(2)
Competition for resources by both plants and animals
All organisms need a variety things from their
environment and other organisms to survive and reproduce (and
therefore evolve to be better adapted to their habitat).
Organisms can only survive if they have enough
resources for their needs - individual growth and collective
reproduction. Within the same ecosystem and its habitats ...
... animals will compete for food,
water, territory (e.g. for hunting or gathering food) and
mates to produce the next generation,
... and plants will compete for light
for photosynthesis, nutrient mineral ions in the soil,
space to grow, and water for transport-transpiration
and photosynthesis.
Within an ecosystem, animals and
plants that get more of the resources from their environment, are more
likely to be successful than those organisms that get less.
Successful organisms are more
likely to survive and pass on their 'successful genes' in
reproduction.
Animals who have with a wider
range of food sources are more likely to survive than those e.g.
might rely on one food source - if this was affected, such animals
are less likely to survive or move to another location.
Most animals can, and will move
to, wherever food is available.
Changes in the environment can cause the
distribution of organisms to change - meaning a change in where members
of a population live.
Plants, the primary food producers at the base of many
food
chains, need light, mineral ion nutrients, space to grow, water and
oxygen and carbon dioxide from the atmosphere.
See
biomass - food chains
Animals need food and oxygen, mates for reproduction, water and space to
live in (the 'territory' of their habitat).
The size of a population is limited by competition
for these resources as well as pre-predator relationships.
One organism can outcompete another give increases
and decreases in populations, sometimes in complex cycles.
Types of competition
Interspecific competition is
competition between different species e.g. red and grey
squirrels.
Generally speaking animals try to avoid
competing with others, more chance of all surviving, but
competing for the same resources will affect the size and
distribution of their populations.
Intraspecific competition is
competition between members of the same species e.g. an
animal competing for its own territory and mates - a lot of effort
can be put in by a male to attract a female including displays of
colour/showing off and fighting competitors!
Organisms may compete with other species or with members of their own
species for the same resources in the same habitat.
Different predators might compete for the same prey.
e.g. in the oceans sharks and dolphins compete for the same
shoals of smaller fish.
Animals might compete for the same plant food.
e.g. red and grey squirrels compete for
the same food like nuts in the same woodland habitat. Grey
squirrels compete more strongly-efficiently for food resources,
depleting them to the point where red squirrel population drop
to zero
unless managed in protected areas.
'Winners and losers'
If competing species are not perfectly
matched, eventually one will become more successful than the other.
The less successful species may:
Be unable to do anything and become
extinct.
Remain in its original habitat and adopt a
different survival strategy.
More to another area and find a new
habitat and suitable resources.
In general in any ecosystem "the survival
of the fittest' determines which the population is stable.
In many respects humans are very successful
organisms, we are intelligent and adaptable, exploiting and competing
with many plants and animals across every continent.
Key points
Based on
the syllabus-specifications for students taking the AQA, Edexcel and OCR
GCSE level biology examinations (~US grades 9-10).
Key
ideas in understanding competition between plants or animals for resources in an
ecosystem
Types of
Competition for Resources in Ecosystems
Competition is a
fundamental ecological interaction where organisms vie for limited
resources necessary for survival and reproduction.
It can be classified into
two main types: interspecific competition (between
different species) and intraspecific competition
(within the same species). Both types play crucial roles in shaping
ecosystems and influencing population dynamics.
1.
Interspecific
Competition
Interspecific competition
occurs between individuals of different species that
require similar resources in an ecosystem.
This type of competition can
impact species distribution, abundance, and even drive evolutionary
adaptations.
Examples of
Interspecific Competition
-
Plants:
Different plant species may compete for sunlight, water,
nutrients, and space. Taller trees can overshadow smaller
plants, reducing their access to light.
-
Animals:
Carnivores such as lions and hyenas compete for prey, while herbivores
like deer and cattle may compete for grazing land.
Effects of
Interspecific Competition
-
Competitive
Exclusion Principle: One
species may outcompete another to extinction if they occupy the same
ecological niche.
-
Resource
Partitioning: Some species
adapt to use resources differently to reduce direct competition, leading
to specialization.
-
Impact on
Biodiversity: Strong
interspecific competition can limit species diversity in an ecosystem.
2.
