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Analysis of the effect of air temperature on ammonia emission from band application of slurry
2021
Pedersen, Johanna | Nyord, Tavs | Feilberg, Anders | Labouriau, Rodrigo
Field application of liquid animal manure (slurry) is a significant source of ammonia (NH₃) emission to the atmosphere. It is well supported by theory and previous studies that air temperature effects NH₃ flux from field applied slurry. The objectives of this study was to statistically model the response of temperature at the time of application on cumulative NH₃ emission. Data from 19 experiments measured with the same system of dynamic chambers and online measurements were included. A generalized additive model allowing to represent non-linear functional dependences of the emission on the temperature revealed that a positive response of the cumulative NH₃ emission on the temperature at the time of application up to a temperature of approximately 14 °C. Above that, the temperature effect is insignificant. Average temperature over the measuring period was not found to carry any additional information on the cumulative NH₃ emission. The lack of emission response on temperature above a certain point is assumed to be caused by drying out of the slurry and possible crust formation. This effect is hypothesized to create a physical barrier that reduce diffusion of NH₃ to the soil surface, thereby lowering the emission rate. Furthermore, the effect of the interaction between soil type and application technique and the effect of dry matter content of the slurry was derived from the model, and found to be significant on cumulative NH₃ emission predictions.
Mostrar más [+] Menos [-]The impact of SO2 and SO2 + ascorbic acid treatments on growth and partitioning of dry matter in Trigonella foenum-graecum L
1996
Krishnayya, N.S.R. | Date, M.V. (Department of Botany, M.S. University, Baroda 390002 (India))
Acceleration of 13C-labelled photosynthate partitioning from leaves to panicles in rice plants exposed to chronic ozone at the reproductive stage
1995
Nouchi, I. | Ito, O. | Harazono, Y. | Kouchi, H. (National Institute of Agro-Environmental Sciences, 3-1-1 Kannondai, Tsukuba, Ibaraki 305 (Japan))
Vegetative growth of soybean as affected by elevated carbon dioxide and ozone
1995
Reinert, R.A. | Ho, M.C. (USDA-ARS, Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina 27695 (USA))
Geo-Referenceable Model for the Transfer of Radioactive Fallout from Sediments to Plants
2012
Ahamer, Gilbert
In order to quickly assess the transfer of radioactive cesium after a nuclear incident, it is useful to know the main biospheric parameters influencing this transfer. A suitably simplified heuristic formula for the Cs transfer is helpful for further application in a Geographic Information System (GIS). In order to determine the most relevant parameters given their huge variability in nature, samples of 150 aquatic plants and the corresponding sediments of 26 diverse aquatic locations such as lakes, ponds, and disconnected parts of rivers were measured for 137Cs, 134Cs, and 40K radioactivity one year after the nuclear disaster of Chernobyl. Sediments were characterized by determination of weight loss after heating, extractable Cs and K, pH(KCl), particle size distribution, content of clay minerals, and similar biospheric, chemical, and physical parameters. As a general concept, the procedure of uptake of radioactive cesium was subdivided into the two following steps: “resorption of cesium fallout by soil” and “uptake of soil cesium by plants”. Results for the resorption by soil show strong dependence on the percentage of dry matter and on the content of muscovite (mica) in the sediment. The uptake in plants, however, depends mostly on the content of 137Cs in the sediment itself, on the content of montmorillonite (weathered mica) and on the transfer factor of 40K which indicates the potassium affinity of the 30 different collected plant species. These findings can serve to quickly and practically assess the transfer factor across larger geographic regions in an evidence-based manner. Suitable IT tools for such space-related estimations are Geographic Information Systems or Virtual Globes such as Google Earth.
Mostrar más [+] Menos [-]Metal Accumulation and Functional Traits of Maianthemum bifolium (L.) F. W. Schmidt in Acid Beech Forests Differing with Pollution Level
2022
Bierza, Karolina
Maianthemum bifolium (L.) F. W. Schmidt is a clonal plant with a wide geographical range throughout Europe and Asia. It is also abundant as an understory plant of acid beech forests in southern Poland. The response strategies of this species to heavy metals and their effects on some functional traits (height, specific leaf area (SLA), leaf dry matter content (LDMC), specific rhizome length (SRL) and rhizomes dry matter content (RDMC)) were tested. Selected heavy metal concentrations were measured in leaves, rhizomes and rooting soil of May lily in five beech forests of southern Poland, mainly including an industrialised region of Upper Silesia. The contamination level of these ecosystems was assessed with a single pollution index. The results show significant contamination with Pb even at control sites and moderate with Cd, Zn, Fe and Cu in Upper Silesian forests. May lily accumulated Pb, Zn and Fe mainly in rhizomes, but Ni, Cu and Cd were also translocated to aboveground organs in comparable quantities, which confirms the indicator value of this plant. May lily accumulated up to 21 and 30 mg g⁻¹ Cd, 34 and 90 mg g⁻¹ Pb and 250 and 553 mg g⁻¹ Zn in leaves and rhizomes respectively. Moreover, the accumulation factors show that May lily accumulates Cd in above- and underground organs in higher amounts than found in soil. Although high concentrations of these toxic elements in tissues, no visible damages on plants were observed, also the measured functional traits show no apparent relationship with the pollution level.
