Intro to Environmental Science
Biocentric Preservation
The belief that all organisms have intrinsic value
Environment
Physical, social and cultural conditions that surround an organism
Sustainable Development
Meeting the needs of the present without compromising the ability of the future generations to meet their own needs
Utilitarian Conservation
Uses resources for the greatest good for the greatest number of people for the longest time
Atom
The smallest particle to exhibit the characteristics of an element
Molecules
Combination of 2 or more of the same atom (ex. O2)
Compound
Combination of 2 or more different atoms (ex. H2O)
Conservation of Matter
In any chemical reaction, matter changes form; it is neither created nor destroyed
Critical Thinking
An ability to evaluate information and opinions in a systematic, purposeful, efficient manner
Potential Energy
Energy that is in storage (ex. Water stored behind a dam)
Kinetic Energy
Energy at work (ex. a car in motion)
First Law of Thermodynamics
Energy is conserved; it is neither created nor destroyed
Second Law of Thermodynamics
With each successive energy transfer or transformation in a system, less energy is available to do work (some energy is lost after each transfer)
Photosynthesis
The biochemical process by which green plants and some bacteria capture light energy and use it to produce chemical bonds. Carbon dioxide and water are consumed and oxygen and simple sugars are produced (6CO2 + 6H2O –> C6H12O6 +6O2)
Cellular Respiration
The process in which a cell breaks down sugar or other organic compounds to release energy used for cellular work; may be anaerobic or aerobic depending on oxygen availability (6O2 + C6H12O6 –> 6CO2 + 6H20)
Nitrogen Gas Cycle
The cycle of Nitrogen in the environment (ground to air)
Phosphorous Cycle (solid)
Starts with Phosphate rocks, Phosphate gets into water supply (via farm runoff, sewage, use of phosphate soaps), Phosphate reaches ocean and stimulates excessive growth, eventually back to rock.
Cells
Fundamental unit of life; membranes enclose organelles; enzymes facilitate chemical reactions
Producers
Produce food from inorganic compounds using an external energy source
Biomass
Total mass of all organisms in a population or area (rainforests and estuaries have highest biomass)
Productivity
The amount of biomass produced in a given area during a given time
Consumers
Feed on other organisms or their remains
Herbivore
Organisms that eat only plants
Carnivore
Organisms that mainly prey on animals (meat eaters)
Omnivore
Organisms that eat both plants and animals
Scavenger
An organism that eats the remains of other animals
Decomposer
Fungus or bacterium that breaks complex organic material into smaller molecules
Detritivore
Organisms that consume organic litter, debris and dung
Food Chain
A linked feeding series
Food Web
A complex, interlocking series of individual food chains in an ecosystem
Trophic Levels
Feeding levels in a food chain (producer vs consumer; first level, second level, etc.)
Species
All the organisms genetically similar enough to breed and produce live, fertile offspring in nature (ex. Asian Elephants)
Population
All the members of a species that live in the same area at the same time (ex. All Asian Elephants in India)
Biological Community
The populations of plants, animals and microorganisms living and interacting in a certain area at a given time (ex. The Asian Elephants in India plus everything they eat, and their predators)
Ecosystem
A specific biological community and its physical environment interacting in an exchange of matter and energy (ex. The Asian Elephants in India eating the plants)
Adaptation
Physical changes that allow organisms to survive in a given environent
Biotic Potential
The maximum reproductive rate of an organism, give unlimited resources and ideal environmental conditions
Carrying Capacity
The maximum number of individuals of any species that can be supported by a particular ecosystem on a long-term basis
[has to have “on a long-term basis” to distinguish between overshoot]
Dieback
A sudden population decline; also called population crash
Ecological Niche
The functional role and position of a species in its ecosystem, including what resources it uses, how and when it uses those resources, and how it interacts with other species (ex. Panda Bears eating bamboo)
Environmental Resistance
All the factors that limit population growth (ex. lack of food, climate, predation, disease)
Evolution
A theory that explains how random changes in genetic material and competition for scarce resources cause species to change gradually
Exponential Growth
A growth that is slow at first but that sharply increases (represented by a J-Curve)
Habitat
The place or set of environmental conditions in which a particular organism lives
Invasive Species
Organisms that thrive in new territory where they are free of predators, diseases or limitation of resources that may have controlled their population in their native habitat (ex. Zebra Muscles, Asian Beetles)
Keystone Species
A species whose impact on the community or ecosystem are much larger and more influential than would be expected from mere abundance (ex. Krill, Prairie Dogs)
Natural Selection
The mechanism of evolutionary change in which environmental pressures cause certain genetic combinations in a population to become more abundant; genetic combinations best adapted for the present environmental conditions tend to be predominant
Overshoot
A sharp increase in population that usually results in a dieback because it is way over the carrying capacity
Resource Partitioning
In a biological community, various populations sharing environmental resources through specialization, thereby reducing direct competition (similar to ecological niche (the panda bears))
S-Curve
A curve that depicts logistic growth; a J-Curve that levels off at the end and then has an “S” shape
Resource Partitioning
In a biological community, various populations sharing environmental resources through specialization, thereby reducing direct competition (similar to ecological niche (the panda bears))
S-Curve
A curve that depicts logistic growth; a J-Curve that levels off at the end and then has an “S” shape
Secondary Succession
A previous community is replaced after a disturbance
Primary Succession
No previous living species
What are the 4 community properties?
