David L. Hawksworth – författare

Proceedings of a NATO ARW held in Paris, France, May 11-14, 1993.

While biodiversity is a hot word, the conceptual scientific issues underlying its quantification have received scant attention. What is biodiversity? Is biodiversity just the number of species in an area? If biodiversity is more than this how can it be measured? Are all species of equal weight? Should biodiversity measures include intraspecific genetic variance? Do some species contribute more than others to the biodiversity of an area? Are there useful indicators of areas where biodiversity is high? And, can the extent of biodiversity be estimated by extrapolation? Leading experts in the field of biodiversity studies take up these questions in this Royal Society sponsored book. The contributors draw on examples from a wide range of groups of organisms including bacteria, beetles, birds, fungi, mammals, plants and spiders: palaeobotanical aspects are also considered. Approaches considered include the latest molecular and phylogenetic techniques through to a selection of indicator taxa and aspects of sampling.This text should be of interest to all those concerned with the practical tasks of biodiversity assessments and their interpretation, and also the development of the conceptual scientific base of this fledgling scientific discipline.

Periodic comprehensive overviews of the status of the diverse organisms that make up wildlife are essential to determining trends, threats and future prospects. Just over 25 years ago, leading authorities on different kinds of wildlife came together to prepare an assessment of their status of a wide range of organisms in Great Britain and Ireland in The Changing Flora and Fauna of Britain, also edited by Professor David L. Hawksworth CBE. Now, in The Changing Wildlife of Great Britain and Ireland, he has gathered together some of the original and also new contributors to review changes since that time and look to the future. Contributions range from viruses, diatoms, fungi, lichens, mites and nematodes; through butterflies, dragonflies, flies and slugs; to flowering plants, ferns, mammals, birds and fish. The state of knowledge in different groups is assessed, and the effectiveness of statutory and other measures taken to safeguard wildlife considered.The picture is far from bleak, ameliorating sulphur dioxide levels have benefited sensitive lichens and mosses in a dramatic way, water quality improvement has been beneficial, there have been few certain extinctions and rediscoveries of species thought to have been lost. Biodiversity Action Plans have also benefited targeted species, but habitat restoration and management for some is not always good for others.But there are worrying trends in declining populations, with an increasing number being regarded as threatened or endangered, especially in agricultural areas, and where woodland management has changed, particular threats from introduced species, and concern over the effects of climate change. Some of the smaller organisms remain poorly known, a situation unlikely to change as expertise in many is scant or being lost. This stock-check and look to the future will be a key source book to conservationists, naturalists, and professional biologists for many years to come.

Despite their enormous bulk and complexity of architecture, plants make up only around a quarter of a million of the 8 million or so species on Earth. The major components of biodiversity, instead, are the smaller, largely unseen, silent majority of invertebrates – most of which are arthropods. Vertebrates, a mere blip on the biotic horizon, are elevated in importance in the bigger scheme of things only by the human psyche.This collection of more than 30 peer-reviewed papers focuses on the diversity and conservation of arthropods, whose species inhabit virtually every recess and plane – and feature somewhere in virtually every food web – on the planet. Highlighting issues ranging from large-scale disturbance to local management, and from spatial heterogeneity to temporal patterns, these papers reflect some of the most exciting new research taking place today – and in some of the most biodiverse corners of the planet.

Drawing on diverse research from biodiversity experts around the world, this collection of papers reflects the diversity of forest types and forest issues that concern forest scientists globally.

This book gathers together a wide range of contributions addressing diverse aspects of front-line human involvement in biodiversity exploitation and conservation. As such they collectively provide a snap-shot of on-going action and state-of-the-art research, rather than a series of necessarily more superficial overviews. As such it is envisaged that it will be of particular interest to courses including biodiversity and/or conservation issues, and to advanced students and researchers working in related fields. The scope of these embraces cases involving birds, crop plants, invertebrates, land use changes, livestock, mammals, marine organisms, and medicinal plants. Issues related to the importance of gardens, hedges and green lanes, housing developments, hunting, invasive species, local community involvement, sacred groves, socioeconomic factors, and trade. Examples presented here come from studies in 17 countries including ones in Africa, Asia, Europe, and North and South America. All are topical cases to stimulate thoughts and future work programmes aiming to attain a sustainable balance between the conservation and sustainable exploitation of biodiversity.

Marine, coastal and wetland habitats are threatened, not only through exploitation, but also by the prospect of climate change – as ocean currents change course, sea levels rise, and rainfall patterns change. Even the once-common cod is now under threat from the combined effects of over-fishing and a dramatic change-induced decrease in the plankton that cod larvae feed on. Meanwhile, coral reefs remain especially vulnerable to rapid sea-level changes exacerbated by the effects of tourism and disease.This book gathers together a wide range of papers reporting on key research into the biodiversity conservation of these critical and increasingly threatened habitats. Collectively these papers provide a snap-shot of the types of problems they are experiencing, and offer a wealth of topical examples which render this volume especially valuable to teachers of courses in marine, freshwater and wetlands ecology, biological conservation and ecological restoration.

