Joint Forest Management (JFM)/ Peoples’ Participatory Plantation

This plan has been constituted under the National Afforestation Program, 1990 (Conservation with communities in the biodiversity hotspots of India, WWF India, 2002) with a view to execute and materialise the policy of the government by way of active participation and involvement of local people for regeneration, maintenance and protection of forests owned by the state but appropriated by the local communities. The working area covers both peripheral degraded as well as some of the encroached areas of the Reserve.

The economic prosperity of the surrounding population is intimately associated with the proper management of this Reserve. There are almost 8 different ethnic tribes living in the fringe villages and although their agricultural customs vary to a certain extent, all of them cultivate paddy in the low-lying land adjoining the reserve. They raise only one crop in a year from June-July to December. The cattle maintained by these villagers are entirely dependant on the reserve for their grazing till paddy is harvested. The basic needs of the villagers like firewood, thatch, bamboo, and cane are met from this reserve. So to stop destruction of the forests and decrease encroachment, this plan intends to create a buffer with peoples’ participation. The local people are therefore involved in converting the encroached and degraded areas into productive land so as to meet their basic needs on sustained basis. Their involvement in regeneration and other silvicultural operations is being implemented and the government in return provides a subsidiary income to the local villagers in the form of wages. However most of these locals are poverty stricken and do not have the patience to wait for a long time to get their due share of earnings from raising and protecting the plantations for which they had worked hard. Therefore such species have been chosen so that the villagers minimum rights can be met right from the 5th year of plantation in a sustained manner. So by generating a sustainable interface between the

Forest department and the local community it can be a possible way through which the interests of the people and long-term sustainability are harmonised in a mutually supporting manner.

As a part of the biomonitoring program to study the effects of forest management, population survey of larger herbivores like elephants and gibbons have been carried out on permanent line transects to study different habitat utilization patterns and the current elephant population is 502 (Forest records, 2005). Although the reserve has been listed as a disturbed area, it has still good conservation potential especially with respect to a good plant diversity including medicinal plants, mammals and birds. There is no previous documentation on the butterfly fauna in this area, but a comprehensive inventory showing a checklist of the available species of butterflies in the reserve also highlights the potential of this protected area as a good “butterfly reserve”. However the most significant feature about the management strategy for this reserve is its potential for being managed as a good natural

“elephant corridor”. The Deepor beel on the northern side of the reserve is the perennial water source for the elephants. Large herds also come down from the adjoining hills of the Meghalaya forests for drinking, bathing and eating the aquatic plants in the lake. Protection of the habitat will help to reduce the man- elephant conflict and at the same time envisage elephant conservation through local community involvement (Daniel et al., 1995).

Elephants influence forests at two main levels – as opportunistic frugivores, by directly effecting the dispersal and regeneration of certain plant species; and by trampling, debarking and disturbing the forest (Hoft & Hoft, 1995; Johnstone, 1967; Laws et al., 1970, 1975;

Sheil 1996; Struhsaker et al., 1996; Wing & Buss 1970). In light to moderately logged forests, the elephants were found to use the forest gaps more than the closed canopy areas for foraging and the selective browsing of young trees by elephants affected the rates of forest regeneration, growth form and species composition (Struhsaker et al., 1996).

Therefore the elephants can be taken as a keystone species for the effective conservation and management of this reserve. The WWF-India under its current elephant conservation project in Assam has also targeted Rani-Garbhanga Reserve for protection as an ‘elephant reserve’. Several environmental organisations have also sent proposals to the state government for upgrading Rani-Garbhanga Landscape into an “urban wildlife sanctuary” as the proximity of this protected area to the capital city can also contribute towards the development of ecotourism. The division of International Conservation (US Fish and Wildlife Service, 2006) has also proposed for the strengthening of the conservation of Hoolock gibbon in Rani-Garbhanga Landscape, gather baseline information on the

biodiversity of this sanctuary along with constructing one anti-poaching camp and designing a strategic conservation and management plan for the landscape.

CHAPTER 4 : METHODS CHAPTER 5 : RESULTS

CHAPTER 4 : METHODS

4.1 Study Sites

A 50 ha study area covering five different sites or locations were selected for butterfly sampling and conducting field observations. All the five study sites were selected using satellite imagery. Sites S1, S2 and S3 were located in Garbhanga range, sites S4 and site S5 were within Rani range. The levels of disturbance in the five study sites were not quantified but were evaluated on a visual scale. The sites were partially to heavily disturbed areas with respect to human settlements, grazing, shifting cultivation, teak monoculture, earth-cutting, small wood collection by local villagers, illegal selective logging by timber smugglers and presence of stone-quarry as described in Table 4.1. However movement of people and small logging were observed to be the main disturbance parameters.

