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Cycling of mineral nutrients in agricultural ecosystems
91
Australia. This a m o u n t of space is more than that given to the heathlands of Europe (44 pages), S. America (21 pages) and all of N. America (44 pages): in fact, outside Australian heaths, only Chapter 2 on S. African fynbos vegetation exceeds 50 pages and that is swollen by a 20-page appendix giving species lists of 10 sites. This imbalance is exacerbated by the generous use of space in such appendices, typified by 4 ~ o l u m n tables covering an entire page (pp. 162--3, pp. 201--6) in which each column contains only a single letter (e.g., r, f, o, etc). Species are repetitively listed by families and leaf size data given again and again (except pp. 203--6 where they are mysteriously omitted). Such careless use of space, although it produces a clearly laid out and easily followed format, adds to the cost of the book. The production is immaculate -- I noted only four minor typographical errors -- and the t w o ~ o l u m n format particularly pleasing. The figures and photographs are generally very good although I found I became irritated by some of the less clear general pictures with long lists of (to me) unfamiliar plant names with no way of knowing what was what (e.g., Figs. 4.9, 13.4). The expensive format, high-quality paper, generous use of space, lack of discipline in summarising information, and editorial freedom for each contributor are all features which suggest that the book, and the series, is aimed principally at libraries and reference collections. Its target is ecologists, biogeographers, and environmentalists generally and is likely to be particularly those concerned with land use, conservation and resource management (although individual volumes will be of interest to specialists in that particular ecosystem). I notice that, since Volume 1, the series has accreted an extra volume (30 are now planned) making, at a conservative estimate, the cost of the complete series likely to be around £1,000. The fact that individual purchasers may be precluded is finally confirmed by the discovery that the final page of Chapter 23 is exactly that -- the final page! For any sort of index you will have to buy Volume 9B (the interesting-looking contents of which are tantalisingly listed in this Volume). A.J. GRAY (Wareham, GreatBritain)
MINERAL NUTRIENT CYCLING
Cycling of Mineral Nutrients In Agricultural Ecosystems. M.J. Frissel (Editor). Developments in Agricultural and Managed-Forest Ecology, vol. 3. Elsevier Scientific Publishing Company, Amsterdam, 1978. vii + 356 pp., US $ 39.75/Dfi. 95.00, ISBN 0-444-41660-9. This volume is the outcome of the "First International Environmental Symposium" held in Amsterdam in 1976. An interdisciplinary group of
92 specialists present their views on the cycling of mineral nutrients in agroecosystems assuming that the understanding of these systems is essential to future work in land development. Increasing world population on the one hand and increasing destabilisation of agro-ecosystems on the other hand require a more efficient use of resources with less damaging environmental effects. "An important part of this technology is the use of fertilizers to provide nitrogen, phosphorus and potassium", which require much fossil energy (nitrogen) or have to be mined (phosphorus and potassium). The scarcity of these resources and the polluting effects of excess fertilization emphasize the need for quantifying the movement of nutrients "from softs to plants to animals and back to the softs again, throughout the world". Chapters 2 and 3 give a brief overview of the transfers of minerals, the principles of nutrient cycles, the mechanisms which control the movement of elements in systems and subsystems. "The amounts of nutrients transferred between the pools of agro-ecosystems are influenced not only by conditions and processes within the system, but also by circumstances and controlling forces outside the system" (e.g., climatic and atmospheric conditions). A general discussion is also given in Chapter 3 of those processes which mediate the mechanisms controlling conversion and transport of mineral nutrient elements, such as transport in the water phase, retention of nutrients by biomass, long-term effects of agriculture, manipulation of system controls. In Chapter 4, farm systems typical of various ecosystems are described and classified. In total, 65 agro-ecosystems are described with agricultural production systems such as food gathering, extensive livestock farming, shifting cultivation, extensive arable farming, mixed farming or self-sustaining unit systems, intensive agriculture and forests. Chapter 5 shows the method of data presentation, which has been modified as a result of discussions during the symposium (annex 1). The model for nutrient cycling in agro-ecosystems used here consists of three main compartments (pools): plant, livestock and soft. The soil pool is presented as a single pool, a fact which has been criticized and taken into account in the discussion. The boundaries within the model are rather simplified, which was necessary to make possible comparisons between the systems. It is mentioned by the editor, that not all authors followed the form suggested nor did all indicate the reliability or source of their data, so that Chapter 6 is suffering from "missing links". Chapter 6 describes nutrient cycling data in agro-ecosystems of various countries (European countries, Israel, Japan, Australia, U.S.A., South America). The spatial distribution seems slightly unbalanced: on the one hand, great emphasis is given to European countries and Israel, on the other hand extensive areas like Australia and South America are treated rather briefly. Chapter 7 contains the general discussion, demonstrating in an introductory table the qualitative indication of the state of balance of N, P and K
