Natural revegetation of hydrocarbon-contaminated soil in semi-arid grasslands

2004 ◽  
Vol 82 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Diana Bizecki Robson ◽  
J Diane Knight ◽  
Richard E Farrell ◽  
James J Germida
Keyword(s):  
Functional Groups ◽  
Plant Species ◽  
Contaminated Soils ◽  
Oil Spills ◽  
Abundant Species ◽  
Perennial Grasses ◽  
Soil Conditions ◽  
Nitrogen And Phosphorus ◽  
Litter Cover ◽  
The Impact

One way to identify hydrocarbon-tolerant plant species for reclamation is to sample vegetation at contaminated sites allowed to recover naturally. We compared vegetation and soils of 14 hydrocarbon-contaminated plots in southern Saskatchewan to those of nearby uncontaminated plots to determine the impact on plant communities and soil properties. Contaminated plots had less vegetation and litter cover than uncontaminated plots, and significantly higher soil carbon to nitrogen ratios, pH, and hydrocarbon concentration, and lower nitrogen and phosphorus. Although species richness was not significantly different, Shannon's diversity was lower on contaminated plots. Mean compositional similarity of the plots, measured using Jaccard's index, was only 31%, and cover similarity, measured using Spatz's index, was only 22%. Vegetation composition differences occurred because mycorrhizal, woody and vegetatively reproducing species, and species using birds or unassisted means for seed dispersal were significantly less common on contaminated than uncontaminated plots. Self-pollinated species were significantly more common on contaminated plots. The most abundant species on contaminated soils were the annual forb Kochia scoparia and the native perennial grasses Hordeum jubatum, Distichlis stricta, Agropyron smithii, Agropyron trachycaulum, and Poa canbyi. This research shows that some plant species and functional groups are tolerant of the altered soil conditions at hydrocarbon-contaminated sites.Key words: functional groups, oil spills, phytoremediation, reclamation, succession, vegetation recovery.

scholarly journals Effects of High Impact Grazing on Species Diversity and Plant Functional Groups in Grasslands of Northern Argentina

2018 ◽  
Vol 10 (9) ◽  
pp. 3153
Author(s):  
Ditmar Kurtz ◽  
Marcus Giese ◽  
Folkard Asch ◽  
Saskia Windisch ◽  
María Goldfarb
Keyword(s):  
Species Composition ◽  
Functional Groups ◽  
Plant Species ◽  
High Impact ◽  
Sustainable Land Use ◽  
Plant Functional Groups ◽  
Seasonal Effects ◽  
Plant Species Composition ◽  
Wiener Diversity Index ◽  
The Impact

High impact grazing (HIG) was proposed as a management option to reduce standing dead biomass in Northern Argentinean (Chaco) rangelands. However, the effects of HIG on grassland diversity and shifts in plant functional groups are largely unknown but essential to assess the sustainability of the impact. During a two-year grazing experiment, HIG was applied every month to analyze the seasonal effects on plant species composition and plant functional groups. The results indicate that irrespective of the season in which HIG was applied, the diversity parameters were not negatively affected. Species richness, the Shannon–Wiener diversity index and the Shannon’s equitability index did not differ from the control site within a 12-month period after HIG. While plant functional groups of dicotyledonous and annual species could not benefit from the HIG disturbance, C3-, C4-monocotyledonous and perennials increased their absolute and relative green cover. Our results suggest that HIG, if not applied in shorter frequencies than a year, neither alters diversity nor shifts the plant species composition of the grassland plant community, but instead it promotes previously established rather competitive species. HIG could therefore contribute as an alternative management practice to the sustainable land use intensification of the “Gran Chaco” grassland ecosystem and even counteract the encroachment of “low value” species.

scholarly journals Effects of Wet Oxidation Process on Biochar Surface in Acid and Alkaline Soil Environments

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2362 ◽  
Author(s):  
Qinya Fan ◽  
Liqiang Cui ◽  
Guixiang Quan ◽  
Sanfei Wang ◽  
Jianxiong Sun ◽  
...  
Keyword(s):  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Functional Groups ◽  
Specific Surface Area ◽  
Contaminated Soils ◽  
Soil Conditions ◽  
Acid Oxidation ◽  
Wet Oxidation ◽  
Alkaline Soil

