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The plant: nutrition, growth, and response to the environment
Published in Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz, Agroecology, 2023
Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz
Autecological study of plants begins by dividing the environment in which plants live into individual factors. This is not as simple as it may sound because factors interact with and modify each other and have different components. Making up the environment in which plants live are non-living, or abiotic factors, and living, or biotic factors. (In the chapters that follow, we consider abiotic factors first.) In the realm of the abiotic, many factors can be examined from two perspectives: their origin in the physical environment and the way in which they directly impact plants. Consider water, for example: plants take up water through their leaves and through their roots, and their ability to do so is determined by the amount of water in the air and in the soil, but any water in the air or soil comes from precipitation, either directly or, in the case of irrigated systems, indirectly. Thus, when we discuss the factor relating to plants’ use of water, we can use the terms precipitation or rainfall, or we can locate the factor in the immediate environment of the plant and use the term moisture availability. The terminology for other factors is more straightforward. The abiotic factors we consider in this section are as follows: light, temperature, precipitation or moisture availability, wind, and soil. Soil, as presented in Chapter 8, is a complex mixture of abiotic and biotic factors.
Microbial Degradation of Pesticides in the Environment
Published in Ram Chandra, R.C. Sobti, Microbes for Sustainable Development and Bioremediation, 2019
Prashant S. Phale, Kamini Gautam, Amrita Sharma
The fate of pesticides in the environment depends not only on the presence of the microbial population but also on various abiotic and biotic parameters. Therefore, understanding the factors and mechanisms that affect biodegradation is of great significance from the perspective of efficient and complete removal of pesticides. Abiotic factors include soil type, temperature, pH, oxygen availability, moisture content, etc. The effect of soil pH on pesticide degradation depends on whether a pesticide is susceptible to acid or alkaline-catalyzed hydrolysis (Aislabie and Lloyd-Jones 1995). Temperature is considered as one of the key factors that affect the adsorption of pesticide by altering its solubility and hydrolysis (Racke et al. 1997). The biotic factor includes the substrate bioavailability, metabolic capacity, diversity, metabolic efficiency, etc. In soil, pesticides are reported to bind tightly to soil organic matter that reduces its bioavailability for degradation. Also in nature, microbes have inherent characters like the specificity for utilization of substrate that affects the substrate degradation. Moreover, the optimum growth conditions required for microbes are unpredictable, as the vitality of them is important for efficient function (Srivastava et al. 2014). The availability of substrate for the microbes is limited when the pesticides are less/not soluble in water. This can be overcome by pretreatment of contaminated soil with surfactants that enhance the pesticide solubility (Zhu and Aitken 2010). The concentration of pesticides at the toxicity level is one of the factors that also affect the bioremediation process as it can kill the microbes (Abdel-Shafy and Mansour 2016).
The Role of Plasma Membrane Proteins in Tolerance of Dehydration in the Plant Cell
Published in Hasanuzzaman Mirza, Nahar Kamrun, Fujita Masayuki, Oku Hirosuke, Tofazzal M. Islam, Approaches for Enhancing Abiotic Stress Tolerance in Plants, 2019
Pragya Barua, Dipak Gayen, Nilesh Vikram Land, Subhra Chakraborty, Niranjan Chakraborty
Abiotic factors include non-living physical and chemical environmental components, alteration of which affects the living organism and the ecosystem. Since plants spend their entire lifespan in a fixed niche, they have to have a robust defense mechanism that enables them to survive and grow under changing conditions. Deviation towards either extreme (high or low) from the optimum levels of abiotic factors such as light, temperature, and salinity, among others, trigger stress responses at the cellular level.
LED light use for the improvement of wastewater treatment in the hydroponic system
Published in Environmental Technology, 2020
Aleksandra Bawiec, Katarzyna Pawęska, Krzysztof Pulikowski
Analysis of impact of insolation on the wastewater treatment conducted by Bawiec et al. 2018 [7] confirmed that in the moderate climate conditions, the use of the hydroponic system as the III° of wastewater treatment may be problematic, due to the insufficient amount of the insolation reaching the Earth's surface, which would ensure maintenance of high efficiency of nutrient removal by plants throughout the year. Research has shown that the greatest effect on the effectiveness of nitrate removal in the hydroponic treatment plant has the value of insolation in the 10-day period before making the analyses. The sum of insolation that is necessary to obtain the effect of nitrates removal from the wastewater treated in the hydroponic lagoon was estimated at 48.6 h. Light next to the water, carbon dioxide, the right temperature and nutrients is one of the most important environmental abiotic factors conditioning the proper growth of plants [8–10]. It is also one of the factors (next to the availability of CO2, nitrogen and phosphorus concentration, temperature and hydration), which effects on plants can be optimized through activities undertaken by people [11].
Implications of environmental conditions for health status and biomechanics of freshwater macrophytes in hydraulic laboratories
Published in Journal of Ecohydraulics, 2020
Davide Vettori, Stephen P. Rice
Bornette and Puijalon (2011) report the following abiotic factors as the most significant causes of stress in freshwater macrophytes: light, temperature, characteristics of water, characteristics of substrate, and water movements. The present study focuses on the first three factors. When the water column is rich in nutrients, plants need the substrate only for anchoring. Water movement influences plant reconfiguration and morphological characteristics, and might affect plant biomechanics too. However, the effects of water movement on plant health status and biomechanics are likely to be significant at temporal scales larger than the temporal scale used in the current study, therefore they were not investigated here. Nevertheless, we expect that the flow conditions plants are exposed to in flume facilities may have additional effects on plant physiology or biomechanics.
The fate and enhanced removal of polycyclic aromatic hydrocarbons in wastewater and sludge treatment system: A review
Published in Critical Reviews in Environmental Science and Technology, 2019
Xiaoyang Zhang, Tong Yu, Xu Li, Junqin Yao, Weiguo Liu, Shunli Chang, Yinguang Chen
Usually, wastewater treatment plant is designed to remove suspended solids, organic matters and inorganic nutrients, such as phosphorus and nitrogen (Margot, Rossi, Barry, & Holliger, 2015). It mainly includes primary and secondary treatments, and tertiary treatments are also conducted in some advanced WWTPs. The main mechanisms for PAHs removal in these processes include sorption onto suspended solids and sludge, biotransformation (biodegradation), and volatilization. The abiotic degradation, such as photolysis and hydrolysis, may occur naturally (Margot et al., 2015). However, it was reported that only 5–15% of the target four PAHs was eliminated by abiotic degradation (Li, Wong, & Tam, 2010), suggesting that it could be ignored compared with their significant removal in WWTPs.