0357-B3

Forest Biodiversity Conservation Study of Indian Himalayan Eco-sensitive Sites

Vijita Kumari and Sas. Biswas ¹

Abstract

The various human activities have been largely responsible for the environmental degradation. As the degradation in environment is not due to only one factor at a time, thus there is a need to shift the strategy of environment management from traditional approach to the holistic approach of management. Many disasters are either caused or exacerbated by environmental degradation. Either it is environmental degradation or its consequences biological diversity is being lost at each and every step of the environmental degradation. In the present work the major damaging activities as- mining, invasive alien species and soil erosion in the eco-sensitive Doon valley and surroundings were considered for the study. Biodiversity statuses of the area have been calculated by using Shannon-Wiener diversity index and IVI and different species of the area have been categorised with the help of Braun Blanquet frequency classification. On the basis of field study and literature review suitable site-specific strategy have been recommended to control the biodiversity loss in that area.

Introduction

Environmental degradation is decay in environmental quality and loss of biodiversity with the passage of time. It can also be called as disturbance in the environmental components i.e. biotic and abiotic factors of an area. Factors for this degradation are many. It may be natural or man induced.

There are various elements of environmental degradation like soil erosion, air and water pollution, noise pollution etc. which have their individual detrimental effects but their cumulative effect is much more devastating. This can be pictured in the ecosystem health, biodiversity status, forest productivity, interrelationship between different trophic levels.

Environmental degradation in Doon valley in Indian himalayan region is not due to just one or two kinds of activities but is the cumulative result of various kind of human activities and also to some extent due to natural phenomenon like excessive runoff due to cloud burst, high intensity rainfall caused by La-Niña, global climatic changes etc. Some of the human activities are mining, increasing infrastructure due to increased population, agricultural activities, road development, encroachment in forestlands, interferences of biotic components with natural inhabitants of the area etc.

The climatic and altitudinal condition of India harbours a wide range of ecosystem. India's fabulous biodiversity is estimated to be over 45,000 plant species representing about 7% of the world's flora; and it's bewildering variety of animal life represents 6.5% of world's fauna (Agarwal, 2002). Damage to the environmental quality leads to the loss of biodiversity at the very fast rate. This loss of species can make voids in the food web and consequently disturbance in the balance of the ecosystem.

The four key characteristics of degradation are-structure, density, species composition and productivity- provides a good starting point for defining a set of physical indicators that can be used to distinguish the degraded environment. Many disasters are either caused or exacerbated by environmental degradation.

Objectives

The objectives of the present studies were as follows:

1. Assessment of environmental degradation due to specified activities.
2. Study the impact of degradation on the biodiversity of the surrounding area.
3. To evolve suitable site-specific strategies for the prevention and control of impacting pressure on the biodiversity.

Significance of the investigation

Indiscriminate human activities are causing environmental degradation since very long. These degradations are not the result of a single developmental activity but are the cumulative result of industrialization, haphazard development and unsustainable utilization of natural resources of the area.

So there is need to develop economical and practical criteria and indicator of environmental status of an area. Some of these can be rate of soil erosion, water and air quality, biodiversity status etc.

Study Area

Doon valley is distinct unique ecosystem in the foothills of Himalayas. The valley is bounded on the North-East by Lesser Himalayan belt, on the South-West by the Siwalik The average length and width of Doon valley is about 70 km and 20 km respectively. Geographically it falls between 77^o35' to 78^o35' East longitude and 27^o 35' to 30^o North latitude. The mean average altitude is approximately 650 m. The Ganga and the Yamuna, demarcate South-Eastern and North-Eastern boundaries.

Forest types are diverse ranging from temperate to tropical dry deciduous forest. Floristic composition of Doon valley determines it as a predominantly Sal forest region. Interestingly Sal forest types of the area such as Rajaji National Park are further subdivided into as many as seven types.

As a result of 1991 census the total population of Dehra Dun district stood at 10.26 lakh and as per the 2001 census the total population is 1,279,083. So the increase in population in the 10-year period is about 200,000.

Selection of the Study Site:

The selection of the area for the study is based on the available literature, land use changes and subsequent land degradation in the past. The choice is also based on the availability of remote sensing data products and other base material. For the study three areas were selected as under

Study area I: Abandoned Lambidhar limestone Mine (Mining activity)
Study area II: Sahastradhara valley (Invasive Alien species)
Study area III: Sal Forest Silaqui (Soil Erosion). Two sites were selected, degraded Sal forest as Stand I and natural Sal forest as Stand II.

Materials and Methods

Study Area I

Preparation and finalization of the base map of the area from the satellite imagery and SOI toposheets; this is done by visual interpretation of Landsat-TM images, followed by standard interpretation techniques.