Mostrar más [+] Menos [-]Estimation model and its trade-off strategy of Mangifera persiciforma Colletotrichum gloeosporioides degree based on leaf reflection spectrum
2021
Zhu, Jiyou | Cao, Yujuan | Yao, Jiangming | He, Weijun | Guo, Xuan | Zhao, Jiajia | Xu, Qing | Zhang, Xinna | Xu, Chengyang
Colletotrichum gloeosporioides is one of the most common and serious fungal diseases of the tree Mangifera persiciforma. Yet we lack an effective method to evaluate this ecological interaction accurately. Here, we measured the functional traits and leaf reflectance spectrum of the host plants under different disease degrees. The findings provide a fast and efficient method for large-scale and high-precision monitoring of C. gloeosporioides in M. persiciforma stands. Using the collected leaf reflection data, we set up a prediction model of the optimal disease degree. Firstly, we found that leaf functional traits of M. persiciforma generally consisted of low leaf thickness, low relative chlorophyll content, small specific leaf area, high leaf tissue density, high dry matter content, low stomatal density, and large stomatal area. Secondly, leaf reflectivity increases with damage of C. gloeosporioides, which corresponds to five main reflection peaks and five absorption valleys in the spectral reflectance curve of leaves at the same positions (350–1800 nm). Thirdly, with the increase of infection degree, red edge slope and yellow edge slope decrease, while green peak reflectance, red valley reflectance, and blue edge slope all increase. Blue shift was detected in the red edge, green peak, and red valley, while red shift appeared at the blue edge and yellow edge. Finally, the best predictive model was that based on green peak reflectance (y=3.6396–0.0693x, R²=0.5149, RMSE [root-mean-square error] =0.2735), with an R²=0.92 and RMSE=0.0042 between its predicted vs. observed values. Because of its high inversion accuracy, the model can be used to predict the invasion conditions of M. persiciforma by C. gloeosporioides. Our study demonstrated that when plants are infected by C. gloeosporioides, there was a strong trade-off relationship between leaf functional traits. On the global leaf economics spectrum, the leaves tended toward the “slow investment-return” end when infected by C. gloeosporioides.
Mostrar más [+] Menos [-]Effects of crown decline on increment in Norway spruce (Picea abies (L.) Karst) in southern Sweden
1989
Bjoerkdahl, G. | Eriksson, H. (Swedish Univ. of Agricultural Sciences, Garpenberg (Sweden). Dep. of Forest Yield Research)
Adaptability of the structure and biomass of Arundinaria spanostachya clonal populations grazing by wild giant pandas
2020
Wang, Qinqin | Zhang, Longyan | Gan, Xiaohong
To understand the defense mechanism of Arundinaria spanostachya clonal populations in response to grazing by giant pandas, dynamic variations in A. spanostachya clonal population structure and biomass allocation in a wild giant panda habitat at the Liziping Nature Reserve were evaluated, as well as whether the clonal populations would be continuously used by the wild giant pandas. The population density of each age-class in the grazed and control plots after grazing (2014a and 2015a) was similar to that before grazing (2013a). The effects of grazing on the size-class and height-class structures were relatively lower. Before and after grazing, the perennial individuals showed the highest total biomass, followed by the biennial and annual individuals, and the maximum dry matter content in each module was found in the culm, followed by the branch and leaf. The dry matter content of A. spanostachya individuals increased as the age class increased, whereas the total water content decreased. The maximum water content allocation in the modules was observed in the culm, and no significant differences were found between the shoot and leaf. Thus, foraging by the wild giant pandas had no impact on the size-class and height-class structures and biomass allocation of A. spanostachya clonal populations, and the clonal populations have established an adaptive mechanism against grazing by giant pandas. After grazing, the A. spanostachya clonal populations showed greater self-adjustment ability to restore the status to that before grazing and, thus, continuously supply food for the giant pandas. Further management intervention of A. spanostachya clonal populations after the foraging of wild giant pandas is not needed, which has implications for understanding the impact of co-evolutionary mechanisms between giant panda and its staple bamboo species.
Mostrar más [+] Menos [-]Barbary sheep tissues as bioindicators of radionuclide and stabile element contamination in Croatia: exposure assessment for consumers
2019
Lazarus, Maja | Gančević, Pavao | Orct, Tatjana | Barišić, Delko | Jerina, Klemen | Šprem, Nikica
Muscle, liver and kidney of 21 Barbary sheep (Ammotragus lervia) from Mosor Mountain, Croatia, were sampled to quantify the activity of caesium and potassium radionuclides and five toxic and ten essential stabile elements in order to establish reference values for this species and to evaluate the potential of Barbary sheep tissues to reflect environmental pollution. We also assessed seasonal diet (botanical composition and dry matter content) of Barbary sheep based on analyses of a rumen content of culled animals. None of the 19 plant species (mostly grasses) identified as part of the Barbary sheep diet is known as a stabile element or radionuclide hyperaccumulator. Measured levels reflected low environmental pollution with arsenic, cadmium, mercury and lead, with levels generally less than those reported for wild herbivorous ungulates. Methodological differences (detection limit of elements in muscle) were shown to hamper interpretation and comparison of the Toxic Contamination Index (TCI) values with those published for other species. There was no homeostasis disturbance of trace elements in Barbary sheep, either due to inadequate intake via food or as an adverse effect due to a high toxic metal(loid) burden. Consumption of the muscle and liver of wild Barbary sheep can be considered safe for the health of adult consumers regarding toxic metal(loid)s and radioactive caesium, though the liver should be avoided as a food item in vulnerable population groups due to the possible adverse effects of cadmium and lead. Otherwise, muscle and liver are a rich source of copper, iron, selenium and zinc for consumers and, as such, can benefit the overall dietary intake of essential elements.
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