Dibang Valley Research Articles

Begonia neisti sp. nov. (Sect. Platycentrum, Begoniaceae), a new species from Arunachal Pradesh, India

Begonia neisti sp. nov., a new species of B. sect. Platycentrum, from Dibang valley of Arunachal Pradesh, India is described and illustrated. A detailed taxonomic description, along with a photographic plate, illustration, distribution map and conservation status are provided. The conservation status of the new species is preliminarily assessed as data deficient (DD) according to the IUCN red list criteria. Molecular data (ITS2) underwent phylogenetic analysis (maximum parsimony (MP) and Bayesian inference (BI)) to elucidate the relationships of the studied species within the genus.

Monitoring Land Use Land Cover Change and Its Impact on Climatic Parameters Using Remote Sensing and GIS: A Case Study of Lower Dibang Valley, Arunachal Pradesh, India

The changes in the socio-dynamics and the pattern of occurrences of natural hazards both at larger and regional scales have been influenced by the alterations in the Land use land cover change (LULCC) modifications. The LULCC of Lower Dibang valley of Arunachal Pradesh is investigated using contemporary tools of Remote sensing and Geographic Information system. A temporal analysis is done for the years viz, 2009, 2014, and 2021 using USGS Landsat satellite images. To determine the change in LULCC support vector machine a supervised classification method is used and is cross checked with Google Earth points for achieving accuracy and the temporal analysis is done by comparing each images pixel by pixel. The findings show that between 2009 and 2021, the region had significant changes in land cover in the following areas: forest area (–8%), rangeland/scrubland (–6%), barren land/bare soil/open rocks (–1%), agricultural (-2%), and water body/river (–1%). It was observed that lowland and higher altitude regions saw the majority of the LULCC alterations. In the seven tehsils of the Lower Dibang Valley of Arunachal Pradesh, which are located at varying elevations and slopes, the effects of LULC changes on climatic and environmental variables such as latent/sensible heat flow, temperature, precipitation, and specific humidity have been evaluated independently. This research paper’s methodology and results section includes a full explanation of the procedures followed and the outcomes.

Nutritional profiling and GIS-based grid mapping of Job's tears (Coix lacryma-jobi L.) germplasm

Thirty-two accessions of Coix lacryma-jobi belonging to different parts of North-Eastern India were taken from National Gene Bank at ICAR-NBPGR. Accessions were evaluated for nutritional traits and grid mapped to identify trait-specific germplasm and their geographic relationship. Proximate composition, total soluble sugars, total starch, total phytate in g/100 g, total phenol and antioxidant activity in % GAE, and minerals viz. iron, copper, zinc, and calcium in mg/100 g were estimated. Biochemical parameters like protein (15.9%), crude fat (4.66%), iron (13.6 mg/100 g), zinc (3.61 mg/100 g), and calcium (146 mg/100 g) have been recorded, which was higher than some members of its crop group. Principal component analysis revealed that the biochemical parameters such as starch, phenol, sugar, moisture, and antioxidants contributed significantly to generating diversity. Grid mapping for trait-specific germplasm revealed that high protein accessions could be collected from Meghalaya's East Khasi Hills and Arunachal Pradesh's Dibang valley; high iron and zinc content accessions from Meghalaya's East Khasi Hills; and low phytate content accessions from Nagaland-Manipur and Manipur-Myanmar border areas. IC0089381 and IC0416884 were identified as nutritionally superior accessions that can be used in breeding programs.

Ichthyological inventory of Lower Dibang Valley, Arunachal Pradesh, India

A total of 73 fish species were identified belonging to 8 orders, 20 families and 47 genera from different natural aquatic resources of Lower Dibang valley of Arunachal Pradesh. Conservation status of the fishes were worked out following the IUCN Red List Status and observed the presence of 2 Endangered species, 5 Near Threaten species along with 4 Vulnerable and 4 Data Deficient species. Report of getting three exotic viz., Salmo trutta, Oreochromis niloticus and Cyprinus carpio from the natural water bodies of the district is an ecological concern. Key words Dibang river, fish, conservation status, endangered, exotic

Siang river in Arunachal Pradesh splits red panda into two phylogenetic species

With the recent classification of red panda into two phylogenetic species, we propose ‘Siang river’ as a potential boundary for species divergence between the Himalayan red panda (Ailurus fulgens) and the Chinese red panda (Ailurus styani). Bayesian-based phylogeny and MJ network splited all the sequences of red pandas into two distinct clusters in accordance with the origin of the samples collected from the east and west side of the Siang river. The clade 1 that represented Himalayan red panda was formed by the inclusion of samples originated from the north West Bengal, Sikkim, and central and Western Arunachal Pradesh and South Tibet, located in the west of Siang river. While, clade 2 stood to Chinese red panda, and represented samples originated from Dibang valley of eastern Arunachal Pradesh, India and Southwest China, in the east of Siang river. This study provides pragmatic genetic evidence and demonstrates Siang river as a potential boundary of species divergence in red panda by contributing samples from Indian Himalayan Region. We suggest being associated with diverse habitats, threats and transboundary distribution, both species of red panda require regional as well as transboundary level conservation initiatives and multilateral cooperation for a species survival plan.