Biochar has been studied for remediation of heavy metal-contaminated soils by many researchers. When in external conditions, biochar in soils ages, which can transform its structural properties and adsorption capacity. This study was conducted with two oxidation processes, HNO3/H2SO4 and NaOH/H2O2, to simulate the effects of biochar in acid and alkaline soil conditions. The results show that the oxygen-containing functional groups increased in aged biochar, which led to improve the ratio of oxygen and carbon (O/C). Nitro functional groups were found in the acid-oxidation treated biochar. Destroyed ditches and scars were observed on the surface of aged biochar and resulted in growth in their specific surface area and porosity. Specific surface area increased by 21.1%, 164.9%, and 63.0% for reed-derived biochar treated with water washing, acid oxidation, and basic oxidation, respectively. Greater peaks in the Fourier Transform Infrared Spectroscopy (FTIR) results were found in C–O and O–H on the surface of field-aged biochar. Meanwhile, mappings of energy-dispersive spectroscopy showed that biochar aged in soil was abundant in minerals such as silicon, iron, aluminum, and magnesium. In summary, biochar subjected to wet oxidation aging had an increased capacity to immobilize Cd compared to unaged biochar, and the adsorption capacity of oxidized biochar increased by 28.4% and 13.15% compared to unaged biochar due to improvements in porosity and an increase in functional groups.

The impact of pasture development and grazing on water-yielding catchments in the Murray - Darling Basin in south-eastern Australia

2003 ◽  
Vol 43 (8) ◽  
pp. 817 ◽  
Author(s):  
W. H. Johnston ◽  
D. L. Garden ◽  
A. Rančić ◽  
T. B. Koen ◽  
K. B. Dassanayake ◽  
...  
Keyword(s):  
Perennial Grasses ◽  
Wagga Wagga ◽  
Deep Drainage ◽  
Nitrogen And Phosphorus ◽  
South Wales ◽  
Murray Darling Basin ◽  
Productivity Gain ◽  
Eastern Australia ◽  
Annual Grasses ◽  
The Impact

Experiments conducted from November 1996 to June 2002 in adjacent small catchments near Wagga Wagga, New South Wales, compared the productivity and hydrology of a heavily fertilised (about 30 kg phosphorus/ha.year) Phalaris aquatica (phalaris) pasture with that of a lightly fertilised (about 14 kg phosphorus/ha every second year) native grassland that contained a mixture of C3 and C4 perennial grasses, dominantly C4 Bothriochloa macra (redgrass).In summer, the native catchment was dominated by C4 perennial grasses while the phalaris catchment was dominated by annual C4 weedy species. During the cooler months, the phalaris pasture contained higher proportions of Vulpia spp., and other less-desirable annual grasses. Throughout the experiment, the native catchment was dominated by redgrass, whereas in the phalaris catchment the persistence of phalaris declined. Redgrass became prominent on the more arid aspects of the phalaris catchment as the experiment progressed.Pasture production in the phalaris catchment was higher in most seasons than the native catchment, which resulted in an overall stocking rate advantage of about 80%. The productivity gain per unit of P input was 0.4 for the phalaris catchment compared with 1 for the native catchment, implying that phosphorus was applied to the phalaris catchment at an excessive rate.During wet periods the native catchment produced substantially more runoff than the phalaris catchment, while in dry times it developed substantially larger soil water deficits. Runoff from the phalaris catchment was higher in suspended and dissolved nitrogen and phosphorus than for the native catchment. Higher runoff from the native catchment combined with its drier soil profile in summer indicated that its deep drainage potential was less than in the phalaris catchment.

scholarly journals Changes of the CO<sub>2</sub> and CH<sub>4</sub> production potential of rewetted fens in the perspective of temporal vegetation shifts

2015 ◽  
Vol 12 (8) ◽  
pp. 2455-2468 ◽  
Author(s):  
D. Zak ◽  
H. Reuter ◽  
J. Augustin ◽  
T. Shatwell ◽  
M. Barth ◽  
...  
Keyword(s):  
Plant Species ◽  
Gas Production ◽  
Shoot Biomass ◽  
Ceratophyllum Demersum ◽  
Level Control ◽  
Nitrogen And Phosphorus ◽  
Vegetation Shifts ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
The Impact

