COMMUNITY AND POPULATION ECOSYSTEM All the populations of different organisms within a given area make up the community. Ex: All of the populations in ODTÜ forest
The two factors that make up the environment of an organism: BIOTIC FACTORS It includes all the living organisms in the environment. ex: Producers Consumers Decomposers ABIOTIC FACTORS Light Heat or solar energy Water Minerals Soil Oxygen Wind etc.
Predator Any organism that catches and kills other organisms. Prey Organism that is actively captured and used as food by predators.
Interspecific competition It occurs when two species attempt to utilize the same source when there is not enough of the source to satisfy both. ***Interspecific competition occurs when the niches of two species overlap.
Intraspecific competition Intraspecific competition is a particular form of competition in which members of the same species compete for the same resource in an ecosystem (e.g. food, light, nutrients, space).
Symbiotic Relationships PARASITISM: Endoparasites HIV and other viruses Tapeworm in human intestine Bacteria
Symbiotic Relationships COMMENSALISM: Small fish living with sharks eat the food particles left over from the sharks feeding
Symbiotic Relationships COMMENSALISM: Sea anemone (deniz gülü) and certain fishes which gain portection
Symbiotic Relationships MUTUALISM: Nitrogen fixing bacteria living in the root nodules of legumes Ants and aphids
Symbiotic Relationships MUTUALISM: Fungus Lichen + Algae food and O 2 CO 2, H 2 O, protection, moisture, attachment site
Symbiotic Relationships PROTO-COOPERATION: Crab + sea anemone Food and distribution Protection with tentacles
Symbiotic Relationships PROTO-COOPERATION: Oxpeckers and grazing animals
Although ecosystems appear stable, they do undergo change. Some of the changes tend to make the environment more suitable for new types of organisms. Thus, the original organisms in an ecosystem are slowly replaced by other types. Over time, communities replace each other The process by which an existing community is slowly replaced by another community is called ecological succession. Ecological Succession
Succession of one community by another goes on until a mature, stable community develops. Such a community is called a climax community. In an ecosystem with climax community, the conditions continue to be suitable for all members. The climax community remains until an event such as, fire, flood, or volcanic eruption. After the destruction of climax community, succession begins again and continues until a new climax community develops.
POPULATIONS Population: A group of organisms of the same species living together in a given area or volume. Ex: Human population in Ankara
POPULATIONS Population growth; is the change in the number of individuals within a population. Population growth is a function of number of birth, death, immigrations and emigrations. The population growth rate, abbreviated “r” is the change in population size per individual per unit time: r = Change in number of individuals per unit time Total number of individuals at the beginning of time interval
POPULATIONS Density of population: The number of individuals in a unit area or volume. Ex: number of human in 1 km 2 Carrying capacity: The maximum size of a population that can be supported by an environment. This upper limit is set by the particular resource that is short in supply. Ex: The carrying capacity of algae in a pond may be set by the concentration of phosphate. The carrying capacity of wolves may be set by the availability of elks.
POPULATIONS A population that exceeds its carrying capacity, with more individuals than the environment can support, will return to its carrying capacity as it experiences lower birth rates and greater death rates. A population below its carrying capacity will reach its carrying capacity as it experiences higher birth rates and lower death rates.
POPULATIONS Size of the Population: 1.The size of the population is determined by birth rate and death rate Birth rate: X Death rate: Y If X > Y population increases If X < Y population decreases If X = Y population is almost stable 2. Immigration and emigration also effects the population size. Population size =(Birth rate +immigration) -(Death rate + emigration)
LIMITING FACTORS FOR POPULATION GROWTH AND SIZE 1.LIMITING FACTORS: a) EXTERNAL FORCES *amount of food *migration *epidemics *war *temperature *soil *amount of oxygen *moisture b) INTERNAL FORCES *instinct *social behavior *birth control *the ability to reproduce
2. LIMITING FACTORS a) DENSITY-DEPENDENT: Competition: If two populations compete for the same limiting factor, the competition may become a limiting factor. Ex: The competition of two dogs for a piece of bone is intraspecific competition but the competition of a dog and a cat for a piece of meat is interspecific competition. LIMITING FACTORS FOR POPULATION GROWTH AND SIZE
Predation: In predator-prey relationship, each population continually determines the size of the other. number of prey in an area increases number of predators increase as the predators feed on the prey, the number of prey begins to decrease number of predators also decrease because of the decrease in their food supply LIMITING FACTORS FOR POPULATION GROWTH AND SIZE
Parasitism: If the number of parasites carried by the host is increased, the host will die, this condition decreases the number of population members. Space-food: Space is generally more important for plant populations because they take their nutrients and water from the soil. Since animal can move, the space limits the population after food, disease and predators. Diseases: Population density is also related with diseases Ex: Malaria, the denser human population, the greater chance of disease being passed to others LIMITING FACTORS FOR POPULATION GROWTH AND SIZE
2. LIMITING FACTORS b) DENSITY- INDEPENDENT: Natural disasters such as earthquakes, hurricanes, flood cause decrease in the number of populations. LIMITING FACTORS FOR POPULATION GROWTH AND SIZE
THE GRAPHS OF POPULATION GROWTH 1. THE S -GRAPH no. of individuals time I IIIIIIV I. Initial Growth: At the beginning there are not much individuals in the population (adaptation time for the environment) II. Exponential Growth: Population grows rapidly. The birth rate is greater than the death rate. III. Negative Growth: Increase in the environmental resistance causes a decline in the population size. IV. Stationary state: the birth rate and death rate are almost equal.
