Week 3 & 4 Flashcards
Plants growing in tropical ecosystems have, on average, much higher N:P ratios than plants growing in high-latitude ecosystems. Why?
Ecosystems in the tropics are older
Feedbacks in disturbance regime and matter & energy cycles
- Linear vs non-linear trends
- Feedback systems keep you in the same ecosystem for a long time
» If you have strong feedbacks, you don’t see any change in a community until it suddenly changes to an alternative stable change
» The more resistant communities have a high feedback loop and that causes unpredictability (it looks like nothing is happening and then there’s a sudden big change)
Alternative stable states
- It occurs when in the exact same environmental conditions there are two completely different ecosystems
» E.g., the soil is the same, climate is the same, but you can find different ecosystems like grasslands and forests - There is a positive feedback loop going on in each of the states
- Because the different states have feedback loops going on they can co-exist next to each other (e.g., grasslands and forests coexisting)
True or False: SE-AS framework was developed in response to the following critique of the SES framework in the study of social-ecological systems. “The SES framework requires a more explicit incorporation of ecological attributes”
True
(explaination: One of the main contributions of the SE-AS framework is its further unpacking of the interactions within an action situation. Rather than purely social interaction (i.e. the S-AS), they include other types of interactions between human and non-human entities. In this way, it draws focus to these ecological attributes in the study of SES)
True or False:
During succession the vegetation biomass generally decreases.
False
What is the redfield ratio?
- He traveled all across the ocean and took samples everywhere from the phytoplankton
- Compared C : N : P ratio and found that they are all the same: most of these phytoplankton have 106:16:1 (106 carbon relative to 16 nitrogen relative to 1 phosphorus)
- The N : P ratio is similar to the ideal, which signifies that there is some kind of rule that plants need about 16 times nitrogen relative to phosphorus (for optimal growth)
During succession, when do we see higher amounts of nitrogen? Phosphorus? Why?
- At the beginning of a succession there is a lot of phosphorus, which is also mainly found in the ground/soil
- Nitrogen on the other hand comes from the air and has to be fixated by the plants in order to use it (fixation takes time and then builds up in the system)
- In late successional stages there is usually more nitrogen than early successional stages
The relationship between species richness and ecosystem functioning generally follows the shape of which hypothesis?
Redundant hypothesis
The study of SES requires focusing on two key subsystems - the social and ecological subsystem. Their relationship is characterized by 2 features–what are they?
Coupled subsystems & interacting subsystems
Which process can be reduced by large herbivores? Why?
Competitive exclusion; when herbivores eat certain plant species, there is less competition amongst them
True or false:
Silvia & McGuire’s study shows that task-oriented leadership is more important in collaborations, compared to single organizational settings
False
True or false:
Silvia & McGuire’s main argument that leadership in collaborations is different, is that within networks there is not one hierarchical ‘boss’ who can give orders or fire other stakeholders.
True
Which of the following elements does not have a gaseous phase? Carbon, nitrogen, hydrogen, phosphorus
Phosphorus
What are some things we can assume about this graph?
- Fragmentation reduces biodiversity by up to 75%
- the effects of fragmentation are greatest in smallest and most isolated fragments
reduced areas - species area relationship (SAR)
SAR = the relationship between the area of a habitat, or part of a habitat, and the number of species found within that area
- The smaller the area you have, the less species richness there is
Limiting factors
- habitat heterogeneity
- speciation
- fragmentation
- dispersal
True or false:
SAR refers to the relationship between the number of species and the size of the land.
True
What is habitat heterogeneity
It is one of the factors that can impact SAR and is the variation of physical characteristics of a specific habitat, including weather, vegetation, and soil
What are some of the important variables in regard to increased isolation/fragmentation?
- size of the fragments
- distance between the fragments
- proportion of edge habitat
Explain the relationship between habitat fragment size and the edge effects, as shown in the image
as fragment size increases the relative proportion of edge habitat decreases, and interior habitat increases
Explain meta-populations (in regard to habitat frag)
A meta population is a “Population of populations” (Levins, 1967) on a patchwork of “suitable” habitat within a non-suitable matrix, interconnected by limited dispersal.
What are some of the characteristics of meta-population?
- Frequent local extinctions
- Long-term survival of the
metapopulation is dependent on
colonization through local
dispersal.
In terms of habitat fragmentation, what do we mean by connectivity?
