Fragile ecosystems are systems that are highly sensitive to changes in surrounding environmental conditions like air, water quality, temperature, and others and are basically seen all over the earth and include both aquatic and terrestrial habitats. Terrestrial habitats prone to fragility include mountains, rain forests, and floodplains while aquatic habitats include oceans, estuaries, river systems, ice-capped mountains, and other lentic water bodies such as seas, dams, etcetera. Slight disturbance to these fragile ecosystems might cause big damage. Having said that, I would like to begin my letter referring to what the 14th October 1995 issue of New Scientist (NS) has to say on fragile ecosystems.
F. G. Grisley in an issue of your journal, NS indicated that low diversity ecosystems are more fragile than ecosystems with high diversities (Letters, 14th October), an idea that I agree with some reservation. Ecosystems with high bio-diversity can resist calamities or any happenings unnatural to the systems more than those with low biodiversity. The Correspondent talked about the toxic waste dumped in an ecosystem and squarely signposted that toxic waste should not be thrown in an ecosystem that has low biodiversity as there is the possibility of that particular system being collapsed owing to its fragility. However, depending on the resilience capacity, an ecosystem with low biodiversity may be able to bounce back to equilibrium or resist better than one with high biodiversity.
As such, it must be agreed that the fact is not so simple. Nelson and Grelsson in their 1995 paper on ecosystem fragility regarded fragility as an inverse of stability and indicated that they depended on several components. Fragility is defined by communities, species, or ecosystems that are potently likely to be compromised by anthropogenic pressures which could be an ecosystem with high bio-diversity or low biodiversity. Therefore, rather than considering ecosystem fragility or stability which is based on low or high biodiversity, it is the resilience and resistance of ecosystems that are important for management decision-making.
Fragility is an innate property of any ecosystem. Whether an ecosystem is exposed to anthropogenic and or natural disturbances or not, they have certain fragility associated with them. Therefore, the NS Correspondent’s hint to dispose of toxic waste in an ecosystem with low biodiversity may not be such a good idea as at the determinable level, the same quantity of ecosystem will be discredited, whether it has high or low biodiversity.
But the question is where to dispose of the toxic waste? Toxic wastes can harm any system. In a scenario like this, where dumping toxic waste is unavoidable, choosing an ecosystem with evident and succinct species boundaries and not necessarily the ones with the lowest biodiversity must be chosen, as the such choice might help hold some diversity.
One fact about ecosystem fragility is that it cannot be quantified but only assessed based on the disturbances caused to the ecosystem by human activities or natural forces. Fragility or stability is based on the transformation in species abundance and composition, after disturbances to the ecosystems, which alter species dynamics.
Based on the anthropogenic disturbances, which are primarily global warming that is caused due to emissions of greenhouse gases (GHG) and many other such activities, at the global level, scientists have described different types of capabilities shown by the ecosystems, whether fragile or stable and coined words like resilience, resistance, and persistence.
An ecosystem is said to be resilient when it can return to equilibrium after a disturbance. An example of such an ecosystem is the Great Barrier Reef Ecosystem where coral reef habitats and populations like coral reefs, coral trout, humpback whales, and lagoon floor are recuperating post-disturbance.
Another term used to describe an ecosystem is resistance which is the ability of an ecosystem to resist change. In a resistant ecosystem, disturbances might transform a component completely, but the aftermaths to the ecosystem as a whole may not be substantial. An example of such resistance is that shown by the Himalayan Snow Lotus (Saussurea laniceps), which has become smaller to fight human-induced disturbances.
A more specific example of a resistant ecosystem is the Chirpine forests (Pinus roxburghii) of eastern Bhutan which is subjected to man-made fires for lemon grass oil production. The lemon grass harvesters deliberately burn the forest in winter (Figure 1) so that they get good and productive grasses in the summers for oil production. However, the Chirpine forest resists the fire to come into shape the next season and lets the grasses grow underneath as usual. While other effects on the forest due to burning needs deeper studies, the visible physical appearances of the forest do not change post-fire hazard, indicating that it can resist forest fires.
There is yet another term used for gauging the ecosystem’s fragility is persistence, which is regarded as the time taken for an ecosystem to transform into another type of value or ecosystem. An ecosystem is said to be persistent if it can remain unchanged over a longer period due to disturbances natural or anthropogenic.
Whatever the terms coined and explained above, the composite nature of ecosystem fragility or stability does not alter much because the various aspects of fragility or stability are not necessarily completed. One factor of an ecosystem may be fragile while all other factors are stable. Fragility is not quantifiable and they depend on taxonomic and numerical results and temporal and spatial scales.
The taxonomic composition of species in an ecosystem might change without changing the relative abundances because a species might be disappearing while another species might be emerging. Also, species numbers might fluctuate depending on the ecosystems’ condition and the number of individuals of a species in the ecosystem may be diminishing while some species numbers may rise.
