Glossary 2018-10-18T10:48:29-04:00

Glossary

A

Evaluating connectivity through an estimation of both the length of the least-cost path between patches, as well as the underlying ecological cost incurred to travel it.

A style of management that assumes continual monitoring of the landscape and allows for the flexibility of adjusting conservation goals to shifting conditions.

A specific process or set of rules to solve a problem.  For example, algorithms from graph theory can be applied to calculations of connectivity in the landscape.

Caused by or relating to humans.

The act of physically moving individuals from one location to another.  This is a suggested management strategy, particularly for species who have difficulty dispersing and who may be under immediate threat of losing suitable habitat due to climate change.

B

When mapping potential corridors, a barrier is any physical object or type of landscape that prevents an individual from moving between patches.

C

A group of landscape metrics that measures how important a patch is in allowing species to “flow” through the landscape i.e. how central the patch is to other patches.

The idea that connectivity in a landscape can be modeled like an electrical circuit map, with properties like resistance and current having ecological counterparts like individual movement and gene flow.

Patches of habitat that will remain suitable for species even as climate change alters current habitats.  For example, high elevation mountaintops may act as climate refugia in the future for many lowland species, since they will remain (relatively) cool under climate change.

A corridor or other landscape form that connects current habitat to climate refugia.

The act of one or more species inhabiting a new patch where the species was not previously found through individual dispersal, and where individuals chose to remain to live and breed.

A measure of how easy it is for individuals to move between patches of suitable habitat. Low connectivity between patches can ultimately lead to decreased biodiversity due to the disruption of dispersal, migration and/or genetic flow.

Refers to a species that can only persist in the wild as long as it has management intervention.

The central area within a patch or home range that generally defines where an individual is most likely to be found.

Any habitat whose main function is to connect isolated patches of suitable habitat that would otherwise be inaccessible to some or all species.

Also measured as resistance, the amount of effort required to move through the landscape.

D

An individual’s ability to travel for the intention of permanent relocation. A main goal of dispersal is to find new suitable habitat with better opportunities for territory, resources, and/or mates.

Any temporary disruption to the natural habitat that causes a long-term change in the ecosystem. Can occur naturally (ex. lightening fire, hurricane, conversion to wetland by beavers) or be man-made (ex. logging, road construction, wetland drainage).

E

The benefits provided to humans by many species when ecosystems are fully functioning (ex. pollination by bees, water filtration in streams, carbon storage).

The propensity for species to behave differently at habitat edges (ex. the border between field and forest), which can be a concern when designing corridors.

 

F

An aerial corridor used by any volant species to migrate or move long distances.

The breaking up of a habitat patch into smaller pieces. It can be the result of many factors, such as urbanization, resource extraction or conversion to agriculture.

The degree to which the landscape allows species-specific movement between patches i.e. connectivity from a species’ perspective.

G

A framework for organizing and integrating spatial or geographic data so that it can be analyzed for connectivity or other landscape features.

The transfer of genetic material through a population, which can be used as a measure of how connected populations are.

The degree to which populations have a high level of gene flow between them.  Populations have high genetic connectivity if there is high gene flow and low diversity between populations.

A framework used to extract maximum efficiency of connectivity in networks, with connectivity defined by dispersal probability and referenced between nodes.  In ecology, nodes represent patches in a fragmented landscape, with the probability of dispersal between them occurring along corridors.

H

The idea that species richness in habitat patches is dependent on habitat amount, rather than patch size and isolation, as suggested in Fahrig 2013.

Something that has mixed composition, such as a forest that contains a high diversity of trees.

Something that is of uniform composition, such as a forest that contains only one species of tree.

I

A species that is not naturally found in a location (i.e. native) and often competes and spreads aggressively in order to survive. Examples of invasive species include cane toads (Rhinella marina) in Australia, kudzu (Pueraria lobata) in the United States, and brown tree snakes (Boiga irregularis) in Guam.

A theory that attempts to explain patterns of species diversity on islands or island-like habitats. It suggests that island size and distance from mainland are major factors that determine diversity. In general, a larger island can support more species than a small one and an island closer to the mainland is more likely to be colonized than a more distant one.

