272 The Barcelona Region’s land mosaic
agricultural system, transportation system, groundwater system, stream/river
system, and economic system are all examples present in the region. Negative
feedbacks in systemsinherently provide stability. Also several of the systems
contain a hierarchy that may also provide stability.
Redundancyor multiple components is another way to offer flexibility. Main-
taining five major agricultural landscapes rather than fewer, four important
rivers with clean water rather than one or none, ten major emeralds rather
than eight, two major floodplain/delta aquifers rather than one or none, and
so on, provides for stability. Optional routes for flows and movements also help
accomplish the broad goal. Emeralds with three or four connections to other
emeralds mean that with, e.g., climate change or new urbanization pressure,
species may move in different directions to more suitable locations.
Still another key dimension of flexibility and adaptability isdiversity. Main-
taining five types of major agricultural landscape, six types of natural emerald,
five types of satellite city, and so forth is better than one type of each. When
adisturbance or disease degrades or eliminates one type, the other four still
sustain resources.
Current trends are certainly threatening the future of some resources, such
as water-supply reservoirs, floodplain/delta aquifers, agricultural resources, and
coastal water quality in the Barcelona Region. The diverse types of flexibility and
adaptability built into the three plans should enhance stability for the region’s
future.Major results and recommendations
Nine major results and recommendations resulting from specific analy-
ses are listed (Forman 2004a). Other results from finer and broader lenses could
be highlighted. Two succinct broad conclusions are illustrative. The urban region
as a distinct area matters in a big way. Natural systems and their uses in the
region matter even more:(A) The ‘‘ emerald network” as the backbone of natural systemsin the region is
asystem of connected large natural park areas, which provide aquifer
protection, wildlife movement, trails for walking and recreation, nature
conservation, and other benefits for society.
(B) Aset of diverse large agricultural areas plus smaller ‘‘ agriculture--nature parks”
provides food production, open land, important successional habitats,
and economic flexibility.
(C) Protected highest-quality stream valleys and widespread restored small wetlands
significantly enhance aquatic ecosystems, biodiversity, and paths for
walking.