Philippine ricefields: assessing its ecological impacts
by Rita T. dela Cruz
January-March 2000 Volume 2, No.1
Due to the urgency to expand our scientists’ understanding of the ecological values of ricefields in the Philippines, a workshop was conducted last 22 March 2000 at the main conference room of the PCARRD headquarters in Los Baños, Laguna. The one-day event gathered some of our scientists from different concerned areas. Sponsoring this event were the Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCARRD), Philippine Rice Research Institute (PhilRice), University of the Philippines Los Baños-School of Environmental Science and Management (SESAM-UPLB), and Asia Rice Foundation (ARF).
According to Huke’s study, as cited by the report of Dr. Ben S. Malayang, dean of SESAM, a universal feature of the Philippine landscape are ricefields that cover 12% of our total land, second to the highest among our neighboring ASEAN countries (second to Vietnam). Moreover, our rice areas can be classified into four, namely: upland, deepwater, irrigated, and rainfed. The irrigated is further classified into wet and dry, while the rainfed are either shallow or intermediate.
Many studies have explored the economic impacts of ricefields as well as the effect of rice-land use in the performance of national economies. When it comes to social and cultural systems, much is also known about its impact on rice production. What is barely understood according to Dr. Malayang, is how the presence and expansion of our rice areas affect their ecological dynamics. Though some studies have already provided insights regarding this aspect of rice production, still they have proved to be limited in scope and replication.
With this problem in mind, a pool of experts was convened to expand the understanding of the larger ecological implications of committing more areas of our landscape to rice production. Also stressed was the need to understand the systemic contributions of our ricefields to the biophysical and socio-cultural interactions of our national life.
The ecological value of ricefields in the Philippines was discussed in terms of the direction and degree of their impacts on biodiversity, landscape change, hydrologic and chemical cycles, and energy flow across the larger tropical environment of the country.
At the end of the workshop, participants were able to identify some of the ecological interactions occurring in the Philippine ricefields, determine how these interactions could be better understood, and enumerate key questions for future research on Philippine ricefields that affect the wider ecological dynamics in the Philippines.
The workshop was highlighted by four paper presentations on Biodiversity of Microflora in Wetland Rice Fields; Biodiversity of the Macro Flora in the Rice Field: Weeds; The Biodiversity of Macro Fauna: Vertebrates in Rice Fields; and Biodiversity of Macro Fauna: Invertebrates in Philippine Rice Fields. Presenters included Dr. Ireneo J. Manguiat of the Department of Soil Science, Dr. Juliana S. Manuel of the Department of Agronomy, Dr. Pablo P. Ocampo of the Institute of Biological Sciences, and Dr. Alberto T. Barrion of the Entomology and Plant Pathology Division, IRRI.
On a separate discussion about the impact of landscape change, two papers were presented: its effect on Soil Physical, Chemical and Morphological Properties of Rice Fields, and its effect on the Hydrology and Microclimate of Rice Fields.
With these papers presented during the workshop, participants were able to engage in laying the basis for forging a new agenda on rice R&D in the Philippines.