# Dinaric calcareous block fir forest

The dinaric calcareous silver fir forests are an endemic vegetation type of the littoral Dinaric Alps, located in the Dinaric Mountains mixed forests ecoregion in Southeastern Europe. Pure stands of dinaric calcareous silver fir (Abies alba) forests appear on limestone escarpments in the montane zones of Orjen, Velebit, Biokovo and Prenj. As an endemic and rare vegetation type of the Dinarides, they need protection.

## Structure

Dinaric calcareous silver fir forests have an open structure which is environmentally sensible. As storms of bora and scirocco type are common in the coastal dinaric mountains, wind plays a great role in the formation of the highly labile structure in the pure silver fir communities. Silver firs can reach up to 35 metres (115 ft) on limestone and trunk diameters of 1 metre (3.3 ft) have been observed.

## Distribution

Dinaric calcareous silver fir forests are dispersed in smaller patches on the hyperkarstic littoral karst mountain environments of the Dinarides. Prominent are those on Velebit and Orjen, appearing on bare limestone escarpments in the montane lifezone between 1,200–1,550 metres (3,940–5,090 ft). The abundance of precipitation on these coastal mountains of up to 5000 mm/m$^2$a with the dry soil conditions restricts these pure silver fir forests to the most rainy and humid spots of the Dinarides.

## Ecology

Silver fir is a constituent of montane central European forests. As a rare species in dry climates of the Mediterranean, the silver firs presence on Mt. Orjen are restricted to humid northern slopes. A marked difference in the fir's vegetation patterns is seen here. It has a common cause in soil formation. High soil-water content in terrae fuscae on glacial superstratum leads to beech-fir forests, whereas dry initial rendzinas on glacio-karstic substrate support xeric dinaric calcareous silver fir forests. The latter endemic community rich in submediterranean species has evolutionary parallels with Bosnian Pine communities.

## Floristic composition

Dinaric calcareous silver fir forests are among the most species-rich montane ecosystems in the Dinaric Alps.
Mixed deciduous-silver fir peony (Paeonia daurica Andrews)-forests with Paeonia daurica' have the most species rich composition found so far on Orjen (Abies alba, Corylus colurna, Fraxinus excelsior, Fagus sylvatica, Acer intermedium, Tilia cordata, Acer pseudoplatanus, Pinus heldreichii).
* Syntaxonomic chart of mixed deciduous-silver fir-peony forest at Orjen

### Plant list

Typical plants of the many times dry basic Kalkomelasol soil plant Biotope: C. OREOHERZOGIO-ABIETALIA Fuk. 1969 a) O r e o h e r z o g i o-A b i e t i o n Ht. emend. Fuk. 1. Oreoherzogio-Abietetum Fuk.
| · 1. Trees Abies alba Pinus heldreichii Fagus sylvatica Corylus colurna Ostrya carpinifolia Pinus nigra Fraxinus excelsior · 2. Shrubs Berberis illyrica Lonicera glutinosa Viburnum maculatum Rhamnus fallax Sorbus aria Euonymus europaeus Rosa pendulina Juniperus nana Sambucus nigra Cotoneaster integerrimus Daphne mezereum Lonicera xylosteum Frangula rupestris · 3. Ground level Calamagrostis varia Lilium martagon subsp. cattaniae  Fritillaria gracilis Cirsium erisithales Valeriana montana Scrophularia nodosa Scrophularia bosniaca Polygonatum viviparum Cystopteris fragilis Arabis turrita Actaea spicata Astrantia major Viola riviniana Vicia cracca Arabis hirsuta Cardamine glauca Urtica dioica Paeonia daurica Muscari botryoides Satureja montana Seseli globuliferum Iberis sempervirens Myosotis sylvestris Taraxacum officinalis Aposeris foetida Hypericum alpinum Doronicum columnae | Epilobium montanum Ononis natrix Melica nutans Corydalis ochroleuca Ceterach officinarum Sedum boloniense Cicerbita alpina Erysimum humile Stellaria graminea Verbascum spec. Lotus alpinus Saxifraga marginata Symphytum tuberosum Asplenium trichomanes Hieracium murorum Convallaria majalis Actaea spicata Rubus idaeus Thalictrum aquilegiifolium Thalictrum minima Potentilla speciosa Potentilla argentea Myrrhis odorata Scilla litardieri Sesleria robusta Peucedanum longifolium Gentiana lutea Lamium spec. Agrimonia agrimonoides Polystichum lonchitis Achillea spec. Origanum vulgare Lotus corniculatus Heracleum sphondylium Gentiana verna Luzula luzuloides Silene spec. Sedum maximum Aquilegia dinarica Moltkia petraea Asphodelus albus Asplenium ruta-muraria Asplenium adiantum-nigrum Amphoricarpos neumayerii Ornithogalum umbellatum Epilobium angustifolium Biscutella cichorifolia |
| (around 50 Samples in Orjen) |