Two Major Components of Ecosystem 1. Abiotic • Consists of nonliving chemical and physical components such as water, air, nutrients in the soil or water and solar energy. • Physical and chemical factors that influence living organisms in land (terrestrial) ecosystems and aquatic life zones Terrestrial Ecosystem Aquatic Life Zone 1. Sunlight 1. Light penetration 2. Temperature 2. Water current 3. Precipitation 3. Dissolved nutrient concentrations4. 4. Wind (especially N and P) 5. Latitude 4. Suspended solids (distance from equator) 5. Salinity(the amounts of various 6. Altitude inorganic minerals or salts dissolved (distance above sea level) in a given volume of water) 7. Fire frequency 8. Soil 2. Biotic • Made up of biological components consisting of living and dead plants, animals and microorganisms • The Major Biological Components of Ecosystem a. Producers (Autotrophs)(self-feeders) o Make their own food from compounds that are obtained from their environment. o Are the source of all food in an ecosystem o On land most producers are green plants. o In freshwater and marine ecosystems, algae and plants are the major producers near shorelines o In open water, the dominant producers are phytoplankton (most of them microscopic) that float or drift in the water. o Most producers capture sunlight to make carbohydrates (such as glucose) by photosynthesis o A few producers, mostly specialized bacteria, can convert simple compounds from their environment into
more complex nutrient compounds without sunlight a process called chemosynthesis b. Consumers (Heterotrophs) (“other feeders”) o Get their energy and nutrients by feeding on other organisms or their remains. a. Primary consumers = are those that eat producers (plants) as a source of food also known as herbivores. b. Secondary consumers or carnivores = eat other animals c. Omnivores = have mixed diet that include both plants and animals d. Decomposer = Mostly certain types of bacteria and fungi are specialized consumers that recycle organic matter in ecosystems =They do this by breaking down (biodegrading) dead organic material to get nutrients and releasing the resulting simpler inorganic compounds into the soil and water, where they can be taken up as nutrients by producers Detritus • Consisting of parts of dead organisms and cast-off fragments and wastes of living organisms.KINDS OF ORGANISM INTERACTIONS 1. Predation = situation in w/c an organism of one species (the predator) captures and feeds on parts or all of an organism of another species (the prey) 2. Competition = a kind of interaction in w/c two organisms strive to obtain the same limited resource and in the process both organisms are harmed to some extent. a. Intraspecific competition – competition w/c is between members of the same species b. Interspecific competition – competition among organisms of different species 3. Symbiotic relationships a. Symbiosis – is a close, long lasting, physical relationship between two different species of organisms.
– the two organisms are usually in physical contact and at least one of the organisms derives some sort of benefit from this contact b. Parasitism – is a relationship in w/c one organism, known as the parasite, lives in or on another organism, known as the host, from w/c it derives nourishment. 1), Ectoparasite – those that live on the surface of their host 2). Endoparasite – those that live inside the bodies of their hosts c. Commensalism – relationship in w/c one organism benefits while the other is not affected. Ex Remora fish attached to shark d. Mutualism – symbiotic relationships that are actually beneficial to both species of organisms involved Module 2 ABIOTIC COMPONENTS OF THE ENVIRONMENTAbiotic components The physical & chemical factors that influence the various metabolic & physiological processes of the organisms as well as regulate their functions The major abiotic factors are climatic, edaphic & topographic factors These factors are classified as resources and conditions A. Resources – are those factors that can be consumed or directly utilized by organisms like nitrogen, phosphorus and potassium . B. Environmental conditions – Are factors that are not directly utilized by the organisms but affect the growth and survival of the organisms. – However, these factors can also be changed or affected by the organisms such as temperature or salinity 1. Climatic Factors
Climate – is the result of interplay of the seasonal factors like temperature, humidity, precipitation and light conditions in a particular area – it places the greatest constraint on the organisms and it influences the weather condition in a local area. – a region’s general pattern of atmospheric or weather conditions over a long period – is the long term average pattern of weather – it determines the availability of heat and water, influences the amount of solar radiation that can be captured by the plants Weather – is a temporary condition of the atmospheres, a combinationof temperature, pressure, humidity, precipitation, sunshine winddirection and speed, cloudiness and other atmospheric conditions atspecific time and placeClimate and weather are directly affected by energy and physicalprocess in the environment is also influenced by the activities of livingorganisms. a. Solar radiations Is the amount of light intercepted by the earth that causes thermal patterns. Energy that travels through space in the form of waves of particles. The solar radiation travels through the space as waves describe as wavelength, The amount of solar radiation varies over the earth surface depending on the latitude and altitude The higher the latitude the lesser solar radiation is intercepted because the radiations are spread over larger