9 3
(relation of consumable output, losses to the atmosphere and leaching losses to the farm inputs), and the variance between the systems and minerals. The three mineral balances are discussed briefly. Also included is the abovementioned suggestion of dividing the soil pool into organic, mineral and available soil pools, Furthermore, a special view of the exchange of nutrients between atmosphere and vegetation--soil is presented. Considerations dealing with the possibilitiesof manipulating the systems and an outlook to the research needed in the future conclude this chapter. As mentioned in the summary, the volume gives an idea of the importance of this problem to world agriculture and to the maintenance of the quality of the environment and landscape. "It is concluded that no new information has emerged to alter entrenchedviews on the relative importance of future work on N, P and K; of sensitive systems where leaching losses and pollution might occur; and of the efficiency of fertilizeruse". As a result of the symposium it can be stated that the discussion of the data in a unified scheme has clearly identified areas with littleor very imprecise data and has indicated those areas urgently requiring further research; -- nutrient losses to the environment due to high farm inputs exist for all types of systems and are often proportional to the farm input. Because high farm inputs can almost only be realized by high fertilizerdressings, losses to the environment are often proportional to the fertilizeruse; despite the imperfection of data there is sufficient homogeneity in the balances obtained over a wide variety of ecosystems; more refined simulation models are desirable. At a time of increasing scarcity of resources the symposium is a remarkable approach to d¢sign more efficient ways of fertilizeruse in various production systems and different regions of the world. --
--
--
HARTMUT GAESE
(Heidelberg, Federal Republic of Germany)
BIOMONITORING AIR POLLUTANTS WITH PLANTS
Biomonitoring Air Pollutants with Plants. W.J. Manning and W.A. Feder, 142 pp. Applied Science Publishers, Barking, Essex, 1980. £12.00, ISBN 0-85334-916-9. TO quote the authors this b o o k was written to answer two questions -(a) which air pollutants affect plant ecosystems, and (b) where do they come from? While the reader will have gained many of the answers to the second, the first question remains largely unanswered. To some extent this deficiency reflects a lack of quantitative data. The reader is told that
Australia. This a m o u n t of space is more than that given to the heathlands of Europe (44 pages), S. America (21 pages) and all of N. America (44 pages): in fact, outside Australian heaths, only Chapter 2 on S. African fynbos vegetation exceeds 50 pages and that is swollen by a 20-page appendix giving species lists of 10 sites. This imbalance is exacerbated by the generous use of space in such appendices, typified by 4 ~ o l u m n tables covering an entire page (pp. 162--3, pp. 201--6) in which each column contains only a single letter (e.g., r, f, o, etc). Species are repetitively listed by families and leaf size data given again and again (except pp. 203--6 where they are mysteriously omitted). Such careless use of space, although it produces a clearly laid out and easily followed format, adds to the cost of the book. The production is immaculate -- I noted only four minor typographical errors -- and the t w o ~ o l u m n format particularly pleasing. The figures and photographs are generally very good although I found I became irritated by some of the less clear general pictures with long lists of (to me) unfamiliar plant names with no way of knowing what was what (e.g., Figs. 4.9, 13.4). The expensive format, high-quality paper, generous use of space, lack of discipline in summarising information, and editorial freedom for each contributor are all features which suggest that the book, and the series, is aimed principally at libraries and reference collections. Its target is ecologists, biogeographers, and environmentalists generally and is likely to be particularly those concerned with land use, conservation and resource management (although individual volumes will be of interest to specialists in that particular ecosystem). I notice that, since Volume 1, the series has accreted an extra volume (30 are now planned) making, at a conservative estimate, the cost of the complete series likely to be around £1,000. The fact that individual purchasers may be precluded is finally confirmed by the discovery that the final page of Chapter 23 is exactly that -- the final page! For any sort of index you will have to buy Volume 9B (the interesting-looking contents of which are tantalisingly listed in this Volume). A.J. GRAY (Wareham, GreatBritain)
MINERAL NUTRIENT CYCLING
Cycling of Mineral Nutrients In Agricultural Ecosystems. M.J. Frissel (Editor). Developments in Agricultural and Managed-Forest Ecology, vol. 3. Elsevier Scientific Publishing Company, Amsterdam, 1978. vii + 356 pp., US $ 39.75/Dfi. 95.00, ISBN 0-444-41660-9. This volume is the outcome of the "First International Environmental Symposium" held in Amsterdam in 1976. An interdisciplinary group of
