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The agroecosystem concept
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
Energy flows into an ecosystem as a result of the capture of solar energy by plants, the producers of the system. This energy is stored in the chemical bonds of the biomass that plants produce. Ecosystems vary in their ability to convert solar energy to biomass. We can measure the total amount of energy that plants have brought into the system at a point in time by determining the standing crop or biomass of the plants in the system. We can also measure the rate of the conversion of solar energy to biomass: this is called gross primary productivity, which is usually expressed in terms of kilocalories per square meter per year. When the energy plants use to maintain themselves is subtracted from gross primary productivity, a measure of the ecosystem’s net primary productivity is attained.
Ecological Indicators: Ecosystem Health
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Biological and Ecological Systems, 2020
Felix Müller, Benjamin Burkhard, Marion Kandziora, Claus Schimming, Wilhelm Windhorst
Ascendency: Ascendency is a holistic indicator that is based upon the energy flows in ecological systems and the information associated with the particular network configuration.[57,58] It represents the total system throughput and the flow diversity as a result of the food web structure. The respective network configuration is indicated by the average mutual information. Ascendency is measured by the total system throughput times the average mutual information, providing helpful information on an ecosystem’s energy flow schemes and efficiencies.
Unintended consequences of net zero building from a life cycle perspective
Published in Ming Hu, Net Zero Energy Building, 2019
In the energy flow equation of the natural ecosystem, all systems and individual components depend on solar energy as their primary source, and the productivity of the system depends on the energy captured by the producer, such as a leaf or flower petal. Basically, energy flows in large and connected open systems to produce maximum efficiency. However, in the current net zero building practice, energy flows in a closed loop, which may be extremely large, inefficient, and energy intense. The energy consumed by a building or group of buildings flows from power plants that may be located 1000 from the building site. While the international trade network has made delivering building materials and components globally possible, advanced buildings materials, assemblies, and components are not readily available in all locations. Most new buildings must import those components from far away. For instance, a high-rise building built in Abu Dhabi may have curtainwall glass processed and manufactured in China, stone processed and manufactured in the United States, and mechanical equipment from Germany. The heavy dependency on advanced synthetic building materials imported from outside the local ecosystem does create the possibility to achieve the mathematical net zero goal (end energy use). However, the separation between “onsite” producers and remote “imported” energy results in a much lower sustainability index. Consequently, this will not produce a true net energy flow according to its ecological definition. The same concept has also dominated urban design and planning over the past 20 years. Instead of a self-organized, optimized shape following the energy flow as traditional towns and villages do, modern city developments have heavily relied on planned utility grids. Often, we experience growth without pattern, and growth with sprawl has proved to be very inefficient.
Occurrence and potential harms of organochlorine pesticides (OCPs) in environment and their removal by periphyton
Published in Critical Reviews in Environmental Science and Technology, 2023
Cilai Tang, Zhihao Chen, Yingping Huang, Inna P. Solyanikova, S. Venkata Mohan, Hongfeng Chen, Yonghong Wu
All of them establish a complex ecosystem in a certain order and contribute to the biodiversity and contaminants removal in periphyton (Zang et al., 2018). Moreover, iron, manganese, aluminum-based inorganic minerals are also very important for maintaining the environment stability for periphyton acclimation and growth, as well as for pollutants removal (Wu et al., 2012, 2014). These inorganic minerals could buffer pH for periphyton growth and entrap heavy metals (Ma et al., 2018; Yang et al., 2016) and phosphate (Xu et al., 2020). The main compositions and their functions of periphyton are summarized in Table 2. All of the compositions in periphyton contribute to establishing a multifunctional system, which plays a vital role in energy flow, material circulation, and biogeochemical processes and patterns in natural aquatic ecosystem, as well as contaminants transfer and transformation in aquatic environment (Battin et al., 2016).
Advanced Oxidation Technology (Ozone-catalyzed by Powder Activated Carbon - Portland Cement) for the Degradation of the Meropenem Antibiotic
Published in Ozone: Science & Engineering, 2021
Edison Alexander Agudelo, Santiago Alonso Cardona G.
The WOI parameter can be seen as a complement to the Rct parameter proposed by Elovitz and von Gunten (1999). The Rct factor is suitable for calculating the indirect generation of hydroxyl radicals in natural waters, whereas the WOI is better suited for highly polluted waters. The complementarity of the system proposed in this research (conditioning of pH ≥10 in the oxidation system with ozone and activated carbon) guarantees the robustness and stability of this index since the reactivity values are very similar for different types of wastewater. Like the Rct factor, the WOI must be calculated for each type of wastewater using an experimental design if the system is different from that here proposed. The WOI is based on the first law of thermodynamics because the principle of conservation of matter is considered in the calculation, as are the transformations of mass and energy (flow of electrons) that occur in the system. This gives the index a greater importance and allows it to be extrapolated to other systems.
Distribution and eco-stoichiometry of carbon and nitrogen of the plant-litter-soil continuum in evergreen broad-leaved forest
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Hui Wang, Bing Wang, Xiang Niu, Qingfeng Song, Haonan Bai, Yueqiao Li, Jiadong Luo, Hezhong Chen, Linya Nie, Zhiwei Luo
Ecological chemometrics is a discipline that studies the relationship between multiple chemical elements during ecological processes (Elser et al. 2000). By combining the basic principles of biology, chemistry and physics, measurement of stoichiometric relationships serves as a means to integrate the different scales of the micro- and macro-worlds, providing links between individuals, populations, communities, and ecosystems. This strategy has been successfully used to explore the balance between nutrients, energy, and multiple chemical elements within an ecosystem (Bin, Yongjun, and Wenguang 2010; Dehui and Guangsheng 2005). Eco-chemochemistry unifies the differently scaled components of ecological entities at the elemental level by measuring carbon, nitrogen and phosphorus concentration and calculating their ratios. By doing this, we can better clarify the interactions among ecosystem components and the dynamic balance of chemicals in the process. An ecosystem’s composition, function, and response to environmental changes can also be assessed using stoichiometric relationships. The relative abundance of different chemical components of the ecosystem can control the rate of nutrient cycling and energy flow; thus, we can simply use the ratio of elements to reveal the relationship between carbon and nitrogen cycles in an ecosystem, as well as the constraints and regulations of carbon and nitrogen in the process of mass transfer (Elser et al. 2000; Hessen, Elser, and Sterner 2013; Shaoqiang and Guirui 2008). The carbon and nitrogen cycles both transfer elements between plants, litter, and soil. Using plant-litter-soil as a complete continuum, the carbon and nitrogen concentration and ratios of leaves, litter, and soil in the biome can reveal the interaction between elements and the relationship between material balance and constraints in the chemical process (Shijie, Zhiyou, and Yunxi 2016).