W7 Range limits Niches and Adaptation

Question 1

what research question does the transplant experiment corresponds to?

Answer 1

why is a species absent in some places and present in other places? So why not transplant species to a different region?

Question 2

what is the salmon case study about?

Answer 2

why not transplant these commercially-valuable fish to a different region? Rainbow trout have been introduced all over the world and was successful in many places but not salmons. Sockeye salmon have been introduced in many places (france, denmark, mexico, argentina) but did not survive there.

Question 3

what does the transplant experiment test for?

Answer 3

whether the geographic distribution of species is limited due to dispersal barrier (so if dispersal barrier determines the range)

Question 4

how does the transplant experiment work?

Answer 4

we move individuals of a given species outside their native geographic range, and we determine whether they can survive and reproduce in the new environment

Question 5

what are the experiment, observations and conclusions?
1. transplant experiment
2. slightly better transplant experiment
3. a good transplant experiment

Answer 5

1. transplant experiment
   - experiment: transplant n native plants of species x outside its native range, monitor survival for 2 weeks
   - observation: all plants die within two weeks when transplanted outside the native range
2. slightly better transplant experiment
   - experiment: Transplant n native plants of species x outside its native range AND Transplant n native plants of species x inside its native range, monitor survival for two weeks
   - observation: all plants die when transplanted
   - conclusion: our method of transplantation kills plants

• observation: plants transplanted outside the native range live at the same rate as transplants within the range
• conclusion: may suggest geographic barrier, may suggest that 2 weeks is not long enough; it should be an entire life cycle considering triliums have a very long life cycle therefore should transplant triliums at different life stage

3. a good transplant experiment
   - experiment: Transplant n native plants of species x outside its native range AND Transplant n native plants of species x inside its native range, MONITOR GROWTH, SURVIVAL + REPRODUCTION OVER ENTIRE LIFE CYCLE
   - observation: plants transplanted outside the native range reproduce at a lower rate than transplants within the range
   - conclusion: range limited by environmental conditions or species interactions outside the range (depends on design)

Question 6

what is the key concept in the slightly better transplant experiment and in the better transplant experiment ?

Answer 6

slightly better transplant experiment:
- key concept is experimental controls, which allows us to estimate whether our manipulation had an effect on the outcome of interest (here in this transplant experiment, survival)

better transplant experiment:
- key concept here is monitoring growth, survival, and reproduction for at least a full life cycle is more likely to inform to what extent the species is able to persist outside its native range

Question 7

whether a species can persist a new area depends on its ____?

Answer 7

niche

Question 8

what is niche?

Answer 8

the position of a species within an ecosystem, describing both the range of conditions necessary for persistence of the species, and its ecological role it plays in a community/ in the ecosystem.
thereby a species’ niche encompasses both the physical and environmental conditions it requires (eg. temp or terrain) and the interactions it has with other species (eg. predation or competition)

Question 9

what does the niche theory predicts?

Answer 9

that with niches distinct from the native flora should coexist with little interaction with native species, yet such invaders often have substantial impacts

Question 10

what is niche conservatism?

Answer 10

Traits that enable species to persist in ecological environments are often maintained over time
- other words: the tendency of lineages to retain their niche-related traits through speciation events and over macroevolutionary time

thereby niche conservatism explains how rapidly niches evolve
- where in climatic tolerances may limit geographic range expansion
- Niche conservatism-based hypotheses can potentially explain many other diversity patterns beyond high tropical richness. For example, some groups actually have higher richness in temperate regions than in tropical regions

Question 11

what are the 3 niche approaches?

Answer 11

grinnellian niche, eltonian niche, hutchinsonian niche

Question 12

what does grinnellian niche emphasizes? according to Grinnell, the ecological niche was defined by what?

Answer 12

emphasizes environmental conditions necessary for a species presence and maintenance of its population

According to Grinnell, the ecological niche was defined by THE PLACE A SPECIES CAN TAKE IN NATURE, determined by its abiotic requirements, food preferences, microhabitat characteristics (e.g., a foliage layer), diurnal and seasonal specialization, or predation avoidance.

Question 13

based on the eltonian nichel, why do some islands have more invasive species?

