Martin Kent - Academia.edu (original) (raw)

Papers by Martin Kent

Practical Ecology for Geography and Biology, 1985

Detailed surveys of vegetation often require data on species composition in addition to, or inste... more Detailed surveys of vegetation often require data on species composition in addition to, or instead of, structural or physiognomic descriptions. Such studies involve the identification of individual species and also the assessment of abundance of species. The techniques applied are known as floristic methods of vegetation description. The collection of data at the species level is fundamental to biogeography and ecology. Individual plant species are the building blocks of plant communities (see Section 2.3) and satisfactory survey and explanation of the distribution of communities as well as individual species requires floristic description. Also detailed appreciation of plant-environmental relationships and the effects of management of vegetation by man can often only be fully understood by a floristic survey.

Practical Ecology for Geography and Biology, 1985

Environmental pollution is now receiving a great deal of attention. It is of increasing concern n... more Environmental pollution is now receiving a great deal of attention. It is of increasing concern not just to biologists and ecologists, but also to many other professions including economists, planners, geographers and politicians. Pollution is a consequence of attitudes of mind, overpopulation and technological developments. Pollution is not a new problem, neither is it one which can be ignored. The nature and effects of pollution are variable, often being insidious rather than dramatic. Frequently people adopt, or are encouraged to adopt, a complacent or ‘optimistic ‘attitude to the problem. It is argued that pollution is a necessary and acceptable consequence of an important industrial or agricultural process, or that it is essential to the maintenance of employment. A common, but debatable assumption, is that in ‘good time’ the appropriate techniques will be developed to reduce or eliminate the problem.

The Geographical Journal, 1999

Practical Ecology for Geography and Biology, 1985

There is a natural curiosity to know what happens to the distribution of plants and animals outsi... more There is a natural curiosity to know what happens to the distribution of plants and animals outside the area which is well known to you. When it is necessary to establish the distribution of a particular taxon or community over hundreds or thousands of square kilometres, special procedures must be adopted. For example, many people are likely to become involved in the project and there may be problems of language or difficulties in communication. In addition, at these spatial scales the character of the ground mapping unit, within which individual surveys are being conducted, becomes extremely important.

Practical Ecology for Geography and Biology, 1985

This book is an introduction to four important aspects of ecology, environmental biology and biog... more This book is an introduction to four important aspects of ecology, environmental biology and biogeography: 1 to sources of information; 2 to methods of data collection; 3 to techniques of survey and mapping; 4 to the analysis and interpretation of biological and environmental data using simple statistical methods.

Practical Ecology for Geography and Biology, 1985

Vegetation and ecosystems are dynamic in nature. Plants form the food source for all other organi... more Vegetation and ecosystems are dynamic in nature. Plants form the food source for all other organisms and all food webs are ultimately dependent on the amount of plant tissue or biomass available for consumption. The rate of growth of plants varies greatly in response to the whole range of environmental limitations, but most notably climatic factors of solar radiation and moisture. Changes in growth rate are affected seasonally and also by the stage in the life cycle of a particular plant species. The amount of plant tissue which is accumulated in a given area over a certain period of time is known as the primary production or productivity. An important related concept is that of biomass or standing crop, which is the amount of plant tissue in a given area at one point in time. Most methods for measuring primary production are based on the repetition of biomass measurements at several points in time, with any increase in biomass representing the net primary production.

This paper presents a novel approach for the identification of suitable wetland restoration sites... more This paper presents a novel approach for the identification of suitable wetland restoration sites at a regional scale, using readily available soil and topographic data. The study focuses on Rhos pasture, a floristically diverse wet grassland community, which has been under threat from agricultural improvement in the past and more recently from neglect. The HOST classification was used to describe soil hydrological properties and topography was expressed using the ln(a/tanβ) topographic index. Distributions of soil hydrology and the topographic index under Rhos pasture sites were compared to the distributions of the total area and significance of the differences was assessed with chi-squared tests. Results were integrated into a decision support system, which predicted 72% of the existing sites. The method provides a useful tool for restoration planning at the decision-making scale.