- Distance from all the other occupied patches
- Area/Size of those occupied patches
- Dispersal distance of any given species (i.e. dandelion seeds vs. stone fruits)
Source vs sink (in regard to meta-populations)
→ Source: subpopulations with positive growth rates; they act as sources (individuals disperse from there to other subpopulations, including the sink subpopulations)
→ Sink: subpopulations with negative
growth rates (in absence of dispersal)
What is meant by island biogeography in regard to habitat fragmentation?
The distribution of species on islands could be interpreted as a balance between the opposing forces of extinction and colonization (from the mainland)
Island biogeography: what are the two main variables that determine colonization and extinction rates
- Distance from mainland
- Island area
What is matrix quality?
Matrix quality refers to how well urban areas support biodiversity in between the patches and corridors. Areas with more street trees, bioretention areas, green roofs, and backyard gardens are better able to support native plants and animals.
How would the change in matrix quality affect migration rate?
Matrix quality refers to how well urban areas support biodiversity in between the patches and corridors. Areas with more street trees, bioretention areas, green roofs, and backyard gardens are better able to support native plants and animals.
What are some characteristics about matrix quality?
- The matrix type is important, but is species-specific
- Patch size (area) & isolation (connectivity) effects were stronger
- Matrix quality increases with increasing structural similarity with habitat patches
- Management: create a matrix as similar as possible to the habitats within the fragments
What is ecosystem functioning?
Reflects the collective activities of organisms (plants, animals, microbes etc.) and the effects these activities (e.g., feeding, growing, moving, excreting waste) have on the physical and chemical conditions of their environment.
What are ecosystem services and what are the four types?
Ecosystem services are ecosystem functions that provide goods and services that satisfy human needs, either directly or indirectly.
1) Provisioning - resources, extracts
2) Regulating - maintain something
3) Cultural
4) Supporting
Primary vs secondary succession
- primary: bare rock, no soil left (building from the ground up)
- secondary: no vegetation is left but there is still soil
What are pioneer organisms in regard to ecological succession?
They come into an area and help to build it back up. For example, lodgepole pine, lupin, etc
What are some things that typically happen during succession?
- Productivity tends to go up (i.e. at later stages you have much taller tree species)
- Env. filtering at the beginning is high because hardly anything can survive, but at the end you get competitve exlcusion because of how many species now exist there
What are things that can move back ecological succession?
Fires, overgrazing
What is stoichiometry?
Links between biogeochemical cycles
i.e. how much nitrogen in relation to phosphorus do we have
What do these elements provide?
1) Carbon
2) Nitrogen
3) Phosphorus
1) C = Structure (cell walls), energy (sugar, starch, fat)
2) N = protein -> enzymes
3) P = DNA, RNA structure (bones, exoskeletons)
Why do terrestial plants need/have more carbon than aquatic plants?
For structure
What are some observations about this?
In areas where it’s dry or cold, you find nitrogen limitations. Whereas in warmer/wetter areas there is a phosphorous limitation. Because of rain, the phosphorous gets washed out (it’s a soil based element).
Succession and N:P limitations
At the start, there is little nitrogen–it builds up throughout time.
You start with a lot phosphorus in the beginning but through time it goes down.
What are trophic interactions?
They are important structuring mechanisms of ecosystems, e.g. between plants and herbivores or between predators and prey.
- they partly determine the energy flow through a system
- also determine stocks (the energy stocks through the system)
What is “land sparing” and “land sharing”?
→ Land Sharing: A situation where low-yield farming enables biodiversity to be maintained within the agricultural landscape.
→ Land Sparing: Where high-yielding agriculture is practiced, requiring a smaller area of land to attain the same yields and therefore leaving greater areas of natural habitat untouched.
Leadership definition
“The process of influencing others to understand and agree about what needs to be done and how to do it, and the process of facilitating individual and collective efforts to accomplish shared objectives.”
Transformational leadership
▪ Transforming the values of employees from the individual to the organizational level
▪ Sharing a vision, individual attention, intellectual stimulation, being a role model
▪ example = Leslie Knope
Transactional leadership
▪ Motivating employees by using rewards and punishments
▪ ‘Carrot & stick’ approch
▪ example = Ron Swanson
How can transformational leadership drive change? (what are the dimensions of it)
- Individualized consideration (i.e. giving individual attention to specific people within an org)
- Intellectural stimulation (i.e. help ppl think along with you)
- Idealized influence (i.e. leading by example)
- Inspirational motivation (i.e. giving employees a vision for the future)
Collaborative leadership
- seen as a critical ingredient for bringing parties to the table and steering them towards collaborative processes
- focuses on mutual influence among members of a less hierarchial, more egalitarian team
Collaborative leadership in a network
▪ Combining strong and weak ties
▪ Open processes: including different types of expertise
Biodiversity and ecosystem functioning (BEF) - What is the difference between rivet and redundant hypothesis?