A Comparative Heavy Mineral Study of the Cenozoic Sediments of Assam and Siwalik Foreland Basins, Northeast Himalaya

Heavy mineral assemblages of sedimentary units are used as an essential provenance constraint. The sedimentary successions of the southern Assam and Siwalik foreland basins were analyzed for their heavy mineral suits and provenance determination. Heavy minerals were identified using the petrological microscope, X-ray Diffraction (XRD) and Electron Probe Micro Analyzer (EPMA) analyses. The study demonstrates that heavy minerals weight percentage in the southern Assam basin is lower than that of the northeast (NE) Siwalik basin. In the Assam basin, the weight percentage of dense minerals varies from 0.08% to 1.31%; however, in the Siwalik sediments, it varies from 2.27% to 5.78%. The relative dominance of opaque minerals over transparent heavy minerals is observed throughout the Cenozoic rocks of Assam basin, except for the Tipam unit. At the same time, the Siwalik basin successions show a low percentage of opaque minerals and high amount of non-opaque heavies. Detritus in the Assam basin reveals a distinct change in the occurrence of heavy mineral assemblages (amphibole, aluminosilicates, staurolite and a high percentage of epidote, pyroxene and sphene) in the Mio-Pliocene unit (Tipam sandstone) compared to Barail and Surma older units, implying involvement of an additional orogenic source. This study suggests that NE Siwalik sediments were primarily derived from Himalayan rocks of the Siang window, while heavies in the detritus of the southern Assam basin exhibits a mixed provenance both from the eastern Himalaya, chiefly from Dibang and Lohit valley and Indo-Burman-Ranges (IBR).

Performance of horticultural crops in Arunachal Pradesh with special reference to West Kameng District

The Arunachal Pradesh region is one of the richest reservoirs of genetic variability and diversity of different crops i.e. various kinds of fruits, different vegetables, spices, ornamental plants and also medicinal and aromatic plants. The diversity for horticultural crops of this region has mainly been managed by local farmers, often women. Considerable diversity exists among the regional horticultural species including variation in plant type, morphological and physiological characteristics, reactions to diseases and pests, adaptability and distribution. Apart from the nutritional value, many regional horticultural crops are used for medicinal purposes and income generating source in the rural areas. The Arunachal Pradesh of States constitutes the District of West Kameng, Tawang, East siang, East Kameng, Papum Pare, Lower Subansiri, Kurang Kumey, Upper Subansari, West siang, East siang, Upper siang, Dibang valley, Lower Dibang valley, Lohit, Anjaw, Changlang and Tirap. The raining season in this region generally commences from March and lasts till the end of September. Diverse agro–climate condition, fertile soils and abundance of rainfall offer immense scope for development in the horticulture sector. This paper is a humble effort at bringing fort the states of production of the horticultural crops of the Arunachal Pradesh, particularly West Kameng. The exportable surplus and its potentialities is also discus as well as the potential for the National/ International markets is also found out along with the problems of support for export promotion, transport facility etc.

Thermochronological insights into the thermotectonic evolution of Mishmi hills across the Dibang Valley, NE Himalayan Syntaxis

Eastern Himalayan Syntaxis (EHS) that forms the northeastern termination of the Himalaya consists of three broad zones; Namche Barwa massif, Siang antiform and Mishmi Hills. The present work provides new in-situ apatite fission track (AFT), zircon (U-Th)/He (ZHe) and 40Ar/39Ar multi-thermochronometric ages across the Dibang valley in the Mishmi hills. The study constrains the structure, emplacement time of major thrusts and initiation of Lesser Himalayan Duplex (LHD). Biotite 40Ar/39Ar ages of the Lohit batholith suggest late Oligocene cooling. ZHe ages indicate late Miocene (~8–9 Ma) foreland directed duplex initiation in the Dibang valley. The AFT cooling ages (~5–3 Ma) suggest LHD continued into Mid Pliocene. Confined track lengths and thermal modelling indicate that the northeastern samples from the study area underwent a phase of rapid exhumation around 10 Ma, followed by slow cooling. It is in contrast to the south-western samples from the Dibang valley that have cooled and uplifted rapidly only after around 4 Ma, due to accelerated phase of LHD. Our 3D thermo-kinematic modelling of the data indicates less mass removal around Hunli than other parts of Dibang valley. The result is in contrast to previously estimated ~16 km uplift near Hunli and mass removal. AFT ages from the Hunli window indicate that the region witnessed modest uplift of ~4–5 km since ca. 4 Ma. Brittle duplexing of the lower LHS at Hunli and Mayodia caused the warping of the overlying litho-units. Hunli duplex alone accommodated ~86% of the total shortening.

