6.3.2 Populations and sustainability
What is sustainable food production? How can you used this process in Fishing
Having enough food without using resources FASTER THAN THEY RENEW - by USING FISHING QUOTAS -Controlling the Mesh Size of Nets
What is RECLAMATION
a method of conservation which involves RESTORING ECOSYSTEMS that have been DAMAGED or DESTROYED so they can be used again e.g. : restoring forests that have been CUT DOWN so they can be used again
Leaving a section of woodland to mature for 50-100 years before felling allows biodiversity to increase. How to does modern sustainable forestry avoid this un-costeffective timescale
- Any tree which is harvested is REPLACED by another tree, either grown naturally or planted -The forest as a whole must maintain its ecological function regarding biodiversity, climate and mineral water cycles -local people should benefit from the forest
What are the ECONOMICAL REASONS for conservation?
- If ecosystems aren't conserved, the resources we use will be lost (because genetic diversity in wild strains is needed to breed for improved YIELD in plants) thus LESS TRADE in the future. Ecosystems provide resources for lots of things that humans need e.g. rain forests contain species that provide things like DRUGS, clothes and food These resources are ECONOMICALLY IMPORTANT because they're traded on a LOCAL and GLOBAL scale -many species have INDIRECT economic value e.g. insect species are responsible for POLLINATING CROP PLANTS. without insects a harvest may FAIL and farmers would go WITHOUT BUSINESS. likewise other communities are important in maintaining water quantity, protecting soil, breaking down waste products -ECOTOURISM depends on the maintenance of biodiverisiy and this brings in MONEY to a country -genetic diversity in wild strains may be needed in future to breed for diseases resistance and improved yields in animals and plants, and drought tolerance in plants. Likewise new plant species may be domesticated for food use
For what purpose is Coppicing used and HOW is it done.
- It's used to provides a sustainable supply of wood. It cuts trees in a way that allows them to grow back How is it done? -The stem of a deciduous tree (one that loses leaves in winter) is CUT close to the ground. -Once cut, new shoots grow from the cut surface and mature into narrow stems. -These stems can be used fore fencing, firewood or furniture -After cutting these stems off, new shoots start to grow again and CYCLE CONTINUES
What are the the two thing limiting factors are dependent on?
- Some limiting factors are DENSITY DEPENDENT- the factor influences the population MORE STRONGLY as population size increases e.g. the AVAILABILITY OF RESOURCES like food, water, light, oxygen may decrease, Also as population size increases, predation from other species may increase, as well as an increase in the intensity of COMPETITION for resources -Some limiting factors are not DENSITY DEPENDENT - these are limiting factors that act strongly, irrespective of the size of the population e.g. low temps very low temps may kill the same proportion of individuals in a population irrespective of their size
How are Mesh Size of Nets controlled? What are problems associated with it?
- There are different limits to the mesh size of fish net, depending on what's being Fished - This is to reduce the number of UNWANTED and DISCARDED fish that are accidentally caught. Using BIGGER mesh size will let the 'unwanted' species escape (e.g shrimp caught along with cod) -It also means younger fish will slip through the net, allowing them to REACH BREEDING AGE PROBLEMS: -It is difficult to determine exactly how big the mesh size should be in areas where SEVERAL DIFFERENT FISH SPECIES are fished for at the same time -two nets, each of which meets regulations could be used ONE INSIDE THE OTHER- reducing the reported mesh size
What are r-strategists and give examples of some
- species whose population size increases SO QUICKLY that it exceeds the carrying capacity of a habitat before the limiting factors start to have an effect -once carrying capacity of has been exceeded, there are no longer ENOUGH RESOURCES to allow individuals to reproduce or even survive -also an excess build up of waste produces will be lethal, thus species begin to die, -e.g. mice, insects, spiders, weeds
What is the effect of predator-prey relationships on predator and prey populations
-As PREY population INCREASES-->more food for predators-->Thus PREDATOR POP GROWS - As PREDATOR pop INCREASES-->more prey is eaten--> PREY POP FALLS. This is an example of NEGATIVE FEEDBACK - the prey population is RESTORED (to a more STABLE SIZE after an unstable increase) - decrease in prey pop-->less food fro predators-->predator pop decreases (more negative feedback, pred pop decreases after an increase), and so on -with fewer predators-->fewer prey are eaten--> their population size increases -with more prey-->predator population increases and CYCLE STARTS AGAIN negative feedback= counteraction of an effect (e.g when prey pop increases, the effect is counteracted by a decrease in the prey pop)
What is Interspecific competition AND what does it affect
-Competition BETWEEN different species for the the same resources -Intraspecific competition affects both population size and DISTRIBUTION OF SPECIES IN AN ECOSYSTEM
What is intraspecific competition and what does it affect
-Competition WITHIN species (competition between individuals of the same species) - affects population size
What are the SOCIAL reasons for conservation of biological resources ?
