scholarly journals Effects of the Invasive Tree Species Ailanthus altissima on the Floral Diversity and Soil Properties in the Pannonian Region

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1155
Author(s):  
András Demeter ◽  
Dénes Saláta ◽  
Eszter Tormáné Kovács ◽  
Orsolya Szirmai ◽  
Petra Trenyik ◽  
...  
Keyword(s):  
Ailanthus Altissima ◽  
Soil Parameters ◽  
Canopy Layer ◽  
Ammonia Content ◽  
Shrub Layer ◽  
Floral Diversity ◽  
Floor Layer ◽  
Biogeographical Region ◽  
Invasive Tree Species ◽  
The Impact

Tree-of-heaven (Ailanthus altissima) is one of the most dangerous and widespread invasive woody plant species in Europe. Despite the fact that A. altissima is in the focus of an increasing number of research projects, the impact of its mass spread on native vegetation, its diversity, and changes in soil quality are still incomplete. The current study addresses the effects of this invasive species on plant diversity and soil parameters simultaneously. The main objective of our research is to determine the impact of cover and mass of A. altissima on the diversity of each forest layer; the examined soil parameters and on other selected environmental variables. For botanical and pedological investigations we selected nine A. altissima-dominated sites in Central Europe, in the Pannonian Biogeographical Region. Based on our results, it can be stated that fully grown A. altissima-dominated stands can displace other taxa by their shading and allelopathy, thereby reducing canopy layer diversity. The increase in the species richness of the shrub layer had a positive correlation with the diversity of the floor layer and also with the humus and ammonia content of the soil. As the diversity of shrub layer and floor layer positively correlated with many soil parameters, the diverse vegetation of these layers can represent a potential opportunity for the regeneration of areas infected with A. altissima.

scholarly journals Evaluation of P-Band SAR Tomography for Mapping Tropical Forest Vertical Backscatter and Tree Height

2021 ◽  
Vol 13 (8) ◽  
pp. 1485
Author(s):  
Naveen Ramachandran ◽  
Sassan Saatchi ◽  
Stefano Tebaldini ◽  
Mauro Mariotti d’Alessandro ◽  
Onkar Dikshit
Keyword(s):  
Tropical Forest ◽  
Vertical Profile ◽  
Mean Squared Error ◽  
Low Frequency ◽  
Tree Height ◽  
Canopy Layer ◽  
Local Maxima ◽  
Slope Correction ◽  
Compensation Approach ◽  
The Impact

Low-frequency tomographic synthetic aperture radar (TomoSAR) techniques provide an opportunity for quantifying the dynamics of dense tropical forest vertical structures. Here, we compare the performance of different TomoSAR processing, Back-projection (BP), Capon beamforming (CB), and MUltiple SIgnal Classification (MUSIC), and compensation techniques for estimating forest height (FH) and forest vertical profile from the backscattered echoes. The study also examines how polarimetric measurements in linear, compact, hybrid, and dual circular modes influence parameter estimation. The tomographic analysis was carried out using P-band data acquired over the Paracou study site in French Guiana, and the quantitative evaluation was performed using LiDAR-based canopy height measurements taken during the 2009 TropiSAR campaign. Our results show that the relative root mean squared error (RMSE) of height was less than 10%, with negligible systematic errors across the range, with Capon and MUSIC performing better for height estimates. Radiometric compensation, such as slope correction, does not improve tree height estimation. Further, we compare and analyze the impact of the compensation approach on forest vertical profiles and tomographic metrics and the integrated backscattered power. It is observed that radiometric compensation increases the backscatter values of the vertical profile with a slight shift in local maxima of the canopy layer for both the Capon and the MUSIC estimators. Our results suggest that applying the proper processing and compensation techniques on P-band TomoSAR observations from space will allow the monitoring of forest vertical structure and biomass dynamics.

scholarly journals Deep Neural Network and Polynomial Chaos Expansion-Based Surrogate Models for Sensitivity and Uncertainty Propagation: An Application to a Rockfill Dam

