Communities, Dispersion, Succession, and Stability Flashcards
What is a community
Community is a group of interacting organisms constrained in time and space
What is community ecology
Community Ecology is the study of changes in the community structure over time and the variation between communities throughout space
What are alpha diversities
Alpha diversity studies community diversity within a habitat
What are beta diversity
Beta diversity studies community diversity between habitats
What is gamma diversity
Gamma diversity is the study of large-scale landscape diversity (alpha and beta); it’s a comparison of diversity between ecosystems.
What is the optimal range of tolerance limits
It the optimal environment and the species is abundant
What is the zone of physiological stress in tolerance limits
The species is infrequent
What is the zone of intolerance in tolerance limits
The species is absent
What is the positive interactions for an organism
Positive interactions are something where an organism helps you to grow - you will eventually reach a point where you can’t grow anymore.
What are negative interactions for an organism
Negative interactions are something when an organism will negatively impact the growth rate and will possibly kill off an organism
How do most organisms live with positive and negative interactions
Because most organisms have a mixture of positive and negative interactions there is typically a good area between positive and negative interactions. There is a maximum growth rate somewhere around the intermediate population.
What are competitive exclusion
No two species can occupy the same niche - one will out-compete the other
What is resource partitioning
NIches are divided up by the specialization of competing species.
What are direct impacts
Direct impact of one individual on another when not mediated or transmitted through a third individual. In other words A (donor) influences C (recipient)
What are indirect impacts
Indirect impacts can be defined as the impact of one organism or species on another that is mediated or transmitted by a third. In other words, A (donor) has an effect on B (transmitter) which then affects C (recipient).
What is mutualism
When the two species are benefiting from their relationship
What is commensalism
When one species is benefiting from the relationship, while the other has no impact on the relationship
What is predation
When one species is benefiting from the relationship at the detriment of the other species. This is typically when the larger species is doing the harming
What is herbivory
When one species is benefiting from the relationship at the detriment of the other species. This is typically when a herbivore is benefiting and the herb is not benefiting.
What is parasitism
When one species is benefiting from the relationship at the detriment of the other species. This is typically when the smaller species is doing the harming
What is amensalism
This is when one species has no affect on the relationship and this other is being disadvantaged
What is competition
When both of the species are at a disadvantage
What is neutralism
When both the species have no affect on one another.
What is biogeography
The study of species geographical distribution
How is diversity determined
Diversity is determined by speciation, dispersal, and extinction.
What is the neutral model of community assembly
Community structure is based on historical patterns of distribution and abundance. It is not based on traits, does not consider specific interactions between species, and doesn’t consider niches. The organisms from the same trophic level are interchangeable.
What is the Z-Slope
Quantitative measure of the strength of the relationship between species richness and area. High Z value means richness is highly response to area. This can be caused by genetic bottleneck, speciation, population size is small, genetic redundancy, and carrying capacity. Contiguous habitat is where there are bridges between habitats
What are the conclusions of disperson
Everything seems to be everywhere at lower genetic resolution. The environment selects, but only some factors. Whether is microbial biogeography appears to differ if we are talking about contiguous or island environments.
What are press experiments
Disturbance is maintained constantly and it can be direct and indirect effec.ts
What are pulse experiments
Perturbation is transient and it is direct effect although some indirect effects can occur quickly
What is succession
Succession is the directional and predictable change which a community undergoes over time. These shifts are in the presence and abundance of species. Usually focused on plant species (habitat forming species) but all species are subjected to succession processes.
How is succession determined
The process is driven by the interaction between biotic and abiotic factors. Each species colonizers an environment, it changes the environment to be more suitable to another species.
What is chronosequence
A transition in vegetation that occurs in space and approximates the succession that occur over time in a habitat. These can be used to understand and observe succession over a shorter time span.
What is primary succession
Occurs when a new habitat is colonized. The rate of succession is slower as habitat needs to develop, and niches are formed.
What is secondary succession
Occurs after a disturbance. Disturbance acts to reduce the succession stage of a community and over time succession establishes the new climax community
What is the climax community
It is the end state community from succession. It should be stable and define the habitat.
What are the recent developments in landscape ecology
Ecologists historically observe abiotic and biotic influences on populations over time and space. Spatial heterogeneity was ignored as it’s difficult to observe. Technological fix and statistic methods were developed
What is scale in landscape ecology
Scale is one of the key themes in landscape ecology as it allows questions of population dispersal, and conservation to be addressed
What are corridors and steppingstones in landscape ecology
Useful for tracking the spread of diseases. Agricultural and human pathogens are noted. We have the potential to trace the source. We can infer corridors and steppingstone in spread of diseases.