Relationships between the distribution of animals and vegetation exist first because plants provi... more Relationships between the distribution of animals and vegetation exist first because plants provide the food source for many animals and represent the base of the trophic pyramid (see Section 2.2); and second because plants and vegetation act as a habitat within which many organisms live, grow and reproduce. For these reasons, relationships may be found between particular animal and plant species or vegetation types and this forms the justification for habitat survey methods (see Section 7.10). This type of association can be investigated and analysed very simply using the chi-squared (χ2) test. This test is often incorrectly termed the chi-square test.

Practical Ecology for Geography and Biology

The discussion of limiting factors in Section 2.4 showed that the distribution of both plant and ... more The discussion of limiting factors in Section 2.4 showed that the distribution of both plant and animal species and communities may be controlled by one or more environmental factors such as frequency of severe frost, available soil moisture, soil nutrient status, pollution, or by biotic pressures such as trampling or grazing. Although several factors may interact to control the distribution of a species, ultimately the nature of one factor, (the master limiting factor), will become critical and that species will no longer be able to survive.

Solute concentrations in throughfall, stem- flow, litterflow, soil water and springs were monitor... more Solute concentrations in throughfall, stem- flow, litterflow, soil water and springs were monitored in a sitka spruce (Picea sitchensis) forest and in a non- forested area. Analyses of stream water upstream and downstream of the afforested area revealed increased solute concentrations resulting from enhanced entrapment of atmospheric salts by the trees and increased weather- ing arising from the production of organic acids and chelates from decaying spruce needles. No significant difference in acidification upstream and downstream of the forest was observed. It was concluded that release of nutrients from litter decomposition balances nutrient uptake and the release of base cations by weathering buffers the system.

Global Ecology and Biogeography Letters

Progress in Physical Geography: Earth and Environment, 1997

The increasing relevance and importance of the subject of landscape ecology to bio geography are ... more The increasing relevance and importance of the subject of landscape ecology to bio geography are introduced. Research into landscape and plant community boundaries, never theless, remains comparatively neglected. In particular, the nature of those boundaries in terms of the patterns of floristic change and related ecosystem properties constitutes a potentially signifi cant new area of research for biogeographers. The term 'ecotone' has traditionally been used to describe boundaries between plant communities and ecosystems at a range of scales. Various definitions are presented and the often confusing terminology surrounding the word 'ecotone' is reviewed. Boundary types range from sharp, clearly defined boundaries (ecotones) between more highly modified plant communities and anthropogenically created land-use types at one extreme, to more gradual and diffuse boundaries (ecoclines) between natural and semi-natural plant communities at the other. It is proposed that th...

