A report of Siwalik forest around Letang Raja-Rani wetland, Morang, eastern Nepal

Species composition, phytosociological status and soil characteristics of Siwalik forest occurring around Raja-Rani wetland, Letang municipality, eastern Nepal was studied. A total of 47 tree species belonging to 40 genera and 26 families were reported. Dominant and co-dominant trees were Shorea robusta (IVI=133.4) and Schima wallichii (IVI=70.6), respectively. In the forest total tree density, basal cover area, seedling density, fallen dead density and dead standing density were 378.4 trees ha-1, 163.7 m2 ha-1, 105250 individual ha-1, 4 trees ha-1 and 1.6 trees ha-1, respectively. Irregular girth class distribution and high stump density (136.8 tree ha-1) denote disturbance. Soil physicochemical characteristics were: acidic soil (pH 4.8), moisture (12.5%), water holding capacity (50.05%), bulk density (1.17 g cm-3), porosity (0.55%), humus (8.6%), organic carbon (0.52%), nitrogen (0.1%), phosphorus (33 kg ha-1), and potassium (300 kg ha-1). Regulating human encroachment to ensure natural regeneration of species to maintain the viability of the Letang Raja-Rani wetland site and integrity of the local ecosystem is strongly recommended.

Fish community structure along altitudinal gradients with relation to environmental variables in Ratuwa River of Eastern, Nepal

Studies on fish community structure along altitudinal gradients of rivers are lacking in Nepal. This study was carried out to gauge the fish diversity and composition along elevational gradient in Ratuwa River. The altitudinal gradient varies between 70 m to 1300 m. Fish samples were collected based on habitat representativeness from April (spring) 10-18, July (summer) 10-18, October (autumn) 10-18, 2020 and January (winter) 10-18, 2021. A total of 3447 specimens representing 4 orders, 14 families and 36 species were identified. Both fish diversity and abundance of studied ichthyofauna vary with altitudinal gradient. The present study affirmed that fish species of Opsarius bendelisis, Schistura multifasciatus, Garra annandalei, Brachydanio rerio, Aspidoparia morar, and Schistura scaturigina are the major contributory species (>1%) for both space and time spectrums. Fish community structure testing for both to space and time showed significant difference in spatial spectrum (R=0.72, P<0.01) but no significant difference in temporal variation (R=-0.034, P>0.05). The present results hinted that fish assemblage structure varied significantly from low to high elevations, altitude, water temperature, water velocity, dissolved oxygen and pH was found as major influential factors (P<0.05) for species distribution.

Application of Water Quality Index (WQI) for groundwater quality assessment of Biratnagar, Nepal

This present hydrological study assessed the groundwater quality of Biratnagar Metropolitan by the application of Water Quality Index (WQI). It has been determined on the basis of analyzed groundwater samples for some important physicochemical parameters such as pH, turbidity, electrical conductivity (EC), dissolved oxygen (DO), free carbon-dioxide (FCO2), bicarbonate (HCO3), total hardness (TH), phosphate (PO4-P), nitrate-N (NO3-N), arsenic (As), and fluoride (Fl) collected from 110 representative tube wells during post-monsoon period of 2015. The status of fluoride was below detectable level (BDL) in all the analyzed groundwater samples. The WQI for these samples ranged from 84.54 to 403.14. The high value of WQI has been found mainly due to the higher values of turbidity, FCO2 and arsenic in the groundwater. The results of study have been used to recommend models for predicting water quality. The classification of water quality on the basis of WQI value have been found to be good water (18.18%), poor water (59.09%), very poor water (13.64%) and unsuitable for drinking (9.09%). The result of the study suggests that the groundwater of the area needs some degree of treatment before consumption, and it also needs to be protected from the threat of contamination. The groundwater is one of the major source of drinking water as well as for irrigation in study area.