During the survey plots were selected in different areas and quadrates were laid out. This was done randomly. Nested quadrate method was used for laying the quadrates. For tree species the size of quadrate taken was 10m x 10m. Within this sub quadrates of 3m x 3m and 1 x 1m were laid to record the shrubs and herbs respectively. In each quadrate, counted the number of species encountered and circumference at breast height (cbh) i.e. 1.37m from ground, of all tree species was recorded. Average girth of each individual of shrub species was recorded. For herbs only the number of individuals of each life form was recorded. Besides this the near by local people were questioned about other information regarding the study.

The data collected from the Lambidhar mine was analysed and based on that a list of species was prepared. For each species Importance Value Index (IVI) was calculated.

Study Area II

The main invasive alien species in the area were Lantana, Parthemium, Tithonia, Eupatorium and Ageratum. No animal invasive was noted in the area. Quadrate of 5 x 5 m was used for the study of invasive species because they were basically shrubs and 10 x 10 m of quadrate was laid out for the data collection in the ecotone region as there were tree species also occurring in the area. 5 x 5 m quadrates were laid by visualizing where the particular invasive is dominating. In each 5 x 5 m quadrate number of mature individuals, number of immature individuals and seedling/regenerating were counted for the invasive species. Other species in the quadrate was also noted down. Other information noted were some of the physical properties of soil (colour, texture, main components, humus status and litter), faunal species present in the quadrates, phenology of the invasives, its pollinators and any other threat perception in the area of study.

Data obtained is represented in the tabular form for making a comparison of the effect of each species on the ecosystem.

Study Area III

For the study of soil erosion two sites were selected; degraded and undegraded. Ten quadrates (10m x 10m) were laid down at each site the species, number of individuals of each species and their cbh were recorded. A 3 x 3m quadrate was marked within each of the 10 x 10 m quadrate where shrubs, sapling, amphibians and reptile were collected and identified. A 1 x 1m quadrate was marked within the 3 x 3m quadrate for sampling herbs, soil organisms and seedlings. Migratory species mammals, birds and butterflies were sampled using a line transect of 200 m. Twenty monitoring were made with line transect method.

The data were analysed for frequency and Shannon-Wiener diversity index. This index measures diversity by the following formula:

Where, H= the diversity of species
S= the number of species
Pi= proportion of individuals of the total sample belonging to the i^th species.

This index takes into considerations the number as well as the relative abundance of species.

The species on the basis of its percentage frequency are classified into five classes as proposed by Braun Blanquet.

i. Rare - present in 1 to 20% of the sampling units.
ii. Seldom present - present in 21-40% of the sampling units.
iii. Often present - present in 41-60% of the sampling units.
iv. Mostly present - present in 61-80% of the sampling units.
v. Constantly present - present in 81-100% of the sampling units.

Diversity index is used to know the homogeneity or heterogeneity of the ecosystem. Higher the diversity index higher will be heterogeneity. A community that contains a few individuals of many species will have a higher diversity than will a community containing the same number of individuals but with most of the individuals confined to a few species.

Result and Discussion

Mining:

Areas calculated by remote sensing techniques for different land use pattern are given in Table 1.

Table 1: Area under different land use pattern in the year 1985 and 1996

Phytosociological study shows that among tree species Alnus is having the highest IVI (refer Graph 1), among shrubs the species with highest IVI is Princepis utilis (refer Graph 2) and in herbs there were many species having more or less similar frequency (refer Graph 3). The herbs have occupied the larger area because of the climatic condition of the area.

The high altitude and the microclimate of the area greatly affect the distribution of plants and animals. The effects are due to change in the climatic conditions. With the rise in altitude, the temperature decreases, rainfall increases and wind velocity also increases, and all these affects development of soil and vegetation. Generally chamaeophytes occur at higher altitudes. The trees have not attained the proper height.

From the literature review, many species which occurred but now unavailable in the area are: Pittosporum eriocarpum, Sageretia oppositifolia, Saphora mollis, Dalbergia sericea, Brassaiopsis aculeate, Leptodermis lanceolata, Tylophora himalaica, Barleria cristata, Sapium insigne, Olea glandulifera, Periploca calophylla etc. In the addition to these, a lot of pteridophytic ferns, mosses and algal plants disappeared due to drying of water resources after mining and querrying. The loss of habitat has compelled monkeys, langures, wild boars and hares to raid the farmer's crops.

Invasive Alien species:

The result of the field study shows higher number of species in the ecotone area and lesser species in the invaded lands. Quadrate IV whose principle species was Lantana was having very few species; (refer Table 2) this is because of the allergic and allelopathic effect of this obnoxious weed also because the canopy of Lantana is very dense, not allowing light to reach the floor.

