Conversion of fundamental niche to realized niche: an analysis of indigenous tulaipanji rice in raiganj cd block, Uttar Dinajpur District, West Bengal, India

Tulaipanji is one of the oldest indigenous aromatic rice varieties in the physiographic division of the North Bengal plain of West Bengal, India. Raiganj CD Block of Uttar Dinajpur District, located in this physiographic division is very famous for the cultivation of this rice variety. Cultivation of this rice has been done in this natural habitat for more than 100 years back. Thus, this rice variety adapted itself in its microhabitat or niche. The fundamental niche of this rice was spread in major parts of the Raiganj CD Block. But the introduction of the cultivation of HYVs of rice mainly Swarna started to decrease the fundamental niche of Tulaipanji. Cultivation of Swarna requires very high chemical inputs which change the soil properties in such a way that badly affects the growth and aromatic quality of the Tulaipanji rice. As a result of which, the vast fundamental niche of this rice, converted into small restricted realized niche out of which cultivation of this rice become totally ignored. This study incorporates the using GIS and GPS techniques besides the intensive field study to delineate the niche zones. The main aim of this paper is to highlight the causes behind the conversion of the fundamental niche of the Tulaipanji rice to the realized niche in the study area as well as its further impacts.