area. This explains why temperature is higher in tropic than at the poles. The seasonality of solar radiation, temperature and day length also increases with latitude. The Artic and Antartic region have varied daylengths from continuous daytime during summer solstice. The equatorial region receives the most radiation and equal occurrence of day and night. The pattern controls the mean annual temperature around the globe The rotation of the earth and its movements around the sun generates the wind and ocean currents. These movements influence the distribution of rainfall.b. Temperature Is the degree of heat that is natural to the body of living things. It has pervasive influence on life on earth by affecting the rates of photosynthesis and stored energy in plants It also influences the amount of moisture and the need for it by the organisms because it takes part in the chemical reactions in all living organisms. Variation in the environmental temperature affects the distribution and abundance of organisms. Temperature varies depending on the latitude, altitude, season, and continents, microclimatic variation and depth variation. Air temperature decreases with altitude, the higher the altitude the lower the temperature, decreasing by 0.6°C every 100 meters. It then influences the growth of plants; the higher the altitude the greater is the pressure thus plants become stunted. Temperature also affects the function of plants and cold- blooded animals by controlling the rate of their metabolism. Plants can tolerate extreme cold by frost hardening its body part but the response is for short period only.
Prolonged exposure to extreme conditions like heat and cold could affect their physiological processes and may cause death. Plants living in desert have thick barks and small leaves to reduce the loss of water. Some plants were able to survive in very low temperature by their creeping habits to avoid too much exposure to extreme low temperature. Animals on the other hand can maintain a fairly constant internal body temperature by using their behavioral and physiological means but they are still categorized into three major groups; a. Poikilothermic (variable body temperature)– have variable body temperature influenced mainly by the existing temperature. Ex Sea lamprey b. Homeothermic (constant body temperature) – are organisms that have body temperature that are independent of the environment Ex birds, mammals c. Heterotherms – organisms that can switch to endotherms (source of their body heat is internal) and homoethermic. During environmental extremes, some animals may enter a state of torpor (state of mental and motor inactivity with partial or total insensibility) by reducing their metabolism, heartbeat and respiration to reduce their energy cost and stay warm or cool. Hibernation – seasonal torpor over winter. Condition especially mammals, of passing the winter in a torpid state in w/c the body temperature drops nearly to freezing and the metabolism drops close to zero. - Amphibians move in and out the water while desert animals burrow their bodies to the ground to seek shade. - Some desert animals also use hyperthermia to reduce the difference between body and environmental temperaturewhile others employ countercurrent circulation in the blood to reduce heat loss.c. Humidity The amount of water vapor in the air
The amount of water in the air expressed as the percentage of saturation vapor pressure is relative humidity Temperature plays a role in climate and to the amount of water it can hold Warm air can hold more water than cold air. If the cool air have constant amount of moisture, the relative humidity increases and if it reaches the saturation vapor pressure it will condense and becomes cloud. When the particles of water or ice become too heavy in the air, it will fall as rain or snow. The relative humidity of the atmosphere greatly influenced the land organisms The greater the humidity the lesser is the risk of dehydration in the organisms Humidity and shortage of available water are very much linked. Areas with low water such as desert have also low humidity. Other factors such as temperature and wind significantly affect the rate of evaporation that affect the humidity. The capability of the organisms to adapt to these variable moisture condition influences their distribution in a habitat. Organisms that have poor water control lives in damp habitat while organism that have the ability to regulate their water intake survive in desert environment.d. Movement of air and water The global pattern of circulation is the vertical movements of the air masses and this is due to the heating and cooling air mass that rise and sink. As the earth spin on its axis, it deflects the air and water to the right of Northern hemisphere and left of the Southern hemisphere called as Coriolis effect. = the effect produces the three types of global wind pattern a. the westerlies b. the northeast trade winds c. the easterlies The movement of air and water significantly influence the ventilation of an organism thus it affects the distribution and survival of organisms
