ECOLOGY COURSE CODE STB 222 5 Credit Unit

ECOLOGY COURSE CODE: STB 222 5 Credit Unit FOR NATIONAL DIPLOMA IN SCIENCE LABORATORY TECHNOLOGY YEAR 2 – SEMESTER 1 DEPARTMENT OF PURE AND APPLIED SCIENCES TARABA STATE POLYTECHNIC SUNTAI Course lecturer: WANMI, Danjuma Abner 2019/2020 Academic Session

Ecology What Is Ecology • Ecology is the study of the relationships of living organisms to each other and their surroundings. Habitat • The place where an organism lives, it its habitat. It is a place that is suitable to its way of life. Kinds Of Habitat The main types of habitats are; • Fresh water, e. g. pond, streams and rivers • Salt water (marine), e. g. oceans and seas • Terrestrial habitats, e. g, farmland, savanna, rainforest and deserts • Arboreal habitats, e. g. tree trunks, tree tops and air Vegetation Zones Of Nigeria And Africa The local biomes in Nigeria can be divided into: • Forest and • Savanna

Diagnostic Features Of Nigeria’s Biomes – Mangrove Swamps: These are found in the tropics, along coastal regions and river months. In Nigeria, mangrove swamps are found in the delta regions of Lagos, Delta, Edo, Rivers, Ondo and Cross Rivers States. – Tropical Rainforest: These occur in regions that lie between the equator and latitude 5 – 10 N and S. – Savanna: Tropical grasslands are often called savanna. The savanna is usually flat for miles at a stretch. o • • Southern Guinea Savanna Northern Guinea Savanna Sudan Savanna Sahel Savanna

• Ecological Niche – An organism is usually confined to a particular part of a habitat, e. g. caterpillars and an aphid, which live on the same plant occupy different positions or ecological niches on the plant. • Environment • The environment of an organism consists of all the factors in its surroundings that affect it. Such factors include the: – Place where the organism lives and physical conditions of the place like light intensity, temperature, humidity e. t. c. – Food, water and air that it takes in for its activities – Animals that prey on it, and – Diseases that affect it • Measurement Of Ecological Factors – Ecological factors that require measurement

1. Instrument Functions/uses 2. Rain gauge Measuring the amount of rainfall 3. Thermometer Measurement the lowest and highest temperature of the day 4. Anemometer Measuring the speed of wind 5. Wind vane Indicate the direction of wind 6. Hygrometer Measures relative humidity 7. Barometer Measures pressure 8. Photometer or light meter Measures light intensity on land 9. Hydrophotometer Measures light intensity in water 10. Colorimeter or p. H indictor Measures acidity or alkalinity of soil or solution 11. Tullgren funnel Compares the numbers and types of animals in difference soil 12. Baermann funnel For collecting tiny organisms that live in soil water 13. Sacchi disc Measures the turbidity or transparency of water 14. Tape Measures height and length of objects 15. Thermograph For long period recording of temperature and relative humidity 16. Meter rule Measures the length of objects 17. Water speed meter Measures speed of water flow 18. Slope gauge Measures slope of an area of land

• Succession – A gradual or progressive series of changes occurring in the structure, composition, variety or diversity and number of species in an area till a stable or climax community is established. • The main characteristics of succession include; – – – – Succession occurs in newly formed habitat, Increase in number organisms Succession is orderly and progressive Competition among organisms Diversity of organisms Plants form the pineer organisms Changes in species composition Changes in habitat • Outcome Of Succession • Types Of Succession

Outcome Of Succession results to: – Replacement by complex organisms – Changes in the physical environment – Fast replacement – Attainment of equilibrium point – Climax community form the final stage

Types Of Succession • Primary Succession: Starts on bare surfaces which have not previously borne vegetation. It usually starts with lower organisms and takes a longer time to reach a climax community. Examples of primary succession are commonly found in ponds, vegetation on rocks, mangrove forest an estuary. • Secondary Succession: Starts on already colonized surface. It may start with fairly complex organisms and it takes a shorter time to reach a climax community. Typical examples are found in abandoned farm and grasslands.

