Deforestation and forest fragmentation in the highlands of Eastern Ghats,India

Tropical forest cover change along with increasing fragmentation has detrimental effects on the global biodiversity.In the current study change in both forest cover and fragmentation of Koraput district have been assessed in the past three decades(1987-2017)and future decade(2017-2027),which has been modelled using logistic regression showing a gradual decrease in the forest cover and increase in fragmentation.The long term deforestation rates from 1987 to 2017(current period)and from 1987 to 2027(predicted period)were found to be-0.018 and-0.012,respectively.Out of the total geographical area,2027 number of grids(1 km^(2))out of 8856 grids were found to have shown extinction of forest in the study period.The conversion of forested lands into other land uses has been one of the major causes of deforestation in Koraput,especially because of the increasing mining activities and establishment of three major industries namely National Aluminium Company(NALCO),Damanjodi,Hindustan Aeronautics Limited(HAL),Sunabeda and Ballarpur Industries Limited(BILT).The forest fragmentation reveals a negative trend,recording highest conversion from large core fragments to edge(191.33 km2)and the predicted period has also shown the same trend of negative change,which poses serious danger to the structure of the forests.Out of all the landscape matrices calculated,number of patches will increase to 214 in 2027 from 93 in 1987.In the test between geographically weighted regression(GWR)and ordinary least square regression(OLS),GWR was the better fit model for drawing a spatial relationship between forest cover and fragmentation changes.The study confirmed that the forest cover change has impacted the forest fragmentation in the study area.The programmes like REDD+should be implemented along with the experiences of Community Forest Management and the joint forest management should be intensified at community level in order to develop better management practices to conserve habitats in biodiversity rich areas.

Assessment of different grass species extracts as source of micronutrients in prawn Macrobrachium rosenbergii feeds

The present research is an attempt to screen five perennial indigenous grass species for their biochemical constituents seasonally for one year in order to determine the exact season for the harvest of the target species which will be used as feed ingredient.Among them,Cynodon dactylon has shown better result compared to other grass species and was hence incorporated as micronutrient in the formulated feed.Macrobrachium rosenbergii culture was carried out by feeding conventional and formulated feed(prepared from grass species)in tanks and ponds filled with spring water for 180 days in 2020 in the Eastern Ghats region of Koraput district,Odisha,India.Two treatments namely T_(1)and T_(2)having four replications each were supplied with commercial feed and formulated feed.Feeds were applied as per the body weight of prawns at 20%for the 1st month,15%for the 2nd month,10%for the 3rd and the 4th month,5%for the 5th month and 2%till the end of the experiment.The water temperature,pH,dissolved oxygen,transparency,nitrate,phosphate,silicate,Chl a in the culture tanks and ponds were monitored fortnightly.ANOVA results between all the water parameters for both culture tanks and ponds showed significant variation(P<0.05).The survival rate(77.0%±0.89%),daily growth rate(0.233±0.05)g/day,specific growth rate(4.657%±1.04%)per day and condition index(2.638±0.05)were found to be highest in prawns fed formulated feed.The feed conversion ratio varied from(2.03±0.05)to(2.68±0.04).Benefit cost ratio of field culture were 1.46 with yield of 702 kg/ha in conventional feed and 1.75 with yield of 950 kg/ha in formulated feed respectively.The study proved grass extracts to be efficient micronutrients for prawn feed which can be easily adopted in prawn production.