Module 32
Define matrix
"background ecological system, high degree of connectivity"
By increasing movement between connected patches of habitat, corridors ___,____,___,
- Increase gene flow - Promote reestablishment of locally extinct populations - Increase species diversity
A landscape with structure and pattern implies that it has spatial heterogeneity, what is this?
A key element of landscape ecology, this means the uneven distribution of objects across the landscape
What is an ecocline?
A landscape boundary, but it has a gradual and continuous change in environmental conditions of an ecosystem or community. They help explain distribution/diversity of organisms within a landscape because certain organisms survive better under certain conditions, which change along the ecocline. They contain heterogeneous communities which are considered more environmentally stable than those of ecotones.
What is an ecotope?
A spatial term representing the SMALLEST ecologically distinct unit in mapping and classification of landscapes. relatively homogenous useful for measuring landscape structure, function, and change over time, and to examine the effects of disturbance and fragmentation.
Areas with small habitat fragments exhibit especially pronounced edge effects that may extend throughout the range. As the edge effects increase, the boundary habitat allows for greater biodiversity.
Basically small habitat- more edge effect more edge effect- more diversity
Define corridors, network, and mosaic
Corridors have important functions as strips of a particular type of landscape differing from adjacent land on both sides. A network is an interconnected system of corridors while mosaic describes the pattern of patches, corridors, and matrix that form a landscape in its entirety.
True or false: Edges don't change through time, once it's there its there
False (Edges are dynamic and may change thru time)
How do we study landscapes?
Geographic Information Systems (GIS) used to gather data over large spaces
The "island" distance and size is really important for deciding the amount of species richness
If the island is bigger/closer, it gets more chance of diversity/richness from the mainland. If the island is farther away/smaller, it gets way less chance of diversity/random dispersion
What is the landscape ecology theory
It stresses the role of human impacts on landscape structures and functions. It also proposes ways for restoring degraded landscapes.
________ ________ is the science of studying and improving relationships between ecological processes in the environment and particular ecosystems.
Landscape ecology
Talk about the types of habitat edges
Narrow- one habitat abruptly ends and another begins (like a farm field) Wide- (aka- ecotone) a large distance separates the borders of two clearly and purely definable habitats based on their physical condition and vegetation, and between theres a large transition region convoluted- the border is non-linear perforated- the border has gaps that host other habitats
What is composition?
Number of patch types represented on a landscape and their relative abundance (amount of forest or wetland, length of forest edge, density of roads)
What is scale when its used in landscape ecology?
Scale represents the real world as translated onto a map, relating distance on a map image and the corresponding distance on earth. Scale is also the spatial or temporal measure of an object or a process, or amount of spatial resolution.
What does the theory of island biogeography propose?
The theory of island biogeography proposes that the number of species found in an undisturbed insular environment ("island") is determined by immigration and extinction. The theory of island biogeography proposes that the number of species found in an undisturbed insular environment ("island") is determined by immigration and extinction. Overtime there is an equilibrium
Define patch
a relatively homogenous area that differs from its surroundings. these are the basic unit of a landscape, and they can change and fluctuate (patch dynamics). they have a definite shape and spatial configuarion and can be described by number of trees, species, height, etc.
What is an ecotone
a type of boundary, this is the transitional zone between two communities. can be natural, like a lakeshore, or can be human made like a farm cleared from a forest.
Define patch dynamics
an ecological perspective that the structure, function, and dynamics of ecological systems can be understood through studying their interactive patches. may also refer to the spatiotemporal changes within and among patches that make up a landscape.
Describe boundary and edge
boundary- zone composed of the edges of adjacent ecosystems edge- the portion of an ecosystem near the perimeter, where influences of the adjacent patches can cause an environmental difference between the inside and the edge. This includes a specific species composition/abundance. For example, when a landscape is a mosaic of perceptibly different types, such as a forest adjacent to a grassland, the edge is the location where the two types adjoin. In a continuous landscape, such as a forest giving way to open woodland, the exact edge location is fuzzy and is sometimes determined by a local gradient exceeding a threshold, such as the point where the tree cover falls below thirty-five percent.
What are the components of a scale
composition structure function
The degree to which a landscape is _____ determines the amount of dispersal there is among patches, which influences gene flow, local adaptation, extinction risk, colonization probability, and the potential for organisms to move as they cope with climate change.
connected
Linear habitat features intended to connect larger habitat patches are termed:
corridors
What is landscape structure?
determined by the composition, configuration and proportion of different patches across the landscape
Video skyepack: colonization depends on the distance from mainland and island.
dude found a bunch of mangrove stands, sprayed them with fumigant, and created diluted "islands" that varied in size and shape. came back and counted insects that arrived and they measured richness. found that remoteness and island size predict the species richness in communities that arise.
The perimeter of each patch is called an ___, which is narrow and abrupt, or it can be wide with a transition zone or ectone
edge (border)
The ____ _____ is the phenomenon where edge communities are often quite diverse
edge effect
True or false: once an edge is there, its there forever, its not dynamic and cant change through time
false
true or false all of the landscapes in the US are homogenous and not fragmented
false
True or false the edge effect causes no problems
false (can attract more predators which is an ecological trap, and it also restricts dispersal)
True or false: island biogeography refers only to islands
false, its used for any ecosystem to describe species richness
Give some examples of ecotones
fencerows, forest to marshlands transitions, forest to grassland transitions, or land-water interfaces such as riparian zones in forests
For plants, the enviornomental conditoins are more important to persistance than is patch size
for bird species theres diversity with patch size, so as the land increases the bird species increases
why is an environment patchy?
geology, soil, flat/hilly, climate, precipitation, human interaction
Patch size AND shape are important. why?
geometry, helps to calculate edge and area
What is landscape function
how each element int he landscape interacts based on its life cycle events
The ___ in pop size is a funciton of the increasing carrying capacity for the species
increase (more area--> more home ranges and territories)
_____ species require conditions characteristic of interior habitats and avoid edges
interior
Landscape ecology theory includes the __________, which emphasizes the importance of landscape structural heterogeneity in developing resistance to disturbances, recovery from disturbances, and promoting total system stability.
landscape stability principle
According to the theory of island biogeography, the islands with the most species will be:
large and close to mainland
In Landscape Ecology, the background ecological system in which habitat patches are dispersed is called the:
matrix
A landscape is often composed of ____ of habitat
patches
What are landscapes
spatially heterogeneous geographic areas characterized by diverse interacting patches or ecosystems, ranging from relatively natural terrestrial and aquatic systems such as forests, grasslands, and lakes to human-dominated environments including agricultural and urban settings.
What is an edge effect?
the change in population or community structure that occur at the boundary of two habitats.
what is landscape pattern
the contents and internal order of a heterogeneous area of land.
Bird edge habitat example
the indigo bunting burd -The male requires tall, open song perches -The female a dense thicket in which to build a nest
define connectivity
the measure of how connected or spatially continuous a corridor, network, or matrix is.
Edge species are those restricted exclusively to the edge environment True or False
true
True or false? The ecotonal community retains characteristics of each bordering community and often contains species not found in the adjacent communities.
true
larger patches are more likely to contain variations of species true or fasle
true
Give some characteristics of ecotones
vegetational sharpness, physiognomic change, occurrence of a spatial community mosaic, many exotic species, ecotonal species, spatial mass effect, and species richness higher or lower than either side of the ecotone.
When is the equilibrium species richness (S) achieved?
when immigration rate=extinction rate it is affected by the distance of the island from the mainland and the size
Dispersal(movement across the landscape) is important for
• Gene flow • Recolonization of extinct habitat patches • Shifting ranges in response to climate change