6.3.2 Populations and Sustainability Flashcards
Draw, label and annotate with explanations, a generalised growth curve for natural populations
*diagram on flashcard
- lag phase - slow growth - small number of individuals
* low reproductive rate
* death rate low. birth rate > death rate
* nutrient level high - log (exponential) phase - rapid growth - number of
breeding individuals increases
* population size multiplies exponentially
* high reproductive rate
* death rate low birth rate»_space; death rate
* nutrient level high - stationary phase - stable state - population growth
prevented by external constraints
* birth rate = death rate
* nutrient level low - death phase - reproductive rate low
* death rate high
* nutrient level very low
Define abiotic factor
the non-living conditions in a habitat
Define biotic factor
the living components of an ecosystem
Define limiting factor
the factor which limits the rate of a process
Define carrying capacity
the maximum population size that an environment can support
What are (3) examples of (abiotic+biotic) limiting factors for population size and explain how they affect population size?
abiotic: temperature, pH, light intensity, water availability, oxygen concentration, humidity
biotic: predation, food supply, grazing, paratism, disease, intraspecific and interspecific competition
Define density dependant factors and give 3 examples
factors whos strength depends on the population size
e.g. competition, predation, grazing, disease
Define density independant factors and give 3 examples
factors that will affect the same percentage of the population regardless of its size
e.g. natural disasters, temperature
Define migration
the movement of individuals from one place to another
Define immigration
the movement of individuals into a particular area
increases population size
Define emigration
the movement of individuals out of a particular area
decreases population size
Define intraspecific competition
competition between organisms of the same species
Define interspecific competition
competition between organisms of different species
4 examples of what organisms might compete for?
*space
*food
*light
*water
Describe and Explain the competitive exclusion principle
Competitive exclusion principle -
where 2 species are competing for same limited resources
the one that uses resources more effectively will ultimately eliminate the other/ the two species cannot coexist
Why intraspecific competition an example of a density dependent biotic factor and why can it result in population fluctutations over time?
intraspecific competition occurs when members of the same species compete for the same resources.(biotic)
-greater availability of resource all organisms survive and reproduce
- reproduce = higher population size
- resources limited now as more sharing of food and space
-> population decreases
now less competition in smaller population = pop growth
Define predator
an animal that naturally preys on others
captures and feeds on other animals
Define predation
the capturing of prey in order to sustain life
Explain the general pattern shown in predator-prey relationships?
stage 1 -
*increase in prey population provides more food for predators - *more can survive and reproduce = increase in predator population
stage 2 -
*increase predator population eats more prey organisms = prey population declines
* death rate of prey»birth rate
stage 3 -
* reduced prey population can’t support large predator population
*intraspecific competition for food increases = decrease in predator population size
stage 4 -
* reduced predator numbers = less prey population killed
*more prey organisms survive and reproduce = increase prey population
CYCLE BEGINS AGAIN
Define conservation
the maintenance of biodiversity through human intervention or action
Define preservation
the maintenance of ecosystems in their original state - without interference and human use
What is the difference between preservation and conservation?
Conservation is an active process
Preservation is passive
Define reclamation
restoration of damaged ecosystems that have been degraded by human activity or impaired by natural disaster
What are 3 examples of conservation?
- Using grazing to keep Fen land from becoming woodland
- removal of invasive species like grey squirell
- legal hunting of animals in nature reserves to reduce population from potentially damaging levels
What are 3 examples of preservation?
- international agreement preventing large scale human activity in Antarctica - only scientists allowed on island of Surtsey
- Gating pristine caves to prevent people entering - to protect fragile ecosytems and geology
Define social when referring to reasons for conservation of biological resources
give 2 examples
reasons that are for the benefit of society, provide areas for relaxation, exercise and hobbies
Define ethical when referring to reasons for conservation of biological resources
reasons based on rights given to organisms/environment by some people or the moral responsibility we have
Define sustainability
the use of a natural resource without damaging biodiversity and ensuring that the resource is not depleted
Define sustainable resource
a renewable resource that can be exploited economically and it will not diminish or run out
Define sustainable resource
a renewable resource that can be exploited economically and it will not diminish or run out
What are the 5 aims of sustainability?
1) perserve the environment
2) ensure resources are available for future generations
3) allow humans in all societies to live comfortably
4) enable less comfortable countries (LEDCs) to develop, through exploiting their natural resources
5) create a more even balance in consumption of resources between LEDCs and MEDCs
What are 3 things that can be done to reduce the demand for a resource?
Reduce, Reuse, Recycle
- reduce consumption of resource
- reuse resource in og form
- rectcle resource after use and create new things
What are 2 methods of small scale timber production?
