Effect of Fire on Composition, Biodiversity, and Functional Groups Changes in Semi-Steppe Rangelands of Southern Zagros

Document Type: Research and Full Length Article

Authors

1 Ph.D in Rangeland Science, Department of Range Management, Sari University of Agriculture Sciences & Natural Resources, Sari, I.R. Iran

2 Assistant Prof., Department of Forestry and Institute of Natural Resources and Environmental, Yasouj University, Yasouj, I.R. of Iran.

3 Assistant Professor, Rangeland Research Division, Research Institute of Forests and Rangelands, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran

Abstract

Fire as an ecological factor has both positive and negative effects on components of the ecosystem. The aim of the present study was to investigate the effects of fire on composition, diversity, and functional groups changes in the Tangesorkh rangeland of Boyer-Ahmad County. The fire took place in the summer of 2015. Two years after the fire, the characteristics of vegetation were measured in the 1 m2 plots. The results showed that 17 species were exclusively found in the fire region, 14 species exclusively in the control region, and 37 species were shared between the two regions. The results of mean comparisons showed that among the study species, 21 species had a significant response to the fire in terms of canopy cover percentage. Fire in the area increased the Simpson and Shannon diversity index and Margalef richness index. The fire caused the canopy cover percentage of annuals, perennials, grasses, forbs, Throphytes, Cryptophytes, Hemicryptophytes, Chamaephytes, Asteraceae, Caryophyllaceae, Fabaceae and Rubiaceae and Poaceae increased significantly compared to control. The redundancy analysis (RDA) results showed that the species had different responses to fire, so that the canopy cover of Bromus danthoniae, Vicia villosa, Bromus tomentellus, Astragalus hispanicus, Ziziphora tenuior, Bunium rectangulum, Ferulago angulate and Gundelia tournefortii were increased in the regions where fire occurred. According to the results of this research, functional groups have important roles in determining the responses of plant species to the environmental disturbances; hence, they can affect the secondary succession after the wildfire in rangelands.

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