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Air pollution and forests: Interactions between air contaminants and forest ecosystems
298
from which practitioners may select a procedure; but the reader is left to choose a method suitable to the task. As in all areas of science, sound and enduring progress has been made where hypotheses (models) can be proved empirically, such as in the analyses of the 'hot spot', which is treated in the book in several places. The scope of the book was confined mainly to theoretical analyses of radiation, with relatively little emphasis on empirical verification, however, enduring scientific worth is predicated by such verification. In as far as the predictions are unmeasured, assessment of scientific worth is deferred, perhaps, for ever. Chapter 15 by P. Oker-Blom, J. Lappi and H. Smolander provides a link between the radiation climate in an array of trees assumed to consist of assemblies of shoots, with the photosynthesis of the canopy. This theme is explored further in Chapter 16 where specifications are given for radiation and photosynthetic variables so that their combination is compatible for estimating gross photosynthesis. The chapters are well written and edited. As must be expected, the consistency and cohesion of style and symbolism is less than that attainable by one author, and the book is probably 50% longer as a consequence of the multiplicity of contributors. The book will serve as a reference, as has its predecessor, for scientists studying the interaction of radiation with vegetation and the resultant radiation fields, photosynthesis and energy balance of vegetation (although this last important subject is given only passing reference in the book). I recommend it to scholars of radiation in vegetation. A.R.G. L A N G CSIRO Centre for Environmental Mechanics Canberra 2601 Australia
REFERENCE Ross, J., 1981. The Radiation Regime and Architecture of Plant Stands. W. Junk, The Hague, Netherlands, 391 pp.
Air Pollution and Forests." Interactions between Air Contaminants and Forest Ecosystems.William H. Smith, 2nd edn., 1990, Springer, 618 pp. Hardcover D M 198.00, ISBN 3-540-97084-3. The aim of this book is to review the interactions of air and all the extraneous bodies in it, on the one hand, and forests on the other. People
299
generally think that what is named 'pollution' comes only from mans' activities. In reality, the forest itself causes a great deal of so named 'pollutants' to be emitted into the atmosphere. In many cases, the quantity resulting from the metabolism of trees is greater than the quantity produced by mans' activity. In the first part of this book, the author gives a review of those effects and makes a comparison between natural and manmade pollution in the air. Reading this well documented part, one may be shocked by the unilateral way we are informed, through newspaper, radio and TV, of the matter. As an example, it is always said that ozone is produced by the action of UV-radiation on nitrogen oxides alone, the latter originates from the combustion of hydrocarbons in motors. In reality, the effect of the reaction of the UV-radiation on terpenes issued from trees' metabolism, in particular from coniferous ones, is nearly the same in quantity. The forest also gives great quantities of sulfur dioxide to the atmosphere by the putrification of its litter and by forest fires (natural and manmade ones). But the vegetation is not alone in emitting such gases to the air, volcanic activity must also be taken into consideration. Considering the so-called atmospheric pollution, it is necessary to make a distinction between the natural one which is not to be managed by man and the manmade one. The latter should be reduced in all parts to reduce the impact on forest development. Nearly all the extraneous bodies in the air have a negative effect on vegetational metabolism. In the second part of his book, the author analyses the specific reactions of the trees to the different pollutants, natural as well as manmade. We have very little reliable information on those actions on reproduction (pollination and flowering). The uptake of minerals through the roots is dependent on the recycling velocity of the deposition of organic and inorganic materials. In that case, the heavy metals probably play an important role. The effects of filtration of forest soils are analysed in detail. In that case, 'acid rain' must be taken into consideration. The 'acidity' of falling water (rain and snow) is not only the result of mans' activities, such as smelting of metals for example, but also of the metabolism of the vegetation. Accumulation of dry materials affects, not only the soils of the forest, but also the foliage and has a specific action which can be very disastrous for the whole tree growth. From that point of view, pollution is changing the assimilation conditions and in that way the growth and the competition of the different species among themselves. Therefore, heavy pollution can change the composition of the vegetation in a given locality. The vitality of the trees is affected by the impact of gases and solid materials on the leaves as well as in the soil and in that way reduces the resistance of the trees to fungi and insects. The forest is, in natural conditions, the most productive ecosystem, but its equilibrium is unstable in most cases, so little changes in external living conditions have rapid and serious consequences on it. The requirement of forests is not only to produce wood but to