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1830
Author(s):  
Gullnaz Shahzadi ◽  
Azzeddine Soulaïmani
Keyword(s):  
Polynomial Chaos ◽  
Complex Structure ◽  
Uncertainty Propagation ◽  
Surrogate Models ◽  
Polynomial Chaos Expansion ◽  
Soil Parameters ◽  
Chaos Expansion ◽  
Rockfill Dam ◽  
Parametric Studies ◽  
The Impact

Computational modeling plays a significant role in the design of rockfill dams. Various constitutive soil parameters are used to design such models, which often involve high uncertainties due to the complex structure of rockfill dams comprising various zones of different soil parameters. This study performs an uncertainty analysis and a global sensitivity analysis to assess the effect of constitutive soil parameters on the behavior of a rockfill dam. A Finite Element code (Plaxis) is utilized for the structure analysis. A database of the computed displacements at inclinometers installed in the dam is generated and compared to in situ measurements. Surrogate models are significant tools for approximating the relationship between input soil parameters and displacements and thereby reducing the computational costs of parametric studies. Polynomial chaos expansion and deep neural networks are used to build surrogate models to compute the Sobol indices required to identify the impact of soil parameters on dam behavior.

Restoration of floral diversity through plantations on abandoned agricultural land

2006 ◽  
Vol 36 (5) ◽  
pp. 1218-1235 ◽  
Author(s):  
Steven G Newmaster ◽  
F Wayne Bell ◽  
Christopher R Roosenboom ◽  
Heather A Cole ◽  
William D Towill
Keyword(s):  
Plant Diversity ◽  
Tree Species ◽  
Agricultural Land ◽  
Structural Diversity ◽  
Geographic Region ◽  
Natural Forests ◽  
Community Interactions ◽  
Long Term Study ◽  
Floral Diversity ◽  
The Impact

Plantations have been claimed to be "monocultures", or "biological deserts". We investigated these claims in the context of a long-term study on plant diversity within plantations with different indigenous tree species, spacings, and soil types that were compared with 410 native stands. Soil type had no influence on plantation species diversity or abundance, and wider spacing resulted in higher richness, lower woody plant abundance, slightly higher cover of herbaceous plants, and large increases in cryptogam cover. We also found a canopy species × spacing interaction effect, where the impact of increased spacing on understory vegetation was more pronounced in spruce than in pine plantations. The dynamic community interactions among species of feathermoss appear to be in response to the physical impediment from varying amounts of needle rain from the different tree species. High light interception and needle fall were negatively correlated with understory plant diversity, as was lack of structural diversity. This study indicates that through afforestation efforts agricultural lands can be restored to productive forests that can harbour nearly one-half of the plant species found in equivalent natural forests within the same geographic region in as little as 50 years. We recommend applying afforestation using indigenous conifer species as a first step towards rehabilitating conifer forests that have been converted to agriculture and subsequently abandoned.

Impact of random soil properties on stress–strain response

2004 ◽  
Vol 41 (2) ◽  
pp. 351-355 ◽  
Author(s):  
Dieter Stolle ◽  
Peijun Guo ◽  
Gabriel Sedran
Keyword(s):  
Soil Properties ◽  
Constitutive Modelling ◽  
Soil Parameters ◽  
Strain Response ◽  
Constitutive Behaviour ◽  
Stress Strain ◽  
Deterministic Analysis ◽  
Model Predictions ◽  
Random Variability ◽  
The Impact

This paper analyzes the impact of natural random variation of soil properties on the constitutive modelling of geomaterial behaviour. A theoretical framework for accommodating variation in soil properties is presented. The framework is then used to examine the consequence of parameter variability on stress–strain relations. An important observation is that average soil parameters from a series of tests on small specimens, in which density of the specimens varies randomly, do not necessarily reflect the average constitutive behaviour of soil. Model predictions are shown to be consistent with the experimental data.Key words: random variability, deterministic analysis, soil parameters, constitutive model.

scholarly journals Application of the SWAT (Soil and Water Assessment Tool) model in the Ronnea catchment of Sweden