Table 4.1: Study sites in Rani-Garbhanga Reserve forest

Study site

S3 (Garbhanga) 26° 01’39.18”-91°39’03.91”

5 Secondary euphorbiaceous scrub with grasses growing upto 10-15 cm on the rocky slopes and hills in the areas near to the abandoned

Notes: The area measurement for each study site was calculated using the GPS data. The changing patterns of land-use and forest cover associated with disturbances can be observed in the GIS maps on Rani-Garbhanga Reserve Forest (see Figs. 4.1 & 4.2, and Table 4.2).

4.2 Satellite Image Preparation, Interpretation and Area Estimation

Satellite remote sensing has played a key role in generating information about forest cover, vegetation type and land use changes (Houghton & Woodwell, 1981; Botkin et al., 1984). Satellite data have also been used to quantify tropical deforestation and habitat fragmentation in the spatial context (Skole & Tucker, 1993). Changes in shape and size of forest fragments can be assessed using satellite data and in a GIS environment. Remote sensing has also been applied in the present study. Survey of India topomaps on 1:50,000 scale was first used for preparation of the base maps.

Satellite images from IRS – 1C and 1D Linear Imaging Self-Scanner System (LISS – II and III) sensor with ground resolution of 36.25m x 36.25m were used for classification of

vegetation cover. The image scale for the satellite images was 1:30,000 and geo-referencing of the master scene has been carried out on this scale using ancillary data and GPS locations.

Landcover classification was done within the study area using remotely sensed satellite imagery (IRS IC LISS III).

Visual interpretation technique was employed to deliniate different land-cover classes from the digital satellite data (False Colour Composite) under GIS environment (ARC GIS 9.1).

The land-cover classes were identified as per a standard classification system generated by the Department of Space, Government of India. The areas under different land-cover classes were calculated from the map by the facilities with the GIS (which are presented in the Table 4.1).

Satellite images were also visually interpreted to show the details of the drainage pattern in the study area and two separate images have been prepared with one image having the GPS locations superimposed on the actual image (see Fig. 4.2).

The GPS data collected from the field in March 2003 were incorporated as “Point Information” (latitude and longitude) in a separate layer, which were superimposed onto the satellite imageries as well as land-cover maps. Based on actual field data collection on the swallowtail butterflies and vegetation, 24 points covering the 5 study sites within the study area are shown in the imagery maps. Comparative GPS data from 2 years – 1998 and 2002 was acquired to assess the change in forest cover and land-use patterns in line with the changing trends of disturbance (see Table 4.2).

Altogether three types of input maps – topomap showing the protected forest boundary and geographic location of the study area, drainage pattern map and vegetation/land-use cover map were prepared for further studies. The analysed version of the vegetation and land-use pattern of the protected reserve is presented in Table 4.2.

Table 4.2: Land-use analysis of the study area in hectares (1998 and 2002)

Area in hectares Landscape type

1998 2002

Moist Deciduous forest 21561.39 21230.4 (includes the river area of 189.88)

Agriculture (Kharif/Summer crops) 210.14 12.3 Cropland (inside forest) 30.00 39.12

Marsh/Swampy area 3.6 9.21

Mixed built-up land (Residential, Planted vegetation

and commercial area) 54.5 72.5

Household plantation 26.56 202.3

Open forest 1.36 33.46

Scrub forest 53.23 18.35

Forest plantation 13.04

*Land with scrub 41.82

Shifting cultivation 480.5 796.27 (Current)

Shifting (Abandoned) 691.71

River 189.88

Total 22611.16 23160.48

Notes: * Land outside the notified area as per the land–use classification norms. The interpretation for 1998 has been carried out visually from IRS LISS II data of 1998.

Data source for 2002 are from IRS 1D LISS III FEBRUARY (2002). The above interpretation and preparation of the GIS images were done in the “Assam Remote Sensing Application Centre, Guwahati, Assam, India.

Figure 4.1: GIS image showing the land-use pattern in Rani-Garbhanga Reserve forest in 1998.. GPS points superimposed on the image show the data collection locations pertaining to butterfly identification, vegetation survey and general field observations during initial phase of research work in 2001-2002.

Figure 4.2: GIS image showing the change in the land-use pattern associated with human disturbances within the forest reserve over a period of four years (1998-2002). Study sites S1, S2, S3, S4 and S5 selected for initial phase of research study associated with vegetation and swallowtail butterfly (Papilionidae) identification and final phase of study for vegetation and butterfly sampling are shown in the map. GPS points superimposed on the

S1

S2

S3 S4

S5

image indicate the sampling points pertaining to the geographical position (latitude and longitude), altitude and general field observations.

