What is biodiversity?

As defined in the Convention on Biological Diversity, biodiversity is the variety among all living organisms and their habitats that is manifested on several levels:

• genetic diversity is the variety among the individuals of the same species, ex. among the wolves in the pack. Therefore the wolves may differ in colour of their fur. The colour in an individual is saved in the shape of nucleotide sequence of a DNA chain. Part of the chain that codes one characteristic is called a gene.

• Species diversity is the variety among species such as animals and plants in a lake. Identifying biodiversity on this level is the easiest and most common because it can be expressed with the number of species present. Until the year 2001 in Slovenia there were about 22,000 recorded animal and plant species, which is a lot less than the estimated number of all species in Slovenia – 50,000 – 120,000 species. The numbers change constantly because of the discoveries of new species.

• Ecosystem diversity is not only the variety of organisms itself but also includes the diversity of their interactions. Organisms are connected among themselves and together with the physical environment form an ecosystem. Because of the inclusion of the connections among them, we can by influencing on one species influence on the whole ecosystem, since every species has a specific role in the ecosystem. Higher number of species means higher number of interactions that makes the ecosystem more stable and resistant to changes.

Because our territory is located at the intersection of Alpine, Pannonian, Dinaric and Mediterranean biogeographical region, Slovenia is one of the hotspots of biodiversity in Europe. The diversity of substratum has influence on the diversity of the relief and consequently on the diversity of the soil and climate conditions. These diverse factors are expressed in great diversity of ecosystems and plant and animal species. In Slovenia there are more than 3200 species of vascular plants (ferns and flowering plants), while the fauna is represented with 13,000 -15,000 species, from which 4000 are endemic. Slovenian territory that accounts for only 0.004 % of Earth's surface, represents a home for 2 % of all known terrestrial animal species.

Inland waters all over the world represent less than 1 percent of Earth's surface or approximately 2 percent of land, but are inhabited by 2.4 percent of all known species, among them more than 10 percent of all animal species and more than 35 percent of all vertebrates.

Numerous organisms from bacteria to the otter represent the inland water biodiversity in Slovenia. We do not know the exact number. The number of known species changes with discovering new species. In particular the invertebrate groups are well represented. For example, there have been more than 200 species of caddisflies (Trichoptera), 112 species of molluscs (Mollusca), about 100 species of stoneflies (Plecoptera) and approximately 190 species of beetles (Coleoptera) recorded in Slovene freshwaters. These organisms spend at least part of their lives under water. Among the vertebrates there are two groups that are most water-bound: fishes in a broad sense (Pisces, 93 species) and amphibians (Amphibia, 20 species), while some reptiles, birds and mammals predominately use water as foraging habitat. There is also a number of plant species that grow in and around the water, from unicellular algae to trees. For example we can take the variety of algae, which is different in different inland waters. Till the year 2009 there was more than 2200 species of algae recorded in Slovenia. Only in oxbows of Mali Bakovci (oxbows of the river Mura) they have recorded 107 different algae in 2005-2006 and among them there were 12 new taxa for Slovenia! The most frequent were diatoms, which are not visible to the naked eye. So if you do not see something, it does not mean that it is not there.

Inland waters are not only great in diversity of species, but also in ecosystems. We know flowing (lotic) and static (lentic) water, swamps, marshes, groundwater ... Different surfaces create different water bodies with different characteristics. In larger static waters the development of typical lake flora and fauna, such as plankton, is possible. A special place among inland aquatic ecosystems hold intermittent lakes, which require from the present organisms the ability to adapt to the rhythm of drying out and filling up of the lake. Watercourses with their dynamics create and maintain numerous habitat types that may disappear if this dynamics is modified or abandoned (gravel, oxbow, wetland forests ...). They link the populations and contribute to spreading of the species. There are different types of habitats where the water only occasionally covers the ground: marsh, wetland forest, river floodplains, wet meadows and marshes. Humans with their activities create artificial water bodies that may be important secondary habitats (reservoir lakes, ponds, canals ...). Different organisms inhabit different environments.

Sources:

Slovenian Environment Agency 2001. Review the status of biodiversity and landscape diversity in Slovenia. Ljubljana, Ministry of Environment and Spatial Planning of Slovenia, Slovenian Environmental Agency: 224 p. In Slovene.

http://www.biotskaraznovrstnost.si/index.htm, 17/02/2012. In Slovene.

BioFresh project – Background. 14/02/2012. In English. 

Janežič L. Biodiversity. V: ECOQUIZ 2010/2011 – Material for ecoknowledge contest for high school. DOVES - Slovenian Foundation of Environmental Education in Europe - Programme  Ecoschool as way of life: 8-25. Available on teh Internet, 13/11/2011.

Convention on Biological Diversity. 17/02/2012.

Krivograd Klemenčič A., Toman M.J., Balabanič D. 2009. Records of new algal taxa within various aquatic and aerophytic habitats in Slovenia. Natura Sloveniae 11 (2): 5-26. Available on the Internet, 03/02/2012. In English.

Krivograd Klemenčič A. in Balabanič D. 2010. Phytobenthos and water quality in the oxbows of the river Mura. Natura Sloveniae 12 (2): 5-22. Available on the Internet, 03/02/2012. In Slovene.

Mršić N. 1997: Biodiversity in Slovenia. Slovenia - "hot spots" of Europe. Ministry of the Environment and Spatial Planning, Department for the Protection of Nature, Ljubljana. In Slovene.

Sket B., Gogala M., Kuštor V. (eds) 2003. Fauna of Slovenia. First print. Ljubljana, Tehniška založba Slovenije: 664 p. In Slovene.

The Institute of the Republic of Slovenia for Nature Conservation 2010. People with nature, nature for people. Biodiversity is our life. Ljubljana: 40 p. Available on the Internet, 01/02/2012. In Slovene.

Fisheries Research Institute of Slovenia: Slovenian and Latine (Kottelat, 2007) names of fish and lampreys in inland waters in Slovenia. Available on the Internet, 14/03/2012. In Slovene.