ecology pt 2. bio quiz

Niches: a species’ job

* Role and position of a species in its environment, including interactions with biotic and abiotic factors


* Fundamental niches: full range of conditions and resources under which species can survive and reproduce
* Realized niches: actual conditions and resources in which a species exists due to biotic interactions and constraints 

Fundamental Niches (theoretical)

* Fundamental niches are determined by abiotic factors, such as temperature, precipitation, and soil type


* Ex. The niche of a polar bear is any arctic region where it can hunt seals on sea ice and hibernate in winter 
* Fundamental niche can be represented by what environmental factors a species requires. 

Realized niches (actual)

* Realized niches are influenced by biotic interactions, such as competition, predation, and mutualism, as well as abiotic factors


* Ex. The realized niche of a polar bear is smaller than its fundamental niche because it faces competition with other predators and food scarcity during the summer months. 
* The realized niche is the overlap between the fundamental niche and the actual conditions in which a species lives. 

Niche Overlap

* when two or more species use the same resources in the same habitat (food water shelter)


* Leads to competition
* When northern Canada gets super cold winter storms polar bears venture toward Canada. They compete with local grizzly bears. 
* Polar bears are actually TERRIFYING 

Niche Partitioning

* the process of dividing up resources in order to reduce competition between species


* Occurs through spatial/temporal separation or using different parts of the same resource
* Usually from species evolving to coexist
* Birds may coexist by feeding on different insects in different parts of the canopy

Niche specialization

* Niche specialization: adaptation of a species to a spesific set of resources or conditions


* This can increase the fitness of a species in its environment, but  also makes it vulnerable to changes in those conditions
* For example, the panda’s specialized diet diet of bamboo leaves it vulnerable to habitat destruction and climate change.

Ecological Succession

* Ecological succession is the gradual change in species composition and community structure over time in a given area (how a community changes over time)


* Often due to wildfires/landslides or other disasters


* Leads to changes in ecological niches as the environment changes
* Can also refer to the colonization of an area
* Think in terms of NATURE

Pioneer species

* Hardy species that are the first to colonize an environment that may have been disrupted


* characterized by their ability to tolerate harsh conditions (ex. Extreme temp)
* Can be plants, mosses, animals, etc. 
* Pioneer species help prepare the habitat for the establishment of more complex communities by breaking down rocks and soils for increasing nutrient availability

Intermediate species

* The next group of the organisms to establish themselves in the ecosystem after the pioneer species


* More diverse
* Plants that can stand (Bushes!)
* Animals start- birds and insects
* Prepares the dirt in increasing nutrient availability for later plants

CLIMAX COMMUNITY

* Final stage of the development and ecological succession is over


* Takes a while to get to this point
* Everything is balanced 
* Dependent on the local climate, topography, and soil conditions
* Large, tall trees
* Stable and self sustaining ecosystem with little change

Population Density 

* Population density number of individuals of a species per unit are or volume
* Population size within in an area
* Affected by how many resources are available particularly food and shelter
* A function of 
* Birth and death rate
* Immigration and Emigration
* Resource availability
* Carrying capacity: max pop supported by environment

Population Distribution 

* Pattern of spacing among individuals of a species within a specific area


* Many patterns exist some are
* Random distribution: Spacing in between individuals us unpredictable due to nature pushing individuals around 🌱
* Clumped distribution: grouped in patches or clips, usually gripes in a herd around a resource 🐃🐑
* Uniform distribution: Territorial animals spreading evenly around an area/resource 🐅 🦆

Habitat range:

* Refers to the physical location and conditions where a species can be found and reproduce in nature


* Can be narrow or broad, depending on the species’ ability to adapt to different environmental conditions

Tolerance range:

* The range of environmental conditions that a species can tolerate without experiencing physiological stress or death


* Environmental conditions within which a species can survive. 

Competition for resources:

* Competition occurs when two or more organisms are competing for the same limited resource


* Competitions has a negative effect on both members 
* Both may become injured
* Resources reduces in a competition situation verses when there is no competition
* Limits population numbers

Intraspecific competition

* More intense
* Harmful
* Fighting for same resource
* Limits pop size
* Some develop strategies
* Territory are established
* Social hierarchy

Scramble competition

Scramble to get resources at the same time

Contest competition

* Resources are used by only one or few individuals (winner) (winner take all)


* Opposite of a scramble competition

Social competition

* Available resources are split according to a social hierarchy
* Dominant individuals have priority access
* Lower ranked individuals contest what remains

Interspecific competition (google it…)

* Interspecies competition: different species competing for same limited resource
* Interfering directly with the ability of others to gain access to the resource
* Exploiting the resource before others can access it
*  Less destructive than intraspecific: different species have different requirements 
* Each species usually has an alternate resource it can use to reduce competition

Reducing competition between species

* Competition is harmful so species have adapted to reduce competition 


* Species that need similar resources have behavioral adaptations to reduce competition
* Each species uses a small part of the all available resources to avoid competition EX:
* Different locations: different monkey species might live in different heights of the tree
* Different times of day: one bird might feed at morning, one might feed in the evening
* Different diet: different birds in the same tree might look for different types of food like bugs vs. berries

Predator Prey Relationships

* How is each regulated?


* Prey is often more regulated by resource availability and climate rather than predators 
* Predators are the same except their (food) resources are prey. This means that prey regulate predator populations
* Predator populations are affected by the availability of prey
* Results in a delayed oscillation: predator numbers follow prey numbers with a time lag  (oscillations are when something moves in a wave like pattern)

Carrying Capacity

* Carrying capacity :the maximum number of individuals of a species that can be supported by a given environment over a sustained period of time. 


* The maximum population size that a particular habitat or ecosystem can sustain without depleting its resources beyond their capacity to recover.
* Determined by its most limiting factor
* Carrying capacity :the maximum number of individuals of a species that can be supported by a given environment over a sustained period of time. 
* The maximum population size that a particular habitat or ecosystem can sustain without depleting its resources beyond their capacity to recover.
* Determined by its most limiting factor

density independent factor: 

any force that affects the size of a population of living things regardless of the density of the population