Lesson 1 (Introduction) PDF

MODULE 1: PEOPLE'S AND EARTH'S Habitat function: ECOSYSTEMS (GEE2) Natural ecosystems provide refuge and a reproduction habitat to wild plants and animals and INTROD...

MODULE 1: PEOPLE'S AND EARTH'S Habitat function: ECOSYSTEMS (GEE2) Natural ecosystems provide refuge and a reproduction habitat to wild plants and animals and INTRODUCTION TO ECOLOGY thereby contribute to the (in situ) conservation of Biology - the study of living organisms, divided into biological and genetic diversity and the many specialized fields that cover their morphology, evolutionary process. physiology, anatomy, behavior, origin, and Production function: distribution. Photosynthesis and nutrient uptake by autotrophs converts energy, carbon dioxide, water Ecology - Ecology is the study of how living and nutrients into a wide variety of carbohydrate organisms interact with one another and with their structures which are then used by secondary environment. producers to create an even larger variety of living Population Ecology - Population ecology is the biomass. This broad diversity in carbohydrate study of how groups within a species interact with structures provides many ecosystem goods for their environment. human consumption, ranging from food and raw materials to energy resources and genetic material. Community Ecology - Community ecology is the study of how groups of living things interact with Informational Functions: each other, within a specific geographic area. Since most of human evolution took place within the context of an undomesticated habitat, Conservation Ecology - deals with the preservation natural ecosystems contribute to the maintenance of and management of biodiversity and natural human health by providing opportunities for resources reflection, spiritual enrichment, cognitive Ecosystem Ecology - ecosystem ecology is the study development, recreation and aesthetic experience. of how energy and materials enter, move through, ECOSYSTEM COMPONENTS and leave ecosystems. 1. Biotic Factors - all living things that affects WHAT IS ECOLOGY? an organism. Ecology is the study of interactions that 2. Abiotic Factors - non-living are the take place between organisms and their environment physical and chemical characteristics of an environment ECOLOGY is the study of the interaction among organisms and between organism (biotic) Autotrophs - (producer) where they can make their and their physical environment. food “oikos” meaning “home”, logy meaning “the study Heterotrophs - (consumer) that depend on other of” organisms as their source of food - Ernst Haeckel HERBIVORES - are heterotrophs that feed on only Levels of Ecological Organization plants 1. Organism CARNIVORES - Heterotrophs that eats only meat 2. Population 3. Community OMNIVORES - are heterotrophs that feed on both 4. Ecosystem plants and animals 5. Biome SCAVENGERS - are heterotrophs that feed on 6. Biosphere animals that have already died ECOSYSTEM FUNCTIONS DECOMPOSERS - break down the complex Regulatory function: compounds of dead and decaying plants and animals This group of functions relates to the into simpler molecules that can be more easily capacity of natural and semi-natural ecosystems to absorbed regulate essential ecological processes and life ABIOTIC COMPONETS - such as water, light, support systems through bio-geochemical cycles soil, temperature, ph can be a limiting factor for and other biospheric processes. In addition to certain organisms. maintaining the ecosystem (and biosphere health), these regulatory functions provide many services that have direct and indirect benefits to humans (i.e., clean air, water and soil, and biological control services). ENERGY FLOW CONCEPT MAP TROPHIC LEVELS Each organism in a food chain represents a feeding step, or trophic level, in the passage of energy and materials A food chain represents only one possible route for the transfer of matter and energy through an ecosystem. FOOD WEBS A food web shows all the possible feeding ECOLOGICAL PYRAMID relationships at each trophic level in a community The concept of energy flow in ecosystem is Energy Transfer Through Trophic Levels one of the cornerstones of Ecology. The first Law of Thermodynamics state that “energy is neither created nor destroyed but is transformed from one state to another and that the sum total can be accounted for”. The second Law of Thermodynamics states that “ during each energy transfer from one state to another, some of it is transformed into an unusable form, heat”. -R.L. Linderman Food Web in an Antarctic Ecosystem Nutrient Cycling in Ecosystem In a self-sustaining ecosystem, elements or materials must be cycled among living organism and abiotic environment, this complex cycle is referred to as BIOGEOCHEMICAL CYCLE. FOOD CHAIN 1. A food chain is a simple model that scientists use to show how matter and energy move through an ecosystem. 