Abstract
This paper identifies and documents the plant biodiversity of western Chitwan, Nepal. Specifically, our attention was focussed on the plants of forests, grasslands and common lands based on our “Reciprocal Relation of Population and Environment Study Project” conducted during January-April 1996. This species-diversity of trees, shrubs and herbaceous flora was recorded from 117, 117, and 1049 sampling quadrats of 10×10, 3×3 and 1×1 m2, respectively. The flora of our study plots contains 236 species that belong to 191 genera and 66 families. Of 236 species of plants, 119, 113, 59, 35 and 119 species were recorded from Tikauli forest, National Park forest, forests along the Narayani river, grasslands of National Park and common lands of the western Chitwan, respectively. Dicotyledons represent 184 (77.97%) species of the total flora species followed by monocotyledons (46 spp., 19.49%) and ferns (6 spp., 2.54%), respectively. The five largest families are Leguminosae (38 spp.), Poaceae (27 spp.), Asteraceae (22 spp.), Rubiaceae (10 spp.), and Scrophulariaceae (9 spp.). Hedyotis, Grewia and Lindernia, each with 4 spp., are the most speciose genera in the flora.
Keywords: biodiversity, flora, species-list
Introduction
In the Chitwan district of Nepal, there is a high flow of migrants from the neighboring hill districts of Nepal. The increasing population of this district is largely dependent on natural plant resources to provide resources such as fuel, fodder and timber. As a result of high pressure on the forests and common lands, a number of changes have occurred including deforestation and the conversion of natural habitats into man-engineered habitats such as cultivated fields, lawns, school grounds, road ways, canal ways, etc. Nepal’s poor economic condition (42% below proverty line) and low literacy rate (39.6%) combined with the lack of environmental education and awareness, result in humans being a factor responsible for the reduction of biological resources and natural ecosystems. In due course, it will be no wonder to find some of the plant species already depleted, others dangerously near depletion from the area, and vast invasion of new weeds in both natural and man-made habitats. We do not have an exact account of the plant species present in this district. Under this circumstances it is important to understand what plant species are prevalent the Chitwan district and make aware the authorities and communities so that they can protect and preserve plant biodiversity and diversified habitats.
Plant species play a vital role in maintaining the ecological balance of nature, therefore systematic floristic inventory and ecological studies are of vital importance Previous research on the flora of agricultural fields (Gupta et al, 1977; Dangol and Gurung. 1988; Dangol, 1990a and 1990b) and forest and grasslands in the Chitwan district (Lehmkuhl 1994; Dangol et al, 1995; Joshi and Jha, 1995). Keeping in mind the importance of ecological study to understanding the reciprocal relations between environment and population, we have gathered information on plant species, their population and cover values and other physiographic data from research plots in western Chitwan. In this paper, we present an inventory of plant species and analyze the floristic diversity in relation to different habitats of our research plots.
Study Area
The portion of the Chitwan district under study lies in the southernmost part of the Narayani zone in central Nepal. It extends between 83°55′ – 85°37′ E longitude and 27°21′ – 27°46′ N latitude covering an area of about 2510 km2 that is nearly 30% of the Narayani zone. Makawanpur district in the east, Nawalparasi and Tanahun districts in the west, Gorkha district in the north and the Someshwor range (Churia hill) in the south surround this district. The Mahabharat range and the Churia hills surround the entire land of this district, which is called Bhitri Madhesh (Dun Valley or Inner Terai). This district enjoys a subtropical climate with fertile soils suitable for growing a variety of plants including crops.
Materials and Methods
In order to assess the floristic inventory of plants present in this area, 265 research (quadrat) plots representing forests (117), grasslands (10) and common lands (138) in the different locations in the district were identified (Map 1). The forests of present study are Tikauli jungle (Block A), Royal Chitwan National Park (Block B). and forests along the Narayani River (Block C). Block A is situated in the southern east boundary of the study site and extends between the East-West Highway in the north and the Rapti River in the south. Block B is the southern boundary of the study area. It expands between the Jarneli post in the east to the confluence of the Reu khola and the Rapt River in the west. Block C includes the forests that expand along the south edge of the Narayani River, from the East-West Highway to the confluence of the Narayani arid Rapti Rivers is the northwest boundary of the study area. This block includes Nagarban (4 sample plots); Jhanjhaneban (7 plots); Gobreni (also called Majhuwa) ban (5 plots); and Kalaban (5 plots) were selected. The grassland plots were located between the Dhruba post and Sukhibar post of the Royal Chitwan National Park (Block B). The common lands refer to the lands used for common purposes of the residents of the western Chitwan. These represent different land use categories such as plantation areas, flood affected areas, common grazing lands, Baradavar/Tikauli grazing and grass cutting areas, School grounds and airport areas, Pokhari (ponds) and Ghole (marshy land) aeas, roadways, and canal ways.
Map 1.
Flora Plots Locations in Western Chitwan, Nepal
For the present study, three types of sampling units (quadrats) were used: (a); 10 × 10 m2 for trees and woody climbers, (b) 3×3 m2 for shrubs and saplings of the trees, and (c) 1 × 1 m2 for herbs and seedlings of trees and shrubs. Five 1 m2 quadrats were positioned in each of the largest quadrat (10×10 m2) in forests and grasslands and three 1 m2 quadrats in each 10 × 10 m2 or 1 × 25 m2 sampling plot in the common lands. The sampling plot 1 × 25 m2 was determined for the canal ways and roadways. The plot size was 10 × 10 m2. Frequencies of sampling quadrats in the particular study areas are given below (Table 1). Detail procedure for making sampling plots has been described by Chhetri (1996), and Richter and Chhetri (1997).
Table 1.
