Dabas parks Piejūra () is a nature park along the Gulf of Riga in Latvia founded in 1962. It is a protected nature reserve and a Natura 2000 location. The park stretches over an area from Riga, through Carnikava Municipality, and up to Saulkrasti. It is a popular seasonal recreation location, notably for beach access. The park is notable for its protected biotopes, particularly its dunes and boreal forests. The park's conservation plan for 2020 onwards was developed under the "LIFE CoHaBit" project.
Location
The nature park is a protected area designated as a nature reserve in Latvia, as well as a Natura 2000 territory. It is the third oldest nature park in Latvia. The park was formed primarily for the preservation of biotopes. A concrete goal is to further the coexistence of oligotrophic to mesotrophic plants in mineral-starved mesotrophic lakes and their coasts.
The area of the park is . The territory is located in Rīgavas līdzenums (Rigava plain) in :lv:Piejūras zemiene (Seaside lowland) coastal zone. The park stretches along the coast of the Gulf of Riga, with up to wide areas and occupies 7% of coastal zone in Latvia. The territory spans from Vakarbuļļi village North-West of Riga, through Carnikava Municipality, and up to Inčupe river South-West of Saulkrasti The park borders the Lielupe and Daugava river estuaries and includes of Gauja estuary.
The park is primarily owned by State (56%), municipalities (40%) and only 4% privately. There are few permanent residents in the area and most infrastructure is outside the area. The park is divided into 3 functional zones: nature reserve, nature park and neutral zones.
Geology
The to thick terrain consists of sand, aleurites and clay deposits, primarily from Baltic Ice Lake, Littorina Sea and its lagoons as well as alluvial river and delta sediments. Most of the territory is covered with around meter thick sand sediment with up to in dune ridges. The majority of territory's height ranges between with up to in the dune ridges. The newer West side is only high.
Ecology
80% of the park's area are forests, 10% are beaches and dunes, while only 2% are human infrastructure. The park contains 24 identified EU biotopes that make up 84% of the territory. The most common biotopes are forested coastal dunes (2180), fixed coastal "gray" dunes with herbaceous vegetation (2130) and old boreal forests (9010). Other less common biotopes and those of conservation interest are embryonic shifting dunes (2110), foredunes (2120), forested coastal dunes and old boreal forests, Northern boreal alluvial meadows (6450), and boreal Baltic coastal meadows (1630).
Many rare plant and animal species are found here. Plant species are mainly determined based on the park's sand bedrock, high groundwater levels and poor natural drainage. Many rare vascular plant species are found here. The park is one of the most notable bird migration routes in Europe. Various water birds and songbirds can be found here, including sightings of Eurasian eagle-owls and Sea eagles.
Forests
Forests occupy 72% or area of the park, and have a high cultural and ecosystem regulation value. Forests vary between new growths and old forests depending on soil and forestry practices. 80% of the forests are dry pine forests formed in dune ridges and hills. In many locations, dense pine stands had been planted to stop the now-dormant shifting dunes. There haven't been significant changes in forest biotope areas in recent years, although some of the "gray" dunes have becomes forested coastal dunes. These forests are most influenced by recreational and tourist anthropogenic effects – foot traffic, garbage disposal, bad forestry practices.
There are six EU and Latvia protected forest biotopes and forested coastal dunes account for 93% of park's forests. Other forest biotopes occupy relatively small areas and are old boreal forests, deciduous swamp woods (9080), bog woodland (91D0), alluvial forests (91E0), and herb-rich forests (9050).
Natural and planted forested coastal dunes take up a area and vary between compact dune groups to wide dune arrays as well wide inter-dune depressions, and can overlap with old boreal forests. These primarily pine and rarer spruce forests are mostly dry, with poor mineral, nutrient and water circulation. In interdune depressions, there are some mixed wet forests with a mixture of birch, black alder and pines. Latvia is one of the few EU countries that still has natural forested coastal dunes, particularly without transformation. The estimated biotope habitat quality of forests range between poor to excellent, with potential for poorer areas to improve with proper maintenance. About are old pine stands that closest match natural forests, some reaching 250 year age. These location have the highest species variety and most favourable conditions, although newer regions are nevertheless an important habitat. Various rare and endangered species are found here, such as Pulsatilla pratensis, Dianthus arenarius, Epipactis atrorubens, Platanthera bifolia, Lycopodium annotinum, and Lycopodium clavatum.
Dry soil old boreal forest and herb-rich forest biotopes can be found in Garciems lagoon and house many rare species. Forest variety is further supplemented by bog woodland and deciduous swamp woods that can be found in inter-dune depressions with wet mineral-rich soil, while alluvial forests grow near rivers.