-Ecotourism- many ecosystems bring JOY to lots f people because of the aesthetic value of living things -People use ecosystems for ACTIVITIES e.g. birdwatching and walking. The species and habitats in the ecosystems may be LOST if they aren't conserved-->thus further generation won't be able to use and enjoy them -Natural environments are a valuable of BENEFICIAL ORGANISMS--> many of the drugs we use today were discovered in WILD PLANT SPECIES
How does INTERSPECIFIC competition affect DISTRIBUTION OF SPECIES
-If two species are competing but one is BETTER ADAPTED to its surrounding/to obtaining resources than the other --> the less well adapted species will be OUT-COMPETED --> Thus it wont be able to EXIST / alongside the better adapted species (the population will eventually die out) -THIS EXPLAINS WHY PARTICULAR SPECIES ONLY GROW IN PARTICULAR PLACES -e.g. since the introduction of the grey squirrel to UK, the native red squirrel has disappeared from LARGE AREAS . the grey squirrel is better adapted since its larger and can store MORE FAT over winter, thus it has a BETTER CHANCE OF SURVIVAL -However EXTINCTION of one species is not always inevitable- intraspecific competition can sometimes simply result in one population BEING MUCH SMALLER than the other , with each population size remaining quite constant
Why must overfishing be avoided?
-It can reduce fish populations to zero--> causes species to become extinct
What are k-strategists and give examples of some of them
-Species whose population size is determined by carrying capacity / density dependent limiting factors - For these populations, limiting factors factors have a STRONGER EFFECT as population size increases and gets CLOSER TO CARRYING CAPACITY--> this causes the population size to gradually LEVEL OUT -e.g birds, lager mammals (Humans and elephants), larger plants
How does the management of a woodland provide resources (timber) in a sustainable way
-Temperate woodland can be managed in a sustainable way- for every tree that's cut down for timber, a NEW ONE is planted in its place - The woodland should never become depleted 1. Trees are cleared in STRIPS OR PATCHES- woodland grows back MORE QUICKLY in smaller areas between bits of EXISTING woodland that it does in larger more open areas than it does in larger, OPEN AREAS 2. The cleared strips or patches aren't too large or exposed- lot's of soil erosion can occur in large areas of BARE GROUND If the soil is eroded, newly planted trees WON'T BE ABLE TO GROW 3. Timber is sometimes harvested by COPPICING-cutting down trees in a way that LETS THEM GROW BACK. This means new trees don't need to be planted 4. NATIVE tree species tend to be planted in preference to non-native species . This is better for BIODIVERSITY because native species have long-established INTERACTIONS with other native species (E.G. plants, fungi, animals) so their presence (native) should help species THRIVE in an area. Also some species might not adapt to the presence of non-native tree species 5. Planted trees are attached to POSTS to provide SUPPORT and are grown in PLASTIC TUBES to stop them being eaten by grazing animals --> makes it more likely trees will survive to become more adults 6. Trees aren't planted TOO CLOSE together- this means the trees aren't COMPETING with each other for SPACE or RESOURCES thus they more likely to survive
Sustainably managing forests involves BALANCING CONSERVATION against the need to harvest wood in order to maintain biodiversity . If each tree supplies MORE wood, FEWER trees need to be harvested. What do foresters do to achieve trees that supply more wood?
-control pests and pathogens -only plant particular tree species where they know they will grow well - position trees an optimal distance apart. If trees are too close this causes too much competition for light, and they grow tall and thin- producing poor-quality timber
How is fishing used to provide resources in a SUSTAINABLE WAY
-fish stocks are declining because we're overfishing-this means there's less fish for us to eat, the oceans food chains are affected and some species of fish may DISAPPEAR altogether in some areas -to tackles this problem we need to maintain fish stocks at a level where the fish CONTINUE TO BREED --> this is SUSTAINABLE food production
(b) What biotic factors influence population size
-intraspecific competition -interspecific competition -predation
How can management of ecosystems provide resources in a SUSTAINABLE way
-managing timber production -managing fish stocks -enough resources are taken to MEET THE NEEDS OF PEOPLE TODAY, but without reducing the ability of people in the future to meet their own needs
What are the ETHICAL reasons for conservation
-some think we should conserve ecosystems simply because it's the RIGHT THING TO DO e.g. some think organisms have a RIGHT TO EXIST ( species have value) , thus they shouldn't become extinct as a result of HUMAN ACTIVITY -some think we should conserve because we have a MORAL RESPONSIBILITY to do so for FUTURE GENERATIONS , so they can enjoy and use them
How does intraspecific population affect population size?