2. In a food chain, nutrients and energy move from autotrophs to heterotrophs and, eventually, to decomposers 3. A food chain is drawn using arrows to Ecological Food Pyramid indicate the direction in which energy is transferred from one organism to the next- An ecological pyramid can show how energy flows uses 3 to 5 links through an ecosystem The base of the ecological pyramid represents the Food Chain in an Antarctic Ecosystem autotrophs, or first trophic level. Higher trophic levels are layered on top of one another. Trophic level Pyramid CYCLES OF LIFE The Water Cycle The Nitrogen Cycle Steps of the Water Cycle Nitrogen is used by living organisms to produce a number of complex organic molecules 1. Evaporation like amino acids, proteins, and nucleic acids. 2. Condensation 3. Transpiration The amount of nitrogen found in the 4. Precipitation atmosphere, where it exists as a gas (mainly N2), plays an important role for life. The hydrologic, or water, cycle is the circular pathway of water on Earth. Organisms all The nitrogen cycle the nitrogen cycle have bodies made mostly of water. mostly takes Place underground. Some bacteria convert gaseous nitrogen into ammonia through a process called nitrogen fixation. Some nitrogen-fixing bacteria live in nodules on the roots of plants; others live freely in the soil. Oxygen Cycle Indirectly through an ecosystem by the cycling of other nutrients. The Carbon Cycle The carbon cycle is the process through which carbon is cycled through the air, ground, plants, animals, and fossil fuels. Large amounts of carbon exist in the atmosphere as carbon dioxide (CO2). Carbon dioxide is cycled by green plants during the process known as photosynthesis to make organic molecules (glucose, which is food). Carbon is emitted by the burning of fossil fuels. The phosphorus cycle takes place at and below Some carbon is stored for long periods of ground level. time in areas called carbon sinks.  Phosphate is released by the weathering of temperate climates. In India, they are found rocks. Phosphorus moves through the food web and mainly in the high Himalayas. The rest of returns to the soil during decomposition. Phosphorus India’s grasslands are mainly composed of leaches into ground water from the soil and is locked steppes and savannas. in sediments. Both mining and agriculture add Major difference between steppes phosphorus into the environment. and savannas is that all the forage in the steppe is provided only during the brief wet TYPES OF ECOSYSTEM season whereas in the savannas forage is TERRESTRIAL ECOSYSTEM - The terrestrial largely from grasses that not only grow environment is based on land and consists of during the wet season but also from the biomes, such as grasslands, one of several kinds of smaller amount of regrowth in the dry forests, savannas, or deserts. season.  Tundra - Tundra means a “barren land”. AQUATIC ECOSYSTEM Tundra ecosystems are treeless regions  Freshwater environment - The where environmental conditions are very freshwater environment can be further severe. subdivided between standing-water Characteristics: habitats (lakes, reservoirs) and running- Harsh climatic conditions (cold and water habitats (streams, rivers). windy): Winters are long and very severe;  Oceanic marine environment - The summers are cool and brief. oceanic marine environment is Precipitation: Scanty rainfall, precipitation characterized by saltwater and may be is mainly in the form of snow. divided broadly into the shallow waters of Soil: Permafrost or soil that remains frozen the continental shelf composing the neritic all year round and is also scarce of zone nutrients. Low biotic diversity OTHER TYPES OF RELATIONSHIP  Rainforest Ecosystem - A forest ecosystem is a dynamic complex of SYMBIOSIS different kinds of biotic components and The relationship in which there is a close their abiotic environment interacting as a and permanent association between organisms of functional unit, where trees are a key different species is called symbiosis. Symbiosis component of this ecosystem. means living together. The forest ecosystems have been classified into three major categories: 3 Types of Symbiosis coniferous forest, temperate forest and MUTALISM tropical forest. All these forest biomes are is a symbiotic relationship in which both generally arranged on a gradient from north species benefit to south latitude or from high to lower altitude. COMMENSALISM  Desert Ecosystem - is a region of scanty is a symbiotic relationship in which one rainfall supporting a community of species benefits and the other species is neither distinctive plants and animals specially harmed nor benefited. adapted to the harsh environment. Deserts are formed in regions with less than 25 cm PARASITISM of annual rainfall.  Grassland Ecosystem - is an area where is a symbiotic relationship in which a the vegetation is dominated by continuous member of one species derives benefit at the cover of grasses and herbaceous (non- expense of another species (the host) woody) plants. It accounts for between 20 and 40% of the world’s land area. The grasslands are found where rainfall is about 25-75 cm per year, not enough to support a forest, but more than that of a true desert. Typical grasslands are vegetation formations that are generally found in