Important words and concepts
from Chapter 53, Campbell & Reece, 2002 (3/25/2005):
by Stephen T. Abedon (abedon.1@osu.edu)
for Biology 113 at the Ohio State University
|
|
Course-external links are
in brackets Click [index] to access site index Click here to access
text’s website Vocabulary
words
are found below |
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(1) Chapter title: Community Ecology
(a)
[community ecology (Google Search)]
[index]
(a)
A community consists of all of the organisms living within a certain
geographical area
(b)
These organisms include conspecifics as well as members of other
species
(c)
These organisms interact with each other both directly and indirectly
(d)
Numerous (pessimists might say "endless") parameters affect
what species are present and in what abundance
(e)
"Simple generalizations can rarely explain why certain species
commonly occur together in communities."
(f)
"The distributions of most populations in communities are probably
affected to some extent by both abiotic gradients and interactions [with other
species]."
(g)
[community and ecology
-"community ecology" (Google Search)]
[index]
(a)
Not only do the abiotic and biotic components of an ecosystem impact on
what species are present and in what abundance, but species also are modified
by their interactions with other species
(b)
Coevolution represents the evolutionary modification of organisms in
response to other organisms, particularly when two organisms are mutually
modified in response to modifications displayed by the other
(i)
E.g., a flower population better attracts certain insects which in turn
evolve to better exploit the flower population
(ii)
E.g., faster rabbits select for faster coyotes which in turn select for
faster rabbits
(c)
"In its broadest sense, coevolution is the term used to describe
more complex interactions involving reciprocal evolutionary adaptations in two
species: A change in one species acts as a selective force on another species,
and counteradaptation by the second species, in turn, is a selective force on
individuals in the first species. Coevolution has been studied most extensively
in predator-prey
relationships and in mutualism."
(d)
"It is difficult to sort out the importance of the various
selective forces, and the simple idea of coevolution as
adaptation-counteradaptation occurring exclusively between two species does not
often adequately describe the interactions within communities."
(e)
"Despite the problems in assessing cause and effect in the
evolution of complex ecological relationships, biologists agree that the
adaptation of organisms to other species in a community is a fundamental
characteristic of life. Put another way, interactions of species in ecological
time often translate into adaptations over evolutionary time."
(f)
Strictly, however, coevolutionary relations may be limited to
interactions between two species rather than modifications that affect a suite
of species; for example, an ability to run faster in order to escape predators
is not quite the same thing as an ability to run faster in order to escape one
predator species (which, if it wants a meal, would then be exposed to selection
to run even faster); this narrowing limits the applicability of the idea of
coevolution since it creates a criteria that is stricter then simply more
effectively interacting with other species in terms of survival and
reproduction
(g)
[coevolution (Google Search)]
[index]
(4) Interspecific interactions
(a)
Coevolution is one consequence of a more general category of ecology
called interspecific interactions (between-species interactions)
(b)
Previously we considered intraspecific interactions,
i.e., those between very similar organisms, conspecifics
(c)
Interspecific interactions range from those between fairly similar
organisms to those between very dissimilar organisms
(d)
A key distinction between intraspecific and interspecific interactions
is that the former but not the latter share a gene pool;
(i)
intraspecific interactions do not generally lead to the extinction of a
species
(ii)
In interspecific interactions, losers can go extinct
(e)
Interspecific interactions include symbioses and can be categorized as
(i)
Predation/parasitism (+/-)
(ii)
Competition (-/-)
(iii)
Commensalism (+/0)
(iv)
Mutualism (+/+)
(f)
The plusses and minuses are a notation employed by your text indicating
the relative gain each participant obtains from the interaction
(g)
See Table 53.1,
Interspecific Interactions
|
Interspecific Interactions |
|
|
+ / o |
Commensalism |
|
+ / + |
Mutualism |
|
+ / - |
Parasitism Parasitoidism Herbivory |
|
+ / - - |
Predation |
