The ancient plain landscape (based on the native forest of the Po valley) was characterized by the presence of swampy areas interrupted by large emerged areas occupied by forests of white oak, black and white poplar, black and white hornbeam, field maple and thick undergrowth.
The landscape context in which the Reserve is inserted, like the whole Po Valley, derives from centuries of deep changes.
The outer areas of the Reserve are destined for agricultural use, mainly simple arable land and fruit-growing plants, confining the growth of spontaneous vegetation to a few edges located at the borders of these cultivated areas.
Going inside the area, the presence of the basins for the collection of flood waters, the islets, the embankments and the river itself determine a marked diversity of environments which is reflected in a significant variety both of the vegetational and the faunal components.
The main vegetable formations present within the Reserva are mainly hygrophilous such as the rushes, consisting of Phragmites australis and Typha latifoglia and the hygrophilous wood, typical of wetlands and consisting mainly of white willows (Salix alba), poplars (Popolus alba and Popolus nigra), and, in its more consolidated portions, of alders (Alnus glutinosa), white hornbeams (Carpinus betulus) and common hoaks (Quercus robur).
In its undergrowth, the hygrophilous forest is composed of all those species that also make up the shrubby mantle inside the Reserve: the hawthorn (Crataegusmonogyna), the blackthorn (Prunus spinosa), the elderberry (Sambucus nigra), the spindle (Euonymus europaeus), the common dogwood (Cornus sanguinea) and the red willow (Salix purpurea) in the most humid parts.
The mammalian class is represented primarily by medium-sized carnivores such as the fox (Vulpes vulpes), the badger (Meles meles), the beech marten (Martes foina) and the weasel (Mustela nivalis), almost all of which are nocturnal and difficult to observe.
The largest number of mammals is however attributable to the microfauna present in the Reserve, to which belong the common shrew (Sorex araneus), the water shrew (Neomys fodiens), the pygmy shrew (Sorex minutus), the lesser white-toothed shrew (Crocidura suaveolens), the white-bellied shrew (Crocidura leucodon), the Etruscan shrew (Suncus etruscus), the field vole (Arvicola terrestris), the Savi's pine vole (Microtus savii), the common vole (Microtus arvalis) and the European pine vole (Microtus subterraneus).The presence of the most common species such as the European mole (Talpa europaea), the hare (Lepus euro-paeus), the European hedgehog (Erinaceus europaeus), the wild mouse (Apodemus sylvaticus), the dormouse (Glis glis), the Etruscan shrew (Moscardinus avellanarius), the brown rat (Rattus norvegicus) and the nutria (Myocastor corpus) which in a few years has colonized most of the watercourses of the plain including the expansion tanks of the Secchia.
Finally, there is also the order of the Chiroptera most commonly called bats, present with the Kuhl's pipistrelle (Pipistrellus kuhli), the common pipistrelle (Pipistrellus pipistrellus), the serotine bat (Eptesicus serotinus) and the greater mouse-eared bat (Myotis myotis).
The rural lizard (Podarcis sicula), the lizard (Podorcis muralis) and the green lizard (Lacerta viridis) are extremely common in the Reserve while the blindworm (Angiuis fragilis), although a common species and adapted to various environments, has been estimated scarcely heavy.
The blindworm, the green lizard and the other saurians have a bitter enemy: the white snake (Coluber viridiflavus) which is also common both inside the expansion tank and in most of the environments present, from the plain to the mountain. Among its usual preys is also the viper (Vipera aspis), which however is not present in the protected area. The green whip snake, while appearing among the non-poisonous species, is one of the largest and most aggressive European snakes.
Other reptiles found inside the expansion area are: the Aesculapian snake (Elaphe longissima) with a small number of specimens, the grass snake (Natrix natrix), and the dice snake (Natrix tassellata). Very common is the European marsh tortoise (Emys orbicularis) unique, autochthonous and rare species of its family estimated in numerical decrease both in this environment and in many of the different sites of the plain and the hill where it was observed in the past. It is also conceivable that the exotic tortoises Trachemys scripta and Trachemys scripta elegans are present within the expansion area, following inputs by private and unauthorized parties from the consortium.
Over the years, the expansion area has become the habitat of various species of Amphibians Anuri (toads and frogs) and Urodeli (salamanders and newts). Of the first group there are six species including two types of toads, the most common of which is the emerald toad (Bufo virdis). Among the "red" frogs, the only representative surveyed with a limited number of specimens is the agile frog (Rana dalmatina), which owes its name to the agility with which it manages to escape predators. Among the "green" frogs, the minor green frog (Rana esculenta complex) is the most widespread both inside the expansion area and in the lowland wetlands.
