Environmental Science
How is a populations growth rate most accurately determined?
(CBR + Im) - (CDR + EM) / 10
If the global population has a CDR of 18 and a CBR of 35, this would result in a growth rate of ___
CBR - CDR / 10 = % 35 - 18 / 10 = 1.7%
in a discussion on the relationship between a community complexity and stability, a forester with the FIsh and Wildlife Service points out that while forests tend to have high __, communities in the grasslands would have higher ___
complexity stability
what are descriptions of the boreal forest?
consist of cone bearing evergreen trees that keep their needles year round to survive long and cold winters boreal forest- coniferous trees, such as firs and spruce
what are the populations of lynx and hare in canada the classic example of?
cyclic population fluctuations two distinctive humps with a small patch of overlap
If biotic potential is lower than environmental resistance, a population will
decline biotic potential- maximum rate at which the population of a given species can increase when there are no limits on its rate of growth environmental resistance- all of the limiting factors that act together to limit the growth of a population
What is an environmental effect of bycatch?
depletes species that play an important role in oceanic food webs and depletes species other than the ones that are being used by humans bycatch- the unwanted marine animals that are caught during commercial fishing
What are two areas having the lowest net primary productivity/km2?
desert open ocean
what are the human impacts on freshwater systems that were the primary contributors to the disastrous conditions following Hurricane Katrina in 2005?
destruction of wetlands deforestation concrete keeps the water from being absorbed
enclosing a school of fish with a large net is known as what?
drift net fishing- catching fish in huge nets that drift the water
what is the current associated with ENSO events?
el nino- prevailing tropical winds blowing westward that weaken or reverse normal air flow
vegetarianism is often cited as a partial solution to the growing problem of deforestation and other types of habitat destruction as the human population grows. What is the reason for this?
eliminates the middle process (the livestock which takes up more land for grazing and processing, etc)
what is required for the functioning of an ecosystem?
energy flow water sunlight the chemical cycles
In 2002, Peter and Rosemary Grant studied a population of Darwins finches on one of the Galapagos Islands that feed on seeds of various sizes. After a drought that caused only large seeds to be available for the birds, they found that natural selection favored those birds that had larger beaks and bodies. Once the rains returned, smaller seeds became much more abundant. However, natural selection favored those birds with smaller beaks and bodies. What process is the best interpretation of this scenario?
evolution- change in the genetic makeup of a population of a species in successive generations, and if it continues long enough it can lead to a new species; populations evolve, not individuals)
what causes large algal blooms known as red tides
excess nitrogen causes explosive growth of toxic microscopic which poisons fish and marine animals
what are the problems associated with the Sanctuary Approach to protecting individual species?
extinction and depletion
passenger pigeons were once so abundant that they could literally darken the sky when a flock passed over. However, excessive hunting has resulted in them no longer being found anywhere on earth. This is known as what?
extinction-complete disappearance of a species from earth; it happens when a species cannot adapt and successfully reproduce under new environmental conditions or when it evolves into one or more species
which of the below has been utilized in both India and China to attempt to reduce population growth rates?
family planning programs
Three quarters of the wood harvested in developing countries is used for what purpose?
fuel
The breakup of Pangea as a result of plate tectonics was an event that spurred speciation. Organisms were first ___ than as they adjusted to new conditions they become ___
geographically isolated- separation of the populations of a species for long times into different areas re productively isolated- long term geographic separation of members of a particularly sexually reproducing species
As one climbs a mountain, the elevation changes cause a change in biomes. What best describes the changes in biome types caused by elevation?
gets colder less vegitation/life
which biomes, when converted to agricultural use, can rarely ever recover to its original state due to very low nutrients in the soil?
grasslands tropical rain forests
An increase of greenhouse gases from burning fossil fuels warms the troposphere, causing permafrost to melt releasing additional greenhouse gases into the atmosphere. We would consider this process to be a ___
green house effect- natural effect that releases heat in the atmosphere (troposphere) near the earth surface; water vapor, carbon dioxide, ozone, and other gases in the lower atmosphere absorb some of the infrared radiation (heat) radiated by the earth surface; their molecules vibrate and transform the absorbed energy into longer wavelength infrared radiation (heat) in the troposphere; the average temperature of the troposphere is gradually increasing
what are four ways in which we can manage forests more sustainably and reduce our demand for forest products?
grow timber on long rotations stop old growth logging selective logging protect forests with large biodiversity
what are the essential components of successful nature reserves?
habitat corridors buffer zones
The giant panda is prone to ecological and biological extinction because of what 4 reasons?
habitat loss low birth rate highly specialized diet small realized niche- parts of the fundamental niche of a species that are actually used by a species)
why are population biologists concerned about introduced species such as kudzu vine in North America?
have no natural predators harm native species
what is the primary reason for the very rapid growth of the human population since the industrial revolution?
healthcare and technology that lowered death rates industrial-medical revolution- use of new sources of energy from fossil fuels and later from nuclear fuels, and use of new technologies, to grow food and manufacture products
What do most extinction experts believe will be the cause of biodiversity loss increasing over the next 50 to 100 years?