Major Communities In A Plant Succession • The three major communities in a plant succession are: – Pioneers (early colonizers): Usually small, lower plants, and highly drought resistant organisms. They require minimum space, substratum or nutrients. They are highly adapted to growing on bare surfaces e. g lichens, algae, mosses and liverworts. – Developmental, intermediate or transitory communities: include series of communities which follow the pioneers with each succeeding communities more complex than the one it replaced. They have more diverse species with greater number of individuals. Include: herbivours plants such as Talinum, Azeratum, imperata cylindrical, cyanotus and sida acuta. – Climax community: Refers to the terminal plant succession or stable community which establishes equilibrium with ecological condition within the locality. They are the most complex in the series of communities in succession with greatest species diversity, as

Process of succession in abandoned farm land • Nutrients remain from the destruction of the old farm • Initial pioneers are insectieggs, larvae, worms, seeds of plants and underground stems • Second stage of succession involve the germination and growth of more • grasses, the hatching of eggs of insects and other species. • Vegetation is now able to support more animals e. g. rats, other rodents, snakes and reptiles • In the third stage, the herbs are replaced by shrubs and increases in the diversity of species • In the fourth stage, more trees grow and species diversity include birds, snake, • reptiles and monkeys, which live in different strata of the habitat. • Population and activities of detritus feeders increased • Climax vegetation is reached • Animal community will now include: herbivores, carnivores and detritus feeders which are involved in a complex food web.

• Problems Of Organisms In Their Habitat • An organism environment, typically the conditions in which it lives, may be sub divided into physical (abiotic) and biotic environment. Both drastically affect the distribution or organisms in different habitats

Abiotic factors confronting organisms in their habitat • Temperature: The narrowness of the temperature range over which biochemical processes can function efficiently implies that organism, wherever they live, must have the necessary physiological or behavioral adaptations to combat the extremes of environmental temperatures. • Water: The extent to which an organism is dependent on an abundant water supply depends on its requirements and its ability to conserve it in adverse conditions. Organisms living in dry habitats generally have good water conservation • Light: This is essential for all green plants and photosynthetic bacteria, and for all the animals dependent on plants. Plants have numerous adaptations for obtaining optimum illumination. • Humidity: It is important because it can affect the rate at which water evaporates from the surface of an organism, which in turn influences its ability to withstand drought. • Wind and Air currents: It is applicable to plants. Only plants with strong root systems and tough stems can live in exposed places where winds are fierce.

Biotic factors confronting organisms in their habitat • An organism biotic environment is made up of all the other organisms with which it comes into regular contact. Below are some examples; – Predation: An organism may feed on, or be fed on by, other organism. In such case the distribution of feeder and fed are related. Thus herbivores are only found where there is suitable plant food; carnivores plants where there are suitable insects predators where there is suitable prey. – Competition: Organisms Frequently Complete with one another for such commodities as food, light, water, shelter, mate or resting site. Competition has resulted in all manner of adaptations. – An organisms may use another as a habitat. Typical example is seen in parasitism

Adaptive Features Of Some Plants In Fresh Water Habitat • Water lity (Nymphaea): The plant has air bladder, expanded shape and light weight which keep it afloat. It has long petioles attached at the centre of leaf blade which prevent them from being drawn under water by the current. • Water hycinsh (Ipomea gtassipis): They have cavities and intercellular air spaces which give them the ability ot float or maintain buoyancy on water. • Spirogyra: The plant has mucilaginous cover which protect them in water • Water lettuce (pistia): Has hairs on their leaves which help them to trap air and enable them float. • Hornwort (eratophyllum): Have submerged on this dissected leaves which increase their surface area to sunlight and gaseous exchange. • Water weed (Elodea): The plant has a long and flexible submerged petiole which enables it to swing with water currents.

