This paper aims to compare the property difference of spatial and temporal distribution of different nitrogen use efficiency maize genotypes and discuss the physiological mechanism of nitrogen efficiency of maize. In this study, phenotype of root crowns of maize in seedling stage (V5), bell stage (V12) and silking stage (R1) was conducted to discover phenes and phene modules related to N acquisition. An image was captured for the whole roots. Custom software was used to measure root phenes including root area, root projected structure length, maximum width of roots, and root angle. The study was conducted to examine the differences in spatial and temporal distribution of maize root at two nitrogen levels (0 and 240 kg hm-2), high efficiency genotype ZHENGDAN958 (ZD958) and low efficiency genotype DANYU13 (DY13) are used in field production. Under the low nitrogen stress conditions, the root area of ZD958 significantly increased after bell stage and exceeds the CK by 20.2% at silking stage. With LN, the root projected structure length of ZD958 was longer than that of CK by 49.4% at silking stage. The low efficiency genotype DY13 had no obvious change at two nitrogen levels. The number of the grain yield and root system biomass of high efficiency genotype ZD958 was remarkably larger than that of low efficiency genotype DY13. During the whole growth stage, the root dry weight, root area and the root width med of high efficiency genotype ZD958 were larger than that of high efficiency genotype DY13. Besides, under the low nitrogen stress conditions, the width of ZD958 deep soil root tended to become longer which is good for the nitrogen absorption from the deep soil. High efficiency genotype can construct a root system which is in a well-developed and reasonable spatial distribution before blooming, so as to ensure plant nitrogen absorption and biomass generation as well. The root index of the nitrogen responsivity of high efficiency genotype ZD958 was higher than that of low efficiency genotype DY13 before blooming.
The current work was carried out in Upper Tanawal which lies in the mid of Western part of lesser Himalaya. The area lies between 34°0.34.40′ N to 34°0.48.88′ N latitude and 72°0.84.27′ E to 73°0.10.50′ E longitude. Upper Tanawal is rich in biodiversity. No work regarding forest and forest situation is done previously in this area. (Farooq, et al., 2017). The area was once housing notable and thick forest strands famous for their habitat uniqueness to harbor number of pheasant and other wildlife species. Due to security reasons and worse situation of law and order compromising government writ the area remained scientifically as well departmentally neglected resulting rapid and vigorous ruthless deforestation. The area was extensively visited and sampled using Quadrate method for phytosociological data collection. Phytosociological attributes like density, cover, and frequency were also Calculated and recorded for all tree species of the area in each quadrat. Altitude, slope angle, atmospheric humidity and temperature were also considered as environmental variables for each sampling site. Results reflect that Upper Tanawal hosts 52 different tree species of 39 genera belonging to 25 tree families. The important forests of Upper Tanawal are under high anthropogenic and environmental disturbances. Some of them may easily be managed because of the presence of large number of seedling; however, some areas need serious attention. It was observed that and are the potential tree species for reforestation and afforestation in the area. This study will be the baseline for new researchers in the study area.
The present study has reported the influence of forest types, altitude and NDVI (normalized differential vegetation index) on the soil properties. The study area covered four districts viz., Hamirpur, Bilaspur, Sirmaur and Solan of Himachal Pradesh state of India. To carry out this study, five forest types at three different altitudes (600–900 m); (900–1200 m) and (1200–1500 m) above sea level having NDVI values of N1 (0.0–0.1), N2 (0.1–0.2), N3 (0.2–0.3), N4 (0.3–0.4) and N4 (0.4–0.5) were taken into consideration. Among the forest types, northern mixed dry deciduous forest was largest reservoirs of soil organic carbon (SOC) (4.46, 1.52 and 1.46% in humus, 0–20 and 21–40 cm soil layers respectively). The lowest values for SOC were found in dry shiwalik sal forests (2.60, 0.79 and 0.62% in humus, 0–20 and 21–40 cm soil layers respectively). The values of SOC decreased with increase in soil depth. The results showed a positive correlation between SOC, available N, P, K, Ca, S with the altitude and NDVI. However a negative correlation between altitude and NDVI was observed with the bulk density, available Mg and soil pH. Soil pH had a negative influence on SOC whereas SOC had a positive influence on the availability of Nitrogen (N), Sulphur (S) and Potassium (K). The availability of competing cations like Potassium (K) and Calcium (Ca) had a negative effect on the availability of less competitive cations like Magnesium (Mg). The results of the present study can be pivotal in future climate change studies, soil carbon stock assessment and land use planning along the lines of REDD+ initiatives in North Western Himalayan ecosystem.
