Are some ecosystems really more "fragile" than others; and, if so, why?

Question

I often read or hear a particular environment, such as the arctic, described as "fragile". I guess a related question is, what does it mean for an ecosystem to be fragile?

Answer 1

Yes, some ecosystems are more fragile. "A fragile environment is an ecosystem or community which lacks resilience or which is so heavily impacted by an 'un-natural' (human?) event that it changes in unexpected and undesirable ways" (http://www.es.mq.edu.au/hsc/fra_eco1/lecoh.htm)
In fragile ecosystems small actions have large repercussions that in turn affect other ecosystems. For example, a change in 1 degree of temperature in the arctic has a effect on all ecosystems across the globe (tree-lines, animals and their migration habits, melting ice leading to raising sea levels, melting permafrost layers, etc).

Answer 2

Yes, some ecosystems are more fragile than others. Some ecosystems are fragile because of the type of plants and animals, as well as other organisms, that are living there. A fragile ecosystem is more sensitive to changes in the environment than other ecosystems. For example, their are some invertebrates that live in a stream or river that are more tolerant of pollutants than other invertebrates that live in the same stream. If the invertebrates that are the most tolerant of pollutants are not present in the stream or river then you know that there is a really big problem.

Answer 3

Often times an ecosystem is considered more fragile because of the number of species that live there. The more species in an area, like rain forests, the more they dpend on eachother. This means that of one animal is hurt by a certain pesticide, then all the other species are hurt to, because that animal did something in the ecosystem that another animal needed, so then another animal is hurt, and so on

Some ecosystems are just naturally fragile like a lake. If the water is polluted, the lake suffers. It's not hard to pollute a lake.

Answer 4

The arctic has become a fragile ecosystem because it will not take much more to completely destroy it, while many ecosystems are more robust and can absorb greater levels of pollutants and or heat change before becoming fragile.

Answer 5

I have mostly heard the term used in regards to an environment that requires special protection from humans.

For instance, in the alpine gardens above tree line in the New Hampshire White Mountains, the plants can withstand just about any kind of horrible weather condition you can imagine, but they cannot handle being trodden on by human boots, so it is considered a 'fragile' environment.