Principles of Ecology PDF

Principles of Ecology Ecology Principles of Ecology Biol-3054  Definition of Ecology  Ecology is the scientific study of the relationships between organisms and their environment  The environment of an organism consists of all those factors and...

Principles of Ecology Ecology Principles of Ecology Biol-3054  Definition of Ecology  Ecology is the scientific study of the relationships between organisms and their environment  The environment of an organism consists of all those factors and phenomena outside the organism that influence it, whether these are physical and chemical (abiotic) or other organisms (biotic).  Ecology examines how living things interact with each other and the physical world around them, providing insights into the complex web of life. 3  Definition of Ecology  At the level of the organism, ecology deals with how individuals are affected by (and how they affect) their environment  At the level of the population, ecology is concerned with the presence or absence of particular species, their abundance or rarity, and with the trends and fluctuations in their numbers  Community ecology then deals with the composition and organization of ecological communities.  Ecology also deals about the pathways of energy and matter between living organisms and non-living 4  Ecology  Ecology is the study of the complex inter-relationships of living organisms with the biosphere, ecosphere, hydrosphere, atmosphere and lithosphere 5  Ecology  Ecology is a vast and complex field that encompasses everything from the intricate interactions between species to the grand, overarching patterns that shape entire ecosystems  Ecology help to understand how the Natural World work  Ecology is a science for everybody – but not an easy science 6  Some ecological questions  Where do organisms live and why?  Why are some organisms common or rare in an area?  What factors determine the diversity, distribution and abundance of a species?  How living organisms survive and live in harsh environments?  How different species coexist?  When does competitions among individuals or species happen?  How climate change affects organismal ecology, population ecology, and community ecology ?  How human activities affect organismal ecology, population ecology, and community ecology?  How diversity, distribution, and abundance of living organism varies in space 7 and time?  Why study ecology?  Curiosity  to know how does the world around us work  to know how we shaped by our surroundings  to know how do different species coexist in an ecosystem  to know how what factors influence population dynamics  to know how do ecosystems respond to environmental changes 8  Why study ecology? Responsibility  To know how do our actions change our environment and live in harmony with nature  To know how do we minimize the detrimental effects of our actions  To know how are the environment shaped by human impacts  To know how do overfishing, habitat destruction, loss of biodiversity, climate change, buildings or other physical structures affect the equilibrium the ecosystems 9  Why study ecology?  Nature provide a guide or information for sustainable life  Ecological systems are models for sustainability  Ecological principles use for natural resource conservation and managements  Sustainable future depends fundamentally on ecological understanding and our ability to predict or produce outcomes under different scenarios 10  Why study ecology?  Basing ecological concepts and principles help to predict what will happen to an organism, a population, a community or an ecosystem under a particular set of circumstances thereby preventing and controlling situations ahead is possible to avoid or alleviate cascade effects 11  Why study ecology?  Ecological ideas and principles helps us understand how the world works  Ecology help us to understand wicked problems 12  Principles of Ecology  The principles of ecology refer to the fundamental concepts and guidelines that govern the interactions between organisms and their environment  In ecology, principles refer to fundamental concepts or rules that govern the interactions, or relationships and dynamics of ecosystems and their components  Ecological principles provide a framework for understanding the dynamics of ecosystems and the interactions between organisms and their environment.. 13  Principles of Ecology  Ecological principles are derived from observations and experiments conducted in natural environments and are essential for understanding how ecosystems function and how they respond to various environmental factors and disturbances  Principles in ecology serve as the foundation for ecological theory and research, guiding scientists in their study of complex ecological systems  Ecological principles help ecologists make predictions about ecological phenomena, design conservation strategies, and assess the impacts of human activities on the environment. 