Population Ecology PDF

POPULATION ECOLOGY ZGE 4301– Environmental Science Department of Biological Sciences University of the East - Manila Population Ecology Studyof interaction within populations; how it changes through time Study of population in relation to the environment Population  group of individ...

POPULATION ECOLOGY ZGE 4301– Environmental Science Department of Biological Sciences University of the East - Manila Population Ecology Studyof interaction within populations; how it changes through time Study of population in relation to the environment Population  group of individuals occupying a space at a given time Properties of Population  Population Density Natality Mortality Immigration and Emigration  Population Dispersion  Age Distribution Population Density – size of any population in relation to some unit of space; express in terms of individuals or biomass per unit area or volume  population size is the number of individual organisms in a population  Influenced by natality, mortality, migration (emigration and immigration)  life expectancy: length of time an individual is expected to live  Immigration-movement of individuals into an area + Natality – + the production of new Populati - Mortality individuals by on birth, hatching, germination or Density fission - Emigration- movement of individuals out of an area  Population Distribution Patterns or Population Dispersion or Population Spacing – describes how individuals arrange themselves within a population Population Dispersion  Population Dynamics  study of the changes of relative number of organisms in populations and factors explaining the changes  change in size and composition over time Population growth rate  is the increase (or decrease) in the number of individuals in the population during a certain period of time  If immigration and emigration are ignored, a population’s growth rate equals birth rate minus death rate; this is called “natural increase” in the human population r = (b + i) - (d + e) r = population growth rate  if consider migration b = birth rate i = immigration rate d = death rate e = emigration rate Exponential Growth Curve - Unlimited resources - Absence of predation - No disease Exponential Growth The logistic growth model. A small population initially experiences exponential growth. As the population becomes larger, however, resources become scarcer, and the growth rate slows. When the population size reaches the carrying capacity of the environment, growth stops. As a result, the pattern of population growth follows an S-shaped curve.  Carrying Capacity (k):  the number of individuals of a particular species that an environment can support  The maximum population size that can be supported by the available resources  Maximum number of organisms a given area can support  The actual size of the population is usually higher or lower than the carrying capacity below the capacity means birth rate increases above the capacity means population will die or starve  “Booms” and “Busts” About every 10 years both lynx and hare populations have a rapid increase (a “boom”) and followed by a sharp decline (a “bust”)  Limit to Population Growth  Environment limits population growth by altering birth and death rates density-dependent factors density-independent factors Density dependent factors depends on the number of members in a population per unit area influence a population in proportion to its size competition for resources, predation, infectious disease, crowding Density independent factors affect the population regardless of the number of individuals include natural phenomena such as drought, floods, storms, volcanic eruptions, fire, temperature, clear cutting, chemical pesticides, major habitat disruption Age structure A description of how many individuals fit into particular age categories in a population. Age Structure or Distribution Age Structure or Distribution  Urban Sprawling ( urbanization) Migration of a population from populated towns and cities to low density residential development over more and more rural lands  they moving trying to find better areas to live  SOLUTIONS Smart Growth Tools Protection Limits and Preserve existing open space Regulations Buy new open space Limit building permits Buy development rights that prohibit certain types of development on land parcels Urban growth boundaries Greenbelts around cities Public review of new development Taxes Tax land, not buildings Zoning Tax land on value of actual use (such as forest and agriculture) instead of on Encourage mixed use of housing highest value as developed land and small businesses Concentrate development along mass transportation routes Tax Breaks Promote high-density cluster For owners agreeing not to allow certain housing developments types of development (conservation easements) Planning For cleaning up and developing abandoned urban sites Ecological land-use planning Environmental impact analysis Revitalization and New Growth Revitalize existing towns and cities Integrated regional planning Build well-planned new towns and villages within State and national planning cities Can we continue to expand the earth's carrying capacity for humans?  Demography  statistical study of human populations, especially with reference to size and density, distribution, and vital statistics (births, marriages, deaths, etc.).  The annual population growth rate has decreased significantly since 1960 where it was 3.3%.  The current population density of Philippines in 2024 is 397.02 people/km 2, a 1.51% increase from 2023.  The current population density of Philippines in 2023 was 391.12 people/km 2, a 1.54% increase from 2022. The current population density of Philippines in 2022 is 385.20 people/km2, a 1.47% increase from 2021. The population density of Philippines in 2021 was 379.60 people/km2, a 1.51% increase from 2020. The total land area is 298,170 Km2 (115,124 sq. miles)  With about 2 million people added to the population every year, the population is expected to double in about 40 years.  The population density of the Philippines is high, but the distribution of the population is uneven. Parts of Metro Manila have a population density that is more than 100 times that of some outlying areas such as the mountainous area of northern Luzon.  The country’s birth rate remains significantly higher than the world average, as well as the average for the Southeast Asian region. Total Fertility Rate - represents the number of children that would be born to a woman if she were to live to the end of her childbearing years and bear children in accordance with current age-specific fertility rates. Philippines Population History  The first census in the Philippines was held in 1591 and recorded a population of just 667,612 people.  Japan already had a population of 8 million at that time.  The Philippines crossed the 1,000,000 threshold in the mid 18th century and grew to nearly 8 million by 1900.  It has seen steady growth throughout its recorded history until it's impressive population of today.  In addition to the over 100 million Filipinos living in the Philippines itself, there are estimated to be around 10.2 million Filipino people living abroad. Many have moved abroad temporarily to find work, but others have settled abroad permanently.  Given its close ties with America, it is not surprising that the United States is home to the largest group of overseas Filipinos - over 3.5 million.  There are also large Filipino populations in the Middle East (1 million in Saudi Arabia, 822,000 in the United Arab Emirates and 204,000 in Qatar), Malaysia (793,000), Japan (182,000) and Australia (397,000.)  Interestingly, only about 42,000 Filipinos live in Spain, the Philippines' old imperial master.  The Commission on Population and Development (POPCOM) is the central coordinating and policy making body of the Philippine government on population concerns. In 1971, Republic Act 6365, the "Population Act of the Philippines," established the Commission and laid down the government's policies on population. In 1972, Presidential Decree No. 79, the "Revised Population Act of the Philippines," strengthened RA 6365 and reiterated the government's basic population policies. On March 24, 2003 Malacaňang issued an Executive Order 188 attaching POPCOM to DOH. The Commission is the central policy-making, planning, coordinating, and monitoring agency for the Philippine Population Management Program.  THE PHILIPPINE POPULATION MANAGEMENT PROGRAM (PPMP) The goal of the Philippine Population Management Program is to help the country achieve a sustainable population level, structure, distribution and quality in order to empower Filipinos to acquire a better quality of life both within the family and the society at large. The program is guided by certain principles about human life, marriage, family, and environment, as provided for in the Philippine Constitution and embedded in our religious and cultural beliefs. The PPMP has four major policy objectives/strategies: 1. To help couples/parents achieve their desired family size within the context of responsible parenthood and family planning (RH/FP); 2. To reduce maternal mortality, infant mortality and child mortality through improved reproductive health (RH); 3. To reduce the incidence of teenage pregnancy, incidence of early marriage, and the incidence of other reproductive health problems/adolescent health and youth development (AHYD); and 4. To contribute to policies that will assist government to achieve a favorable balance between population distribution, economic activities, and the environment/integration of population and development planning (POPDEV). The Responsible Parenthood and Reproductive Health Act of 2012, also known as the Reproductive Health Law or RH Law, and officially designated as Republic Act No. 10354, is a law in the Philippines, which guarantees universal access to methods on contraception, fertility control, sexual education, and maternal care.