-the population of a species increases when resources are plentiful. As population increases, there will be MORE organisms competing for the same AMOUNT OF SPACE AND FOOD -individuals BEST ADAPTED to obtaining food survive and reproduce, whilst individuals not well adapted DIE --> this slows down population growth and population enters STATIONARY PHASE( carrying capacity reached) -A smaller population means theres LESS LIKELY to be competition for space and food, which is BETTER for growth and reproduction - thus population starts to GROW again -If pop size INCREASES, competition INCREASE thus population size drops -intraspecific competition keeps population size quite stable despite slight fluctuations during stationary phase
How can can the ecosystem of UK Peat Bogs be managed to balance the conflict between conservation/preservation and human needs
1. Lots if upland parts of UK are home to peat bogs- areas of wet peat. 2. Peat bogs store water and CO2, and habitat for many diff PLANTS AND ANIMALS 3. Farmers use pet bogs to GRAZE SHEEP and deer--> leads to CONFLICT with conservationists because: -OVERGRAZING causes loss of moss species (which help peat bog by retaining water) - soil compaction - increases water runoff (flow of water that occurs when excess water flows over the Earth's surface) down sheep paths and destroys habitats - peat bog erosion ANSWER -recent GOV FUNDED PROGRAMMES like the Environmental Stewardship Scheme, have given farmers money to use peat bogs in a SUSTAINABLE WAY through: -lowering no. of livestock that uses peat bogs -remove livestock over winter -reduce water runoff
What is the affect of Human activities on animal and plant populations in Galapagos Islands ( An environmentally sensitive ecosystem) and how are these controlled
BACKGROUND -The galapagos islands are a small group of islands in the Pacific Ocean. Many rare species of animals and plants have evolved there that cannot be found elsewhere. They attract a number of tourists. EFFECTS OF HUMAN ACTIVITIES: 1.Population size has increased placing huge demands on water, energy and sanitation services-->thus MORE POLLUTION and waste produced. 2.Demand for oil has increased- and oil spill in 2001 had a dramatic effect on MARINE AND COSTAL ECOSYSTEMS 3.BUILDING AND CONVERSION OF LAND FOR AGRICULTURE- caused destruction and fragmentation of habitats - many shrees and shrubs that are unique to the islands have thus been eradicated 4. NON-native animals that are introduced to the islands by humans EAT some native species/ destroy native spcies' habitats/ bring diseases into island --> causes populations of native species to decrease--> e.g. non-native dogs, cats and black rate , goats eat young giant tortoises and galapagos island iguanas 5. Non-native plants have been introduced to the islands--> these COMPETE with native plant species causing a DECREASE in their populations. for example, QUININE TREES are taller than some native plants-they BLOCK OUT LIGHT to native plants, which the struggle to survive 6. OVER-EXPLOITATION OF RESOURCES: Whaling boats and fur traders killed 200000 tortoises in in less than half a century 7. FISHING OF EXOTIC SPECIES- depletes populations and endangered species METHOD OF CONTROL: 1. Eradication programmes have REMOVED WILD GOATS from some of the smaller islands and wild dogs from the largest island. quinine trees are kept in check using CHEMICAL HERBICIDES and by UPROOTING young trees 2. CAPTIVE BREEDING PROGRAMME set up by Charles Darwin Research Station to supplement tortoise numbers 3. Charles Darwin Research Station SEARCH ARRIVING BOATS and tourists or foreign species 4. CULLING (killing) has been used against FERAL GOATS and PIGS on islands 5. Educating new residents about conservation 6. 'NO-TAKE' areas designated to coastal zones, where NO EXTRACTION OF RESOURCES IS ALLOWED -->communities left undisturbed 7. Natural predators have been released to wipe out pest populations- thus reduces the damage caused to ecosystems by pest populations
((e) the management of environmental resources and the effects of human activities.)t How can can the ecoystem of the TERAI REGION be managed to balance the conflict between conservation/preservation and human needs