300
BOOK REVIEW
diminish the content of atmospheric carbon dioxide. The forests play a great role in the welfare of man, so it is a necessity for us all to conserve its vitality at a very high level. The third part of the book is devoted to the analysis of very strong air pollution in the proximity of heavy pollution sources; iron or aluminium smelting-houses for example. In such places, the pollution can be so strong that any vegetational existence is eliminated. The farther the source of pollutants the lesser the impact of pollution on the vegetation in general and the trees in particular. The first signal of too much pollution is the reduction of species. However, such a simplified system is not necessarily durable. It can rapidly be destroyed by an uninterrupted increase of a long duration of pollution. In the last part of his work, the author mentions the probable effect of atmospheric pollution on the climate, in particular on the temperature and the radiation (UV-B). These two atmospheric parameters have a great impact on the vitality of the forests as well as their predators (insects and fungi). If we want to conserve our forests in good condition, we must look to diminish manmade pollution in all its forms. We have no power to influence natural pollution. Finally, I would like to make some personal observations. In my mind the title of this book is wrong. It should be: "Air pollution and forests in North America". Nearly all the examples pointed out are from the United States or Canada and the rich bibliography gives very few examples of work done in Europe or Asia or written in a language other than English. In reality, there are many good works coming from these areas or published in German, French or Spanish. With exception of the fungi, we find no latin names of species. This is a serious handicap for people speaking any other language to recognise what tree is mentioned. I recommend attentive reading of this book. It contains a lot of useful information on pollutants, pollution sources, pollution concentrations as well as their impacts on forests' trees, insects, fungi and soil organisms. In many parts of this book it is mentioned that we do not know enough about the interactions of air pollutants and vegetation. It is absolutely necessary to move forward with research in this matter. B. P R I M A U L T Witkonerstrasse 440 CH-8053 Zurich Switzerland
from which practitioners may select a procedure; but the reader is left to choose a method suitable to the task. As in all areas of science, sound and enduring progress has been made where hypotheses (models) can be proved empirically, such as in the analyses of the 'hot spot', which is treated in the book in several places. The scope of the book was confined mainly to theoretical analyses of radiation, with relatively little emphasis on empirical verification, however, enduring scientific worth is predicated by such verification. In as far as the predictions are unmeasured, assessment of scientific worth is deferred, perhaps, for ever. Chapter 15 by P. Oker-Blom, J. Lappi and H. Smolander provides a link between the radiation climate in an array of trees assumed to consist of assemblies of shoots, with the photosynthesis of the canopy. This theme is explored further in Chapter 16 where specifications are given for radiation and photosynthetic variables so that their combination is compatible for estimating gross photosynthesis. The chapters are well written and edited. As must be expected, the consistency and cohesion of style and symbolism is less than that attainable by one author, and the book is probably 50% longer as a consequence of the multiplicity of contributors. The book will serve as a reference, as has its predecessor, for scientists studying the interaction of radiation with vegetation and the resultant radiation fields, photosynthesis and energy balance of vegetation (although this last important subject is given only passing reference in the book). I recommend it to scholars of radiation in vegetation. A.R.G. L A N G CSIRO Centre for Environmental Mechanics Canberra 2601 Australia
REFERENCE Ross, J., 1981. The Radiation Regime and Architecture of Plant Stands. W. Junk, The Hague, Netherlands, 391 pp.