Also belonging to this group is the bullfrog (Rana catesbeiana), an American species introduced in the past for food purposes (its weight can reach 1600 grams), so well adapted to our environments that it even became a threat to native species. Extremely voracious, it feeds on arthropods, micromammals, amphibians (even of its own species), reptiles, fish and more sporadically birds.
The birdlife is the most significant and macroscopic aspect of the reserve. Due to its location, the large amount of water, the simultaneous proximity of woods and the great variety of habitats, there are many species that could be observed. By taking advantage of the huts and observation points set up inside the reserve, you could get to know the habits of the most characteristic species.
The large water basins host the mallard (Anas Platyrhynchos), the Eurasian teal (Anas crecca), the garganey (Anas querquedula), the coot (Fulica atra), the common pochard (Aythya ferina), the tufted duck (Aythya fuligula), the common moorhen (Gallinula chloropus), the loon (Gavia spp.), the northern shoveler (Anas clipeata), the water rail (Rallus aquaticus), the great cormorant (Phalacrocorax carbo), the little grebe (Tachybaptus ruficollis), and the common snipe (Gallinago gallinago).
In open lakes you could observe the extravagant courtship of the great crested grebe (Podiceps cristatus) and also admire the large heronies, with the nests of grey herons (Ardea cinerea) and little egrets (Egretta garzetta), as well as the while elder heron (Egretta alba) and the night heron (Nycticorax nycticorax). Among the banks of the basins and in particular in the reeds there are the bittern (Botaurus stellaris) and the little bittern (Ixobrychus minutus), the red heron (Ardea alba), the great reed warbler (Acrocephalus arundinaceus) and the Eurasian reed warbler (Acrocephalus scirpaceus).
During the cold season it is easy to observe the common gull (Larus ridibundus) and the Mediterranean herring gull (Larus cachinnans) hovering above the area, while in spring it is equally easy to observe the terns (Sterna hirundo), an important and significant presence inside the Reserve, which nests on artificial platforms positioned inside the basins on in the gravel embankments of the river bed.
In the embankments and in the banks, there are some of the most spectacular birds of the European bird life, such as the kingfisher (Alcedo atthis) and the colourful bee-eater (Merops apiaster), the sand martin (Riparia riparia) and the white wagtail (Motacilla alba).
The hygrophilous wood offers hospitality to numerous species of birds including the great spotted woodpecker (Picoides major) and the green woodpecker (Picus viridis), the nuthatch (Sitta europaea), the robin (Erithacus rubecula), the great tit (Parus major), the blackcap (Sylvia atricapilla), the dunnock (Prunella modularis), the common chiffchaff (Philloscopus collibita), the willow warbler (Philloscopus trichilus), the Eurasian wren (Troglodytes troglodytes), the red-backed shrike (Lanius collirius), the Cetti's warbler (Cettia cetti), the Eurasian golden oriole (Oriolus oriolus), the common cuckoo (Cuculus canorus), the turtle dove (Streptopelia turtur), the blackbird (Turdus merula), the jay (Garrulus glandaris) and the magpie (Pica pica).
Among the birds of prey in the protected area, the kestrel (Falco tinnunculus) and the sparrowhawk (Accipiter nisus) are considered to be nesting, while the buzzard (Buteo buteo), the harrier (Cicus cyaneus), the red-footed falcon (Falco vespertinum) and the merlin (Falco columbarius).
It is also possible to observe with a little luck the rare marsh harrier (Circus aeruginosus), and the osprey (Pandion haliaetus) circling above the lakes. Among the nocturnal birds of prey there are the long-eared owl (Asio otus), the owl (Athene noctua), the scops owl (Otus scops) and the barn owl (Tyto alba).
The fish species currently present in the waters of the Reserve can be divided, according to their origin, into two groups: the most numerous is that of native species, that is to say originating from the aquatic environments of the Modena plain, while the second includes the non-native species, coming from other geographical areas in the Modena and Reggio areas.
The environmental transformations (above all the reduction of the extension and the worsening of the quality of the water environments) have penalized the biological needs of the native fishes, this is the case of the pike (Exos lucius), of the eel (Anguilla anguilla) and of the twait shad (Alosa fallax).
Protecting territories such as the Oriented Natural Reserve "Cassa di espansione del Secchia", in which insects have not been decimated by agricultural or industrial activities, means allowing the survival of many species of birds and other vertebrates. The importance of insects is essentially expressed in their contribution to plant reproduction (entomophilous pollination is the predominant one in higher plants) and in the fundamental role played in the food chain.
In Italy there are dozens and tens of thousands of insect species, so it is very difficult to make a complete census of the entomofauna, even in a restricted and easily investigable territory such as the Reserve. However, some interesting results have been obtained from a first survey promoted by the management body: the main orders are present in the territory examined, with a certain predominance of: Hemiptera, Diptera, Hymenoptera, Coleoptera and Lepidoptera.