Answer 13

more invasive species on islands because there are more uninhabited niches

Question 14

eltonian niche approach + explain it with the rhino example.

according to Elton… + ex

Answer 14

approach stresses the functional role of species within the ecosystem

example: white vs black rhino
- white rhino has wider mouthparts, which are excellent for harvesting grass
- black rhino has narrower and more pointed mouthparts, it can feed selectively on the foliage of thorny bushes

According to Elton, each species has a particular role in an ecosystem, and one such role can be fulfilled by different species in different places.
- For example, the observation of ‘distant’ species adapted to equivalent ecological roles (Galapagos finches diversifying to highly specialized roles including those normally taken by woodpeckers). In this understanding, there can be several species that occupy a niche, for example a niche of detritovores, or a niche of specialized tick removers…
This ‘functional niche’ therefore refers to a Species position in food webs, and the concept is thus especially relevant for ecosystem ecology

Question 15

what does the hutchinsonian niche emphasizes? what are the 2 aspects?

according to Hutchinson, the niche is a…

Answer 15

the dynamic position of species within a local community, shaped by species’ BIOTIC AND ABIOTIC REQUIREMENTS AND BY INTERACTION WITH OTHER SPECIES

two aspects:
1. environmental conditions
2. available resources

According to Hutchinson, the niche is a ‘hypervolume’ in multidimensional ecological space, determined by a species’ requirements to reproduce and survive. Each dimension in the niche space represents an environmental variable important for a species persistence. These variables are both abiotic and biotic, and can be represented by physical quantities (temperature, light, soil texture, resource characteristics). Competition modifies the position of species’ niches within the multi- dimensional space. This concept therefore combines the ecological requirements of the species with its functional role in the local community.

Question 16

what are the 2 hutchinsonian niche niches

Answer 16

1. fundamental niche
2. realized niches

Question 17

fundamental niche

Answer 17

it’s a subset of a hutchinsonian niche.

def: the full range of envrionmental conditions and resources an organism can possibly occupy and use, when limiting factors are absent in its habitat

Question 18

realized niche

Answer 18

it’s a subset of a hutchinsonian niche.

def: reduced space due to competition/ predation
- other words: a subset of the abstract fundamental niche, where the species can persist given the presence of other species competing for the same resources

Question 19

what type of niche did Hutchinson extend? how did he extend the type of niche?

Answer 19

Hutchinson extended the Grinnelian niche (the exact descriptions of a species habitat requirements), to include species interactions, HENCE THE NICHE IS DYNAMIC

Question 20

what is the difference between the 3 types of niches? + clarify difference between hutchinsonian and grinnellian niche

Answer 20

1. The Eltonian niche focuses on a species’ ecological role and interactions with other organisms in the community.
2. The Hutchinsonian niche defines a species’ ecological niche in terms of its tolerance to various environmental factors, conceptualizing it as a multidimensional hypervolume
   - *: imagining its ecological preferences and requirements as a space with many dimensions, where each dimension represents a different aspect of its environment.
3. The Grinnellian niche emphasizes a species’ habitat preferences and spatial distribution in relation to environmental factors.

Question 21

explain further the difference between Hutchinsonian and Grinnellian niche

Answer 21

The Hutchinsonian niche builds upon the Grinnellian concept by providing a more detailed and quantitative understanding of a species’ ecological niche. Hutchinsonian niche considers how species interact with each other and their environment, while the Grinnellian perspective mainly focuses on where species live (environmental factors) and what they need to survive (habitat requirements)
- (Grinnellian) like the optimal and tolerance range, but includes a range of factors beyond just that where it emphasizes the physical habitat requirements, such as temperature, humidity, and soil type, necessary for a species to survive and reproduce, whereas the Hutchinsonian perspective broadens this view by considering not only the environmental conditions but also the interactions between species and their ecological roles within the ecosystem

Question 22

explain what the arctic modern transplant experiment target/objective, question, methods, results, and key concept are.

hint: considering the arctic N range has a colder condition than the S which has a warmer range

Answer 22

target/objective:
- wanted to understand if the ability of Arctic plant species to thrive at the warmer edges of their range is mainly limited by temperature or by other factors like interactions with other species

question: Are warm range-margins of arctic sp directly limited by temperature?

methods: They took three plant species from the northern parts of their range and transplanted them to 58 forest sites located at the southern edges of their range.
- Objective: They wanted to see how well these plants would grow and survive in these new, warmer environments over three growing seasons.

Results: as temperatures increased, the performance of these plants also increased, suggesting that temperature plays a role in their ability to survive in warmer areas.
- However, they also observed that these plants weren’t fully utilizing their potential habitat, indicating that other factors might be at play.
- Conclusion: factors like herbivory (being eaten by animals) and shading from leaf litter (fallen leaves) might be more important than temperature alone in determining the success of these plants at the southern edges of their range. This means that interactions with other species and environmental conditions might be limiting their geographic range more than just temperature.