J

K

L

Recurring landscape units of relatively uniform topography and soils.  One conservation strategy is to use land facets as coarse units to protect biological activity in general rather than protecting individual species within an area.

Indices developed to explain landscape structure and changes on a map.  Examples of landscape metrics include patch area, patch connectivity, number of patches, total edge, degree of isolation, or patch distribution.

Methodology to determine potential linkages by estimating the least detrimental route a species might take for dispersal (ex. a short route through preferred habitat).

Physical structures or facilities that are configured as a line, such as roads, highways, tracks, railways, power lines, or pipelines.  Linear infrastructure often acts as a barrier to animal movement, but can sometimes act as a corridor for species that are able to utilize the remaining habitat within the infrastructure.

General term referring to any connection between habitats, regardless of size, composition or configuration.

M

The surrounding environment in which a habitat (including a corridor) is embedded. Often contrasts to the embedded habitat, and may be inhospitable to or difficult to move through for species that live in the embedded habitat.

A smaller, enclosed version of an ecosystem used to replicate natural conditions for experimental purposes.

The idea that a large population may consist of smaller fragmented populations linked through genetic flow. Although individual subpopulations may go extinct or reappear over time, the metapopulation can still remain stable through dispersal and recolonization.

An aerial flyway used by migrating species.  Migratory corridors are not necessarily represented as a continuous terrestrial corridor, but rather a long-distance flyway that includes stopover points.

Clustering within networks into modules (ex. local populations or patches) that are tightly linked to themselves and sparsely linked to other modules (such as the larger population or network of patches).

N

The idea that connectivity in landscape can be viewed as an interdepenent network, and that changes in nodes and linkages can have unexpected consequences for species movement.

A central point connecting two or more linkages, often used when generating maps of potential corridors.  Nodes on a map can be represented in real life by parks, protected areas, conservation easements, or other large patches of undeveloped land.

O

Modeling whether individuals are present in any given patch given survey data from a proportion of all patches, with the assumption that the detection rate is less than one.

P

A central area of habitat that is distinguished from its surrounding matrix, such as an island of forest surrounded by agricultural fields.

The degree to which habitat (such as the matrix) allows for individuals to move through it.

The ability of a trait to be flexible in its expression.

A location afforded special status due to its ecological importance.  Protected areas can be terrestrial or marine, and level of conservation protection can vary by location.

Q

R

The change in a species’ range to expand in a different direction than previously observed. Climate change is predicted to cause a northward and/or upward range shift for some species as temperatures increase.

A type of data used in Geographic Information Systems that codes information as a grid.  Information is held within each pixel, rather than as a discrete object such as a point or line (vector).

The probability that an individual will move through a landscape. Higher resistance equals a lower likelihood of movement.

A method used to determine how species use resources within and area, and to make predictions about how landscapes can be better connected based on resource use.

The area next to a river or stream that supports hydrophilic terrestrial species, often unique from more upland species.

S

A population that is decreasing (deaths > births) due to low quality habitat or other detrimental qualities of the landscape.

A population that is increasing (deaths < births) due to high quality habitat or other beneficial qualities of the landscape.

An intermediate island or island-like habitat that may not support individuals long term, but can be useful as a way point for connecting suitable habitats that are far apart in the matrix.

Randomness.  Environmental conditions are often described as stochastic because they have a high degree of unpredictability.

The degree to which the landscape is spatially configured to allow patches to remain connected.

Whether or not a region in the landscape is able to support species.  An area that has high suitability for one species may have low suitability for another species.

T

The point at which conditions shift, potentially to a degree that they cannot be reversed.

The position that an individual occupies in the food chain.

U

A species used as a representative for all species of a particular type of habitat, often well-known and of particular conservation concern.  This species acts as an “umbrella” for all other species under it: if its habitat is protected, then all other species in that habitat will benefit from the protection.

V

W

The amount of cost (or resistance) assigned to an area or pixel that represents the degree of difficulty for an individual to move through the landscape.

A bridge or other structure designed to allow individuals to safely cross a barrier such as a road or railway.

X

Y

Z