Abundance: the number of individuals
Diversity: the number of species
Complexity: the number of species at each trophic level
Stability: the ability to resist change or recover from change
Tolerance Limits (Limiting Factors)
Chemical or physical factors that limit the existence, growth, abundance, or distribution of an organism
Crude Birth Rate
The number of births in a year per 1000 (the human population growth curve)
Crude Death Rate
The number of deaths a year per 1000
Demographic Transition
A pattern of falling death and birth rates in response to improves living conditions (usually leads to rapid growth then stabilized growth)
Total Fertility Rate
The average number of kids born to a woman
Zero Population Growth
A condition in which births and immigration in a population just balance deaths and emigration
Biodiversity
The genetic, species and ecological diversity of the organisms in a given area
Biome
Ecosystems with similar climate, growth patterns and vegetation
Deforestation
Removing trees from a forest
Endangered Species
A species considered to be in imminent danger of extinction
Extinction
The irrevocable elimination of species; can be a normal process of the natural world as species outcompete or kill off others or as environmental conditions change
Fragmentation
Disruption of a habitat into small, isolated sections (ex. if a road is built through a forest, it fragments that habitat)
Habitat Conservation Plan
Part of the U.S. Endangered Species Act of 1973 which also includes recovery plans, private land and critical habitat issues, and minimum viable populations
Minimum Viable Population
The number of individuals needed for long-term survival of rare and endangered species
Overharvesting
Harvesting so much of a resource that it threatens its existence
Threatened Species
While still abundant in parts of its territorial range, this species, has declined significantly in total numbers and may be on the verge of extinction in certain regions or localities
Vulnerable Species
Naturally rare organisms or species whose numbers have been so reduced by human activities that they are susceptible to actions that could push them into threatened or endangered status
Clear Cutting
Cutting every tree in a given area, regardless of species or size; an appropriate harvest method for some species; can be destructive if not carefully controlled
Corridors
Strips of natural habitat that connect two adjacent nature preserves to allow migration of organisms from one place to another
Debt for Nature Swaps
Forgiveness of international debt in exchange for nature protection in developing countries
Desertification
Denuding and degrading a once fertile land, initiating a desert-producing cycle that feeds on itself and causes long term changes in the soil, climate and biota of an area
Ecotourism
A combination of adventure travel, cultural exploration and nature appreciation in wild settings
Monoculture Forestry
Intensive planting of a single species; an efficent wood production approach, but one that encourages pests and disease infestations and conflicts with wildlife habitat or recreation uses
Old Growth Forest
Forests free from disturbance for long enough (about 150-200 years) to have mature trees, physical conditions, species diversity and other characteristics of equilibrium ecosystems
Poaching
Hunting wildlife illegally (ex. Elephants for their tusks)
Rotational Grazing
Confining grazing animals in a small area for a short time to force them to eat weedy species as well as the more desirable grasses and forbes
Selective Cutting
Harvesting only mature trees of certain species and size; usually more expensive than clear cutting but less disruptive for wildlife and often better for forest regeneration
Wilderness
Public land owned by the federal government that has undeveloped land meaning there is no taking of resources form it (oil, logging, grazing)
Wildlife Refuges
Public land owned by the federal government that has permanent habitat and can be developed (oil, logging, grazing)
Contour Plowing
Plowing horizontally along the elevation lines on a hill
Cover Crops
Plants, such as rye, alfalfa or clover, that can be planted immediately after harvest to hold and protect the soil
Famines
Acute food shortages characterized by large-scale loss of life, social disruption and economic chaos
Food Security
The ability of individuals to obtain sufficient food on a day-to-day basis
Genetically Modified Organisms (GMOs)
Organisms created by combining natural or synthetic genes using the techniques of molecular biology
Genetic Engineering
Laboratory manipulation of genetic material using molecular biology
Green Revolution
Dramatically increased agricultural production brought about by “miracle” strains of grain (corn, wheat); usually requires high inputs of water, plant nutrients and pesticides
Reduced Tillage Systems
Farming methods that preserve soil and save energy and water through reduced cultivation; includes minimum till, conserve-till, and no-till systems
Salinization
A process in which mineral salts accumulate in the soil, killing plants; occurs when soils in dry climates are irrigated profusely
Soil
A complex mixture of weathered rock material, partially decomposed organic molecules, and a host of living organisms
Sustainable Agriculture
Ecologically sound, economically viable, socially just agricultural system. Stewardship. soil conservation, and integrated pest management are essential for sustainability
Topsoil
The first true layer of soil; layer in which organic material is mixed with mineral particles; thickness ranges from a meter or more under virgin prairie to zero in some deserts
Waterlogging
Water saturation of soil that fills all air spaces and cause plant roots to die from lack of oxygen a result of overirrigation
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