2013 ◽  
Vol 7 (3) ◽  
pp. 252-257
Keyword(s):  
Input Data ◽  
Management Practices ◽  
Assessment Tool ◽  
Swat Model ◽  
Soil Parameters ◽  
Daily Step ◽  
Calibration And Validation ◽  
The Impact ◽  
Water Assessment ◽  
Soil And Water

The subject of this article is the estimation of quantitative (hydrological) and qualitative parameters in the catchment of Ronnea (1800 Km2, located in south western Sweden) through the application of the Soil and Water Assessment Tool (SWAT). SWAT is a river basin model that was developed for the U.S.D.A. Agricultural Research Service, by the Blackland Research Center in Texas. The SWAT model is a widely known tool that has been used in several cases world-wide. It has the ability to predict the impact of land management practices on water, sediment and agricultural chemical yield in large complex watersheds. The present work investigates certain capabilities of the SWAT model which have not identified up to now. More in specific, the main targets of the work carried out are the following: • Identification of the existing hydrological and qualitative conditions • Preparation - Processing of data required to be used as input data of the model • Hydrological calibration - validation of the model, in 7 subbasins of the Catchment of Ronnea • Estimation and evaluation of the simulated qualitative parameters of the model All available data were offered by the relevant Institutes of Sweden, in the framework of the European program EUROHARP. The existing conditions in the catchment of Ronnea, are described in detail including topography, land uses, soil types, pollution sources, agricultural management practices, precipitation, temperature, wind speed, humidity, solar radiation as well as observed discharges and Nitrogen and Phosphorus substances concentrations. Most of the above data were used as input data for the application of SWAT model. Adequate methods were also used to complete missing values in time series and estimate additional parameters (such as soil parameters) required by the model. Hydrological calibration and validation took place for each outlet of the 7 subbasins of Ronnea catchment in an annual, monthly and daily step. The calibration was achieved by estimating parameters related to ground water movement and evaluating convergence between simulated and observed discharges by using mainly the Nash & Sutcliffe coefficient (NTD). Through the sensitivity analysis, main parameters of the hydrological simulation, were detected. According to the outputs of the SWAT model, the water balance of Ronnea catchment was also estimated. Hydrological calibration and validation is generally considered sufficient in an annual and monthly step. Hydrological calibration – validation in daily step, generally does not lead to high values of the NTD indicator. However, when compared to results obtained by the use of SWAT in Greece, a relatively high value of NTD is achieved in one subbasin. Finally, a comparison between the simulated and observed concentrations of total Phosphorus and Nitrogen was carried out.

scholarly journals Assessment of Soil Fertility and Crop Nutrient Status in Agricultural Soils Near a Brick Kiln Cluster

2020 ◽  
Vol 13 (1) ◽  
pp. 122
Author(s):  
Nasrin Chowdhury ◽  
Md. Mamunur Rasid
Keyword(s):  
Heavy Metal ◽  
Nutritional Status ◽  
Agricultural Soils ◽  
Risk Index ◽  
Contamination Factor ◽  
Nutrition Status ◽  
Soil Parameters ◽  
Optimum Level ◽  
Brick Kiln ◽  
The Impact

Brick kiln exhaust when deposited can hamper the nutritional status of the agricultural soils and crops. To study the impact, soil and associated plant samples were collected from the vicinity of a brick kiln cluster in Chattogram, Bangladesh. The soil contamination was evaluated by heavy metal indices. Agricultural soils close to the brick kiln area were very strongly acid to slightly acid. Organic carbon, total nitrogen and available phosphorus content of the agriculture soils near brick kiln cluster were 0.35% to 1.01%, 0.10 to 0.24% and 2.21 to 13.48 mg kg-1 respectively and the significant different mean value of 0.70%, 0.22% and 14.65 mg kg-1 respectively in the reference soil. The nutritional status of sampling sites was lower than the previously reported data. The nutrition status of the plants was at an optimum level as regular fertilizer application was practiced but showed an irregular pattern along with all the soil parameters and heavy metal indices. The contamination factor (Cd), potential ecological risk index (PER) and geo-accumulation index (Igeo) demonstrated that the agricultural soils in the vicinity of the brick kiln cluster were moderately- to highly-polluted. This indicates the deterioration of soil quality by uncontrolled brick kiln operation.

