People rely on natural resources to provide for their basic needs, including food, shelter, and clothes, but also compete for the space occupied by natural habitats. Population growth and human development therefore affect biodiversity both directly and indirectly. The effects of humans on the environment, including use of land and other natural resources, are the greatest factors underlying the current declines in biodiversity. In Armenia, with its rich and unique biological resources, the impacts of human on the environment has become increasingly marked.

Historically, low human population densities and regulated use of natural resources protected the balance of ecosystems in Armenia. However, over the last 1,000 years human impacts on the land have increased, mainly through deforestation and increased use of pastures. Such problems have intensified over recent years with unprecedented population growth and urbanisation since 1920 (Table 2.8), resulting in increased human impacts not only on individual species, but also on whole ecosystems.

Table 2.8 Increases in population and human impacts between 1920 and 1990

The population density (Table 2.9) directly influences the impacts of humans on biodiversity. To ensure that human development is sustainable, society develops mechanisms to regulate impacts on biodiversity and natural resources, including laws, protected areas for threatened species and ecosystems, and regulations for use.laws, protected areas for threatened species and ecosystems, and regulations for use.

Table 2.9 Some parameters of current population

and human pressures in Armenia

Habitat modification and loss

Anthropogenic impacts have affected a large proportion of Armenia, and have led to damage and destruction to natural habitats. Over the last 50 years agricultural intensification has resulted in the loss of natural grasslands and wetland ecosystems, while felling of forest areas has resulted in substantial losses in biodiversity. Habitat loss has affected food resources and nesting opportunities for a range of species, and restricted range species have been particularly affected, including a number of threatened species. For example, the partial drainage of Lake Sevan affected the spawning areas for Sevan trout, leading to severe declines in this species.

Over-use of biological resources

In Armenia, both habitats and species have suffered from unregulated use. Although few figures are available, concern is expressed about the impacts of over-collection of wild plants and poaching of animals. Among species most at risk are plants of edible, medicinal or decorative use, and over-collection of such species has affected the semi-deserts, steppes and meadows in which they occur. Among animals, snakes have suffered over-collection for their venom, while the fish resources of Lake Sevan and other water bodies are declining as a result of over-fishing. Habitats, particularly pasturelands, have also suffered degradation through over-use. Over 50% of pasture lands are now degraded, and these show reduction in species diversity, succession with poisonous and inedible species, soil compaction, loss of vegetation cover and erosion.

Pollution

Pollution is a major issue in Armenia, involving not just current emissions, but the legacy from pollution during the Soviet era. Sources of pollution include industrial centres, mining enterprises, chemical and power plants, and vehicle emissions. Much pollution remains as a legacy from Soviet industry. While air pollution has declined substantially, heavy metal and chemical pollution of soil and water remains an important threat to biodiversity.

Invasive species

A range of species have been introduced to Armenia. Some species have expanded their ranges to the detriment of native species, and have resulted in population declines and disruptions of ecological relationships, affecting both biodiversity and agricultural systems. At present, most concern is expressed about the introduction of agricultural pests (including insects such as the Colorado bug and the Asian grasshopper). Among the most aggressive invasive plant species are Xanthium, Cirsium, and Galinsoga parviflora, while wormwood ambrosia (Ambrosia artemisiefolia) has expanded its distribution by over 200km2 within the last decade. The increasing levels of trade regionally and internationally, may result in increased introductions to Armenia, as a result on inadequate customs checks and quarantine regulations. The major dangers among invasive species include aggressive weed plants, insect pests, pathogens, fungi and raptors.

Climate change

An indirect impact of pollution on the natural environment comes from the predictions of global warming. Increases of 2-3°C are predicted for Armenia's climate, along with declines in rainfall, resulting in increased risks of desertification. This is likely to severely affect wetland habitats and associated species, while changes in the distribution of habitats may affect the range and viability of a number of species.