The elementary unit of nature, an ecosystem, comes into being when two major components of nature, the abiotic or biotope and the biotic or biocenosis, interrelate and influence one another [1]. Physical factors such as light, temperature etc. make up the abiotic component while all organisms are part of the biotic component of nature. Interconnected biotic processes develop largely based on abiotic factors that prevail in an environment. Hence, the two components are inseparable. Providing the planet with an abundant biodiversity and countless other resources, the health of ecosystems is crucial to the survival of humans.

Hazards, mostly anthropogenic, drive an ecosystem to vulnerability i.e. the ecosystem loses its capacity to resist, cope, and recover from the impacts[2]. The consequences, manifested in the form of diminishing services, are an indication of a collapsing ecosystem[3]. A number of ecosystems are faced with this risk mainly because of anthropogenic intervention. A British scientific journal, Nature, has identified forests, alpine and other tundra as vulnerable ecosystems in the current climate change scenario[4].

Regions without trees, dominated by cold climate where snow covers the land for most part of the year, are tundra ecosystems. These ecosystems are divided into three types based on their location. Alpine tundra is found at higher elevations i.e. in mountainous regions. Polar tundra, the Arctic and Antarctic, occur in the Northern and Southern Hemisphere respectively. The climate and environment in these regions is harsh and rainfall is scarce. Wildflowers are common during summer but the land is usually covered in snow. Arctic permafrost is frozen throughout the year, however, during summer, the top layer of permafrost in southern Arctic melts, forming lakes and boglands. It is estimated that Northern permafrost has twice as much organic carbon stored within the soil as in the atmosphere[5].

The average temperature recorded for Arctic tundra varies between -34 to -6°C. Animal species thriving in this temperature range include arctic fox, polar bear, gray wolf, reindeer, snow geese, and muskox. Sheep and mountain goats dwell in alpine tundra[6]. Mosses, lichens, grasses, and short shrubs are the plants commonly found in tundra. Summer period is short with a growing season of about 60 days. While climate change is adversely affecting all ecosystems around the globe, boreal forests and tropical rainforests in some parts of the world as well as Arctic tundra have been identified as the most sensitive ecological systems.

Rising temperatures and shrinking snow cover due to global warming is making the survival of tundra animal and plant species difficult. Several animal species are classified as either vulnerable or endangered. Based on a study for which data was collected from 2000 to 2013, researchers at a Norwegian university found that plants were specifically sensitive to temperature change, water accessibility and even cloud cover.

Subject to climate change, the tundra is experiencing unpredictable impacts. As climate changes, animals migrate into other territories, hence increasing competition for territory and food. An example is that of the red fox which is now competing with the Arctic fox for resources[7]. Similarly, as sea ice is lost, anthropogenic activity will increase, resulting in decreased prey for the beluga whale. The Arctic permafrost, a carbon sink extending 400 meters below surface, is melting due to global warming. As the dead plants decompose, greenhouse gases are released into the atmosphere, thus eventually changing the carbon sink into a carbon contributor. Research on the thawing permafrost is still being conducted and it has been posited that toxic heavy metals such as mercury could be released into the environment if thawing continues.

Global warming remains the prime cause of all these changes. Tundra ecosystems as well as many others can be saved if carbon emissions are cut at both, the individual as well as global level.

About the Author: Marium Shoukat is currently working as a Research Assistant at PCRET while Zainab Imran pursuing Master's degree in RS and GIS at COMSATS, Islamabad.





[3] Guidelines for the application of IUCN Red List of Ecosystems Categories and Criteria, 2016