Ecol Finals Flashcards
types of ecosystem
natural and artificial
is a natural unit consisting of all plants, animals & microorganism
natural ecosystem
are created by human beings where management, balance of the nature is disturbed regularly
artificial ecosystem
a place where plants & animals are dependent upon one another
natural ecosystem
importance of ecosystem
*Provide food & fiber, fuel, wood & grass
*Supply medicines
*Regulates our environment in controlling risks from landslides, floods & other catastrophic events
a land-based community of organisms and the interactions of biotic and abiotic components in a given area
terrestrial ecosystem
Five (5) Fundamental Steps In The Operation Of The Ecosystems
- reception of energy
- production of organic materials
- consumption
- decomposition of organic compounds
- transformation to suitable forms
Strength of Natural Ecosystems
- efficiency
- diversity
- self-sufficiency
- self-regulation
- resiliency
*related to the flows of energy production
*tend to be economical in capturing and using rainfall & in mobilizing & cycling nutrients
efficiency
use solar energy to produce organic material
producers
use the plants as food which supplies them energy
primary consumers
feed on the herbivores and derive energy for their sustenance and growth
secondary consumers & tertiary consumers
*both above ground & in the soil
*provides checks & balances, nutrient availability & checks on disease outbreaks
diversity
requiring only inputs of sunlight and rainfall
self-sufficiency
a self-sufficient ecosystem can
recycle nutrients
maintain biodiversity
regulate populations
provide essential services
ability of communities & ecosystems to withstand, learn from, & adapt to the impacts of a problem
resiliency
Eight (8) General Ecological Principles
- adaptation
- behavior
- diversity
- emergent properties
- energy flow
- growth and development
- limits
- regulation
the way a life system looks or behaves is not random or accidental; rather it is the result of changing to survive in a dynamic environment
adaptation
living systems evolve behavioral responses to stress and disturbances to enhance survival
behavior
changes in environmental conditions over time have led to variety within each level of organization
diversity
when different levels of organizations are functioning together, new properties are created that were not operational at lower levels
emergent properties
energy cannot be created or destroyed but it can change form. energy quality is always degraded through transformation
energy flow
as organisms and systems increase in size, changes that occur allow survival. growth rate slows as maximum capacity is net.
growth and development
there are limits to how much stress can be tolerated by living systems
limits
energy is spent if a signal is sent to increase or decrease some function to maintain balance
regulation
“Evolution, Life History Patterns, Natural Selection, Survival, Predator-Prey Interactions” is the associated concept of
adaptation
“Reproduction, Predator- Prey interactions, Dispersal, Survival (humans and other animal species), Pest Control (exotics, nuisance animals) Harvesting” is the associated concept of
behavior
“Competition, Land-Use Practices, Genetics, Survival, Fragmentation” is the associated concept of
diversity
“Complexity, Synthesis, Teamwork, Government” is the associated concept of
emergent properties
“Thermodynamics, Food Chains, Tropic Levels, Heat Exchange” is the associated concept of
energy flow
“Succession, Reproduction, Population Dynamics, Competition” is the associated concept of
growth and development
“Sustainability, Conservation, Disease, Natural Disaster, Agriculture, Pollution” is the associated concept of
limits
“Feedback Loops, Organismal Systems, Cybernetics” is the associated concept of
regulation
Three (3) Fundamental Concepts of Productivity of an Ecosystem
Standing crop
Material removal
Production rate
abundance of organisms existing in the area at any one time
Standing crop
materials removed from the area per unit time
Material removal
amount of material formed by each link in the food chain per unit of time per unit area or volume is the production rate
Production rate
Three (3) steps overall strategy to the production of crops relying heavily on ecological principles
- Build internal strengths into the agricultural ecosystem
- Use routine ecologically sound practices during the season to keep plants healthy
- In an unanticipated problem arises, use the most compassionate reactive (therapeutic) means possible to deal with it
Applying Ecological Principles in the Farm
- Keep the soil covered all the time
- Stir, not invert the soil
- Recycle and utilize available local resources
- Diversity is the Law of Nature
- Natural, not chemical
Farm practices that increase the utilization of solar energy
- Planting cover crops
- Perennial vegetation
- Mixed cropping
- Timing of planting
- Proper spacing
Humans tend to adopt strategies and goals that are in conflict with natural processes
Pest management of modern agriculture
Ecologists’ perspective that “pests are not problems but are symptoms that there is ecological imbalance in the system”
the approach would be to manage the farm to create or restore ecological balance in the system
Pest management of sustainable agriculture
a system is considered effective if there is high diversity of plants, animals, and other life forms both above and below ground.
biodiversity
three types of diversity
- Genetic diversity
- Species diversity
- Ecological diversity
-variation in genes within a species
-essential for the survival and adaptability of a species
-the genetic diversity of a particular crop maybe increased by planting more than one variety
genetic diversity
stands for the number (species richness) and abundance of species (species evenness)
species diversity
-variety of ecosystems within a region or on a global scale
-encompasses different types of habitats, communities and ecological processes
ecological diversity
Ecologically sound management practices
- crop rotation
- multiple cropping
- planting of locally adapted & resistant varieties
- spacing of crops and row orientation
- mulching (living or non-living materials)
- trap and decoy crops
- water management
- field sanitation
Prevents build up of insect pests and diseases & restores soil fertility
crop rotation
-the intensification of cropping in time and space dimension
-the growing of two or more crops in the same field in a year
multiple cropping
useful for suppression of weeds, insect pests, & some plant diseases
mulching
attract & more preferred by pests due to strong odor & colorful flowers
trap and decoy crops
very effective in reducing the population of insect pests, snails, & weeds
water management
to prevent introduction of pest in the farm, prevent the spread of pests, & manage the pest in the farm
field sanitation
FIVE-STEP EVALUATION PROCESS BEFORE CONVERSION
- Visualize
- Evaluate
- Educate
- Plan
- Act
3 COMPONENTS EVOLUTIONARY METHODS TO CONVERSION
- Increased efficiency
- Substitution
- Redesign
The usual conventional systems are altered to reduce the use of costly and scarce resources
Increased efficiency
Purchased chemical inputs & practices (environmentally degrading) are replaced by more environmentally benign inputs & practices
Substitution
Causes of problems are recognized, prevented, and solved internally using management solutions rather than the application of external input
Redesign
APPROACHES TO CONVERSION
- Vertical conversion
- Horizontal conversion
The use of conventional inputs such as chemical fertilizers and/or practices is gradually reduced throughout the farm.
Vertical conversion
Complete conversion of a portion of the farm to sustainable agriculture, while conventional farming is still being practiced in the remaining portion of the farm.
Horizontal conversion
SOME CONSIDERATIONS IN THE CONVERSION PROCESS
- BUILD UP INTERNAL RESOURCES
- APPROPRIATE TILLAGE AND
SOIL REHABILITATION - CHOICE OF CROP VARIETIES AND
ANIMAL BREED - PEST MANAGEMENT
- MARKETING
- LABOR REQUIREMENTS
- YIELD PREDICTION