Population status and breeding ecology of Black Kite Milvus migrans (Boddaert, 1783) in Pokhara Valley, Nepal

The present study attempted to provide basic knowledge on population status, breeding success and general behaviours of Black kites in the Pokhara Valley of Nepal. Nesting and roosting sites were directly observed to count the bird in the fields during the study period from December 2019 to May 2020. A total of 308 individuals of Black kites were recorded. The highest and least number was recorded in February (n=67) and May (n=31) respectively. The breeding success was found to be 47.22%. The average height, girth and canopy cover of the nesting tree were found at 16.59m, 2.23m and 63.30% respectively. About 67% of nests observed were found active during the breeding season. The Spearman rank correlation coefficient showed a perfect positive relationship between the number of chicks and the number of the nest (r = 1). Bombax ceiba and Dalbergia sissoo were the trees on which the maximum number of nests were observed.

Species diversity of macrophytes in Jagadishpur Reservoir, Kapilvastu District, Nepal

The present research was conducted for quantitative study and diversity analyses of aquatic macrophytes dwelling littoral zone of Jagadishpur reservoir, Kapilvastu district in three seasons, as winter (December), summer (April), and rainy (August). Altogether 58 species of macrophytes were recorded in study site, of which highest number of species (54) was occupied by angiosperms followed by three species of pteridophytes and one species of alga. These macrophytes varied in different morphological groups, viz., emergent, submerged, and rooted-floating leaf type. Maximum number of species were represented by emergents (39) followed by rooted-floating leaf type (12) and submerged (7) macrophytes. There was distinct seasonal variation in the distribution of macrophytes: based on importance value index, Nelumbo nucifera (IVI = 22.87), Scripus sp. (IVI = 28.01), Ipomoea carnea (IVI = 24.67) and Typha angustifolia (IVI = 29.01) were dominant in the winter; Nelumbo nucifera (IVI = 20.05), Cynodon dactylon (IVI = 20.07) and Ipomoea carnea (IVI = 21.17) were dominant in the summer and Nelumbo nucifera (IVI = 23.8) and Scripus sp. (IVI =25.56) were dominant in the rainy season. The highest species diversity (H’) of macrophytes was observed during summer (3.451), followed by rainy season (3.135) and winter (3.008). The luxuriant growth of aquatic macrophytes evidenced the highly productive nature of the lake, while the dominance of emergents among the growth forms indicates the encroachment of littoral vegetation, indicating a successional trend toward marsh meadow.

Comparative leaf morphology and anatomy on ten taxa of Calycanthaceae Lindl. (Laurales)

The comparative leaf morphology and anatomy of ten species of family Calycanthaceae have been studied. Leaf anatomy is very comparable to each other in cell shape and their arrangement. Collected leaves were preserved in FAA and alcohol series were applied for LM and SEM. The layer of epidermis is two in Idiospermum and one in rest of other genera. The structure of vascular bundle is V-shape in Sinocalycanthus and Calycanthus whereas U-shape in Idiospermum and Chimonanthus. The density of trichome is higher in Calycanthus than other genera. The presence of trichome, stomata, epidermal layer, density of trichome and stomata, and leaf surface are represented the distinction among the genera. The adaxial surface of Idiospermum and Sinocalycanthus are smooth whereas of Calycanthus and Chimonanthus are rough. The crystals are present in Calycanthus, Sinocalycanthus and Chimonanthus whereas absent in Idiospermum. The shape of the vascular bundle, density of trichome, epidermal layer, and crystals play important role in the phylogenetic relationship of Calycanthaceae.

Human-Elephant interactions and associated damage in the northern transboundary areas of Bangladesh

We have studied human-elephant interactions in the northern transboundary of Bangladesh and estimated the scale of associated damage due to the negative interaction by visiting conflict area, performing focus group discussions key informant interviews and using secondary data sources. Around 70-80 non-resident elephants regularly intruded to the study area through the international border fence using several trespassing points and engaged in conflicts with frontier villagers. We discussed the nature and scale of conflict and the financial losses due to the conflict. Besides severe casualties in both ends, the enumerated economic loss was USD 1,171, 665 in 2013 and 2014 due to the damage to cropland, houses and properties, trees and orchards. We have identified major human-elephant conflict (HEC) zones adjacent to the border fence through spatial analysis with different level of intensity. Appropriate human-elephant conflict mitigation measures such as habitat improvement and management, monitoring of elephant population, alternative income generation, awareness programs for the local people and working together with India regarding this issue is a timely and urgent need for Bangladesh