|
- / - |
Competition |
(h)
[interspecific interaction
(Google Search)]
[index]
(a)
Commensalism is a relatively unexploited interspecific interaction
(b)
The reason for this has as much to do with its definition as anything,
i.e., commensalism is a relationship in which one member gains but the other
member neither gains nor loses; this places commensalism on a knife's edge
between predation and mutualism
(c)
If the "unaffected" individual is indeed affected, even just
a little, then the relationship can no longer, technically, be termed
commensalism
(d)
In the real world it is essentially impossible to determine whether the
"unaffected" member really is unaffected, so the concept is difficult
to apply
(e)
Nevertheless, in absence of evidence for mutualism or predation
then an assumption of commensalisms is a reasonable one
(f)
[commensalism (Google Search)]
[index]
(a)
Mutualisms, while not necessarily as common as predation or interspecific competition, are still enormously common
(b)
This makes some sense since a mutualistic relationship is one in which
both members gain
(c)
However, it is likely that most mutualistic relationships started out,
in evolutionary time, as exploitative (+/-) relationships which somehow were
co-opted into less exploitative relationships
(d)
Examples include everything from lichens, to bees and flowers, to
mitochondria and the already lectured on eucaryotic cell
(e)
[mutualism (Google Search)]
[index]
(7)
Predation
(a)
+/- interactions include
(i)
Predation
(ii)
Parasitism
(iii)
Parasitoidism
(iv)
Herbivory
(b)
These interactions all involve
(i)
one individual killing and then eating the other fully (predation)
(ii)
not killing and then eating the other partially (parasitism and
herbivory), or
(iii)
letting one's offspring do the eating (parasitoidism)
(c)
Note that an additional kind of +- interaction does not involve eating
but instead is the stealing of some non-food a resource from one individual by
the other: vines on trees, for example, or a cow bird's brood parasitism
(d)
[predation (Google Search)]
[index]
(a)
Prey organisms display numerous defenses against predation
(b)
That is, there exist a number of defenses
against + / - - (as well as + / -) interactions:
(i)
Secondary compounds (plants)
(ii)
Nutritional deficiencies (plants)
(iii)
Mechanical defenses (plants)
(iv)
Production of poisons (animals)
(v)
Mechanical defenses (animals)
(vi)
Running away & hiding (animals)
(vii)
Fighting back (mostly animals)
(viii)
Cryptic coloration (mostly animals)
(ix)
Batesian mimicry (animals)
(x)
Müllerian mimicry (animals)
(xi)
Immune systems (animals)
(c)
[in order for a predator to obtain benefit from prey they have to
encounter prey (i.e., be in close proximity), then detect prey (i.e., notice
that they currently are in close proximity), then capture prey, then
successfully consume the prey, and then successfully derive nutrient benefit
from the prey, and minimally more benefit must be derived than the costs of
capturing and consuming the prey – hence, it is to the potential prey’s
benefit, as an individual or as a population, to minimize their numbers so as
to be rare and therefore rarely found by predators, to be cryptic in both
coloration and behavior, to be capable of escaping if noticed, to be difficult
to consume or to digest, and to not supply necessary nutrients or to be toxin
to the predator in some manner]
(d)
[defence against predation
(Google Search)]
[index]
(9) Plant defenses against predation
(a)
Of course, plant predators are called herbivores
(b)
Typically a plant (and other stationary organisms) will not manage to
achieve complete avoidance of predation, but instead will limit their own
predation to those organisms that possess appropriate morphological or
biochemical adaptations
(c)
It is important to keep in mind that herbivores can be big (cows) as
well as small (insects, fungi, bacteria) so more than one defense is typically
necessary to defeat all possible predators
(d)
Of course, plants also tend to be eaten in pieces rather than as a
whole organism, so anything a plant can do to spare part of the plant from
being eaten can also be advantageous (this rule apparently is also true in
terms of defenses against lawn mowers)
(e)
Plant defenses against predation include
(iii)
Mechanical defenses
(f)
[plant defences (Google Search)]
[index]
(a)
(b)
One role of secondary compounds are as defenses against predation,
e.g., toxins
(c)
What is toxic to one herbivore may be useful to another; particularly
humans take great advantage of plant secondary chemicals using them as drugs
(both recreational and medicinal), spices, etc.