The purpose of this study was to evaluate the allelopathic effect of weeds ( , and ) on germination, growth, dry biomass and chlorophyll concentration of three cultivars of wheat (Ata Habib, Pirsabaq and Serin). In germination test, different concentrations of aqueous extracts (5, 10 and 15 g/l) of the three weeds significantly reduced percent germination; however, 15 g/l extract of resulted in complete failure of germination of cultivar Pirsabaq. In pot culture, root and shoot length, chlorophyll concentration and seedling dry biomass of the three wheat varieties showed differential responses to different weeds. Aqueous extract at 15 g/l of increased root and shoot length and dry biomass of cultivar Pirsabaq; however, these parameters were significantly retarded in other two wheat cultivars by extract of weeds. Moisture content of the cultivars did not show any response to allelopathic stress of the weeds. In contrast, chlorophyll concentration in Pirsabaq and Serin was significantly increased by aqueous extract of all the weeds but reduced it in cultivar Ata Habib by 50%. In general, Ata Habib was found to be the most sensitive cultivar to the imposed allelopathic stress. The phytotoxic potential of three weeds was found in the order of > > .
Oases are a specific ecosystems which date palm are the mainly crop growing for its fruits and others tree parts. Palm orchards are infested by many pests, including weeds species and exposed within time to the challenging invasive weeds to control. The heavy incidence of weeds negatively affects palm productivity, especially in small plantation and divergent distances, while the established orchards, palm trees shading cause deprives from the process of weeds photosynthesis to be lower competitive. The survey was conducted in El-Bahariya and El-Frafra than Siwa oases of which 375 plots were taken. Vegetative analysis in oases altogether demonstrate 91 weed specimens were encountered of which 18 perennial, 42 were broad leaved, and 30 narrow leaved as well as one parasitic weed species belonging to 22 families, whereas Poaceae is the most plentiful family displayed by 38.5% from all families, occurred in date palm orchards during the study. The geographical differentiation affected coefficient of similarity whereas, it in oases recorded the highest between El-Bahariya and El-Frafra than Siwa and El-Bahariya, while El-Frafra Oasis was the most diverse and richness than the others which have the middle soil properties, fertility, and structure. The correlation analysis of weed flora between both El-Bahariya and El-Frafra was higher and more than El-Bahariya and Siwa oases. Under the unique closed agroenvironment of oases, weeds population dynamics are a stable approximately. Regardless of the diversity of annual weed species, perennials species represent the highest dominant number and the pattern of grown weeds was more dominant than wild desert and some invasive weed species. The control action should be taken of perennial weeds and proactive as well as long term prevention for invasive species.
A field study was conducted to investigate the effects of gap disturbance on the seedling establishment process of two native species. Seeds of and were reseeded to artificially created gaps in a degraded steppe in North China. There were seven treatments: shoot gaps and root gaps (10 cm, 20 cm and 40 cm in diameters), no gaps (control). Shoot gaps were formed by removing above ground vegetation and below ground biomass without restricting the re-growth of neighbor roots back into the gap. The root gaps were accomplished by using polyvinyl chloride pipes sunk in the soil of shoot gaps to exclude neighboring roots. Seedling emergence, survival and growth performance after 90 days of growing were recorded for both species. Gap significantly increased soil moisture, especially for root gaps. Emergence increased significantly for both species as gap size increased. Seedling emergence and survivorship of both species were greater in gaps than in controls. However, the gap size showed a significantly negative effect on 's survivorship. Growth performance of and differ in their response to gap disturbance. Gap had positive effects on seedling growth (including seedling height, dry weight, and numbers of tillers and leaves) of , but had negative effects on seedling growth of The two species have significantly different responses to gap disturbance. All results suggest that is a gap-enhanced species, and is not. Predation by insects may be one of the key reasons to explain the stand dominance in this grassland.
Amino acid mineralization and its fate in soil have effects on soil nitrogen cycling. Here we used N-labeled alanine and methionine to study differences in their mineralization from soil organic nitrogen under 60% WHC (water holding capacity) and 90% WHC soil conditions. We found that the maximum mineralization rates were at the 24th hours for alanine and at the 5th hours for methionine, and about two times greater rates at 60% WHC than at 90% WHC. The half-live was 24–72 h for alanine and > 72 h for methionine. Half-lives of amino acids occurred sooner under 90% WHC than under 60% WHC. The results suggested that some kind of amino acids do lead the nitrogen cycling in a specific ecosystem or as a sign to trigger soil nitrogen cycling when land utilization was altered or disturbed severely by humans.
