Ch 24: Populations and Sustainability (in progress)

what happens in the slow growth stage of population growth?

small number of individuals and the birth rate is greater than the death rate

what happens in the rapid growth stage of population growth?

the number of breeding individuals increases and the overall population increases exponentially with no constraints to growth

what happens in the stable state of population growth?

further growth is limited, the population size fluctuates but remains stable, the birth rates are similar to the death rates

what are limiting factors when it comes to population?

abiotic: light, pH, water/oxygen availability, humidity
biotic: competition, food, predation, disease

What is carrying capacity?

The maximum population size that an environment can support

what is immigration?

Movement of individuals into an area, increasing the population size

what is emigration?

movement of individuals out of an area, decreasing the population size

what are density independent factors?

factors that effect the population regardless of its size and can cause a dramatic change

what are examples of density independent factors?

fires, earthquakes, volcanic eruptions, extreme weather

what is intERspecific competition?

competition between different species

what is intRAspecific competition?

competition between members of the same species

describe how interspecific competition happens

2 or more species compete for the same resource, leading to a decrease in that resource. some species may be better adapted to compete so the less well adapted get outcompeted

What is the competitive exclusion principle?

no two species can occupy the same niche in the same habitat at the same time effectively

what causes intraspecific competition?

the availability of resources causes competition and determines the population size, which results in fluctuations over time

describe how intraspecific competition happens

a resource is plentiful in a habitat so all organisms have enough and can survive and reproduce, increasing the population. more individuals need the resource so the resource decreases, decreasing the population.
with less population, there is less competition and so there is more resource and increase in population

What is predation?

biotic factor where predator eats prey, creating a form of interspecific competition

how did predators and prey evolve side by side?

predators evolved to catch prey efficiently while prey evolved to avoid capture

what word describes the relationship between predators and prey?

interlinked - as one changes, so does the other

how do predator-prey populations change over time?

prey population increases meaning there is more food for predators, so predator population increases. more prey get eaten so prey population decreases. not enough food for predators, they decrease, prey increase and so forth

what is conservation?

maintenance of biodiversity through human action or management

what is conservation good for?

maintaining species, genetic and habitat diversities

what is sustainable development?

managing ecosystems so the natural resources in them can be used without being fully depleted

what is reclamation?

Restoring ecosystems that have been damaged or destroyed

what is preservation?

The protection of an area by restricting or banning human interference, so that the ecosystem is kept in its original state.

what is preservation used for?

ecologically, archaeologically and palaeontologically sensitive resources

what is the economic importance of conservation?

provides resources and source of income

what is the social importance of conservation?

it maintains natural beauty for people to enjoy for exercise or relaxation

what is the ethical importance of conservation?

all organisms have the right to exist and play an important role in the ecosystem, we have a moral responsibility for future generations

what are sustainable resources?

renewable resource being used in such a way that it will not run out

what are the key aims of sustainability?

ensures availability of resources for the future, less economically developed countries can develop through use of resources, more comfortable living

what is sustainable timber production?

maintenance of forests biodiversity while also meeting the demands for wood supply and economic viability

what is coppicing?

Cutting tree trunks near the ground allows new shoots to form from the cut stumps and mature and grow. then the new branches are eventually coppiced too

what is rotational coppicing?

dividing forest into areas, coppice one area, wait then do next and wait, keep going until we come back to the first area, which will be grown enough to be coppiced again

What is pollarding?

same as coppicing but tress are cut higher up to prevent new shoots from being eaten

what are some large scale sustainable timber production methods?

selective cutting, when only the largest trees are felled.
replanting trees at optimum distances to reduce competition

what is sustainable fishing?

using fishing quotas that limits certain species of fish caught in an area, using larger mesh sizes to allow baby fish to escape

what is the ecosystem like in the Masai Mara National Reserve?

mainly savannah with the Mara River running through it. closer to the river are rich grasslands and woodlands, further away are open plains

what are some of the main, larger animals in Masai Mara?

elephants, buffalo, lions, leopards, black rhinos
wildebeest and zebra migrate annually

how does grazing happen in Masai Mara?

tribes used the land for livestock grazing in a semi-nomadic way but now the tribes cannot enter the reserve so the farms are on the edge.

what is cultivation on the farms of Masai Mara?

more grasslands are turned into croplands meaning there are less nutrients in the soil as natural vegetation is removed. this leads to an increased dependence on fertilisers

what is ecotourism?

tourism that is directed towards helping the natural environment, it supports conservation efforts

what are the key principles of ecotourism?

no exploitation of the environment and its local communities
engage with local communities about any development plans
improvements must benefit local people

what are the disadvantages of ecotourism?

it increases soil erosion with trampling in hiking trails and use of motorised transport

how are the black rhinos of Masai Mara being protected?

they are critically endangered.
poachers better deterred, park rangers introduced, better equipment

what are being researched in Masai Mara?

spotted hyenas, Mara River Basin flows, lion and cheetah populations

how do we maintain balance between humans and animals in Masai Mara?

fencing farmland to prevent elephants trampling crops, using legal hunting to maintain population sizes

what is the ecosystem like in the Terai region of Nepal?

hot, humid summers. fertile, alluvial soil for agriculture, lots of subtropical plants, floodplains and thick forests