GE ELECT 4 - Module 5 & 6 Flashcards
An ______________ is a structural and functional unit of ecology where the living organisms interact with each other and the surrounding environment.
ecosystem
- It refers to the rate of biomass production.
Productivity
- It is the sequential process through which energy flows from one trophic level to another. The energy captured from the sun flows from producers to consumers and then to decomposers and finally back to the environment.
Energy flow
- It is the process of breakdown of dead organic material. The top-soil is the major site for decomposition.
Decomposition
- In an ecosystem nutrients are consumed and recycled back in various forms for the utilization by various organisms.
Nutrient cycling
A is an ecosystem that is found on land. In terrestrial ecosystems, organisms live in the soil and in the air. Examples of terrestrial ecosystems are forests, grasslands, tundra, and deserts.
terrestrial ecosystem
is an ecosystem where many organisms live together with the environment’s abiotic components. There are many different flora and fauna in this ecosystem. Forests are significant carbon sinks and participate in controlling and balancing the overall temperature of the Earth.
forest ecosystem
- Tropical evergreen forests are found mostly near the equator. They have sparse undergrowth interspersed with clearings.
Tropical evergreen forest
- Tropical deciduous forests are also called the monsoon forests and spread over the region receiving rainfall between 200 cm and 70 cm. Trees of this forest-type shed their leaves for about six to eight weeks in dry summer.
Tropical deciduous forest
- Temperate evergreen forests are found in the United States, Canada, Europe, and Asia, in areas that generally receive between 300 and 900 mm of rain per year and with seasonal temperature extremes ranging from -40 to 20 °C.
Temperate evergreen forest
- The average daily temperatures range between -30°C (-22°F) and 30°C (86°F) with a yearly average of 10°C (50°F). Hot summers and cold winters are typical in this biome. On average, this biome receives 750 to 1,500 millimeters (30 to 59 inches) of rain per year.
Temperate deciduous forest
- The taiga is a forest of the cold, subarctic region. The soil beneath the taiga often contains permafrost—a layer of permanently frozen soil. Coldness is the dominant climatic factor in taiga ecosystems, although a surprising diversity of climates exists.
Taiga
are referred to as those ecosystems where the number of trees is low. These ecosystems mainly consist of grasses, shrubs, and herbs. Grassland ecosystems are commonly situated in both the tropical and temperate regions globally; however, they have distinct variations.
Grassland ecosystems
- are grasslands that are located closer to the equator than prairies. Savannas can receive as much as 120 cm of rain per year. In addition to grass, scattered shrubs and small trees can grow in the savanna.
Savanna
are devoid of trees and are found in cold climates or where rainfall is scarce. These are covered with snow for most of the year. Tundra type of ecosystem is found in the Arctic or mountain tops. Because rainwater cannot soak into the permafrost, there are many shallow ponds and marshy areas of the tundra during the summer.
Tundra ecosystems
exist worldwide and cover about 17 percent of desert areas. These are areas where annual rainfall is usually measured less than 25 mm. Due to fewer trees and land of sand, sunlight intensifies in these ecosystems.
Desert ecosystems
TYPES OF DESERT ECOSYSTEM
- Sand desert
- Rock desert
- Stony desert
- Plateau desert
- Cold desert
is an ecosystem that is found in water. Aquatic ecosystems are home to a wide variety of plants and animals. The two main types of aquatic ecosystems are freshwater ecosystems and marine ecosystems.
aquatic ecosystem
The __________is an aquatic ecosystem that includes lakes, ponds, rivers, streams and wetlands. These have no salt content in contrast with the marine ecosystem.
freshwater ecosystem
- Water bodies that are moving slowly or are still in some places come under lentic. For example, ponds, lakes, pools, etc. Lakes are known as large water bodies and are surrounded by land.
Lentic Ecosystem
- Water bodies that are moving at a fast pace fall under a lotic. For example, streams and rivers. Animals adapt to the stream/river’s current (hooks and suckers to cling to rocks, streamline bodies). Few plants or algae can grow because of the strong currents. Animals rely on seeds and leaves to fall in the water as food.
Lotic Ecosystem
- Environments characterized by soils saturated with water for a long time fall under wetlands.
Wetland Ecosystem
are usually characterized by the presence of salt content. These ecosystems have a higher salt content than the freshwater ecosystem. Moreover, they are known as the largest type of ecosystem on Earth.
Marine ecosystems
VARIOUS HUMAN ACTIVITIES THAT AFFECT AN ECOSYSTEM
- Agriculture
- Deforestation
- Overpopulation and consumption
- Plastic production
- Emission of greenhouse gases and other greenhouse gases
- Destruction of the reefs
- Draining streams/rivers and destruction of critical freshwater aquifer recharge areas (water pollution)
- Overhunting and overexploitation
- Invasive species
commonly known as mahogany
Swietenia macrophylla
commonly known as The cane toad frog
Rhinella marina
An interdisciplinary field of research that seeks to understand the natural world and our relationship to it.
One of the most important properties of living things is that their abundances change over time and space.
ENVIRONMENTAL SCIENCE
THE HUMAN POPULATION OVER TIME
Since we emerged as our own species some 200,000 years ago, we have grown from a few thousands individuals to over 7 billion!
The time it takes our population to double has decreased sharply.
It only has taken about 12 years to go from 6-7 billion people.
We are projected to hit 9 billion near the year 2050.
Estimates say stabilization around 2100. (10.5 billion)
From the first evolution of humans to the beginning of agriculture.
