Introduction To Ecology And Abiotic Factors PDF

MODULE 1 INTRODUCTION TO ECOLOGY AND ABIOTIC FACTORS WHAT IS ENVIRONMENT?  ENVIRONMENT COMPONENTS : BIOTIC ABIOTIC TYPES : GEOGRAPHICAL OR NATURAL MAN-MADE : outer ( physical) inner ( social) MAN MADE ENVIRONMENT INNER OUTER C...

MODULE 1 INTRODUCTION TO ECOLOGY AND ABIOTIC FACTORS WHAT IS ENVIRONMENT?  ENVIRONMENT COMPONENTS : BIOTIC ABIOTIC TYPES : GEOGRAPHICAL OR NATURAL MAN-MADE : outer ( physical) inner ( social) MAN MADE ENVIRONMENT INNER OUTER Components of Environment Biotic Abiotic Producers/ Physical Autotrophs factors Consumers Chemical 1, 2, 3,.. factors Decomposers Abiotic Components Environmental Resources Conditions Not directly Directly consumed consumed but affect or utilized by growth and survival organisms of organisms Examples: Mineral Examples: elements like N, P, Temperature, K, CO2 salinity, pH Ecology Greek word “oikos” meaning household Logos means “ to study” Earnst Haeckel in 1869 “ Oecologie” science dealing with the interrelationships of living organisms to their environment.  Environmental Science - an interdisciplinary field that incorporates concept from natural sciences and social sciences  Divisions of Ecology Autecology - ecology of individual organisms Synecology - ecology of group of organisms  Interactions Biotic to biotic Biotic to abiotic Abiotic to abiotic ABIOTIC FACTORS AND ADAPTATIONS ABIOTIC LIGHT - visible light or whitelight - wavelenghts of 0.4 to 0.7 microns -PAR ( photosynthetically active radiation Electro Magnetic Spectrum  Roles of Light For photosynthesis For vision Forms visual color Main source of global temperature Source of energy Affects the local distribution of plants in terrestrial and aquatic environment Influences the daily and seasonal activities of plants and animals Light that reaches the surface of the earth may be: reflected absorbed transmitted 6-12 % is reflected in plants 10 -20 % -transmitted - 90% if absorbed in aquatic  Effects of Light Animals - pigmentation - Circadian rhythm -circa “about”, dies “ day” - activity and inactivity – 24 hours - nocturnal and diurnal Biological clock – time keeper  Effects of Light In Plants - photosynthetic reaction - photoperiodism - flowering response - short day, long day and day neutral - transpiration, pigmentation, stomatal movement, nasty movement Soil - isa natural product formed from weathered rock by the action of climate and living organims  Soil composition of soil: water- 25%, gases- 25%, minerals- 40%(e.g. silicon, aluminum, calcium), organic materials -10%.  Importance of Soil Source of anchorage Influence plant activities such as germination of seeds Serve as shelter of animals, storage of waste and source of food. Soil Profile: O layer - organic layer A layer - topsoil; humus B layer - subsoil ; leaching C layer - incomplete fragments of rocks  Soil classification 1. Clay – particles with diameter less than 0.002 mm 2. Silt - diameters between 0.002 and 0.2 m 3. Sand – particles with diameter between 0.02 mm to 2 mm * Loam Soil types  Soil Types Can be classified as : residual soil transported soil  Soil Porosity. There are two types: Micropores- space diameter up to 20 μm – capillary pores Macropores- space diameter up to 20 –50 μm * non-capillary pores  Topography the physical geography of the surface of the earth caused by diastrophism. -is the movement of the solid portion of the earth  Types of Topography Altitude Steepness of slope Exposure to sunlight direction of mountain chains and valleys Importance of Topography Influence the vegetation affects the climatic factors  Effects of Topography - tree line (edge of the forest at high altitude or latitude beyond which no tree can grow) degree of slope influences the soil structure and behavior, swift run-off water. Sunfacing has mesophylous plant nonsunfacing slope - dry has xerophylous plant (requiring small amount of water) continental air circulation. Temperature - is the degree of hotness or coldness on a definite scale.  Importance of Temperature Regulates the metabolism, morphology and physical activities of plants and animals Interacts with other environmental factors such as altitude Affects the distribution of plants and animals Source of thermal or heat energy. Global Temperature Classification Megatherms- refers to tropics with long period of seasons Mesotherms- refers to temperate countries with alternating high and low temperatures.  