides, P.discolor, P.paradoxa, P.freynian. There were rarely fewer stomata on the upper epidermal cells of P.flagella. There were stomatas on the upper epidermal cells of P.multicaulis and P.kalinin, and the lower epidermal cells of P.flagella, P.multicaulis, P.Kalinin, P.fragarioides, P.discolor,P.freyniana, P.paradoxa. The stomata index of the lower epidermal cells of P. fragarioides,P. multicaulis and P. discolor were obviously larger than the lower epidermal cells of P.flagellaris,P.paradoxa,P.freyniana and P.kleiniana. The stomata index of P.flagella,P.multicaulis and P.kleiniana on the upper epidermis was smaller than on the lower. The stomata index study showed that P.flagella, P.paradoxa, P.kalinin, P.freyniana had strong drought resistance.
The hightemperature tolerance index of four ground covering plants under different heat stress was studied. Through measuring physiological hightemperature tolerance characteristics such as relative permeability of plasma membrane, content of MDA ,SOD and POD activity, proline, chlorophyll, soluble sugar and soluble protein content; and a comprehensive evaluation on hightemperature tolerance of different species of four ground covering plants was given based on subordinate function values analysis. The results indicated that the order of hightemperature resistance from high to low was : Lyaimachia alfredii and L.christinae var. huayeL.congestiflora and L.nummularia Aurea, this accorded with their practical performance. Fuzzy subordination method could be used to analyze the hightemperature tolerance completely and avoid the shortage of single index.
The protein content of leaf and whole plant of ten different white clover varieties were analyzed at different growth stages. The result showed that the difference of white clover protein contents among varieties or growth stages was significant (P0.01). The seasonal dynamics of protein contents of all varieties exhibited a single peak pattern, and the peak appeared in early flowering stage. Haifa, Hankou and Guizhou wildness ecotype were suitable for Beijing area and the optimal utilization time is early flowering period.
Fermentation qualities and chemical compositions of Medicago sativa and Leymus chinensis were studied by adding three different lactobacillus additives (LD, H/MF and FS). The results showed that L. chinensis could be silaged well without adding any additives. Adding LD, FS and 0.01%H/MF markedly increased the content of lactic acid and decreased the content of butyric acid (P0.05), which meant that its fermentation qualities were improved. As to M. stativa, the pH value and content of butyric acid were increased without adding any additives and could not form good silage. High quality silage of M.stativa can not be obtained either by adding these three additives either. But its fermentation qualities were better than control when adding LD or 0.002 5% FS. In addition, there were no significant (P0.05) effects of NDF and ADF contents on both silages by adding three lactobacillus additives.
he yield of oneyear King grass(Pennisetum purpureumP.typhoideum) showed increasing trend with the increase of mowing height; Fresh and dry yield were the highest at 220 cm mowing height, and fertilizer effect was significant. The ratio of stem and leaf showed significantly linear correlation with mowing height and little effect from fertilizer. The content of CP, EE and Ash was declining with the increasing mowing height, and the content of CP is significantly negative correlated with mowing height. The content of NDF, ADF, ADL and Ca showed increasing trend with the increasing mowing height. Evaluated from yield, nutrition content and digestibility, fertilized oneyear King grass had the highest utilization value at 100 cm mowing height.
Clipping frequency of Sugargraze, a new hybrid variety of sweet sorghum introduced in 2001, was studied. The result showed that with the increasing of clipping times, fresh and dry yield, crude protein reduced, but the unit content increased. Cutting only once had the highest fresh, dry yield and crude protein of 110 780, 29 750, 1 250 kg/hm2, respectively; the treatment of 2 cuttings followed, but with higher stem sugar content; 3 cuttings was the worst and should not be used.