BACKROUND -The Terai arc is an area of forest and grasslands on the border between Nepal and India - A VARIETY of plants and animals are found here, including the ENDANGERED SPECIES like BENGAL TIGER and ASIAN ELEPHANT -The area is also highly populated, and the population is highly DEPENDENT on the forest's resources to survive e.g areas of forest are being destroyed to make way for HOUSING and OTHER DEVELOPMENT -this destruction of habitats brings humans and animals into closer contact and there is thus CONFLICT between animals and human/human needs e.g elephants can EAT and trample crop fields and tigers can KILL LIVESTOCK --> this thus reduces conservation since it increases the likelihood of animals being shot and killed ( there is thus conflict between human needs and conservation of animals/plants) ANSWER: -Conservation charities like the WWF has have helped to manage this conflict between conservation and preservation. WWF have worked with local people to help BALANCE their needs with conserving the forests -For example the charity has provided people with things like SOLAR COOKERS and BIOGAS GENERATORS to reduce demand for firewood/ thus they don't need to used wood from the forest as fuel --> THUS CONSERVING THE ECOSYSTEM -Waterholes were constructed, endangered species are monitered, and eradicating invasive species
GO OVER THIS BIT W TEXTBOOK (e) the management of environmental resources and the effects of human activities. How can can the ecosystem of the Massai Mara be managed to balance the conflict between conservation/preservation and human needs
BACKROUND 1. The Masai Mara is a national reserve in Kenya. It is a large area of grassland (savannah) which is home to huge population of WILDEBEEST and ZEBRA, LIONS and CHEETAHS -The Maasai people traditionally earn a living by raising LIVESTOCK such as cattle (that graze). However, This can bring them into conflict with conservationists - OVERGRAZING by livestock can destroy grassland for WILDLIFE (thus there is a conflict between human needs and conservation here) ANSWER: Conservation trusts are working with Maasai people to: - help them make money from their land through CONSERVATION and ECOTOURISM PROJECTS rather than farming (which reduces area for wildlife) Conservancies have positive social outcome (make money) as well as positive conservation outcomes -Farm in a SUSTAINABLE WAY - THUS the economic needs of the maasai people are met, while still allowing the area to be conserved ( the conflicts of human needs and conservation are thus balances) HOWEVER not needs not balanced because with some conservancies, land-owners must move their LIVESTOCK out during tourist season -->leads to increased stocking density outside reserve where they receive no money from. livestock grazing is very important in Maasai culture Also land-owners of conservancies are constrained on how they use their land, and they forced to settle elsewhere HUMAN NEEDS= grazing/farming to make MONEY CONSERVATION
How is timber produced on a small scale?
Coppicing
How does INTERSPECIFIC competition affect population size
EFFECT ON POP SIZE: interspecific competition between two species means that the resources available to BOTH populations are reduced e.g. if they share the same food source, there will be less available for BOTH of them--> thus both populations limited by lower amount of resources--> thus they both have LESS ENERGY FOR GROWTH and REPRODUCTION--> thus population size DECREASES FOR BOTH SPECIES -both species' population sizes remain relatively constant
What is the affect of Human activities on animal and plant populations in Lake District( An environmentally sensitive ecosystem) and how are these controlled
EFFECTS OF HUMAN ACTIVITIES 1. Many visitors to lake district go walking on the regions footpaths-->leads to erosion of footpaths and loss of soil from hillsides --->soil that ends up in waterways and lakes can DISTURB pH of water-->causes effects for wildlife (that drink water) As paths become harder to walk on, people start to walk on side of paths which tramples and DESTROYS SENSITIVE VEGETATION as they try to walk around the floods 2. Hay meadows support a rich diversity of flowers and grasses. They are under threat due to SILAGE PRODUCTION which involves use of arifical fertiliser on hay meadows--> causes LOSS OF SPECIES DIVERSITY on grassland and pastures CONTROL= Farmers are paid to maintain hay meadows 3. Spruce and pine in conifer plantations support limited biodiversitY CONTROL=recent initiatives have generated more varied planting and felling patterns 4. Invasive plant species have escaped from gardens and spread into