Global Temperature Classification Microtherms- low temperatures prevail Hekistotherms- areas with very low temperatures  Effects of Temperature to Animals Animals Homeotherm ( warm blooded Poikilotherm ( cold blooded) Endotherm vs. ectotherm Temperature in Animals Animals are either warm blooded (homoiotherm) or cold blooded (poikilotherm)  Effects of temperature Microorganisms are classified as -thermophiles (can tolerate 40-90 oC; -mesophiles (10-45 oC); -psychrophiles(-5 – 40 oC). Water  Water 75% of the earth surface 97% Marine water, 2% solid water in glaciers and snow >1% liquid water in lakes ,rivers and streams  Ecological Types of Water Atmospheric water Precipitation soil water- water on the surface and ground (water table) Bodies of water (e.g. ponds, lakes, streams, rivers, seas and ocean)  Properties of Water universal solvent is liquid at over wide temperature range has neutral ph with three phases : solid, liquid and gas viscosity – is the resistance of liquid to flow  Properties of Water High specific heat Specific heat – number of calories necessary to raise one gram of water one degree celcius * For every one gram of water – one calorie is needed to raise it one degree celcius  Properties of water Latent heat – energy released or absorbed Latent heat of fusion - 80 calories of heat to convert 1 g of ice liquid state high latent heat of vaporization -536 calories to convert 1g of water at to a vapor Ice, water, vapor Water Properties ( Cont..) - has high surface tension – below the surface of water, molecules are attracted, thereby forming thin film due to strong H-bond molecules - has maximum density at 4 degrees Celcius Importance of Water - habitat - regulates temperature - photosynthesis - transporting medium - weathering - source of energy Humidity - Moisture in form of water vapor  Humidity Absolute humidity – amount of water vapor per unit volume of air Relative humidity – measure on amount of water vapor actually in the air relative to the amount of water vapor the air could hold if saturated R. H = Water vapor density x 100 Saturation water vapor density  Humidity Water vapor density – mass of water vapor per unit volume of air - mg H20/L of air or g H20/m3 Temperature of air is indirectly proportional with relative humidity  Types of plants based on water requirements : - Xerophytes - grow on areas with little amount of water - Mesophytes - grow on areas with moderate amount of water Hydrophytes – more than enough requirement of water Halophytes - water with salt Example of Transported soil: alluvial-soil deposited by river flow; colluvial- deposited by gravity or landslide; glacial- deposited by glaciers; eolian- deposited by wind.  Wind -horizontal or vertical movement of air or gases on the surface of the ground. -formed due to uneven heating of land and water causing vertical movement of gases  Importance of Wind Serve as medium for the transport of materials e.g. pollination, cloud transport, rainfall weathering source of energy Affects the morphology and habit of organisms.  Effects of Wind Plants - have stunted growth and leaf damage, lodging (process being laid flat on the ground), Animals- tend to have thick hair, and shelter in caves or under the rock. Land and Aquatic- wind causes abrasion, erosion and salt spray  Wind Speed- expressed in kilometers per hour. Strong breeze - 40-60 kph Gales (Strong wind)- 60-90 kph Storms - 90-120 kph Hurricanes >120 kph  Fire is the result of a chemical reaction called combustion At a certain point in the combustion reaction, called the ignition point, flames are produced Flames consist primarily of carbon dioxide, water vapor, oxygen, and nitrogen.  FIRE Based on sources , it may be classified as : natural fire : lightning, volcanic eruptions, or friction of dried twigs and burning of dried leaves due to thermal heat. -anthropogenic - brought by human activities  Fire can burn at three levels Ground fires – organic matter down to mineral substrates Surface fires -the shrubs, herbs and bases of trees. Crown fires- canopy of trees and most destructive.  Effects of Fire Destroys the vegetation and drive all away animals. Plants with scars caused by fire will be prone to disease and parasites attacked Eliminates diseases and pest such as fungi, nematodes and insects  Ecological Importance of fire Removes competition of surviving plants, pests, parasitism and diseases Increases light intensity Modifies the pH, elements and organic materials of the soil. Controls the weeds, and maintains the grassland