Združba je nastala z degradacijo (prekomernim izkoriščanjem) potencialno naravnih gozdov asociacije Abio albae-Carpinetum betuli. V teh gozdovih so prebivalci sekali les za kurjavo in gradbeništvo ter nabirali in kosili steljo. Združba se pojavlja na rahlo razgibanem gričevju in v ravninskem svetu na nadmorskih višinah med 150 in 300 m. Količina padavin je med 1100 in 1500 mm, povprečna letna temperatura pa je med 8 in 10° C. Tla so močno izprana.

Diagnostična kombinacija rastlinskih vrst
Drevesna plast: navadna breza (Betula pendula), trepetlika (Populus tremula).
Grmovna plast: Betula pendula, Carpinus betulus, Frangula alnus, Populus tremula, Salix caprea.
Zeliščna plast: Agrostis capillaris, Brachypodium rupestre, Carpinus betulus, Cornus sanguinea, Corylus avellana, Cruciata glabra, Festuca ovina agg., Lathyrus montanus, Luzula luzuloides, Melampyrum pratense, Molinia arundinacea, Potentilla erecta, Pteridium aquilinum, Quercus petraea.

Sestoji, v katerih je breza skoraj monodominantno drevo, so zelo presvetljeni. Les, ki je le skromnih dimenzij, je uporaben predvsem za kurjavo.

Vegetacija se je po opustitvi tradicionalnega gospodarjenja začela razvijati v smeri potencialno naravne vegetacije gabrovega gozda. Samo s tradicionalnim gospodarstvom bi lahko ohranili te brezove gozdove, ki so za območje značilni. Po vrstni sestavi so gozdovi razmeroma skromni in z biološkega gledišča niso posebej zanimivi. Večji pa je njihov krajinski pomen.

Združbo navadne breze in orlove praproti uvrščamo v zvezo Quercion roboris-petraeae.

The secondary association Pteridio–Betuletum is a result of the degradation of potentially natural forests of the association Abio albae–Carpinetum betuli. The wood in these forests has been used for fuel and building purposes by local people, and litter has also been collected from these forests. The association occurs on hills with a gentle natural configuration and in lowlands at an altitude between 150 and 300 meters. The annual rainfall amounts to between 1,100 and 1,500 mm, and the annual average temperature is between 8 to 10^o C. The soils are very leached chromic Luvisols.

Diagnostic combination of plant species
Tree layer: Betula pendula, Populus tremula.
Shrub layer: Betula pendula, Carpinus betulus, Frangula alnus, Populus tremula, Salix caprea.
Herb layer: Agrostis capillaris, Brachypodium rupestre, Carpinus betulus, Cornus sanguinea, Corylus avellana, Cruciata glabra, Festuca ovina agg., Lathyrus montanus, Luzula luzuloides, Melampyrum pratense, Molinia arundinacea, Potentilla erecta, Pteridium aquilinum, Quercus petraea.

The stands where birch plays a nearly monodominant role are relatively well lit. The wood of modest dimensions is used mainly for fuel.

The vegetation began to develop in the direction of potentially natural vegetation of the forests of the Abio albae–Carpinetum betuli after traditional farming practices had been abandoned. The birch forests that are characteristic of the area can only be preserved through traditional farming practices. These forests are relatively modest with regard to their species structure and are not of great interest from the biological point of view. They assume an important role in the appearance of the landscape.

The Pteridio–Betuletum is classified in the alliance Quercion roboris–petraeae.

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Čarni A. & A. Seliškar 1994: Vegetacija. V: M. Accetto & al.: Raziskave flore, vegetacije in favne na območju krajinskega in regijskega parka ob reki Kolpi. Biološki inštitut. 41 s.