Environmental Changes and Biodiversity Loss

The present study deals with the environmental changes and biodiversity loss in general and land use/cover change, landslides and biodiversity in Nanda Devi Biosphere Reserve in particular.

It basically deals with the interactions of four basic phenomena, i.e., land use/cover changes, landslides, and biodiversity and biosphere reserve.

Biodiversity is at the core of study while land use/cover changes and landslides are taken as driving forces for biodiversity loss and introduction of biosphere reserves is studied as conservation efforts to conserve the biodiversity and to minimize its loss.

These key terms need to be defined because these terms mean differently to different people and also to mention that to what purpose these terms are used in this study.

Biodiversity refers to the variety of life and its biological diversity on the earth. The numbers of species of plants, animals, micro-organisms, enormous diversity of genes in these species, different ecosystems all are part of biodiversity.

Biodiversity is manifested at three levels:

(a) Genetic diversity—it refers to the diversity within a species;

(b) Species diversity—it refers to the diversity among species; and

(c) Ecosystem diversity—it refers to the diversity of habitats. Land use/cover change has been a prime cause of biodiversity loss. This process has threatened almost all the ecosystems on earth.

Land use includes settlement, cultivation, pasture, rangeland, recreation and so on. Land use change, at any location point, may involve either a shift to a different use or an intensification of existing one. Whereas land cover denotes the physical state of land, for example the quantity and type of surface vegetation, water and earth materials.

Land cover changes fall into two types, conversion and modification. The former is a change from one class of land cover to another, for example from grassland to cropland. The latter is a change of conditions within a land cover category such as thinning of forest or a change of its composition.

A single class of land use corresponds fairly well to a single class of land cover, for example unimproved grassland. On the other hand, a single class of land cover may support multiple uses, for example forest used for combination of timbering, slash-and-burn agriculture, hunting/gathering, fuel wood collection, recreation, wildlife preservation, watershed management and soil protection.

In the present study, both the terms land use and land cover are used interchangeably. Changing land use/cover pattern leads to certain extreme events and may sometimes trigger some natural hazards such as landslides and may lead to biodiversity loss.

Landslide is the sudden movement of soil, weathered rock material or bedrock down the slope, under the influence of gravity often aggravated with water. Weathered material or bedrock after getting detached from the main body slides down the slope very fast.

Landslides are particularly fast when a cushion of air gets trapped beneath the moving mass. As a result, there is no friction between the surface and the moving material. It, therefore, glides like hovercraft. Landslides are very common in young mountains along roads and eroding river banks like in Himalaya.

Slopes of geo-dynamically active Himalayan terrain are made up of complicated geo-structural and topographic set-up. A little imbalance in slope components like geology, geomorphology, geo-hydrology, etc., triggers landslides of various scale and related processes thus cause damage to the natural environment.

Landslide is the product of a number of factors; natural and human and in return landslides signify modification of environment. It leads to land use/cover change as it contributes to wasteland. On the one hand, it leads to loss of natural habitat (forests and grasslands) and on the other it develops new grounds for plant succession, etc. It also results in casualties of animals and human lives.

Biodiversity has been under severe threats due to culture of over consumerism and heavy pressure on natural resources during last century, which has resulted in emergence of variety of ecological disasters. Therefore, biosphere reserves were introduced so that biodiversity can be conserved. Because it is not the individual specie, which is important for the ecosystem but all the species (communities) and their presence is important to keep ecosystem functioning.

Areas rich in biodiversity and encompassing unique features of exceptionally pristine nature and representative ecosystems are identified and designated as biosphere reserves (Srivastava, 1999). The concept of biosphere reserve was initiated by United Nations Educational Scientific and Cultural Organization (UNESCO) in the year 1970 to facilitate conservation of representative landscapes and their immense biodiversity, cultural heritage, foster economic and human development which is culturally and ecologically sustainable.

These areas are internationally recognized within the framework of UNESCO’s Man and Biosphere Programme (MAB). The UNESCO’s framework stipulates that biosphere reserve should be representative of biogeographic province and should have proper zoning system with legally constituted minimal disturbed core zone.

The site should contain unique and pristine biodiversity, ecosystems and landscape suitable to explore and demonstrate approach to sustainable devel­opment. It should be of appropriate size to serve three functions such as conservation, development and logistic support.

Biosphere reserves are designated to deal with one of the most important question of reconciling the conservation of biodiversity, the quest for social and economic development and maintenance of associated cultural values. Conservation of biodiversity promotes economic developments, which are culturally, socially and ecologically sustainable.

Biosphere reserves are divided into three zones for its conservation and management:

1. Core zone:

It is a strictly protected area where human activities are restricted. It provides opportunity for monitoring evolu­tionary changes and serves as a totally protected area for natural regeneration of biodiversity.

2. Buffer zone:

This is the area that surrounds the core zone, where low impact activities are allowed. These include environmen­tally sustainable use of natural resources and development researches, environmental education and regulated recreation.

3. Transition zone:

This zone lying outside the buffer zone where intense, human activities, on sustainable use of resources by local communities are encouraged. It is conceptualized that there is a system in which all four phenomenon are interrelated to each other. The presence of intense human activities alters the ecosystem and its inbuilt self-regulatory system, which influences the living organisms of the biosphere in one way or other.

Change in one element of system results in changes in the other and thus, entire natural system gets disturbed. Land use/cover change is the worldwide phenomenon that has led to disturbance in the entire ecosystem and has drastically disturbed its inbuilt self-regulatory system.

Changing land use/cover pattern, especially in mountain region triggers landslides at various scales and ultimately leads to loss of biodiversity. It poses direct threat to floral diversity in terms of decreasing forest cover or thinning of forest or a change in its composition (habitat loss), which also affects the faunal diversity.

While landslides, due to their devastating nature, destroy biodiversity’s habitat, i.e., forests, thus develop wastelands and alter the natural ecosystem. It also leads to the casualties of animals. Decreasing faunal biodiversity in return may also result in increased landslides.

Thus, changes in any one element of the system intensify the changes in other elements and ultimately in disturbance of entire ecosystem. Thus, conservation efforts are introduced in the form of protected areas such as national parks and biosphere reserves so that biodiversity can be conserved and its loss can be minimized (Figure 3.1).

Biodiversity, living organisms or biotic components of ecosystem has been traditionally studied individually in different disciplines, i.e., botany, ecology, zoology, etc., traditionally studying different parts of biodiversity, i.e., flora and fauna using different research approaches due to which there has been lack of comprehensive view towards ecosystem in general and biodiversity in particular. So, these researches have not actually contributed to preparation of comprehensive strategies for biodiversity conservation.

Thus, the problem of biodiversity loss has been further aggravated in almost every corner of the world. Realizing the fact, no organism can exist by itself or without an environment (Odum, 1971), present study is carried out with multidisciplinary approach so that it can bridge the gap that exists among different disciplines concerned with the research problem taken in this study and to develop a comprehensive view towards the conservation and protection of ecosystem in general and biodiversity in particular.