Size and number of quadrats studied in different research sites in west Chitwan, Nepal.
| Research Site | Quadrat Size | ||
|---|---|---|---|
| 10 × 10m2 | 3 × 3m2 | 1 × 1m2 | |
| Tikauli forest | 62 | 62 | 310 |
| National Park forest | 34 | 34 | 170 |
| National Park grassland | 10 | - | 50 |
| Forest along Naryani river | 21 | 21 | 105 |
| Common lands | 138 | - | 414 |
| Total | 265 | 117 | 1049 |
Plant identification
The plant specimens were identified with the help of illustrated manuals and flora books. The identification was further conformed matching with the herbarium specimens in National Herbarium and Plant Laboratories of the Department of Plant Resources, Godawari. Some specimens are identified by local names only. All the voucher specimens collected during the present study are housed in the Herbarium of the Department of Agricultural Botany, Institute of Agriculture and Animal Science, Rampur. Chitwan, Nepal.
Result and Discussion
Species-diversity
Our species-list enumerates 236 plant species belonging to 66 families and 191 genera (Appendix I). This indicates the richness of the floristic diversity within the research plots. These species comprise 184 Dicotyledons (77.97%), 46 Monocotyledons (19.49%) and 6 fern and their allies (2.54%) (Table 2) The Leguminosae (34 spp.), Poaceae (26 spp.) and Asteraceae (21 spp.) are the most prevalent families in floristic composition (Table 3), in terms of numbers of species and genera. Those families are followed by the Acanthaceae, Labiatae, Rubiaceae Scrophulariaceae, Euphorbiaceae, Cyperaceae and Verbenaceae. The rest of the families contain less than 5 species.
Appendix I.
Species-list of the plants of western Chitwan, Nepal, January-April, 1996 Blocks: A (Tikauli forest), B (National Park), C (Forests along the Narayani river), GL (Grassland of National Park), and CL (common land). (x= presence in a particular research block)
| Family names | Botanical names | Local names | A | B | C | GL | CL |
|---|---|---|---|---|---|---|---|
| Acanthaceae | Barleria cristata L. | Kuro | x | x | x | ||
| Acanthaceae | Hemigraphis hirta (Vahl) T. Anders. | x | x | ||||
| Acanthaceae | Hygrophita polysperma (Roxb.) T. Anders. | x | |||||
| Acanthaceae | Justicia quinqueangularis Koenig ex Roxb. | x | |||||
| Acanthaceae | Justicia sp. | Bisaune jhar | x | ||||
| Acanthaceae | Lepidagathis incurva Buch.-Ham ex D. Don | Bankuro | x | ||||
| Acanthaceae | Nelsonia canescens (Lam.) Spreng. | x | |||||
| Acanthaceae | Rungia parviflora (Retz.) Nees | Saraudi | x | x | x | x | x |
| Amaranthaceae | Achyranthes aspera L. | Datiwan | x | x | x | ||
| Amaranthaceae | Alternanthera sessilis (L.) DC. | Bhiringi jhar | x | ||||
| Anacardiaceae | Buchanania latifolia Roxb. | Bhalayo | x | ||||
| Apiaceae | Centella asiatica (L.) Urb. | Ghodtapre | x | x | x | x | |
| Apiaceae | Hydrocotyle sibthorpioides Lam. | Sano ghodtapre | x | x | x | ||
| Apiaceae | Oenanthe javanica (Blume) DC. | x | x | ||||
| Apocynaceae | Holarrhena pubescens (Buch.-Ham.) Wall. ex G. Don | Dudhkhirro | x | x | |||
| Apocynaceae | Trachelospermum lucidum (D. Don) K. Schum. | Salikal | x | ||||
| Apocynaceae | Vallaris solanacea (Roth) Kuntze | Dudhe lahara | x | x | |||
| Araceae | Pistia siratiotes L. | Bankovi | x | ||||
| Arecaceae | Phoenix humilis Royle ex Baccari. | Dhotipate/Thakal | x | x | |||
| Asclepiadaceae | Calotropis gigantea (L.) Dryand | Aank | x | ||||
| Asclepiadaceae | Gongronema nepalense (Wall.) Deene | x | |||||
| Aspidiaceae | Tectaria macrodonta (Fee) C. Chr. | Kali neuro | x | ||||
| Aspidiaceae | Thelypteris auriculata (J. Smith) K. Iwatsuki | Bishkoche | x | x | x | x | x |
| Asteraceae | Ageratum conyzoides L. | Gandhe (Seto) | x | x | |||
| Asteraceae | Ageratum houstonianum Mill. | Gandhe (Nilo) | x | x | x | x | x |
| Asteraceae | Artemisia dubia Wall. ex Besser | Titepati | x | ||||
| Asteraceae | Bidens pilosa L. | Kalo kuro | x | ||||
| Asteraceae | Blumea laciniata DC. | Thulo mulapate | x | x | x | x | |
| Asteraceae | Blumea sp. | Thulo mulapate | x | ||||
| Asteraceae | Blumeopsis flava (DC.) Gagnep. | Toriganda | x | x | |||
| Asteraceae | Caesulia axillaris Roxb. | Thuk jhar | x | ||||
| Asteraceae | Cirsium arvense (L) Scop. | Gainda kande | x | x | x | ||
| Asteraceae | Conyza leucantha (D. Don) Ludlow & Raven | Mulapate | x | ||||
| Asteraceae | Eclipta prostrata (L.) L. | Bhringraj | x | x | x | ||
| Asteraceae | Elephantopus scaber L. | Thinko | x | x | |||
| Asteraceae | Emilia sonchifolia (L.) DC. | Mulapate | x | ||||
| Asteraceae | Eupatorium odoratum L. | Banmara | x | x | |||
