Ecology, Environment and Conservation Paper

ASSESSMENT OF SPATIO- TEMPORAL CHANGES IN CURRENT JHUM CULTIVATION OF THYSANOLAENA MAXIMA IN MAWTHEI VILLAGE OF UMSNING TEHSIL IN MEGHALAYA

Raymond Wahlangí and S.S. Chaturvedií

Abstract

Shifting cultivation or slash and burn agriculture is one of the most practiced forms of agriculture in the North- east as well as other hilly areas of India. A majority of tribal populations depend on this form of agriculture for their sustenance and livelihood; the Khasi and Garo tribes of Meghalaya are extensive practitioners of this form of agriculture in the state. Indian broomgrass [Thysanolaena maxima (Roxb.) Kuntze] is an important semi- domesticated non timber forest product (NTFP) of Meghalaya that contributes to the state’s economy and is currently in high demand in the market. The cultivation of broomgrass in Meghalaya has become an effective instrument for rural development as its cultivation needs minimum input and labour while generating a very attractive economic return; thus the cultivation of broomgrass has become somewhat of a status quo in the state. Over the years there has been an alarming increase in the rate of deforestation and land degradation as vast areas of forest land are cleared and converted to broomgrass plantations. This study aims at utilizing geospatial techniques for understanding the dynamics of the conversion of forest lands into jhum land for the cultivation of broomgrass. The area of interest chosen for this study was Mawthei village in Umsning tehsil of Ri- bhoi district in Meghalaya. This village is extensively known for practicing shifting agriculture for the cultivation of broomgrass. The study aims at determining the current jhum as well as the expansion rate of cultivation of broomgrass annually in the village using clustering analysis as well as on screen visual interpretation techniques along with field visits to confirm the accuracy of clustering analysis. A time series analysis of satellite data was performed for a period of 7 years (2013- 2019) using Landsat- 8 OLI satellite data. The Landsat- 8 OLI has narrower spectral bands, improved calibration and signal to noise characteristics, higher 12-bit radiometric resolution, and more precise geometry, compared to the Landsat-7 ETM. For this analysis, 2013 was chosen as the base year as Landsat- 8 was launched in this year only. The study reveals an alarming and unprecedented rate in the expansion and conversion of forest lands into jhum lands for broomgrass cultivation. With the current existing trend and “business as usual” scenario of expansion of current jhum for broomgrass cultivation, this can bring about a negative impact on the microclimate of the village as well as land degradation due to loss of soil from the exposed fallow lands. Thus, intervention as well as mitigation policies need to be formulated to safeguard the interests of the rural population while establishing sustainable practices for the benefit of the village and the state as a whole.