Landscape – Great Idea! X-LArch III - Department für Raum ...

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wild species need linear circulations for reproduction
and movement and the fragmentation of natural habitats
causes the loss of biodiversity.In the framework of
landscape ecology and other architectural and ecological
disciplines, a new landscape approach to prevent
against landscape fragmentation and the consequent
loss of biodiversity in the context of urban regions has
been proposed (Forman 2003, 2004, 2008, Gleargeau
2007, Adams 2005). A territorial mosaic conformed by
a diversity of elements (public and private) more or less
connected structure the landscape mosaic:
1) The matrix (the homogeneous and major component,
(normally the periurbain agricultural landscapes),
2) the patches (major foresters habitats, wetlands,
reserves and periurban parks) and the corridors (natural
linear connections between patches: hydrological
system [1], non functional train railways, roads),
the buffer zones (protection zones: borders of rivers,
forests and highways ) and the barriers (obstacles:
highways, water features).
Greenways, Corridors and Ecological Networks are very
similar concepts and they have been integrated in landscape
architecture, urban ecology and recently in wildlife
ecology [2]. Ahern’s definition is inclusive: greenways are
“networks of land linear elements that are planned, designed
and managed for multiple purposes, including ecological,
recreational, cultural, aesthetic or other purposes
compatible with the concept of sustainable land use
(Ahern 1995, p 3). A hedge is a corridor for landscape
ecology that studies the movements of forest species,
and a greenway is used to manage an environmental
linear element (Burel et Baudry 1999: p 299). The edge
can by also part of a horsing trail like in Colver equestrian
network. We can distinguish three types of corridors: a)
natural corridor (rivers, linear wetlands, forests, semi-natural
corridors (hedge ways, trails, tree lined) and artificial
corridors (channels, high tension lines and avenues), But
it is important to recognise that hedges can also work as
a barrier for those animals who like open spaces (deer
and other bigger mammals). Corridors and ecological
networks exist in different scales: continental, regional,
country, region or canton, intercommunal, periurban and
neighbourhood. Not much work has been developed to
study particularly periurban ecological networks.
The hypotheses of co-occurrence or the inherent
multifunctional condition of landscape connectivity
The hypothesis about improving the connectivity between
patches by corridors in urban contexts can be beneficial
for the biodiversity but also for its citizens is a common
approach to landscape ecology, landscape architecture,
urban ecology and recently for wildlife ecology and
urban landscape ecology (Forman 2008, Jongman 1998,
Burel et Baudry, Ahern 1995, Briffet 200, Clergeau 2007,
Adams). This condition is called by Jack Ahern the theory
of co-ocurrence. This theory “posts that in any cultural
landscape greenway resources are spatially concentrated
along corridors “ (Ahern 2003, p 37, 38). This hypothesis
has been confirmed by Philip Lewis, a landscape
architect, who exposed in 1964 that 90% of the ecological,
recreational, cultural and historic resources occurred
along corridors. Ahern, in his article exposed the multiple
benefits of connectivity in greenways and landscape
corridors:
1) connectivity in hydrological systems is a key attribute
for the flow of water and to restore continuous riparian
zones along watercourses,
3) for wildlife movement and reproduction
4) maintaining biodiversity in landscapes that are
urbanising
5) human recreation, and support for cultural landscapes
6) to support alternative forms of transportation,
7) to reduce the impact of human presence and disturbance
by managing the time, place, and intensity
of recreational access. (List adapted form Ahern
2003).
It is worth highlighting the fact that these corridors and
ecological networks have a double essential function:
ability to function as an ecological structure of biodiversity
conservation thanks to landscape connectivity
and as a socio-cultural landscape network to provide a
diversity of natural public spaces. Today, the introduction
of ecological corridor networks can be part of a renewed
approach for conservation of urban regions and
periurban territories. It is worthwhile to join urban parks
with forest, wet lands and rural landscapes by corridors,
for the people that live in urban agglomerations. It is
necessary to establish regional and local governance of
the natural landscape to conserve and improve wildlife
quality by ecological networks. Ecological networks can
improve the social health (Adams 2005, page 151) and
the integration of human activities with the conservation
of biodiversity is arguably one of the greatest challenges
we facie today (Cooperrider, 1992 p,142). How to study
the landscape connectivity and the socio-cultural role of
ecological - periurban - networks? In accordance with
Briffet, two scales of planning decisions are necessary
(macro-scale and micro-scale) . A monitoring of human
and biodiversity and a programme of daily care is
required to keep landscape in given conditions. (Briffet
2001, p, 139). Three main subjects have been suggested
by Briffet ( Briffet 2001, p 141) to manage human needs
for recreation and wildlife for movement ( Fleury and
Brown, 1997,p.185):
1) Landscape compatibility conditions : maintain
accessibility and continuity for both people and
wildlife,
2) conserve and develop diversity of habitat,
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