Climate Change and Species Conservation | Term Paper | Geography

Introduction:

Perhaps the most significant current conservation challenge is represented by climate change. There are increasing concerns on negative impacts of climate change on vulnerable ecosystems in the world and so is in India. Modern global temperature and land cover and projected future temperatures suggest that tropical forest species will be particularly sensitive to global warming.

There are visible impacts of climate change in different ecosystems. Phenology of plants in the Himalayas has changed, for example rhododendron flowering in Eastern Himalaya has been erratic over the past few years. Climate change is not only impacting forests and wildlife, but also human populations which is apparent from a statement issued by WWF in 2008 that reads ‘global warming is melting glaciers in every region of the world thereby putting millions of people at risk from floods, droughts and lack of drinking water’.

Glacier melting will not only endanger the survival of those species inhabiting icy habitats, but also result in changes in water flows and rising sea level causing inundation of islands as well as low productivity of underwater coral reefs. Recent studies have shown that an entire ecosystem on the crumbling ice shelves of the Arctic has been lost due to climate change.

The Eastern Himalaya:

The ecologically fragile Eastern Himalaya in India is part of the Himalaya Biodiversity Hotspot (Conservation International, 2008). This is a resource rich ecosystem providing a multitude of ecological services apart from harbouring a wide range of biological diversity including several endemic species. The forests of the Eastern Himalaya in India are either managed by the State Governments’ Forest Department in the protected areas and reserve forests or are owned by the local indigenous communities who have their traditional customs and regulations to manage them.

The Eastern Himalaya region is highly vulnerable to climate change (e.g. melting of glaciers), with significant impact for entire northeast India as a consequence. Due to the mountainous terrain forests provide indispensable ecological functions and services. In this region local communities still heavily rely on local produce for fuel, food, timber, and other forest products and services. In many instances this has led to overuse and forest degradation.

The need of the hour is enhancement of the protected area management, thereby improving biodiversity conservation; restoration of forest cover and unique forest ecosystems; absorbing additional amounts of atmospheric carbon through restored forest stands; improved and sustained supply of forest products (wood and non-wood) to local communities; regulation of watersheds and enhancement of biodiversity and erosion control, especially in hilly areas; development of replicable pilots for adaptation to climate change and development of adequate adaptive resource management strategies for vulnerable ecosystems in India.

Are Tropical Species more Vulnerable?

Wright et al. (2009) suggested that wild species’ response to global warming would be manifested through acclimation, evolutionary adaptation and range shifts to cold refuges. There is a trend of temperature increase of an average 0.26°C per decade since 1970s in the tropical areas. To escape global warming, the temperature sensitive species may disperse to cool refuges.

A major deciding factor for this dispersal is the distance to cool refuges which is largest near the equator, shortest for mid-temperate latitudes and large for north temperate and arctic latitudes. Distances to refuges are more than 2000 km in some tropical mountain areas like the Western Ghats in India. As species abundances change in response to climate change, the influences of negative density dependent factors on their vital rates will shift accordingly, stabilizing the new communities.

Latitude more Determining than Longitude:

Species’ ability to respond to global warming is likely to vary with latitude because of four factors due to latitudinal differences; these are expected increase in temperature, inherent sensitivity of species to temperature change, proximity to cooler refuges and the potential for interaction with species adapted to warmer climates. Wright et al. (2009) suggested that species in the low latitude areas are likely to be more sensitive to temperature change.

According to Terborgh (1973), lowland mean annual temperatures range from 24-27°C in a 31 million sq km area and 47° of latitude between the Tropic of Cancer and Tropic of Capricorn. Plant communities in the tropical regions are not likely to adapt well to climate change and as a result the animals depending on them will be affected. Deutsch et al. (2008) found that warming in the tropical areas, despite being small in magnitude is likely to have severe consequences as the insects inhabiting this region are relatively sensitive to temperature change and the present temperature here is close to their optimal range.

Inadequate capability of tropical species to acclimate to global warming is going take its toll in the tropics over a longer period. Since the tropical areas have a greater concentration of species, any shrinkage in their habitat resulting from climate change would have detrimental effect on the population. Deutsch et al. (2008) tested frogs, lizards and turtles using published documents where critical thermal limits were experimentally determined for at least 12 population of closely related taxa across large climate gradients.

They found that in each taxonomic group, warming tolerance of an organism increases strongly with the seasonal temperature variability of its habitat, which indicates that warming will cause tropical vertebrate ectotherms to approach their critical maximum temperatures proportionately faster than similar species inhabiting the higher latitude areas.

As a consequence, these taxonomic groups will likely experience severe changes in thermal performance during global warming. Bush (2002) suggested that as global temperature increase, immigrants from warmer areas are likely to be better adapted to new and warmer climates than are the original residents of the former cooler areas.