Abstract. Rewetting of long-term drained fens often results in the formation of eutrophic shallow lakes with an average water depth of less than 1 m. This is accompanied by a fast vegetation shift from cultivated grasses via submerged hydrophytes to helophytes. As a result of rapid plant dying and decomposition, these systems are highly dynamic wetlands characterised by a high mobilisation of nutrients and elevated emissions of CO2 and CH4. However, the impact of specific plant species on these phenomena is not clear. Therefore we investigated the CO2 and CH4 production due to the subaqueous decomposition of shoot biomass of five selected plant species which represent different rewetting stages (Phalaris arundinacea, Ceratophyllum demersum, Typha latifolia, Phragmites australis and Carex riparia) during a 154 day mesocosm study. Beside continuous gas flux measurements, we performed bulk chemical analysis of plant tissue, including carbon, nitrogen, phosphorus and plant polymer dynamics. Plant-specific mass losses after 154 days ranged from 25% (P. australis) to 64% (C. demersum). Substantial differences were found for the CH4 production with highest values from decomposing C. demersum (0.4 g CH4 kg−1 dry mass day) that were about 70 times higher than CH4 production from C. riparia. Thus, we found a strong divergence between mass loss of the litter and methane production during decomposition. If C. demersum as a hydrophyte is included in the statistical analysis solely nutrient contents (nitrogen and phosphorus) explain varying greenhouse gas production of the different plant species while lignin and polyphenols demonstrate no significant impact at all. Taking data of annual biomass production as important carbon source for methanogens into account, high CH4 emissions can be expected to last several decades as long as inundated and nutrient-rich conditions prevail. Different restoration measures like water level control, biomass extraction and top soil removal are discussed in the context of mitigation of CH4 emissions from rewetted fens.

Defining functional groups and their vulnerability to the edge effect in a peri-urban forest in Mexico City

2018 ◽  
Vol 45 (4) ◽  
pp. 342-351 ◽  
Author(s):  
GABRIELA SANTIBÁÑEZ-ANDRADE ◽  
CARLOS GRANADOS-PELÁEZ ◽  
ARTURO GARCÍA-ROMERO
Keyword(s):  
Functional Groups ◽  
Plant Species ◽  
Urban Forest ◽  
Environmental Gradients ◽  
Plant Functional Groups ◽  
Edge Zone ◽  
Site Factor ◽  
Canopy Opening ◽  
Litter Cover ◽  
Interior Zone

SUMMARYThe expansion of human settlements and primary-sector activities (agriculture and forestry) has resulted in the fragmentation of forests, but the impacts of this are still poorly understood. We examined the effect of patch size on the presence of plant functional groups along an edge–interior gradient. Plant species were classified based on a two-way indicator species analysis in order to determine their establishment thresholds and vulnerability along the gradient, while detrended correspondence analyses and canonical correspondence analyses were performed to identify environmental gradients related to vegetation distribution. Two groups of plant species were recognized in all patch sizes: one commonly found towards the edge and the other in the interior zone. The incidence of these groups was correlated with environmental factors associated with the edge–interior gradient, mainly with humidity, soil moisture and light (canopy opening and global site factor) in the edge zone and with litter cover, depth of litter, slope and soil and air temperature in the interior zone. Identifying the species’ threshold responses to fragmentation is key, as they provide tools to prevent the potential local extinction of species.

scholarly journals Changes of the CO<sub>2</sub> and CH<sub>4</sub> production potential of rewetted fens in the perspective of temporal vegetation shifts

2014 ◽  
Vol 11 (10) ◽  
pp. 14453-14488 ◽  
Author(s):  
D. Zak ◽  
H. Reuter ◽  
J. Augustin ◽  
T. Shatwell ◽  
M. Barth ◽  
...  
Keyword(s):  
Plant Species ◽  
Typha Latifolia ◽  
Shoot Biomass ◽  
Ceratophyllum Demersum ◽  
Level Control ◽  
Nitrogen And Phosphorus ◽  
Vegetation Shifts ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
The Impact

