14 1 Habitat And Niche KEY CONCEPT Every

14. 1 Habitat And Niche KEY CONCEPT Every organism has a habitat and a niche.

14. 1 Habitat And Niche Objectives • Differentiate between a habitat and a niche • Differentiate between competitive exclusion and ecological equivalents

14. 1 Habitat And Niche A habitat differs from a niche. • A habitat is all aspects of the area in which an organism lives. – biotic factors – abiotic factors • An ecological niche includes all of the factors that a species needs to survive, stay healthy, and reproduce. – food – abiotic conditions – behavior

14. 1 Habitat And Niche Resource availability gives structure to a community. • Species can share habitats and resources. • Competition occurs when two species use resources in the same way. • Competitive exclusion keeps two species from occupying the same niche.

14. 1 Habitat And Niche • Competitive exclusion has different outcomes. – One species is better suited to the niche and the other will either be pushed out or become extinct. – The niche will be divided. – The two species will further diverge.

14. 1 Habitat And Niche • Ecological equivalents are species that occupy similar niches but live in different geographical regions. Madagascar South America

14. 1 Habitat And Niche What are the 3 parts of an organisms ecological niche? • Food type • Abiotic conditions • Behavior

14. 1 Habitat And Niche What does the principle Competitive Exclusion say will happen when 2 species compete for the same resource? • One species will be better suited to the niche, and the other species will either be pushed into another niche or become extinct

14. 1 Habitat And Niche If a group of mantella frogs were transported to the ecosystem of the poison dart frogs, what might happen to the 2 species populations? • As ecological equivalents, they share a similar niche. • The population better suited to the niche might deprive the other of resources, causing the other to die off. OR • One population might respond to limitted resources by altering its niche.

14. 1 Habitat And Niche A bison and an elk live in the same habitat and feed on the same grasses. Does this mean that the competitive exclusion principle does not apply? Expleain. • The competitive exclusion principle only applies if the 2 species live in the same habitat AND occupy the same niche • A niche includes – Food type – Abiotic conditions – Behavior • These two species use the same food resource but occupy different niches

14. 1 Habitat And Niche Considering the competitive exclusion principle, why may it be harmful to transport a species such as a rabbit, to another habitat where it currently does not exist? • If a new species is introduced to an area, it may occupy a similar niche as a native species and be better adapted for the niche to have no natural predators. • This could drive the native species to extinction

14. 2 14. 1 Habitat And Niche KEY CONCEPT Organisms interact as individuals and as populations.

14. 2 14. 1 Habitat And Niche Objectives • Compare & Contrast interspecfic and intraspecific competition • Describe the 3 types of symbiosis

14. 2 14. 1 Habitat And Niche Competition and predation are two important ways in which organisms interact. • Competition occurs when two organisms fight for the same limited resource. – Intraspecific competition – Interspecific competition

14. 2 14. 1 Habitat And Niche • Predation occurs when one organism captures and eats another.

14. 2 14. 1 Habitat And Niche • There are three major types of symbiotic relationships. – Mutualism: both organisms benefit

14. 2 14. 1 Habitat And Niche • There are three major types of symbiotic relationships. – Commensalism: one organism benefits, the other is unharmed Ø Human Our eyelashes are home to tiny mites that feast on oil secretions and dead skin. Without harming us, up to 20 mites may be living in one eyelash follicle. Commensalism Ø Organism is not affected + + Organism benefits Demodicids Eyelash mites find all they need to survive in the tiny follicles of eyelashes. Magnified here 225 times, these creatures measure 0. 4 mm in length and can be seen only with a microscope.

14. 2 14. 1 Habitat And Niche • There are three major types of symbiotic relationships. – Parasitism: one organism benefits, the other is harmed 0 Parasitism _ + Hornworm caterpillar The host hornworm will eventually die as its organs are consumed by wasp larvae. _ Organism is not affected 0 Braconid wasp Braconid larvae feed on their host and release themselves shortly before reaching the pupae stage of development. Organism benefits

14. 2 14. 1 Habitat And Niche • There are three major types of symbiotic relationships. – Parasitism meet their needs as ectoparasites (such as leeches) and endopaasites (such as hookworms)

14. 2 14. 1 Habitat And Niche During the fall spawning of salmon, grizzly bears fight over space on the banks of a river. What type of competition is this? • The bears are fighting amongst themselves so it is considered intraspecific competition

14. 2 14. 1 Habitat And Niche Describe and give an example of the 3 types of symbiosis • Mutualism +/+ • Commensalism +/0 • Parasitism +/-

14. 2 14. 1 Habitat And Niche How are predation & parasitism similar? How do they differ? • Predation & parasitism are both relationships in which one organism benefits while the other is harmed. • In predation, the predator needs to kill its prey in order to benefit • In parasitism, the parasite benefits by keeping its host alive

14. 2 14. 1 Habitat And Niche After a lion has made a kill birds will sometimes arrive to pick at the carcass. The birds would be considered _____(A)_________ while the lions would be considered _____(B)___________ • A) Scavengers • B) Predators

14. 3 14. 1 Habitat And Niche KEY CONCEPT Each population has a density, a dispersion, and a reproductive strategy.

14. 3 14. 1 Habitat And Niche Objectives • Consider density and geographic dispersal as characteristics of populations • Describe 3 basic types of survivorship curves in relation to reproductive strategies.

14. 3 14. 1 Habitat And Niche Population density is the number of individuals that live in a defined area. • Population density is a measurement of the number of individuals living in a defined space. • Scientists can calculate population density.