woodland OUTCOMPETE NATIVE SPECIES--> they reduce light reaching the woodland floor and their roots produce toxic chemicals which stop other plants growing CONTROL= they are physically removed by conservation workers 5. Cliff and rock communities support a rich diversity of plant life- provides habitat for birds (stonechat and wheatear) and nesting sites-->these communities are DAMAGED BY CLIMBERS AND WALKERS CONTROL= seasonal restrictions on walking when birds are nesting, walkers are educated to be more aware, paths well maintained to walk off the path INCLUDED HEATHLAND (pg 302) METHODS OF CONTROL 1. CONSERVATION CHARITIES: e.g. Lake District National Park Authority attempt to carry out regular repair and maintenance work on paths, and ENCOURAGE REGROWTH of damaged vegetation 2. WALKERS EDUCATED: educated by conservation charities about the importance of sticking to the paths and not taking short cuts, which increase erosion
What is the affect of Human activities on animal and plant populations in SNOWDONIA ( An environmentally sensitive ecosystem) and how are these controlled
EFFECTS OF HUMAN ACTIVITIES: 1. DESTROYING VEGETATION: Lots of rain falls in snowdonia hills, leads to erosion on paths-->thus walkers try to walk around flood--> often damage/trample the surrounding vegetation as they do so 2. Farmers dig open drainage ditches to dry the land -->water from ditches flow to rivers causes poor water quality in rivers, and rain flows quickly through the habitat--> INCREASING FLOOD RISK CONTROL= drainage ditches blocked by hay bales 3. Conifers planted as CASH CROPS (FOR MONEY)-->this dries out the moorland as trees absorb water--> thus affect habitat and it's populations Also Roads have to be build to carry wood from confers away---> compacts the land CONTROL=when trees are cut, branches are used to block drainage ditches in the area-->slows water flow--> hence keeps land (moorland) moist 4. MOORLAND BURNT to provide varied habitat for grouse. Some plants (old heathers) burn easily--> thus accidental fires= high risk e.g if peat (similar to soil sets on fire it DAMAGES HABITAT ON LARGE SCALES CONTROL= burning before heather gets too old and dry is important to prevent damage of habitats by fire 5. WALKERS DROP RUBBISH on paths which blocks gutters that take water from paths CONTROL- Workers clear rubbish METHODS OF CONTROL 1. DRAINS DUG- Volunteers have dug drains next to paths to prevent flooding 2. National park employees work with farmers to REDUCE SHEEP GRAZING on mountain- this gives plants better chance of survival
What is the affect of Human activities on animal and plant populations in Antarctica( An environmentally sensitive ecosystem) and how are these controlled
Effects of Human activities: 1. POLLUTION: Visitors to Antarctica have caused pollution in the past by dumping sewage into the sea and leaving rubbish. Shipping accidents have lead to OIL SPILSS which severely affects wildlife 2. REDUCED POPULATIONS: Hunting, whaling and fishing have all reduced wildlife populations in the area 3. LONG-LINE FISHING: this is when fisherman train a long fishing line behind their boat and attached are baited hooks -birds try to eat bait and swallow hooks thus DIE-- reduced sea bird populations METHODS OF CONTROL: 1. All waste apart from food waste and swages must be TAKEN AWAY by ship for disposal in other countries. Many research stations now treat their sewage before releasing it, to REDUCE it's effect on environment 2. Ships that use THICK OILS as fuel are now banned from Antarctic waters. heavy oil spills are likely to cause more damage and be harder to clean up the spills of lighter fuels. 3. TOURISM RESTRICTIONS: tourists are only allowed on land at CERTAIN LOCATIONS for a few hours 4. CERTAIN HUMAN ACTIVITIES BANNED: hunting and whaling have been banned 5. Krill are food for whales, seals, penguins other marine life- recent technology changes means large amounts of krill can be HARVESTED very quickly 6. Fishing boats congregate in areas with HIGH KRILL NUMBERS- thus to avoid over exploitation of krill, there is a TRIGGER LEVEL CATCH SIZE, which when reached fishing must be conducted equally across all areas up to the total catch limit to avoid catastrophic impact on predator populations 7. Lots of marine protected areas established- areas where it is illegal to hunt and kill certain animals e.g Southern Ocean Whale Sanctuary
What are some threats to biodiversity?
