Vulnerabilities - Terrestrial biodiversity
There are approximately 1700 vascular plant species in the Latvian flora of which almost one third are non-indigenous species that have spread because of human activities (1).
Over the time period 1965 – 2000 the vegetation period in Latvia has increased on average by 8 days. Typically, the ratio of coniferous stands has decreased and the ratio of deciduous stands has increased over this period. Changes in the ratio of various tree species is related mainly to land-use change (natural and artificial afforestation of non-agricultural lands) and climate impact (increase of temperature and precipitation), as well as soil eutrofication. Transformation of plant and animal species and their systems occurs under the impact of three main, interconnected factors: environmental factors – human economic activities, climate fluctuations (currently, the climate warming) and environmental enrichment (eutrophication) (2).
Currently, the indicators for intensive biota transformation in Latvia are the change in the number of species and in the share of the prevailing tree species in forest stands ocurring as a result of the above mentioned environmental factors. Over the time period 1995 – 2005, the area occupied by coniferous trees has decreased by 5% (spruce by 10%, pine-trees by 3%); the area occupied by deciduous trees has increased by 12% (aspen by 52%, grey alder by 27%, black alder by 13%, birch by 6%). In recent years, the area covered by stands of broad–leaved trees has decreased: oaks by 2%, – and the more widespread broad-leaved tree species, the ash-tree – by 12% (2).
During the past decades, the biota of Latvia, and environment in general, has become more dynamic, the invasion of new species of flora and fauna occurs considerably faster, biocenosis and biotopes are changing. This process is reflected by the increase of the number of foreign species that has occured during the past decades of the 20th century. Especially adverse impacts to the economic development of the country already in the near future, may be caused by the rapid increase of the ratio of unstable forest pioneer stands (birch, aspen and grey alder) and the degradation of stable or so called climax forest stands (stands of spruce, oak and ash-tree) (2).
The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Latvia.
- Ministry of Environmental Protection and Regional Development (2001)
- Ministry of the Environment of the Republic of Latvia (2006)