Floristic study on some selected paddy fields of Thiruvananthapuram district, Kerala

Agricultural landscapes have attracted increasing attention in connection with the general rise of concern about the conservation of biodiversity. The predominant agricultural land use throughout Asia is paddy farming for the monoculture cultivation of rice. Few studies have examined plant biodiversity in paddy fields. Even though subjected to repeated human disturbance, many plant species persist within the paddy landscape. The present study was undertaken to understand this unique ecosystem by assessing the floristic richness of paddy fields after harvesting the rice to before harvesting rice. The study area located in Thiruvananthapuram District of Kerala. A total of ten fields were randomly selected for the study and five quadrants (1 m x 1 m) were also selected randomly from each field. A total of 44 species were observed belonging to 41 genera of 22 families with Poaceae being the dominant family. Flora on the field proper, bunds and ditch was different. The natives and dicots species out numbered the exotics and monocots respectively, and a gradual increase in the richness was observed from April to July. All species recorded in the field were economocally important. The present study reveals a great diversity of herbaceous plants in the study area. Recent studies shows that wetlands are under more extreme pressure. Threats to wetlands may be natural, manmade or both. Moreover, agricultural practices influenced the species composition. The relation between vegetation and agricultural practices makes an important contribution to the understanding of biological diversity in paddy ecosystems. Further studies are recommended to understood this unique ecosystem and to develop measures for conservation.