They attributed this shift to changes in regional climate. Similarly, subalpine forests have shifted upwards by 60—80 m in the Southern Urals during the last 70 years and by m in the Polar Urals during the last 35 years [ 13 ]. Furthermore, across 26 mountains in Switzerland, alpine flora has expanded toward the summits since the plots were first censused in the [ 9 ].
These Mountains are structurally part of the arid mountain chain which extend eastward and southward from Cyprus into Hatay and Syria, along the Turkish- Iranian border southeast through Kermanshah and Neyriz in Iran and finally across the Arabian Gulf into Oman [ 14 ]. The Hajar Mountains are divided broadly into Al-Hajar ash-Sharqi and Al-Hajar al-Gharbi the Eastern and Western Hajar, situated respectively to the east and west of the Jebel Akhdar range and comprise various smaller ranges and massifs which have independent local names, e.
There are two basic seasons: a prolonged hot, dry summer from May through October, and a mild to warm winter, with occasional rain, from November through April. Temperatures at mountain elevations are relatively lower, compared to above. The peak of the most recent glaciation in the eastern Arabia occurred at c. At that time, sea level was about m lower than at present and the Arabian Gulf was completely dry, with the shoreline outside the Strait of Hormuz [ 14 , 16 ].
This allowed free dispersal of plants and animals between the Arabia and southern Iran and the Makran region encompassing south-eastern Iran and the southern part of the province of Baluchistan in south-western Pakistan. Climatically, the initial retreat from the glacial maximum was accompanied in Eastern Arabia by a period of extreme aridity from c. This indicates that overlapped flora between Eastern Arabia and the southern Iran and the Makran region have separated before 11, years. As the temperature increased greatly in the Eastern Arabia during that time, many of the species might extinct.
Assessing the impacts of climate change on biodiversity: is below 2 °C enough?
Other more sensitive species, however, retreated to the highest elevations of Hajar Mountain e. The expected increase in the global temperatures on the high mountains of the eastern Arabia would negatively impact these temperature sensitive species of the Iranian origin. The northern mountains of Oman are classified as a local centre of plant endemism in the eastern Arabia [ 19 , 20 ]. Elsewhere, P.
Climate Change Is Becoming a Top Threat to Biodiversity
The majorities of the most common and less common species have the centers of their range in Iran or neighbouring areas of Central Asia. The common species include Artemisia sieberi , Astragalus fasciculifolius, Centaurea wendelboi, Convolvulus acanthocladus, Cymbopogon jwarancusa, Ephedra pachyclada, Jureniaberardioides, Prunusarabica and Teucrium stocksianum and the less common species include Aegilops kotschyi, Dianthus crinitus, Leontice leontopetalum and Salvia mirzayanii [ 18 , 21 , 22 ].
In regions where climatic change may lead to warmer and drier conditions, mountain vegetation could suffer more as a result of increased evapotranspiration. This is most likely to occur in mountain climates under the influence of continental and Mediterranean regimes [ 7 ]. This is clear for Juniperus excelsa , subsp, polycarpos in open woodland in the central range of the Western Hajar Mountains. This species is present from m to the summit at m [ 23 ]. Below m, the juniper trees are either dead or in very poor condition and regeneration is virtually absent [ 24 ].
The juniper woodlands of Oman are unique to the Arabian Peninsula, present elsewhere in the highlands of southern Iran, Baluchistan and Turkey. Juniper would be one of the most threaten species if temperature increased up. The negative impacts of global warming on biodiversity at all levels mean that ecologists must quickly develop conservation strategies. A major role of conservation planning is to design reserve networks that protect biodiversity in situ [ 25 ].
For example, maintaining or enhancing the habitat heterogeneity would provide endangered species with microhabitats that could protect them from the elevated temperature, especially in arid regions. For example, deep narrow gorges played a significant role in marinating Moringa peregrina under the harsh conditions of high temperatures and low rainfalls in its northwestern range edge at Hajar Mountains in the eastern Arabia El-Keblawy and Khedr, submitted for publication.
The gorges are shaded most of the day. Shading would reduce the amount of received solar radiation and hence reduce the rate of evapotranspiration. Similarly, the two trees Pistacia khinjuk and Cordia sp. Quercifolia of Hajar Mountains are both represented by fewer individuals and their presence could be attributed to their protection in cliffs or ledges [ 15 ].