Relationships between environmental variables and vegetation across mountain wetland sites, N. Iran

Abstract

Abstract:The mountain wetlands studied represent a unique habitat on the southern slopes of the Alborz mountain range, the second largest range in Iran. In comparison with other parts of this range the western section is ecologically and botanically unknown. Floristic and vegetation variation were assessed using diverse environmental variables along a broad altitudinal span (350 m to 3200 m a.s.l.). Using both statistical and ordination analyses floristic variation was assessed on three defined altitudinal belts which were delimited based on Alborz macro-climatic boundaries. The distribution of individual wetland plant species, of phytogeographic elements and of life-forms all differ among altitudinal belts. This result is also shown in both direct and indirect analyses of ordinations. The proportion of geophytes significantly increases with altitude and geophytes are very well represented in the upper altitudinal belt. The number of species of a narrow phytogeographical distribution (e.g. endemics) increases with altitude, soil pH and EC declined with altitude. The first axis of DCA ordination with passively projected environmental variables indicates that, organic matter and concentration of Fe 2+ are increased toward higher altitude. The second axis of ordination is related to both soil texture and slope inclination. The distribution of species in the CCA species plot is also close to the distribution of those in the DCA ordination. This study indicates that altitude and slope together with other dependent environmental variables (pH, EC, Ca 2+ and soil texture) are the main ecological factors controlling species distribution across the Western Alborz wetland sites.

Improving the prediction of plant species distribution and community composition by adding edaphic to topo‐climatic variables

“…; Kamrani et al. ). These predictors may have lacked influence in the models because our study area, although reasonably large (700 km 2 ) and encompassing a wide environmental gradient (400 to 3200 m elevation), does not span the entire soil texture gradient, and therefore lacks plots displaying extreme values of silt, sand or clay content (App.…”

“…The texture data (sand, silt and clay content) were not good predictors of our species' distributions, contrary to what would be expected based on several previous studies (Barrett 2006;Peper et al 2010;Kamrani et al 2011). These predictors may have lacked influence in the models because our study area, although reasonably large (700 km 2 ) and encompassing a wide environmental gradient (400 to 3200 m elevation), does not span the entire soil texture gradient, and therefore lacks plots displaying extreme values of silt, sand or clay content (App.…”

Elevational gradient and vegetation‐environmental relationships in the central Hyrcanian forests of northern Iran

“…Euro‐Siberian (ES), Irano‐Turanian (IT) and Mediterranean (M)) were based on the combined viewpoints of Zohary () and Léonard (). These elements were classified into four categories to provide summary data for further statistical analysis (Naqinezhad et al , Kamrani et al ). A PE is a group of plant taxa that share similar centers and limits to their total geographical distribution: PE 1 ‘broadly pluriregional’ (wide‐ranging taxa associated with more than three phytogeographic regions); PE 2 ‘narrowly pluriregional’ (plants found in two or three phytogeographic regions, i.e.…”

Distribution patterns of plant communities and their associations with environmental soil factors on the eastern shore of Lake Taihu, China

“…The demand for geological environment including space and mineral resources is increasing with the growth of the economy; economic growth is likely to destroy the balance of the geological environment. Numerous investigations have been carried out to understand water quality, aquatic vegetation, ecosystem health assessment, and blue-green algae outbreaks in Lake Taihu (Kamrani et al 2011;Li et al 2012;Li et al 2015). Unfortunately, studies have rarely considered the relationships between the spatial distribution of vegetation and soil factors, particularly in the eastern section of the Taihu lakeshore.…”