(d)
Some animals (e.g., monarch butterflies) can actually incorporate these
toxins into themselves to make themselves unpalatable to some of their own
predators
(e)
[secondary compounds
(Google Search)]
[index]
(a)
Plants additionally tend to lack certain nutrients (e.g., essential
amino acids)
(b)
Such nutritional deficiencies force predators to diversify what plants
they consume, thus preventing herbivores from getting too good (specialized) at
exploiting a particular plant species
(c)
[(Google Search)]
[index]
(a)
(b)
Thorns prevent larger things from comfortably eating a plant, while
hairs and other small appendages can keep small things from reaching the plant
(c)
This the trunk of a honey locust displaying its multibranched, red
thorns à
(d)
Plants also interfere with chewing by, essentially, being less than
succulent, e.g.,. the shell of a nut or silica deposited in the leaves of grass
(e)
(between nutritional deficiencies, mechanical defenses, and secondary
compounds one speaks of low forage quality and it is plants that represent
low-quality forage that tend to accumulate when herbivore pressures are high,
i.e., high animal to plant ratios)
(f)
[mechanical defenses
(Google Search)]
[index]
(13) Animal defenses against predation
(a)
Animals are a little bit more versatile behaviorally when it comes to
defending themselves against predation
(b)
For example, animals can
(i)
Run and hide (particularly the latter aided by cryptic coloration)
(ii)
Produce poisons that make them unpalatable
(iii)
Employ morphological adaptations that interfere with consumption
(iv)
Fight back using both morphological and chemical defenses (some plants,
too, can fight back using, for example, actively sprayed chemical defenses)
(v)
Not looking like prey (cryptic coloration)
(c)
[animal defenses (Google Search)]
[index]
(a)
(b)
["Camouflage, called cryptic coloration, is the quintessential
passive defense, making potential prey difficult to spot against its
background. A camouflaged animal need only remain still on an appropriate substrate
to avoid detection."]
(c)
See Figure 53.5, Camouflage: a canyon tree frog disappearing into a
background of granite
(d)
[cryptic coloration
(Google Search)]
[index]
(a)
A different approach is to taste bad (or be unpalatable for various
other reasons) and to advertise this
(b)
Aposematic coloration is how organisms advertise unpalatableness, at
least visually (humans, or course, display a distinct bias in terms of sensory
input hence we tend to notice the visual displays by animals much more so than,
for example, the olfactic displays – notice that since birds display the same
bias we often interpret these visual displays in terms strategies that
interfere with predation by birds)
(c)
For example, the black and yellow stripes on bees represent aposematic
coloration, and it works!
(d)
Aposematic coloration is so successful, in fact, that it gives rise to
mimicry
(i)
Batesian mimicry
(ii)
Müllerian mimicry
(e)
See Figure 53.6, Aposematic (warning) coloration of a poison-arrow frog
(f)
[aposematic coloration
(Google Search)]
[index]
(a)
Batesian mimicry is the tendency of palatable and otherwise succulent
prey species to pretend to be unpalatable by looking like unpalatable species
(b)
This works to a point, but limits the size of the mimic's population
since once mimics are sufficiently prevalent, predators will catch on to the
mimicry
(c)
However, when their numbers are sufficiently few, the mimic gains from
protection from predation while simultaneously not putting out the resources
needed to achieve lack of palatability, etc.
(d)
See Figure 53.7, Batesian mimicry
(e)
[Batesian mimicry (Google Search)]
[index]
(a)
(b)
Such mimicry increases the representation of lack of palatableness
among potential prey associated with a given form of aposematic coloration
(c)
Note that both Batesian and Müllerian mimicry can occur simultaneously
with the same aposematic coloration within the same communities (i.e., a group
a similarly marked organisms, some of which are harmless and others which are
not)
(d)
See Figure 53.8, Müllerian mimicry
(e)
[Mullerian mimicry, Müllerian mimicry (Google Search)]
[index]
(18) Predation and species diversity (keystone species)
(a)
Another way that two directly competing species can achieve coexistence
results from predation
(b)
A predator typically feeds on more than one species
(c)
By doing so, they serve to keep the populations of both species below
the sizes one or both could attain in the absence of predation (i.e., below carrying capacity)
(d)
This can allow both competing species (i.e., the prey) to coexist,
especially if the weaker competing species happens to be better at escaping
predation
(e)
Additionally, optimal foraging
can result in prey caught and consumed as a function of their population densities such that predation
maintains prey diversity by frequency-dependent effects in the same manner that
frequency-dependent selection can maintain
a balanced polymorphism
(f)
One can describe a predator whose presence has a profound impact on the
species diversity of a given community as a keystone species
