Nature, food, and water 249and us, and (4) streams, rivers, and blue-green ribbons, are presented in this
section. The other three: (5) growth, development, and municipalities, (6) trans-
portation and industry, and (7) nature and people in municipalities, emerge in
the following section.
Emerald network
Large natural-vegetation areas or patches interconnected by vegetation
corridors form the emerald network (Forman 2004a). This is the fundamental
backbone of natural systems protection in a landscape or region, thepiece de
resistanceof the Greater Barcelona Region (Color Figure 41 ). The network pro-
vides numerous values, from a permanent buffer against species extinction to
alimit against endless urbanization, and is composed of emeralds and connec-
tions. Two solutions were outlined: (1) emeralds, the crown jewels of nature; and
(2) connected land: five types of connections.
Emeralds, the crown jewels of nature
Large natural-vegetation areas or emeralds provide a group of benefits
that cannot be provided in any other way, including: water quality protection
foraquifers; connectivity of headwater streams; habitat to sustain populations
of patch-interior species; a source of species dispersing through the matrix and
tosmall patches; and ability to absorb or persist through natural disturbances
over time(Forman1995). Additional important benefits for society include flood
control, adequate water for sewage treatment facilities, aesthetics, biodiversity,
wood products, and recreational opportunities from family picnicking to bird
watching, hunting, hiking, and youth education (Parcde Collserola1997,Liddle
1997,Bacariaet al.1999,Rodaet al.1999,Blondel and Aronson 1999, Atauri and
de Lucio2001,GroveandRackham2001).
Eight large protected natural areas currently exist in the Greater Barcelona
Region (Garraf, Collserola, Montnegre-El Corredor, Montseny, Sant Llorenc del
Munt, Montserrat, Serra de Castelltallat, and Serralada Transversal) (Rodaet al.
1999,Acebillo and Folch2000), and two additional ones are proposed. The
Ancosa-Miralles emerald (west of the Penedes) combines and gives integrity to a
cluster of five separate medium and small existing protected areas, and fills a
void in the western quarter of the Region. The Serra de Rubio emerald (north
of Igualada) connects headwater stream areas of the Anoia and Llobregat rivers,
protects some European-Community-listed rare habitats, and helps link the iso-
lated Castelltallat to Montserrat and Ancosa-Miralles. The combination of distinc-
tive predominant vegetation and predominant rock surfaces emphasizes that
all ten emeralds are ecologically important. Three emeralds, Garraf, Collserola,