The result of the field study shows higher number of species in the ecoton area and lesser species in the invaded lands. Quadrate IV whose principle species was Lantana was having very few species; this is because of the allergic and allelopathic effect of this obnoxious weed also because the canopy of Lantana is very dense, not allowing light to reach the floor.

Although there were insect and bird species in the alien invaded areas but these are very few and only selected species, for example the only bird in the area seen was Red Vented bulbul. This bird is the pollinator of Lantana flower and is seen in the area only during the flowering season of Lantana.

In quadrate I, II, III and IV only one individual of two tree species were present which were Acacia catechu and Flecourtia indica. Seedling and sapling of the tree species were seen but were unable to attain the height of a proper tree.

Table 2: List of other species in the quadrates.

Soil Erosion:

Shannon-Wiener diversity index for degraded Sal area is 2.6345 and for the forest area unaffected by soil erosion of Selakui Sal forest is 3.23483. Comparison of Braun Blanquet frequency classes for the species of forest areas affected by soil erosion and not affected by soil erosion is given in Graph 4. During fieldwork other threat to the biological wealth of the area were also seen. Among them invasive alien species, grazing, brick kilns are worth to mention.

By analysing the result of three study sites receiving the environmental degradation we can conclude that above activities have resulted in considerable threat to the biodiversity of the area.

Due to erosion the density of Sal trees were reduced and the stumps were left. The termite mounds were seen in such areas. They feed on the cellulosic wastes left after erosion. Birds were not observed in the area of soil erosion because of unavailability of shrubs and the insects in the area.

Recommendation

Recommended measures are as follows:

Mining should be excluded from areas, (i) vulnerable to excessive erosion, (ii) tourist and vacation resorts, (iii) water sources, (iv) ecologically fragile areas etc.

The research is needed to:

• Finding out suitable tree, shrub, grass species for site improvement, afforestation and landscaping by plant introduction trials and ecological surveys.
• Finding out the most suitable soil working and planting techniques for establishing these species.
• Finding out the most practical and economic way of protecting these plantations against grazing, fire and theft.
• Finding out the suitable method of back filling and grading the overburden.
• Finding out the most effective way of checking surface erosion and stream pollution.
• To quantity the different environmental hazards resulting from mining industry.

With reference to the invasive alien species further information is needed on the predictability of biological diversity from environment and history, on the dependence of ecological function on diversity, and on the historic and spatial contingencies present.

For eradication of invasive alien species, its interaction attribute with present ecosystem needs to be modelled. This is function of place of invasive alien species in food web, prey-predator relationship. Its mode of reproduction, its dependence on pollinators, phonological cycle etc. This information will help in forecast where next invasion in going to take place: in terms of its extent and its intensity. Secondly, adopting integrated pest management (IPM) in the established natural resource management plan so that the structure and composition of the ecosystem is not altered.

In soil erosion control, there is much to be learned about erosion mechanism and the erosion control practices that are used to prevent it. Using proper erosion control techniques, utilizing the surrounding environment, and employing simple technology are all Best Management Practices that will enable us to maintain the fertility of the land and protect the biodiversity and thus to maintain the ecological balance.

Reference:

Agarwal S.K. (2002). Biodiversity. Biodiversity and Environment. Eds: S.K. Agarwal, Swarnlata Tiwari and P.S. Dubey. A.P.H. Publishing Corporation. :1-60.

Dhar, B.B. (2000). Mining Environment Scenario Beyond 2001. Mining Challenges of The 21^st Century. A.P.H Publishing Corporation: 73 - 92.

Hindmarch, T. D. and Reid, M. L. (2001). Thinning of mature lodgepole pine stands increases scolytid bark beetle abundance and diversity. Cannadian Journal of Forestry. Res. 31: 1502-1512.

Usher, M.B. (1991). Biological Invasion In the Tropics Nature Reserves. Ecology Of Biological Invasion In The Tropics. Eds: P.S.Ramakrishnan. Interonal Scientific Publications. :21-31.

Vasudevan, P. and Jain, S.K. (1991). Utilization of Exotic Weeds: An Approach To Control. Ecology Of Biological Invasion In The Tropics. Eds: P.S.Ramakrishnan. Interonal Scientific Publications.:157-175.

Verma R. K. Shadangi D. K. and Totey N. G. (2001). Analysis of Biodiversity and Improvement in Soil Quality Under Plantation on Degraded Land. Indian Journal of Forestr 24 (1): 21-28.

Wright, L. (1993). Soil and The Human Impact. Environmental System and Human Impact. Cambridge University Press: 32-38.

¹ Botany Division, Forest Research Institute
Dehradun-248006, Uttaranchal, India
Tel: 0091-135-756821 & 750648
E-mail: [email protected] & [email protected]