14. 3 14. 1 Habitat And Niche Geographic dispersion of a population shows how individuals in a population are spaced. • Population dispersion refers to how a population is spread in an Clumped area. dispersion Uniform dispersion Random dispersion

14. 3 14. 1 Habitat And Niche • There are three types of dispersion. – clumped

14. 3 14. 1 Habitat And Niche • There are three types of dispersion. – uniform

14. 3 14. 1 Habitat And Niche • There are three types of dispersion. – random

14. 3 14. 1 Habitat And Niche Survivorship curves help to describe the reproductive strategy of a species. • A survivorship curve is a diagram showing the number of surviving members over time from a measured set of births.

14. 3 14. 1 Habitat And Niche • Survivorship curves can be type I, II or III. – Type I—low level of infant mortality and an older population – common to large mammals and humans – Type II—survivorship rate is equal at all stages of life – common to birds and reptiles – Type III—very high birth rate, very high infant mortality – common to invertebrates and plants

14. 3 14. 1 Habitat And Niche An Organism has 10 offspring. Two of these offspring die each year over a 5 year period. Is this organism more likely to be a bird or insect? Explain. • The organism is a bird because the mortality pattern described is closest to type II. • Insects tend to be type III, with many offspring and high mortality early in life stages

14. 4 14. 1 Habitat And Niche KEY CONCEPT Populations grow in predictable patterns.

14. 4 14. 1 Habitat And Niche Objectives • Describe 4 characteristics that affect population size • Compare exponential and logistic population growth • Identify factors that limit population growth

14. 4 14. 1 Habitat And Niche Changes in a population’s size are determined by immigration, births, emigration, and deaths. • The size of a population is always changing. • Four factors affect the size of a population. – immigration – births – emigration – deaths

14. 4 14. 1 Habitat And Niche Population growth is based on available resources. • Exponential growth is a rapid population increase due to an abundance of resources.

14. 4 14. 1 Habitat And Niche • Logistic growth is due to a population facing limited resources.

14. 4 14. 1 Habitat And Niche • Carrying capacity is the maximum number of individuals in a population that the environment can support. • A population crash is a dramatic decline in the size of a population over a short period of time.

14. 4 14. 1 Habitat And Niche Ecological factors limit population growth. • A limiting factor is something that keeps the size of a population down. • Density-dependent limiting factors are affected by the number of individuals in a given area.

14. 4 14. 1 Habitat And Niche • Density-dependent limiting factors are affected by the number of individuals in a given area. – predation – competition – parasitism and disease

14. 4 14. 1 Habitat And Niche • Density-independent limiting factors limit a population’s growth regardless of the density. – unusual weather – natural disasters – human activities

14. 4 14. 1 Habitat And Niche What 4 factors determine the growth rate of a population? • Immigration • Births • Deaths • Emigration

14. 4 14. 1 Habitat And Niche How does carrying capacity affect the size of a population? • Carrying capacity limits the size of a population

14. 4 14. 1 What Habitat And Niche is the main difference between a densitydependant limiting factor and a density-independent limiting factor? Give an example of each. Density-Dependant Density-Independant • A density dependant limiting fact is affected by the number of individuals in a given area • A density independent limiting factor is not affected by population size/density – These are usually BIOTIC limiting facto=rs such as Predation Competition Disease – These are usually ABIOTIC limiting factors such as Weather Forrest fires Natural disasters Human activities

14. 4 14. 1 Habitat And Niche What might cause exponential growth to occur only for a short period when a new species is introduced to a resource filled environment. • Eventually, the growing population will consume all the resources, and the species may experience a population crash.

14. 4 14. 1 Habitat And Niche Give an example of how a symbiotic relationship could cause a population to crash. • If a parasite or disease spreads in a dense population, it could cause a population to decline dramatically over a short period of time.

14. 5 14. 1 Habitat And Niche KEY CONCEPT Ecological succession is a process of change in the species that make up a community.

14. 5 14. 1 Habitat And Niche Objectives • Describe the process of primary succession • Explain the difference between primary and secondary seuccession

14. 5 14. 1 Habitat And Niche Succession occurs following a disturbance in an ecosystem. • Succession regenerates or creates a community after a disturbance. – a sequence of biotic changes – damaged communities are regenerated – new communities arise in previously uninhabited areas

14. 5 14. 1 Habitat And Niche • There are two types of succession. – primary succession — started by pioneer species

14. 5 14. 1 Habitat And Niche • There are two types of succession. – secondary succession — started by remaining species

14. 5 14. 1 Habitat And Niche How is primary succession different from secondary succession? • Primary succession begins with barren rock, worn down and colonized with a pioneer species • Secondary succession begins with established soil in which many different plants can grow

14. 5 14. 1 Habitat And Niche Why are pioneer species so important for primary succession? • Pioneer species such as mosses and lichens can break down rock into smaller pieces. • When they die, their remains may mix with the pieces of rock forming a thin layer of soil • They change the ecosystem in ways that enable the support of more diverse species

14. 5 14. 1 Habitat And Niche Does the process of primary succession take longer in the tropical or arctic areas? Explain. • Primary succession takes longer in arctic areas because – rock is covered in snow part of the year – the growing season is shorter – and cold temperatures slow growth and decomposition • Soil takes much longer to form.

14. 5 14. 1 Habitat And Niche Which reaches a climax community 1 st, an area undergoing primary or secondary succession? Explain • Secondary succession takes less time to reach a stable climax community because the soil is already there • In primary succession there is no soil and so it will take longer to reach a climax community

14. 5 14. 1 Habitat And Niche During succession, what might be the limiting factor for sun-loving mosses as taller plants begin to grow? • The amount of sunlight that reaches them

14. 5 14. 1 Habitat And Niche At what point during primary succession does an ecosystem provide the fewest habitats for an organism? Explain. • There are no habitable areas in the earliest stages of succession because there is no soil to support producers. . • Land becomes habitable once rock has weathered enough to support mosses and lichens • Over time mosses and lichens will provide the resources needed to support other organisms