Coppicing
+
Pollarding
Describe process of Coppicing
(small scale)
-cutting tree trunk close to the ground
- to allow new shoots to grow from stumps and then harvest shoots at regular intervals
What is an advantage of pollarding over coppicing
new growth is higher up
-> protected from grazers e.g. deer
trunk also provides habitat absent from coppiced trees
Describe process of Pollarding
-cutting tree trunk back to a few metres above ground level
- allow new shoots to grow up from the top of the trunk
- harvest the shoots at regular intervals
Explain rotational copping and advantage of it
- divide woodland into sections - trees coppiced in 1 section every year
- rotational copping allows time for growth between cutting - + maintains habitats for other organisms
What is the difference between harvesting in large scale timber production and harvesting in small scale timber production?
in large scale timber production trees are felled and do not regrow - they are replanted
in small scale trees are regenerated
What do timber companies do to ensure that large scale timber is sustainable? (5)
1) Practice selective cutting (remove largest trees)
2) replace trees through replanting not wait for natural regeneration
3) plant trees an optimal distance apart - reduce competition = maximise yield
4) manage pests and pathogens - maximise quality + size of yield
5) ensure areas of forest remain for indigenous people
What are disadvantages of large scale timber production?
- Habitats destroyed
- Soil minerals reduced
- Bare soil left - vulnerable to erosion
What is the international agreement that aims to ensure that fishing is sustainable in the EU? Describe it
Common Fisheries Policy in the EU
- set fishing quotas and regulations
What are 3 methods that help fishing be mores sustainable?
- Larger mesh in nets/ different mesh sizes
- allow younger fish to escape - can breed
- only mature fish caught - Restrictions on time of year for fishing
- protect breeding season of some species
- allow individuals to increase - Fish Farms
- reduces pressure on wild population and
maintain protein supply for diets
Why would overfishing in 1 particular area not likely to make a species extinct?
It will only reduce or eliminate the population in the specific area - locally extinct
- species will survive elsewhere in the world
- so not extinct
What does MMNR stand for and where is it?
Masai Mara National Reserve
South Kenya
What is the ecosystem like in the Masai Mara?
- Savvanah
- fertile rich grassland + woodland around river
What animals are found in the Masai Mara?
zebra, buffalo, elephants, rhino, leopards, lions
What impacts have local humans had on the Masai Mara ecosystem?
-used to practice semi-nomadic farming (livestock grazing)
- grazing now limited to
edges of reserve
-more cultivation of crops+trees for fuel and cultivated grazing
-removal of soil nutrients - reliance on fertilisers as grassland now cropland
- soil erosion risks
Define ecotourism
tourism directed towards natural environments to support conservation efforts and observe wildlife
What are the 3 principles of ecotourism?
1 - ensure tourism doesnt exploit the natural environment/natural communities
2 - consult and engage with local communities on new developments
3- ensure that infrastructure improvements benefit local people and visitors
What are negative impacts of tourism?
-repeated use of hiking trails
-mechanised transport
soil erosion and habitat changes
Describe the change in the population size of the black rhino since the early 1970s?
1972 - 100+ black rhinos
1982 - only a handful
numbers now increasing but not recovered to levels in 1970s
What are the threats to the black rhino? and what conservation techniques have been put in place?
Rhino horn used in traditional medicine in South east Asia
employed rangers with comms, vehicles and other infrastructre+equipment has acted as a deterrent to poachers
What are 4 scientific research projects in the Masai Mara?
*Michigan State University - behaviour and physiology of the spotted hyena
*Subalusky and Dutton - flow assessment of Mara River basin
*The Mara Predator Project - catalogues and monitors lion populations to identify responses to change
*The Mara Meru cheetah project - monitor cheetah population and evaluate human impact
What are 4 examples of conflict between human needs and conservation in Masai Mara? give ways to balance this conflict
- elephants trample crops + damage homesteads
- land can be fenced but distrupts natural migration patterns
*legal hunting to cull excess animals and maintain the levels of some populations - numbers constantly monitored to maintain balance
*Wilderbeast outcompete cattle for grass and cattle eat vegetation zebras would, diseases from wilderbeast to domesticated animal population - increasing human population needs more homes and land for cattle+agriculture
decreases wildlife density
Describe the location of Terai region of Nepal
-southern part of nepal along border with India
What is the ecosystem like in the Terai Region of Nepal
- hot and humid in summer
- fertile soil
- well watered flood plains
- tropical and subtropical forest
-extreme biodiversity
What are some of the animals found in Terai region of Nepal?
bengal tiger
sloth bear
indian rhino
What is the impact of human populations on the Terai regions ecosystem?
- large areas of forest cleared for agriculture for timber
increase effects of
monsoon flooding
leaves small pockets of forest
How is sustainable forest management helping to balance the conflict between human needs and conservation of Terai region
- Aim to provide livelihood for people
- provide state with income for general development while conserving the forests
- local community forest groups set harvesting rules, rates, prices for products and decide how surplus income is spent while government provides supporting national legislation
What are 6 positive outcomes for community forestry groups in the Terai Region?
- improvement in area and density of forest regions
- improved soil and water management
- increase in retail price of forestry products = greather economic input
- forest protection = employment + income
- sustainable wood fuel sources = local household needs
- secure biodiversity of forested areas
What are management strategies for sustainable agriculture to protect the Terai region?
