Biological characteristics

Plant cover by zoning unit

Although land cover is agricultural in its majority in the whole Biosphere Reserve, its weight varies depending on the zoning unit where we are. So as we can see how in the core area natural habitats are the majority, with the continental wetlands as the most represented cover. In contrast, in buffer and transition zones, the coverage of agricultural land and dry bushes are the most extensive.

The Biosphere Reserve Terras do Miño has a core area that exceeds 35,500 ha (7.9% of the area) whose major cover are continental wetlands, traditional agricultural mosaic and natural forests. These three categories of occupation account for 81% of this core area. On their own, the wetlands now account for 37% of the Reserve core, very high values that are justified when considering that the Reserve contacts 221 of the wetlands included in the First Galician Inventory. Within this group of wetlands, the different complexes present in peat bogs and northern mountains are notable for their length, and small wetlands near the rivers Parga, Ladra and Guisande for their number.

Regardless of the importance of wetland coverage within the core of the Biosphere Reserve, it is outstanding the diversity of types of wetland, recognizing up to 11 categories of Ramsar classification, three types of artificial wetlands and 8 types of natural continental wetland, highlighting its rarity in the context of regional karst systems (Zk) such that the one that originated the lagoon of Fonmiñá.

Tipología de humedales Ramsar. Terras do miño
Humedales continentales
(M) Ríos permanentes
(O) Lagos permanentes de agua dulce
(Tp) Pantanos / estuarios / charcas permanentes de agua dulce
(Ts) Pantanos / estuarios / charcas estacionales o intermitentes de agua dulce sobre suelos inorgánicos
(U) Turberas no arboladas
(W) Pantanos con vegetación arbustiva
(Xf) Humedales boscosos de agua dulce
(Zk) Sistemas Kársticos
Humedales artificiales
(2) Estanques artificiales
(6) Áreas de almacenamiento de agua
(7) Excavaciones

Fuente: IBADER

Instituto de Biodiversidade Agraria e Desenvolvemento Rural

GI-TB Territorio - Biodiversidade

Other noteworthy covers in the Reserve core corresponds to the natural forests in which, given the characteristics of the basin of the Upper Miño, it is important to differentiate between the wet and dry forests. The Ramsar classification of wetlands includes, within the freshwater tree wetlands swampy forests, seasonally flooded forests and tree swamps on inorganic soil. This way, just as in the classification Corine-Biotopes, the separation between this type of ecosystems against the forested peat (XP) is kept. Almost all of the forested wetlands of fresh water available in the Upper Miño correspond to humid forests developed on flood plains. Floodplain is a term used by Ramsar to describe wetlands, usually of great length, which may include one or more types of wetlands. In the Reserve Terras do Miño, the existence of flood plains of some superficial entity is limited to peripheral and central units, corresponding to wide fluvial valley bottoms or, in its majority, old valleys from the sedimentary valleys formed in the Cenozoic.

Mining, despite being the type of cover with lower representation of all that were differentiated, is remarkable for finding within the core zone mining in the open. Such activities have an occupation of approximately 107 ha within the core of the Reserve Terras do Miño, located in Riocaldo, landscape of the county of Begonte, and that presents an intense mining activity specialized in the extraction of aggregates deposited in the vicinity of the confluence of the rivers Parga and Ladra. These mines are partially included in the SCI Parga-Ladra-Támoga (ES112003).

Both in the buffer and traditional zones, the largest class of cover corresponds to the agricultural landscape. As in most European landscapes, ecosystems and communities are the result of the interaction between man and the environment. In these landscapes, the degree of human intervention is such, that it determines the nature of many of their habitats and therefore the survival of their characteristic species (Krywinski, 2007). Within the general concept of cultural landscapes, there is a clear distinction between those agricultural landscapes which are more intensive or industrial, and those where ancient sustainable practices remain. These are given the name of traditional agricultural landscapes, and often contain a rich biological diversity and greater heterogeneity with respect to other with more human presence (Duelli 1997; Luoto et al., 2003).

For the purposes of its implications in biodiversity and in a historical context, the term "traditional" is normally used to refer to the situation prior to the profound changes resulting from modernization and industrialization of agricultural activity.

The traditional agricultural landscapes are characterized by the following aspects (Antrop 1997, Calvo Iglesias, 2005):

  • The composition, configuration and functions of agricultural ecosystems
  • The traditional management techniques (farming and cultivation techniques)
  • The structural elements (walls, terraces, hedges)
  • The characteristic patterns of settlements and infrastructure
  • Other ethnographic elements such as micro-toponymy and oral traditions.

Generally, the cultural traditional agricultural landscapes are characterised by a full use of the territory, along with extensive agricultural uses and low contribution of nutrients or of more intensive nature. In both cases, a low level of technological resources and low production efficiency and cost. While its economic profitability is generally limited, from an environmental point of view, they acquire a great importance since they bring together habitats and ecosystems of conservation importance, as well as for her role in the conservation of genetic diversity of crop species. They are also systems with high ecological sustainability, demanding relatively few contributions of material and energy and presenting a high efficiency in their use and recycling, thus generating little waste (Bignal crack and Mc, 1996).