Population density: About 1 person per 130-260 km^2 in the most habitable areas.
Total human population: As low as one-quarter million less than the population of modern small cities.
Average rate of growth: The annual rate of increase is less than 0.00011% per year.
HUNTERS AND GATHERERS
Beginning sometime between 9000 B.C. and 6000 B.C. and lasting until approximately the 16th century.
Population density: Human population increased greatly, about 1 or 2 people/km^2 or more.
Total human population: About 100 million by A.D. 1 and 500 million by A.D. 1600.
Average rate of growth: Perhaps about 0.03% which was high enough to increase the population.
EARLY PRE-INDUSTRIAL AGRICULTURE
Beginning in the 16th century
Total human population: About 900 million in 1800, almost doubling in the next century and doubling again (to 3 billion) by 1960.
Average rate of growth: By 1600, about 0.1% per year, with rate increases of about 0.1% every 50 years until 1950.
THE MACHINE AGE
Beginning in the mid-20th century
Total human population: Reaching and exceeding 6.6 billion.
Average rate of growth: The growth rate of the human population reached 2% in the middle of the 20th century and has declined to 1.2%
THE MODERN ERA
- is the general study of population changes.
Population dynamic
- is a group of individuals of the same species living in the same area or interbreeding and sharing genetic information.
Population
- is all individuals that are capable of interbreeding, and so a species is composed of one or more populations.
Species
- is the statistical study of human populations, and people who study the human population include demographers.
Demography
Factors that drive population growth include:
- Birth rate
- Death rate
- Immigration
- Emigration
Human _____________ is stated as the number of individuals born per year per 1000 in the population.
The population logically escalates if the number of births is more than the number of deaths at any particular time or if the death rate is less or slower in respect to the birth rate.
The formula for calculating crude ___________ is:
Crude Birth Rate (CBR) = (Number of births within a year/Total mid-year population) × 1000
The current birth rate for the Philippines in 2022 is 19.778 births per 1000 people, a 1% decline from 2021.
Birth rate
A crucial reason affecting the growth of the population is the death, or mortality rate.
As the birth of new individuals escalates the population size, deaths decline it. The issues that affect the mortality rate consist of the accessibility and affordability of quality health care and daily life practices.
The formula for calculating Crude Death Rate is:
Crude Death Rate (CDR) = (Number of deaths within a year/Total mid-year population)× 1000
Death rate
(moving into the place/country) is the movement of individuals into a population from other areas.
Immigrants contribute to population growth because of both their own numbers and their above-average fertility. Most of those who immigrate are working-age adults.
Immigration
(exiting from a place/country) is the movement of individuals out of a population.
A number of factors, such as running away from war, searching and finding good education, pursuing a career, searching new jobs or union with family members, results in emigration.
When an individual emigrates from a nation, its population declines gradually.
Emigration
attract people towards a certain place/country. Example of pull factors include; better job opportunities, social securities, better health facilities and improved education systems etc.
Pull factors
force people to leave the place/country. Examples of push factors include; lack of social harmony and peace, increased conflict, war, poor education systems, poor job opportunities, lack of adequate resources etc.
Push factors
- An estimate of the
average number of childrenthat eachwomanin a populationwill bearthroughout her childbearing years.
Total fertility rate (TFR)
- The
total fertility rate required to offset the average number of deathsin a population in order to maintain the current population size. - tends to be higher in developing countries because mortality among young people tends to be higher.
Replacement-level fertility
- The average
number of years that an infant born in a particular yearin a particular country can be expected to live, given the current average life span and death rate in that country.
Life expectancy
- The
number of deaths of childrenunder 1 year of age per 1,000 live births.
Infant mortality
- The
number of deaths of childrenunder age 5 per 1,000 live births.
Child mortality
- A visual representation of the
number of individuals within specific age groupsfor a country, typically expressed for males and females. - describe how populations are distributes across age ranges
Age structure diagram
- An age structure diagram that is widest at the bottom and smallest at the top, typical of developing countries.
Population pyramid
- Continued population growth after growth reduction measures have been implemented.
Population momentum
occurs in a population that has many young people and a high death rate at each age—and therefore a high birth rate, characteristic of a rapidly growing population and also of a population with a relatively short average lifetime.
The pyramid age structure
occurs where the birth rate and death rate are low and a high percentage of the population is elderly.
A column shape
occurs if some event in the past caused a high birth rate or death rate for some age group but not others.
A bulge
occurs when a population has more older than younger people.
An inverted pyramid
- studied human population growth and said was growing faster than Earth’s resources
Thomas Malthus (late 1700’s)
Malthus examined the relationship between population growth and resources in one of his works. He then proposed the Malthusian theory of population where he said that the population grows exponentially and the food supply grows arithmetically and that a balance between the two can be established through positive and preventive checks.
MALTHUSIAN THEORY OF POPULATION
HUMAN IMPACTS ON ECOSYSTEM
Modern scientists use there observations and predictions when describing ecosystem’s carrying capacity
Current human population is about 7 billion.
Not sure what the limit (carrying capacity) is for size of human population.
Maximum number of individuals an ecosystem can support
Carrying Capacity
include coal, natural gas, oil, and nuclear energy. Once these resources are used up, they cannot be replaced, which is a major problem for humanity as we are currently dependent on them to supply most of our energy needs.
Non-renewable resources
- resources that can be used up or
can replenish themselves over time(e.g. wind energy, solar, lumber, etc.)
Renewable resources