Adaptive features of some animals in fresh water habitat • (1) Protozoa: These animals posses contractile vacuoles which enable them to carry out osmoregulation in water • (2) Tilapia fish: Have swim bladders which enable them to float (buoyancy) in water. They also have gills for respiration • (3) Duck: Has webbed digit on its feet for easy locomotion and serrated beak for sieving food in water into its mouth • (4) Lung fish (protopterus): The animals obtain oxygen through the gills but when the water dried out during the dry season, they dig into the mud and breathe with lungs until the rain comes again. • (5) Water boatman: This animal can carry bubbles of air with it as it goes below the water surface to the bottom and use these as their air supply (respiration) underwater.

Adaptive features of some plant species in estinarine (brackish water) habitats • (i) Planktons (diatoms): Have air spaces in their tissues, rhizoids or false feet for • attachment to rock shores and air bladder for buoyancy. • (ii) Algae: Have chlorophyll for photosynthetic activities and small size or large • surface area for floating • (iii) Red mangfrove (Rhizophora racemosa): Has silt roots which grow down from the stem in the soft mud and develop numerous rooflets which have air spaces for conducting air to the tissues of the roots. The roots also provide support and prevent plants from being washed away by the tides. Seeds also germinate while still on the parent plant thus preventing seedling from being carried away by water current. • (iv) White mangrove (Avicennia nitida): It has pneumatophores or breathing roots for exchange of gases.

Adaptive features of some animals species in estuarine (brackish) habitat • (1) Mosquito larvae and pupae: Posses breathing trumpets for gaseous exchange • (2) Crabs: Can burrow fast into the mud against predators, strong waves or tides • (3) Water snails and shrimps: Can burrow into the mud when the tide is going out, • thus escaping the periodic dilution of its external medium • (4) Worms: Have strong protective and impermeable covering against high salinity • (5) Fishes: Like tilapia have fins for movement and swim bladder of buoyancy • (6) Mud skippers: Fins adapted for crawling when on ; land for swimming when • in water

Population Studies • Definition: Population is defined as the total number of organisms of the same species living together in a given area at a particular time. • In population studies of a habitat, the following are usually studied: – Types of organisms: It helps to determine the relationships that exist between the various organisms – Population characteristics: These characteristics include: • • • Population size Population density Population frequency Percentage cover Population growth rate

Factors Affecting Population • Factors which may affect the population of organisms in a given habitat include: – Natality (birth rate): – Mortality (death rate) – Immigration (dispersal) – Emigration – Availability of food – Seasonal Climatic Changes – Breeding periods – Natural Disasters

Method of Population Study Population Studies by Sampling Method • Population studies can easily be carried out in a habitat especially in terrestrial habitat by sampling method, using an instrument called the quadrat. • A quadrat is made of a square or rectangular wire, plastic, wooden or metal frame with predetermined area. • For example, the area of a quadrat may be 1. 5 m 2.

How to Conduct Population Studies • The population size or total population and population density of a particular species in a terrestrial habitat can be estimated by the following procedure: i. Choose and locate the sample plot; ii. Then identify the species in the plot; iii. Measure the area with a measuring tape to know the area of the habitat; iv. Throw or toss the quadrat randomly at intervals for up to 10 or above times. v. After each throw or toss, the number of species within the area of quadrat is recoded; vi. The density of species is calculated by dividing the average number of times the species occurs within the quadrat by the area of the quadrat. • The calculation can be worked out this way a. Frequency of species = X b. Number of toss = Y/10 c. Average number of species per quadrat = X = Z