Air Pollution and Forests." Interactions between Air Contaminants and Forest Ecosystems.William H. Smith, 2nd edn., 1990, Springer, 618 pp. Hardcover D M 198.00, ISBN 3-540-97084-3. The aim of this book is to review the interactions of air and all the extraneous bodies in it, on the one hand, and forests on the other. People
299
generally think that what is named 'pollution' comes only from mans' activities. In reality, the forest itself causes a great deal of so named 'pollutants' to be emitted into the atmosphere. In many cases, the quantity resulting from the metabolism of trees is greater than the quantity produced by mans' activity. In the first part of this book, the author gives a review of those effects and makes a comparison between natural and manmade pollution in the air. Reading this well documented part, one may be shocked by the unilateral way we are informed, through newspaper, radio and TV, of the matter. As an example, it is always said that ozone is produced by the action of UV-radiation on nitrogen oxides alone, the latter originates from the combustion of hydrocarbons in motors. In reality, the effect of the reaction of the UV-radiation on terpenes issued from trees' metabolism, in particular from coniferous ones, is nearly the same in quantity. The forest also gives great quantities of sulfur dioxide to the atmosphere by the putrification of its litter and by forest fires (natural and manmade ones). But the vegetation is not alone in emitting such gases to the air, volcanic activity must also be taken into consideration. Considering the so-called atmospheric pollution, it is necessary to make a distinction between the natural one which is not to be managed by man and the manmade one. The latter should be reduced in all parts to reduce the impact on forest development. Nearly all the extraneous bodies in the air have a negative effect on vegetational metabolism. In the second part of his book, the author analyses the specific reactions of the trees to the different pollutants, natural as well as manmade. We have very little reliable information on those actions on reproduction (pollination and flowering). The uptake of minerals through the roots is dependent on the recycling velocity of the deposition of organic and inorganic materials. In that case, the heavy metals probably play an important role. The effects of filtration of forest soils are analysed in detail. In that case, 'acid rain' must be taken into consideration. The 'acidity' of falling water (rain and snow) is not only the result of mans' activities, such as smelting of metals for example, but also of the metabolism of the vegetation. Accumulation of dry materials affects, not only the soils of the forest, but also the foliage and has a specific action which can be very disastrous for the whole tree growth. From that point of view, pollution is changing the assimilation conditions and in that way the growth and the competition of the different species among themselves. Therefore, heavy pollution can change the composition of the vegetation in a given locality. The vitality of the trees is affected by the impact of gases and solid materials on the leaves as well as in the soil and in that way reduces the resistance of the trees to fungi and insects. The forest is, in natural conditions, the most productive ecosystem, but its equilibrium is unstable in most cases, so little changes in external living conditions have rapid and serious consequences on it. The requirement of forests is not only to produce wood but to
300
BOOK REVIEW
diminish the content of atmospheric carbon dioxide. The forests play a great role in the welfare of man, so it is a necessity for us all to conserve its vitality at a very high level. The third part of the book is devoted to the analysis of very strong air pollution in the proximity of heavy pollution sources; iron or aluminium smelting-houses for example. In such places, the pollution can be so strong that any vegetational existence is eliminated. The farther the source of pollutants the lesser the impact of pollution on the vegetation in general and the trees in particular. The first signal of too much pollution is the reduction of species. However, such a simplified system is not necessarily durable. It can rapidly be destroyed by an uninterrupted increase of a long duration of pollution. In the last part of his work, the author mentions the probable effect of atmospheric pollution on the climate, in particular on the temperature and the radiation (UV-B). These two atmospheric parameters have a great impact on the vitality of the forests as well as their predators (insects and fungi). If we want to conserve our forests in good condition, we must look to diminish manmade pollution in all its forms. We have no power to influence natural pollution. Finally, I would like to make some personal observations. In my mind the title of this book is wrong. It should be: "Air pollution and forests in North America". Nearly all the examples pointed out are from the United States or Canada and the rich bibliography gives very few examples of work done in Europe or Asia or written in a language other than English. In reality, there are many good works coming from these areas or published in German, French or Spanish. With exception of the fungi, we find no latin names of species. This is a serious handicap for people speaking any other language to recognise what tree is mentioned. I recommend attentive reading of this book. It contains a lot of useful information on pollutants, pollution sources, pollution concentrations as well as their impacts on forests' trees, insects, fungi and soil organisms. In many parts of this book it is mentioned that we do not know enough about the interactions of air pollutants and vegetation. It is absolutely necessary to move forward with research in this matter. B. P R I M A U L T Witkonerstrasse 440 CH-8053 Zurich Switzerland