Progress in Physical Geography: Earth and Environment, 2000

and sedimentation. The latter study, developing on earlier work by Veldkamp, looks at the use of ... more and sedimentation. The latter study, developing on earlier work by Veldkamp, looks at the use of simple models to elucidate the relative significance of different processes in the formation of fluvial terraces, and is a useful illustration of the use of numerical models in the testing of hypotheses, development of theories and the indication of the focus of future field studies. The second section – ‘Palaeohydrological interpretations from depositional sequences and geomorphological changes’ – contains two case studies from The Netherlands, one from Siberia and one from Belarus. These studies focus on the Last Glacial period. Similarly, the third section, entitled ‘Palaeohydrology and environmental changes’, includes four case studies from Japan, Crete, Germany and Spain. ‘Late Pleistocene palaeohydrology’ has a distinctly Russian flavour. Two chapters consider the large-scale patterns and hydrological events of the Last Glacial period. In particular, the evidence for catastrophic outburst floods of the Glacial Lake Missoula type is presented, and suggests that this type of phenomenon occurred in a number of places throughout Eurasia. Although some of this evidence has been presented in English before, these chapters provide useful summaries of work to date. The third chapter is a modelling study of changes in the level of the Caspian Sea. Again the latter is a useful attempt, if only to point out the data limitations in trying to make such a reconstruction. The section on ‘Tropical zone palaeohydrology’ contains examples from both Africa and the Amazon Basin, mainly from a geomorphogical perspective. Finally, the four chapters in ‘Response of extreme events to climatic change’ consider examples from Poland, Syria and Spain. These studies tend to consider much shorter time periods than the other chapters in the book. However, given the significance of extreme events in the environments discussed, the chapters provide some useful indications of how research in this important area might progress. As with any volume of conference papers, one has to consider whether the whole is better than the sum of the parts. This book tends to lack coherence, but does have a number of useful themes running through it to make up for this problem. The focus on extreme and catastrophic events is one of these, of wider interest than hydrological investigations, with significant implications for the study of geomorphology and ecology as well as other disciplines. There is an increasing awareness of the need to link empirical data with observations from other sources, notably simulation models. Only by the iterative process successfully demonstrated in some of the chapters can the discipline of palaeohydrology as a whole hope to succeed. Perhaps further theoretical contributions along the lines of Baker’s would also be useful in pushing forward the subject. The complaints with the chapters are relatively few. There is still a tendency to use uncalibrated radiocarbon dates, despite the fact that calibrations are now available into and beyond the Last Glacial Maximum (in fact only one chapter uses the correct format). Apart from being incorrect such useage can make comparisons difficult. Some of the ‘palaeo-’ neologisms are a little annoying – what, for example, are ‘palaeodata’? Otherwise, the book is well produced, although the index is a little sparse. However, the price-tag will ensure this is mainly a book for libraries and only the most ardent of palaeohydrologists.

Journal of Biogeography, 1993

Progress in Physical Geography, 2007

... at Google Indexer on July 5, 2010 ppg.sagepub.com Downloaded from Page 6. Martin Kent: Biogeo... more ... at Google Indexer on July 5, 2010 ppg.sagepub.com Downloaded from Page 6. Martin Kent: Biogeography and landscape ecology 349 (Holderegger and Wagner, 2006). ... monitoring under the EU Natura 2000 initia-tive. Jongman et al. ...

Progress in physical geography, 2006

... DOI: 10.1191/0309133306pp489pr 2006 30: 399 Progress in Physical Geography Martin Kent Numeri... more ... DOI: 10.1191/0309133306pp489pr 2006 30: 399 Progress in Physical Geography Martin Kent Numerical classification and ordination methods in biogeography ... Kershaw, 1973; Greig-Smith, 1983; Kershaw and Looney, 1985; Gauch, 1982; Kent and Coker, 1992; Jongman et al ...

Applied Geography, 1982

ABSTRACT

Frontiers of Environmental Science & Engineering in China

Page 1. RESEARCH ARTICLE Spectral characteristics of plant communities from salt marshes: A case ... more Page 1. RESEARCH ARTICLE Spectral characteristics of plant communities from salt marshes: A case study from Chongming Dongtan, Yangtze estuary, China Liquan ZHANG (*)1, Zhanguo GAO1,2, Richard ARMITAGE3, Martin KENT4 ...

Seed Science Research, 2000

In Britain,Lobelia urens(L.) (the heath lobelia) occurs in rough grassland, is rare and only foun... more In Britain,Lobelia urens(L.) (the heath lobelia) occurs in rough grassland, is rare and only found in southern England, where it is at the northern limit of its range. Emergence and survival ofL. urenswas investigated at six locations in two geographically distinct sites experiencing spring, autumn or no grazing in two consecutive years. Four factors were evaluated qualitatively, as a means of characterizing microhabitats for germination and survival: all permutations of higher plant cover, bryophytes, plant litter and surface depressions. The potential effect of adjacent plants on recruitment was also assessed using the nearest neighbour distance (NND). Grazing created depressions, removed plant litter and increased the proportion of sites with higher plant cover. It also resulted in a more open sward with higher NNDs. None of these changes stimulated recruitment. Instead, small increases in the frequency of some rare or very rare microhabitat types were vital in making grazed roug...