Increasing human populations threatens biodiversity: -over-exploitation of wild populations for food (e.g cod in the North Sea), for sport and commerce -habitat disruption and fragmentation cause by MORE INTENSIVE agricultural practices, increased pollution, or widespread building -species introduced to an ecosystem by humans that out-compete other native species, leading to their extinction
What type of factors affect population size and give examples of these
Limiting factors which include: Abiotic factors- e.g the amount of light, water or space available. Temp of their surroundings Biotic Factors- living features of an ecosystem When abiotic conditions aren't ideal for any species, organisms CAN'T GORW AS FAST or reproduce as successfully, thus restricting size of carrying capacity E.g. when the temperature of a mammals' surroundings is SIGNIFICANTLY lower or higher than their OPTIMUM temp-->they will have to use a lot of energy to maintain the right body temperature --> THUS less energy available for growth and reproduction--> THUS pop size will decrease
What is Preservation
Maintenance of habitats and ecosystems in their PRESENT conditions, minimising human impact -preservations eliminates any human effects on ecosystems -nothing is removes from a preserved ecosystem, and they're only used for activities that DON'T damage them. e.g. Antarctica is a preserved ecosystem because its protected from EXPLOITATION by humans (its only used for limited tourism and scientific research, not any industrial activities)
What is Conservation and what does it involve
The Maintenance of biodiversity including diversity between species, genetic diversity within species, and maintenance of a variety of habitats and ecosystems -conservation involves the MANAGEMENT of ecosystems: controlling how resources are used and replaced -conservation involves RECLAMATION- restoring ecosystems that have been damaged or destroyed so they can be used again or conservation is the PROTECTION and MANAGEMENT of ecosystems so that the NATURAL RESOURCES in them can be USED without them running out 8
What is a carrying capacity
The maximum population size that can be maintained over a period in a particular habitat. The habitat cannot support a larger population because factors LIMIT the growth in population size- these factors are called LIMITING FACTORS (limiting factors determine the carrying capacity of an ecosystem)
What is the definition of population size
The total number of organisms in ONE SPECIES in a habitat
What are 'Standards' in timber production
Trees in the process of rotational coppicing that have been coppiced but then have been left to grow LARGER without being coppiced. These trees are harvested eventually to supply larger pieces of TIMBER
What areF ISHING QUOTAS and how are they used? What are the problems associated with fishing quotas
WHAT? Fishing quotas are LIMITS to the amount of certain fish species that fisherman are allowed to catch They help Conserve fish species by reducing the number that are caught and killed THUS species aren't at risk from becoming extinct HOW? 1. Scientists study different species and decide HOW BIG their populations need to be for them to MAINTAIN THEIR NUMBERS at the CARRYING CAPACITY of their environment They then decide a limit to a amount of certain fish type fishermen can take WITHOUT REDUCING POP too much (the scientist decide on a fishing quota for a certain fish type, which wont affect pop size to much/ prevent them becoming extinct) 2. International agreements are made that state the AMOUNT of fish EACH COUNTRY can take, and where they're allowed to take it from . A FISHERY MUST COMPLY WITH LOCAL , NATIONAL AND INTERANATIONAL AGREEMENTS PROBLEMS? - Fish of the wrong species or size are still caught, but they end up being THROWN BACK into the sea, often dead or dying--> because restrictions don't allow the fishermen to BRING that species ASHORE
Why is rotational coppicing used? How is it done to produce TIMBER . Why is it good for biodiversity?
WHY -To provide a CONSISTENT supply of wood HOW -divide a woodland into sectors and CUT ONE SECTION each year -by the time they want to coppice the first section again, the new stems have matured and are ready to be cut -in some sections some trees are left to grow LARGER without being coppiced--> these trees are called STANDARDS and are eventually harvested to SUPPLY LARGE PIECES OF TIMER Why good for biodiversity? - In rotational coppicing, different areas of woodland provide DIFFERENT TYPES OF HABITAT--> letting more light in-->thus increasing the number and DIVERSITY of species whereas if woodland was left unmanaged-->woodland goes through process of SUCCESSION--> blocking out light to woodland floor--> thus reducing number of species growing theere
Explain the effect of a surrounding temperature that is much lower than a mammal's optimum temp, on the size of population
When the temperature of a mammals' surroundings is SIGNIFICANTLY lower or higher than their OPTIMUM temp-->they will have to use a lot of energy to maintain the right body temperature --> THUS less energy available for growth and reproduction--> THUS pop size will decrease
What is predation
Where an organism (the predator) kill and eats another organism (the prey)
how is conservation a dynamic process?
conservation methods need to be adapted to CONSTANT CHANGES (caused naturally and by humans) that occur within ecosystems