On a time scale, an ecosystem may be extremely fragile from a short-term standpoint while it has remained stable over many years. An example of Chirpine forest burning in Eastern Bhutan (Figure 1) befits this. The long-term stability of the forest ecosystem is predictable while it appears unstable when the forest gets burnt every year. An ecosystem might appear fragile because of its small size, but it may not be the case if bigger spatial scales are considered. In fact, local disturbances may be required to ascertain stable regional-level ecosystems. Therefore, fragility and stability can be defined only on scales and not impromptu.
Major factors rendering the ecosystems fragile are population growth, extensive exploitation of natural resources, intensive agriculture, planned urbanization, industrialization, unscientific resources use that are responsible for the sinking of the water table, lowered availability of resources, pollution, increased incidences of disasters, poverty, and high price rise, etcetera.
As such, scientists, based on the few decades’ time scales have identified at least nine fragile ecosystems on the earth's surface, from fading ice layers and shrinking rainforests, to flash floods and water shortages, the most important of all being the Arctic sea ice mass and the Greenland ice layers which are under imminent threat, primarily due to global warming. Climate scientists have asserted that there would be no masses of sea ice in the summers within the next two and half decades. So, it is for the existing Homo sapiens to evaluate how fragile our ecosystem has become and act accordingly.
Another fragile ecosystem with an impending threat is the Amazon rainforest. Scientists urged that the vegetation cover of the rainforest would not be recovered due to minimized rainfall. They are also apprehensive about the Boreal forest of the north which influences El Niño and recommended for establishment of early warning systems for each of these fragile ecosystems so that they can be monitored and necessary actions taken as and when required. Besides the identified fragile ecosystems, many other systems are under threat from global warming caused by human actions.
Therefore, steps to mitigate the threats to the fragile ecosystems must be initiated by the global powers as well as the developing countries emitting gases that are harmful to the earth’s fragile ecosystems. Improved and proactive planning by all stakeholders to reduce GHG and carbon emissions, control water use, cut energy demand, and advocate renewable and environmentally favorable energy sources must be put in place to save the fragile ecosystem.
The identification of fragile ecosystems by scientists worldwide does imply that the earth does have ecosystems that are actually fragile that they may tip at any time. Therefore, I agree with the paradigm of a fragile ecosystem.
However, as the paradigm is complex, I would like to conclude my letter by agreeing with D. A. Radcliffe (1976), who quoted, “the magic of the natural world beckons and challenges, and lures the receptive soul ever onwards but, like the Holy Grail, it is never finally found and possessed. And this is its fascination.”
F. G. Grisley in an issue of your journal, NS indicated that low diversity ecosystems are more fragile than ecosystems with high diversities (Letters, 14th October), an idea that I agree with some reservation. Ecosystems with high bio-diversity can resist calamities or any happenings unnatural to the systems more than those with low biodiversity. The Correspondent talked about the toxic waste dumped in an ecosystem and squarely signposted that toxic waste should not be thrown in an ecosystem that has low biodiversity as there is the possibility of that particular system being collapsed owing to its fragility. However, depending on the resilience capacity, an ecosystem with low biodiversity may be able to bounce back to equilibrium or resist better than one with high biodiversity.
As such, it must be agreed that the fact is not so simple. Nelson and Grelsson in their 1995 paper on ecosystem fragility regarded fragility as an inverse of stability and indicated that they depended on several components. Fragility is defined by communities, species, or ecosystems that are potently likely to be compromised by anthropogenic pressures which could be an ecosystem with high bio-diversity or low biodiversity. Therefore, rather than considering ecosystem fragility or stability which is based on low or high biodiversity, it is the resilience and resistance of ecosystems that are important for management decision-making.
Fragility is an innate property of any ecosystem. Whether an ecosystem is exposed to anthropogenic and or natural disturbances or not, they have certain fragility associated with them. Therefore, the NS Correspondent’s hint to dispose of toxic waste in an ecosystem with low biodiversity may not be such a good idea as at the determinable level, the same quantity of ecosystem will be discredited, whether it has high or low biodiversity.
But the question is where to dispose of the toxic waste? Toxic wastes can harm any system. In a scenario like this, where dumping toxic waste is unavoidable, choosing an ecosystem with evident and succinct species boundaries and not necessarily the ones with the lowest biodiversity must be chosen, as the such choice might help hold some diversity.
One fact about ecosystem fragility is that it cannot be quantified but only assessed based on the disturbances caused to the ecosystem by human activities or natural forces. Fragility or stability is based on the transformation in species abundance and composition, after disturbances to the ecosystems, which alter species dynamics.
Based on the anthropogenic disturbances, which are primarily global warming that is caused due to emissions of greenhouse gases (GHG) and many other such activities, at the global level, scientists have described different types of capabilities shown by the ecosystems, whether fragile or stable and coined words like resilience, resistance, and persistence.