human activities
sale of exotic pets, decorative plants, endangered species parts, and use of animals for bushmeat are all examples of which threat to biodiversity?
human activities
what is the primary threat to national parks?
human activities
logging, mining, building of roads, and urban development are all examples of which primary threat to biodiversity?
human activities overuse of natural resources
As pollution levels in streams rise, many aquatic insects such as the mayfly quickly disappear. For this reason, many aquatic insects are studied intensively because they are this type of species:
indicator species- species that serve as early warnings that a community or ecosystem is being degraded
what is the first significant change that occurs in a country undergoing demographic transition?
industrialization begins food production rises death rates drop birth rates remain high demographic transition- hypothesis that countries, as they become industrialized have declines in death rates followed by declines in birth rates
what is the indicator best reflecting the availability of overall health care and nutrition of a country?
infant mortality rate- number of babies out of every 1000 born each year who die before their first birthday
A wooden log that weighs 1.00 kg is placed in a fire place. Once lit, it is allowed to burn until there are only traces of ash left, weighing .04 kg. Which of the following best describes what has happened to the matter?
it was transferred into the atmosphere as gas and smoke
Bees play a critical ecological role in their community by pollinating plants. What would a bee considered to be?
keystone species- species that play roles affecting many other organisms in an ecosystem
what is a description of a biome?
large terrestrial regions characterized by similar climate, soil, plants, and animals biome- terrestrial reigons inhabited by certain types of life, especially vegitation ex. deserts, grasslands, forests
hurriances, floods, tornados, and climate change could be best thought of as __ affecting a populations size
negatively
which of the natural cycles does NOT include an atmospheric component?
nitrogen
List 4 threats to coral reef ecosystems
ocean warming acidification algae growth due to runoff soil erosion
what are four examples of tragedy of the commons?
overfishing deforestation poaching overharvesting tragedy of the commons: depletion or degradation of a potentially renewable resource to which people have free and unmanaged access;
what is the current idea regarding swapping debt for nature?
participating countries act as custodians of protected forest reserves in return for foreign aid/debt relief
what is the term for the point in which the number of births worldwide would become stable?
peak child- the number of children born each year is at its peak; same amount of children each year
list four degradation to the environment exclusively caused by anthropogenic activities
pollution deforestation toxic sources in water overfishing
what is the primary reason for the decline of global commercial fish caught in the recent years?
populations of fish species have been depleted
what stage of demographic transition has Europe and the US entered?
postindustrial the order of demographic transition is preindustrial, transitional, industrial, and postindustrial
An early loss survivorship curve is most indicative of a ___ species, while a late loss curve is indicative of a __ species
r- many small offspring K- small number of larger offspring
which ecosystems are ranked as the most productive ecosystems in the world?
rainforests temperate deciduous
the invasive zebra mussels, growing under idea conditions after introductions into Lake Michigan, will most likely experience ___
rapid growth and no predators invasive species- species that migrate into an ecosystem or are deliberately or accidentally introduced into an ecosystem by humans
what four changes would result in an area that was recently clear cut?
reduced biodiversity leaves large openings destroys/fragments wildlife habitats disrupts ecosystem processes
what is one effect of our overgrazing in our natural rangelands?
reduces grass cover invasion of exposed land
In the coniferous forest of Oregon, eight species of woodpeckers coexist. The fifth species nests only in fir trees that have been dead for at least 10 years. The sixth species also nests in fir trees, but only in live or recently dead trees. The two remaining species nest in pine trees, but each selects trees of different sizes. What is this pattern an example of? `
resource partitioning- process of dividing up resources in an ecosystem so that species with similar needs (overlapping ecological niches) use the same scare resources at different times, in different ways, or in different places
Natural capital consists of __ and __
resources and services natural capital- natural resources and natural services that keep us and other species alive and support our economies
what are characteristics of second growth forests?
results from natural secondary succession removed by humans by clearcutting/natural forces second growth forests: stands of trees resulting from secondary ecological succession
converting a midwestern farm back to original prairie grassland would be an example of:
secondary succession- ecological succession in an area in which natural vegitation has been removed or destroyed but the soil is not destroyed
the method of forest harvesting in which trees are harvested individually from a diverse forest is known as what?
selective cutting- cutting of intermediate-aged, mature, or diseased trees in an uneven aged forest stand, either singly or in small groups; this encourages the growth of younger trees and maintains an uneven aged stand
how do parasites differ from conventional predators?
smaller they will rarely kill the host parasite- consumer organism that lives on or in and feeds on a living plant or animal known as the host over an extended period; the parasite draws nourishment from and gradually weakens the host, but may or may not kill it
what combination of processes can change global species biodiversity?
speciation (forming of new species) and extinction
what is species richness?
species richness- number of different species contained in a community; variety of different animals
seasonal overturns in lakes is important because it mixes stratified layers, redistributing dissolved oxygen and nutrients. When does this phenomena occur?
spring and fall
what is the primary limiting factor for producers in the Euphotic zone of the ocean?