scholarly journals Influence of Soil Parameters on Detecting Voids behind a Tunnel Lining Using an Impact Echo Method

2019 ◽  
Vol 9 (24) ◽  
pp. 5403
Author(s):  
Meng Ma ◽  
Rongning Cao ◽  
Chao Niu ◽  
Hougui Zhang ◽  
Weining Liu
Keyword(s):  
Element Model ◽  
Tunnel Lining ◽  
Parameter Analysis ◽  
Soil Parameters ◽  
Impact Echo ◽  
Time Frequency ◽  
Box Counting ◽  
Box Counting Dimension ◽  
Frequency Domains ◽  
The Impact

Tunnel lining cavities are a common problem that may affect the bearing capacity of the tunnel-supporting structure, as well as the tunnel service life. The impact echo (IE) method can be used to detect voids behind tunnel linings. For a long tunnel, the surrounding rocks/soils are inhomogeneous and anisotropic, with parameters that vary with tunnel mileages. It is interesting to analyse whether alterations of the soil parameters affect the non-destructive test results. A laboratory experiment was performed in this study, in which voids behind a concrete plate, representing the tunnel lining, were designed to model the ineffective contact between the soil and the tunnel. The IE method was employed to inspect the existence of the void using different signal analysis approaches in the time, frequency and time–frequency domains. Furthermore, the fractal box-counting dimension was calculated for the purpose of quantitative evaluation. Different soil parameters and void sizes were considered, and finally, a finite element model was built and parameter analysis was accomplished using the software ABAQUS. The results demonstrated that: (1) A comprehensive analysis of vibration signals in the time, frequency and time–frequency domains was useful for identifying voids, while the box-counting dimension was useful for evaluating voids quantitatively. (2) Soils with large density and Young’s modulus differences had a certain influence on void detection, while those with large water content and Poisson’s ratio differences had little influence. (3) The box-counting dimension value was stable within the area where the void existed behind the tunnel; when the detection point was beyond twice that of the void dimension, it was difficult to locate the void.

scholarly journals Assessment of the Quality of Soil and Groundwater of the Agricultural Area of Sidi Yahya Region, Morocco

2020 ◽  
Vol 150 ◽  
pp. 01001
Author(s):  
M. Lahmar ◽  
N. El Khodrani ◽  
S. Omrania ◽  
H. Dakak ◽  
R. Moussadek ◽  
...  
Keyword(s):  
Water Table ◽  
Land Management ◽  
Research Work ◽  
Sustainable Use ◽  
Soil Samples ◽  
Agricultural Area ◽  
Soil Parameters ◽  
The Impact ◽  
Soil And Water

The Gharb plain is the largest agricultural area in Morocco. It is characterized by fertile soils and the availability of water either from surface or groundwater which allowed intensive agriculture. The aim of this research work is to study the impact of this land management on the quality of water and soil. The study was done for the irrigated perimeter of Sidi Yahya belonging to the province of Sidi Slimane, Gharb (Morocco). Depth of water table and water pH were measured in situ while water and soil samples were collected and brought to the laboratory for their physico-chemical analyses. Sampling of 33water wells and soil samples, from six different zones, was done between May and October 2018. Analysis of variance (ANOVA) was used to check if mean water and soil parameters differed between zones. The results showed that the minimal and maximal water table depth were 6 and 96 m, respectively. Also, slightly more than half of the wells (51.5%) were inadequate for irrigation since they were either highly or extremely saline. Furthermore, soils were poor to moderately poor in organic matter but very rich in potassium and the phosphorus content was highly variable. Based on the statistical analysis, it is clear that the six zones had significantly different means for CaCO3, pH, OM, and exchangeable sodium percentage. Soil degradation like pollution and salinization may occur in this region if poor quality water is used for irrigation and if land is mismanaged. This research work can be considered as a first step towards a program for monitoring the quality of soil and water for adapting the land management with the final objective of securing high productivity and sustainable use of soil and water resources.

