The Fiľakovo surround belongs to the Ipeľ-Rimava Trough flora district of the Paleo-Matra flora region (Matricum) within the Pannonian flora land (Pannonicum). The flora of this territory is rich, the recent knowledge contains data about occurrence of cca 1200 plant taxa in the Cerová vrchovina upland. Together with the neighbouring area in Hungary (/PLA/ Karancs-Medves Tajvédelmi körzet) the plant taxa number of wider surround is above 1300. Characteristic feature of the area vegetation is an intersection of mountain, psychrophile plant species and pannonian, strong thermophilic plant species. Some mountain species like Dentaria glandulosa, the Red elderberry (Sambucus racemosa) and Rowan (Sorbus aucuparia) occur in the north slopes and north oriented narrow valleys. Vice-versa, the south slopes are settled by termo- and xerophilic plant species in higher ratio, like the Bladder senna (Colutea arborescens), flax (Linum hirsutum) or grass Chrysopogon gryllus. Till it is known the occurrence of 35 protected plant species in the territory , 201 species belong to the red list.
To most often occurring forest biotopes (in Fiľakovo cadastre) belong the Turkey oak-sessile oak forests and Oak-hornbeam forests. There occur Asperulo-Fagetum and Luzulo-Fagetum beech forests and acidophilous oak forests in wider territory. On skeletal soils grow the Tilio-Acerion forests on slopes, screes and ravines, near streams - the mixed Ash-alder alluvial forests. Pannonian woods with Quercus pubescens occur rarely on sunny and skeletal slopes. A great part of the forests of the Cerová vrchovina upland is influenced by the occurrence of an alien woody plant false acacia (Robinia pseudoacacia). A small part of the forests is represented by introduced coniferous species, especially the Scotch pine (Pinus sylvestris).
The Turkey oak-sessile oak forests as light and dry forests are represented by dense coverage of the herbaceous etage, mainly the grass, often with the dominating Meadow grass (Poa nemoralis). The Rose Campion (Lychnis coronaria) is a typical protected plant of this plant society. The Field maple (Acer campestre) occurs often in tree etage, besides the dominating Turkey oak (Quercus cerris) and Sessile oak (Quercus petraea). In scrub etage we can find the Mayflower (Crataegus monogyna) and Common privet (Ligustrum vulgare).
The Oak-hornbeam forests occur in soft moist sites, in contrast to previous plant society, mainly on gentle slopes. Because of dense crown canopy of the Hornbeam (Carpinus betulus), the herbaceous layer is poor, often created only by the Carnation grass (Carex pilosa) or spring ephemeral plants like the Lesser celandine (Ficaria verna), Corydalys solida, Anemone ranunculoides and others. From the protected plant species we can present the Martagon Lily (Lilium martagon) and various species of Helleborines (Epipactis sp.).
Among of other forest biotopes, especially in higher locations or on north slopes (Medveš, Karanč, National Nature reserve Šomoška, Šiator, Pohanský hrad, Monica and others) we can find the Asperulo-Fagetum beech forests, which can change to the Luzulo-Fagetum beech forests on steep slopes. In this territory- in beech forests – Dentaria glandulosa - the Carpathian endemic species occurs rarely. Among of protected plant species of Orchidaceae family we can present the Red Helleborine (Cephalanthera rubra) at least.
The Bladder senna (Colutea arborescens) occurs mainly in the Pannonian woods with a sporadic occurrence of the Downy oak (Quercus pubescens).
From the natural science and protection point of view the Tilio-Acerion forests on slopes, screes and ravines and mixed ash-alder alluvial forests are meaningful. The debris forests are protecting forests mostly and according to highly skeletal soils, if you like their structure is more well-preserved. A great quantum of dead-wood occurs here too, these forests we find most often on top sites with rocks.
From the non-forest grass biotopes the significant part is created by xero-termophilic grass vestures (pastures), in minor ratio by mesophilic pastures and meadows. To typical and by law protected plants of xero-termophilic pastures and meadows belong the Pasqueflower (Pulsatilla grandis, Pulsatilla pratensis), the grass Chrysopogon gryllus, the flax Linum hirsutum subsp. glabrescens, the Lady orchid (Orchis purpurea), various Stipa species (Stipa sp.) and other. On mesophilic pastures in some localities the Orchis (Orchis morio) occurs numerously. Rock vegetation grows on basalt volcanism elements mainly. To its representatives we range the Houseleek (Sempervivum marmoreum), the Goldmoss Stonecrop (Sedum acre) and various species of finger-ferns (Asplenium sp.) The accumulation water reservoirs, built in the eighties of 20. century, are situated in wider territory. Some of the wetland biotopes are concentrated near by these reservoirs and on stream alluvial deposits. Among of rare and at the same time typical plants let us introduce the Flowering rush (Butomus umbellatus) and we have literary data about the Yellow water lily (Nuphar lutea).
