**6. Causes of biodiversity loss**

The biodiversity losses in the IHR are due to several natural and anthropogenic (man-made) factors. Though natural factors have less effect on biodiversity loss, mitigation of these factors plays a major role since the increased human activities in mountain forests have caused a direct link between anthropogenic and natural factors. Periodic assessment and mitigation of various anthropogenic disturbances affecting Himalayan biodiversity are of crucial importance for the survival of mankind. Anthropogenic disturbances, however, play a major role in shaping the structure of forest stands and landscapes even in remote mountain areas of the world. In India, although the degree of anthropogenic pressure varies in different parts of

the country, the anthropogenic disturbance has become a widespread feature in most of the forests throughout the Himalayas [27]. Humans have extensively altered the global environment by changing global biogeochemical cycles, transforming land, and enhancing the mobility of biota. Many species have been exterminated from the areas dominated by human activities. The causes of decline in the Himalayan ecospheres have been more radical because they are measured as ecologically delicate and the re-establishment of such ruined ecosystems is very complex due to the physical volatility and environmental uniqueness of the area. Any usual or artificial disturbance is a vital force adept of molding plant population structure and dynamics [28]. There are different causes of biodiversity losses in IHR including natural causes (wildfire, drought), Pollution (air, water, and soil), habitat destruction (deforestation, land fragmentation), wildlife trade and hunting, overexploitation of resources, climate change, and introduction of invasive species [29].

Due to the limited employment opportunities and dependence of local inhabitants and tribes, the forest ecosystem is an important source of income for them in the Western Himalayas [6]. Humans are dependent on the forest for their basic needs, such as fuel, food, fodder, cattle grazing, timber, and raw material for forest-based industries and other NTFPs. Rapid demographic changes and over-exploitation of valuable forest resources and plant products have led to the fast-track degradation and destruction of natural flora and fauna of this region. Since IHR consists of a number of religious places and snow-clad hilly stations, it is a major destination for pilgrimage, tourism, and adventure activities which are responsible for causing disturbances in the region. Several developmental projects such as the construction of roads, dams, tunnels, and hydroelectric projects also create excessive disturbances.

In mountainous regions, biodiversity is being vanished or endangered due to land deprivation and the over-exploitation of resources, e.g., IPCC [30] reported that in 1995, nearly 10 percent of the known species in the Himalayas were listed as `*threatened*'. The increasing scale of degradation of bio-resources in the Himalayas [31] has emerged as a conservation priority at the global level [20]. The importance of biodiversity conservation leading toward the sustenance of ecosystem services is a prevailing theme worldwide. The loss of biodiversity has been the part of international policy agenda for several decades [32] and this loss has not stopped yet, and still, we are facing many challenges regarding biodiversity conservation. The biodiversity conservation action and its success vary greatly, depending on the paradigms represented by various professionals in charge of conservation, as well as social-cultural and political context [32].

Beyond habitat degradation, fragmentation, and hunting, other threats to the conservation of biodiversity in protected areas include climate change, invasive species, and interactions between all threats. Mountains are early indicators of climate change [33]. Himalayan regions are one of the few regions where climate change might be rapid and where the penalty of climate change is likely to be as severe for biodiversity, ecosystem services and human well-being [34]. The increase in average temperature is expected to rise higher in the Himalayan region as compared to the global average temperature [35, 36]. A study indicates that the mean annual temperature in the Alaknanda valley (Western Himalaya) has increased by 0.15°C from 1960 to 2000 [37]. Further, climate change modeling studies for India exhibit that the Indian subcontinent is likely to experience an increase in temperature of 3–5°C. Also, anthropogenic pressures have emerged as a major contributing factor for increased vulnerability of the Himalayan

*Biodiversity Conservation of Western Himalayas: A Pluralistic Approach DOI: http://dx.doi.org/10.5772/intechopen.107075*

forests [38]. Such changes in IHR ecosystems are bound to affect the livelihoods of millions of people living in the Himalayas and many more in the adjoining Indo-Gangetic plains those are directly depending on the goods and services of mountain ecosystems for their survival and development [33, 39]. Invasive plant species are likely competent to a particular climate change with assumed impacts on indigenous flora [40, 41]. Manish et al. [42] noticed that native plant species of higher altitudes were largely in danger due to global climate change. This might be attributed due to the reason that these are the elevations with the most confined area coverage [43].
