INTRODUCTION TO LANDSCAPE ECOLOGY:PATCH / MATRIX / EDGE / MOSAIC

HARVARD GSD CAREER DISCOVERY 2013

Animals, plants, water, wind, materials, and peo-ple move through spatial patterns characteristic of virtually all landscapes and regions. Th is up-to-date synthesis explores the ecology of hetero-geneous land areas, where natural processes and human activities spatially interact to produce an ever-changing mosaic...Th is subject is of enor-mous importance to today’s society, and indeed for molding the future of areas surrounding each of us.

-Richard T.T. Forman, introduction to Land Mosaics: Th e Ecology of Landscapes and Re-gions

LANDSCAPE ECOLOGYLINEAGE:

IAN MCHARG

LANDSCAPE ECOLOGYLINEAGE:

HOWARD T. ODUM

LANDSCAPE ECOLOGYLINEAGE:

RICHARD T.T. FORMAN

Mosaic: a pattern of patches, corridors and matrix, each composed of smaller, similar, aggregated ob-jects; the pattern created by the juxtaposition of these forms

Matrix: the background ecosystem or land-use type in a mosaic, characterized by extensive cover, high connectivity, and/or major control over dynamics.

Patch: a relatively homogenous area that diff ers from its surroundings (ex. a grove, a thicket, an opening)

Corridor: a strip of a particular type that diff ers from the adjacent land on both sides (ex. a river corridor, hedgerow or a high transmission powerline corridor)

LANDSCAPE ECOLOGY

RICHARD T.T. FORMAN

Mosaic: a pattern of patches, corridors and matrix, each composed of smaller, similar, aggregated ob-jects; the pattern created by the juxtaposition of these forms

Matrix: the background ecosystem or land-use type in a mosaic, characterized by extensive cover, high connectivity, and/or major control over dynamics.

Patch: a relatively homogenous area that diff ers from its surroundings (ex. a grove, a thicket, an opening)

Corridor: a strip of a particular type that diff ers from the adjacent land on both sides (ex. a river corridor, hedgerow or a high transmission powerline corridor)

MOSAIC: a pattern of patches, corridors and matrix, each composed of smaller, similar, aggregated objects.

MOSAIC: a pattern of patches, corridors and matrix, each composed of smaller, similar, aggregated objects.

Top: Industrial park, Golf course community, Planned suburb, Landfi ll, Agriculture (corn/soybean), Agriculture (circle Irrigation)

“Form is the diagram of force.”

PATTERNS OF FRAGMENTATION AND DISTURBANCE

1_SUBSTRATE HETEROGENEITY soil type, water, solar energy

PATTERNS OF FRAGMENTATION AND DISTURBANCE

1_SUBSTRATE HETEROGENEITY soil type, water, solar energy

2_ NATURAL DISTURBANCE fi re, wind, storms, mudfl ows

PATTERNS OF FRAGMENTATION AND DISTURBANCE

1_SUBSTRATE HETEROGENEITY soil type, water, solar energy

2_ NATURAL DISTURBANCE fi re, wind, storms, mudfl ow 3_HUMAN DISTURBANCE sprawl, resource extraction agriculture, policy

PATTERNS OF FRAGMENTATION AND DISTURBANCE

1_SUBSTRATE HETEROGENEITY soil type, water, solar energy

2_ NATURAL DISTURBANCE fi re, wind, storms, mudfl ow 3_HUMAN DISTURBANCE sprawl, resource extraction agriculture, policy

While “form is the diagram of force,” it works the other way around as well.

Not only do fl ows create structure, but structure determines fl ow. Th e arrangement of patches and corridors determines the movements of verte-brates, water and humans across the land.

As designers we can study how these arrangements change move-ments and fl ows, learn from them, and apply them in our work.

Mosaic: a pattern of patches, corridors and matrix, each composed of smaller, similar, aggregated ob-jects; the pattern created by the juxtaposition of these forms

Matrix: the background ecosystem or land-use type in a mosaic, characterized by extensive cover, high connectivity, and/or major control over dynamics.

Patch: a relatively homogenous area that diff ers from its surroundings (ex. a grove, a thicket, an opening)

Corridor: a strip of a particular type that diff ers from the adjacent land on both sides (ex. a river corridor, hedgerow or a high transmission powerline corridor)

PATCH:

a relatively homogenous area that diff ers from its surroundings (ex. a grove, a thicket, an opening)

MATRIX:

the background ecosystem or land-use type in a mosaic (ex. grassland, forest, crop land, urban fabric)

Patches have ecological value based on size. Th e greater the patch size of continuous vegetation, the higher the biodiversity.

Each species has a minimum size of habitat needed for survival. A larger patch provides habitat for more spe-cies, from a single Plueteus mush-room to a black bear. A smaller patch could contain only the Plueteus.

SMALL:FungiInsectsLichen

MEDIUM:FungiInsectsLichen

HERBIVORESSparrowBlue JayRabbitSquirrel

LARGE:FungiInsectsLichen

HERBIVORESBlue JayRabbitSquirrelDeerBeaver

CARNIVOREBlack bearFox

Large patches:1_Water quality protection for aquifer and lakes2_Connectivity for a stream network for fi sh and overland movement.3_Habitat to sustain populations of patch interior species.4_Core habitat and escape cover for large-home-range vertebrates5_Source of species dispersing through the matrix6_Microhabitat proximities for multihabitat species7_Near natural disturbance regimes8_Buff er against extinction during environmental changes

Small patches:1_Habitat and stepping stones for species dispersal, and for recoliniza-tino aft er local extinction2_High species density and high populations of edge species3_Increases heterogeneity of the landscape 4_Habitat for small-patch species

Ecological value of patches of vegetation:

Patch shape is very important.