Water scarcity is the primary cause of land deterioration, so finding new available water resources is crucial to ecological restoration. We investigated a hyper-arid Gobi location in the Dunhuang Mogao Grottoes in this work wherein the burial depth of phreatic water is over 200 m. An air-conditioner was used in a closed greenhouse to condense and measure the yearly amount of phreatic evaporation (PE) from 2010 to 2015. The results shown that the annual quantity of PE is 4.52 mm, and that the PE has sinusoidal characteristics. The average PE is 0.0183 mm d from March to November. Accordingly, by monitoring the annual changes in soil-air temperature and humidity to a depth of 5.0 m, we analyzed the water migration mechanism in the heterothermozone (subsurface zone of variable temperature). The results show that, from March to November, the temperature and absolute humidity (AH) increase. This is due to the flow of solar heat entering the soil — the soil subsequently releases moisture and the soil is in a state of increasing AH so that evaporation occurs. From November to March, the temperature decreases. Now, the soil absorbs water vapor and AH is in a state of decline. Thus, it is temperature alternation in the heterothermozone — due to solar heat transfer — that provides the main driving power for PE. When it drives water vapor to move downwards in the heterothermozone, a small part is reversed upwards and evaporates. Solar radiation intensity dominates the annual sinusoidal PE characteristics.
and are widely planted in North China. The needles of and were sampled in the urban, suburban, and rural districts of Tianjin where the atmospheric conditions are significantly different according to the environmental monitoring results. The Cu, Mn, Zn, and Pb concentrations in the samples were examined via ICP. The resistance indexes, and the malonic aldehyde (MDA), soluble sugar, and free proline levels were also determined. The Pearson coefficients between the resistance indexes and the heavy metal contents were analyzed to compare the two plants abilities to accumulate heavy metal and their resistance characteristics. The results indicated that the heavy metal concentrations had the following significant trend: urban areas > suburban areas > rural areas. In urban areas, the Mn, Zn, and Pb concentrations in were as high as 2024.77 mg·kg , 2397.07 mg·kg , and 130.07 mg·kg , significantly higher than in . The Mn, Zn, and Pb concentrations in were extremely significantly positively correlated ( < 0.01), but no significant correlations were noted in . The MDA, soluble sugar, and free proline concentrations in increased as the heavy metal contents rose along the urban–rural gradient, and were positively correlated with the plant heavy metal contents. They were much higher than the contents in where no differences were noted among the sampling sites. In conclusion, the heavy metal resistance methods used by and are different. could absorb and accumulate many heavy metals, mainly through increased physiological resistance to stress. In contrast, resistance relied on avoiding contact with the metals and by reducing absorption. These differences are associated with the biological characteristics of and , and are closely connected with their coniferous and morphological differences.
Floristic inventory of wild plants comprised of total 129 plant species belonging to 42 families and 101 genera. Location wise UAP contributed greater amount of plant species (53%), followed by PFI (29%), UoP (15%) and Islamia College (3%). Majority of the plants were annual herbs (58%), followed by perennial herbs (29%), trees (10%) and shrubs (3%), respectively. The leading families included Poaceae, contributed 18% of all the plant species. Habitat wise, 44% of them grew in grassy plains, abandoned lands and mismanaged lawns, followed by roadsides (34%), undulating grassy plains (15%) and stony grounds with uneven topography along with stream banks and drainage ditches (7%). Still some of plant species were used as ornamentals, while some shrubs were use in fencing around fields; others were utilized as green manure, for fishing, sheltering and religious purposes. Exploring and identifying the wild flora of the campus and compiling as a handbook would help to monitor new plants introductions particularly of noxious invasive weeds in the campuses in future.
The present study investigates the variation in the relative growth, biomass and nutrient allocation in two threatened tree species . Hook.f. & Th. and Wall. ex Müll. Berol. grown under three different levels of irradiance. The irradiance ranged between 1 and 12 mol m d . Results showed that the highest relative growth rate (RGR) was achieved under the intermediate light treatment for both the species (mean: 0.005 mg mg d ). The growth response coefficient (GRC) model revealed that net assimilation rate (NAR) was the factor driving the RGR in both species. A significant positive correlation was found between NAR and RGR (R = 0.33, = 0.000) whereas specific leaf area (SLA) and leaf mass fraction (LMF) was negatively correlated to RGR. Overall, multiple regression of the studied species based on the independent variables . NAR, SLA, and LMF showed a significant relation with RGR (F(3,50,53 = 13.001, = 0.000, R = 0.43). The biomass distribution in the studied species is in agreement with the “balanced-growth hypothesis” where high irradiance increased allocation to below ground biomass fraction and decreased irradiance increased allocation to the above ground fraction. The highest nitrogen concentration in leaves was observed under the intermediate light treatment. Overall seedlings growth under intermediate light had a higher mean RGR indicating the species' preference for partial light conditions. Long-term experiments under varied light conditions as in the present study would provide useful insight into plant growth strategies in varied environmental conditions.