14  Examples of Principles of Ecology  The principles of ecology apply to all facets of the world around us and all aspects of human endeavor  Some key principles in ecology include interdependence, energy flow, nutrient cycling, biodiversity, succession, carrying capacity, adaptation and evolution, habitat and niche, limiting factors, and human impact 15  Examples of Principles of Ecology  Interdependence: organisms within ecosystems are interconnected and depend on each other for survival.  Changes in one species can have ripple effects throughout the ecosystem.  Energy Flow: ecosystems require a constant input of energy, usually from the sun, which is captured by producers (like plants) through photosynthesis and then passed on to consumers through food webs. 16  Examples of Principles of Ecology  Nutrient Cycling: Nutrients such as carbon, nitrogen, and phosphorus are essential for life and are recycled within ecosystems through processes like decomposition and nutrient uptake by plants. .Biodiversity: The variety of life forms within an ecosystem is crucial for its stability and resilience  Higher biodiversity often leads to healthier ecosystems.  Succession: Ecological succession refers to the process of gradual change in the composition of species in an ecosystem over time.  Primary succession occurs in newly formed habitats, while secondary succession occurs after disturbances like fires or logging. 17  Examples of Principles of Ecology  Carrying Capacity: Each ecosystem has a maximum number of organisms it can support, known as its carrying capacity  Factors like resource availability and environmental conditions determine this capacity.  Adaptation and Evolution: Organisms evolve adaptations to better suit their environment, which can influence their survival and reproduction rates over time.  Habitat and Niche: A habitat is the physical environment where an organism lives, while its ecological niche refers to its role within that environment, including its interactions with other organisms and its use of resources. 18  Examples of Principles of Ecology  Limiting Factors: Environmental factors such as temperature, water availability, and food availability can limit the growth of populations within an ecosystem.  Human Impact: Human activities, such as deforestation, pollution, and climate change, can have significant impacts on ecosystems and biodiversity, often disrupting natural processes and leading to habitat loss and species decline. 19  Branches of Ecology Organismal Ecology Population Ecology Community Ecology 20  Branches of Ecology Organismal ecology Population ecology Community ecology  focuses on the  studies the dynamics  explores the adaptations, and interactions of relationships between behaviors, and groups of the same different species within relationships of species, such as an ecosystem, individual organisms birth rates, death within their rates, and migration including competition, environment patterns predation, and  examines how  helps understand symbiosis factors like how populations  examines how these temperature, water grow, decline, and biotic interactions availability, and influence each other shape the structure competition influence over time. the survival and and function of entire reproduction of communities. species. 21  Methods in Ecology 1 Observation Carefully watching and recording the behaviors and interactions of organisms in their natural habitats. 2 Experimentation Designing controlled studies to test hypotheses and understand cause-and-effect relationships. 3 Modeling and stimulation Using mathematical and computational tools to simulate and predict ecological patterns and processes. 4 Sampling Collecting and analyzing data on populations, communities, and environmental factors. 22  Methods in Ecology 1 Field Observation 2 Experimentation Ecologists often conduct direct Controlled experiments are used to observations of organisms in their test hypotheses and establish cause- natural habitats, recording data on and-effect relationships between behaviors, populations, and ecological factors, such as the environmental conditions. impact of a new predator or the effects of climate change. 3 Modeling and Simulation 4 Monitoring and Data Collection Sophisticated computer models and simulations are employed to predict Long-term monitoring of the dynamics of complex ecological environmental parameters, species systems and test the potential populations, and ecosystem outcomes of various scenarios. processes provides crucial data for understanding ecological trends and 23 patterns over time.  Environmental factors In ecology, environmental factors refer to the various external conditions and influences that affect the life processes, behaviors, and interactions of organisms within an ecosystem  influence the presence and abundance of species are determined by the suitability of abiotic and biotic conditions  regulate population sizes through birth rates, death rates, immigration, and emigration  Influence The composition and interactions of species within a community are shaped by the availability of resources and the presence of predators, competitors, and mutualists  influence the flow of energy and cycling of nutrients are driven by environmental factors. Primary productivity, decomposition, and trophic interactions are all affected  Environmental factors act as selective pressures that drive natural selection, leading to adaptations and speciation over time 24  Environmental Factors Abiotic Non-living physical and chemical components of the environment, such as temperature, light, and soil composition. Biotic Living organisms, including plants, animals, and microbes, and their interactions within an ecosystem. Interactions The complex relationships between abiotic and biotic factors that shape the environment. 