An assessment of the Human-Elephant conflict in Sapahi and Kakadi Village of Kolhabi Municipality, Bara, Nepal

This study aims to assess the trend, extent, and impact of Human-Elephant conflict (HEC) in Sapahi and Kakadi villages of Bara district. Direct field observation, Household Survey (HHs), Focus Group Discussions (FGDs), and Key Informant Interview (KII) were carried out during November and December 2016 where 11 wards were selected purposively from two village and 50 households from each village. Also, 12 KII and one FGDs from each ward were performed. SPSS 20.0, and MS Excel 2016 were used to calculate mean, percentage, frequency count, and chi-square test was used to determine the variation in people’s perception towards wild Elephant conservation. The total average damage of paddy per year per HHs was 834.1 kg followed by wheat 153.7 kg, and mustard 2.12 kg. The economic value of average annual crop damage per year per HHs accounted for NRs. 22669.70. Among total HHs, 84% of the respondents said that the trend of crop damage is increasing, 10% found no differences in crop damage, and remaining 6% said decreasing. During the last 5 years, 7 people were injured, and 6 were killed. The lighting fire, beating drum, and making noise were the local techniques used by all the respondents to chase away elephant for the mitigation of HEC. The farmers also guard their fields at night time. 60% of the respondents are positive towards elephant conservation and remaining 40% seems no significance for conservation. The compensation scheme for crop damage should be properly implemented in the study area to minimize the HEC. A sustained conservation education program especially focusing on female, farmers, and nomads are recommended to conserve wild elephants, and their habitat.

Relationships between environmental conditions and fish assemblages in the Lohore River of Dailekh, Western Nepal

The Lohore River is one of the important riverine ecosystems of Dailekh which support diverse aquatic communities. The present study was carried out to assess the fish diversity status with relation to environmental conditions in both to space and time. The survey was conducted at three different sampling stations in three different seasons. For the fish sampling, two cast nets of different mesh sizes were used, one having large mesh size of 2 cm, 6 m diameter and 6 kg weight and another having mesh size of 0.5 cm, 3 m diameter and 2 kg weight. Moreover, drag net and gill net were also used to collect the fish samples. A total of 11 fish species belonging to 2 orders, 3 families and 7 genera. Results from the similarity percentage analysis (SIMPER) suggested that fish species of Puntius gelius, Schizothorax plagiostomus, Tor chelynoides and Schistura sovana were major contributing species each contribute more than 9%. An analysis of similarity (ANOSIM) pointed that fish community structure in the Lohore River differ in spatial scale (p<0.01) but not in temporal scale (P>0.01). Water temperature, dissolved oxygen and water velocity was found as influential factors for fish species distribution.

The morphohistology and fine anatomy of the olfactory organ in pabda catfish, Ompok bimaculatus (Bloch, 1794)

The organization of the olfactory system in Ompok bimaculatus (Siluriformes: Siluridae) were investigated by histological and ultrastructural analysis. The nasal chamber was totally engrossed by a boat shaped elongated olfactory rosette with numerous lamella. Histomicroscopically, each lamella was comprised of central core bounded on both sides by the cellular elements of olfactory epithelium. The central core was composed of thick connective tissue, nerve fibres and blood capillaries. The cellular components of the olfactory epithelium were identified based on their staining vigour, architecture, structural characteristics and surface features. The sensory epithelium contained morphologically recognizable ciliated, microvillous and rod receptor neurons. Labyrinth cells, scattered lymphatic cells, secretory mucous cells, stratified epithelial cells bearing microfolds and condensed ciliated supporting cells were observed in the indifferent epithelia. The basal cells were submerged in the deeper zone of mucosa above the basal lamina. Different sensory and nonsensory cells of the olfactory lining were associated with chemical stimulation of the fish studied. This species acquires a well developed olfactory sense for exploring the aquatic environment and able to determine the chemical changes in the surroundings.