Week 1 Competition Ecological organization:
Competition for: finite amount of Resources + Space ▪ Individual: one member of one species
Competition is a negative two-way interaction -> there is always a loser. ▪ Species: a group of organisms that can successfully interbreed and produce fertile
Intraspecific competition: competition between individuals of the same species. offspring
Interspecific competition: competition between individuals of different species. ▪ Population: multiple members of the same species in the same location that interact
Competition for resource: if one takes the resources there’s fewer left for others. with each other
Competition for space: If you take out a space for your resources, the competition ▪ Community: multiple populations of different species in the same location that can
for the other spaces becomes more intense because there’s less space left. Very interact with each other (only biotic factors)
much like nature conservation, if you plan a space for nature conservation you can’t ▪ Ecosystem: all of the biotic and abiotic factors combined in one location
use it for other things -> more competition. ▪ Biome: ecosystems that broadly share some baseline abiotic characteristics and occur
in the same region of the globe
Intraspecific competition in human populations ▪ Biosphere:
Example the full competition
intraspecific set of abiotic and biotic conditions in the Example
world interspecific competition Gause’s law:
If we have a pool of shared common resources, each individuals’ own needs will cause them to want to occupy more of the Resources: nitrogen, phosphorus, water, sunlight No complete competitors -> one may be better able to compete complete
spaces to get the resources they need. People don’t face the consequences of overusing resources, because the Complete competition: two individuals competing for for sunlight, the other one for water competitors
consequences are shared across everyone. Freedom in a commons brings ruin to all.The tragedy of the commons: the the same resources in the exact same way/tactics, maybe they can coexist, because they’re not complete cannot coexist, of
population problem has no technical solution; it requires a fundamental extension in morality (garett hardin) (extended mostly individuals from the same species (same niche competitors. If intraspecific competition > interspecific one individual is
version of Gause’s Law).People with more resources initially will have more power, with that power they can gain even more and tactics/genes etc) competition = then there can be coexistence between different only slightly
resources quicker. Environmental racism, more pollution factories etc in poorer areas because they can’t fight the richer complete niche overlap (niche: combination of abiotic species a member of your own species will compete harder with better,
institutions. Garrett hardin was a hardcore white nationalist, wanted to use this idea to promote population control, but he factors an organism can live in) you than a member of a different species, so each species is the other one will
only wanted to use population control in certain demographics (bad guy obv) more self-limiting than limiting the other species be outcompeted.
Week 2 Facilitation Bottom-up management is the best for ecological resources
Garrett hardin: the population problem has no technical solution; it requires a fundamental extension in Gause’s law: complete competitors cannot exist
morality. Elinor Ostrom: questioned assumptions of tragedy of commons (strong assumptions). Facilitation: cooperation in plant communities
Cooperation can change the dynamics of a commons’ situation. Assumption: most logical thing is for Only focus on how plants avoid being complete competitors, not on how plants can
everyone to act in their own self interest (economically), everyone should try to maximize their economic cooperate (facilitation)
profit/benefit of the commons Similar in own model: individuals are always going to compete to the Increase in stress -> more facilitation
greatest extent possible. Competition coefficient has a negative effect on our population Is false. Ostrom Diversity ameliorates stress/improves the microclimate
made 8 design principles for managing the commons, by changing the assumptions Based on cooperation (Jena experiment diversity and flooding, biodiversity patches were less negatively
(positive interaction).In members of an ecological space: cooperation is facilitation (positive interaction) affected by the flood than monoculture patches -> facilitation of different species,
diverse communities could return the soil to the original structure)
▪ Facilitation can
Two types of restoration Nutrient poor sand soils (hard to colonize). Unstable, few nutrients -> small grassplants - ▪ Enable coexistence
expected at Vliegbasis colonize there first. produce plant litter. Decomposition of plant litter ▪ Increase ecosystem functioning (facilitation increases productivity)
Soesterberg: Active Allows plants with higher nutrient needs to be able to colonize there as well ▪ Increase germination rates (seedlings can establish in the soil better)