There has been proved the occurrence of approx. 2500 zoological taxa in the wider territory (PLA Cerová vrchovina) till. 339 of them belong to protected animals and 337 are ranged in Red List. 184 species belong to protected animals of European significance.
The fauna of invertebrates is known particularly only and some species groups only. The knowledge about them are not entire, newest researches still bring new data about the occurrence of next species, which are meaningful from protection and faunistic point of view. As most meaningful taxa of the territory we consider species of international significance and species with the boundary of its extension in the observed area. In PLA Cerová vrchovina the Mediterranean and Pannonian species, rare in Slovakia, occur numerously.
Among of spiders (Aranea) we consider most meaningful the occurrence of Zora paralella, which is the only data about the occurrence of this species in Slovakia. The Wandering spider (Geolycosa vultuosa) has north extension boundary in the observed area, in Slovakia its occurrence is known from 3 localities only. In the territory the occurrence of 63 Orthoptera species was found out. Among of all we can present following species: the grasshoopers (Ruspolia nitidula, Tettigonia caudata) and Stetophymma grossum. Libelluloides macaronius is a meaningful mediterranean element of Neuroptera in the observed area. Among of beetles (Coleoptera) we consider the Stag Beetle (Lucanus cervus) and the Great Capricorn Beetle (Cerambyx cerdo) usual in the area and the Rosalia longicorn (Rosalia alpina) - rare species. These species are rare or extinct in majority of Europe yet. Among of butterflies in the observed area the Apollo (Parnassius apollo), Southern Festoon (Zerynthia polyxena) and medium abundant Large Copper (Lycaena dispar) are remarkable. To rarest species of day butterflies of xero-termophilic pastures with Sainfoin belong Cupido (Cupido osiris), in Slovakia known from 3 localities only, only from Cerová vrchovina upland known butterfly Polyommatus admetus and the Mediterranean element Provençal Short-tailed Blue (Everes alcetas). The strongest population of the Large Blue (Maculinea arion punctifera) in Slovakia occurs in Cerová vrchovina upland too.
Together with the fauna of water reservoirs the occurrence of 22 fish species (Osteichthyes) and 14 amphibian species is known from the Cerová vrchovina upland territory. To typical amphibian species if the territory we rank the common toad (Bufo bufo), European green toad (Bufo viridis), European tree frog (Hyla arborea), Common Spadefoot Toad (Pelobates fuscus) and Edible Frog (Rana esculenta). Among of reptiles the occurrence of 10 species is proved. European Green Lizard (Lacerta viridis), Sand Lizard (Lacerta agilis) and common wall lizard (Podarcis muralis) occurr largely in the observed area. The occurrence of the Smooth Snake (Coronella austriaca) and Aesculapian Snake (Elaphe longisima) is typical.
From the Vertebrata the Birds are the most common group by species in the observed area. The occurrence of 219 bird species is known till. To rare species nesting in old beechwoods we rank the Black Stork (Ciconia nigra), Ural Owl (Strix uralensis ) and White-backed Woodpecker (Dendrocopos leucotos). In oakwoods the nesting of Middle Spotted Woodpecker (Dendrocopos medius) and sporadically the Short-toed Treecreeper (Certhia brachydactyla) is typical. Among of rare birds of prey the data about the Short-toed Eagle (Circaetus gallicus) are known too in the area. On the present, the Hoopoe (Upupa epops), Barred Warbler (Sylvia nisoria), Red-backed Shrike (Lanius collurio) and Woodlark (Lullula arborea) are typical species in pastures with solitary trees and bushes. The Eurasian Eagle Owl (Bubo bubo) belongs to rare stone-pit nesting species. The European Bee-eater (Merops apiaster) nests in tunnels made in sand–pits and natural sandy banks. The Little Bittern (Ixobrychus minutus) and Eurasian Marsh-harrier (Circus aeruginosus) nest, beside other birds, in reed edged water reservoirs.
The occurrence of 59 mammalia species (Mammalia) is known in the observed area. A meaningful gene pool area of The European ground squirrel (Spermophilus citellus) in Slovakia is situated in the wider territory (Baštianska basin, Hostická basin). From the carnivorous animals, from the nature protection point of view, we can underline the occurrence of The European Otter (Lutra lutra) and Wildcat (Felis silvestris). The acknowledgement of the occurrence of the Mouse-eared bat (Myotis alcathoe) and Greater Noctule bat (Nyctalus lasiopterus) we consider meaningful faunistic data.