Edges and interior spaces of patches provide diff erent habitat for diff er-ent species. As the ratio of interior to edge increases, the biodiversity increases, providing more habitat for interior species (esp. predators and carnivores).

Rounder shapes accomodate more interior species, which elongated shapes accomodate more edge spe-cies.

Again, patch shape is very impor-tant.

PATCH + FRAGMENT

Fragmentation of habitat is the transformation over time from a larger expanse/patch to smaller, more dispersed patches.

Fragmentation of patches increases the ratio of edge to interior, thus reducing biodiversity and infl uencing species distribution.

PATCH GRAIN + SCALE

Diff erent scales of an opening or a patch (i.e. the coarseness or fi neness of the grain of the landscape) attract diff erent species and uses.

PATCH GRAIN + SCALE

Diff erent scales of an opening or patch (i.e. the coarseness or fi neness of the grain of the landscape) attract diff erent species and uses.

Th is goes for human uses as well. A large opening might encourage a soccer game, while a smaller one might better suit a romantic picnic.

MOVEMENT BETWEEN PATCHES

1_ A small population on a small patch of land is fragile, and less likely to remain (aka the Castaway Phe-nomenon).

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MOVEMENT BETWEEN PATCHES

1_ A small population on a small patch of land is fragile, and less likely to remain.

2_ A small population near a big patch increases chances of survival. Must be close enough to another patch that once in a year or lifetime it can move from the small to the big patch (aka. Th e Joe Versus the Vol-cano Phenomenon.)

d = distance that can be crossed by a species

MOVEMENT BETWEEN PATCHES

1_ A small population on a small patch of land is fragile, and less likely to remain.

2_ A small population near a big patch increases chances of survival. Must be close enough to another patch that once in a year or lifetime it can move from the small to the big patch.

3_Th e distance travelled between patches varies per species, and wild-life corridors improve the connectiv-ity between patches (aka. Th e Run Forrest Run Phenomenon).

EDGE SHAPE IS IMPORTANT

A straight boundary encourages movement along an edge (i.e. cor-ridor), while a more convoluted edge encourages movement across an edge or boundary (i.e. between two habitats).

EDGE SHAPE IS IMPORTANT

Th e soft ness or the hardness of an edge aff ect the depth of the edge eff ect and the depth of disturbance into the interior of a patch (i.e. increased wind, sun, etc). Th is eff ects the depth of habitat for edge versus interior species.

Hedges planted at the edge of a forest can create a veil to improve habitat for certain species.

EDGE SHAPE IS IMPORTANT

Many English landscape designers, including Capability Brown, would vary edge conditions to create con-voluted edges and hedge borders to increase the breeding grounds for one very infl uential edge species: the pheasant.

Gardens and grounds, Stowe House, Buckingham, Bucking-hamshire, United Kingdom

Mosaic: a pattern of patches, corridors and matrix, each composed of smaller, similar, aggregated ob-jects; the pattern created by the juxtaposition of these forms

Matrix: the background ecosystem or land-use type in a mosaic, characterized by extensive cover, high connectivity, and/or major control over dynamics.

Patch: a relatively homogenous area that diff ers from its surroundings (ex. a grove, a thicket, an opening)

Corridor: a strip of a particular type that diff ers from the adjacent land on both sides (ex. a river corridor, hedgerow or a high transmission powerline corridor)

CORRIDORS

Corridors can be naturally occur-ing (like the stream corridor on left ), or constructed (like the powerline transmission corridor on the right).

CORRIDORS

Corridors can be wider strips or nar-row lines. Th ey can also be positive forms of vegetation or negative open-ings within a matrix.

CORRIDORS

Corridors can function as habitat, conduits, fi lters, sources of species, or sinks to facillitate fl ows and move-ment.

ROAD AS CORRIDOR

ROAD CORRIDORS

Th e width of a road or any corridor eff ects which species can cross, thus acting as a species fi lter,

ROAD CORRIDORS

Road corridors can also prove con-nectors for certain species that travel down rather than across such cor-ridors. One such benefi ciary of the road system is the coyote which has found its way into urban and sub-urban settings, including Chicago where they fi nd plentiful prey in urban wildlife and domesticated pets.

ROAD CORRIDORS

Th e distance from a road corridor ef-fects the adjacent areas. For example, lead and salt from roads can impact areas up to 100 meters away.

CORRIDORS + CONNECTORS

Biodiversity and mobility of species can be increased by creating cor-ridors or sinks (i.e. small patches) between patches.

CORRIDOR

SINKS

CORRIDORS + CONNECTORS

Hedgerows and windbreak act as connectors for wildlife fl ow, while reducing wind to improve pasture and crop conditions.

APPLICATION

Given these rules, one can begin to understand and map how movement of wildlife and people respond to a landscape matrix.

“Using principles is not diffi cult, and leads to more integrative designs and plans. It helps reduce the landscape fragmentation and degradation so evident around us.”

-Richard T.T. Forman

APPLICATION:VEGETATION AS REMOVAL