| Asteraceae | Gnaphalium purpureum L. | Boki jhar | x | ||||
| Asteraceae | Inula rubricaulis (DC.) C. B. Clarke. | Kan pate | x | x | |||
| Asteraceae | Ixeris polycephala Cass. | Dudhe jhar | x | x | |||
| Asteraceae | Launaea aspleniifolia (Willd.) Hook. f. | Sano mulapate | x | x | x | x | |
| Asteraceae | Spilanthes uliginosa Swarts | Marethi | x | ||||
| Asteraceae | Synedrella nodiflora Gaertn. | Pahenle jhar | x | ||||
| Asteraceae | Tridax procumbens L. | Putali jhar | x | ||||
| Asteraceae | Vernonia cinerea (L.) Less. | Jhurjhure | x | x | x | x | |
| Asteraceae | Xanthium strumartum L. | Bhende kuro | x | x | |||
| Barringtoniaceae | Careya arborea Roxb. | Kumbhi | x | ||||
| Bombacaceae | Bombax ceiba L. | Simal | x | x | x | ||
| Boraginaceae | Heliotropium strigosum Willd. | Hanthi sunde | x | ||||
| Boraginacese | Trichodesma indicum (L.) R. Br. | Gerguj | x | ||||
| Burseraceae | Garuga pinnata Roxb. | Dabdabe | x | x | |||
| Campanulaceae | Campanuia pallida Wall. | Ghante jhar | x | ||||
| Chenopodiaceae | Chenopodium album L. | Bethe | x | ||||
| Combretaceae | Terminalia alata Heyne ex Roth | Saj | x | x | |||
| Combretaceae | Terminalia bellirica (Gaertn.) Roxb. | Barro | x | x | |||
| Combretaceae | Terminalia chebula Retz. | Harro | x | ||||
| Commelinaceae | Commelina benghalensis L. | Bankane/Jangali kane | x | x | x | x | |
| Commelinaceae | Commelina sp. | Jangali kane | x | ||||
| Convolvulaceae | Evolvulus nummularius (L.) L. | Badampate jhar | x | x | |||
| Cordiaceae | Ehretia laevis Roxb. | Dhatrung | x | x | x | ||
| Cornaceae | Swida oblonga (Wall.) Sojak | Latikath | x | x | |||
| Cucurbitaceae | Momordica charantia L. | Ban kareli | x | ||||
| Cucurbitacęae | Solena heterophylla Lour. | Gol kankari | x | x | |||
| Cyperaceae | Cyperus iria L. | Chhate mothe | x | ||||
| Cyperaceae | Cyperus sp. | Mothe | x | x | x | x | |
| Cyperaceae | Eleocharis pellucida Presl | Jwane jhar | x | ||||
| Cyperaceae | Kyllinga brevifolia Rottb. | Dalle mothe | x | ||||
| Cyperaceae | Pycreus flavidus (Retz.) T. Koyama | Chiure mothe | x | ||||
| Cyperaceae | Schoenoplectus juncoides (Roxb.) Palla | Suire jhar | x | ||||
| Dilleniaceae | Dillenia pentagyna Roxb. | Tantari | x | x | |||
| Dioscoreaceae | Dioscorea bulbifera L. | Ban tarul | x | x | |||
| Dioscoreaceae | Dioscorea deltoidea Wall. ex Griseb. | Ban tarul | x | x | x | ||
| Dioscoreaceae | Dioscorea hamiltonii Hook. f. | Ban tarul | x | ||||
| Dipterocarpaceae | Shorea robusta Gaertn. | Sal | x | x | |||
| Equisetaceae | Equisetum debile Roxb. ex Vaucher | Hadjorni/Aankhle jhar | x | x | x | x | |
| Euphorbiaceae | Antidesma acidum Retz. | Archal | x | x | |||
| Euphorbiaceae | Bridelia retusa (L.) Spreng. | Gayo/Lahare gayo | x | ||||
| Euphorbiaceae | Euphorbia hirta L. | Dudhe jhar | x | x | |||
| Euphorbiaceae | Euphorbia parviflora L. | Sano dudhe jhar | x | ||||
| Euphorbiaceae | Mallotus philippensis (Lam.) Muell -Arg. | Sindure | x | ||||
| Euphorbiaceae | Phyllanthus emblica L. | Amala | x | ||||
| Euphorbiaceae | Phyllanthus urinaria L. | Bhuiamala | x | x | x | ||
| Euphorbiaceae | Trewia nudiflora L. | Vellar | x | x | x | ||
| Gentianaceae | Canscora decussata (Roxb.) Schult & Schult.f. | Seto phule jhar | x | ||||
| Labiatae | Acrocephalus indicus (Burm. f.) Kuntze | Lerui jhangi (D) | x | ||||
| Labiatae | Colebrookea oppositifolia Sm. | Dhurseli | x | x | |||
| Labiatae | Hyptis suaveolens (L.) Poit. | Jangali silam | x | x | |||
| Labiatae | Leucas plukenetii (Roth) Spreng. | Gumpate | x | ||||
| Labiatae | Ocimum basilicum L. | Babari | x | x | |||
| Labiatae | Pogostemon benghalensis (Burm.f.) Kuntze | Rudilo | x | x | x | ||
| Labiatae | Rabdosia ternifolia (D. Don) Hara. | Bhimsenpati jhar | x | ||||
| Lauraceae | Litsea chartacea (Wall. ex Nees) Hook. f. | x | |||||
| Lauraceae | Litsea monopetala (Roxb.) Pers. | Kutmiro | x | x | x | x | |
| Leeaceae | Leea crispa van Royen ex L. | Guithe Padari/Padari | x | x | |||
| Leeaceae | Leea macrophylla Roxb. ex Hornem. | Galeni | x | x | |||
| Leguminosae | Acacia catechu (L.f.) Willd. | Khayer | x | ||||
| Leguminosae | Acacia pennata (L.) Willd. | Ararikanda | x | x | |||
| Leguminosae | Atylosia scarabaeoides (L.) Benth. | Bangahat | x | ||||
| Leguminosae | Bauhinia malabarica Roxb. | Amili | x | ||||
| Leguminosae | Bauhinia vahlii Wight & Arn. | Bhorla | x | ||||
| Leguminosae | Butea monosperma (Lam.) Kuntze | Palans | x | ||||
| Leguminosae | Caesalpinia bonduc (L.).Roxb. | Bhaise kanda | x | ||||
| Leguminosae | Cassia fistula L. | Rajbrikchya | x | ||||
| Leguminosae | Cassia occidentalis L. | Bhaise tapre | x | ||||
