Abstract. Carbonate biological hard tissues are valuable archives of environmental information. However, this information can be blurred or even completely lost as undergo diagenetic alteration. This is more likely to occur in aragonitic skeletons because bioaragonite often transforms into calcite during diagenesis. For reliably using geochemical proxies, it necessary understand depth the alter...

the present study was conducted in the rangeland of glandrood watershed in the province of mazandaran. the objective of this study was to compare between the ecological amplitude of festuca ovina l., and poa bulbosa l., using the function hof along the gradient of the environmental variables. for this purpose 150 plots of 1m2 were established along the altitude gradient. the sampling method was...

cancers belong to a group of disorders which are very important for researchers.  because they have several types and cause mortality in human beings. many  investigations are performing in order to introduce cheaper drugs with lower side  effects especially with natural sources. ferula genus grows all over the world but  some of them are endemic to iran. many investigations have proved differe...

BACKGROUND In Iranian folk medicine, several plants are used for treatment of gastrointestinal disorders, such as diarrhea and spasm. One of these herbal medications are the essential oil yielded from seeds of Ferula assa-foetida L. and an oleo-gum-resin known as asafetida, which is exudated from its root. F. assa-foetida grows wildly in south and central mountains of Iran. AIM In this study,...

This study was done to investigate the nutritive value of Festocaovina, Agrostisgiganta and Avena sativa using sheep rumen and feces liquor as sources of micro-organism through gas production method. Rumen and feces liquor were collected from three fistulated sheep. Rangeland species sampling was randomly conducted from different areas of Guilan province. All the collected samples were initiall...

Understanding interactions between grasses and their herbivores is central to the conservation of species-rich grasslands and the protection of our most important crops against pests. Grasses employ a range of defenses against their natural enemies; silicon-based defenses have been shown to be one of the most effective. Silicon (Si) is laid down on the leaf surface as spines and other sharp bod...

Genetic diversity may play an important role in allowing individual species to resist climate change, by permitting evolutionary responses. Our understanding of the potential for such responses to climate change remains limited, and very few experimental tests have been carried out within intact ecosystems. Here, we use amplified fragment length polymorphism (AFLP) data to assess genetic diverg...