Dunes and beaches
Three EU protected dune biotopes are found here – embryonic shifting dunes, foredunes and "gray" dunes. The dunes found in the park are a high-valued recreation, tourism and sport resource year-round, especially due to being near Latvia's most-populated areas. They are also an effective erosion-regulating barrier against sea effects. Overall, dunes are susceptible to anthropogenic and natural "mechanical" damage, invasive species, and eutrophication.
Embryonic dunes that form from washed out sand and high winds are rarely found on Latvia's coastline and are located in the park. The area of foredunes has been decreasing over the years likely due to anthropogenic effects and recreational beach improvement works that prevent new foredune formation even though the geological conditions are otherwise favourable, namely along Vakarbuļļi, Daugravgrīva and Vecāķi beaches.
Foredunes are often found along the beach over area and are home to littoral and psammophytic plant species. Many of foredunes have transformed or been reclassified into "gray" dunes over time, so their absolute area has decreased. No new foredunes are forming between Lielupe and Daugava, while new ones are forming around Lilaste.
"Gray" dunes are commonly found in the park and cover . These xerophytic dunes house a wude diversity of plant species and communities. It is the main habitat for rare plant species, such as Dianthus arenarius, Alyssum gmelinii, and Pulsatilla pratensis. The area classified as "gray" dunes has significantly increased over the years both from foredune conversion and more accurate classification, including the addition of open areas within the nearby forests. "Gray" dunes are also susceptible to overgrowing and becoming "brown" forested dunes.
There are two beach monitoring stations in the park – one in Daugavgrīva and one in Lilaste. In Daugavgrīva, embryonic dunes and "gray" dunes are only found in select areas, and new dunes do not form due to high human presence. In Lilaste, few embryonic dunes form due to human influence, however there is stable sand accumulation and foredune formation.
Among the EU and Latvia's protected biotopes are annual vegetation of drift lines (1210) and boreal Baltic sandy beaches with perennial vegetation (1640), both of which are very rare in Latvia and primarily located around The Gulf of Riga. The former is an important insect habitat and feeding grounds for waders. The rare biotope occupies near Lielupe estuary. The latter biotope is similarly very rare and takes up only . Although the biotopes are small areas by themselves, they add a significant recreational value and well as protect against the coastal wave and wind influence. Their continued protection mainly depends on minimizing human influence and allowing natural geological processes to take place.
Lakes
There are seven natural lakes in the park (excluding oxbow lakes) – , , , , Dziļcaurums, Serģis, and . The first of the six formed 4000 to 6000 years ago from the receding sea and are the only example of such formation in Latvia. All lakes are above sea level and are shallow ranging between in depth. All lakes are located in Gauja river's drainage basin, although Ummis, Ziemeļu Garezers, Dziļcaurums and Mazlandziņa are drainless lakes and are only located in the basin geographically. Vidējais Garezers and Serģis are draining open lakes, while Dienvidu Garezers is through-flowing. All lakes have almost fully-natural slow drainage basins, mostly forested with some bog areas.
Bogs
There are a few small bogs and one larger bog in the park - a large Serģu purvs. All bogs are dominated by natural processes with little human influence. Serģu bog formed when the Serģa lake was drained via ditches dug in 1906, and these ditches remain today. By the 1940s, the lake had overgrown and there is only area of shallow (<) open water at present. Serģu bog is mostly wet and swampy, with some edges overgrown with trees and bushes. Most of the bog is covered with reeds and various transitional bog plants. Most of Serģu bog territory is of a Latvia's protected transition mire and quaking bog (7140) biotope, while the rest is active raised bog (7110). The bog's conditions are ill-suited for the growth of any protected species, although protected Hammarbya paludosa has been found. Around of still-living tree area is expected to become bogland within some decades, meanwhile serving as a habitat for various species dependant on dead trees. Other small bogs formed in depression between dunes and around areas of Garezers lakes where they have overgrown with plants forming transitional and raised bogs, or simply overgrown wet areas. Overall, the bogs are not suited for recreation and are of limited economic value, although their presence adds to the overall variety of the park. The bogs do however provide important water cycle and oxygen regulation, habitat for a variety of bog-exclusive species, and a natural barrier to invasive species and forest fires.
Climate
The climate in the park is moderately warm and wet. There are lesser temperature fluctuations compared to the inland. The sea water accumulates warmth during summer and makes the autumn and winter warmer than inland. However, this also makes spring and summer cooler due to slower water warming. There are stronger winds in the park than inland, with coastal and sea breezes from interaction between water and land. The vegetation period is about 200 days, while the snow cover can remain up to 100 days a year.
History
The main terrain of the park formed during the 5–7 thousand years during and after the Littorina Sea period. The new Western area only formed 300–400 years due to construction of dams and piers around Daugava delta.