The random disposal of vegetable residues in north China has become an important obstacle for the sustainable development of vegetable industry. The composting treatment technology has been transformed into organic fertilizer by high temperature fermentation, which has become a widely promoted agricultural clean production technology. However, due to the voluntary nature of farmers' adoption and their reluctance to adopt, this study aimed at assessing the factors that influence their adoption will and evaluate the value of willingness to pay (WTP) for composting technology. Data were collected from 142 respondents through a household survey in Gaocheng District by using structural questionnaire of contingent valuation method (CVM). Some qualitative response models (Probit, Logistic and multiple linear regression models) were applied for examining the main factors influencing the vegetable residue compost adoption and estimating the WTP value. The findings showed that social resource factors play an important role in the respondents' behaviors toward composting technology adoption. The empirical results indeed highlighted that subsidy policy, top dressing time, age, scale, investment of irrigation and net income have significant positive influences on the WTP of compost, while work time and information sources have a negative impact. Government subsidy is a necessary premise for implementing the composting program. The governments should subsidize the remaining 97% of the construction costs to ensure the smooth implementation of composting technology. The findings specifically mentioned that the subsidy object should be the disadvantaged peasant groups with lower household income but more environmentally conscious. This paper is believed to not only assess the technical externality of vegetable residues for the first time but also provide decision reference for policymakers, especially in the background of rapid development of agricultural clean production technology, the accuracy and efficiency of subsidies should be improved.
In this study the effects of environmental factors on some vegetative characteristics of was investigated in Kouh gachan, Ilam, West of Iran, using multivariate analysis. Therefore 64 sample plots with a size of 200 m were considered for measuring the vegetative parameters. Some environmental factors such as slope, aspect and soil depth were recorded in all sample plots. The Detrended Correspondence Analysis (DCA) was used to investigate the relation between vegetative parameters and environmental factors. Redundancy analysis (RDA) analysis was also used to interpret the results. The results of DCA analysis showed that the effect of environmental factors on vegetation cover is significant. Slope had the smallest and the soil depth had the biggest effect on vegetative characteristics of . The results also confirmed the usage of RDA analysis for investigating the relationship between environmental factors and vegetative characteristics.
There are high numbers of endangered birds in Iran. Birds also are indicators of biodiversity in different landscapes and using birds as indicator give us a complete overview about the ecological status of the landscape. In the present study migratory waterfowls were used to identify biodiversity hotspots in Iran. Iran is an interesting place for ornithologists because it is in fact a crossroads of flyways for migratory waterfowls coming from Europe, southern Asia, and Siberia. We predicted the habitat distributions for 27 bird species of Anseriformes in Iran using an ensemble forecasting framework to identify biodiversity hotspots. Moreover, we measured the percentage of overlap between hotspots and protected areas including Ramsar sites. The results showed that suitable habitats for different bird species greatly varied among different ecosystems and they showed dissimilar responses to environmental variables. However, for most species digital elevation model (DEM) was the most important variable in predicting suitable habitats. Our study also revealed that 36.02% of Iran can be considered as suitable habitats for the species and the highest suitability belongs to areas along Zagros and Alborz mountain ranges. Furthermore, the suitable habitats had 7.10% overlap with protected areas and 75% with Ramsar sites. The low overlap between hotspots and protected areas demonstrated the shortage of biodiversity protection in Iran. Therefore, it is essential to select new protected areas based on biodiversity hotspots, and to develop a network of protected areas within those hotspots in Iran.
In order to examine germination characters, seedling parameters, water relative content, tolerance index and enzyme activities of seven Hungarian wheat landraces varieties (Tiszadadai, Riscsei, Komloi, Leweucei, Mateteleki, Mikebudai and Nyiradi) under five concentrations of water stress (0, 6, 12, 18, and 24%) of polyethylene glycol (PEG-6000). A laboratory experiment has been conducted through Factorial Experiment in Randomized Complete Block Design (RCBD) with four repetitions at Research Institute of Nyiregyhaza, Hungary. From the obtained results, Leweucei variety was surpassed other studied verities under study and recorded the highest values of all studied characters followed by Mateteleki, Komloi, Nyiradi, Riscsei, Tiszadadai and Mikebudai. Increasing water stress (PEG-6000) from 0 to 6, 12, 18 and 24% significantly reduced germination characters, seedlings parameters, water relative content (WRC), tolerance index and α and β-amylases activities. Generally, under water stress condition, Leweucei and Mateteleki varieties were recorded the highest values of water relative content (WRC), tolerance index (TI) and α and β-amylases activities as well as able to prompt better drought tolerance and could be suggested as a good resource for breeding programs and cultivation under drought stress conditions compared with other wheat landraces varieties.