(g)
[predation and "species
diversity" (Google Search)] [index]
(19) Interspecific competition
(a)
Interspecific competition represents a lose-lose interaction (-/-), that
is, both species are less able to convert resources into progeny because the
other species is laying claim to the same resources
(b)
Note that this is an unstable situation that will tend to select for
either better means of acquiring the contested resources, or a switching to a
different resource
(c)
Additionally, note that while a competing species may be more effective
in exploiting any given resource, conspecifics will always be competing with
any given individual for a larger variety of resources than will interspecifics
(d)
Thus, growth of a given species may be limited by both conspecifics
(intraspecific competition/density-dependent factors)
and interspecific competition (a density-independent factor)
(e)
“Expression” of the costs of interspecfic
competition include:
(i)
Competitive exclusion
(ii)
Resource partitioning
(iii)
Character displacement
(iv)
Fundamental vs. Realized Ecological Niche
(f)
[interspecific competition
(Google Search)]
[index]
(20) Interference competition
(supplemental discussion)
(a)
Interspecific competition that involves actual
interspecific fighting is termed interference competition
(b)
[interference competition
(Google Search)]
[index]
(21) Exploitative competition
(supplemental discussion)
(a)
Interspecific competition which involves no
fighting but instead a co-usage of one or more resources is termed exploitative
competition
(b)
Below we will consider the potential consequences of exploitative
competition within communities
(c)
[exploitative
competition, exploitation
competition (Google
Search)] [index]
(a)
"Two species with similar requirements (cannot) coexist in the
same community; one species would inevitably harvest resources and reproduce
more efficiently, driving the other to local extinction. Even a slight
reproductive advantage would eventually lead to the elimination of the inferior
competitor and an increase in the density of the superior one."
(b)
This is the competitive exclusion principle
(c)
Two populations with very similar needs, living sympatrically, will be in too great a
competition with each other to coexist, unless both populations are the same
species (in which case, of course, they wouldn't be two separate populations)
(d)
Competitive Exclusion
Similarly, two
populations can coexist if their needs sufficiently differ
(e)
[competitive exclusion
(Google Search)]
[index]
(a)
Extinction of one of two populations living sympatrically and competing over too many
resources is not the only possible outcome of interspecific competition
(b)
An alternative outcome is the evolution of a divergence of resource needs
(c)
Such a divergence is called resource partitioning, and is simply the
ecological version of the idea that it is often easier to switch than it is to
fight
(d)
See Figure 53.3, Resource partitioning in a group of lizards
(e)
[resource partitioning
(Google Search)]
[index]
(a)
Character displacement is presumably a consequence resource partitioning
(b)
"The tendency for characters to be more divergent in sympatric populations of two species than allopatric population of the same two species
is called character displacement."
(c)
That is, characters diverge presumably in response to interspecific
competition, but do not diverge in populations not subject to the same
interspecific competition
(d)
Thus, the character differs between the population undergoing
interspecific competition and the population not undergoing interspecific
competition
(e)
See Figure 53.4, Character displacement: circumstantial evidence for
competition in nature
(f)
[character displacement
(Google Search)]
[index]
(a)
What is being fought over in interspecific competition is various
aspects of the ecological niche
(b)
A niche is the sum total of what an organism does in its environment,
including all of the resources consumed
(c)
[ecological niche (Google Search)]
[index]
(a)
All of the resources a population could exploit under ideal conditions,
where there exists no interspecific competition, is termed the fundamental
niche of an organism
(b)
The fundamental niche basically represents as good as things can get
for an organism
(c)
A population able to exploit its fundamental niche would be able to
achieve its maximal population size
(d)
[fundamental niche (Google Search)]
[index]
(a)
Nothing, of course, is perfect, and the fundamental niche
represents perfection to the exploiting population
(b)
In the real world, populations do not have access to all of the
resources they could possibly exploit
(c)
Such a limitation on resource acquisition is termed a realized niche,
i.e., what resources a population can exploit in a real environment,
particularly one in which interspecific competition
occurs
(d)
[realized niche (Google Search)]
[index]
(a)
Trophic structures are the feeding relationships within communities and
therefore within ecosystems, that is, who's eating whom
(b)
[trophic structure (Google Search)]
[index]
(a)
