In general, from the beginning of the 20^th century, the ecosystems including maritime juniper have been practically destroyed or profoundly disturbed. Depending on the time and place, the factors which have had an influence in this process, whether jointly or separately, have been as follows: urban development, uncontrolled felling, crops, reforestation with pine trees, invasion by exotic species and the construction of different types of infrastructures.

In the Region of Valencia, the maritime juniper is one of the most threatened botanical species and is protected by European, national and regional legislation. It grows exclusively in coastal areas, which have been extensively urbanised.

Concretely in la Devesa de l’Albufera of Valencia, the main threats and causes which have brought about the regression of this species are:

1. The regression of the habitat. Caused by the urban transformations of the 60s and 70s and, and by the fact that the sand from the sediments from the rivers is retained by the reservoirs or the large breakwaters distributed along the coast. This sand is what nature would use for the growth and maintenance of la Devesa.

2. Forest fires. These take place mainly during the summer.

3. The transformation of the dune habitats. This is a consequence of the urban transformations of the 60s and 70s responsible for the devastation of dune ridges and the construction of many infrastructures.

4. Fragmentation of the habitat. The few zones where it is still able to survive are dispersed and located in less than optimal areas.

5. Disproportion between the number of trees of each sex. At the moment only 25% of the trees are female.

6. Reduced wild population. At present, the natural population is reduced to 52 trees. This implies a genetic impoverishment of the species which could mean its extinction in the area.

7. The maresía effect. When the ridges of dunes were flattened during the 70s, the polluting atmospheric agents present in the sea spray directly affected the vegetation. The trees suffering from this maresía effect are in a less healthy state. This has repercussions on their growth and on the production of seeds, certainly due to the fact that they are more likely to catch diseases, which can also lead to their death.

On the other hand, when a juniper forest is reduced, mammals which disperse the seeds (foxes, badgers) begin to lack grazing grounds and their population diminishes. This has a double effect. On the one hand, the juniper seeds are dispersed with greater difficulty and, on the other, when these carnivores disappear, rabbits which destroy large amounts of juniper seeds and seedlings start to proliferate.