Floristic and edaphic attributes of three land use systems in Wayanad, Kerala

Abstract

The present study was conducted in Thollayiram area of South Wayanad Forest Division of Wayanad district. The objective of the study is to compare the various floristic and edaphic attributes of three land use systems, viz an ecologically fragile land (EFL), a section 5 land (as per section 5 of Kerala Preservation of Trees Act (1986) and vested forest found in South Wayanad Forest Division. A total area of one hectare was surveyed in each of the three land use systems. The floristic study revealed that species richness of these land use systems were 40, 26 and 32 respectively. The major associations of trees in the ecologically fragile land were Melicope lunu-ankenda- Litsea oleoides- Litsea wightiana and Diospyros nilagirica. In section 5 land, the major associations are Litsea wightiana- Dillenia bracteata and Diospyros nilagirica whereas the vested forest is dominated with Palaquium ellipticum, Myristica beddomei, Dimocarpus longan and Mesua ferrea. Total basal area of vested forest is 44.56 m2 followed by ecologically fragile land (37.47 m2) and section 5 land (33.60 m2). By comparing the Shannon –wiener index of these land use system, vested forest recorded the highest value (2.96) followed by ecologically fragile land (2.93) and section 5 land (2.80) whereas Simpson indices are 0.93, 0.91 and 0.92 respectively. Regarding vegetation structure, a typical three storeys was noticed for ecologically fragile land and vested forest but section 5 land has only two storeys. Texture analysis revealed that soil texture of these land use systems are sandy loam. The pH values of the soil ranges from 3.84 to 4.79. The higher value of bulk density was recorded for section 5 land (1.46 g cm-3) followed by ecologically fragile land (1.34 g cm-3) and vested forest (0.88 g cm-3). There is no significant difference in the values of organic carbon and available potassium across three land use systems whereas available phosphorous was significantly higher in vested forest. The information regarding diversity of ecologically fragile land in Thollayiram will be helpful to the state forest department in designing better strategies for the long term conservation of this ecosystem.