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Structure and function of Northern Coniferous Forests — An ecosystem study
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Structure and Function of Northern Coniferous Forests - - A n Ecosystem Study. T. Persson (Editor). Ecological Studies, No. 32, Swedish Natural Science Research Council ( N FR ) , St ockhol m , 1980, 609 pp., SwK. 290.00 (incl. air mail postage). The b o o k is th e first comprehensive d o c u m e n a t i o n of t he studies included within th e Swedish Coniferous Project. It contains 37 single papers, all of t h e m dealing with aspects o f t he structure and t he functional processes of Scots pine (Pinus sylvestris L.) forests which cover m ore than 40% of the whole c o u n t r y . The project, started in 1972 with field studies, was c o n d u c t e d in Central Sweden in a 160-years-old mixed mature stand of pine and spruce and on 6 sites with stands o f pines of different age, height and density (age species up to an 120 year old stand incl. clear fellings of pine). This interdisciplinary ecosystem research project can be seen as the second generation o f such projects following those o f the International Biological Programme o f 1 9 6 4 - - 1 9 7 4 . The results of t he field studies are t he basis for m a n y math ematic models which describe t he structure and processes of the stands, o f single trees but also of organs such as needles, roots etc. T h e y also describe th e processes in t he atmosphere inside and above the stands, as well as t h e soil processes. T h e y t h e r e f o r e give a basis for predictions. After an i n t r o d u c t o r y description o f the project, o f the features of the investigation sites and o f t he handling o f data and of the simulation used technique, mostly original papers on t he results o f field studies are presented, but some review papers are also included. The b o o k is divided in two main groups o f papers: The forest ecosystem with t he different processes and the theoretical approaches t o forest functioning. The first main chapter with the abiotic processes, i.e. t he results o f t he field studies on local climate, micrometeorological conditions inside and above t he stands and within the soil layers. The hydrological aspects including evapotranspiration of the stands, are described as well as all i m p o r t a n t energy exchanges. Sixteen papers on plant and vegetation processes represent t he central part o f the whole project and hence o f t he book. T h e y deal with the growth of t h e stand, the single trees as well as organs such as needles, roots and shoots. The studies were made unde r natural conditions, but also with use o f fertilizers and irrigation, so t ha t water and nutrients were not limiting factors. To understand the primary net p r o d u c t i o n , all physiological processes, e.g. photosynthesis, respiration and transpiration are included. Detailed analyses of tree and stand growth and on t he annual carbon budget are given as well as o f field studies on insect c o n s u m p t i o n and on t he mutual relationships bet w e en needle-eating insects and Scots pine. The high p r o d u c t i o n o f fine r oot s n o t e d -- m ore than 50% of t he assimilates f o r m e d was used for growth and maintenance of t he r o o t system -also indicates u n e x p e c t e d results. The possibility o f generalizing the results and hence o f extrapolating results f r om one site to a whole region is also shown. The studies were made and t he results d e m o n s t r a t e d with different
354 time scales, from the gaseous exchange (hours) to the long-term growth of the stands (years). All these studies on plant processes give the basis for the later described mathematical models. Within the next subchapter, 9 papers are devoted to different soil processes, especially within the mature pine stand. Initially the problems started with single topics: the leaching of carbon, nitrogen, phosphorus and potassium in litter humus and mineral layers, the decomposition of different types o f substrates under given climatological conditions, the mineralization of CNP from substrates, input and o u t p u t of easily available nitrogen, the influence o f soil organisms on the decomposition and mineralization, etc. Finally interest is focused on synthesic work which is found in the last main chapter devoted to the theoretical approach and in which the processes like the seasonal dynamics of different soil processes, the influx of nutrients through precipitation, nitrogen fixation and nutrient transport are described b y models, as well as the biomass dynamics of the soil animal populations and their relation to carbon retention and release. The models also deal with the climatic influence o n carbon and nitrogen transformation in the soils, with emphasis on the balance between nitrogen leaching and uptake b y plant roots. The last chapter presents also other simulation models from the microclimatological and hydrological conditons in the stands, including the different energy exchanges and gaseous transport in tree growth. This documentation is a substantial contribution toward a better understanding of plant growth within stands -- which can be found so widely distributed -- and their regulation b y ecological factors. The documentation is well balanced in the different chapters, which are very well coordinated. The project represents an excample of h o w ecosystem studies have to be made in the future: starting with many coordinated field studies o f the governing abiotic factors, of the reactions o f the plants and vegetation and summarizing and synthesising b y mathematic modeling. Without such modeling, many unsolved and open problems cannot be seen. A better understanding of the dynamics of the plant-biomass process is obtained in this way. Finally, the p r o o f is demonstrated that such studies are necessary also to understand human impacts on ecological systems and their consequences, e.g. b y the aciditation of precipitation. This b o o k will be a valuable tool for everyone w h o is starting ecological investigationgs of stands and vegetation covers -also in other climates and with other t y p e s of vegetation. J. V A N E I M E R N (GSttingen)