Species in the mountains in the tropical region are to be mostly affected because the surrounding lowlands provide a nearby source of species adapted to warmer climates; however, lowland tropics would not be threatened by the arrival of species adapted to warmer climates as this area already supports the highest mean annual temperature and species adapted to warmer climates are not here originally.

Considering 5,257 terrestrial mammalian species after Schipper et al. (2008) and their habitat associations as per the IUCN Red List (IUCN, 2008), Wright et al. (2009) came up with a total of 4,351 terrestrial mammalian species that are fully or partly distributed in the tropical latitudes; out of which a total of 2,814 species had ranges restricted to tropical latitudes and among these 1,224 species were restricted to the narrow belt of low-latitude tropics (10″N to 10″S). Wrights et al. (2009) described these later 1,224 species to be sensitive to global warming.

The Case of Flagship Species:

The most accepted hypothesis is Bengal tigers (Panthera tigris tigris) dwelling the mangrove islands of Sundarbans in Bangladesh and India face severe threats from climate change. Agarwala et al. (2003) and Mohal et al. (2005) predicted that permanent inundation, drainage congestion, salinity intrusion and more frequent storm induced inundation would be probable climate change impacts in the Sundarbans.

Since these mangrove islands, which are also habitats for tigers and their prey, are surrounded by high density human habitations, except the southern side which has Bay of Bengal, the chance of these animals’ dispersal into safer and higher grounds is very slim and is also going to increase the thriving human – tiger conflict. Tigers are no safer from effects of climate change outside Sundarbans. Beniston (2003) and Cruz et al. (2007) have noted impacts of climate change in the greater Himalayas and it is highly likely that the two major rivers, Ganga and Brahmaputra, arising out of this region will also bear the brunt of these impacts.

Cruz et al (2007) predicted a decline of water flow in these rivers due to diminishing glacial ice source over long term resulting in water shortage for downstream wildlife. They also suggested that the two above-mentioned rivers could have seasonal flows in near future. As vast extent of grasslands and riparian habitats are supported by these two rivers’ downstream flows which constitute important habitats for tigers and their prey in India and Nepal, climate change is surely going to impact the population thriving there.

As mentioned above, impacts of climate change on the grasslands and riparian habitats of tigers and their prey are also going to have adverse impacts on populations of Asian elephant (Elephas maximus). This is reiterated by Seidensticker (2008) who noted that changes in river hydrology with reduced runoff will impact the forests and grasslands found along the outer range of the Himalayas, in the Shivalik hills and the associated narrow strip of lowland forests in the bhabar and the terai.

Most affected areas will be the Terai Arc Landscape from the river Yamuna in India in the west to river Bagmati in Nepal in the east that is spread in the Indian states of Uttarakhand, Uttar Pradesh and Bihar and adjoining low-land areas of Nepal; the dooars in northern part of West Bengal and the Bramhaputra floodplains in Assam starting from Manas National Park in the west through Pobitora Wildlife Sanctuary, Kaziranga National Park, Laokhowa-Burachapori Wildlife Sanctuary, Nameri National Park to Dibru-Saikhowa Wildlife Sanctuary.

The Indian rhinoceros (Rhinoceros unicornis) are also affected by the stresses in grassland habitats as mentioned in case of elephants. In addition, rhinos are also affected due to flood in their prime habitats, more so in Kaziranga National Park and Pobitora Wildlife Sanctuary in Assam, India.

Remarks:

Tigers, elephants and rhinos which are already threatened by poaching because of a thriving demand for trade in their body parts, high level of human-animal conflict and resulting retaliatory killing, habitat fragmentation and loss of corridors due to agricultural expansion, rapid human population growth and an unplanned development regime are going to be less resilient to impacts of climate change. Hoods add another stress to the already threatened species.

Animals from flood inundated areas migrate to higher grounds in search of dry land and in doing so, sometimes disperse out of the protected areas where there safety is compromised; they either come in conflict with human beings, get killed or hit by trains and speeding vehicles.

Climate change might not be reversed, but global warming can be kept within tolerable limits if proactive actions are taken right away. The first path towards this is to reduce emission of greenhouse gases including CO₂. It is a fact that CO₂ is released during burning and combustion of fossil fuels such as coal, oil and natural gas required for transportation or production of electricity. Most damaging is coal as it produces 70 per cent more CO₂ emissions than natural gas for the same energy output.

Electricity generation is the single largest source of manmade CO₂ amounting to 37 per cent of worldwide emissions (WWF, 2008). To reduce these emissions, WWF is calling for actions that include improving the energy efficiency of power plants; increasing use of renewable energy sources; stopping investment in new coal plants and coal mining; making consumers aware to use green power and energy efficient appliances; and requesting policy makers to ease the transition to a carbon-free energy industry by passing suitable legislation that creates favourable market conditions and ensure that the ‘Kyoto Protocol’ enters into force as soon as possible.