Intraspecific
Competition
Intraspecific competition
occurs between individuals of the same species competing
for identical resources.
This type of competition is often more intense
because the competitors have identical needs.
Examples of
Intraspecific Competition
-
Plants:
Trees in a dense forest compete for sunlight, water, and
nutrients. Some may grow taller while others struggle for
survival.
-
Animals:
Wolves compete for territory and food, while male deer battle for mates
during the breeding season.
Effects of
Intraspecific Competition
-
Population
Regulation: Limits
population size, preventing overcrowding and resource depletion.
-
Natural Selection:
Encourages stronger individuals to survive and pass on advantageous
traits.
-
Territorial
Behaviour: Many species
establish territories to reduce competition and ensure access to
resources.
3.
Importance in
Understanding Ecosystems
Competition plays a vital role
in ecosystem stability and evolution.
Key impacts include:
-
Maintaining
Balance: Prevents
overpopulation and ensures resources are not exhausted.
-
Driving
Adaptations: Leads to
physiological and Behavioral changes that enhance survival.
-
Influencing
Succession: Determines
which species dominate an area over time.
Understanding competition
helps ecologists predict species interactions and
ecosystem changes, making it a crucial concept in
biology.
Summary of learning objectives and key words or phrases
Be able to describe and understand the significance of
various types of competition for resources by both plants and
animals including interspecific competition and intraspecific competition
examples.
WHAT NEXT?
TOP OF PAGE
INDEX
of biology notes on ecosystems
Big website and use [SEARCH
BOX] below, maybe quicker than the indexes
INDEX of all my BIOLOGY NOTES
HOME PAGE of Doc Brown's Science
website
UK KS3 Science Quizzes for
KS3 science students aged ~11-14, ~US grades 6, 7 and 8
Biology * Chemistry
* Physics UK
GCSE level students aged ~14-16, ~US grades 9-10
Advanced Level Chemistry
for pre-university age ~16-18 ~US grades 11-12, K12 Honors
Find your GCSE/IGCSE
science course for more help links to all science revision notes
email doc
brown - comments - query?
Doc Brown's school biology revision notes: GCSE biology, IGCSE
biology, O level biology, ~US biology science grade 8, grade 9 and
grade 10 school science courses or equivalent for ~14-16 year old students of
biology IGCSE AQA GCSE Biology Edexcel GCSE Biology IGCSE OCR Gateway Science
Biology OCR 21st Century Science Biology Some of these biology revision notes
might be suitable for UK KS3 Science-Biology courses for ages 12-14 (~US biology
science grades 6, grade 7 and
grade 8),
Explaining importance of
ecology - competition for resources by plants & animals
in GCSE level biology, What you need to know about ecology - competition
for resources by plants & animals for
GCSE level
biology,
Explaining use of ecology - competition for resources by plants &
animals knowledge in GCSE level biology, Examples of ecology - competition for
resources by plants & animals explained when studying GCSE level biology, What
is the significance of ecology - competition for resources by plants & animals
in GCSE level biology, describing
explaining theory of ecology - competition for resources by plants &
animals when studying GCSE level biology, exam revision notes for ecology -
competition for resources by plants & animals, online help for understanding
ecology - competition for resources by plants & animals in GCSE
biology, what do I need to learn about ecology - competition for
resources by plants & animals? what do I need to know about ecology -
competition for resources by plants & animals for GCSE biology exams, how to prepare for questions on
ecology - competition for resources by plants & animals in GCSE
biology examination? ecology - interspecific competition & intraspecific
competition for
syllabus-specifications
for students taking the IGCSE/GCSE level biology examinations, summary
revision notes key points on ecology - interspecific competition & intraspecific
competition for students studying AQA
igcse/gcse biology notes on ecology - interspecific competition & intraspecific
competition, Edexcel gcse
biology notes on ecology - interspecific competition & intraspecific
competition, OCR 21st century GCSE
biology notes on ecology - interspecific competition & intraspecific
competition, OCR gateway
GCSE biology notes on ecology - interspecific competition &
intraspecific competition, WJEC gcse biology notes on ecology - interspecific
competition & intraspecific competition, CCEA gcse biology notes on ecology -
interspecific competition & intraspecific competition, CIE Cambridge igcse
biology, notes on ecology - interspecific competition &
intraspecific competition useful for US grade 9-10 biology student courses
