The paper asks, if ponds located in agroecosystems can be prevented from tipping over by variation in combinations of fertilizers and pesticides. Through a simulation in NetLogo, an agent-based programmable modeling environment, the interplay of two pesticides (Cypermethrin and Malathion) and a fertilizer (Nitrogen + Phosphate) and their effect on the aquatic productivity is observed.
The model depicts an agroecosystem with three separate fields and two ponds. The model is simplified by assuming consistent environmental conditions and narrowing down the pond population to one zooplankton species and one phytoplankton species (Chlorella vulgaris). Through variation of variables different scenarios are generated.
The research revealed that input of pesticides – even without fertilizers which are known for supporting phytoplankton growth – results in eutrophication through decreasing zooplankton population and therefore blooming phytoplankton population. The original contribution of the simulation is in revealing that beyond the amount of chemical substances used in farming, the variation of input is also to consider, since certain ones may have greater negative effects than assumed so far.
Table of Contents
1. Introduction
2. Material and Methods
2.1 Purpose
2.2 Entities, state variables and scales
2.3 Process overview and scheduling
2.4 Design concepts
2.5 Initialization
2.6 Input data
3. Results
4. Discussion
5. List of References
Research Objectives and Key Topics
This paper investigates whether ponds in agroecosystems can be protected from eutrophication and ecological collapse by varying the combinations of fertilizers and pesticides applied in surrounding fields. Using an agent-based simulation model, the study examines how specific chemical inputs alter the balance between zooplankton and phytoplankton populations in aquatic habitats.
- Agent-based modeling (NetLogo 6.0.2) of agroecosystem dynamics.
- Interaction effects of specific pesticides (Cypermethrin and Malathion) and fertilizers (Nitrogen + Phosphate).
- Impact of chemical runoff on aquatic trophic levels and oxygen saturation.
- Comparative analysis of different application scenarios regarding water health.
- Assessment of potential conservation measures based on variable input management.
Excerpt from the Book
1. INTRODUCTION
The use of synthetic fertilizers and pesticides is increasing in modern agriculture, contaminating whole agroecosystems. Pesticides that are applied to protect crop from weed and pest insects also expose non-target organisms to higher risk. Since most of the pesticides are persistent in the environment, surrounding flora depauperates and several faunal species are deprived of their food resources. (Umweltbundesamt, 2017) (Schachtschabel et. al, 2010, S.114). Only a small amount of applied pesticides has the desired effect and hits the target. The rest gets into the soil and air and, through run-off, into nearby water bodies and negatively affect their health, structure and function. Thus, it can be said that pesticides are, together with excessively applied fertilizers, the main pollutants of aquatic ecosystems (Hedge et. al, 2014, S. 435).
Pesticide decline the zooplankton population, which results in the bloom of phytoplankton populations, such as algae. Fertilizers in turn, enhance the phytoplankton productivity. Thus, both agrochemicals lead to increasing population of phytoplankton, which is a main cause of eutrophication (Hedge et. al, 2014, S. 435) This phenomenon forms the basis for this research.
Summary of Chapters
1. Introduction: Outlines the environmental challenges of agricultural chemical runoff and sets the foundation for the simulation study.
2. Material and Methods: Details the design of the agent-based model, including agents, spatial units, scheduling, and the variables used for initialization.
3. Results: Presents the data from two simulation scenarios, comparing pond health indicators like phytoplankton growth and oxygen saturation.
4. Discussion: Evaluates the simulation results against established literature and addresses the limitations and potential extensions of the model.
5. List of References: Provides the academic literature and data sources utilized for this study.
Keywords
Agent-based modelling, Agroecosystems, Eutrophication, Pesticides, Fertilizers, Zooplankton, Phytoplankton, Aquatic productivity, NetLogo, Simulation, Water quality, Trophic levels, Environmental impact, Chemical runoff, Biodiversity.
Frequently Asked Questions
What is the core focus of this research paper?
The paper focuses on the impacts of pesticide and fertilizer combinations on the aquatic health of ponds within agroecosystems, specifically looking at the phenomenon of eutrophication.
What are the primary thematic areas covered?
The main themes include agricultural pollution, aquatic ecology, predator-prey dynamics between zoo- and phytoplankton, and the use of computational simulation to predict ecological outcomes.
What is the primary goal of the study?
The goal is to determine if varying the combinations of chemical inputs can prevent ponds from "tipping over" into a eutrophic state through the observation of a simulated environment.
Which scientific method is employed?
The research employs agent-based modeling (ABM) using NetLogo 6.0.2 to simulate an agroecosystem comprising three fields and two ponds.
What topics are discussed in the main body of the work?
The main body details the methodology, including agent behavior and initialization, presents the results of two different pesticide/fertilizer application scenarios, and discusses the implications of these findings.
Which keywords best characterize this work?
Key terms include agent-based modelling, eutrophication, pesticides, fertilizers, zooplankton, and phytoplankton.
How does the model simulate the impact of chemicals on zooplankton?
The model simulates impact by reducing the energy levels of zooplankton individuals upon encounter with pesticides, ultimately leading to death if the exposure is sustained.
What does the simulation reveal about pesticide-only scenarios?
The research reveals that even in the absence of fertilizers, pesticide input alone can lead to eutrophication by drastically decreasing the zooplankton population, which subsequently causes a bloom in phytoplankton.
What limitation is noted regarding the model's representation of chemical diffusion?
The model assumes 100 percent of input chemicals diffuse into the soil, which ignores real-world factors such as distribution into air and groundwater or varying runoff rates.
- Citar trabajo
- Melanie Bayo (Autor), 2018, Agent-Based-Modelling. Pond eutrophication in agroecosystems and the influence of combinations of pesticides and fertilizers on aquatic productivity, Múnich, GRIN Verlag, https://www.grin.com/document/468575