| Leguminosae | Cassia tora L. | Tapre jhar | x | x | |||
| Leguminosae | Codariocalyx motorius (Houttyn) Ohashi | x | |||||
| Leguminosae | Crotalaria prostrata Rottb. ex Willd | Chhinchhine baja | x | x | x | ||
| Leguminosae | Crotalaria sessiliflora L. | Chhinchhine baja | x | ||||
| Leguminosae | Crotalaria sp. | Boksi ghanger | x | x | |||
| Leguminosae | Crotalaria sp. | Chhippi | x | ||||
| Leguminosae | Dalbergia latifolia Roxb. | Satisal | x | x | |||
| Leguminosae | Dalbergia sissoo Roxb ex DC. | Sisau | x | ||||
| Leguminosae | Derris sp. | Derri | x | ||||
| Leguminosae | Desmodium gangeticum (L.) DC. | Bhattamasejhar | x | x | |||
| Leguminosae | Desmodium oojeinense (Roxb.) Ohashi | Sandan | x | ||||
| Leguminosae | Desmodium sp. | Sal lahara | x | x | |||
| Leguminosae | Desmodium triflorum (L.) DC. | Chariamiliki mausi | x | x | x | x | |
| Leguminosae | Flemmgia macrophylla (Willd.) Merr. | Bhattamasi/Tinpate ghans | x | x | x | ||
| Leguminosae | Flemingia strobilifera (L.) Ait. | Bhatmas jhar | x | ||||
| Leguminosae | Indigofera pulchella Roxb. | Sagino | x | ||||
| Leguminosae | Lens culinaris Medik. | Musuro | x | ||||
| Leguminosae | Medicago lupulina L. | Jhuppe pyauli | x | ||||
| Leguminosae | Millettia extensa (Benth.) Baker | Gaujo | x | x | |||
| Leguminosae | Mimosa pudica L. | Lajabati | x | ||||
| Leguminosae | Phaseolus mungo L. | Ban masyang | x | x | |||
| Leguminosae | Phyllodium pulchellum (L.) Desv | Kanni jhangi | x | ||||
| Leguminosae | Smithia ciliata Royle | Lajaune jhar | x | ||||
| Leguminosae | Spatholobus parviflorus (Roxb.) Kuntze | Madane/Debre lahara | x | x | |||
| Leguminosae | Tadehagi triquetrum (L.) Ohasi | Jhumke lahara | x | ||||
| Leguminosae | Uraria lagapodioides (L) Desv. | x | |||||
| Leguminosae | Uraria lagopus DC. | Nilo tanki | x | ||||
| Leguminosae | Vicia angustifolia L. | Kutlikosa | x | ||||
| Leguminosae | Vicia tetrasperma Moench. | Aankura | x | x | |||
| Liliaceae | Asparagus racemosus Willd. | kurilo | x | ||||
| Liliaceae | Chlorophytum nepalense (Lindl.) Baker | Pyaje | x | ||||
| Liliaceae | Smilax ovalifolia Roxb. ex Don | Kukur daino | x | x | |||
| Lythraceae | Lagerstroemia parviflora Roxb. | Botdhairo | x | x | |||
| Lythraceae | Rotala indica (Willd.) Koehne | Belauti jhar | x | x | |||
| Lythraceae | Rotala rotundifolia (Buch -Ham. ex Roxb.) Koehne | Ambapate jhar | x | ||||
| Malvaceae | Sida rhombifolia L. | Balu | x | x | |||
| Malvaceae | Urena lobata L. | Balu/Chhipi | x | x | x | ||
| Marsileaceae | Marsilea crenata Presl | Charpate jhar | x | ||||
| Melastomataceae | Melastoma melabathricum L. | Angeri | x | ||||
| Meliaceae | Melia azedarach L. | Bakaino | x | x | |||
| Menispermaceae | Cissampelos pareira L. | Batulpate | x | x | x | ||
| Menispermaceae | Stephania elegans Hook. f. & Thoms. | Batulpate | x | x | x | ||
| Menispermaceae | Tinospora sinensis (Lour.) Merr. | Gudargano | x | ||||
| Myrsinaceae | Maesa chisia Buch.-Ham ex D. Don | Bilaune | x | x | |||
| Myrsinaceae | Myrsine semiserrata Wall. | Kalikath (Karauta) | x | x | |||
| Myrsinaceae | Myrsine sp. | Damai kath | x | x | x | ||
| Myrtaceae | Cleistocalyx operculatus (Roxb.) Merr. & Perry | Kyamun | x | x | x | ||
| Myrtaceae | Syzygium cumini (L.) Skeels | Jamun | x | x | x | ||
| Onagraceae | Ludwigia perennis L. | Lwang jhar | x | x | |||
| Ophioglossaceae | Ophioglossum petiolatum Hook. | Jibre sag | x | x | x | ||
| Oxalidaceae | Oxalis corniculata L. | Chariamili | x | x | x | x | |
| Piperaceae | Piper longum L. | Pipla | x | x | |||
| Poaceae | Axonopus compressus (Swartz) Beauvois | Makai banso/Thulo banso | x | ||||
| Poaceae | Brachiaria spp. | Banso | x | x | x | x | |
| Poaceae | Chrysopogon aciculatus (Retz.) Trin. | Kuro ghans | x | x | x | ||
| Poaceae | Cynodon dactylon (L.) Pers. | Dubo | x | x | x | x | x |
| Poaceae | Desmostachya bipinnata (L.) Stapf | Kush | x | x | x | x | |
| Poaceae | Dichanthiun annulatum (Forssk.) Stapf | Jhuse ankhle jhar | x | ||||
| Poaceae | Digitria ciliaris (Retz.) Koeler | Chitre banso | x | x | |||
| Poaceae | Digitaria spp. | Chitre banso | x | ||||
| Poaceae | Echinochloa colona (L.) Link | Sama ghans | x | x | |||
| Poaceae | Eleusine indica (L.) Gaertn. | Kode jhar | x | x | |||
| Poaceae | Eragrostris tenella (L.) Beauvois | Junge banso | x | x | x | x | |
| Poaceae | Eragrostris unioloides (Retz.) Nees ex Steudel | Chiure banso | x | x | x | ||
| Poaceae | Hemarthria compressa (L.f.) R. Br. | Ghode dubo | x | x | x | x | |
| Poaceae | Imperata cylindrica (L.) Beauvois | Siru | x | x | x | x | x |