-growing fruit + vegetable crops in mountain regions - reduce pressure on Terai region
-improve irrigation + improved fertiliser = better crop yield
-multiple cropping - more than 1 crop grown on each piece of land each season
- nitrogen fixing crops grown - pulses + legumes = enchance soil fertility
-* grow crop varieties resistant to various soil,climatic + biotic factors through biotechnology+genetic engineer
What are 2 locations of peat bogs in UK?
Somerset levels
Greater Manchester
What is the ecoystem of peat bogs?
wet spongy containing decomposing vegegation
What impact has the local human populations had on the ecosytem of peat bogs?
Peat extraction
draining for agriculture - increase soil
acidicity + structure
planting trees
= all dry out bogs
What are 3 conservation organisations helping to balance conflict between human needs and conservation of peat bogs in the UK?
The Wildlife Trusts
Natural England
Royal Society for the Protection of Birds
(RSPB)
What are 3 conservation organisations helping to balance conflict between human needs and conservation of peat bogs in the UK?
The Wildlife Trusts
Natural England
Royal Society for the Protection of Birds
(RSPB)
What are 3 conservation methods to maintain/restore lowland peat bogs?
- Ditch blocking - prevents drying out and raises water table to bog surface
=peat undisturbed + wet - Removing tree seedlings - prevents reduced water bc trees have high ater requirement
= maintain water levels - Controlled grazing - ensure diverse wetland surface (structure+species)
= wide range of habitats for rare insects
Define environmentally sensitive ecosystem
ecosystems with - low resistance to change
What are the 4 environmentally sensitive ecosytems you need to know?
Galapagos Islands
Antarctica
Snowdonia national park
The lake district
What are 5 management techniques used in environmentally sensitive ecosytems?
- limit areas tourists can visit
- control livestock movement
- introduce anti-poaching measures
- replanting forest and native plants
- quotas + seasonal plans to limit hunting
Where are the galapagos islands located? what is the nature?
Pacific ocean, west of Ecuador
- volcanic islands
What 3 animals are present in the galapagos islands?
Giant tortoise
Marine Iguana
Flightless Cormorant
What are the 3 plant zones in Galápagos Islands? what plants are found in them?
Coastal Zone - saltbush, mangrove
Arid zone - cactus, carob tree
Humid Zone - dense cloud forest - mosses, liverworts
Define flora and fauna
flora - plants of a particular habitat
fauna - animals of a particular habitat
What 5 measures have been taken place to protect the Galapagos island ecosystem?
- park rangers
- limit human access to specific parts
- control migration to/from islands
- strict controls on introduced animals
What is the nature of antarctica?
- 2km thick ice sheet
- contains 70% of worlds fresh water
- coldest + emptiest continent
- 2 seasons
What 3 animals are present in Antarctica?
- Emperor pengiun
- Weddell seal
- Humpback whales
What plants grow in Antarctica? what is their nature?
algae, lichens and moss
-plants only grow in non ice regions
What are 4 impacts of human activity on Antarctica?
- global warming causes ice sheets to melt and break
- hunting whales and seals and fishing has depleted stocks
- soil contamination around research sites
- releasing waste into sea
What are 5 provisions of the ‘Antarctica Treaty’ that help protect its ecosystem?
- scientific coorperation between nations
- protecting the antarctica environment
- conservation of plants + animals
- designation and management of protected areas
- managing tourism
Where is Snowdonia National park located?
North west wales
What is the nature of Snowdonia like?
Highest mountain range in England and Wales
- lakes + fast flowing rivers
- ancient woodland + heath
What are 3 habitats for birds and which birds live in each, in Snowdonia?
- Coast and estuary - cormorants + oystercatchers
- Moorlanf and mountain - ospreys, buzzards + sparrow hawks
*Forest - redstart, wood warbler
What is 1 plant that is adapted to the extreme conditions on Mount Snowdon?
Snowdon Lily
What are 3 purposes of the Snowdonia national park in order to conserve biodiversity?
1- Conserve + enchance the natural beauty, wildlife + heritage of area
2- Promote opportunities for the understanding + enjoyment of the park
3- Enhance economic + social well being of communities within the park
Where is the Lake district and nature of it?
- North West England
ancient woodland, moorland + fell
How does the Dinworg power station manage conflict between human need + conservation of biodiversity?
Is a hydroelectric power station built
1- to meet needs of national grid
2- located within mountain = less habitat disruption + preserve natural beauty
What are some animals found in The Lake District?
Red squirrel
Golden eagle
Vendace
Water voles
Define Arctic-alpine plant community
Plants found above the treeline in arctic +/ mountainous regions
What are some arctic-alpine plants found in The Lake District?
Dwarf juniper
Dwarf willow
Purple saxifrage
What are some plants found in lowland regions of The Lake District?
Sundew
Carnivorous plant
What are 4 purposes of the Lake district park authority in order to conserve biodiversity?
conserving region while:
- enabling access to visitors to enjoy
- educate on nature
- active management of countryside