Structure and Function of Northern Coniferous Forests - - A n Ecosystem Study. T. Persson (Editor). Ecological Studies, No. 32, Swedish Natural Science Research Council ( N FR ) , St ockhol m , 1980, 609 pp., SwK. 290.00 (incl. air mail postage). The b o o k is th e first comprehensive d o c u m e n a t i o n of t he studies included within th e Swedish Coniferous Project. It contains 37 single papers, all of t h e m dealing with aspects o f t he structure and t he functional processes of Scots pine (Pinus sylvestris L.) forests which cover m ore than 40% of the whole c o u n t r y . The project, started in 1972 with field studies, was c o n d u c t e d in Central Sweden in a 160-years-old mixed mature stand of pine and spruce and on 6 sites with stands o f pines of different age, height and density (age species up to an 120 year old stand incl. clear fellings of pine). This interdisciplinary ecosystem research project can be seen as the second generation o f such projects following those o f the International Biological Programme o f 1 9 6 4 - - 1 9 7 4 . The results of t he field studies are t he basis for m a n y math ematic models which describe t he structure and processes of the stands, o f single trees but also of organs such as needles, roots etc. T h e y also describe th e processes in t he atmosphere inside and above the stands, as well as t h e soil processes. T h e y t h e r e f o r e give a basis for predictions. After an i n t r o d u c t o r y description o f the project, o f the features of the investigation sites and o f t he handling o f data and of the simulation used technique, mostly original papers on t he results o f field studies are presented, but some review papers are also included. The b o o k is divided in two main groups o f papers: The forest ecosystem with t he different processes and the theoretical approaches t o forest functioning. The first main chapter with the abiotic processes, i.e. t he results o f t he field studies on local climate, micrometeorological conditions inside and above t he stands and within the soil layers. The hydrological aspects including evapotranspiration of the stands, are described as well as all i m p o r t a n t energy exchanges. Sixteen papers on plant and vegetation processes represent t he central part o f the whole project and hence o f t he book. T h e y deal with the growth of t h e stand, the single trees as well as organs such as needles, roots and shoots. The studies were made unde r natural conditions, but also with use o f fertilizers and irrigation, so t ha t water and nutrients were not limiting factors. To understand the primary net p r o d u c t i o n , all physiological processes, e.g. photosynthesis, respiration and transpiration are included. Detailed analyses of tree and stand growth and on t he annual carbon budget are given as well as o f field studies on insect c o n s u m p t i o n and on t he mutual relationships bet w e en needle-eating insects and Scots pine. The high p r o d u c t i o n o f fine r oot s n o t e d -- m ore than 50% of t he assimilates f o r m e d was used for growth and maintenance of t he r o o t system -also indicates u n e x p e c t e d results. The possibility o f generalizing the results and hence o f extrapolating results f r om one site to a whole region is also shown. The studies were made and t he results d e m o n s t r a t e d with different
354 time scales, from the gaseous exchange (hours) to the long-term growth of the stands (years). All these studies on plant processes give the basis for the later described mathematical models. Within the next subchapter, 9 papers are devoted to different soil processes, especially within the mature pine stand. Initially the problems started with single topics: the leaching of carbon, nitrogen, phosphorus and potassium in litter humus and mineral layers, the decomposition of different types o f substrates under given climatological conditions, the mineralization of CNP from substrates, input and o u t p u t of easily available nitrogen, the influence o f soil organisms on the decomposition and mineralization, etc. Finally interest is focused on synthesic work which is found in the last main chapter devoted to the theoretical approach and in which the processes like the seasonal dynamics of different soil processes, the influx of nutrients through precipitation, nitrogen fixation and nutrient transport are described b y models, as well as the biomass dynamics of the soil animal populations and their relation to carbon retention and release. The models also deal with the climatic influence o n carbon and nitrogen transformation in the soils, with emphasis on the balance between nitrogen leaching and uptake b y plant roots. The last chapter presents also other simulation models from the microclimatological and hydrological conditons in the stands, including the different energy exchanges and gaseous transport in tree growth. This documentation is a substantial contribution toward a better understanding of plant growth within stands -- which can be found so widely distributed -- and their regulation b y ecological factors. The documentation is well balanced in the different chapters, which are very well coordinated. The project represents an excample of h o w ecosystem studies have to be made in the future: starting with many coordinated field studies o f the governing abiotic factors, of the reactions o f the plants and vegetation and summarizing and synthesising b y mathematic modeling. Without such modeling, many unsolved and open problems cannot be seen. A better understanding of the dynamics of the plant-biomass process is obtained in this way. Finally, the p r o o f is demonstrated that such studies are necessary also to understand human impacts on ecological systems and their consequences, e.g. b y the aciditation of precipitation. This b o o k will be a valuable tool for everyone w h o is starting ecological investigationgs of stands and vegetation covers -also in other climates and with other t y p e s of vegetation. J. V A N E I M E R N (GSttingen)