Despite the changes occurred in the Galician countryside, especially from the 60s of last century, the rural areas of Biosphere Reserves studied still contain a high diversity of traditional agricultural landscapes, either as a result of its position as the biogeographic history of their terrestrial ecosystems and the process of culturalization of its landscapes. This diversity is embodied in the existence of different agricultural structures and a diversity in composition and configuration of space farming as a result of adaptation to different environmental and historical-cultural contexts. The local scales show the added richness of its diverse ethnic heritage (fences, houses, barns...) and human settlements (Calvo Iglesias, 2005).

In the Biosphere Reserve Terras do Miño different types of agricultural landscapes are represented, noting in particular the traditional landscapes of enclosed fields (bocage) and landscapes of agra. The bocage area of the Northern Mountains is characterized by a dispersed habitat with small population entities and a partner framework in closed blocks, delimiting the plots with walls, hedges of grey willow (Salix atrocinerea) or scrub species (the genera Cytisus, Genista and Ulex) and/or fences. Currently, this landscape, although in many cases preserved their spatial configuration and associated agro-ecosystems, is threatened by demographic ageing, the abandonment of agricultural activity and the introduction of wind farms (Calvo Iglesias et al 2007a).

The agricultural landscape of agras was until very recent times the most widespread throughout Galician valleys. The name of agra refers to a block of land cultivated with an external closure, and divided inside in open plots. Previously, agras were ruled by a system of exploitation community, which implied the regulation of sowing and harvesting, types of cultivation carried out inside and limited access of cattle to graze the stubble. At present, the functionality of agras has virtually disappeared but their place names are still frequent and even the maintenance of spatial organization in areas that have not been restructured by the partner or urbanized merge or (Calvo Iglesias et al 2007b).

In the buffer zones, the agricultural landscape has a relative lower weight than in the transition zone, since it shares ownership with dry scrubland and rocky environments (especially in the perimeter mountain ranges) and forest formations, usually oak. These three units, along with masses of natural running water constitute the coverage of higher interest for the conservation, and account for 72% of the area of the buffer zones. However, the 33,447 ha occupied by the mosaic that defines the agricultural landscape (42% of the buffer zones) clearly stand out compared to other units.

In the transition zone, the dominance of agrarian landscape is even clearer reaching 64% of the area of the zonal category (159,393 ha). Nevertheless, the occupation of the artificial coverage is concentrated in this transition zone which includes 1,603 ha of infrastructure and urban and industrial areas and 320 ha occupied by open mining. It is also in the buffer zone, where most of the forest plantations with exotic fast- growing species are found (Pinus pinaster, P. radiate and, to a lesser extent, Eucalyptus spp.) that exceed 21,000 ha of buffer zones, which is equivalent to more than 8% of the category.

Usos del Territorio. Zona Núcleo Terras do Miño
Categoría
Superficie (Ha)
%
Humedales 13.117,85 36,95
Paisaje agrícola
10.761,50 30,31
Bosques 4.856,25 13,68
Pinares 3.312,25 9,33
Matorrales y berrocales
1507,50 4,25
Eucaliptales 1.232,75 3,47
Masas de agua corriente (Embalses y ríos)
307,00 0,86
Mezcla de Eucaliptos, pinos y frondosas autóctonas
192,25 0,54
Infraestructuras y áreas urbanas e industriales
107,50 0,30
Explotaciones mineras
107,50 0,30
Total Zona Núcleo
35.501,85 100

Usos del Territorio. Zona Tampón Terras do Miño
Categoría
Superficie (Ha)
%
Paisaje agrícola 33.447,25 41,82
Matorrales y berrocales
15.849,75 19,82
Pinares 11.461,25 14,33
Bosques 8.034,50 10,05
Humedales
5.798,29 7,25
Mezcla de Eucaliptos, pinos y frondosas autóctonas 3.974,25 4,97
Eucaliptales
1.036,00 1,30
Infraestructuras y áreas urbanas e industriales
224,00 0,28
Explotaciones mineras
123,00 0,15
Masas de agua corriente (Embalses y ríos)
36,25 0,05
Total Zona Tampón
79.984,54 100

Usos del Territorio. Zona Transición Terras do Miño
Categoría
Superficie (Ha)
%
Paisaje agrícola 159.393,50 64,20
Matorrales y berrocales
26.860,50 10,80
Mezcla de Eucaliptos, pinos y frondosas autóctonas 23.064,00 9,29
Pinares 19.715,00 7,94
Bosques
14.672,59 5,91
Infraestructuras y áreas urbanas e industriales 1.603,00 0,65
Eucaliptales
1.473,50 0,59
Humedales
1.132,50 0,46
Explotaciones mineras
319,75 0,13
Masas de agua corriente (Embalses y ríos)
28,00 0,01
Total Zona Transición
248.262,34 100

Fuente: IBADER

Instituto de Biodiversidade Agraria e Desenvolvemento Rural

GI-TB Territorio - Biodiversidade