Practical Ecology for Geography and Biology, 1985

Detailed surveys of vegetation often require data on species composition in addition to, or inste... more Detailed surveys of vegetation often require data on species composition in addition to, or instead of, structural or physiognomic descriptions. Such studies involve the identification of individual species and also the assessment of abundance of species. The techniques applied are known as floristic methods of vegetation description. The collection of data at the species level is fundamental to biogeography and ecology. Individual plant species are the building blocks of plant communities (see Section 2.3) and satisfactory survey and explanation of the distribution of communities as well as individual species requires floristic description. Also detailed appreciation of plant-environmental relationships and the effects of management of vegetation by man can often only be fully understood by a floristic survey.

Practical Ecology for Geography and Biology, 1985

Environmental pollution is now receiving a great deal of attention. It is of increasing concern n... more Environmental pollution is now receiving a great deal of attention. It is of increasing concern not just to biologists and ecologists, but also to many other professions including economists, planners, geographers and politicians. Pollution is a consequence of attitudes of mind, overpopulation and technological developments. Pollution is not a new problem, neither is it one which can be ignored. The nature and effects of pollution are variable, often being insidious rather than dramatic. Frequently people adopt, or are encouraged to adopt, a complacent or ‘optimistic ‘attitude to the problem. It is argued that pollution is a necessary and acceptable consequence of an important industrial or agricultural process, or that it is essential to the maintenance of employment. A common, but debatable assumption, is that in ‘good time’ the appropriate techniques will be developed to reduce or eliminate the problem.

The Geographical Journal, 1999

Practical Ecology for Geography and Biology, 1985

There is a natural curiosity to know what happens to the distribution of plants and animals outsi... more There is a natural curiosity to know what happens to the distribution of plants and animals outside the area which is well known to you. When it is necessary to establish the distribution of a particular taxon or community over hundreds or thousands of square kilometres, special procedures must be adopted. For example, many people are likely to become involved in the project and there may be problems of language or difficulties in communication. In addition, at these spatial scales the character of the ground mapping unit, within which individual surveys are being conducted, becomes extremely important.

Practical Ecology for Geography and Biology, 1985

This book is an introduction to four important aspects of ecology, environmental biology and biog... more This book is an introduction to four important aspects of ecology, environmental biology and biogeography: 1 to sources of information; 2 to methods of data collection; 3 to techniques of survey and mapping; 4 to the analysis and interpretation of biological and environmental data using simple statistical methods.

Practical Ecology for Geography and Biology, 1985

Vegetation and ecosystems are dynamic in nature. Plants form the food source for all other organi... more Vegetation and ecosystems are dynamic in nature. Plants form the food source for all other organisms and all food webs are ultimately dependent on the amount of plant tissue or biomass available for consumption. The rate of growth of plants varies greatly in response to the whole range of environmental limitations, but most notably climatic factors of solar radiation and moisture. Changes in growth rate are affected seasonally and also by the stage in the life cycle of a particular plant species. The amount of plant tissue which is accumulated in a given area over a certain period of time is known as the primary production or productivity. An important related concept is that of biomass or standing crop, which is the amount of plant tissue in a given area at one point in time. Most methods for measuring primary production are based on the repetition of biomass measurements at several points in time, with any increase in biomass representing the net primary production.

This paper presents a novel approach for the identification of suitable wetland restoration sites... more This paper presents a novel approach for the identification of suitable wetland restoration sites at a regional scale, using readily available soil and topographic data. The study focuses on Rhos pasture, a floristically diverse wet grassland community, which has been under threat from agricultural improvement in the past and more recently from neglect. The HOST classification was used to describe soil hydrological properties and topography was expressed using the ln(a/tanβ) topographic index. Distributions of soil hydrology and the topographic index under Rhos pasture sites were compared to the distributions of the total area and significance of the differences was assessed with chi-squared tests. Results were integrated into a decision support system, which predicted 72% of the existing sites. The method provides a useful tool for restoration planning at the decision-making scale.