The GIS images of the study area over a period of five years from 1998 to 2002 shows a good forest cover along with the different land-use patterns and also the changing trends of disturbance in the protected area primarily associated with deforestation due to human activities. The satellite data on 1:50,000 scale are found to some extent adequate for classification (with bare eyes) of degraded/scrub (<10% crown), open (10-40% crown) and dense/closed (>40% crown). The satellite images indicated an increasing trend of disturbance and deforestation within the boundaries of the reserve primarily caused by illegal encroachment, shifting cultivation and other anthropogenic interferences in the form of the fringe forest villages and disturbances caused by one pocket of habitation (Garo tribal village) inside the reserve (see Figs. 4.1 & 4.2))

4.3 Sampling

4.3.1 Sampling period

The study was conducted for a period of two years from 2003 to 2004 covering 2 different seasons – Dry season (Post monsoon) from January to March and Wet season (Monsoon) from August to October. All surveys and samplings were limited to sunny days, under calm to light wind conditions when mean atmospheric temperature was about 32°C, average humidity was about 80%. The following hours of the day were selected for field survey and collection of butterflies: Early morning hours – 7.00 h to 13.00 h and late afternoon hours – 14.00 h to 17.00 h.

4.3.2 Sampling design

In the study area, based on the observed levels of disturbance and the satellite images, we considered such factors like the degree of canopy closure, availability of sunlight on the forest floor and presence of both natural and man-made gaps, and accordingly each of the five study sites were demarcated into two zones for the sampling of butterflies - a) Scattered forest (SCF) and b) Closed forest (CF)

Line transect sampling method (Pollard 1977, 1984; Thomas 1983; Pollard & Yates 1993) was followed in the five study sites for monitoring the swallowtail butterfly community and predicting the species diversity and distribution pattern of the Papilionids within the forest reserve. This method is now extensively used to survey and monitor butterfly populations and communities (Shreeve & Mason, 1980; Erhardt, 1985; Warren et

al., 1986; Yamamoto, 1988; Ishii, 1993; Pollard & Yates, 1993) and has been applied in Vietnam in previous work (Spitzer et al., 1987; 1993; Vu & Dang, 2002). As the protected reserve is divided into two ranges for management purposes, therefore butterfly sampling was done separately for the study sites of Rani and Garbhanga ranges (see Fig. 4.3). The records were based on visual sightings during the transect walk, active captures using nets, counts from ‘mud-puddling’ sites along the stream and areas of human habitation located along the transects. The sampling period covered the flying periods of most species. Some short visits were also made in other parts of the years for deriving complementary information.

Figure 4.3: Schematic plan of the sampling design for conducting butterfly sampling within the study area of the protected forest reserve during the two-year study period.

Rani-Garbhanga Reserve Forest

4.3.2.1 Permanent Line Transects

Prior to the actual data collection, we spent one year in the field (between July – December of 2001 and 2002) constructing a reference collection (now housed at the Laboratory of Entomology and Environmental Biology, Gauhati University, Assam) and familiarising ourselves with the local swallowtail butterfly fauna. Permanent line transects were set up along existing forest paths within the study area (see Photos 4-6).

Each of the 20 permanent transects in both ranges were 1 km long and 5 m wide.

Thus in each study site there were four transects where transects T1 and T2 represented scattered forest (SCF) and transects T3 and T4 represented closed forest (CF). The schematic plan of the sampling design for butterfly sampling within the two-year study period is shown in Fig. 4.3. Table 4.3 shows the distribution of the sampling activities in each of these study sites throughout the dry and wet seasons of the 2-year study period. In the results the study period has been marked as years 1 and 2 (2003-2004) and the multivariate analysis on Papilionidae abundance and distribution pattern and the analysis on Papilionid butterfly diversity is based on the pooled data collected from these permanent transects only.

Table 4.3: Sampling activities in the 50 ha study site of Rani-Garbhanga Reserve forest.

Each day represents 12 transects from three study sites of Garbhanga range and 8 transects from two study sites of Rani range sampled for the dry and wet seasons of 2003 and 2004.

Year 2003 2004

During every transect walk of one km in 30 minutes, butterflies on both sides of the transect within a distance of five metres and up to two metres in front of the observer were recorded. The walking pace was slow but constant and two observers walking together along each transect identified and recorded all butterflies seen. The distance was determined to be the farthest that butterflies could be identified with certainty (using binoculars whenever necessary) at all transects. The distance is greater than most other studies on forest butterflies due to the relatively open forest structure typical of tropical deciduous forests particularly during the dry season (Ghazoul, 2002). Each transect was used twice – forenoon count between 7.00 to 13.00 h and an afternoon count between 14.00 to 17.00 h.