sunlight Euphotic zone- upper layer of a body of water through which sunlight can penetrate and support photosynthesis
what soil horizons is most responsible for limiting plant growth?
surface layer O soil horizon- horizontal zones that make up a particular mature soil
how do algal blooms reduce productivity in a water body?
takes up dissolved oxygen blocks sunlight
what biomes have the ideal temperatures and soil for agriculture?
temperate grasslands temperate deciduous forest
the climate of an area is determined by which factors?
temperature precipitation
what part of a cyclic population diagram best depicts competition between two species for a given resource?
the area where the humps overlap
biogeochemical cycles illustrate what?
the conversion of energy biogeochemical cycles the conservation of matter
at which trophic level are birds that consume ticks that feed on herbivorous mammals?
third trophic level plants --> mammal --> ticks --> birds
what are economic services provided by forests?
timber medicines recreation fuel
dragging huge nets across the bottom of the ocean which are weighted down to harvest benthic fish and shellfish is known as
trawler fishing
forests supply us with many vital ecosystem services. Currently, which one is recieving the most attention because of global climate change occurs?
tropical rainforest
Organisms live within a range of tolerance that determines where they live. What examples show a species tolerance?
trout live within a narrow band on temperatures in rivers
which biome is characterized by subfreezing temperatures much of the year, low precipitation rates, and the formation of permafrost?
tundra
tundra vs taiga ``
tundra = less rain, more permafrost
under normal conditions, strong trade winds push __ surface water __ South America. El Nino is the __ of these conditions
warm westward reverse
riparian zones and freshwater inland wetlands both provide what valuable ecological service?
water for livestock filters out toxic wastes reduces flooding/erosion maintain biodiversity riparian zones- thin strips and patches of vegitation that surround streams; very important habitats and resources of wildlife freshwater- water has a dissolved salt content of less than one percent
Fire suppression which allows dead wood, leaves, and other flammable ground litter to accumulate can result in what happening?
when fires occur they will be more severe, and dying organisms overcrowd the ecosystem fire suppression- reduction of the heat released by a fire, and preventing regrowth
how to read age structure diagrams
wide at the bottom and skinny on top: rapid population growth, high infant mortality same shape throughout: stable population growth
how are humans affecting the water cycle?
withdrawing large amounts of freshwater polluting surface and groundwater clearing vegitation eroding soils
what organism is responsible for converting nitrogen gas into a usable form plants can absorb from the soil, and what is the process called?
bacteria nitrification- conversion of atmospheric nitrogen gas into forms from the environment to organisms and then back to the environment
why is replacement level fertility slightly higher than 2 children per couple?
because some children die before they reach reproduction age replacement level fertility- number of children a couple must have to replace them; the average for a country is slightly higher than two because some children die before reaching reproductive age
a species fundamental niche is __ than its realized niche
bigger fundamental niche: entire conditions an animal can survive under realized niche: conditions an animal actually uses to survive
which gas is used by plants for photosynthesis and released by all living things during cellular respiration?
carbon dioxide CO2
A farmer in a developing nation will try to put the maximum amount of crops on the land. This farmer would most likely use which method to remove the trees from his land?
clear cutting-method of timber harvesting in which all trees in a forested area are removed in a single cutting
assume that an ecosystem has an ecological efficiency of 10%. If a population of herbivorous caribou has an energy content of 20,000 Kcal. We would expect the energy content of its immediate predator, the grey wolf to be:
10% of 20,000 Kcal = 2000 Kcal
From the video "Dont Panic" what is the current birthrate in Bangledesh?
2.45 born per women 21.61/1000 ?
a town of 20,000 people has 600 births, 150 deaths, 200 emigrants, and 150 immigrants over a 1 year period. what is its population growth rate?
20,000 + 600 - 200 + 150= 20400 20400 - 20000/ 20000 = grew 2%
the net primary productivity of an ecosystem is 4kg C/m2/year, and the energy needed by the producers for their own respiration is 1.3 kg C/m2/year. The gross primary productivity of such an ecosystem would be __
3.7 because you have to subtract 4 by 1.3
Over the past ___ years, ___ evolution has generated all the biodiversity of the planet
3.7 billion biological
what international treaty bans the hunting, capturing, and selling of threatened or endangered species in over 160 countries?
Convention on International Trade in Endangered Species
legislation that makes it illegal to buy, hunt, kill or injure any threatened or endangered species in the US is the:
The Endangered Species Act of 1973
what would the area under the first curve depicted by the letter B would best be described as?
a lot of individuals using a small amount of resources = competition
four examples of secondary succession
abandoned farmland heavily polluted streams burned/cut off forests flooded land secondary succession- ecological succession in an area in which natural vegitation has been removed or destroyed but the soil is not destroyed
what are examples of non point source pollution?
air pollution run off non point source pollution- large or dispersed land areas that discharge pollutants into the environment over a large area
what groups of animals is declining the most in species diversity around the world?
amphibians bird fish
what are the most important factors in helping to stabilize a developing countries population, thus reducing environmental degradation?
availability of birth control infant mortality rate womens education urbanization pension systems children in the labor force