Ecological Factors Meaning: Ecological factors are those factors in the environment which can influence • living organisms or cause changes in any habitat, be it aquatic or terrestrial habitat. • Ecological factors are grouped into two categories Biotic and Abiotic factors. Biotic Factors • The biotic factors are made up of the effects of other plants and animals on a given organisms. Examples of biotic factor are: • Competitions: Competition involves the interactions among two organisms of the same species or different species in which one neither outgrows the other nor survives while the other cannot grow nor survive. • Parasitism: This is a close association between two organisms in which one called the parasite lives in or on, and feeds at the expense of the other organisms called the host. • Commensalism: Commensalism neither is an association between two organisms living together in which only one (the commensal) benefitted nor is harmed. • Predation: Predation is a type of association between two organisms in which the predator kills the other called the prey and feeds directly on it. • Pathogens: These are micro‐organisms which can cause diseases in plants and animals leading to their reduction through death. • Mortality: Mortality is the death rate of organisms (plants or animals) in an environment. Mortality generally reduces the population of organisms in any habitat. • Migration: This is the movement of organisms either into a new habitat (immigration) or out of a habitat (emigration). • Dispersal: Dispersal is the spreading of new individuals from their parents to new habitat so as to start a new life in the new environment. • Natality: This is the rate of giving birth to new offspring. Natality is generally known to increase the population of the habitat which will subsequently lead to certain problems among the organisms in that habitat. • Food: Availability of food in a habitat generally leads to increase in population while lack of food leads to starvation and dearth. • Diseases: Diseases are known to reduce the population of organisms (both plants and animals) in any habitat. • Pest: Pest are also known to affect the performance of plants in terms of yield and growth, in severe cases, the plants may even die.

Abiotic Factors • The abiotic factors comprise the following; • Climatic factors: These are temperature, rainfall, wind, pressure, sunlight or sunshine, humidity e. t. c. • Chemical factors: These are made up of oxygen carbon dioxide, mineral salts, water and nitrogen. • Edaphic factors: These consist of soil, its water, chemical and physical composition, its p. H, its nutrient, profile, structure and texture. • Topographic factors: These are caused as a result of the shape of the earth’s surface, e/g. effects of rivers, hills, mountains and valleys.

Ecological Factors common to all Habitat. • Factors affecting or common to all habitats (both aquatic and terrestrial habitats) include: – Temperature – Rainfall – Light – Wind – Pressure – Hydrogen ion concentration (p. H). – Of these factors, Salinity, Turbidity/Transparency, Dissolved Gases, Density, water Current, Total movement and waves.

Soil as an Ecosystem Soil profile • The structural base of the entire community is the soil. It supplies the fundamental reserviour in terms of nutrients and water. • It is both an aquifer and basic food bank. • The soil itself is composed of strata or layers called horizons, each with definable properties. • The upper layer, or horizon A, commonly called the top soil, consists of the living roots of vascular plants, the mycelia of fungi, a great abundance of bacteria, protozoa, algae, and other microorganisms, and a surprising variety of burrowing animals • The second major stratum of soil, horizon B otherwise called sub-soil, consists of a mixture of the underlying parent materials and inorganic compound, which have filtered downward from the processes of decomposition in horizon A. • The third major layer of soil, horizon C, otherwise called the bedrock, consists of basic parent materials or the substrate. It may be of sedimentary origin resulting from water deposition (alluvial), glacial activity (glacial tilt) or wind deposition (Aeolian), or it may also be igneous, metamorphic or volcanic in origin.

Components of Soil • A soil consists of four main parts arranged in decreasing order of quantity as follows: – Mineral or rock materials; – Organic matter from plant and animal residues; – Water; – Air

Plant Nutrients These are elements that are essential for normal activities of plants and cannot be replaced by other elements. They are two types: a. Major (Macro) Nutrients • These are elements that are required in large quantities for the normal functioning of plants. They are carbon (C), nitrogen (N), oxygen (O), hydrogen (H), phosphorus (P), potassium (K), sulfur (S), calcium (Ca) and magnesium (Mg). b. Trace (Micro) Nutrients • These are those elements that are required in trace quantities for proper growth and development of plants. They are boron (B), copper (Cu), zinc (Zn), molybdenum (Mo), iron (Fe), cobalt (Co), manganese (Mn), sodium (Na) and chlorine (Cl). Deficiency of any of the above nutrients in plants produces some deficiency signs or symptoms.