Trophic levels refer to how far removed from the original source of
energy an organism is within a trophic structure
(b)
[trophic level (Google Search)]
[index]
(a)
The first trophic level is made up of the primary producers, the
organisms that obtain from inorganic sources the energy that powers
ecosystems
(b)
Primary producers typically are photosynthetic organisms
(c)
More generally, primary producers are autotrophs (i.e., they fix
CO2)
(d)
[primary producer (Google Search)]
[index]
(a)
Consumers are the heterotrophs, i.e., organisms that obtain their
carbon from other organisms
(b)
The typical consumer is a chemoheterotroph that consumes other
organisms or parts of other organisms to obtain their carbon and energy
(c)
[in addition to the types of consumers listed below we can also speak
of omnivores, i.e., consumers that eat at different trophic levels including
consuming producers and detrivores, which are consumers that consume detritus
which is the broken up remains of organisms]
(d)
[ecosystem consumer,
ecology consumer,
omnivore, detrivore (Google Search)]
[index]
(32)
Primary consumer (herbivore)
(a)
A primary consumer is a consumer that eats primary producers
(b)
Primary consumers are called herbivores
(c)
[primary consumer, herbivore (Google Search)]
[index]
(33)
Secondary consumers (carnivore)
(a)
Secondary consumers eat primary consumers
(b)
[secondary consumer,
carnivore (Google Search)]
[index]
(a)
Tertiary consumers eat secondary consumers
(b)
[tertiary consumer (Google Search)]
[index]
(a)
Decomposers consume the waste given off by living organisms or the
remains of dead organisms which they did not kill
(b)
"The organic material that composes the living organisms in an
ecosystem is eventually recycled, broken down and returned to the abiotic
environment in forms that can be used by plants. Decomposers, which feed on
nonliving organic material, are key to this recycling process. The most
important decomposers are bacteria and fungi, which first secrete enzymes that
digest organic material and then absorb the breakdown products; some can even
digest cellulose."
(c)
"In fact, all heterotrophs, including humans, are decomposers in
the sense that they break down organic material and release inorganic products,
such as carbon dioxide and ammonia, to the environment."
(d)
[decomposers (Google Search)]
[index]
(a)
A simplification of the trophic structure of an ecosystem is the food
chain
(b)
Food chains refer to the passage of nutrients and energy from a primary
producer to a primary consumer to a secondary consumer, and so on
(c)
Food chains are usually a simplistic representation because they assume
that a given organism consumes only one kind species and that the predators of
any given consumer also consume only one kind of species
(d)
See Figure 53.10, Examples
of terrestrial and marine food chains
(e)
[food chain (Google Search)]
[index]
(a)
Far more realistic is the concept of food webs
(b)
Food webs are like food chains but more realistic, i.e., allowing for
species to consume more than one other kind of species
(c)
In addition, food webs allow individual species to consume at more than
one trophic level
(d)
For example, humans consume primary producers (e.g., soy beans),
primary consumers (e.g., cows), and secondary (or higher) consumers (e.g.,
salmon)
(e)
[The food webs you see here are
grazing food chains since at their base are producers which the
herbivores then graze on. While grazing food chains are important, in nature
they are outnumbered by detritus-based food chains. In detritus-based
food chains, decomposers are at the base of the food chain, and sustain the
carnivores which feed on them. In terms of the weight (or biomass) of animals
in many ecosystems, more of their body mass can be traced back to detritus than
to living producers. – Mr. Kousen’s Biology]
(f)
See Figure 53.11, An
Antarctic marine food web
(g)
[food web (Google Search)]
[index]
(a)
One thing that limits the carrying capacity
for many organisms is that the presence of these organisms essentially spoils
the environment for their continued presence
(b)
Such organisms typically are r-selected, and essentially are good at
finding environments they can exploit, exploiting those environments, then
giving way to organisms which are better at hanging on in those environments
(c)
The exploitation of an environment by one population, followed by the
exploitation by a second (third, etc.) population is termed ecological
succession
(d)
"Many of the changes in community structure during succession may
be induced by the organisms themselves. Direct biotic interactions may be
involved, including inhibition of
some species by others through exploitative competition, interference
competition, or both. The presence of organisms also affects the abiotic
environment by modifying local conditions. This may result in facilitation, in which the group of
organisms representing one stage 'paves the way' for species typical of the
next stage . . . Sometimes the changes that facilitate the development of a
later stage actually make the environments unsuitable for the very species
responsible for the changes."
