Application of random sampling in Floristic, Chorologic, and Life form studies Case study: Hashtad- Pahlou forest catchment

Background and objectives: Zagross forests as the most extensive part of forests of Iran, retain important plant diversity. Vegetation knowledge is the base for ecological studies, management, and plant species conservation. Many diverse methods in vegetation studies have been proposed, based on the aims of study, kinds of vegetation, phonologic and taxonomic constraints, and financial and administrative possibility, which surveying is the most common. This study aimed to investigate the ability of modified multiscale Whittaker plots with random distribution in different vegetation types, in determining floristic composition.
Materials and methods: In this study, floristic composition of Hashtad Pahloo forest catchment (8072 ha), contrary to common floristic studies, have been studied by sampling method using 21, 250 m² Wittaker multiscale plots. Sampling plots were distributed randomly in four distinct vegetation types including pure oak type (Quercus brantii Lindl.), Mixed oak and Acer (Quercus brantii Lindl., Acer monspessulanum L.), Shrubs and cushion plants (Daphne mucronata Royle, Cotoneaster morulus Pojark), and Mountain grasslands (Ferulago angulata Boiss., Tanacetum polycephalum Sch. Bip) types. Collected plants species were identified using authentic references and their life forms were determined based on Raunkier classification. Also Chorological study were performed based on Zohari eco regional division. IUCN classification and red data book of Iran were used to define Conservative situation of plant species.
Results: Results show that there are 211 species belong to 166 genus and 46 families in this landscape. Compositeae with 28 species (13.27%) were the biggest family. Irano-Toranian with 80 species (37.91%) and Mediterranean with 55 species (26.6%) were the most common chorologic types in this area. The most important life forms were Therophytes 88 species (43.9%), Geophytes 43 species (21.43%), Chamaephytes 25 species (13.2%), Hemicryptophytes 18 species (9.57%) and Phanerophytes 15 species (8.1%).
Conclusion: Comparison of the results of this study with earlier floristic study recently performed in this landscape revealed that random distribution of sampling plots in different vegetation types is able to identify common plant species while it needs less time and cost.