THE GRAPHS OF POPULATION GROWTH 2. THE J -GRAPH time no. of individual After the initial growth, the density of population increases logarithmically. But, when the environmental resistance occurs, the size of the population decreases sharply. In this growth graph there is no stationary state, there is a stability time.
HYPOTHESIS ABOUT POPULATIONS 1. Thomas Maltus Hypothesis (1) time no. of individual Food, diseases, space, wars and natural disasters control the growth of a population. Mainly increase in the death rate stabilizes the population.
HYPOTHESIS ABOUT POPULATIONS 1. Thomas Maltus Hypothesis (2) time Numerical increase The number of individuals in the human population increases logarithmically but the food supply increases arithmetically. So, the growth of the population depends on the food supply. Amount of food no. of individuals
HYPOTHESIS ABOUT POPULATIONS 2. Wynne – Edward Hypothesis time The growth of the population is controlled by instinct behaviors. Mainly, decrease in the birth rate controls the population size. no.of individuals inner forces
If the number of young individuals is greater than the number of middle-aged or older individuals, then this population is said to be a growing population. If the number of young and elderly individuals are equal, then the population is said to be a stable population. ***If the number of elderly individuals is greater than the number of young ones, the population is said to be getting smaller. AGE DISTRIBUTION IN HUMAN POPULATIONS
EXPERIMENTS ABOUT POPULATIONS J. Emlen and his colleagues did some experiments with mice populations. I. The amount of food is constant Population size is increased The amount of food becomes insufficient Emigration starts Population size becomes stable RESULT: Emigration causes the stabilty of the population.
EXPERIMENTS ABOUT POPULATIONS ll. The amount of food is constant Population size is increased The amount of food becomes insufficient Emigrations is not allowed Population size becomes stable RESULT: Food affects the rate of birth and emigration from the population. But in two circumstances the aim is to maintain the size of the population. Birth control starts
EXPERIMENTS ABOUT POPULATIONS lll. The amount of food is increased day by day Population size is increased Emigration is not allowed Population size becomes stable RESULT: Although the food is enough but space will determine the size of the population. Birth rate decreases and death rate increases Space becomes insufficient
Habitat destruction Competition Predation Disease Coextinction Global warming @ FACTORS THAT CAUSE EXTINCTION OF SPECIES
Türkiyede Nesli Tükenmekte Olan Hayvanlar Asya aslanı (Panthera leo persica) Kafkas öküzü (Bison bonasus caucasicus) Çita (Acinonyx jubatus raddei) Kelaynak Deniz kaplumbağaları Akdeniz foku (Monachus monachus) Telli turna (Anthropoides virgo) Ceylan (Gazella gazella) Yırtıcı kuşlar İç su balıkları Dağ horozu Van kedisi Dünyada Nesli Tükenmekte Olan Hayvanlar Panda (Bambu Ayısı) Kutup Ayısı Penguenler Kısa Gagalı Yunus Su samurları
BIOMES The term biome refers to a large geographical region that has a particular climax community. In terrestrial biomes, climax community is the dominant plant population.
BIOMES (Decidious Forest) Dominant vegetation is trees such as oak, maple, chestnut, smaller trees and shrubs. Rainfall avarages between 75-150 centimeters a year. Summers are usually hot and humid, and the winters are cold.
Grassland: BIOME (Grassland) Grasses are the dominant vegetation Found in North America, Asia, South America, Europe and Africa Rainfall ranges from 25-75 centimeters a year.
Desert BIOME (Desert) Rainfall is less than 25 centimeters in one year. Found in America, Africa, Asia and Australia Temperatures vary widely between night and day Usually don’t have any vegetation, but on some cacti, yucca and bushes are found. Desert animals are usually active at night
Atatürk bir gün Yalova’daki yazlık köşküne gider. Köşkün yanında bulunan ulu çınar ağacının dallarını kesmeye çalışan bahçıvanı görür ve derhal müdahale ederek, ağacın dallarını neden kestiğini sorar. Bahçıvanın, ağacın dallarının uzayıp, köşkün duvarına dayandığını ve köşke zarar vereceğini ve bu yüzden kesmek istediğini söylemesi üzerine Atatürk, herkesi şaşırtan ve hayrete düşüren bir emir verir. Buna göre, ağacın dalları kesilmeyecek bina kaydırılacaktır. Görev, İstanbul Belediyesi Fen İşleri Yollar-Köprüler Şubesine verilir. Köşkün temeline kadar toprak kazılarak, bina İstanbul’dan getirilen tramvay raylarının üzerine oturtulur ve raylar üzerinde kaydırılarak, çınar ağacından 4.80m. uzaklaştırılır. Atatürk’ün Çevreye Verdiği Önem