Hydro-ecological relations in the Delta Waters

Of course. tke environmental changes have not only influenced the
vegetatian but also the fauna. Figure 5 gives an idea of the dynamics
of the breeding bird populations on pne of the newly emergod islands in
Lake Grevelingen. &er the constmction of the dam in the
Broursershaveuse Gat some 400 hectares of tidal flats and a wll salt
marsh were exposed to the air and wind. &specially the species of sandy
beaches and pebble coasts (We the Kentish Plover) began to breed on
the new land. The population of Bedshank, also a coastal bird, did not
increase before some vegetation was existing. airily because the h-
needed this vegetation to hide their nests. At that time the species of
bare beaches were alrea* deelinhlg. The fimt breeding birds of shrlibs
have colonized the island only recently and a common species like the
Villow Warbler is still increasing. Woodland species do not breed on
the island, because vegetation structure has not yet been
dfiferentiated enough and there are no nestiag sites for these birds.
It will take at least some 50-1Wl years before the bird communities
begin to stabilfae.
G-rally
speaking the foll4ng factors influence the developnent of
vegetation and animal wildlLfe an the former dt marshes and tidal
f late :
* the initial ecosystem present at the moment of dw constrnctiod;
* processes of adaption ta the newly created situation;
* mahagement of water and Land by m=.
3.1 Initial ecosystems
The newly developed ecosystems have their starting point in the old
estuadne waters. These Mtial ecosystems are strongly influcn-d by
the origins1 waterrepime. This Fs illustrated by the distribution of
the vegetation series qf Figure l in relation to height and tidal
floo6ing (see Fig. 6). p e vegetation types inasated hy an open
rectangle died within rwo or three years &ter embanlaaent was finished