Habitat Fragmentation
What is Insularization in regards to no patch connectivity?
When patches are no longer accessible due to barriers such as road. This reduced area leads to patches becoming isolated from one another. This leads to inbreeding
Describe the Initial Exclusion of Species...
When species are eliminated in gaps due to no connectivity.
Why do pandas more than other species need their habitat protected?
They are habitat specialists
In addition to road mortality, what other problem do roads pose?
They bring people into an area.
Habitats are often fragmented into Patches, how can these patches vary?
They can vary in size and quality
To help maintain biodiversity, what can we provide for habitat patches?
We can help provide connectivity between patches.
How do we fix these issues of habitat fragmentation and isolation?
We create connectivity between patches through the formation of corridors
What is an ecological trap? Why can these be misleading?
When changes in microhabitat are attractive too some species but make them more vulnerable to predation. Can seem good since it increases biodiversity but introduced species can disrupt functions.
To preserve biodiversity in an area, it is vital that we protect the...?
Habitat
What is inbreeding depression? example?
Reduced fitness due to inbreeding. Florida Panthers
what are the three main consequences of having no connectivity between habitat patches?
1) Initial Exclusion of Species 2) Crowding Effect 3) Insularization
What are the main problems with corridors?
1) We don't know if species will actually use them 2) It can potentially make species more vulnerable
What is a matrix in regards to their relation to habitat patches? what is a primary example of something that creates a matrix among patches?
A matrix is the space between habitat patches. Roads are a primary example
What does a decrease in core habitat result in?
A reduction of species composition
What is a Charismatic Megafauna? Examples?
Any animal that will get people excited about conservation. Tigers, lions, pandas or giraffes.
How can we support wild populations?
By increasing the available habitat for them
What is the best combination of habitat and corridors?
Circular habitat + corridor connectivity
What are edge effects? What can they do? What species tend to like the edges of communities?
Drastic changes in microclimate at modified edges of communities. They can alter biodiversity. Invasive species tend to like community edges since they are usually disturbed areas.
What does Landscape Ecology focus on and why?
Focuses on causes and ecological consequences of spatial patterns. Allows observations at a regional scale. What happens next to a habitat is just as important.
What does fragmentation lead to an increase in? Decrease in? (In terms of available habitat)
Increase in edge habitat. Decrease in core habitat.
Describe the crowding effect in relation to having no connectivity between patches...whats an example of this?
Initially, this will lead to a sharp increase in population size because all individuals will flock to what habitat is left. This is then followed by a large populations number drop off and many die. Spotted owls are an example
How can the Crowding Effect be misleading in terms of species conservation?
It can give the impression that the population numbers are increasing when in reality they are not.
What do these three main consequences of no connectivity lead to?
Reduced population numbers which leads to reduced biodiversity.
What is the main problem with roads?
Killing species by running them over.
What shape of habitat is the best and why?
Large circular habitats since they have greater core patches.
How can matrixes have profound effects on neighboring patches?
Loss of nutrients and other resources. Can restrict gene flow
How are people driving to a new area bad for that area?
Lots of negative effects Pollution Dispersal of exotics
What does road mortality create?
Serves as a barrier between patches and prevents gene flow.
What are the two types of patches?
Source patch Sink patch
What is a source patch and what is a sink patch?
Source patch: Larger areas of habitat Sink patch: Places for organisms to migrate to
When a big habitat is greatly reduced in size to a small habitat, what effect does this cause?
The crowding effect
How has the Brown headed Cowbird benefitted from fragmentation?
Their population numbers have quadrupled since edge effects put them at an advantage.
Does the amount of suitable habitat required differ between species? Example?
Yes, elephants require about 400km^2 of habitat.
What is the Crowding Effect?
when the remaining members of a population are forced to inhabit the same area due to habitat reduction.