What are bioindicators
They can be a biological process or community. There is a change in the abundance or activity indicates a change in an environmental parameter. An indicator species will have physiology that is responsive to the environmental variable.
What are microbial indicators.
Microbes are great indicators of biological processes as they do many of them. Microbes have been used as indicator species. Biomarker molecules include diagnostic molecules for the presence of an organism such as fatty acid, DNA, and proteins
During the infant gut microbiome, what are the early colonists
Early colonists are passed directly from the mother during or even before birth, and therefore may lack characteristics that would otherwise facilitate early arrival.
During infant gut microbiome, what happens to bacteria following birth
Following birth, mothers supply bacterial growth factors in breast milk and continue to introduce new taxa through physical contact
During infant gut microbiome, what happens to the maturing infant
The maturing infant is beginning to suppress undesirable taxa through immune response, and actively cultivate commensal taxa by providing nitrogen-rich mucus and favourable habitat in the outer mucus layer of the large intestine.
During infant gut microbiome, what approach did they use
We develop a unique approach to inferring microbial trait data, which entails (1) building a phylogeny that contains the taxa from infant gut samples and 13,900 other taxa with formally described type specimens and Latin binomials, (2) using the Latin binomials to map trait data curated from literature and online repositories onto the tips of the phylogeny, and (3) inferring unknown trait values using hidden state prediction.
During infant gut microbiome, what did trait-based patterns show
The trait-based patterns in our analysis suggest that succession begins with a functionally variable cohort of early arrivers, adept at proliferating rapidly within hosts, which gradually matures into a more functionally uniform cohort of taxa able to both thrive in the anoxic gut environment and disperse between anoxic patches as oxygen-tolerance spores
During infant gut microbiome, how do early and late successional specialists differ
Early and late successional specialists differed significantly in their predicted trait values: late successional specialists were less tolerant of oxygen, were more capable of sporulation, and had higher temperature optima than early successional specialists.
During infant gut microbiome, how do we see the decline of flagella
The initial presence and subsequent decline of taxa likely to have flagella could mean that the ability to actively disperse over short distances improves colonization rates during early succession, but that flagella are not as advantageous in the mature gut.
During infant gut microbiome, what do we know about the sporulating ability
The increase over time in predicted sporulating ability may reflect the long-term advantages of being able to disperse among hosts and/or within hosts in a dormant state during stressful conditions.
During infant gut microbiome, what do we know about correlations among traints
Correlations among traits are noteworthy because they may be independent indicators of a taxon’s position on the same ecological trade-off axis. On the other hand, correlations among traits may simply be artifacts of arbitrary genomic linkage, and not independent instances of evolutionary adaptation
During infant gut microbiome, what do we know about the differences between vaginally delivered and C-section infants.
Notable trait-based difference between the microbiomes in C-section infants, relative to those in vaginally delivered infants, were seen but these differences were not statistically significant after account for multiple comparisons. At minimum, these results suggest that taxa encountered by infants during vaginal delivery are functionally distinct from those encountered by infant after C-section delivery in the hospital environment.
During infant gut microbiome, what do we know about compositional variability
Compositional variability was higher in the first year of development, both in term s of OTUs and predicted traits, than in second or third years of development.
During infant gut microbiome, what do we know about compositional convergence
Compositional convergence across infants over development may reflect a process whereby stochastic cohort of initial taxa colonize infant guts but are gradually replaced, or supplemented with, taxa better suited for the gut environment.
During infant gut microbiome, what does compositional differences across microbiomes tell us
First, it is another reminder that microbial communities with different OTU-based compositions do not necessarily differ in their functional potentials. Second, it means that community succession can be more predictable with respect to traits than OTUs.
During infant gut microbiome, why is functional redundancy important
Functional redundancy among gut microbiome taxa may benefit the host by improving community resilience in response to disturbance.
During infant gut microbiome, why are trait-based approaches important
Trait-based approaches, which link organismal structures to ecological functions, are poised to advance our mechanistic understanding of the gut microbiome, and their usefulness will only increase as we improve our knowledge of how traits mediate microbial interactions and as we increase the depth and breadth of microbial trait databases.
