General features of Riihimäki's nature

In Riihimäki, the relative proximity of the sea moderates the winter (January -7 °C), but on the other hand, the influence of the Tammela highlands cools the summer (July +16 °C). The length of the thermal growing season has increased between 1996 and 2006 by more than 180 days, and the sum of the effective temperature, correspondingly, is close to 1 degrees. The annual rainfall in Riihimäki is about 400 mm on average, and there are about 610 rainy days a year. Permanent snow cover falls on Riihimäki on average on December 110, and snow accumulates in March on average 15–30 cm.

In terms of vegetation, Riihimäki belongs to the southwestern part of the southern boreal zone, the anemone zone. Like the rest of Etelä Häme, the southwestern influence in the flora is clear, for example white anemone and blue anemone are common. South-western burdock root is common, while south-eastern rose grass is rare in Riihimäki.

Of the forests, spruce-dominant, grove-like fabrics are the most common, but forests can be found from barren fabrics to lush groves. There are plenty of linden groves and even walnut bushes. Groves account for more than 30 percent of the forest land in Riihimäki.

Noteworthy grove plants in Riihimäki include eagle's wing, white and blue anemone, milkweed, grove violet, blackberry, wolfberry, tesma, dog wheat and rare rabbit lettuce.

You can also find interesting species in Kangasmets. Vanamo is beautiful for its leaves and the beautiful pink flowers are the nobility of the flower world. A common, but small-sized and hard-to-notice orchid, the nightshade is a great find in a moss-covered spruce. And even in autumn, you can find parasitic plants without green leaves, pine flowers, in the pine. Especially in old spruces, you can find knots or knots on the branches. Heathers, lingonberries and reindeer lichens delight the traveler on the otherwise barren pine cliffs. On the slopes of the ridges, you can notice the rare cat's paw and a slightly more lush slope, which smells fragrant at night. The end of forest grazing has reduced the places where light-demanding white groves grow.

An interesting feature of Riihimäki's bedrock is the widespread occurrence of a rare dark and alkaline rock type, gabbro, in the southern parts of the municipality. Many of Riihimäki's forested rocks consist of gabbro: for example, the Salmenkalliot on the north shore of Suolijärvi, the gorge walls of Paalijärvi canyon, Mikkolankallio and Kippakallio. There is metavolcanite at the edges of the gabbro zone. In the central part of Riihimäki, the most common type of stone is granite, and in the northern part, mica gneiss. The largest areas of rock close to the ground are located on the northeast side of Suolijärvi.

There is a clear northwest-southeast oriented longitudinal ridge in the western parts of Riihimäki and a similar one in the east on the Hausjärvi side. Between these there are shorter ridge sections heading north from Salpausela. Salpausselkä runs from the southeast side of Riihimäki via Hyvinkää towards Hanko. Riihimäki's soil mainly consists of clay dotted with moraine ridges as far as the subsoil is concerned. The surface soil mainly consists of clay, silt and loam.

Landscape-wise, Riihimäki belongs to Häme's farming and lake country. The western side of the city belongs to the upland region of Tammela and the eastern side to the farming and lake region of Keski-Häme.

On Riihimäki, the relative height variation is 30–75 meters and the area is hilly in nature. The highest point is Hatlamminmäki, which is 165 meters above sea level.

There are hardly any traditional biotopes in Riihimäki. However, along the rivers and ditches, there are sometimes unkempt and overgrown wet grass meadows. However, meadow plants can be found in Riihimäki on roadsides and forest edges, as well as on old cart paths. Noteworthy meadow plants in Riihimäki are, among other things, sedge leaves, sedge, honey berry, sedge, aholeinik, rose grass, daisy, burdock root, cat's bell and rare sedge grass.

Riihimäki has more swamps than usual for conditions in southern Finland, almost 10 percent, and they are versatile in terms of swamp types and sizes. The zone of prevailing swamp association types in Riihimäki are shield oases. However, the main part of the bog belongs to the vietto oasis and only the big Silmäkeneva belongs to the shield oasis. Among the types of marshes in Riihimäki, there are a variety of sedges and ravens, as well as sedges. Drainage has turned many bogs into bogs or bogs.

Hatlamminsuo, in the northeastern corner of the city, has been preserved as the most natural, which is designated as a nature reserve in the provincial plan and has already been mostly reclaimed for the state. Sammalistonsuo in the northern part of the city is a peat production area and an important bird area. To the south of the eye-catching agglomeration is a large drained swamp area.

Noteworthy bog plants in Riihimäki are, among others, marsh sedge, marsh flower, round-leaved sedge, common birch, common sedge, mud sedge and sedge, star sedge and rare white-striped grasses and sedge.

Riihimäki is characterized by the scarcity of water bodies. The total area of ​​Riihimäki is 126 km², of which 121 km² is land and 5 km² is water. Riihimäki's five lakes are all located in the southwest part of the city. There are no other surface waters of at least two hectares in size on Riihimäki. There are a dozen ponds smaller than this one. Some of them are natural ponds in forest and swamp environments, some are dug or dammed pools. Vantaanjoki flows in the Riihimäki area for about 13 kilometers. Herajoki and Paalijoki are tributaries of Vantaanjoki. In the north, the Riihiviidanoja, which belongs to the Kokemäenjoki catchment area, flows into Punkanjoki and further along Puujoki to the north.

Noteworthy beach plants in Riihimäki include, for example, beach and sedge, beach flower, sedge and bottle sedge, reed sedge, sedge sedge, broad-leaved osmankäimi and beach grass.