Relationships between the distribution of animals and vegetation exist first because plants provi... more Relationships between the distribution of animals and vegetation exist first because plants provide the food source for many animals and represent the base of the trophic pyramid (see Section 2.2); and second because plants and vegetation act as a habitat within which many organisms live, grow and reproduce. For these reasons, relationships may be found between particular animal and plant species or vegetation types and this forms the justification for habitat survey methods (see Section 7.10). This type of association can be investigated and analysed very simply using the chi-squared (χ2) test. This test is often incorrectly termed the chi-square test.

Practical Ecology for Geography and Biology

The discussion of limiting factors in Section 2.4 showed that the distribution of both plant and ... more The discussion of limiting factors in Section 2.4 showed that the distribution of both plant and animal species and communities may be controlled by one or more environmental factors such as frequency of severe frost, available soil moisture, soil nutrient status, pollution, or by biotic pressures such as trampling or grazing. Although several factors may interact to control the distribution of a species, ultimately the nature of one factor, (the master limiting factor), will become critical and that species will no longer be able to survive.

Solute concentrations in throughfall, stem- flow, litterflow, soil water and springs were monitor... more Solute concentrations in throughfall, stem- flow, litterflow, soil water and springs were monitored in a sitka spruce (Picea sitchensis) forest and in a non- forested area. Analyses of stream water upstream and downstream of the afforested area revealed increased solute concentrations resulting from enhanced entrapment of atmospheric salts by the trees and increased weather- ing arising from the production of organic acids and chelates from decaying spruce needles. No significant difference in acidification upstream and downstream of the forest was observed. It was concluded that release of nutrients from litter decomposition balances nutrient uptake and the release of base cations by weathering buffers the system.

Global Ecology and Biogeography Letters

Progress in Physical Geography: Earth and Environment, 1997

The increasing relevance and importance of the subject of landscape ecology to bio geography are ... more The increasing relevance and importance of the subject of landscape ecology to bio geography are introduced. Research into landscape and plant community boundaries, never theless, remains comparatively neglected. In particular, the nature of those boundaries in terms of the patterns of floristic change and related ecosystem properties constitutes a potentially signifi cant new area of research for biogeographers. The term 'ecotone' has traditionally been used to describe boundaries between plant communities and ecosystems at a range of scales. Various definitions are presented and the often confusing terminology surrounding the word 'ecotone' is reviewed. Boundary types range from sharp, clearly defined boundaries (ecotones) between more highly modified plant communities and anthropogenically created land-use types at one extreme, to more gradual and diffuse boundaries (ecoclines) between natural and semi-natural plant communities at the other. It is proposed that th...