scholarly journals Changes in Soil Hydro-Physical Properties and SOM Due to Pine Afforestation and Grazing in Andean Environments Cannot Be Generalized

Forests ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 17 ◽  
Author(s):  
Franklin Marín ◽  
Carlos Dahik ◽  
Giovanny Mosquera ◽  
Jan Feyen ◽  
Pedro Cisneros ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Physical Properties ◽  
Soil Properties ◽  
Water Retention ◽  
Soil Parameters ◽  
Water Retention Capacity ◽  
Sampling Depth ◽  
Site Specific ◽  
The Impact

Andean ecosystems provide important ecosystem services including streamflow regulation and carbon sequestration, services that are controlled by the water retention properties of the soils. Even though these soils have been historically altered by pine afforestation and grazing, little research has been dedicated to the assessment of such impacts at local or regional scales. To partially fill this knowledge gap, we present an evaluation of the impacts of pine plantations and grazing on the soil hydro-physical properties and soil organic matter (SOM) of high montane forests and páramo in southern Ecuador, at elevations varying between 2705 and 3766 m a.s.l. In total, seven study sites were selected and each one was parceled into undisturbed and altered plots with pine plantation and grazing. Soil properties were characterized at two depths, 0–10 and 10–25 cm, and differences in soil parameters between undisturbed and disturbed plots were analyzed versus factors such as ecosystem type, sampling depth, soil type, elevation, and past/present land management. The main soil properties affected by land use change are the saturated hydraulic conductivity (Ksat), the water retention capacity (pF 0 to 2.52), and SOM. The impacts of pine afforestation are dependent on sampling depth, ecosystem type, plantation characteristics, and previous land use, while the impacts of grazing are primarily dependent on sampling depth and land use management (grazing intensity and tilling activities). The site-specific nature of the found relations suggests that extension of findings in response to changes in land use in montane Andean ecosystems is risky; therefore, future evaluations of the impact of land use change on soil parameters should take into consideration that responses are or can be site specific.

scholarly journals Gypsum, Soil Scarification and Succession Planting as Alternatives to Mitigate Compaction of Dystrophic Red-Yellow Latosol

2018 ◽  
Vol 10 (8) ◽  
pp. 277
Author(s):  
Eduardo Antonio Neves dos Santos ◽  
Milton César Costa Campos ◽  
Jose Mauricio da Cunha ◽  
Fernando Gomes de Souza ◽  
Paulo Guilherme Salvador Wadt ◽  
...  
Keyword(s):  
Block Design ◽  
Total Porosity ◽  
Penetration Resistance ◽  
Soil Parameters ◽  
Soil Density ◽  
Randomized Block Design ◽  
Soil Scarification ◽  
Physical Attributes ◽  
Sustainable Agricultural Systems ◽  
The Impact

Understanding and quantifying the impact of soil management and use on its physical properties are essential to the development of sustainable agricultural systems. Thus, the aim of this study was to assess the effect of agricultural gypsum, soil scarification and succession planting on the physical attributes of dystrophic red-yellow latosol in Porto Velho, Rondônia state (RO), Brazil. The treatments used were absence and application of 2000 kg ha-1 of gypsum, absence and use of soil scarification, and three types of crop succession: SF (soybean/fallow), SMF (soybean/maize/fallow) and SMBF (soybean/maize/brachiaria/fallow). A randomized block design was used on eight blocks, for a 2 × 2 × 3 factorial arrangement. Soil parameters assessed were macroporosity, microporosity, total porosity, soil density, moisture content and penetration resistance. Data normality was assessed using the Shapiro-Wilk test. The data were submitted to analysis of variance and means were compared by the Scott-Knott test at 5% probability. The highest macroporosity and total porosity values were recorded in treatments with gypsum application and soil scarification. Penetration resistance was lower in the SMBF and SMF crop successions. There was no treatment effect on the soil density.

Sign in / Sign up

Export Citation Format

Share Document