baumzaehlen - Primeval Forests & Their Trees

©2017copyright christoph hase

Tyresta National Park, Sweden

 

The park includes one of the largest sections of untouched forest in southern Sweden1. Of the total park area (20 km2) more than half may be regarded as primeval forest, mostly in the western part of the park2. The park is in the transitional zone (“hemiboreal” 3) between the temperate deciduous forests and the boreal forests but so close to the northern limit of the zone that the vegetation is overwhelmingly boreal in nature. A large proportion of the primeval forest is of low productivity – low open Opens internal link in current windowPinus sylvestris (Scots pine) forest on rocky terrain – a fact that has probably contributed to the preservation of the primeval forest next to the capital of Sweden. In the valleys, there are productive relatively tall stands dominated by Opens internal link in current windowPicea abies (Norway spruce). The other most common trees are also typical boreal species: Opens internal link in current windowBetula pendula (silver birch), Opens internal link in current windowB. pubescens (downy birch) and Opens internal link in current windowPopulus tremula (common aspen). Opens internal link in current windowAlnus glutinosa (black alder) is common on moist sites. Opens internal link in current windowQuercus robur (pedunculate oak), pointing to the temperate zone, can be found here and there. Tree species diversity is low and most species are easy to identify. Old P. sylvestris trees are plentiful, the oldest being more than 500 years old 1. In 1999, a wildfire burned around 4.5 km2 of forest in the central part of the park2.

 

The park is located at an elevation of approx. 20–80 metres. Annual precipitation is approx. 510 mm and average annual temperature 6.9°C. The park is surrounded by Tyresta Nature Reserve, which serves as a buffer zone for the park1. There are a lot of marked hiking trails. Off-trail hiking is quite easy, though there are some low cliffs and small bogs. Camping is only allowed at designated sites2.

 

References:

 

1       http://sverigesnationalparker.se

2       http://www.tyresta.se/

3       Hämet-Ahti, L., Palmén, A., Alanko, P. & Tigerstedt, P. M. A. (1992): Suomen puu- ja pensaskasvio. Dendrologian Seura.

 

Official sites:

 

http://www.tyresta.se/

 

http://sverigesnationalparker.se/en/choose-park---list/tyresta-national-park/#.VhfNaG6nlyo


Low Pinus sylvestris (Scots pine) forest at dry rocky site. Also Juniperus communis (common juniper, centre foreground) and Betula pendula (silver birch, right background).
Picea abies (Norway spruce) forest in moist valley. Also Pinus sylvestris (Scots pine, with coarse bark) and Betula pendula (silver birch, with white bark).
Bog with Betula pubescens (downy birch). Right foreground: small Pinus sylvestris (Scots pine) and Salix pentandra (bay willow).
Spruce mire with Picea abies (Norway spruce). Also Pinus sylvestris (Scots pine, with coarse bark) and Betula pubescens (downy birch).
Old Pinus sylvestris (Scots pine) on rocky site. Other trees: P. sylvestris with reddish trunks and Picea abies (Norway spruce) with dense foliage.
Two large Populus tremula (common aspen) on the left, the left one dead. Dead Pinus sylvestris (Scots pine), centre foreground; dead Picea abies (Norway spruce), right foreground; P. abies, other trees.
Quercus robur (pedunculate oak). Also Populus tremula (common aspen, foliage top right) and Picea abies (Norway spruce).
Alnus glutinosa (black alder) canopy.
Salix caprea (goat willow). Also Picea abies (Norway spruce) twigs.