| Poaceae | Ischaemum rugosum Salisb. | Madilo | x | ||||
| Poaceae | Leersia hexandra Swartz | Karaute ghans | x | ||||
| Poaceae | Oplismenus burmannii (Retz.) Beauvois | Ote banso | x | x | x | ||
| Poaceae | Paspalum distichum L. | Mane banso | x | ||||
| Poaceae | Paspalum scrobiculatum L. | Mane banso | x | x | x | ||
| Poaceae | Phragmites karka (Retz.) Trin. ex Steudel | Masino narkat | x | x | x | ||
| Poaceae | Pogonatherum crinitum (Thunb.) Kunth | Khari banso | x | ||||
| Poaceae | Polypogon monspeliensis (L.) Desf. | Puchhre jhar | x | ||||
| Poaceae | Saccharum benghalense Retz. | Baruwa | x | x | |||
| Poaceae | Saccharum spontaneum L. | Kans | x | x | x | x | x |
| Poaceae | Setaria pallide-fusca (Schumach.) Stapf & C. E. Hubbard | Jhusile banso | x | x | |||
| Poaceae | Sporobolus diander (Retz.) Beauvois | x | |||||
| Poaceae | Themeda arundinacea (Roxb.) Ridley | Khadahi | x | x | |||
| Polygalaceae | Polygala sp. | x | |||||
| Polygonaceae | Polygonum barbatum L. | Pire bikh | x | x | |||
| Polygonaceae | Polygonum plebeium R. Br. | Sukul jhar | x | x | |||
| Pontedenaceae | Monochoria hastata (L.) Solms | Jaluki | x | ||||
| Primulaceae | Anagallis arvensts L. | Krishnanil | x | ||||
| Primulaceae | Androsace umbellata(Lour.) Merr. | Chhate primula | x | x | |||
| Rhamnaceae | Zizphus nummularia (Burm. f.) Wight & Arn. | Deshi bayer | x | x | |||
| Rhamnaceae | Zizyphus mauritiana Lam. | Bayer | x | ||||
| Rosaceae | Fragaria indica Andr. | Bhuin kafal | x | ||||
| Rosaceae | Potentilla supina L. | Jangali bajradanti | x | ||||
| Rubiaceae | Anthocephalus chinensis (Lam.) A. Rich. | Karam | x | ||||
| Rubiaceae | Borreria articularis (L.f.) F. N. Williams | x | x | x | |||
| Rubiaceae | Hedyotis corymbosa (L.) Lam. | x | x | ||||
| Rubiaceae | Hedyotis diffusa Willd. | x | x | ||||
| Rubiaceae | Hedyotis gracilis Hook. f. | x | |||||
| Rubiaceae | Hedyotis lineata Roxb. | x | |||||
| Rubiaceae | Mitragyna parviflora (Roxb.) Korth. | Kaim | x | ||||
| Rubiaceae | Xeromphis spinosa (Thunb.) Keay | Mainkanda | x | x | x | x | |
| Rubiaceae | Xeromphis uliginosa (Retz.) Maheshwari | Pidar | x | ||||
| Rubiaceae | Wendlandia puberula DC. | kainyo | x | ||||
| Rutaceae | Murraya koenigii (L.) Spreng. | Asare | x | x | x | x | |
| Rutaceae | Skimmia arborescens T. Anderson ex Gamble | Asare | x | x | |||
| Sapindaceae | Schleichera oleosa (Lour.) Oken | kusum | x | x | |||
| Schizaeaceae | Lygodium flexuosum (L.) Sw. | parewapoti | x | x | |||
| Scrophulariaceae | Bacopa hamiltoniana (Benth.) Wettst. | x | |||||
| Scrophulariaceae | Lindernia anagallis (Burm. f.) Pennell | x | |||||
| Scrophulariaceae | Lindernia ciliata (Colsm.) Pennell | Karaute jhar | x | ||||
| Scrophulariaceae | Lindernia oppositifolta (L.) Mukerjee | x | |||||
| Scrophulariaceae | Lindernia sp. | x | |||||
| Scrophulariaceae | Mazus pumilus (Burm. f.) van Steenis | x | |||||
| Scrophulariaceae | Mecardonia procumbens (Mill.) Small | x | x | x | |||
| Scrophulariaceae | Scoparia dulcis L. | Chini jbar | x | x | |||
| Scrophulariaceae | Veronica anagallis-aquatica L. | Dhape jhar | x | ||||
| Solanaceae | Physalis divaricata D. Don | Patpate | x | x | |||
| Solanaceae | Solanum aculeatissimum Jacq. | Kantakari | x | ||||
| Solanaceae | Solanum surrattense Burm. f. | Kantakari | x | x | x | x | |
| Sterculiaceae | Helicteres isora L. | Simthi | x | x | |||
| Sterculiaceae | Melochia corchorifolia L. | Bankuro | x | ||||
| Sterculiaceae | Pterospermum acerifolium (L.) Willd. | Singane | x | ||||
| Tamaricaceae | Tamarix dioica Roxb. ex Roth | Jheuwa | x | ||||
| Theaceae | Schima wallichii (DC.) Korth | Chilaune | x | ||||
| Tiliaceae | Grewia helicterifolia Wall. ex G Don | Kharbuja | x | x | |||
| Tiliaceae | Grewia sapida Roxb. ex DC. | Pharsa | x | x | x | ||
| Tiliaceae | Grewia subinaequalis DC. | Dafer | x | x | |||
| Tiliaceae | Triumfetta rhomboides Jacq. | Dalle kuro | x | ||||
| Typhaceae | Typha angustifolia L. | Pater | x | x | x | ||
| Urticaceae | Gonostegia pentandra (Roxb.) Miq. | Sim chiple jhar | x | ||||
| Urticaceae | Pouzolzia zeylanica (L.) J. Bennett & R. Brown | Chiple jhar | x | ||||
| Verbenaceae | Callicarpa macrophylla Vahl | Dhaichamla | x | ||||
| Verbenaceae | Clerodendrum viscosum Vent | Bhanthi | x | x | x | x | |
| Verbenaceae | Gmelina arborea Roxb. | Khamari | x | ||||
| Verbenaceae | Lippia nodiflora (L.) Rich. | Bhuin okra | x | x | x | ||
| Verbenaceae | Premna integrifolia L. | Gindari | x | x | |||
| Vitaceae | Cissus repens Lam. | Charchare lahara | x | x | |||
| Zingiberaceae | Costus speciosus (Koenig) Smith | Bet lauri | x |
Table 2.
