Why are the human activities destroy the cycles in ecosystem?

Here are some disruptions:
=deforestation
=intensive fishing
=intensive farming
 

Deforestation.  See, when we cut down trees, the gas we use on saws and whatnot comes out as carbon dioxide.  This then floats up to our atmosphere, becoming a greenhouse gas.  Greenhouse gases keep the sun's thermal heat that hits us from escaping.  When it becomes another layer in the atmosphere, it traps more and more heat, causing global warming.  Although it would take years for this heat to cause major damage, man is inching closer to worldwide disaster with each tree cut down.  I hope this helps you understand.

Cutting down of trees, improperly disposing of garbage and factory sewage down sewage pipes or into the sea directly

Pollution, over building and more so on the shorelines of coastal cities and towns and other water front properties. Plus the taking animals and insects to other places to solve a problem in one area but then caused and other one else where causing an off balance.

Building a dam on a river would be an example. This is an activity of man that can have major implications for the ecosystem as many of the natural and native species can become extinct. If you were to read about the Colorado River and the many dams that have be constructed on it and how it has changed the natural process and habituate for native species that live or lived in the area. Today man attempts to recreate events along this river to recreate the natural events such as floods as some of the wildlife had been affected to the point that they stopped reproducing and the lack of silt from the natural events changed the habitat itself.

pollution , hardly cleaning the roads , chopping down trees , fishing etc

Discarding garbage, human waste, tires, etc into streams.

For example, the oxygen-carbon dioxide cycle. The human activities that affect this kind of cycle is like deforestation or cutting of trees, dynamite fishing and etc. This illegal human activities are supposedly the most fatal cause of the destruction of our NATURE. REMEMBER THIS: Nature can live without humans, but humans can't live without nature.. :))

Industrial, agricultural and construction can Disrupt The Ecosystem,they will polluted the Environment.

I would say that everything that man does to interfere with the way nature runs is disruptive to the eco system. There is not much man hasn't done to destroy the way things were. Much of the life on this planet is hanging by a very thin thread because man will not acknowledge his own terrible wrong doings. A lot will blame animals for this rather than stand up and take the rap themselves. I saw a doco where they were blaming the Elephants for the lack of food because they were eating and pushing down trees, yet before man came along, nature was well balanced and doing just fine. There are a lot of little thing like I just mentioned. Man has to take a stand and turn things around before it is too late. Man is the imbalance in this eco system.

The potential impact of human disturbance on wintering waterbirds using intertidal mudflats was considered by relating their numbers to the presence of nearby footpaths, roads, railroads, and towns. Data were obtained for six English estuaries from the Wetland Bird Survey Low Tide Count scheme. Counts were undertaken monthly from November to February, and data were available for an average of 2.8 years per estuary for the period 1992-1993 to 1999-2000. Count sections and the positions of man-made landscape features were mapped using a GIS. Generalized linear models tested whether bird numbers varied according to the estuary, month, area, whether or not the section bordered water, and the proportion of each section within a specified distance of each landscape feature. In addition, the proximity of sections to the nearest footpath access point was considered. Numbers of six of nine species, northern shelduck (Tadorna tadorna), red knot (Calidris canutus), dunlin (Calidris alpina), black-tailed godwit (Limosa limosa), Eurasian curlew (Numenius arquata) and common redshank (Tringa totanus), were significantly lower where a footpath was close to a count section, while those of brant (Branta bernicla) were greater. Northern shelduck, black-bellied plover (Pluvialis squatarola), dunlin, and black-tailed godwit numbers were reduced close to railroads and those of common ringed plover (Charadrius hiaticula), black-bellied plover, and Eurasian curlew close to roads. Common ringed plover numbers were greater close to towns. The relative distances to which species were affected by footpaths corresponded to published information concerning their flight distances in response to human disturbance. The study provided evidence that sustained disturbance associated with footpaths, roads, and railroads reduced local habitat quality for waterbirds and the carrying capacity of estuaries.

Because human destroy the world environment by their daily activities.

Fishing , Farming , Hunting