25  Environmental Factors: abiotic Factors  the non-living components of the environment  the physical, chemical, and geological components of the environment, such as light, temperature, precipitation, soil composition, and atmospheric conditions  Play a crucial role in shaping the distribution, abundance, and adaptations of living organisms 26  Environmental Factors: biotic Factors  the living components of the environment  including other organisms, such as plants, animals, fungi, and microbes  influence each other through various interactions, such as competition, predation, symbiosis, and resource sharing. 27  Environmental Factors: interactions  Abiotic and biotic factors are closely interconnected  The interplay between abiotic and biotic factors is essential for the proper functioning of ecosystems.  Changes in one factor can have cascading effects on the other, leading to complex and dynamic relationships that ecologists strive to understand  Understanding these complex interactions is essential for understanding the functioning of ecosystems and predicting their responses to environmental changes  The dynamic interplay between biotic and abiotic factors shapes the composition, the structure and functions of ecosystems over time  The dynamic interplay between biotic and abiotic includes processes such as nutrient cycling, energy flow, and the maintenance of biodiversity, which are crucial for the sustainability of life on Earth 28  Examples of biotic and abiotic Factors Water Sunlight Plants Predation An abiotic factor A biotic factor that A biotic factor that is essential An abiotic factor serves as the where one for the survival of that provides primary producers organism (the all living energy for in many predator) organisms and photosynthesis ecosystems, consumes another shapes the and affects the providing food and organism (the physical temperature and shelter for other prey), influencing environment. climate of an organisms. the population ecosystem. dynamics of both species. 29  Classification of environmental factors Climatic Edaphic Factors related to the climate, such Factors related to the soil, including as temperature, precipitation, and its composition, structure, and atmospheric conditions. nutrient content. Topographic Biotic Factors related to the physical Factors related to the living features of the landscape, such as components of the environment, elevation, slope, and aspect. including competition, predation, and symbiotic relationships. 30  Classification of environmental factors Climatic factors Edaphic factors These include temperature, precipitation, Edaphic factors are related to the physical humidity, wind, and solar radiation, which and chemical properties of the soil, such as are primarily influenced by the Earth's soil texture, pH, nutrient availability, and geographic location, altitude, and latitude. moisture content. These factors directly They play a crucial role in determining the impact the growth and distribution of plants distribution and adaptation of organisms. and the organisms that depend on them. Topographic factors Biotic factors Topographic factors, such as elevation, Biotic factors include the interactions slope, and aspect, can influence the between living organisms, such as microclimate, water availability, and soil competition, predation, symbiosis, and characteristics of a particular area, thereby resource partitioning. These factors shape affecting the types of organisms that can the structure and dynamics of ecological thrive there. communities. 31 Classification of environmental factors: density-dependent factors  Environmental factors whose effects on organisms depend on population size or density, such as competition, predation, and disease.  As the population density increases, the impact of these factors on individual organisms also increases, often leading to changes in growth, reproduction, and survival rates  Examples include competition for resources, predation, and the spread of diseases  Understanding density-dependent factors is critical for conservation efforts, wildlife management, and ecological research, as they provide insight into the dynamics of population growth and the health of ecosystems  32  Density-dependent factors  Competition for resources  Food: As the population grows, the demand for food increases. Limited food resources can lead to malnutrition, reduced reproductive success, and higher mortality rates.  Water: Similar to food, water becomes scarcer as more individuals consume it, leading to dehydration and competition.  