scholarly journals Inundation depth and duration impacts on wetland soils and vegetation : state of knowledge

2021 ◽  
Author(s):  
Glenn Suir ◽  
Jacob Berkowitz
Keyword(s):  
Ecosystem Restoration ◽  
Feedback Loops ◽  
Future Research ◽  
Wetland Ecosystems ◽  
Soil Response ◽  
Inundation Depth ◽  
Hydrologic Regimes ◽  
Soil Responses ◽  
Source Materials ◽  
Water Depths

The following synthesizes studies investigating plant and soil responses to increased inundation in order to support ecosystem restoration efforts related to the alteration of natural wetland hydrodynamics. Specific topics include hydrologic regimes, soil response to inundation, and implications for vegetation communities exposed to increased water depths. Results highlight the important interactions between water, soils, and vegetation that determine the trajectory and fate of wetland ecosystems, including the development of feedback loops related to marsh degradation and subsidence. This report then discusses the knowledge gaps related to implications of inundation depth, timing, and duration within an ecosystem restoration context, identifying opportunities for future research while providing source materials for practitioners developing restoration projects.

Primary Drivers of Reptile Overwintering Habitat Suitability: Integrating Wetland Ecohydrology and Spatial Complexity

BioScience ◽  
2020 ◽  
Vol 70 (7) ◽  
pp. 597-609
Author(s):  
Chantel E Markle ◽  
Paul A Moore ◽  
James M Waddington
Keyword(s):  
Land Use ◽  
Habitat Suitability ◽  
Land Use Changes ◽  
Conservation Strategies ◽  
Future Research ◽  
Habitat Availability ◽  
Freshwater Turtles ◽  
Wetland Ecosystems ◽  
Winter Conditions

Abstract Identifying ecosystems resilient to climate and land-use changes is recognized as essential for conservation strategies. However, wetland ecosystems may respond differently to stressors depending on their successional state and the strength of ecohydrological feedbacks resulting in fluctuations in habitat availability and suitability. Long-term habitat suitability is necessary for the persistence of wetland-dependent species and a key characteristic of climatic refugia. In the present article, we review and synthesize biogeochemical, thermal, ecological, and hydrological feedbacks and interactions that operate within wetlands and, consequently, regulate overwintering suitability for many freshwater turtles and snakes. We propose that understanding the breadth and interconnected nature of processes controlling temperature, dissolved oxygen, and water table position are vital for the conservation of northern reptile populations that depend on wetlands to survive winter conditions. Finally, we suggest that our integrated framework can guide future research and the management of wetland ecosystems in an era of unprecedented change.

scholarly journals Reviews and syntheses: Soil responses to manipulated precipitation changes – an assessment of meta-analyses

2020 ◽  
Vol 17 (14) ◽  
pp. 3859-3873 ◽  
Author(s):  
Akane O. Abbasi ◽  
Alejandro Salazar ◽  
Youmi Oh ◽  
Sabine Reinsch ◽  
Maria del Rosario Uribe ◽  
...  
Keyword(s):  
Soil Phosphorus ◽  
Nitrogen And Phosphorus ◽  
Holistic View ◽  
Soil Response ◽  
Carbon And Nitrogen ◽  
Wide Range ◽  
Scientific Attention ◽  
Meta Analyses ◽  
Precipitation Changes ◽  
Soil Responses

Abstract. In the face of ongoing and projected climatic changes, precipitation manipulation experiments (PMEs) have produced a wealth of data about the effects of precipitation changes on soils. In response, researchers have undertaken a number of synthetic efforts. Several meta-analyses have been conducted, each revealing new aspects of soil responses to precipitation changes. Here, we conducted a comparative analysis of the findings of 16 meta-analyses focused on the effects of precipitation changes on 42 soil response variables, covering a wide range of soil processes. We examine responses of individual variables as well as more integrative responses of carbon and nitrogen cycles. We find strong agreement among meta-analyses that belowground carbon and nitrogen cycling accelerate under increased precipitation and slow under decreased precipitation, while bacterial and fungal communities are relatively resistant to decreased precipitation. Much attention has been paid to fluxes and pools in carbon, nitrogen, and phosphorus cycles, such as gas emissions, soil carbon, soil phosphorus, extractable nitrogen ions, and biomass. The rates of processes underlying these variables (e.g., mineralization, fixation, and (de)nitrification) are less frequently covered in meta-analytic studies, with the major exception of respiration rates. Shifting scientific attention to these less broadly evaluated processes would deepen the current understanding of the effects of precipitation changes on soil and provide new insights. By jointly evaluating meta-analyses focused on a wide range of variables, we provide here a holistic view of soil responses to changes in precipitation.

