Results and Discussion

Vegetation: Vegetation studies in the Himalyan region dates back to the early 19th century by Troup (1921), Champion (1921), Osmaston (1923), Schweinfurth (1957), Puri (1960) and  Champion and Seth (1968). Quantitative assessments of vegetation in western and central Himlaya were carried out by Saxena (1979), Pandey (1979), Negi (1979), Ralhan et al. (1982), Saxena and Singh (1982a,b), Tewari (1982), Tewari and Singh (1985), Upreti et al. (1985), Singh and Singh (1984 a, b and c), Singh, et al. (1985). Singh and Singh (1987a), Rikhari et al. (1989), Tewari et al. (1989), Reddy (1989), Lodhiyal (1990), Rawal (1991), Singh and Rawat (1999) and Rana et al., (2010).  Plate 2 depicts the floral diversity across watersheds (high altitude, mid and low altitudes). Ecological studies in the Kumaun region in the eastern part of Western Himalaya has been done by Adhikari (1992; 1995). In this backdrop, this study was undertaken to assess the floral diversity in the study areas which are ecologically distinct and hitherto least studied region. Quantitative assessment of woody species in the three micro watersheds is detailed in Table 3. Transects are named with first two letters of the microwatershed (abbreviations Ma: Mandhala, Mo-Moolbari and Me: Me Gad). Transect wise analysis in each of the micro watershed is discussed below.

Moolbari: Total number of species (15 species) and number of individuals (188) was high in Mo-15, which is Rhododendron arboreum and Quercus mixed forest. Mo-4 was species deficient (5 species) as these forests were dominated by Quercus glauca. Mo-1 had the highest basal area contributed mainly by Quercus glauca followed by Quercus leuchotrichophora. Mo-15 showed highest Pielou species richness value of 2.67, while it was lowest in Mo-4 with 0.92. Shannon diversity was highest in Mo-15 (1.72). This is due to the presence of several evergreen species such as Persea, Euonymous, Myrica sp etc., in the valleys. The higher slopes generally has Quercus species, mixed with Rhododendron. With dominance value of 0.73, Mo-11 showed the highest species dominance and had low Simpson value (0.34). This higher dominance is mainly due to Quercus leucotrichophora, which has 92 individuals and only 16 individuals of all other species.

The higher dominance of Quercus leucotricophora is reflected in the IVI value of 109.40, which is the highest for Moolbari water shed (Table 4). This is followed by Quercus glauca with 62.18. Pinus roxburghii is found extensively covering some of the slopes and has an IVI of 16.49. Mixed with these dominant species are species of Acer oblongum with IVI of 13.39, Myrica esculenta with 13.01. Rhododendron arboreum with IVI of 9.08 mostly occurred in Mo-15, which is relatively wetter compared to other transects. Other species such as Cedrus deodara with IVI of 8.01 occured in valleys and Pyrus pashia with 6.98 is scattered throughout the watershed.

Mandhala: 11 transects were laid in Mandhala water shed area. Total individuals recorded in these transects were 447 with the highest number of individuals (84) recorded in Ma-6. Acacia catechu with higher number of individuals constitutes a dominant species. This species was planted earlier by forest department under afforestation programme. Lower number of individuals was recorded in Ma-5 and Ma-10 with severe degradation. Species richness was more in Ma-2 with 21 species and lowest in Ma-9 with 3 species. Basal area was highest in Ma-2 and lowest in Ma-7. Table 3 details transect-wise data for all three micro watersheds. The higher species diversity and basal area in Ma-2 can be attributed to the fenced protection provided by the farmers residing in the region that has ensured the survival of saplings. Hills adjoining this transect without fencing were totally barren, filled with impenetrable thickets of Lantana shrubs. The highest diversity was in Ma-2, which also has highest Shannon value of 2.6, Simpson diversity of 0.9 and dominance  value of 0.09. The least diversity was in Ma-8 dominated by Acacia catechu with Shannon value of 0.63 and dominance of 0.73. Acacia catechu had the highest IVI of 61.19, followed by Flacourtia indica (28.51), Mangifera indica, (26.04), Odina (19.07), and Anogeissus latifolia (15.35) as listed in Table 4. Dominating deciduous trees in the region are Acacia catechu, Flacourtia indica, Anogeissus latifolia and Odina wodiyer.

Me Gad:  This micro watershed is relatively species poor. However, basal area was highest in Me-7 with 4.05 contributed by Abies pindrow and Pinus wallichiana. The lowest basal area was in Me-5 with 0.27, predominantly sub-alpine grasslands with scattered trees. The overall species diversity in MeGad was very low with Shannon diversity of 0.9 in Me-1, with only 4 species in entire transect. Me-5 is a alpine grassland and cultivated in some areas had only one species with lowest diversity.

Abies pindrow with 94.61 and Pinus wallichiana with 83.30 show a very high IVI value (Table 4). These are followed by Picea smithiana (58.58) and Salix denticulate (27.34).

Table 3. Micro watershed wise Vegetation analysis

Discussion

Mandhala, Moolbari, and Me Gad micro watersheds had a total of 2276 individuals from 75 woody species from 34 belt transects, relatively higher than earlier reports (Singh and Rawat 1999; Rana et al., 2010). A total of 38 families were recorded, of which Fabaceae had the highest number of species (7), followed by Rosaceae, Pinaceae and Moraceae (5 each). The highest number of individuals per species was Quercus leucotriphora with 811 individuals followed by  Q. glauca (394), Acacia catechu (157), Myrica esculenta (73), Pinus roxbhurghii (72),  Abies pindrow (70) and Flacourtia indica (68).

