Study of soil parameters and biological factors in rhizospher of pinus and acacia at Taleghani and Cheetgar Parks in Tehran province

The knowledge of the effective factors to maintain, revive and exploit herbal covering regions in which the soil is facing water and nutritional shortage, or even the kinds of plants suffering from salinity and water shortage is of essential importance. In soils suffering from insufficient nutritional elements, the continuation of plant life depends on presence of microorganism such as mycorrhizal fungi. Mycorrhizal fungi are useful symbionts for plants, and helps plants to absorb water and nutrients such as phosphorus, nitrogen, potassium and other minerals. The use of mycorrhizal fungi could also help remove some fundamental problems of stabilizing jungles and green spaces. In this study two regional parks, (Taleghani park and Cheetgar park), which are different in regards of stability and growth of Tehran pinus species (Pinus eldarica) and in case of (Robina pseudo acacia) had been selected and were studied and compared from view of pedology. On the other hand in regard of biological factors, mycorrhizal colonization, root phosphorus and root proline of the selected trees were examined. The soil of whole regions was sandy loam, the pH was the same in whole regions, the amounts of Na, Cl and EC were more in soil of Taleghani park. Pinus trees of Taleghani park which have better growth comparing to pinus trees of Cheetgar park region, had significantly (P≤0.05) more root symbiosis than pinus trees in Cheetgar Park region. Acacia trees in both regions had rather similar growth and there was not a significant difference between the two regions. There was no significant difference in the average of spore numbers for pinus rhizospher between two regions, where the number of spores in rhizospher of acacia trees in Taleghani park comparing to the station 2 of Cheetgar park was significantly (P≤0.05) more. Proline content in root of pinus and acacia in Taleghani park was significantly more than that in Cheetgar park. Root phosphorus concentration for pinus and acacia was significantly higher in station 3 of Cheetgar park than other stations. There was no significant difference for phosphorus in root of acacia between different stations. Based on the results, low concentration of nutrient elements in the soil of Cheetgar park compared to Taleghani park could be considered as a limiting factor for growth of pinus trees in this region. Generally, mycorrhizal fungi are aboundant in soils with low plant nutrients. In contrast, we found lower mycorrhizal colonization in Cheetgar park and it could be considered as another growth limiting factor for pinus trees in this region.