life processes in the biosphere (the living environment)

Succession

The process in which soecies colonise an uninhibited area, the stages in this process are called seres and are given different names depending on location

Hydrosere

If succession is happening in a water body,

Lithosere

If succession is happening on a rock

Psammosere

If succession is happening on sand

Pioneer species

The first living organisms to colonise an area such as lichens/mosses that have low requirements because the environment has no other life forms and little nutrients, they alter the abiotic conditions slightly eg thin layer of soil to make the area slightly less hostile

Climatic climax community

A final community of the dominant species left after species colonising, thriving and dying out leaves one species dominant which shouldn’t change if the climate remains the same

As succession continues…

Conditions become less hostile and volatile,

Abiotic Egs: temp extremes become more stable, water availability goes from variable to stable, light levels go from high to low as plants provide shade, nutrient availability from low to high and same for rates of change

Biotic: pollination goes from wind to insects, seed dispersal goes from wind to animals, inter species relationships and biomass and biodiversity go from low to high

secondary succession

Process happens in areas where soil is already present allowing a more sped up process and usually occurs in an area where there has been a fire or natural disaster removing vegetation and if climate hasn’t changed then shoukd reach same climax community

Plagioclimax community

Where humans are actively preventing succession from reaching the natural climax community in order to conserve a species currently present

If humans stopped creating plagioclimax communities…

Natural succession would proceed and the species being conserved would most likely be outcompeted as new species colonise

Managing succession techniques

Coppicing- cutting trees down to ground level

Mowing- removing any larger soecies keeping grass from overtaking an area

Grazing -letting livestock graze on larger species

Burning- used on moor habitats where larger plants are burned intermittently to stop them colonising

Animal populations - either remove or cull them if they are putting the species you are trying to conserve at risk

Population dynamics

Study of a size of population and how it changes over time, looking at why it may increase/decrease in relation to other organisms

Carrying capacity is

The maximum number of individuals an area can sustain without depleting resources

Intraspecific competition

Competition between members of the same soecies for limited resources

Dynamic population

One that changed in size over time

Once population reaches carrying capacity…

There will be more intraspecific competition as resources are limited so only strongest will survive which leads to decrease in population so then there are extra resources available so population increases again -repeating dynamic cycle

Density dependant factors

Describe selection pressures that are going to have a heightened effect as the population increases and lesser effect when it decreases -they depend on the population density

Eg. Disease and food availability as more individuals = more of an issue

Density independent factors

Are not reliant on the population density

Eg. Natural disaster as no matter how big the population they are going to be effected

Processes that alter the size of a population

Birth rate-

Death rate-

Immigration (movement into a population)

Emigration (movement out of a population)

R-strategies

Species that have extremely high birth rates, reach sexual maturity early on and very low parental care eg. Sea urchin that have high offspring mortality rates have lots of offspring to increase the probability

K-strategists

Have one or two offspring, don’t reach sexual maturity until later in their lifetime and use high parental care to ensure high offspring survival, are extremely vulnerable to over exploitation bc their breeding doesnt increased population loads eg. Blue whales

Predation

A selection pressure that affects the number of deaths a population experiences, predator population size should always remain lower than prey or there would be shortage of food and instead intraspecific competition would kill the weakest predator

Of prey increases there is more food so their population will increase shortly after and then decreases again because more numbers means less food

Maximum sustainable yield of a population

The maximum number of individuals that can be harvested that won’t deplete population size over time, calculated using birth/death rates, selection pressures eg predator numbers, and whether they are r/k strategists

Over exploitation

Harvesting numbers above the maximum sustainable yield, particularly affecting k-strategists

Quotas

Limits set on the number of individuals that can be harvested to ensure population recovery, must be below maximum sustainable yield

Ecological monitoring

Collecting data on species and populations to inform conservation efforts

Population dynamics

Features of a population that need to be studied including size, distribution, survival rate and age structure

Size of population

Number of individuals in a population which should be large enough to sustain numbers without depletion over time

Distribution throughout habitat

Extent to which a species occupies an area which affects vulnerability to threats

Survival rate

Number of individuals dying per set amount of time including natural deaths predator attacks or illness

Age structure of population

Proportion of individuals in different age groups within a population which affects vulnerability to extinction

Imagery in monitoring

Use of technology to capture images of individuals and their their surroundings for tracking and data collection

Image databases

Collections of images used to recognise and track individuals in a population, providing information on territory size, movement, lifespans, and social interactions

Tracking collars/tags

Devices used in conjunction with imagery to identify individuals when unique features are lacking

Motion sensitive cameras

Cameras positioned in a habitat that begin recording when motion triggers them, capturing photos of individuals

Closed circuit television (CCTV)

Continuous recording using cameras to monitor animals vulnerable to disturbance by researchers often used for bird nests

Marking individuals

Using collars, leg rings, ear tags, to identify individuals and track their movements and behaviours

Radio tracking

Technology where a device emits radio waves tracked by a satellite to monitor an individuals location

GPS tracking

Technology that monitors an indivisos position based on location, velocity, elevation to provide precise location data

DNA databases

Databases used to identify individuals and assess the size of a populations gene pool, determining vulnerability to extinction

eDNA (environmental DNA)

DNA samples collected from the environment such as water or soil used to identify soecies presence and assess genetic relationships

Auditory devices

Devices used to listen and record sounds of vocal species particularly useful for soecies not often seen like bats

Satellite data collection

Use of satellites to collect large amounts of data quickly and continuously allowing analysis of landscape and vegetation distribution

Data loggers

Handheld devices or mounted carriers used to measure abiotic factors like light intensity, temp, wind speed and humidity

Remotely operated vehicles (ROVs)

Devices like drones controlled by someone to collect data from hard to reach areas

Autonomous unmanned vehicles (AUVs)

Devices that do not require constant control to collect data from various environments

Aircraft

Vehicles like planes used to collect data from the air but limited by fuel constraints and need for pilots and crew

Balloons

Devices used to collect data from different heights in the atmosphere providing a range of environmental info

Non-technological methods

Methods of identifying soecies presence in an area without the use of technology including nests/burrows, droppings, and tracks

Artificial population control

Intervention to artificially control the population through culling may be required to enable the soecies or habitats to survive where natural control mechanisms no longer regulate the population eg. If breeding rate is low, captive breeding and release programmes are used

Taxonomy

The science of grouping organisms according to the similarities in their features but is mostly subjective

Ecological niche

The ecological niche of a soecies is the role that it plays in its habitat including the way it uses environmental resources

Ecosystem

The combination of the biotic and abiotic features of an area. Eg. Coral reef

Biome

Large geographical region with specific climatic conditions within which a characteristic community of species lives eg. Tropical rainforest, temperate rainforest

Confusion between ecosystems and biomes

Biome includes all the area covered by the same community of species, while ecosystems each have a different isolated area, all coral reefs belong to the same coral reef biome

Biosphere

all of planet earth that is inhabited by living organisms including the land surface, soil, water, and atmosphere