Response of a Porous Seabed Under Random Wave Loading

2006 ◽  
Author(s):  
Haijiang Liu ◽  
Dong-S. Jeng
Keyword(s):  
Soil Parameters ◽  
Random Wave ◽  
Wave Loading ◽  
Random Waves ◽  
Regular Waves ◽  
Offshore Pipelines ◽  
Soil Response ◽  
Significant Difference ◽  
Wave Induced ◽  
Soil Responses

The evaluation of the wave-induced soil response is particularly important for many coastal engineering installations such as offshore pipelines, platforms and breakwaters. Most previous investigations have been limited to the linear regular wave loading, even though the real situation is under random waves. In this study, we propose a semi-analytical solution for the random wave-induced pore pressure and effective stresses in marine sediments. Based on the new analytical solutions, different soil responses under the random wave loading are investigated and compared with the corresponding results under the linear regular waves. Numerical examples demonstrate the significant difference on wave-induced seabed response between these two wave loadings due to the irregularity introduced by the random waves. Finally, the influence of several soil parameters on the soil response under random wave loading is also examined.

Soil responses to sodicity and salinity: challenges and opportunities

Soil Research ◽  
2001 ◽  
Vol 39 (6) ◽  
pp. 1219 ◽  
Author(s):  
J. D. Oster ◽  
I. Shainberg
Keyword(s):  
Organic Matter Content ◽  
Matter Content ◽  
Soil Permeability ◽  
Soil Response ◽  
Low Salinity ◽  
Main Challenge ◽  
Challenges And Opportunities ◽  
Physical Response ◽  
Soil Responses ◽  
Wetting Rate

Exchangeable sodium and low salinity deteriorate the permeability of soils to air and water. The susceptibility of soils to sodicity and low salinity depend on both the inherent properties of the soils (e.g. texture, mineralogy, pH, CaCO3, sesquioxides, and organic matter content) and extrinsic, time-dependent properties (e.g. cultivation, irrigation method and wetting rate, antecedent water content, and the time since cultivation). Whereas the effect of inherent soil properties on the soil response to sodicity has been studied and modelled, especially under laboratory conditions, the effect of soil management on the physical response of soils to sodicity has been studied very little. Consequently our ability to predict the changes in soil permeability under field conditions is limited. Including the effect of management on the physical response of soils to sodicity and low salinity is the main challenge facing researchers, consultants, and farmers.

scholarly journals Прогресс исследований за последние годы нелинейных свойств грунтов за последние годы в России и на Тайване

2020 ◽  
Author(s):  
Huang Jyun-Yan ◽  
V.B. Zaalishvili ◽  
D.A. Melkov ◽  
Kuo Chun-Hsiang ◽  
Wen Kuo-Liang ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Strain Curve ◽  
Machine Learning Techniques ◽  
Design Parameters ◽  
Future Research ◽  
Response Analysis ◽  
Empirical Formulas ◽  
Absorption Mechanism ◽  
Soil Response ◽  
Soil Nonlinearity