restoration (going in and = facilitation. Small plants also stabilize the soil (holding soil together) -> makes it easier for ▪ Important for restoration
planting and whatever) other plants to settle = nurse plant effect: little area around an existing plant is more stable
Passive restoration (just to colonize.Small plants make the area a cooler and nicer micro climate with less stress
letting it be) The area is (sand can get very hot and sunny)
really large, so they
choose passive
restoration. Passive
Facilitiation is important at these types of sites (old military site), because there’s
restoration relies heavily
widespread soil degradation
on facilitation (current
Tanks/contructions are pressing down the soil/decreasing soil porosity, so plant diversity is
plants need to facilitate
necessary for opening up the soil structure/create macropores to facilitate further diversity
for new plants)
Lots of secondary succession at Soesterberg
Three stages: Grasses through cracks in the asphalt, shrubs growing on structures, trees
growing on structures
Plant biodiversity scales to all of the other levels in the food web as
Mechanisms for positive biodiversity Biodiversity is declining worldwide. Experimentally
well:
effects: manipulating biodiversity and see what happens to the
▪ Greater abundance and diversity of pollinators
▪ Biotic feedbacks environment and extinction
▪ Greater abundance and diversity of soil
▪ Resource partitioning Conclusions:
decomposers and herbivores
▪ Abiotic facilitation High biodiversity -> high primary productivity
▪ More complex soil structure
Higher biodiversity -> ecosystem functions
▪ Less negative effects from pests and pathogens
▪ Pollinator diversity and abundence
▪ Greater diversity of aboveground herbivores
▪ Soil food webs
▪ Greater carbon storage – which means less carbon
▪ Soil structure
that would otherwise be in the atmosphere and
▪ Dilution effect of pathogens
contributing to climate change
Small germinants: ▪ Biodiversity and carbon cycle
Less NSC (non-structural
carbohydrates = Higher biodiversity -> buffers temperature changes, higher surface level soil moisture, lower air temperature, increase in Abiotic facilitation and the microclimate:
emergency resources) relative humidity, vapor pressure deficit decreases (VPD). Microclimate amelioration is stronger on hotter/drier days. ▪ Plants cast shade on the microclimate around them ->
Less root depth/surface Collated: different physiological strategies, stem types etc have a different effect than just increased biomass. Stress reduces the temperature
area Gradient Hypothesis: Plants benefit each other (facilitation) when they coexist in stressful environments. Plants compete ▪ Plants evapotranspire and this humidifies the
More sensitive intensely with each other when they coexist in mild environments microclimate
Larger germinants: Hypo 1: microclimate amelioration in higher diversity plots benefits plants when it is hot & dry, but not when cool & ▪ Plants block the drying effects of wind, trap air and
More root surface humid (VPD effect) -> more facilitation. Plant water stress is higher with high VPD. Mild/cool conditions and high create boundary layer microclimates
area/depth biodiversity plot: there’s more stress for water -> higher competition for water, because of different strategies due to ▪ The microclimate effects of one plant can affect the
biodiversity Hot/dry conditions and high biodiversity plot: positive/facilitative effects of diversity on plant water -> performance of its neighbours
More redundant carbs More biomass means more shade and
microclimate is a lot cooler and more humid, because of protected microclimate ▪ Biodiversity -> microclimate -> coexistence ->
Absolute quantity of lower temperatures
Hypo 2: the most vulnerable individuals will be most positively affected by microclimate amelioration ecosystem functioning
resources needed More biomass + more water use
increases (more limited strategies means higher humidity and
by competition) more temporal coverage of microclimate Facilitation remains equal for all sizes and Checking the underlying mechanisms for
Competition can limit humidity biodiversity, but competition increases with facilitation and competition
growth of individuals More canopy complexity means greater size and biodiversity Adding the limiting resource to see the effect on
Small germinants aren’t wind interruption and stronger boundary Competition has a negative effect that is equal competition -> competition is not size dependent,
affected by biodiversity layer effects for all sizes but increases with diversity, but all sizes benefit equally from added resource
Medium and large Higher biodiversity creates an emergent facilitation has an effect as well but it increases Facilitation via microclimate amelioration
germinants are microclimate that improves performance with diversity and decreases with size decreases with plant size, so smallest individuals
negatively affected by of constituent species and overall benefit the most
biodiversity ecosystem functioning
Decomposition: organic matter is made smaller into smaller
Week 3 molecules until they have become inorganic matter
All ecosystems have one thing in Leaching: soluble compounds are carried away by water.