Symptoms of Nutrient Deficiency in Plants Nutrient 1. Nitrogen 2. 3. 4. 5. 6. 7. 8. Phosphorus Potassium Calcium Sulphur Iron Zinc Manganese 9. Boron 10. Molybdenum Deficiency symptoms Yellowing of lower leaves, few branches, few leaves dropping of leaves. Purples leaf colour Scorching and browning of leaves Dying back of the tips of leaves Yellowing of both upper and lower leaves Yellowing of upper (young) leaves Bleaching effect, young leaves almost white Vein‐banding in young leaves (yellowing between veins) White irregular spots between the veins Upper leaves wilt and die along the margins

Relationship Between Soil Types and Water Holding Effects of Soil on Vegetation • Soil is define as the uppermost layer of the earth crust which provides support and nutrients for plant growth, and a habitat for some animals • Sandy soil: A soil is said to be sandy if the proportion of sand particles in a sample of soil is very high. The particles are mainly quartz (Si. O 2) and having a size of 0. 02 mm to 2. 0 mm in diameter. Effects on Vegetation: sandy soil is low in plant nutrients as a result of high level of leaching; hence it supports scanty vegetation or grassland. • Clay soil: A soil is said to be clayey if the proportion of clay in a sample of soil is very high. The relative size of a clay particle less than 0. 002 mm in diameter. It is a heavy soil because it is difficult to work or cultivate. Effect on Vegetation: Clay soil has little ability to retain plant nutrients, hence it can support light vegetation such as the forest and some luxuriant vegetation such as savanna or shrub. • Loamy soil: as a mixture of sand clay particles with high proportion of organic matter. Loamy soil is more fertile than either clay or sandy soil. Effect on Vegetation: Contains plant nutrients. It is the best soil in which plants can grow. Loamy soil supports luxuriant vegetation such as forest.

• Water holding capacity of soils is the ability of soil to retain water. Factors that affect water holding capacity of soil as include the following: i. iii. iv. v. Organic matter content Size of soil particle Soil texture Clay content Mineral salt/p. H

Erosion • Definition of Erosion • Factors Effecting Wind Erosion – Speed – Topography – Soil minerals Control Of Wind Erosion ü ü ü ü shelter belts Strip Cropping Cover Cropping Straw Planting Mulches Synthetic Stabilisers Claying And Marling Cultivations

POLLUTION • Definition: Pollution is defined as the release of toxic or harmful substances into the environment by their natural forces or man and other animals to an extent that causes biological damage to man and his resources. • Type of Pollution – a. Air pollution – b. Noise pollution – c. Land pollution – d. Water pollution

Air pollution • The major air pollutants: Carbon monoxide, Sulphur dioxide, Nitrogen oxide, Smoke, Dust particles, Radio‐active rays • Control air pollution – Conditions must be carried for complete combustion of fuel in internal combustion engine. – Chemical waste should be discharged into the air through fumes chambers. – Industries should be sited far away from residential areas,

Noise pollution • Pollutant: Noise • Sources – – – Factory or industrial noise Aeroplance or aviation noise Railway engine or locomotive noise, Car horns and sirens High pitched musical sound from loud speakers or drumming Noise from heavy guns • Effects of noise pollution – Causes loss of hearing or deafness – Noise can cause emotional disorder, anxiety or lack of concentration. – Noise can also cause high blood pressure or hypertension • Control – There should be reduction of noise from loud speakers and cars sirens. – Legislation should be made against the use of loud speakers in public places. – Ban on the use of heavy guns must be placed

Land Pollution • Major land pollutants: Refuse, Sewage, Metal scraps, Pesticides, fertilizer, Glass particles, Crude oil • Control of Land Pollution – Refuse should be burnt in incinerators. – Urban wastes should be properly burnt or buried – Sewages should be properly treated before disposal

Water Pollution • The major water pollutants: sewage, Pesticides, fertilizers, Chemical wastes, excreta, Crude oil. • Control Water Pollution – There should be efficient and proper sewage disposal system – Dumping of refuse or petro‐chemical by‐products into rivers, streams – Industrial effluents should be recycled