Summary of the composition of the vascular plant of western Chitwan
| Texa | Families | Genera | Species |
|---|---|---|---|
| Ferns and fern allies | 5 | 6 | 6 |
| Dicotyledons | 51 | 147 | 184 |
| Monocotyledons | 10 | 38 | 46 |
| Total | 66 | 191 | 236 |
Table 3.
Families with the largest number of genera and species in the vascular of western Chitwan
| Families | Genera | Species |
|---|---|---|
| Leguminosae | 23 | 38 |
| Poaceae | 23 | 27 |
| Asteraceae | 21 | 23 |
| Acanthaceae | 7 | 8 |
| Labiatae | 7 | 7 |
| Rubiaceae | 6 | 10 |
| Scrophulariaceae | 6 | 9 |
| Euphorbiaceae | 6 | 8 |
| Cyperaceae | 5 | 6 |
| Verbenaceae | 5 | 5 |
The genera with more than 2 species are listed in Table 4. Hedyotis, Grewia and Lindernia (4 spp. each) arc the largest genera, followed by Cassia, Crotalaria, Desmodium, Dioscorea, and Terminalia, each represented by 3 species.
Table 4.
Genera with the largest number of species in the vascular plant of Western Chitwan
| Genera | Species |
|---|---|
| Hedyotis (Rubiaceae) | 4 |
| Lindernia (Scrophulariaceae) | 4 |
| Cassia (Leguminosae) | 3 |
| Crotalaria (Leguminosae) | 3 |
| Desmodium (Leguminosae) | 3 |
| Dioscorea (Dioscoreaceae) | 3 |
| Grewia (Tiliaceae) | 3 |
| Terminalia (Combretaceae) | 3 |
| Acacia (Leguminosae) | 2 |
| Ageratum (Asteraceae) | 2 |
| Bauhinia (Leguminosae) | 2 |
| Commelina (Commelinaceae) | 2 |
| Cyperus (Cyperaceae) | 2 |
| Dalbergia (Leguminosae) | 2 |
| Digitaria(Poaceae) | 2 |
| Eragrostis (Poaceae) | 2 |
| Euphorbia (Euphorbiaceae) | 2 |
| Flemingia (Ieguminosae) | 2 |
| Justicia (Acanthaceae) | 2 |
| Leea (Leeaceae) | 2 |
| Litsea (Lauraceae) | 2 |
| Myrsine (Myrsinaceae) | 2 |
| Paspalum (Poaceae) | 2 |
| Phyllanthus (Euphorbiaceae) | 2 |
| Polygonum (Polygonaceae) | 2 |
| Rotala (Lythraceae) | 2 |
| Solanum (Solanaceae) | 2 |
| Uraria (Leguminosae) | 2 |
| Vicia (Leguminosae) | 2 |
| Xeromphis (Rubiacea) | 2 |
| Zizyphus (Rhamnaceae) | 2 |
The frequency distribution of species per genus, genera per family and species per family is given in Figure 1. One hundred and sixty (83.77%) genera contain 1 species each, followed by 23 genera with 2 species each. Similarly, 29 families have 1 species each, 15 with 2 species each and 11 with 3 species each. Eleven (16.66%) families include species ranged from 4–38. representing 61.02% of the flora. Two families contain the highest number of genera (23 spp each). The majority of the families (35 spp., 53%) each represents a single species followed by 16 families with 2 species each.
Figure 1.
Common and unique species
An analysis of the composition of flora in respect to the study plots shows that Tikauli forest and the National Park forest share the highest number (69 spp.) of common species, whereas grassland (BL) and forest C have the least common species (Table 5). The above data indicate that the forests of the National Park and Tikauli are floristically more similar to each than other blocks. Block A contributes the highest unique species (99 species) and the least unique species by the GL (only 15 species). The common land plants common to the Forest A, Forest B, Forest C, and GL amount to 49, 36, 31, and 21, respectively. The occurrence of a higher number of common land plants in the Tikauli forest indicates a higher anthropogenic impact on the environment of this forest. The species common in these two blocks (A and CL) include Cassia tora, Echinochloa colona, Eleusine indica, Euphorbia hirta, Evolvulus nummularius Hedyotis corymbosa, Hedyois diffusa, Hyptis suaveolens, Ludwigia perennis, Polygonum plebeium, Rotala indica, Scoparia dublcis. Setaria pallid-fusca, Vicia terasperma and Xanthium strumarium. The species mentioned above were also reported from highly disturbed part of Tikauli forest (located in the eastern side of the East-West Highway), rice fields, summer and winter crop fields (Dangol et al., 1995; Dangol et al., 1986 and 1988; Dangol, 1990a, 1990b, and 1991; Dangol and Baral, 1986; Gupta et al., 1977).