Each of the forenoon transect walks were of 30 minutes duration, while each of the afternoon transect walks were of 15 minutes duration. Although sampling was done on separate days for the study sites of Garbhanga and Rani ranges, the sampling duration for each of the 8 transects from the two study sites in Rani range with respect to forenoon and afternoon counts were the same as that for the transects from the study sites of Garbhanga range. The total sampling hours for the three study sites of Garbhanga range was nine hours and for the two study sites of Rani range was 6 hours. General field observations relating to mud-puddling, foraging, egg-laying were also recorded during the morning hours when the butterflies were most active and in the afternoon for 2 hours (14.00-16.00 hours). The counts from such observations including the amount of time used for handling individuals or recording field notes were not counted towards the sampling effort. Wherever visual identification on the wing was not possible, specimens were netted. Collecting efforts were more concentrated at mud-puddling spots along the stream, sunspots, fallen fruits and in areas near to human habitation where the Papilionids along with the Pierids were found to be attracted to cow-dung and the common nectaring flowers. However it was always ensured that the counts from such spots were located within the transects. Fast-flying canopy species were underestimated as individual counts whenever identification or netting was not possible as the efficiency of the transect method is low for canopy fliers (Spitzer et al., 1993). As a measure of relative abundance of the butterfly species, we used the maximum number of observed individuals in each site. This measure allows controlling sampling intensity and weather differences (Smallidge et al., 1996). All the transect walks were taken on days with favourable weather conditions.

Photo 4 : Study site S1 – Partially disturbed (Garbhanga ) – transect T1 in open/scattered forest (SCF).

Photo 5 : Study site S1 – Partially disturbed (Garbhanga) – transect T3 in closed forest (CF).

T1

T3

Photo 6 : Study site S4 – Heavily disturbed (Rani) – transect T1 in open/scattered forest

Photo 7 : Study site S4 – (Rani) – transect T4 in closed forest (CF).

T1

T4

4.4 Butterfly collection, identification and geographic range classification

The taxonomic characteristics of the swallowtail butterflies were derived using standard keys from literature (Evans, 1932; Talbot, 1939; Parsons & Cantlie, 1947; Wynter-Blyth, 1957; Mani, 1986; Haribal, 1992). The butterflies were collected using nets during the transect walks. Butterflies that could be immediately identified in the field after capture with netting were released while the unidentified specimens were collected in paper packets and taken to the laboratory for stretching and preservation. These were identified with the help of reference material at the Zoological Survey of India, Shillong, India. Type specimens of the collected butterflies were preserved in the laboratory for future reference.

The collected and identified species have also been preserved for photographic references.

However as part of the Conservation policy (National Forest Policy, 1988) over- collection was avoided and some rare specimens were collected only if doubts existed with respect to their specific identity. In the field wherever it was not possible to distinguish between closely related species during flight, such counts were excluded from the samples and analyses. Within the East Himalayan Papilionidae fauna, there are species with two or more different genetic forms such as in case of Common Mormon (Papilio polytes form romulus and Papilio polytes form stichius) and Common Mime (Chilasa clytia clytia and Chilasa clytia dissimilis). During sampling, the individual counts for such species were restricted to the species only without considering the respective forms. As there are several endemic sub-species in the Eastern Himalayas, therefore in case of the nominate sub-sub-species found in Assam and adjoining regions, our sample size was restricted only to individual counts at species level. Similarly for those species, which exhibited polymorphic forms, the counts were taken wherever identification during flight or after netting was confirmed. Again for those species exhibiting mimicry, we did not include the sample counts whenever the identification was not confirmed during flight. In order to avoid sampling bias, another important factor considered was the sex of the different species. Amongst the Papilionidae,

However as part of the Conservation policy (National Forest Policy, 1988) over- collection was avoided and some rare specimens were collected only if doubts existed with respect to their specific identity. In the field wherever it was not possible to distinguish between closely related species during flight, such counts were excluded from the samples and analyses. Within the East Himalayan Papilionidae fauna, there are species with two or more different genetic forms such as in case of Common Mormon (Papilio polytes form romulus and Papilio polytes form stichius) and Common Mime (Chilasa clytia clytia and Chilasa clytia dissimilis). During sampling, the individual counts for such species were restricted to the species only without considering the respective forms. As there are several endemic sub-species in the Eastern Himalayas, therefore in case of the nominate sub-sub-species found in Assam and adjoining regions, our sample size was restricted only to individual counts at species level. Similarly for those species, which exhibited polymorphic forms, the counts were taken wherever identification during flight or after netting was confirmed. Again for those species exhibiting mimicry, we did not include the sample counts whenever the identification was not confirmed during flight. In order to avoid sampling bias, another important factor considered was the sex of the different species. Amongst the Papilionidae,

Im Dokument Diversity and Habitat Selection of Papilionidae in a Protected Forest Reserve in Assam, Northeast India (Seite 76-0)