Biodiversity associated with an irrigated rice agro-ecosystem in Sri Lanka

Abstract

Irrigated rice fields are temporary wetland agro-ecosystems, managed with a variable degree of intensity. A survey was carried out in Sri Lanka to document the overall biodiversity associated with this unique agro-ecosystem, using a combination of sampling techniques to document different groups of fauna and flora. The total number of biota recorded and identified from the rice field ecosystem during the entire study period consisted of 494 species of invertebrates belonging to 10 phyla and 103 species of vertebrates, while the flora included 89 species of macrophytes, 39 genera of microphytes and 3 species of macrofungi. Of the total species documented, 15 species of invertebrates and one weed species are new records to Sri Lanka. Arthropods were the dominant group of invertebrates (405 species), of which 55 species were rice pest insects, and 200 species were natural enemies of pest insects. The fauna and flora recorded from the rice field were observed to follow a uniform pattern of seasonal colonization and succession during successive rice cultivation cycles. The biodiversity of the irrigated rice agro-ecosystem interests both agroecologists and conservation biologists. Therefore, the integrated efforts of these two groups can result in the formulation of strategies based on biodiversity as an organizing principle in the sustainable management of the rice field agro-ecosystem.

Whole issue

“…The agronomic practices change the physical, chemical and biological conditions in the rice ecosystem, making them less favourable for certain organisms and temporarily more favourable for others (Heckman 1979;Bambaradeniya and Amerasinghe 2003). Rice agroecosystem have a great variety of aquatic organisms, well adapted to this temporary and highly manipulated ecosystem that is periodically disrupted by various agricultural practices (Bambaradeniya and Amerasinghe 2003).…”

“…Rice agroecosystem have a great variety of aquatic organisms, well adapted to this temporary and highly manipulated ecosystem that is periodically disrupted by various agricultural practices (Bambaradeniya and Amerasinghe 2003). Temporary drying was a major factor that reduced the abundance of the recorded species.…”

Process of Wetland Loss in the Lower Nakdong River, South Korea

“…The paddy field is a temporary wetland that harbors many of the species that breed in natural temporary ponds (Lawler, 2001). Additionally, the paddy field has the potential to help sustain the regional diversity of many invertebrates and vertebrates that depend on aquatic/semi-aquatic habitat (Bambaradeniya and Amarasinghe, 2004). However, to maintain the ecological function as a wetland, low impact farming practices are required.…”

Microturbellarians (Platyhelminthes and Acoelomorpha) in Brazil: invisible organisms?

“…Most marine turbellarians are limited to the littoral zone of the ocean (Hyman, 1951). Freshwater forms may occur in temporary or permanent wetlands, such as lakes, natural or artificial ponds, pools, ditches, streams and rivers (Kolasa, 1991;Noreña-Janssen, 1995;Young, 2001), as well as in agroecosystems (Bambaradeniya et al, 2004;Vara and Leal-Zanchet, 2013). Some marine flatworms, such as acoels and polyclads, and freshwater rhabdocoels are planctonic (Hyman, 1951;Rocha et al, 1990;Dumont et al, 2014).…”