An ecosystem is said to be resilient when it can return to equilibrium after a disturbance. An example of such an ecosystem is the Great Barrier Reef Ecosystem where coral reef habitats and populations like coral reefs, coral trout, humpback whales, and lagoon floor are recuperating post-disturbance.
Another term used to describe an ecosystem is resistance which is the ability of an ecosystem to resist change. In a resistant ecosystem, disturbances might transform a component completely, but the aftermaths to the ecosystem as a whole may not be substantial. An example of such resistance is that shown by the Himalayan Snow Lotus (Saussurea laniceps), which has become smaller to fight human-induced disturbances.
A more specific example of a resistant ecosystem is the Chirpine forests (Pinus roxburghii) of eastern Bhutan which is subjected to man-made fires for lemon grass oil production. The lemon grass harvesters deliberately burn the forest in winter (Figure 1) so that they get good and productive grasses in the summers for oil production. However, the Chirpine forest resists the fire to come into shape the next season and lets the grasses grow underneath as usual. While other effects on the forest due to burning needs deeper studies, the visible physical appearances of the forest do not change post-fire hazard, indicating that it can resist forest fires.
Figure 1. Chirping forest under fire in Trashigang District, Bhutan. Quite often, such fires are set to produce quality grasses for oil production. But the forests resist and show very less damage to their health. (Photo: Jigme Tshelthrim Wangyal, 2013).
There is yet another term used for gauging the ecosystem’s fragility is persistence, which is regarded as the time taken for an ecosystem to transform into another type of value or ecosystem. An ecosystem is said to be persistent if it can remain unchanged over a longer period due to disturbances natural or anthropogenic.
Whatever the terms coined and explained above, the composite nature of ecosystem fragility or stability does not alter much because the various aspects of fragility or stability are not necessarily completed. One factor of an ecosystem may be fragile while all other factors are stable. Fragility is not quantifiable and they depend on taxonomic and numerical results and temporal and spatial scales.
The taxonomic composition of species in an ecosystem might change without changing the relative abundances because a species might be disappearing while another species might be emerging. Also, species numbers might fluctuate depending on the ecosystems’ condition and the number of individuals of a species in the ecosystem may be diminishing while some species numbers may rise.
On a time scale, an ecosystem may be extremely fragile from a short-term standpoint while it has remained stable over many years. An example of Chirpine forest burning in Eastern Bhutan (Figure 1) befits this. The long-term stability of the forest ecosystem is predictable while it appears unstable when the forest gets burnt every year. An ecosystem might appear fragile because of its small size, but it may not be the case if bigger spatial scales are considered. In fact, local disturbances may be required to ascertain stable regional-level ecosystems. Therefore, fragility and stability can be defined only on scales and not impromptu.
Major factors rendering the ecosystems fragile are population growth, extensive exploitation of natural resources, intensive agriculture, planned urbanization, industrialization, unscientific resources use that are responsible for the sinking of the water table, lowered availability of resources, pollution, increased incidences of disasters, poverty, and high price rise, etcetera.
As such, scientists, based on the few decades’ time scales have identified at least nine fragile ecosystems on the earth's surface, from fading ice layers and shrinking rainforests, to flash floods and water shortages, the most important of all being the Arctic sea ice mass and the Greenland ice layers which are under imminent threat, primarily due to global warming. Climate scientists have asserted that there would be no masses of sea ice in the summers within the next two and half decades. So, it is for the existing Homo sapiens to evaluate how fragile our ecosystem has become and act accordingly.
Another fragile ecosystem with an impending threat is the Amazon rainforest. Scientists urged that the vegetation cover of the rainforest would not be recovered due to minimized rainfall. They are also apprehensive about the Boreal forest of the north which influences El Niño and recommended for establishment of early warning systems for each of these fragile ecosystems so that they can be monitored and necessary actions taken as and when required. Besides the identified fragile ecosystems, many other systems are under threat from global warming caused by human actions.
Therefore, steps to mitigate the threats to the fragile ecosystems must be initiated by the global powers as well as the developing countries emitting gases that are harmful to the earth’s fragile ecosystems. Improved and proactive planning by all stakeholders to reduce GHG and carbon emissions, control water use, cut energy demand, and advocate renewable and environmentally favorable energy sources must be put in place to save the fragile ecosystem.
The identification of fragile ecosystems by scientists worldwide does imply that the earth does have ecosystems that are actually fragile that they may tip at any time. Therefore, I agree with the paradigm of a fragile ecosystem.
However, as the paradigm is complex, I would like to conclude my letter by agreeing with D. A. Radcliffe (1976), who quoted, “the magic of the natural world beckons and challenges, and lures the receptive soul ever onwards but, like the Holy Grail, it is never finally found and possessed. And this is its fascination.”
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