Soil nonlinearity has a significant influence on result seismic effect at strong motions which differ from weak and moderate ones. Practice of construction faced with adequate account of nonlinear effect in weak soils and demand techniques for design parameters assessment. Researches of recent years in the field of soil nonlinearity may enrich each other and find the main way for effective practices and building codes regularization. The aim of this work is allocation of parameters for nonlinearity description and corresponding techniques development. Methods.Field soil response analysis with sources of different power in conjunction with strong motion records were analyzed by means of regression analysis and other machine learning techniques. Mathematical modeling includes multiple reflected waves analysis technique and finite elements modeling. Results. The parameters that are closely related to the absorption and soil nonlinearity were identified. The empirical formulas connecting the areas of normalized and real spectra with the parameters of seismic loadings were obtained using regression analysis. The differences of absorption mechanism in dispersed (soft) and rocky soils were defined. Conclusion.The models of ground strata behavior in the case of variable intensity of dynamic action on the basis of consideration of the real area of the spectrum and the average value of the frequency, characterized by a linear and nonlinear elastic-inelastic deformation of the soils are offered. Degree of nonlinearity (DNL) metric may be efficiently used for stress-strain curve assessment, and in the absence of strong earthquakes records it can be applied for powerful seismic sources records analysis what determines the direction of future research. Нелинейные свойства грунтов оказывают существенное влияние на результат сейсмического воздействия при сильных движениях, которые отличаются от слабых и умеренных. Практика строительства столкнулась с необходимостью адекватного учета эффекта нелинейности в слабых грунтах и методики оценки проектных параметров. Исследования нелинейных свойств грунтов проведенные за последние годы могут обогатить друг друга и найти основной путь для эффективной практики и регуляризации строительных норм. Целью работы является выделение параметров для описания нелинейности и разработки соответствующих методик. Методы исследования. Был проанализирован отклик грунта в полевых условиях с источниками различной мощности в сочетании с записями сильных движений с помощью регрессионного анализа и других методов машинного обучения. Математическое моделирование включает в себя метод анализа многократно отраженных волн и моделирование методом конечных элементов. Результаты. Были определены параметры, тесно связанные с поглощением и нелинейностью грунтов. С помощью регрессионного анализа были получены эмпирические формулы, связывающие области нормированного и реального спектров с параметрами сейсмических нагрузок. Выявлены различия механизма поглощения в дисперсных (рыхлых) и каменистых грунтах. Выводы. Предложены модели поведения наземных пластов при переменной интенсивности динамического воздействия на основе учета реальной площади спектра и среднего значения частоты, характеризующейся линейной и нелинейной упруго-неупругой деформацией грунтов. Критерий степени нелинейности (DNL) может быть эффективно использован для оценки кривой напряжения-деформации, а в отсутствие записей сильных землетрясений он может применяться для анализа записей мощных сейсмических источников, определяющих направление будущих исследований.

scholarly journals Soil responses to manipulated precipitation changes: A synthesis of meta-analyses

2020 ◽  
Author(s):  
Akane O. Abbasi ◽  
Alejandro Salazar ◽  
Youmi Oh ◽  
Sabine Reinsch ◽  
Maria del Rosario Uribe ◽  
...  
Keyword(s):  
Soil Phosphorus ◽  
Nitrogen And Phosphorus ◽  
Holistic View ◽  
Soil Response ◽  
Carbon And Nitrogen ◽  
Wide Range ◽  
Scientific Attention ◽  
Meta Analyses ◽  
Precipitation Changes ◽  
Soil Responses

Abstract. In the face of ongoing and projected precipitation changes, precipitation manipulation experiments (PMEs) have produced a wealth of data about the effects of precipitation changes on soils. In response, researchers have undertaken a number of synthetic efforts. Several meta-analyses have been conducted, each revealing new aspects of soil responses to precipitation changes. We synthesize the findings of 16 meta-analyses focused on the effects of decreased and increased precipitation on 42 soil response variables, covering a wide range of soil processes and examining responses of individual variables as well as more integrative responses of carbon and nitrogen cycles. We found a strong agreement among meta-analyses that decreased and increased precipitation inhibits and promotes belowground carbon and nitrogen cycling, respectively, while microbial communities are relatively resistant to precipitation changes. Much attention has been paid to fluxes and pools in carbon, nitrogen, and phosphorus cycles, such as gas emissions, soil carbon, soil phosphorus, extractable nitrogen ions, and biomass, but the rates of processes underlying these variables are less frequently covered in meta-analytic studies (e.g., rates of mineralization, fixation, and de/nitrification). Shifting scientific attention to these “processes” would, therefore, deepen the current understanding of the effects of precipitation changes on soil and provide new insights. By comparing meta-analyses focused on different variables, we provide here a quantitative and holistic view of soil responses to changes in precipitation.

Sentiment Analysis Techniques, Tools, Applications, and Challenge

2020 ◽  
pp. 35-48
Author(s):  
Chitra A. Dhawale ◽  
Vandana V. Chaudhari
Keyword(s):  
Natural Language ◽  
Sentiment Analysis ◽  
Customer Service ◽  
Computational Linguistics ◽  
Language Processing ◽  
Marketing Research ◽  
Research Direction ◽  
Future Research ◽  
Source Materials

Sentiment (opinion) refers to the feelings of a human being, which are generally reflected through speech and writing in a particular natural language. The analysis of these sentiments are therefore carried with the help of natural language processing, text analysis, and computational linguistics to identify and extract subjective information in source materials. Generally speaking, sentiment analysis aims to determine the attitude of a speaker or a writer with respect to some topic or the overall contextual polarity of a document. Sentiment analysis is widely applied to reviews and social media for a variety of applications, ranging from marketing research, political reviews, policy making, decision making, customer service, etc. In this chapter the authors include the introduction to sentiment analysis, various approaches for classification of sentiment analysis, various tools used, the application areas, challenges, and future research direction in this most demanding area.