It can serve as dessicating medium especially in windy areas of mountains. The greater is the density and viscosity of the water the slower the movement and so its dessicating effect. The wave action in shore also affects the distribution of the different species. Heavy water with high breaking action is damaging to the organisms in the areas.2. Edaphic Factors Are the physico-chemical properties of soil that limit the abundance and distribution of living organisms Soil is a natural product of unconsolidated mineral and organic matter on Earth’s surface. It is the medium in w/c plant grows and the site of the decomposition of organic matter. Soil served as the habitat of animals and the anchoring medium of plants and source of their nutrients and water a. Soil Characteristics o Soil is a complex mixture of eroded rock, mineral nutrients, decaying organic matter, water, air, and billions of living organisms, most of them microscopic decomposers. o Soil is a renewable resource o Soil was formed from the weathering of rocks and minerals through mechanical or physical weathering for a very long time. o Plants and animals have pronounced influence on soil development when they colonize the weathered rocks o The roots of the plants penetrate the soil and pump up the nutrients converting this to organic form through photosynthesis o When plants die, the bacteria will decompose the debris into inorganic nutrients.
o Some invertebrates like millipedes, earthworms and mites consume the fresh materials in the soil and leave the partially decomposed in the soil through their excreta thereby increasing the amount of inorganic materials in the soil.o Mature soils area ranged is a series of zones called soil horizon, each with distinct texture and composition that varies with different types of soilso A cross-sectional view of the horizons in a soil is called a soil profileo Most mature soils have at least three of the possible horizons 1. The Surface Litter Layer, or O Horizon (Top Layer) Consists mostly of freshly fallen and partially decomposed leaves, twigs, animal waste, fungi, and other organic materials Normally it is brown or black. 2. The Topsoil Layer or A Horizon A porous mixture of partially decomposed organic matter called humus(this material helps retain water and water-soluble nutrients, w/c can be taken up by plant roots) and some inorganic mineral particles. It is usually darker and looser than deeper layers. A fertile soil that produces high crop yields has a thick topsoil layer with lots of humus. This helps topsoil hold water and nutrients taken up by plant roots The color of its topsoil tells us a lot about how useful a soil is for growing crops. For example darkbrown or black topsoil is nitrogen-rich and high in organic matter. Gray, bright yellow, or red topsoils are low in organic matter and need nitrogen enrichment to support most crops. 3. The B Horizon (subsoil) and the C Horizon (parent material)
Contain most of a soil’s inorganic matter, mostly broken-down rock consisting of varying mixtures of sand, silt, clay,and gravel The C Horizon lies on a base of unweathered parent rock called bedrock As the water seeps down, it dissolves various soil components in upper layers and carries them to lower layers in a process called leaching (process in which various chemicals in upper layers of soil are dissolved and carried to lower layers and, in some cases, to the groundwater)b. Substrate texture and structure o Texture is determined by the proportions of the soil particles of different sizes; the sand (medium-size particles) silt (fine particles), gravel (coarse to very coarse particles) and clay (very fine particles). Soils with roughly equal mixtures of clay, sand, silt, and humus are called loams o Loams are the best soils for growing most crops because they hold lots of water but not too tightly for plant roots to absorb o It is important in the movement and retention of water in the soil. o Soil particles, particularly clay-humus complex are important to nutrient availability and to the carbon exchange of the soil o Color is also another identification of soil, pale brown to reddish and yellowish color indicates good drainage of water while dark brown and blackish color indicates poor drainage. o Though the dark colors may indicate the presence of organic matter it does not always indicate its richness in organic matter because some rocks that are volcanic in origin have dark color as well.c. Ph
o The acidity or alkalinity of a soil, as measured by its pH influences the uptake of soil nutrients by plants o The ph of the soil or water influences the distribution and abundance of organisms o A ph that is either too low or too high is damaging to the organisms. o It may also indirectly affect the organism by affecting the nutrient and concentrate the toxin in the soil. o Acidic soil may build up toxic ions while alkaline conditions may trap the nutrients in the soil3. Salinity • Salinity is the measure of salt in the water • It can exert very significant effects on the abundance and distribution of species because of difference in water and ionic control abilities of organism • Hypotonic organisms such as bony fish find it very hard to live in normal seawater because they have high risk of water loss. • Salt tolerant plants (halophytes) tolerate high salinity by concentrating electrolytes in the cell vacuoles while the cytoplasm are left normal.4. Contaminants and pollutants • Contaminants and pollutants are materials that maybe present in the environment that may or may not cause negative biological effects to the organisms • Such materials may be derived from natural and or anthropogenic sources to w/c the organisms may respond differently. • Some species may develop tolerance and protection from the polluting substances such as that of the tolerance of bacteria against antibiotics and that of the insects with the pesticides.
