بررسي رابطه خصوصيات فيزيكي و شيميايي خاك هاي مارني با اجتماعات گياهي (مطالعه موردي : دشت بيرجند)

Investigation on relation between physicochemical characteristics of marl soils and plant communities (Case study: Birjand plain)

The Study on vegetation and soil charactristics of marl lands is important in management programs.The Study area was Birjand plain. First, geomorphplogical units were identified by use of topographic, land usability, lithology maps and aerial photoes. After field controlling, sampling was done in homogenic units by systematic-randomized method. Size and number of plots were determined by minimal area and statistical methods respectively. Vegetation and soil samples were taken in each plot. Soil parameters such as texture, pH, EC, SAR, lime and gypsum were measuered in the laboratory. Differences between plant communities and reaction to soil variations were determined by analysis of variance and CCA in SPSS and Canoco 4.0 softwares. Results showed that different plant communities had different reactions to soil charactristics. Suaeda fruticosa, Chenopodium album, Salsola rigida and Aellenia glauca had the highest correlation with SAR but Salsola rigida and Aellenia glauca had shown the high correlation with EC, silt and gypsum amount. Also, entrance of invador species (Cousinia eryngium) caused to low reaction of plant communities to edaphic factors. The other species had negative reaction to soil salinity and none of them had response to pH.