observation showed that annual plants such as Rumex pictus, Daucus glaber,
Crepis aculeata, Brassica tournefortii, and Cutandia philistaea, which are
considered characteristic of shifting dunes and semi-stabilized dunes, were most
abundant in the cleared plots. In the first year after removal of the vegetation,
Senecio joppensis (an annual endemic to the coastal dunes) was most abundant,
while by the third year, Rumex pictus was the dominant species. The high abundance in the cleared plot was related to the opening of the area and the exclusion of
shrubs that blocked out light. Similar trends were found for small mammals as was
found for the psammophilic annuals. The non-psammophilic field mouse
(Mus musculus) displayed a significant preference for the stabilized control plots
while the psammophilic gerbil (G. allenbyi) showed a distinct preference for the
treated open plots.
The experience gained at the Alexander Stream National Park was taken to
Nizzanim LTER Nature Reserve to test it as a possible management tool for conserving the high and characteristic biodiversity of coastal dunes. The woody vegetation, with Artemisia monosperma as the dominant shrub species, was uprooted
(partially from seven stabilized dunes and completely from another four stabilized
dunes) by a bulldozer in 2005. Preliminary results indicated that during the first 2
years after treatment, the sand on the manipulated dunes shifted significantly more
than it did on the non-manipulated dunes (Tsoar and Blumberg 2002). In addition,
psammophile species had begun to establish themselves on the manipulated dunes,
especially on those that were physically close to the non-manipulated, mobile and
semi-mobile dunes. For example, the fringe-fingered lizard (Acanthodactylus
scutellatus) was almost absent from stabilized and semi-stabilized dunes, but
appeared in relatively large numbers on one of the dunes after the partial removal of
the woody vegetation. This seems to be common only on manipulated dunes
located near natural, mobile dunes. However, the data collected and analyzed for
the next 3 years showed that there is a regression in the ‘‘psammophilic’’ trend and
the original species of the stabilized dunes are re-establishing themselves on the
manipulated dunes. The conclusion from this experiment is that while a slight shift
in the community composition toward the shifting sand stage took place, it was
insufficient (spatially and/or temporally) to allow recovery of the more specialized
psammophiles chosen as indicators. Four years after the woody vegetation removal,
the manipulated dunes are far from being similar to the mobile or semi-stabilized
dunes in terms of plant and animal assemblages. These dunes are different, but still
similar to the stabilized dunes (Figs. 11.4, 11.5).
There may be several reasons for the final results of this experiment:
(1) Scale and location—the vegetation was removed from a few dunes surrounded
by stabilized ones with vegetation coverage between 40 and 60 %. Additionally, the dunes from which the vegetation was partly removed are located about
2 km from the coast and about 1 km from the mobile dunes. Therefore, the sand
supply was low at the beginning and decreased shortly after to almost zero,
enabling the establishment of vast numbers of annual plants.
180
P. Bar (Kutiel)
Crepis aculeata, Brassica tournefortii, and Cutandia philistaea, which are
considered characteristic of shifting dunes and semi-stabilized dunes, were most
abundant in the cleared plots. In the first year after removal of the vegetation,
Senecio joppensis (an annual endemic to the coastal dunes) was most abundant,
while by the third year, Rumex pictus was the dominant species. The high abundance in the cleared plot was related to the opening of the area and the exclusion of
shrubs that blocked out light. Similar trends were found for small mammals as was
found for the psammophilic annuals. The non-psammophilic field mouse
(Mus musculus) displayed a significant preference for the stabilized control plots
while the psammophilic gerbil (G. allenbyi) showed a distinct preference for the
treated open plots.
The experience gained at the Alexander Stream National Park was taken to
Nizzanim LTER Nature Reserve to test it as a possible management tool for conserving the high and characteristic biodiversity of coastal dunes. The woody vegetation, with Artemisia monosperma as the dominant shrub species, was uprooted
(partially from seven stabilized dunes and completely from another four stabilized
dunes) by a bulldozer in 2005. Preliminary results indicated that during the first 2
years after treatment, the sand on the manipulated dunes shifted significantly more
than it did on the non-manipulated dunes (Tsoar and Blumberg 2002). In addition,
psammophile species had begun to establish themselves on the manipulated dunes,
especially on those that were physically close to the non-manipulated, mobile and
semi-mobile dunes. For example, the fringe-fingered lizard (Acanthodactylus
scutellatus) was almost absent from stabilized and semi-stabilized dunes, but
appeared in relatively large numbers on one of the dunes after the partial removal of
the woody vegetation. This seems to be common only on manipulated dunes
located near natural, mobile dunes. However, the data collected and analyzed for
the next 3 years showed that there is a regression in the ‘‘psammophilic’’ trend and
the original species of the stabilized dunes are re-establishing themselves on the
manipulated dunes. The conclusion from this experiment is that while a slight shift
in the community composition toward the shifting sand stage took place, it was
insufficient (spatially and/or temporally) to allow recovery of the more specialized
psammophiles chosen as indicators. Four years after the woody vegetation removal,
the manipulated dunes are far from being similar to the mobile or semi-stabilized
dunes in terms of plant and animal assemblages. These dunes are different, but still
similar to the stabilized dunes (Figs. 11.4, 11.5).
There may be several reasons for the final results of this experiment:
(1) Scale and location—the vegetation was removed from a few dunes surrounded
by stabilized ones with vegetation coverage between 40 and 60 %. Additionally, the dunes from which the vegetation was partly removed are located about
2 km from the coast and about 1 km from the mobile dunes. Therefore, the sand
supply was low at the beginning and decreased shortly after to almost zero,
enabling the establishment of vast numbers of annual plants.
180
P. Bar (Kutiel)