by rpavlis2 on Sun Jul 15, 2007 7:41 pm
There are a quite a few species of plants that are toxic, some dangerously so. One of the most amazingly toxic of common plants is oleander.
There are also a LOT of toxic compounds that people spray on plants to prevent their being eaten by hungry insects. Some of these compounds can stay around a long time and are also toxic to birds and other organisms as well as insects. Others are certainly toxic only to insects. There are far fewer really nasty things being used today than in the past, but one must realise that human toxicity is considered far more than avian when pesticides are approved for use on various things.
When trees have been fertiilised with standard inorganic fertilisers like phosphates, ammonium salts, potassium nitrate, etc. they are receiving the same ions that they normally get from healthy soil but that humans typically have, from using very bad conservation practices, depleted from the soil. This does not produce a toxicity hazard for now. However, the practices that make it necessary to do this are creating horrible ecological damage to the entire planet. There ARE a few organic (carbon containing) compounds, not inorganic ones, that may well create hazards. Under natural conditions plants absorb virtually only inorganic ions from their roots, typically phosphate, sodium, nitrate, and sulphate, as well as dozens of ions required in small quantities, some in truly trace quantities, in fact. Even carnivorous plants do not absorb organic compounds from their "prey". Their prey decomposes, and generates inorganic ions that the plant absorbs.
It always seems odd to me as a scientist that fertilisers are so often thought of as creating a serious hazard when the reality is that they are used because soil depletion occurred because of horrible agricultural practices of the past. In reality they are being used to compensate for other foolishness done by mankind which has become necessary to keep much of the planet from being a wasteland.
Humans treat their agricultural land like a potassium and phosphorous mines. They grow crops on them, and harvest them taking away nutrients all the time. These nutrients then end up in sewage where they typically are typically placed in situations where they will not be recycled for thousands of years. It is standard practice in many places for people to cut their lawn grass and carry away all the clippings which ultimately remove all of the essential nutrients from the soil.
Not only are many of the world's species, especially birds, threatened by human agricultural practices, future generations of humans are threatened as well. We are in the process of turning much of the planet into a wasteland. (A lot of it already is that way!)
Be very sure you are not using a toxic plant--this is usually the most serious hazard!!! But also worry a lot about pesticides. Some familiar plants are fairly toxic.
There are also serious hazards from pests.
Robert Pavlis