B. LIMITING RESOURCES The resources are the materials that are utilized by the organism for the maintenance of their bodies such as solar radiation, nutrients, food and space Resources may be categorized as essential or substitutable. Essential resources are not replaceable by an alternatives such as nutrients while substitutable are resources that can be partly or wholly replaced when the consumption of the resources has exceeded its maximum ability to support. 1. Light Light is a resource continuum that is comprised of spectrum of different wavelengths that are usable for photosynthesis. Plant utilizes only the wavelength between 400-700 nm and this band is called photosynthetically active radiation (PAR) and falls within visible spectrum. Solar radiation differs from other resources because it passes through the system only once and if it is not captured and used immediately, it is lost. Variation in the amount of solar radiation however, varies depending upon the latitude. Radiation is greatest at low latitudes while seasonal variation is greatest at high latitudes. Systematic variation may influence the control processes of the organism to develop diurnal and seasonal rhythms. Random variations due to cloud cover, shading and reflections of waves affect the plants species by limiting the potential for optimal utilization of light. 2. Inorganic materials Three inorganic materials are considered vital for the living organisms in the environment. a) Water molecules o Needed by all organisms to survive thus influence their distribution and abundance. o It is needed by plant for transpiration (loss of water vapor at the aerial portion of the plant like leaves) and photosynthesis (process where in plants convert radiant energy to chemical
energy) while animals used water as a medium for many metabolic activities in their body. o Animals usually drink water or obtain it from food it takes while plants usually obtain water from the soil using their elaborate root system.b) Carbon dioxide o Is fixed by plants into living materials through photosynthesisc) Oxygen o Becomes a limiting factor in aquatic or water logged sediments because of its role in aerobic respiration of animals 1. Nutrients • Macro and micronutrients are required by organisms to function properly & they obtain these from the food, soil or surrounding water. • Macronutrients include nitrogen, phosphorus, sulfur, potassium, calcium, magnesium and iron • It is required by all organism in large quantities that it become a limiting factor to some organism when it is limited in the environment • The extraction by plants of nutrients from the soil is done through the root system • These are close relationship between water and minerals, so lack of water can make the mineral unavailable 2. Food • The heterotrophic organisms require foods and each organisms is alternately a consumer or a prey within the food chain (series of organisms in w/c each eats or decomposes the preceding one)or food web(complex network of many interconnected food chains and feeding relationships).
• Some organisms are specialist, feeding upon a single species only thus these are restricted closely to source of prey and force to live in patches • Moreover, many food sources are seasonal and the nutritional value may vary with season. • Carnivores have difficulties finding, capturing and handling prey items and most of times, their prey have developed physical or behavioral defenses against their consumers. This process is called coevolution3. Space • All organisms require space within w/c they can live • Plants may require only small space but the top carnivores require bigger space. • Space becomes an important resource because it contains other resource such as food. • However, space is also required by other organisms for their growth, breeding, hibernation and for nesting.