Species richness was highest in Mandhala (45 species) followed by Moolbari (39) and MeGad (9). Although Mandala had the highest species diversity, it had lowest dominance. Most of the species are thorny shrubs and rarely attain tree forms due to severe anthropogenic disturbances in this watershed, hence very low basal area is observed compared to number of other species. In Moolbari, which had the highest basal area (39.94) was mainly contributed by Quercus leucotricophora and Q. glauca. In Mandhala, the negligible basal area found was due to absence of large trees as in Moolbari or MeGad, due to the earlier deforestation and extensive encroachment of forestland by obnoxious weed Lantana camara. This shrub has totally covered the lower slopes in Mandhala making it an unsuitable habitat for wildlife as well as domesticated animals. Also regeneration of forest plant species has totally ceased due to the permanent cover created by this bush.

Overall Quercus species dominated in the Moolbari watershed area, while deciduous species such as Acacia catechu, Flacourtia indica dominated in Mandala watershed. MeGad, a high altitude area was dominated by Abies pindrow, Picea smithiana, and Pinus wallichiana, which is reflected in the IVI values (Table 4).

Table 4: IVI  for woody species in Mandhala, Moolberi and Me Gad watersheds

Faunal diversity

Butterfly: The present study enumerated 115 butterfly species of oriental and palaearctic origin representing nine families. Nympahlidae is the dominant family (32 sp.) followed by Pieridae (19 sp.), Lycaenidae (16 sp.), Satyridae and Papilionidae (12 sp. each), Hesperridae (10 sp.), Danaidae (8 sp.), Erycidae (4 sp.) and Acraeidae (2 sp.).  Table 5 details the butterflies in the three micro watersheds identified based on standard keys (Wynter-Blyth, 1940-1946, 1957; Thomas and Malorie, 1985; Mani, 1986; Leps and Spitzer,  1990; New 1991; Scoble, 1992; Wood and Samways, 1992; Kim, 1993; Pollard and Yates, 1993; Samways, 1994; New et al., 1995; Molina and Palma, 1996; Parmesan, 1996;  Swengel, 1996; Blair and Launer, 1997; Spitzer et al., 1997;  Stork et al., 2003)

Table 5:  Butterfly species across three micro watersheds of Himachal Pradesh

Amphibians: In the present study, 14 species were observed belonging to 5 families and diversity is listed in Table 6. Of the 5 families, Dicroglossidae represents 7 species, followed by Bufonidae (4) and Microhylidae, Ranidae and Rhacophoridae (1 species each). Six species are first reported from this study. 

Table 7 details the relative abundance in three watersheds comparable to the earlier reports (Mehta, 2005a, b; Beebee and Griffiths, 2005). Figure 2 depicts few amphibians recorded during this study. Mandhala watershed located in the Shivaliks is bestowed with numerous ponds, pools, streams and rivers. Most of the streams and river drain off the rainwater as soon as it rains, without any water retaining in the streams. Only ponds and pools retain water for considerable time and could be one of the reasons that majority of the amphibians observed from the regions are pool breeders dominated by Euphlyctis cyanophlyctis, Microhyla ornata, Fejervarya sp. and Polypedates maculates. Sphaerotheca breviceps, a burrowing frog was observed in the dry beds of river. Euphlyctis cyanophlyctis was found in both streams as well as in pools. Moolbari watershed belongs to the mid Himalayan ranges and many streams originate forming a network. As it has higher elevation and more streams, frogs that breed in streams predominate the region. Paa minica was observed in almost all streams with water, and having canopy cover. In agriculture fields and forested areas, Bufo himalayanus and Duttaphrynus melanostictus were recorded. Altitude and extreme temperature in MeGad watershed appears inhospitable to amphibians as it is evident from their absence while recordings during this fieldwork.

Table 6: Amphibian diversity in the three micro watersheds of Himachal Pradesh

# Nomenclature based on Frost et al (2006)
* Observation by Zoological Survey of India.

Table 7:  Relative abundance (individuals/hour of search) of amphibians recorded during the study.

Avifauna diversity and richness: Sampling was done following the standard protocol (Ali, 1989; Grimmet, et al., 1998; Laiolo, 2003) in different habitat types:  forests, glacier, agriculture and forests, riverine, and agriculture. Habitatwise speces richness is given in Table 8 for Moolbari, MeGad and Mandhala watersheds respectively.  The distribution of bird species in the three watersheds is summarised in Table 9.  Eight species of birds common to all three watersheds, in an altitude of 400 to 4000 m. 31 species common to Mandhala and Moolbari watershed, in the altitudanal range of 400 to 2000 m. Nine species common to Moolbari and Me Gad Watersheds. The habitat wise study revealed that bird species richness is more in forest patches of Mandhala and MeGad Watersheds, whereas, forest and agriculture mixed habitats in Moolbari had more species. In total, 136 bird species were recorded in three watersheds. Mandhala watershed records highest number of species (105) followed by Moolbari (57) and Megad (35).

Figure 2. Amphibians from Moolbari and Mandhala watersheds. A. Paa minica B. Bufo himalayanus C. Amolops chakrataensis D. Bufo sp. E. Polypedates maculates F. Sphaerotheca breviceps G. Euphlyctis cyanophlyctis H. Microhyla ornata

Plate 1: Mandhala, Moolbari and MeGad Watersheds, Himachalpradesh

Plate 2: Vegetation profile in the watersheds

Table 8: Habitat wise bird species richness in Moolbari, Mandhala and Me Gad watersheds

Table 9:  Comparative distribution of bird species in the three watershed