Sewage • Sewage is society water-borne waste – Domestic sewage contains human faeces and urine, the water used to wash these away and the dirty water that flows from our baths and sinks. – Industrial sewage: includes the dirty water from industry, hospitals and abattoirs. – Agricultural sewage: Derived from farms, is not allowed to mix with domestic and Industrial waste, and is treated separately. • Eutrophication: Eutrophication is the enrichment of water with nutrient when large amounts of organic matter, or nitrogen and phosphorus, enter the water. A chain reaction then occurs, as a result of which the oxygen level of the water falls and many organisms die. ü The degree of eutrophication in a body of water can be determined by measuring the rate at which a sample of the water takes up oxygen in the dark. This is known as the biological oxygen demand (BOD). ü The higher the BOD, the greater the number of aerobic microorganisms in the water and the greater the degree of eutrophication. • Treatment Sewage – biological filter system – activated sluge system

Toxic actions of Chemical Substances • Toxicity is the ability of a material to injure a living organism by other than mechanical means. • Mode of Entry – Ingestion – skin absorption – Inhalation MODE OF ACTION – The action taken by the material on the body and / or the action taken by the body – because of contact with the material can range from nil to a complex network of interrelated activities.

ACTION AT THE SITE OF CONTACT • All irritants have an action (irritation) at the site of contact. • In many cases that action is severe enough and rapid enough to warn of a contact that may be dangerous if the warning is neglected. • On the other hand, fibrogenic dusts that are not irritating in the usual sense of the word and some other materials also act at the site of contact.

ABSORPTION INTO BLOOD • Whether or not there is any action on the skin, lungs, or stomach, the material may be absorbed into the bloodstream from the site of contact. • This never happens with perfect efficiency and, therefore, some sort of a distribution coefficient may be determined it enough is known about the absorption process.

ACTION ON BLOOD • Under most circumstances, the blood simply transports material that has been absorbed. • Some substances, however, have an action on the blood itself as exemplified by carbon monoxide and aromatic amines. • These materials act on hemoglobin to reduce the ability of that protein to carry oxygen from the lungs to other tissues. • Direct action on the blood other than interference with hemoglobin is very unusual except for some living disease entities.

ABSORPTION INTO TISSUE • For any other tissue in the body, a second distribution coefficient usually can be calculated to present absorption from the blood. • As with the more external coefficient, care must be taken in the use of an internal coefficient that may be modified by – Exercise – nutritional state – temperature, and so forth

SITE OF ACTION • Usually one organ or one organ system will be more sensitive to the material or may absorb more of the material than any other effects. • The major site of action may be the kidneys, liver, heart, brain, or even a small portion of one of these organs such as the glomerulus’s in the kidney.

TOXIN ACTION • Toxicity is a property of matter, • It is a biological property, implying that the variability of response will be much greater than that found in physical systems • toxicity is that it may differ from individual in addition to differing from species to species

INDUSTRIAL TOXICOLOGY • Industrial toxicologists are concerned with the effects of industrially encountered materials on man. • The toxicologists commonly experiment on animals but usually are interested in the results • Industrial toxicologists usually confine their efforts to the effects of materials and leave the effects of energies such as sound and radiation to others who specialize in those fields. • The industrial toxicologist may not be employed by industrial but may work in a government laboratory, at a university, or for a consulting firm. • His interests. Not his place of employment, determine his profession. • The toxicologist will need or will determine the following information: – – General chemical and physical properties of the material Procedures for detecting and determining the toxic agent The mode of action of the toxic material The dose‐response relationships

DOSE RESPONSE • No two biologic entities, even within the same species, react exactly alike to an insult from a toxic chemical agent. • This variability or response is even greater between species than it is within a given species. • To enable a comparison of the toxicity of materials over long time spans, the toxicologist may use standardize strains or varieties of his experimental subjects. • When he doses a laboratory rat today with a material, the results will be similar to those observes when that same material was given to rats of the same inbred, genetically stable strain 2 decades ago (4).

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