Abstract. Rewetting of long-term drained fens often results in the formation of eutrophic shallow lakes with an average water depth of less than 1 m. This is accompanied by a fast vegetation shift from cultivated grasses via submerged hydrophytes to helophytes. As a result of rapid plant dying and decomposition, these systems are highly-dynamic wetlands characterised by a high mobilisation of nutrients and elevated emissions of CO2 and CH4. However, the impact of specific plant species on these phenomena is not clear. Therefore we investigated the CO2 and CH4 production due to the subaqueous decomposition of shoot biomass of five selected plant species which represent different rewetting stages (Phalaris arundinacea, Ceratophyllum demersum, Typha latifolia, Phragmites australis, and Carex riparia) during a 154 day mesocosm study. Beside continuous gas flux measurements, we performed bulk chemical analysis of plant tissue, including carbon, nitrogen, phosphorus, and plant polymer dynamics. Plant specific mass losses after 154 days ranged from 25 (P. australis) to 64% (C. demersum). Substantial differences were found for the CH4 production with highest values from decomposing C. demersum (0.4 g CH4 kg−1 dry mass day) that were about 70 times higher than CH4 production from C. riparia. Thus, we found a strong divergence between mass loss of the litter and methane production during decomposition. If C. demersum as a hydrophyte is included in the statistical analysis solely nutrient contents (nitrogen and phosphorus) explain varying GHG production of the different plant species while lignin and polyphenols demonstrate no significant impact at all. Taking data of annual biomass production as important carbon source for methanogens into account, high CH4 emissions can be expected to last several decades as long as inundated and nutrient-rich conditions prevail. Different restoration measures like water level control, biomass extraction and top soil removal are discussed in the context of mitigation of CH4 emissions from rewetted fens.

scholarly journals Effect of Soil Type and Nitrogen Rate on Growth of Annual and Perennial Landscape Plants in Florida

2014 ◽  
Vol 24 (6) ◽  
pp. 724-730 ◽  
Author(s):  
Kimberly A. Moore ◽  
Amy L. Shober ◽  
Gitta Hasing ◽  
Christine Wiese ◽  
Nancy G. West
Keyword(s):  
Plant Species ◽  
Warm Season ◽  
Dry Weight ◽  
Soil Condition ◽  
Soil Conditions ◽  
Perennial Species ◽  
Aesthetic Quality ◽  
Shoot Dry Weight ◽  
Quality Response ◽  
The Impact

Previous research indicated that acceptable quality annual and perennial plant species can be grown in the landscape with low nitrogen (N) inputs. However, information on the impact of soil conditions and N use by ornamental plants grown in central Florida is lacking in the literature. Our objective was to evaluate plant growth and quality response of eight warm-season annuals, seven cool-season annuals, and four herbaceous perennial species to a range of N fertilizer rates when plants were grown in landscape beds containing native field soil or subsoil fill. A slow-release N source (42N–0P–0K) was applied every 12 weeks at annual N rates of 3, 5, or 7 lb/1000 ft2 for a period of 18 weeks (annual species) or 1, 3, or 5 lb/1000 ft2 for a period of 54 weeks (perennial species). Plants were evaluated for aesthetic quality every 6 weeks and shoot dry weight was measured at completion of the experiment. Dry weight production and aesthetic quality of most species evaluated was unaffected by N rate. For several species, shoot dry weight was higher when planted in the field plots containing native soil [alyssum (Lobularia maritima) ‘Bada Bing White’ wax begonia (Begonia ×semperflorens-cultorum), dahlberg daisy (Thymophylla tenuiloba), ‘Survivor Hot Pink’ geranium (Pelargonium ×hortorum), gomphrena (Gomphrena globosa), ‘Blue Puffs Improved’ (‘Blue Danube’) ageratum (Ageratum houstonianum), blanket flower (Gaillardia pulchella), goldenrod (Solidago chapmanii), ‘Mystic Spires’ salvia (Salvia longispicata ×farinacea)]. Quality response to soil condition was mixed over the course of the study. Several species performed as well (or better) in the field as when planted in the subsoil fill soils. These results illustrate that some landscape plant species are able to survive and thrive under various soil and fertility conditions. These “tougher” species may be good choices for installation in landscapes with marginal native soils or disturbed urban landscape soils.