Space: Limited space for living and breeding can result in overcrowding, which can stress individuals and reduce the carrying capacity of the environment  33  Density-dependent factors  Predation  As prey populations grow, they become more visible and easier for predators to find. Predators may increase in number or hunting efficiency, which in turn can reduce the prey population  Disease and Parasites  High population density facilitates the spread of infectious diseases and parasites  Close proximity of individuals increases the transmission rate of pathogens, leading to higher mortality rates. 34  Density-dependent factors  Waste Accumulation:  Increased population density can lead to the accumulation of waste products. This can pollute the environment and contribute to health problems, which can decrease population growth.  Behavioral Changes:  Social stress and aggressive interactions can increase in crowded populations.These behavioral changes can lead to lower reproductive rates and higher mortality rates 35  Mechanisms of Density-Dependent Regulation  Negative Feedback: density-dependent factors often create a negative feedback loop that helps regulate population size. For example, as food becomes scarce, individuals may have fewer offspring or die off, reducing the population size and eventually restoring balance.  Carrying Capacity: the environment's carrying capacity is the maximum population size that it can sustainably support  Density-dependent factors are crucial in keeping the population near this carrying capacity. 36  Importance of Density-Dependent factors in Ecology n  Population Stability: Density-dependent factors are essential for maintaining population stability and preventing uncontrolled population growth, which could lead to resource depletion and environmental degradation.  Natural Selection: These factors contribute to natural selection by favoring individuals that can survive and reproduce under high-density conditions, leading to evolutionary adaptations over time 37 Classification of environmental factors: density-Independent factors  Environmental factors whose effects on organisms are not influenced by population size or density, such as weather, natural disasters, and some human activities  Density-independent factors are environmental factors that affect organisms regardless of their population density.  The interplay between density-dependent and density-independent factors is crucial in shaping the dynamics of ecological systems  Understanding how these factors influence population growth, community structure, and ecosystem functioning is a key focus of ecological research  Example temperature, precipitation, and natural disasters, which can profoundly impact the survival and distribution of species without being influenced by their population size 38  Periodicity in Ecology  In ecology, periodicity refers to the regular, cyclical patterns observed in various ecological processes and phenomena  Periodicity occurs at predictable intervals and can be influenced by a variety of factors, both biotic (living) and abiotic (non-living)  Periodicity is significant in ecology as it helps in understanding the timing and frequency of biological events and their interactions with the environment  Understanding periodicity in ecology is crucial for conservation efforts, agricultural planning, and predicting the impacts of climate change 39  Periodicity in Ecology: Seasonal Changes:  Many ecological processes follow a seasonal pattern.  Cyclical variations in temperature, precipitation, and other environmental factors that drive the phenology and life cycles of organisms  Seasonal variations in temperature, precipitation, and daylight hours drive periodic changes in the behavior, physiology, and life cycles of organisms.  Seasonal patterns are essential for the synchronization of important events, such as migration, hibernation, and plant flowering  For example, plant flowering and animal breeding often occur at specific times of the year when conditions are most favorable 40  Periodicity in Ecology: circadian rhythms  Internal biological clocks that synchronize an organism's activities with the 24- hour day-night cycle  the 24-hour cycles of biological activity that are influenced by the Earth's rotation and the presence or absence of sunlight  24-hour cycles in the physiological processes of living organisms, influenced by external cues like light and temperature  The circadian rhythms affect the timing of various processes, such as feeding, reproduction, and physiological functions, in many organisms.  Examples include sleep-wake cycles in animals and photosynthesis patterns in 41 plants  Periodicity in Ecology: population growth cycles  Some species exhibit regular fluctuations in population size over time.  For instance, populations of certain rodents and insects may boom and bust in predictable cycles due to factors like food availability and predation pressure 42  Periodicity in Ecology  Phenological events: These are seasonal events in the life cycle of plants and animals, such as migration, hibernation, leaf-out, and leaf-fall  They are often triggered by environmental cues such as temperature and daylight length 43