92 specialists present their views on the cycling of mineral nutrients in agroecosystems assuming that the understanding of these systems is essential to future work in land development. Increasing world population on the one hand and increasing destabilisation of agro-ecosystems on the other hand require a more efficient use of resources with less damaging environmental effects. "An important part of this technology is the use of fertilizers to provide nitrogen, phosphorus and potassium", which require much fossil energy (nitrogen) or have to be mined (phosphorus and potassium). The scarcity of these resources and the polluting effects of excess fertilization emphasize the need for quantifying the movement of nutrients "from softs to plants to animals and back to the softs again, throughout the world". Chapters 2 and 3 give a brief overview of the transfers of minerals, the principles of nutrient cycles, the mechanisms which control the movement of elements in systems and subsystems. "The amounts of nutrients transferred between the pools of agro-ecosystems are influenced not only by conditions and processes within the system, but also by circumstances and controlling forces outside the system" (e.g., climatic and atmospheric conditions). A general discussion is also given in Chapter 3 of those processes which mediate the mechanisms controlling conversion and transport of mineral nutrient elements, such as transport in the water phase, retention of nutrients by biomass, long-term effects of agriculture, manipulation of system controls. In Chapter 4, farm systems typical of various ecosystems are described and classified. In total, 65 agro-ecosystems are described with agricultural production systems such as food gathering, extensive livestock farming, shifting cultivation, extensive arable farming, mixed farming or self-sustaining unit systems, intensive agriculture and forests. Chapter 5 shows the method of data presentation, which has been modified as a result of discussions during the symposium (annex 1). The model for nutrient cycling in agro-ecosystems used here consists of three main compartments (pools): plant, livestock and soft. The soil pool is presented as a single pool, a fact which has been criticized and taken into account in the discussion. The boundaries within the model are rather simplified, which was necessary to make possible comparisons between the systems. It is mentioned by the editor, that not all authors followed the form suggested nor did all indicate the reliability or source of their data, so that Chapter 6 is suffering from "missing links". Chapter 6 describes nutrient cycling data in agro-ecosystems of various countries (European countries, Israel, Japan, Australia, U.S.A., South America). The spatial distribution seems slightly unbalanced: on the one hand, great emphasis is given to European countries and Israel, on the other hand extensive areas like Australia and South America are treated rather briefly. Chapter 7 contains the general discussion, demonstrating in an introductory table the qualitative indication of the state of balance of N, P and K
9 3
(relation of consumable output, losses to the atmosphere and leaching losses to the farm inputs), and the variance between the systems and minerals. The three mineral balances are discussed briefly. Also included is the abovementioned suggestion of dividing the soil pool into organic, mineral and available soil pools, Furthermore, a special view of the exchange of nutrients between atmosphere and vegetation--soil is presented. Considerations dealing with the possibilitiesof manipulating the systems and an outlook to the research needed in the future conclude this chapter. As mentioned in the summary, the volume gives an idea of the importance of this problem to world agriculture and to the maintenance of the quality of the environment and landscape. "It is concluded that no new information has emerged to alter entrenchedviews on the relative importance of future work on N, P and K; of sensitive systems where leaching losses and pollution might occur; and of the efficiency of fertilizeruse". As a result of the symposium it can be stated that the discussion of the data in a unified scheme has clearly identified areas with littleor very imprecise data and has indicated those areas urgently requiring further research; -- nutrient losses to the environment due to high farm inputs exist for all types of systems and are often proportional to the farm input. Because high farm inputs can almost only be realized by high fertilizerdressings, losses to the environment are often proportional to the fertilizeruse; despite the imperfection of data there is sufficient homogeneity in the balances obtained over a wide variety of ecosystems; more refined simulation models are desirable. At a time of increasing scarcity of resources the symposium is a remarkable approach to d¢sign more efficient ways of fertilizeruse in various production systems and different regions of the world. --
--
--
HARTMUT GAESE
(Heidelberg, Federal Republic of Germany)
BIOMONITORING AIR POLLUTANTS WITH PLANTS
Biomonitoring Air Pollutants with Plants. W.J. Manning and W.A. Feder, 142 pp. Applied Science Publishers, Barking, Essex, 1980. £12.00, ISBN 0-85334-916-9. TO quote the authors this b o o k was written to answer two questions -(a) which air pollutants affect plant ecosystems, and (b) where do they come from? While the reader will have gained many of the answers to the second, the first question remains largely unanswered. To some extent this deficiency reflects a lack of quantitative data. The reader is told that