The methodological approach for the determination of the pressure of artificial raindrops as a question of the theory of splash soil erosion

2020 ◽  
pp. 24-28
Author(s):  
Mihail Zver'kov
Keyword(s):  
Block Diagram ◽  
Methodological Approach ◽  
Control Measures ◽  
Soil Conditions ◽  
Effective Pressure ◽  
Long Distance ◽  
Splash Erosion ◽  
Rain Drops ◽  
Artificial Rain ◽  
The Impact

To the article the results of the theoretical and experimental researches are given on questions of estimates of the dynamic rate effect of raindrop impact on soil. The aim of this work was to analyze the current methods to determine the rate of artificial rain pressure on the soil for the assessment of splash erosion. There are the developed author’s method for calculation the pressure of artificial rain on the soil and the assessment of splash erosion. The study aims to the justification of evaluation methods and the obtaining of quantitative characteristics, prevention and elimination of accelerated (anthropogenic) erosion, the creation and the realization of the required erosion control measures. The paper considers the question of determining the pressure of artificial rain on the soil. At the moment of raindrops impact, there is the tension in the soil, which is called vertical effective pressure. It is noted that the impact of rain drops in the soil there are stresses called vertical effective pressure. The equation for calculation of vertical effective pressure is proposed in this study using the known spectrum of raindrops. Effective pressure was 1.4 Pa for the artificial rain by sprinkler machine «Fregat» and 5.9 Pa for long distance sprinkler DD-30. The article deals with a block diagram of the sequence for determining the effective pressure of rain drops on the soil. This diagram was created by the author’s method of calculation of the effective pressure of rain drops on the soil. The need for an integrated approach to the description of the artificial rain impact on the soil is noted. Various parameters characterizing drop erosion are considered. There are data about the mass of splashed soil in the irrigation of various irrigation machinery and installations. For example, the rate (mass) of splashed soil was 0.28…0.78 t/ha under irrigation sprinkler apparatus RACO 4260–55/701C in the conditions of the Ryazan region. The method allows examining the environmental impact of sprinkler techniques for analyzes of the pressure, caused by raindrops, on the soil. It can also be useful in determining the irrigation rate before the runoff for different types of sprinkler equipment and soil conditions.

Heterotrophic Kinetic Parameter Estimation for Enhanced Biological Phosphorus Removal Processes Operated in Conventional and Membrane-Assisted Modes

2006 ◽  
Vol 41 (1) ◽  
pp. 72-83 ◽  
Author(s):  
Zhe Zhang ◽  
Eric R. Hall
Keyword(s):  
Parameter Estimation ◽  
Phosphorus Removal ◽  
Growth Yield ◽  
Pilot Scale ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Nitrogen And Phosphorus ◽  
Parameter Values ◽  
The Impact ◽  
Biological Phosphorus

Abstract Parameter estimation and wastewater characterization are crucial for modelling of the membrane enhanced biological phosphorus removal (MEBPR) process. Prior to determining the values of a subset of kinetic and stoichiometric parameters used in ASM No. 2 (ASM2), the carbon, nitrogen and phosphorus fractions of influent wastewater at the University of British Columbia (UBC) pilot plant were characterized. It was found that the UBC wastewater contained fractions of volatile acids (SA), readily fermentable biodegradable COD (SF) and slowly biodegradable COD (XS) that fell within the ASM2 default value ranges. The contents of soluble inert COD (SI) and particulate inert COD (XI) were somewhat higher than ASM2 default values. Mixed liquor samples from pilot-scale MEBPR and conventional enhanced biological phosphorus removal (CEBPR) processes operated under parallel conditions, were then analyzed experimentally to assess the impact of operation in a membrane-assisted mode on the growth yield (YH), decay coefficient (bH) and maximum specific growth rate of heterotrophic biomass (µH). The resulting values for YH, bH and µH were slightly lower for the MEBPR train than for the CEBPR train, but the differences were not statistically significant. It is suggested that MEBPR simulation using ASM2 could be accomplished satisfactorily using parameter values determined for a conventional biological phosphorus removal process, if MEBPR parameter values are not available.

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