Table 5.
The number of common species in research blocks in Western Chitwan, Jan-April, 1996
| Sites | A | B | C | GL | CL |
|---|---|---|---|---|---|
| A | 0 | 69(50) | 34(85) | 20(99) | 47(70) |
| B | 69(44) | 0 | 27(86) | 27(86) | 36(77) |
| C | 34(25) | 27(32) | 0 | 13(46) | 31(28) |
| GL | 20(15) | 27(8) | 13(22) | 0 | 21(14) |
| CL | 49(70) | 36(83) | 31(88) | 21(98) | 0 |
The figures in parenthesis indicate unique plant species In respective research blocks A (Tikauli forest), B (National Park), C (Forests along the Narayani river), GL (Grassland of National Park), and CL (common land) Example, in 69 (50), 50 species not recorded in Block B.
Major taxa in different blocks
The top families in terms of the occurrence of the number of species are depicted in Table 6. In Blocks A and B, the top most rank of the families is occupied by the Leguminosae followed by Poaceae in Block A and Asteraceae in Block B. The Poaceae is the largest family in Block C and Block CL, whereas the Asteraceae is the top family in Block GL. These largest families account for 52.10%, 49.55%, 55.93%, 57.14%, and 50.42% of the total flora in Block A, B, C, GL and CL respectively. These data indicates that the majority of the species (i.e. 50 or more than 50% of the flora) is contributed by top five families.
Table 6.
The largest families of the vascular plans in Western Chitwan, Nepal.
| Top Families | Blocks | ||||
|---|---|---|---|---|---|
|
| |||||
| A | B | C | GL | CL | |
|
| |||||
| Acanthaceae | 3 | 4 | 3 | 3 | 4 |
| Asteraceae | 11 | 10 | 8 | 9 | 14 |
| Cyperaceae | - | - | - | - | 6 |
| Euphorbiaceae | 3 | 6 | - | - | 4 |
| Labiatae | - | - | 3 | - | - |
| Leguminosae | 20 | 17 | 2 | - | - |
| Menispermaceae | - | - | 3 | - | - |
| Myrsinaceae | 3 | - | - | - | - |
| Poaceae | 16 | 10 | 9 | 6 | 23 |
| Rubiaceae | 6 | 5 | - | - | 4 |
| Scrophulariaceae | - | - | - | 2 | 7 |
| Solanaceae | - | - | 2 | - | - |
| Verbenaceae | - | 4 | 2 | - | - |
Trees of the forests
Shorea robusta and Terminalia alata are the major trees found in the Tikauli forest. It is interesting to note that the S. robusta trees are higher in the exterior part compared with middle and interior parts of the Tikauli forest. This is possibly because they share their habitat with other tree species like Cleistocalyx operculatus, T alata, and Lahare pipal. Also, it may be due to the ease of felling trees in this area compared to the exterior and middle parts where forest guards are more likely to be patroling. In the exterior part of the National Park forest, Trewia nudiflora and Bombax ceiba are the major components of the forest forming the Trewia-Bombax tree community. S. robusta and C. operculatus are the two major trees in the interior plots and are accompanied by Dillenia pentagyna, and Lagerstroemia parviflora. The species such as T. nudiflora, B. ceiba, Litsea monopetala, and Mallotus philippensis showed a decreasing pattern of plant population from exterior to interior sites in the National Park. In the forests along the Narayani river, Dalbergia sissoo is the main tree in the study plots, except in Kalaban, which is a natural forest on an island in the Narayani river. Other trees recorded in Kalaban only are B. ceiba, T. nudiflora, and Ehretia laevis.
Shrubs and saplings of the forests
Among the six shrubs, the most common species are Clerodendrum viscosum, Pogostemon benghalensis, Colebrookea oppositifolia, Eupatorium odoratum, Grewia sapida, Helicteres isora and Callicarpa macrophylla. are found to be higher in the exterior plots of the Block A. In the National Park forest (Block B), G. sapida and H. isora prefer the interior habitats whereas C. macrophylla, C. viscosum, and P. benghalensis are abundant in the exterior plots of the forest. However the major shrubs in the forest along the Narayani river are comprised of P. benghalensis, C. oppositifolia, C. viscosurn, Melastoma malabathricum, Murraya koenigii, and Coffea benghalensis. is one of the successful plants in the sissoo plantation areas. It has also been reported as a weed found in pineapple orchards in Rampur (Dangol and Baral, 1986). The saplings of S. robusta were recorded from Block A and Block B, but found less abundantly in the interior plots of Block A. The saplings of S. robusta tree were found five times more in the interior parts compared to the exterior part of Block B. The saplings of Swida oblonga, C. operculatus and T. alata were In an Increasing order from the exterior to the middle to interior Block A. Some saplings of trees such as D. sissoo, Myrsine sp. (Damaikath), Premna integrifolia, etc. were also observed in Block C.
