The Program was developed between 2002 and 2006 with a total cost of
1,269,893 Euros. Various field work projects cost 860,250 Euros, and the technical
works for the development of control and monitoring activities, research, dissemination of information, and environmental education 409,643 Euros in two
phases (2002–2004: 146,000 Euros; 2004–2006: 263,643 Euros).
9.6 A Field Experiment in the Enebrales de Punta Umbría
Natural Landscape
The Enebrales de Punta Umbría Natural Landscape (162 ha), located southward
of Huelva city (southwest Spain) and protected since 1989, shows the problems of
juniper woodlands under pine tree plantations (Pinus pinea). Here, along a sandy
strip 2.5 km long and 200 m wide, approximately 300 mature maritime junipers
without natural regeneration survive under a pine tree canopy. Anthropic pressure
is intense, and the junipers are accompanied by Phoenicean juniper (Juniperus
phoenicea subsp. turbinata) and a xerophytic shrub composed of Cistus salvifolius,
Halimium halimifolium, Rosmarinus officinalis, Rhamnus lycioides, and Pistacia
lentiscus, among others.
Within the framework of the ‘‘Conservation Program of Maritime Juniper
Woodlands,’’ a clearing experiment was carried out in this protected nature
reserve. The general aim of the pine tree treatments was to reduce their negative
effects on maritime junipers and to restore the environmental conditions to favor
the regeneration of natural coastal plant communities. We analyzed the effects of
three levels of pine tree clearing on the physical environment, the junipers’ performance, and the coastal plant community.
Pine tree plantation clearings were carried out in January 2004, with three
levels of pine removal:
1. Without pine clearfelling (dense canopy),
2. Removing the closest pine trees to the junipers (light clearing),
3. Removing all the pine trees and the largest Phoenicean junipers (clearings).
The original experimental design included three paired 50 9 50-m plots from
the top of the first dune front, but it was not approved and needed to be reduced.
Finally, treatments 1 and 3 were each applied to two adjacent 30 9 30-m plots
located within the dune valley. The light clearing treatment was applied extensively in the rest of the area with junipers. The first exploratory analysis showed
that plant cover and physical variables were similar in treatments 1 and 2.
The physical environment variables monitored were salt spray deposition,
photosynthetic active radiation (PAR), and sand mobility. Juniper performance
included cone and seed production in 2003 and 2006, growth of branches, and the
density of pollen in the air. The establishment of sand dune plants in the clearings
was also recorded.
154
J. C. Muñoz-Reinoso et al.
1,269,893 Euros. Various field work projects cost 860,250 Euros, and the technical
works for the development of control and monitoring activities, research, dissemination of information, and environmental education 409,643 Euros in two
phases (2002–2004: 146,000 Euros; 2004–2006: 263,643 Euros).
9.6 A Field Experiment in the Enebrales de Punta Umbría
Natural Landscape
The Enebrales de Punta Umbría Natural Landscape (162 ha), located southward
of Huelva city (southwest Spain) and protected since 1989, shows the problems of
juniper woodlands under pine tree plantations (Pinus pinea). Here, along a sandy
strip 2.5 km long and 200 m wide, approximately 300 mature maritime junipers
without natural regeneration survive under a pine tree canopy. Anthropic pressure
is intense, and the junipers are accompanied by Phoenicean juniper (Juniperus
phoenicea subsp. turbinata) and a xerophytic shrub composed of Cistus salvifolius,
Halimium halimifolium, Rosmarinus officinalis, Rhamnus lycioides, and Pistacia
lentiscus, among others.
Within the framework of the ‘‘Conservation Program of Maritime Juniper
Woodlands,’’ a clearing experiment was carried out in this protected nature
reserve. The general aim of the pine tree treatments was to reduce their negative
effects on maritime junipers and to restore the environmental conditions to favor
the regeneration of natural coastal plant communities. We analyzed the effects of
three levels of pine tree clearing on the physical environment, the junipers’ performance, and the coastal plant community.
Pine tree plantation clearings were carried out in January 2004, with three
levels of pine removal:
1. Without pine clearfelling (dense canopy),
2. Removing the closest pine trees to the junipers (light clearing),
3. Removing all the pine trees and the largest Phoenicean junipers (clearings).
The original experimental design included three paired 50 9 50-m plots from
the top of the first dune front, but it was not approved and needed to be reduced.
Finally, treatments 1 and 3 were each applied to two adjacent 30 9 30-m plots
located within the dune valley. The light clearing treatment was applied extensively in the rest of the area with junipers. The first exploratory analysis showed
that plant cover and physical variables were similar in treatments 1 and 2.
The physical environment variables monitored were salt spray deposition,
photosynthetic active radiation (PAR), and sand mobility. Juniper performance
included cone and seed production in 2003 and 2006, growth of branches, and the
density of pollen in the air. The establishment of sand dune plants in the clearings
was also recorded.
154
J. C. Muñoz-Reinoso et al.