covers both the physical sciences (physics, chemistry, biology, geology, geography, resource technology, and engineering) and social sciences (resource conservation and management, demography, economics, politics and ethics) - Miller, 1994

sum total of all the external factors acting on an organism or community of organisms which includes the living and nonliving elements.

oikos, meaning

It is the study of the interactions of organisms with one another and with their physical and biological environment.

Levels of Organization

longest level of organization single organism independently function can reproduce

group of similar individual usually of a given species consists of organisms that feed and move together and interbreed among themselves to reproduce

populations of different species living together and sharing the same habitat

unit of nature consistency of more than a community of living organisms and their interaction with non-living ones

total of all the ecosystems on Earth

Characteristics of Population

degree of crowdness of population

number of individuals or the total population per unit space

biomass per unit space

Two types of Population density

Three types and dispersion

distribution of organisms over the space where they are found

most common type of pattern

rare in nature, occuring where the soil is generally rich so that the plants can grow and thrive anywhere.

distribution is found in artificial cultivated areas such as orchards.

birth rate, number of new individuals produced in the population for a period of time

death rate, number of deaths in a given period of time

population according to the age bracket

theoretical capacity to produce the max number of offsprings in ideal conditions

Properties of Community

attained by a species in a community by virtue of a greater number of individuals or by size.

opposite of dominance no single species has a greater number or biomass of other relative importance than other species in the community

sequence of eating and being eaten each level or link in the chain is called trophic level

plants and photosynthetic organisms occupies the first level

plant feeders occupy the second level

feed on herbivores and other consumers occupy different levels according to what they feed

Food chain levels

consists of all the food chains in a single ecosystem. Each living thing in an ecosystem is part of multiple food chains.

nutrients move through the ecosystem in cycles called?

The following are the classification of biogeochemical cycles

Includes Carbon, Oxygen, Nitrogen and Water Cycle

Includes Sulphur, Phosphorous, Rock Cycle, etc.

cycle that involves the continuous circulation of water in the Earth-atmosphere system. Of the many processes involved in the water cycle, the most important are evaporation, transpiration, condensation, precipitation, and runoff.

Stage of water cycle

It is a process where water at the surface turns into water vapors.

As water vaporizes into water vapor, it rises up in the atmosphere. At high altitudes the water vapor changes into very tiny particles of ice /water droplets because of low temperature.

process where ice directly converts into water vapors without converting into liquid water

The clouds (condensed water vapors) then pour down as ____________ due to wind or temperature change.

process similar to evaporation where liquid water is turned into water vapor by the plants.

the process where water runs over the surface of earth.

Any water that doesn't run directly to bodies of water or get quickly evaporated, will be absorbed by plants and soil, where it may be driven deeper to the earth.

process that moves carbon between plants, animals, and microbes; minerals in the earth; and the atmosphere.

Law of energy

states that energy is neither created nor destroyed

states that as energy is transformed, it degrades or diminishes.

Percentage of nitrogen in the atmosphere

Nitrogen cycle

the process of conversion of nitrogen from the gaseous state, N2, to the usable ammonia, NH3 and nitrate, NO3

involves the breakdown of organisms and their proteins and nucleic acids are further broken down into amino acids. The amino acids are converted into carbon dioxide, water and ammonia, with a release of energy. The ammonia is the usable form of nitrogen that plant roots may absorb.

is where bacteria such as Nitrosomonas use ammonia to produce their energy needs by converting it to nitrous acid and water, and then to nitrate and nitrite with a yield of energy.

the process by which nitrogen is returned to the atmosphere. Denitrifying fungi and bacteria perform the process to acquire oxygen such as Pseudomonas that convert nitrates into gaseous nitrogen in an oxygenated environment.

when there is not enough of a certain nutrient in the environment, the growth of the organism that needs that nutrient will be severely limited

too much of any nutrient will likewise limit growth

states that organisms have specific ranges of minimum and maximum limits of tolerance that affect their survival, growth, and reproduction.

Environmental principles

RELATIONSHIPS BETWEEN THE DIFFERENT COMPONENTS OF THE ENVIRONMENT AND ECOSYSTEM

interaction between two species where both are benefited.

two species or two individuals of same species strive to obtain the same limited resource.

wherein predator eats the prey.

wherein the host provides nourishment to the parasite. This interaction could cause physical and physiological effects to the host.

wherein a commensal attaches itself to the host while it is neither helped nor harmed.

one organism is inhibited while the other is not affected.

Steps in Phosphorous Cycle

is a biogeochemical process that involves the movement of phosphorus through the lithosphere, hydrosphere and biosphere.

It is a functional unit of nature consisting of more than a community of living organisms (biotic factors) and their interaction with n

Major Types of Natural Ecosystems

the main nutrient source for the plants/producers in this ecosystem is the soil.

Example of Terrestrial ecosystem

ecosystem where the average precipitation is low and evaporation rates are high. It is further classified into three types: (1) tropical, (2) temperate, and (3) cold

undisturbed areas with an average precipitation of 750 mm or more a year tend to be covered with forests.

Desert – ecosystem where the average precipitation is low and evaporation rates are high. It is further classified into three types:

the main nutrient source for the plants/producers in this ecosystem is the water.

Example of aquatic ecosystem

ecosystems whose physical nature is dominated by the presence of water and supports a distinct set of producers (plants) and animals.

as distinguished from the freshwater, it has a higher level of salinity, usually at 35 parts per thousand.

Forest – undisturbed areas with an average precipitation of ________ or more a year tend to be covered with forests.

Marine ecosystems – as distinguished from the freshwater, it has a higher level of salinity, usually at ____________

Natural Freshwater Ecosystems

Man-made ecosystem

A semi-natural or modified natural system managed by humans for food and agricultural production purposes.

An ecosystem that has been modified for agricultural use is called an?

are the environmental benefits resulting from physical, chemical and biological functions of healthy ecosystems and include market goods produced from ecosystems (ex: food, fibre, fuel, fresh water, genetic resources, etc.), the benefits from ecosystem processes, (ex: nutrient cycling, climate regulation, water purification, waste treatment, pollination, etc.) and non-material benefits (ex: aesthetic values, recreation, etc.).

is a way of understanding the interactions of the different factors in the field, which are directly and indirectly affecting the growth and development of the rice plant.

It is a way of putting together what we are studying and placing into a process useful for decision-making. It can be done by weekly monitoring and considering different factors such as:

Determine weed density as ?

Developing a Sustainable Agro-ecosystem