(e)
Ecological succession continues in a habitat until species, typically K-selected, that are good at nurturing
their young within the same environment (as well as good at excluding other
species) comes to dominate the environment, or until catastrophic change
essentially wipes the slate clean, making an environment once again exploitable
to the r-selected populations
(g)
[ecological succession
(Google Search)]
[index]
(a)
Ecological succession typically occurs in
fairly well-defined waves of succeeding organisms
(b)
When the environment being exploited is essentially lifeless—lacking in
both living organisms and in their remains—then the first round of exploitation
is termed primary succession
(c)
Primary succession occurs, for example, following volcanic or glacial
destruction of an environment
(d)
The first organisms that exploit an otherwise lifeless terrain are
termed primary successors
(e)
Primary succession is a fairly rare occurrence especially relative to
the much-more familiar secondary succession that we observe in
disturbed habitats all around us
(f)
[primary succession
(Google Search)]
[index]
(a)
Secondary succession is succession that follows primary succession,
i.e., of an environment that already contains life (or, at least, soil)
(b)
"Because resource availability changes over the course of
succession, different species compete better at different stages. Early stages
are typically characterized by r-selected species that are good
colonizers because of their high fecundity and excellent dispersal mechanisms.
Many of these may be described as ‘fugitive’ or ‘weedy’ species that do not
compete well in established communities, but maintain themselves by constantly
colonizing newly disturbed areas before better competitors can become
established in the same places."
(c)
[secondary succession
(Google Search)]
[index]
(a)
The community within an ecosystem that exists following ecological succession is termed the climax community
(b)
A climax community is made up of organisms that are good at reproducing
in the face of interspecific competition
(c)
"At the climax stage, environmental conditions are such that the
same species can continue to maintain themselves. For example, the
[maple-beech] forest (image, below) that is the climax stage of old-field
succession [in much of Ohio] maintains the moist, shaded environment that
allows offspring of these species to grow, while inhibiting most of the species
typical of earlier stages of succession."
(e)
Climax communities will remain in place until either the climate
changes, a better competitor arrives, or the community is catastrophically
disrupted, e.g., by fire or, more recently, by extensive logging; the image
that follows are of typical logging roads up a steep hillside (these are found
all over the Pacific Northwest):
(g)
[climax community (Google Search)]
[index]
(a)
In order for an ecosystem to go through succession, the organisms in
each wave of succession must be available in the local environment
(b)
The farther an ecosystem is from a source of these organisms, the less
likely these organisms will be present and therefore that succession will occur
(c)
The smaller an island is, the less likely that species will find their
way to the island and the more likely that species present on the island will
go extinct (due to smaller size and due to resultantly smaller populations,
respectively)
(d)
This can be seen most obviously on islands: the farther an island is
from a source of organisms, the less likely the given organisms will find their
way to the island
(e)
The flip side is that as a consequence of, if nothing else, random
extinction, the smaller an ecosystem is, the less able it is to hold on to the
species that it has
(f)
Thus, the farther an island or ecosystem is from other islands or ecosystems,
and the smaller the island or ecosystem, the more impoverished of species
either is likely to be
(g)
See Figure 53.26, The hypothesis of island biogeography
(h)
(i)
In other words, eventually if we convert every last forest into
farmland, housing tract, or parking lot, the remnants of ecosystems will be so
small that they will be unable to sustain what species they start with, and
ecosystems will be so far apart that they will be unable to reacquire species
from similar ecosystems
(j)
This essentially, ultimately represents a genetic bottlenecking of the
entire world, and if the goal of humans is to survive past this environmental
disaster of our own making, then the big losers will most definitely be
ourselves
(k)
Or, to paraphrase George Carlin, If we're so smart, why are we peeing
in our water bowl?
(l)
[island biogeography
(Google Search)]
[index]
(a)
Animal defenses against predation
(c)
Batesian mimicry
(d)
Carnivore
(f)
Climax community
(g)
Coevolution
(h)
Commensalism
(i)
Community
(k)
Consumers
(m)
Decomposers
(o)
Ecological niche
(q)
Food chain
(r)
Food web
(t)
Herbivore
(v)
Interspecific interactions
(x)
Keystone species
(aa)
Mutualism
(cc)
Plant defenses against predation
(dd)
Predation
(ee)
Predation and species diversity
(ff)
Primary
consumer
(gg)
Primary producer
(hh)
Primary succession
(ii)
Realized niche
(kk)
Secondary compounds
(ll)
Secondary
consumers
(nn)
Secondary succession
(oo)
Tertiary
consumers
(pp)
Trophic level
(qq)
Trophic structure