→ Rivet = the more species you get, the higher their function
→ Redunant = if species richness increases, at first yes, your function increases but over time it tapers (adding more species doesn’t have much of an effect)
True or false:
Biodiversity increases ecosystem functioning
True.
The graph on the right: with more species, there is less nitrogen in the soil, so productivity is higher
- niche partitioning also increases BD
Another example:
- If you have two earthworms, then they have the same function
- However, if you have an earth worm and a different kind of worm you still have two decomposers, but they could also have very different ecosystem functions => it is more “useful”
» So, functional diversity seems to be more important than species richness in general
» And it is also especially beneficial to have more species if they are different from each other (because they might have a different niche but also offer different “services”)
» Functional diversity is defined through the traits of the organisms (=> traits are morphological or physiological attributes of an organism that can be measured on an individual, e.g. plant height, animal body size etc.)
Functions vs species richness
- usually has a positive effect on the function of ecosystems. one reason being niche partitioning.
- it’s not always positive however, but why? look @ functions–if there are too many similar functions, it doesn’t help BD
- losing species doesn’t necessarily effect the ecosystem functions
BD - Disturbance (i.e. hurricanes, flood, drought, etc)
- resistance = determines the extent to which ecological processes (and provisioning services linked to those) remain the same @ various external pressures. the less it dips, the higher the resistance. it also increases with BD.
- recovery = determining the rate @ which an ecosystem returns to its previous state after a disturbance; rate of recovery
BD - Gradual change (i.e. temperature increase, CO2 concentration, human pop. growth, etc)
- we see that recoverable species have a lot of changes because they aren’t resistant, whereas w/resistant species there won’t be change until a tipping point
- at an individual level, one could have similar dna but grow up in a diff env, thus looks different
- species level adaptation: animals change their behavior based on if there are lions, for example (i.e. if there are lions present during the day, the animals would be active at night)
- species level evolution: peppered moth example
- community level: species replacement
- ecosystem level: you don’t see change until a sudden big change, leading to an alt. stage state
Organisms face changes in their environments. Name three process through which species (or individuals within species) can cope with such changes in the environment.
- Plasticity
- Behavioral adaptation
- Natural selection
Trophic effects on BD: trophic cascades
- removing a higher trophic level has cascades
- estes looked at trophic cascades by otters: found that places where otters had gone away, sea urchin pop went up
What are social-ecological systems? (SES)
- Social subsystem – individual and collective human needs
- Ecological subsystem – healthy habitats and ecosystems functions
- SES contains and comprises of the two above subsystems. They both interact and produce system outcomes.
Usefulness of SES approaches
- Holistic approach to examining BD issues
- Focuses on feedback between the two systems above
- Examines the emerging outcomes processes that occur at a system level
- Humans are fundamentally dependent on ecosystem services, but are also a major force in shaping ecosystem dynamics in strategies in fulfilling human needs
Similarities between wicked problems and SES
- Scale sensitivity
- Cross-scale interactions
- Non-linear interactions
- Uncertainty
- Path-dependency—legacy of the past
- SES = Resilience based approach to managing wicked problems through adaptive governance
Poor social considerations in conservation planning
- socio-economic factors (enable and constrain implementation
- How outside agendas conflict with local needs
- Socio-ecological trade-offs from conservation actions
- SES approach could give a better understanding of human interactions, benefiting both ecosystems and human communities
Research on SES
The difference lies between how they view the relationships between the ecological and socio subsystems
→ Loose: For example, human actions as the drivers for ecosystem dynamics
→ Tight: thru mind, experience, or place. They are explored as the roles of humans as co-produced ecosystem system. That see social and ecological relations.