Herbaceous flora and seedlings of the forests
S. robusta seedlings occur as one of the dominant species in the Block A and Block B. The chance of S. robusta seedlings growing into a tee is less in Block A because the habitats are frequently disturbed by human activities such as grazing animals, collecting fuel-wood, and forest firing. C. viscosum seedlings are also recorded in Block A. Tall grasses are the major species in the ground flora of the forest and grasslands. The three species dominating the grasslands are Imperata cylindrica, Saccharum spontaneum, Saccharurn benghalense and Themeda arundinacea. Blumeopsis flava is one of the dominant herbs in Block A, whereas Rungia parviflora, Oxalis corniculata, Ageraturn houstonianum), Commelina benghalensis and Blumea spp (Mulapate) are the major species in Block C.
Herbaceous flora of the common lands
In the study area, grasses are the major species that constitute the plant communities in the common lands. Among grasses, I. cylindrica is a major species in plantation areas, common grazing areas, Pokhari/Ghole areas and canal ways. It prefers mostly plantation areas with less disturbance but poor soils. It has also been reported as one of the dominant weeds in pineapple orchards in Chitwan. (Dangol and Baral, 1986) S. spontaneum is the most important species of the floodplain areas. Other common grass species in the common lands include Cynodon dactylon and Chrysopogon aciculatus, the latter can tolerate very adverse situations like frequent trampling or cutting because it is prostrate in its vegetative stage. Also, its fruits are dispersed very easily by agents such as man, sheep, etc. The most frequently recorded dicot species are Desmodium triflorum, R. parviflora, O. corniculata and Evolvulus numrnularius. They are prostrate in habit, protecting them from grazing and cutting. The other dicot species represented less frequently include Medicago lupulina, Launaea aspleniifolia, Lippia nodiflora, Rotala indica, Hydrocotyle sibthorpioldes, Centella asiatica and A. houstonianum. Among them, A. houstonianum is claimed by farmers to be a poisonous to their livestock. In the habitats, which are frequently disturbed by nature i.e., floods or human activities like firing, grazing, felling, or construction, perennial species tend to replace the annuals. For example, in the floodplain areas, we observed only a few annuals, but many strong perennial plants like S. spontaneum (which sends long runners) and Equiseturn debile (with deep rhizomes and roots to draw water and minerals from deep zone of soil).
Acknowledgments
This research was supported by a grant from the USA’s National Institute of Child Health and Human Development (Grant No. ROI-HD 33551). We extend our sincere thanks to Dr William G. Axinn (Principal Investigator), Dr, Kerry Richter, Dr. Stephen Matthews, Dr. Jennifer Barber, Dr. Kishor Gajurel, Mr. Netra Chhetri, Harimaya Poudel and Mr. Rajendra Darai for their contribution to the research. Dr. S. L. Ranamukharaachchi, Visiting Faculty, Agricultural Systems, AIT, Thailand is also thanked for his valuable comments on the earlier version of the manuscript and Dr. Lisa Pearce is gratefully thanked for grammatical correction. We are also thankful to the reviewer for critical comments on the manuscript.
Contributor Information
D. R. Dangol, Email: iaas@perl.wlink.com.np.
G. P. Shivakoti, Email: Ganesh@ait.ac.th.
References
- Chhetry N. Design of the forest flora research plots for the project on “Reciprocal relationship between population and environment”. Population and Ecology Research Laboratory, Institute of Agriculture and Animal Science; Rampur, Chitwan, Nepal: 1996. [Google Scholar]
- Dangol DR. Ecological study of weed flora associated with sorghum at Rampur. Nepal Geobios new Report. 1990a;9(1):81– 83. [Google Scholar]
- Dangol DR. Lentil weeds in Rampur, Chitwan Valley, Nepal. Lens News-letter. 1990b;17(1):11–13. [Google Scholar]
- Dangol DR. Ricefield weeds in Chitwan Valley, Nepal. IRRN. 1991;16(3):27–28. [Google Scholar]
- Dangoi DR, Baral DR. Survey of weed flora in pineapple (Ananus comosus Mill.) at Rampur, Chitwan Valley, Nepal. Nepalese J Agric. 1986;17:109–177. [Google Scholar]
- Dangol DR, Pandey MP, Pandey P. Weeds of winter vegetable crops at Rampur, Chitwan, Nepal. Indian J Weed Sci. 1988;20(1):40–45. [Google Scholar]
- Dangol DR, Gurung SB. Preliminary survey of major field crops weeds and farmers’ weed management practices in Chitwan, Nepal. A report submitted to Royal Nepal Academy of Science and Technology (RONAST); Kathmandu, Nepal: 1988. [Google Scholar]
- Dangol DR, Gurung SB, Bhattarai I. Lowland rice weeds at the agronomy farm of IAAS, Rampur, Chitwan, Nepal. J Inst Agric Anim Sci. 1986;7:1–11. [Google Scholar]
- Dangol DR, Gurung SB, Bhandari A. Research Report. NFMP/IUCN and NAHSON; Chitwan Nepal: 1995. Studies on plant communities of natural and man-engineered ecosystems in Chitwan alley; pp. 116–162. [Google Scholar]
- Gupta OP, Bajracharya SB, Shivakoti GP. A study of weed Problems at Rampur, Chitwan. Nepal J Inst Agric Anim Sci. 1977;1:1– 86. [Google Scholar]
- Joshi SR, Jha PK. Biomass production in grasslands of the Royal Chitwan National Park. Nepal Ecoprint. 1995;2(1):40–45. [Google Scholar]
- Lehmkuhl JF. A classification of subtropical riverine grassland and forest in Chitwan National Park. Nepal Vegetatio. 1994;111:29–43. [Google Scholar]
- Richter K, Chhetri N. Issues and strategies for understanding population and ecology interlinkages in western Chitwan. In: Shivakoti G, Varughese G, Ostrom E, Shukla A, Thapa G, editors. People and participation in sustainable development: understanding the dynamics of natural resource systems; Proceedings of an International Conference held at the Institute of Agriculture and Animal Science; Rampur, Chitwan, Nepal. 17–21 March 1996; Bloomington, Indiana and Rampur, Chitwan. 1997. pp. 114–125. [Google Scholar]