A Resource-Based Habitat View for Conservation

Winner of the Marsh Book of the Year Award 2012 by theBritish Ecological Society. In A Resource-Based Habitat View for Conservation RogerDennis introduces a novel approach to the understanding of habitatsbased on resources and conditions required by organisms and theiraccess to them, a quantum shift from simplistic andineffectual notions of habitats as vegetation units or biotopes. Indrawing attention to what organisms actually use and need inlandscapes, it focuses on resource composition, structure andconnectedness, all of which describe habitat quality and underpinlandscape heterogeneity. This contrasts with the current bipolarview of landscapes made up of habitat patches and empty matrix butillustrates how such a metapopulation approach of isolatedpatchworks can grow by adopting the new habitat viewpoint. The book explores principles underlying this newdefinition of habitat, and the impact of habitat components onpopulations, species' distributions, geographical ranges andrange changes, with a view to conserving resources in landscapesfor whole communities. It does this using the example ofbutterflies - the most alluring of insects, flagship organisms andkey indicators of environmental health - in the British Isles,where they have been studied most intensively. The book formsessential reading for students, researchers and practitioners inecology and conservation, particularly those concerned withmanaging sites and landscapes for wildlife.

Auteur

ROGER DENNIS is currently an Honorary Visiting Professor at Staffordshire University and an Honorary Research Fellow at both NERC's Centre for Ecology and Hydrology, Wallingford, and in the School of Life Sciences at Oxford Brookes University; he serves on the editorial board of four journals. He has received a succession of honorary research fellowships during which he has studied butterfly biogeography and ecology, producing over 175 publications. In 2006, he received the Marsh Award for Lifetime Achievement in Lepidoptera Conservation.

Texte du rabat
In A Resource-Based Habitat View for Conservation Roger Dennis introduces a novel approach to the understanding of habitats based on resources and conditions required by organisms and their access to them, a quantum shift from simplistic and ineffectual notions of habitats as vegetation units or biotopes. In drawing attention to what organisms actually use and need in landscapes, it focuses on resource composition, structure and connectedness, all of which describe habitat quality and underpin landscape heterogeneity. This contrasts with the current bipolar view of landscapes made up of habitat patches and empty matrix but illustrates how such a metapopulation approach of isolated patchworks can grow by adopting the new habitat viewpoint. The book explores principles underlying this new definition of habitat, and the impact of habitat components on populations, species' distributions, geographical ranges and range changes, with a view to conserving resources in landscapes for whole communities. It does this using the example of butterflies the most alluring of insects, flagship organisms and key indicators of environmental health in the British Isles, where they have been studied most intensively. The book forms essential reading for students, researchers and practitioners in ecology and conservation, particularly those concerned with managing sites and landscapes for wildlife. Companion website available at www.wiley.com/go/dennis/butterflies

Résumé
A RESOURCE-BASED HABITAT VIEW FOR CONSERVATION In A Resource-Based Habitat View for Conservation Roger Dennis introduces a novel approach to the understanding of habitats based on resources and conditions required by organisms and their access to them, a quantum shift from simplistic and ineffectual notions of habitats as vegetation units or biotopes. In drawing attention to what organisms actually use and need in landscapes, it focuses on resource composition, structure and connectedness, all of which describe habitat quality and underpin landscape heterogeneity. This contrasts with the current bipolar view of landscapes made up of habitat patches and empty matrix but illustrates how such a metapopulation approach of isolated patchworks can grow by adopting the new habitat viewpoint. The book explores principles underlying this new definition of habitat, and the impact of habitat components on populations, species' distributions, geographical ranges and range changes, with a view to conserving resources in landscapes for whole communities. It does this using the example of butterflies the most alluring of insects, flagship organisms and key indicators of environmental health in the British Isles, where they have been studied most intensively. The book forms essential reading for students, researchers and practitioners in ecology and conservation, particularly those concerned with managing sites and landscapes for wildlife. Companion website available at www.wiley.com/go/dennis/butterflies

Contenu
Foreword by Dr Martin Warren viii

Preface ix

Acknowledgements xi

1 WHAT IS A HABITAT? AN AWKWARD QUESTION 1

Definitions of habitat 1

Distinguishing habitat from biotope and vegetation units 2

2 A SIMPLE MODEL FOR BUTTERFLY HABITATS 9

Habitat model 9

Key issues in the habitat model 14

The matrix or so-called empty space 14

Movement in and between habitats 14

Open versus closed populations and species 14

Qualifying resource outlets 15

Consumables 23

Larval hostplants and herbivory 23

Nectar sources and adult food 25

Utilities 27

Adult basking sites and behaviour 29

Mate location sites substrates and behaviour 31

Egg-laying sites and substrates 34

Adult rests and roosts 35

Larval sites for resting and moulting 37

Pupation sites 38

Parasitoids and predators in the resource zones 39

Symbionts and enemy-free space 41

Hibernation and aestivation sites 42

Conditions and conditioners 44

Climatic agents as conditioners 44

Edaphic agents as conditioners 51

Resource database 52

3 BASIC PRINCIPLES FOR BUTTERFLY HABITATS 53

Describing variation in resources 53

Resource composition 53

Resource physiognomy 56

Resource connectivity 59

Resource variation in the habitat space 59

General principles of resource composition 59

General principles of resource physiognomy 60

General principles of resource connectivity 61

Resource dynamics within habitats 62

General principles of resource dynamics 63

General principles of resource composition 66

General principles of resource physiognomy 67

General principles of resource connectivity 67

Habitats butterfly resources and population status 68

Resource dynamics population status and life cycle strategies 74

Principles relating to population size and density 75

Principles relating to stage appearance 75

Resources movements and dispersion patterns inside the habitat 77

4 EXPLOITING INDIVIDUAL RESOURCES 79

Patterns and agents in resource use 79

Some principles relating to single resource use 79

Principles relating to spatial variation in a resource type 80

Principles relating to temporal variation in single resource types 84

Principles relating to individual preferences and behaviour 86

Distribution of individuals in relation to the distribution of resources 87

Distribution of individuals on single resource patches 90

Placement of individual butterflies on single resource items 94

Manipulation of the micro-landscape: micro-architecture 95

Foraging: theory and practice 97

5 BUTTERFLY HABITATS: SEARCHING FOR ORDER 100

Biotope distinctions among British butterflies 101

Biotope associations 101

Principles of biotope properties 103

Principles linking butterflies to biotopes 106

Principles relating to observations made in bio…