Successful agricultural trainees- Some cases from lower dibang valley, Arunachal Pradesh

Successful agricultural trainees- Some cases from lower dibang valley, Arunachal Pradesh

Impatiens Ashihoi, a new species of Balsaminaceae from Dibang Valley of Arunachal Pradesh, India

Impatiens ashihoi Gogoi & Borah (Balsaminaceae), a new species from the Lower Dibang valley district in Arunachal Pradesh, India, is described and illustrated. The new species is similar to I. bracteolata Hook.f. but differs in having horn-like stipular glands at the base of petiole, leaves lanceolate to elliptic lanceolate, ventral side of leaf purplish-green with prominent white midrib, prominent awn or appendage in the apex of bract and lateral sepals, awn or appendage in the mouth of lower sepal. It is also similar to I. drepanophora Hook.f. but differs in having horn like stipular glands at the base of petiole, dorsal side of leaf wine red in colour, ventral side of leaf purplish-green with white midrib, lamina lanceolate to elliptic lanceolate.

Stable (δ13C and δ15N) Isotopes and Magnetic Susceptibility Record of Late Holocene Climate Change from a Lake Profile of the Northeast Himalaya

Abstract This study aims at reconstructing paleovegetation history in the northeast Himalaya during the past 2700 yrs using a 100 cm long sedimentary section selected near Anini village, Dibang valley, Arunachal Pradesh (India). Stable carbon and nitrogen isotopic composition (δ13C and δ15N); and total organic carbon (TOC) and total nitrogen (TN) content in organic matter as well as magnetic susceptibility were determined. Results obtained show a strong correlation between TOC-TN indicating similar source for organic matter. δ13C and TOC/TN ratio throughout the stratigraphic unit seems to be poorly correlated which suggests that the primary carbon isotope signatures are preserved in the sedimentary environment. Overall, δ13C values of the organic matter in the section vary in the range from −23.9 to −21.2 ‰ which is typical of mixed C3-C4 plants.. A distinguishable increasing trend in δ13C during 2700 to 1300 yrs indicates change in vegetation pattern from C3 to C4 plants due to significant climate change from wetter to drier conditions. After 1300 yrs δ13C values decrease rapidly by 1.3‰ and suggest increasing abundance of C3 plants in wetter climatic condition. The relatively small variation in δ13C values in the upper part of the section during 1200 yrs to present suggest a stable climatic condition.

Impatiens adamowskianasp. nov. (Balsaminaceae) from Arunachal Pradesh, northeast India

Impatiens adamowskiana from the lower Dibang valley district of Arunachal Pradesh, northeast India, is newly described and illustrated. The species is characterized by quadrangular winged stem, sessile leaves with attenuate base, 10–17 pairs of lateral veins, up to 20 cm long inflorescence with up to 30 flowers, red flower, navicular lower sepal, and upcurved spur.

Trend analysis of annual and seasonal rainfall to climate variability in North-East region of India

Global warming, climate change and its consequences are major threat for the global agriculture. The agriculture in the North-East region of India is supposed to more in danger due to its topographic features. Agriculture in the state of Arunachal Pradesh is dependent on rainfall and variability in rainfall due to climate change is expected to threaten the food production in future. This study examines the impact of climate change on rainfall using the trend analysis technique for the four districts of Arunachal Pradesh. For this purpose temporal trends in annual and seasonal rainfall were detected using nonparametric Mann-Kendall test at 5% significance level. The daily time series rainfall data for the period 1971-2007 were analyzed statistically for each district separately. The results of Mann Kendall test showed decreasing trend in annual mean rainfall in east Siang, upper Siang and lowers Dibang valley and no trend in the west Siang district over the period of 1971-2007. In case of east Siang, upper Siang and lower Dibang valley districts, decreasing trend of rainfall was observed in the post monsoon season with slope magnitude of 3.01 mm/yr, 3.32 mm/yr and 3.95 mm/yr respectively. Decreasing pattern of rainfall in post monsoon season may affect the vegetable and fruit production in the winter season.

Assessingjhum-induced forest loss in Dibang valley, Arunachal Himalayas — A remote sensing perspective

There has been a significant advancement in the application of remote sensing from various space altitudes for inventorying and monitoring ofjhum (shifting) cultivation associated forest loss. The dynamic nature ofjhum system, complex physiography, small size of individualjhum plots and their discontinuous nature of distribution, highly heterogeneous vegetation and ever-changing atmospheric condition in the Arunachal Himalaya posses a great challenge to local flora and fauna. Indian Remote Sensing (IRS)-1C/1D LISS-III data were used to classify the current and abandonedjhum areas in Dibang valley district. The amount of area occupied by current and abandonedjhum corresponds to 199.34 km2(1.53%) and 225.40 km2(1.73%) respectively. Field data were collected following stratified random sampling method to gather information on plant community occurring in abandonedjhum cultivated areas. It was observed that only nine species out of 45 contribute to 50% of the important value index (IVI). Of the 45 species, 7 species (15.56%) have been found to be endemic to Eastern Himalayas. Population inducedjhum cultivation has led to deforestation, biodiversity loss, increased surface soil erosion, and sedimentation of water bodies in this area. The potential use of satellite-derived maps can best be used for better management and land use planning.