SES framework
Shows that the SES is made up of interconnected subsystems
- Resource system: forests, coastal areas
- Resource units: fish, trees
- Governance system: Management of forest, or coastal area (i.e. management of intuitions)
- Actor/users: loggers, hikers, fishers, basically whoever uses the resource or whose activities affect the systems
Unpacking the SES framework & critiques of it
- There are tons of diff attributes
- Can be used to describe the SES
- Enables the analysis of different ecological issues and can be used to see what’s been the most effective to tackling those. This allows us to reach conclusions about design features needed to address specific elements
- The elements to different subsystems can further show how you can unpack things
- critiques: insufficient consideration of
ecological attributes & poorly understood interactions & outcomes
Example of SES approach to conservation planning
- To explore interactions and outcomes with more detail
- Cultural links between people and environment
- Traditional fishing practices
- SES approach could improve conservation planning
- By integrating the SES approach in conservation planning, we can compare conservation plans in different contexts and make some general conclusions about what’s working and what isn’t
- Integrating an SES framework also makes conservation planning more dynamic as feedback loops are introduced
- Using this combined approach in combination with other participatory approaches (i.e., mapping with stakeholders, having focus group discussions etc.) we can obtain actors’ values of different stakeholders, which can be directed towards conservation 🡪 this can help to find appropriate conservation options
SE-AS Framework
- Explore interactions & outcomes in more detail - Zoom in to the action situation part of SES
- Key to understanding SES
- Treat human actors & ecological entities as ontological equals
- Responses to changes in SES
- Expand on AS—from purely social action/interaction to other types of interactions
» SE-AS reflects actions between human and non-human entities. For example, cultivating, harvesting, converting, ecological monitoring, polluting
Nature adapts: bird vagrants
- Adapting to human driven alterations (to earths water, land, and/or skies)
- Doesn’t happen by accident, vagrancy could help certain species find an escape route for climate change
What is resilience?
- Has been applied to ecological systems
- The capacity of a system to absorb disturbance while undergoing change to retain the same function, structure, feedbacks
- This graph is used to depict the concept (ball & cup diagram) of eco-resilience—an ecosystem (the ball) remains w/in a set of bounding conditions, represents resilience state bc when disturbed the recovery trajectory are convergent to the bottom of the cup by gravitational analogies. Disturbances like fires, for example, can force the ball to move across a threshold, into a different resilient state.
Example of SES responding to change
Climate change can affect ecosystems in which ppl depend on for their livelihood. These people can respond by adapting land management to adapt the ecological system itself.
Theoretical resilience framework
- Adaptability is the ability to maintain certain processes despite the changing internal demands or external forces that are acting on those systems
- Transformability is the capacity to create a fundamentally new system when the existing one becomes unbearable
Adaptive governance
- Interactions between actors, networks, organizations, and institutions for the pursuit of a desired state for SES in the face of uncertainty and change
» Build resilience of the existing SES
» Facilitate the transformation to an alternative state of SES function
What are the enabling factors necessary for successfully transitioning existing governance towards more adaptive governance?
- Knowledge generation, learning, and social memory
- Participation, collaboration & stakeholder dialogue, formation of actor groups or teams
- Devolution of management, rights or power sharing (decentralization)
- Organizational flexibility, trust, leadership
- In all 3 cases, the shift towards adaptive governance was motivated by an awakening crisis that had affected the ecosystem services and had biodiversity consequences
Case study: adaptive planning in Australia
- Conservation measures—mixed results & poor long-term performance. National and state government are involved in conservation policy making.
- Gap: expand focus beyond protected areas & already endangered species
- Improve conservation policies, to make them better suited to the long-term CC effects. To do this, they did used the adaptation pathway approach.
- Route A: focus on proactive future change / uncertainty
→ Focused on the short-term
→ What they expect from policymaking is that climate change is more considered and discussed with regard to conservation efforts - Route B: expand the focus of conservation laws and policies to the landscape-scale protection
- Route C: would apply reforms both to the scope as well as creating a more adaptive approach simultaneously
→ Focus on two levels:
1) Approach used (more adaptive and long-term focused), thinking about uncertainty and climate change
2) Reform policies to be more extensive
Adaptation pathways and examples
Adaptation pathways is a planning approach addressing the uncertainty and challenges in SES decision-making
- I.E., climate change, delta planning, BD conservation
Considers multiple possible futures, and allows analysis/exploration of the robustness and flexibility of various options across those multiple futures
What are the steps in designing adaptation pathways?
Whole idea is to adapt to certain pathways, give people flexibility in the way they navigate the systems and respond to them over time. It’s easy to switch to a different pathway that would be more advantageous to a certain situation.
1) Baseline situation: what is the current state/policy, it represents what is currently happening in the system at that point in time
2) Future scenarios map: e.g., in 100 years, what will this particular system look like?
» This step gets a variety of potential scenarios, and you also want to identify what people value when thinking about the future
3) Formulate pathway: a sequence of actions to get you the current state to future scenarios
» You can formulate pathways in 2 ways:
- Forecasting method: moving from the present context to the future scenario
- Backcasting method: working backwards from the future back to what is needed
» Depending on the future you want to see, you work backwards all of the actions that are needed to then see that outcome in the future
4) Tipping points: they tell us at what point a certain pathway is no longer useful and effective, and then we need to formulate a new one (e.g., shifting from action/pathway A to B to C…)