common: organisms in it, that later Fragmentation: physical or chemical reduction of OM into
turn into organic matter smaller particles. Mineralization: production of inorganic
(OM).Organic matter: relating to or end product. Organic soils: > 30% organic matter. Peatland:
derived from living matter (OM) >70% organic matter
Peatland: an accumulation of partially decayed plant
materials due to waterlogged conditions, lack of nutrients
and it’s acidic, often overstrooomd → weinig microbial
Scavenger Types of peatland formation:
activity -> weinig gedecomposeerd OM
Detritivores Bog: rainfall controls the waterlevel, acidic,
Saprotrop relatively nutrient poor
Veen: groundwater controls the What determines the speed of decomposition? pH,
hs
waterlevel, less acidic temperature, type of organic matter (lignin, cellulose,
glucose), water content, oxygen availability, Litter quality:
type and quantity of carbon compounds
Abiotic factor: oxygen. needed for respiration by microbes. not much oxygen in simple sugars: easy to break, hemicellulose, celluslose and
peatlands -> microbes use other compounds for respiration. sulfur is used, but provides lignin → enzym
Effects of grazers: Undisturbed peatlands: low N and P ->
less energy (less good electron acceptor). seasonality causes drier periods zones in
Increasing/decreasing species present: microorganisms need N and P from OM ->
peatlands. aerated: oxygen/air can enter. temporary water-saturated (water level
Increasing/decreasing colonization (biopertubation, spread of produce enzymes to make it available
varies, some seasons oxygen can enter this layer). water-saturated (mainly anoxic NL is small, but has a quite high amount of peatland
seeds etc) Agricultural peatlands + fertilizer: no need to microorganisms choose in which layer they live depending on oxygen and water and (Randstad en friesland)
Increasing/decreasing local extinction (preferred food, trampling produce enzymes -> high N and P -> become
their tolerance. aerob/facultative/anaerob microorganisms Peat is rich in OM -> energy source
plants etc) less active aerated zone with aerob microorganisms: decrease water level -> o2 available -> co2 Peat for agriculture, infrastructure, natural area
Multidiversity: the diversity of multiple species
emission increases -> more decomposition. water saturated zone with anaerobic Peat used to be an energy source -> where taken away is
Removing grazers form an area positively influences soil
k-strategy: slow-growing microorganisms: higher water level -> less/no o2 available -> ch4 emission increases -> now usually polders
macrofauna
r-strategy: fast-growing, reach carrying capacity more anaerobic decomposition. Methane is product of anoxic respiration. co2 is Water level/table is decreasing -> oxygen available for MO ->
Changing competition, facilitation, environment dynamics
really fast product of respiration with oxygen. closer to water -> more methane producing decomposition -> more CO2 emissions -> land subsidence
For example by poop -> increase in N -> increase in plant species
High nutrient availability: stoichiometric theory microorganisms
extinction -> change dynamics between diversity and productivity
-> bias in creating biomass -> no more competition for N but for Low nutrient availability: nitrogen mining
theory abiotic factor: OM type
light -> more biomass catches more light Iron-gate theory: recalcitrant organic compounds -> easily degradable organic
Grazers are very closely managed Reduction of water table, oxygen available, iron 2 will be converted to iron 3 and this compounds
Also difference in how hard it is to manage certain grazers (deer decreases pH and then phenolic oxidase can’t be active, so phenolic compounds won’t
Week 4 Meta-population theory r-strategists win the competition in easily degradable
and geese are harder than cows) be broken down and exoenzymes can’t decompose peat
Metapopulation: population of sub- organic compounds, because they can degrade it faster than
populations (there is connection/dispersal 2 drivers of meta-population dynamics: Protects peat soil organic matter
between the populations, connected by Population size: bigger population has abiotic factor: nitrogen and carbon= energy source
direct and indirect connections, genetic more control over the metapopulation metabolism: enzyme production -> DNA and RNA necessary
dynamics by leaving individuals Nitrogen mining theory
exchange) Carbon and nitrogen are necessary for DNA and RNA
‘infiltrating’ other populations Low N availability can increase litter
Metacommunities: community of sub- then it’s easily accessible for them. If N is below the
Connectivity: isolated population receives decomposition as microbes use labile
communities threshold, the N mining theory can be applied -> k-
least genetic variation, could also be good substrates to acquire N from
Functions of metapopulations: strategists advantage, are more active producing enzymes
because it continues to adapt to the local recalcitrant organic matter = if there’s
Examples: More resilient to local extinction -> more and degrading more recalcitrant OM.
environment very quickly, however with no N, the microbes will become more
Park source or forest source genetic input Soil organic matter is hard to degrade
local extinction population is hard to active to get N
Quarantine = cutting off Receiving genetic material from not Fresh residue organic matter is easy to degrade
rescue Either theory is possible for different
connectivity of 1 population adapted individuals when you’re in a very Theories how C and N availability affects the microbial
Source/sink: big population is usually a microbial strategies
Travel regulations = cutting specific environment is not really beneficial composition: Stoichiometric decomposition theory
source, small population is usually a sink When N comes above a certain
off connectivity of Repopulation after (almost) local extinction The microbial activity is highest, and decomposition rates
threshold then the CN ratio becomes
populations on a larger scale of one population -> rescue are maximal, if C and N input with substrate matches
Vaccines: regulating important (stoichiometric) -> r microbial demands, that is, when this input corresponds to
population size of infected strategists need CN to be in a ratio if C stoichiometric C and N ratios
individuals is not limiting.