Progress in Physical Geography: Earth and Environment, 2000

and sedimentation. The latter study, developing on earlier work by Veldkamp, looks at the use of ... more and sedimentation. The latter study, developing on earlier work by Veldkamp, looks at the use of simple models to elucidate the relative significance of different processes in the formation of fluvial terraces, and is a useful illustration of the use of numerical models in the testing of hypotheses, development of theories and the indication of the focus of future field studies. The second section – ‘Palaeohydrological interpretations from depositional sequences and geomorphological changes’ – contains two case studies from The Netherlands, one from Siberia and one from Belarus. These studies focus on the Last Glacial period. Similarly, the third section, entitled ‘Palaeohydrology and environmental changes’, includes four case studies from Japan, Crete, Germany and Spain. ‘Late Pleistocene palaeohydrology’ has a distinctly Russian flavour. Two chapters consider the large-scale patterns and hydrological events of the Last Glacial period. In particular, the evidence for catastrophic outburst floods of the Glacial Lake Missoula type is presented, and suggests that this type of phenomenon occurred in a number of places throughout Eurasia. Although some of this evidence has been presented in English before, these chapters provide useful summaries of work to date. The third chapter is a modelling study of changes in the level of the Caspian Sea. Again the latter is a useful attempt, if only to point out the data limitations in trying to make such a reconstruction. The section on ‘Tropical zone palaeohydrology’ contains examples from both Africa and the Amazon Basin, mainly from a geomorphogical perspective. Finally, the four chapters in ‘Response of extreme events to climatic change’ consider examples from Poland, Syria and Spain. These studies tend to consider much shorter time periods than the other chapters in the book. However, given the significance of extreme events in the environments discussed, the chapters provide some useful indications of how research in this important area might progress. As with any volume of conference papers, one has to consider whether the whole is better than the sum of the parts. This book tends to lack coherence, but does have a number of useful themes running through it to make up for this problem. The focus on extreme and catastrophic events is one of these, of wider interest than hydrological investigations, with significant implications for the study of geomorphology and ecology as well as other disciplines. There is an increasing awareness of the need to link empirical data with observations from other sources, notably simulation models. Only by the iterative process successfully demonstrated in some of the chapters can the discipline of palaeohydrology as a whole hope to succeed. Perhaps further theoretical contributions along the lines of Baker’s would also be useful in pushing forward the subject. The complaints with the chapters are relatively few. There is still a tendency to use uncalibrated radiocarbon dates, despite the fact that calibrations are now available into and beyond the Last Glacial Maximum (in fact only one chapter uses the correct format). Apart from being incorrect such useage can make comparisons difficult. Some of the ‘palaeo-’ neologisms are a little annoying – what, for example, are ‘palaeodata’? Otherwise, the book is well produced, although the index is a little sparse. However, the price-tag will ensure this is mainly a book for libraries and only the most ardent of palaeohydrologists.

Journal of Biogeography, 1993

Progress in Physical Geography, 2007

... at Google Indexer on July 5, 2010 ppg.sagepub.com Downloaded from Page 6. Martin Kent: Biogeo... more ... at Google Indexer on July 5, 2010 ppg.sagepub.com Downloaded from Page 6. Martin Kent: Biogeography and landscape ecology 349 (Holderegger and Wagner, 2006). ... monitoring under the EU Natura 2000 initia-tive. Jongman et al. ...

Progress in physical geography, 2006

... DOI: 10.1191/0309133306pp489pr 2006 30: 399 Progress in Physical Geography Martin Kent Numeri... more ... DOI: 10.1191/0309133306pp489pr 2006 30: 399 Progress in Physical Geography Martin Kent Numerical classification and ordination methods in biogeography ... Kershaw, 1973; Greig-Smith, 1983; Kershaw and Looney, 1985; Gauch, 1982; Kent and Coker, 1992; Jongman et al ...

Applied Geography, 1982

ABSTRACT

Frontiers of Environmental Science & Engineering in China

Page 1. RESEARCH ARTICLE Spectral characteristics of plant communities from salt marshes: A case ... more Page 1. RESEARCH ARTICLE Spectral characteristics of plant communities from salt marshes: A case study from Chongming Dongtan, Yangtze estuary, China Liquan ZHANG (*)1, Zhanguo GAO1,2, Richard ARMITAGE3, Martin KENT4 ...

Seed Science Research, 2000

In Britain,Lobelia urens(L.) (the heath lobelia) occurs in rough grassland, is rare and only foun... more In Britain,Lobelia urens(L.) (the heath lobelia) occurs in rough grassland, is rare and only found in southern England, where it is at the northern limit of its range. Emergence and survival ofL. urenswas investigated at six locations in two geographically distinct sites experiencing spring, autumn or no grazing in two consecutive years. Four factors were evaluated qualitatively, as a means of characterizing microhabitats for germination and survival: all permutations of higher plant cover, bryophytes, plant litter and surface depressions. The potential effect of adjacent plants on recruitment was also assessed using the nearest neighbour distance (NND). Grazing created depressions, removed plant litter and increased the proportion of sites with higher plant cover. It also resulted in a more open sward with higher NNDs. None of these changes stimulated recruitment. Instead, small increases in the frequency of some rare or very rare microhabitat types were vital in making grazed roug...