scholarly journals Evaluation of the Soil Response to the Successive Application of Aqueous Extracts from Canavalia Ensiformis Leaves Used as a Post-emergent Bioherbicide

2017 ◽  
Vol 5 (2) ◽  
pp. 15
Author(s):  
Darlan Ferreira Silva ◽  
Maria Olimpia Oliveira Rezende
Keyword(s):  
Crop Residues ◽  
Degradation Products ◽  
Direct Application ◽  
Aqueous Extracts ◽  
Target Species ◽  
Additional Risk ◽  
Soil Response ◽  
Final Destination ◽  
Culture Cycle ◽  
Soil Responses

Soil is normally the final destination of pesticides applied to cultures. After a series of applications, various pesticides reach the soil due to direct application or leaf washing. However, some amount of the pesticides, particularly foliar pesticides, are intercepted and absorbed by the leaves of the weeds or by the culture itself. Plants contaminated with pesticides may return to the soil during the culture cycle (leaf senescence) or after harvesting (as crop residues). The destination of the pesticide residues in the soil from plant material is both generally ignored and unknown. The pesticide and its degradation products can be released into the soil during the decomposition of the plant, leading to an additional risk of environmental contamination. The greatest consideration when using pesticides (herbicides, insecticides, etc.) is the sensitivity and danger to other non-target species and organisms in the area of application. The adverse effects caused by the indiscriminate use of pesticides, especially herbicides, receive substantial attention because they account for 45% of the world's total pesticide market. In this work, Tukey’s test was used (with a 5% level of probability) to compare soil responses to successive applications of aqueous extracts containing bioherbicides. In general, the existence of bioherbicide residues in soil did not change its properties relative to a control soil. The nutrients evaluated herein did not show a tendency to decrease or increase in concentration during successive applications of the extracts onto the weeds, including possible contact with the soil. The use of bioherbicide did not interfere with the availability of the nutrients or affect the soil fertility characteristics, and it consequently promoted the development of plants throughout the experiment. The persistence of the bioherbicide or its byproducts in soil should not be considered an environmental risk.

scholarly journals Meta-Analysis of Wetland Classification Using Remote Sensing: A Systematic Review of a 40-Year Trend in North America

2020 ◽  
Vol 12 (11) ◽  
pp. 1882 ◽  
Author(s):  
Masoud Mahdianpari ◽  
Jean Elizabeth Granger ◽  
Fariba Mohammadimanesh ◽  
Bahram Salehi ◽  
Brian Brisco ◽  
...  
Keyword(s):  
Remote Sensing ◽  
North America ◽  
Spatial Resolution ◽  
Meta Analysis ◽  
Future Research ◽  
Wetland Classification ◽  
Classification Methods ◽  
Wetland Ecosystems ◽  
Sensing Technology ◽  
Recreational Benefits

North America is covered in 2.5 million km2 of wetlands, which is the remainder of an estimated 56% of wetlands lost since the 1700s. This loss has resulted in a decrease in important habitat and services of great ecological, economic, and recreational benefits to humankind. To better manage these ecosystems, since the 1970s, wetlands in North America have been classified with increasing regularity using remote sensing technology. Since then, optimal methods for wetland classification by numerous researchers have been examined, assessed, modified, and established. Over the past several decades, a large number of studies have investigated the effects of different remote sensing factors, such as data type, spatial resolution, feature selection, classification methods, and other parameters of interest on wetland classification in North America. However, the results of these studies have not yet been synthesized to determine best practices and to establish avenues for future research. This paper reviews the last 40 years of research and development on North American wetland classification through remote sensing methods. A meta-analysis of 157 relevant articles published since 1980 summarizes trends in 23 parameters, including publication, year, study location, application of specific sensors, and classification methods. This paper also examines is the relationship between several remote sensing parameters (e.g., spatial resolution and type of data) and resulting overall accuracies. Finally, this paper discusses the future of remote sensing of wetlands in North America with regard to upcoming technologies and sensors. Given the increasing importance and vulnerability of wetland ecosystems under the climate change influences, this paper aims to provide a comprehensive review in support of the continued, improved, and novel applications of remote sensing for wetland mapping across North America and to provide a fundamental knowledge base for future studies in this field.

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