Clipping is one of common ways in using and management of grassland. It can affect the biomass and quality of grazing by two approaches. Firstly, clipping can accelerate the growth speed and enhance the biomass of grazing by using the compensation growth of plant. Secondly, clipping can change the aggradations of nutrition and direction of distribution of grazing by the functional equilibrium of plant, and then affect the quality of grazing. The hackneyed methods of clipping include the frequency of clipping, the time of clipping and the mode of clipping. This paper was expounded the influences and mechanism for the biomass and quality of grazing in order to offer the consult for the suitable clipping.
The experiment studied dynamic change of soil nutrient in free tillage spring wheatgrass intercropping land, and analyzed the effect of wheatsweet clover, wheatwild pea, wheatpea, wheatmaize, wheathairy vetch intercropping on soil organic matter, alkalisoluble N and available P. The result showed that the treatments of wheatgrass intercropping increased soil organic matter, alkalisoluble N and available P. Wheatsweet clover and wheatwild pea intercropping increased alkalisoluble N 4.8 mg/kg(19.4%) and soil organic matter 0.39 g/kg(1.6%)，respectively. Wheatwild pea intercropping also increased 8 mg/kg(23.9%) available P. The contents of soil organic matter, alkalisoluble N and available P reduced with the increasing soil depth.
Gansu grassland rodent flora were composed of 68 species, which accounted for 75.6% of total rodent in Gansu, population density of most species was under economic loss level, and play an important role in grassland ecology system. As many as 1826 species could cause economic loss, and dominated in different types of grassland. The grassland rodent pest division should follow history development, ecological adaptability and production practice. Thereby, the grassland rodent pests of Gansu province were compartmentalized to five regions according to indicators of grassland rodent faunal component, zonal biology climate, zonal vegetation, and thirteen subregions according to indicators of preponderant zonal grassland type, representative rodent distribution and dominant rodent species.
Using PCR product direct sequencing, mitochondrial control region sequences of 18 individuals of three zokors were confirmed and analyzed. Similar to other rodents, the control region of zokor was composed of three domains, the extended termination associated sequence (ETAS) domain, the central conserved domain (CD) and the conserved sequence block (CSB). A series of conserved sequences of zokor and their forms were identified. Using Microtus rossiaemeridionalis, Rattus norvegicus, Mus musculus and Nannospalax ehrenbergi as outgroup, the phylogenetic relationship of zokors was analyzed by neighborjoining (NJ)method and UPGMA method.The result showed that the control region could be used for the phylogenetic analysis. Based on the results of molecular phylogenetic analysis and morphological comparison, it was suggested that M.baileyi and M.cansus reach the species level.
This paper studied growth condition, hydrological and ecological effects of above ground part of wild Pennisetum alopecuroides and Cynodon dactylon. Results showed that wild P.alopecuroides was evidently better than C. dactylon(CK) in stand formation speed, time, height and above ground biomass; the maximum interception rate and amount of wild P.alopecuroides were 45.35% and 5.12 mm, higher than the control; the effective retaining water rate and amount of litter layer of wild P. alopecuroides were 304.88% and 0.19 mm, lower than the control; its stems and leaves coverage could reduce ground temperature and maintain soil water, much more effective than the control.
Many times of mowing experiments on Poa Pratensis L.cv.QinHai showed that rooting speed had no significant difference in two sample areas. No remarkable difference was observed on tillering value among treatments and sample areas. Different treatment affected tillering rate obviously. Low mowing at high frequency (mowing at 5 cm, every 7 days) was helpful for tillering.
The effects of waterretaining agent (WRA) on the growth and physiological metabolism of Sedum sarmentosum were studied through adding WRA to the substrate (vermiculite, peat, coal ash with the same volume). The results showed that the application of WRA promoted the bud germination and elongation and increased the contents of photosynthetic pigments, the leaf relative water content, the free amino acid contents and the root vigor. And the dry matter accumulation was improved as well. It was more significant for increasing the accumulation of dry matter, the growth of aboveground part, the leaf relative water content and the amino acid contents under drought condition. However, the high dosage would reduced the root vigor. The suitable amount of WRA used in the roof turfgrass of Sedum sarmentosum was 1 g/L.