By Faranak Bakhtiari

Iranian mountains: a great place to see plants you never have seen before

November 24, 2020 - 18:25

TEHRAN – Iran is a mountainous country harboring an extraordinary vascular flora including many rare and endemic plant species in the alpine zone. The importance of mountain biodiversity for the whole of humanity triggers the necessary changes both in attitude and behavior required to secure mountain biodiversity and its genetic resources for future generations.

Mountain environments cover about 12 percent of the world’s land surface and directly support those 22 percent of the world’s people who live within mountain regions and their immediate forelands. Mountain biodiversity provides basic ecosystem services such as freshwater, timber, medicinal plants, and recreation for the surrounding lowlands and their increasingly urbanized areas, according to the ‘mountain biodiversity and global change’ report published by FAO in 2010.

By preventing erosion, mountain plant diversity secures livelihoods, traffic routes, and catchment quality. More than 50 percent of mankind benefits from mountains as the world’s water towers. They host some of the world’s most complex agro-cultural gene pools and traditional management practices.

Based on total mountain land area only, a conservative estimate of the world’s mountain plant species is 50,000 species of flowering plants (out of a total of ca. 260 000). Given the inclusion of tropical lowland mountains in the above definition, the number may well be twice as high.

On average, a single mountain system such as the Alps, the Pyrenees, the Scandes, or the New Zealand Alps hosts a few hundred (often 500–600) different species in the alpine belt alone. There are no such estimates available for animals, invertebrates (e.g., insects) in particular, but a common estimate for temperate to cool climates is a 10-fold higher animal than plant species diversity.

Iranian mountains among unique global heritage

Referring to the rich biodiversity and unique characteristic of mountains in the world, the report calls Iran a great place to see plants you have never seen before; according to which, more than 100 mountain peaks can be found in Iran, some in the Zagros and Alborz mountains which reach altitudes of more than 4000 m.

The upper limit of vascular plants is 4800 m, the highest point where a plant has been found in Iran. A first evaluation of the vascular flora shows that 682 species belonging to 193 genera and 39 families are known from the alpine zone. This zone is characterized by many species of hemicryptophytes and thorny cushions; species numbers decline strongly as altitude increases. The mountain flora of Iran is exceptional.

The Iranian mountains are situated between Anatolia/Caucasus and the Hindu Kush; their flora contains elements from both regions. However, more than 50 percent of these species are endemic to Iran (they occur nowhere else), and some are remarkable relic species, primarily local endemics with a narrow ecological range. These plants need strong conservation and protection management, not only because they are rare but because the ecosystems where they live are fragile, often very restricted, small and isolated in high elevation areas.

These plants adapted to the cold are particularly vulnerable to the impacts of climate change, and intensive grazing over large parts of Iran’s mountains is expected to exert additional pressure on them. Many of these plants are potentially endangered and vulnerable species, and their threatened status should be assessed according to the International Union for the Conservation of Nature (IUCN) criteria.

Land-use change among most dangerous incidents

The report then points to the most dangerous incidents that severely affect the mountain biodiversity, including natural disasters, wildfire, overgrazing, and the most destructive land-use changes caused by humans.

The natural disasters in the form of landslides, floods, and avalanches strike mountains each year, affecting only small areas but also habitat diversity and ecosystem dynamics. These natural disturbances result in surprisingly fast natural regeneration of plants. In contrast, human impact dominates large areas, and its effect is often irreversible. Land-use change's effects can be more dramatic than natural disasters or climatic change.

Climate change impact on diversity

Then it highlights that climate change can have dire consequences for mountain diversity, including an increase in atmospheric concentrations of greenhouse gases, progressively earlier onset of spring activities, migration of plant and animal species, or even extinction.

 Global warming threatens mountain biodiversity by forcing life zones upslope, thus reducing the higher land area for organisms specifically adapted to the cold. With higher temperatures predicted, longer summers with a greater incidence of drought are expected in many mountain regions worldwide. Although effects vary regionally and the extent of the increase of temperatures is debated, it is clear that the Earth has experienced exceptional warming during the past century, one that cannot be explained by natural drivers.

Climate change is linked to an increase in atmospheric concentrations of greenhouse gases (Carbon dioxide CO2, Methane CH4, Nitrous oxide N2O, halocarbons) caused by human activities.

Greenhouse gases affect the absorption, scattering, and emission of radiation in the atmosphere and at the Earth’s surface (IPCC 2007). Studies show that temperatures are very likely to increase more in the 21st century.

Rising temperatures are coupled to a decrease in the mountain glacier area, shorter duration of snow covers at elevations below treeline in temperate and boreal latitudes, and increased annual precipitation with otherwise changing seasonality, i.e., not excluding periodic droughts in summer.

It is expected that many small glaciers will disappear, while the volume of large glaciers will be reduced by 30 to 70 percent by 2050, with consequent reductions in discharge in spring and summer.

Also, climate warming since the 1960s has led to a progressively earlier onset of spring activities below the tree line. Above the tree line, warming-associated increases of precipitation may enhance snowpack in some regions and thus even delay spring.

Plants show an earlier bud break or flowering, while increased temperatures have changed the timing of hibernation, breeding of animals, and, in some cases, the dependence of predators on traditional prey. The effects of climate change on one species are likely to affect a cascade of other species in the food web.

Another widely observed phenomenon related to climate warming is the migration of plant and animal species. In the northern hemisphere, a northwards shift of bird and butterfly species has been observed, as well as migration to higher elevations. The size of the cool habitats, however, will shrink significantly, leaving less space for more species.

Protecting valuable mountainous ecosystems

 Management of mountain biodiversity has increasingly been recognized as a global responsibility. In the past 40 years, protected areas have increased six- to eight-fold, largely in mountain areas, expanding from 9 percent of the total mountain area in 1997 to 16 percent in 2010.

While protected areas are essential, they alone cannot ensure the conservation of biodiversity or cultural heritage. Traditional indigenous communities often use and manage biodiversity in mountain protected areas and maybe even more threatened than biodiversity itself.

Mountain regions where people live and work require innovative and respectful approaches to conservation; local people should be encouraged towards stewardship of both their natural and cultural heritage. Participation of mountain communities at all stages is crucial in the sustainable management and use of biodiversity.

A gradual paradigm shift in conservation policies and practices has included the acceptance of communities as an integral part of national conservation initiatives and the integration of many global conventions.

Mountain land users also may be compensated for the lack of on-site benefits through payment for environmental services.

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