Comparative Assessment Of Overgrazing And Tourism-Related Land Degradation In The Western Himalaya

The Himalayan mountain ecosystem that has been identified as a global hotspot for biodiversity 1 and serves as the headwaters for several rivers is increasingly experiencing pressure from human activities. Western Himalayas, covering the regions of Himachal Pradesh, Uttarakhand, and Jammu & Kashmir, contains diverse alpine meadows, coniferous forests, and riverine environments that sustain local populations and fauna ranging over long distances³. However, land use change resulting from customary livestock grazing and the expansion of ecological tourism has degraded the land over many years and poses threat to ecological stability and mountain communities⁴.

Land degradation in mountain ecosystems includes loss of vegetation, soil compaction, erosion and biodiversity loss. Overgrazing – a common disturbance caused by excessive grazing on pastures beyond their capacity to sustain animals- is the most common form of disturbance in Himalayas. Altitide pastures called “bugyals” in local terms face the greatest challenge because they serve as summer pastures for migratory livestock from lower elevations, leading to serious trampling and depletion of herbaceous vegetation⁵. On the other hand, trekking, pilgrimage and adventure tourism has given rise to a unique form of anthropogenic disturbance associated with trail erosion, degradation of camping grounds and accumulation of solid waste⁶.

Darma-Byans and Gangotri-Govind landscapes constitute some of the most ecologically diverse but vulnerable regions of Uttarakhand. The Darma-Byans landscape comprises the Darma and Byans valleys in the district of Pithoragarh, whereas the Gangotri-Govind landscape consists of the Gangotri National Park buffer zones and the Govind Pashu Vihar of the district of Uttarkashi. Both landscapes have been subject to high pressure due to overgrazing and tourism activities. However, little is known about the spatial patterns of these degradation phenomena, since systematic, spatially explicit comparative studies on degradation extents have not been carried out. This study aims to fill this gap by using geospatial mapping techniques in the field to identify, measure, and comparatively evaluate sites of degradation due to overgrazing and tourism.

This study seeks to (i) identify and quantify degradation sites due to overgrazing and tourism in the Darma-Byans and Gangotri-Govind landscapes; (ii) identify forest degradation hotspots in the Gangotri-Govind landscape; and (iii) comparatively evaluate the spatial patterns of degradation associated with each activity.

MATERIALS AND METHODS

Study Area

This study was carried out in two landscapes of Uttarakhand, India. The first landscape is that of Darma-Byans (30°05'-30°20'N, 80°25'-80°55'E), which is situated in the district of Pithoragarh and includes many high-altitude villages such as Sipu, Marcha, Tidang, Dugtu, and Garbyang. The Darma-Byans landscape falls in the upper catchment of the Kali (Mahakali) river in close proximity to Indo-Nepal border, comprising of alpine meadows, glacial landforms and transitional conifer-oak forests. On the other hand, the second landscape, that of Gangotri-Govind (30°55'-31°15'N, 78°05'-78°50'E), includes the Gangotri National Park buffer zone and Govind Pashu Vihar Wildlife Sanctuary of Uttarkashi district. The prominent villages of the landscape include Liwari, Osla, Sukki, Jaspur, Jhala, Harshil, Mukhawa, and Satta.

Data Collection

Field surveys were carried out for identification and delimitation of degraded land patches in both landscapes. Selection of field sites was based on prior reconnaissance and consultations with the locals and forest department officials. Geographic coordinates (latitude and longitude) of each site of land degradation were determined through handheld GPS device. The spatial extent of each land degradation patch was measured in the field and expressed in terms of its total area in square metres (m²).

Analysis

The extent of degraded areas was computed per each landscape and for each degradation type. The descriptive statistics such as total area, average size of the sites, minimum size of the sites, and maximum size of the sites were computed for comparative analysis. The extent of degradation was computed as the total area degraded by each driver per landscape.

RESULTS AND DISCUSSION

Degradation caused by Overgrazing in Darma-Byans Landscape

The 15 sites of overgrazing-induced degradation were mapped out of which five villages within the Darma-Byans Landscape were found to have been affected (Table 1). These villages include Sipu (3 sites), Marcha (3 sites), Tidang (4 sites), Dugtu (2 sites) and Garbyang (2 sites). In this landscape, there exists a widespread problem of degradation as a result of overgrazing. The extent of degradation caused by overgrazing in this landscape is estimated to be around 4.19 km² of area while the size of the individual site varies from 11,632 m² (Tidang Site 4) to 1,643,102 m² (Dugtu Site 1). The unusually high site of Dugtu can be attributed to the meeting point of various livestock herding trails in the nodal village of Dugtu. Garbyang Village with its relatively lower elevation close to the Kali river confluence also experiences a high degree of degradation (682,837 m² and 472,059 m²).

Table 1: Degradation Sites Due To Overgrazing In The Darma-Byans Landscape

Overgrazing-Related Degradation in Gangotri-Govind Landscape

Fifteen overgrazing sites have been observed in five villages from the Gangotri-Govind landscape –Liwari (4 sites), Osla (3 sites), Sukki (3 sites), Jaspur (2 sites) and Jhala (1 site) -having a total degraded area of 6.27 km² (Table 2). Liwari and Osla had the maximum degradation area. The Osla Site 2 (1,431,107 m²) is the largest overgrazing site in this landscape. This reflects the heavy load of pastoralism in the Har-ki-Dun valley, which is also used as a popular trekking destination. Similarly, there is significant overgrazing activity in Sukki having three sites with the total degraded area of 2.15 km².

Table 2: Degradation Sites Due To Overgrazing In The Gangotri-Govind Landscape

Forest Degradation in the Gangotri-Govind Landscape

There was another type of forest degradation that was unique only to the Gangotri-Govind landscape with 22 occurrences spread across eight villages (Table 3). The total degraded forest area within this landscape was around 6.27 km², while the largest patch of forest degradation was noted at Satta (1,116,384 m²). The village of Harshil located along the main Gangotri highway corridor had four instances of forest degradation covering an approximate total of 1.92 km². The occurrence of such a situation indicates that the development of infrastructure like roads makes it easier for forest degradation through illegal felling and tourism constructions among other causes. There was a large extent of forest degradation in Mukhawa and Satta villages, both being located along the pilgrimage routes.

Tourism-Related Degradation: Gangotri-Govind and Darma-Byans

Tourism degradation was observed in 7 sites from the Gangotri-Govind landscape and 5 sites from the Darma-Byans landscape (Table 4 and Table 5). In the case of Gangotri-Govind, the areas of individual sites varied from 37,549 m² to 2,384,224 m², which gives a cumulative area of tourism-affected land surpassing 5.32 km². The biggest affected area (Site 1, 2,384,224 m²) belongs to the camping and congregational site in the surroundings of the Gangotri temple. It comprises almost 45% of tourism-related degradation in the landscape due to the intensive influx of pilgrims.

In the Darma-Byans landscape, the cumulative tourism degradation area comprised almost 1.78 km², with an area of 37,549 m² to 682,837 m². It is obvious that the location of several sites close to Garbyang indicates the presence of pilgrimage-based tourism as well. Even though tourism degradation area in this landscape is smaller than the one caused by overgrazing, its distribution is much more compact, which means higher soil compaction and vegetation trampling.

Table 3: Summary -Degradation Area By Landscape And Driver