Key concept: manipulate aspects of the transplant to provide insight into the mechanism(s) that do (or do not) limit the geographic range

Question 23

explain the outcome of a transplant experiment in relation to the Grinnellian and Hutchinsonian view where if a transplant experiment fails then there are two possibilities where 1. we rule out the influence of interactions between different species 2. we don’t eliminate the species interactions

Answer 23

1. If we eliminate the possibility of species interactions, and the transplant is unsuccessful then we can conclude we have moved the species outside of its fundamental niche (abiotic factors limit survival and reproduction – “Grinnellian” view focusing on the importance of the physical environment.)
   - simpler: the species couldn’t survive or reproduce because it was placed in an environment that didn’t match its basic needs (like temperature or soil type)
2. If we haven’t ruled out species interactions: it’s possible that the species remains within its fundamental niche, but even if the species is in its ideal environment, it might still struggle because of species interactions (eg. competition or predation) - a “Hutchinsonian” view considering both physical and biological factors in shaping species’ distributions

these views complement each other rather than contradicting each other. Grinnell’s ideas is simply a more restricted take on niches (more focused on the physical aspects of ecology) while whereas the Hutchinsonian view is more integrative (broader approach, considering both physical and biological factors)

Question 24

what are the 2 laws in physiological ecology?

Answer 24

1. Liebig’s Law of the Minimum (Liebig 1840)
2. Shelford’s law of tolerance (1913)

Question 25

Liebig’s Law of the Minimum (Liebig 1840)

Answer 25

if one of the essential plant nutrients is deficient, plant growth will be poor even when all other essential nutrients are abundant

the total yield or biomass of any organism will be determined by the nutrient present in the lowest (minimum) [ ] in relation to the requirements of that organism
- leaky barrel analogy (look at the lowest plank of wood in the barrel = the minimum)

Question 26

what is the famous phosphorus experiment? which topic does this example/case study lie on? which lake was the suspicion of phosphates specifically located at?

Answer 26

Scientists suspected that phosphates were involved in eutrophication, especially in lake Erie

in excess quantities, phosphorus can lead to water quality problems such as eutrophication and harmful algal growth
- (some aquatic resources, such as wetlands, naturally serve as sinks for phosphorus found in sediments or dissolved in water)

When algal blooms die or are eaten by zooplankton, the bacteria that decomposes this organic matter lowers oxygen levels, which can lead to hypoxic water conditions (low [O] that it is detrimental to organisms)

Question 27

side: what is eutrophication?

Answer 27

Harmful algal blooms, dead zones, and fish kills are the results of a process called eutrophication — which occurs when the environment becomes enriched with nutrients, increasing the amount of plant and algae growth to estuaries and coastal waters

Question 28

is Liebig’s law applicable in all situations?

Answer 28

no but it forms a very useful starting point for understanding what limits ecological processes.

Question 29

what is Shelford’s Law of Tolerance (1913)?

Answer 29

all conditions must remain within the tolerance range of an organism. if any condition exceeds this range, the organism will be eliminated

Question 30

1. what are the difference between Leibig and Shelford approach?
2. Shelford was speaking to conditions/resources
3. Leibig was speaking about conditions/resources

Answer 30

Leibig was focused on a single minimum factor that limited growth, whereas Shelford expressed his ideas more generally in terms of a range of factors (minimum and maximum) that organisms can tolerate.

• Shelford was speaking to conditions
• Leibig was speaking about Resources

Question 31

is ‘condition’ a biotic or an abiotic environmental variable? what are the 4 examples of condition?

Answer 31

abiotic which fluctuates in both space and time

examples include temperature, moisture, pH and salinity

Question 32

are resources biotic or abiotic?

Answer 32

may be biotic or abiotic

Question 33

can resources be a condition?

Answer 33

some resources (e.g., water for plants, O2
for animals) can also be a condition

Question 34

The distribution and abundance of a species is controlled by those CONDITIONS or RESOURCES which limit its success. This is similar to the what type of niche?

Answer 34

Grinnellian niche concept

Question 35

how do we assess tolerance? + example

Answer 35

with controlled experiments

example: LC50 (lethal [ ] 50; what is lethal to 50% of the organisms)

Question 36

Typically, we think that it is changes in the environment that affect range expansion, but which case study of ‘adaptation of tolerance on human timescales’ showed that range shifts can occur by adaptation

Answer 36

Agrostis and the Deschampsia (hairgrass)
- Agrostis tenuis has been able to increase its limits of tolerance to heavy metals
- hairgrass has evolved significant tolerance to the contaminants in the soil thereby hairgrass began to recolonize contaminated areas around the Copper Cliff smelter