The structure and function of grasslands worldwide have been disrupted by habitat fragmentation, the removal of native grazers and altered ?re frequency (Samson and Knopf 1994). Such changes threaten the integrity of native grassland communities of plants and animals in many ways and at many levels (Janzen 1983; Collins 2000; Cully and Michaels 2000). Habitat fragmentation alters size, spacing and context of habitat patches, which can result in an increase in the local rate of extinction of plant and animal species by reducing fecundity, population size and colonization of species from similar habitats (Noss and Csuti 1992). Compounding the effects of fragm- tation, extirpation of ?re and loss of populations of native grazers can lead to encroachment of woody vegetation and loss of grassland (Leach and Givnish 1996; Collins et al. 1998). In addition to effects on plant communities, the use of prescribed ?re to enhance grasslands is of increasing relevance as regional losses, isolation and fragmentation of grasslands have led to corresponding declines in local population densities of many species of grassland-dependent birds (Askins 1993; Vickery et al. 1994). Ar- sensitive species in grasslands are especially vulnerable to these effects (Herkert 1994a, b) which can create speci?c physical, environmental and ecological changes (Yahner 1988) that lower habitat quality for area-sensitive species that have been historical specialists of grassland habitats.

Non-timber forest products (NTFP) hold economic and cultural signi?cance for millions of people across the globe. For instance, hundreds of millions of rural peoples currently derive a signi?cant portion of both their subsistence needs and cash income from gathered plant and animal products (Iqbal 1993; Vedeld et al. 2004). Thousands of wild NTFP are also harvested for local use in other cultural and religious activities, such as rituals, ceremonies and dances (e. g. FAO 1991). A growing body of literature has illustrated that NTFP harvest can have e- logical consequences at multiple ecological scales, and that demographic responses to harvest are heavily in?uenced by harvesting practices (see review by Ticktin 2004). However, although many NTFP are harvested from disturbed habitats and subject to multiple pressures (Cunningham 2001), few quantitative studies have addressed this issue. For example, a small number of studies have assessed the demographic effects of NTFP management practices in the context of browsing or grazing (Endress et al. 2004b; Ghimire et al. 2005), or human-induced ?re (Ticktin 2005). Nonetheless, the demographic consequences of NTFP harvest and mana- ment in the context of other disturbance factors, such as alien invasive species, have not been addressed to date.

This book brings together a selection of original studies submitted to Biodiversity and Conservation that address biodiversity and conservation in Europe. Europe is certainly the most intensively inventoried region of the world; detailed maps are available for species distributions while action plans are being drawn up for species under threat. At the same time, the wildlife of Europe has been subject to enormous human pressures, with limited ‘wilderness’ sites remaining in most countries. Europe consequently presents a case-study of what the human impact on biodiversity has been, and also what can be done to improve the situation.The contributions in this volume are drawn from a wide range of countries and discuss diverse organism and habitat types. They collectively provide a snap-shot of the sorts of studies and actions being taken in Europe to address issues in biodiversity and conservation – topical examples that will make the volume especially valuable for use in conservation biology courses.

Proceedings of a NATO ARW held in Paris, France, May 11-14, 1993.

This book covers a broad spectrum of topics related to GMOs and allied new gene-based technologies, biodiversity, and ecosystem processes, bringing together the contributions of researchers and regulators from around the world.

This book covers a broad spectrum of topics related to GMOs and allied new gene-based technologies, biodiversity, and ecosystem processes, bringing together the contributions of researchers and regulators from around the world.

Despite their enormous bulk and complexity of architecture, plants make up only around a quarter of a million of the 8 million or so species on Earth. The major components of biodiversity, instead, are the smaller, largely unseen, silent majority of invertebrates – most of which are arthropods. Vertebrates, a mere blip on the biotic horizon, are elevated in importance in the bigger scheme of things only by the human psyche.This collection of more than 30 peer-reviewed papers focuses on the diversity and conservation of arthropods, whose species inhabit virtually every recess and plane – and feature somewhere in virtually every food web – on the planet. Highlighting issues ranging from large-scale disturbance to local management, and from spatial heterogeneity to temporal patterns, these papers reflect some of the most exciting new research taking place today – and in some of the most biodiverse corners of the planet.

Natural forests with thousands of years of ecological continuity are unrivalled as the treasure store of terrestrial biodiversity on Earth. And while there is currently no fully comprehensive inventory of the biota associated with any given forest, it is reasonable to assume that in conserving natural forests we can conserve the myriads of unnamed bacteria, fungi, insects, mites and nematodes that forests support. Drawing on diverse research from biodiversity experts around the world, this collection of papers reflects the diversity of forest types and forest issues that concern forest scientists globally. Forest types considered vary from savannah and tropical rainforests to the ancient oak forests of Poland; issues explored include the effects of logging, management practices, forest dynamics and climate change on forest structure and biodiversity.

This book gathers together a wide range of contributions addressing diverse aspects of front-line human involvement in biodiversity exploitation and conservation. As such they collectively provide a snap-shot of on-going action and state-of-the-art research, rather than a series of necessarily more superficial overviews. As such it is envisaged that it will be of particular interest to courses including biodiversity and/or conservation issues, and to advanced students and researchers working in related fields. The scope of these embraces cases involving birds, crop plants, invertebrates, land use changes, livestock, mammals, marine organisms, and medicinal plants. Issues related to the importance of gardens, hedges and green lanes, housing developments, hunting, invasive species, local community involvement, sacred groves, socioeconomic factors, and trade. Examples presented here come from studies in 17 countries including ones in Africa, Asia, Europe, and North and South America. All are topical cases to stimulate thoughts and future work programmes aiming to attain a sustainable balance between the conservation and sustainable exploitation of biodiversity.

Marine, coastal and wetland habitats are threatened, not only through exploitation, but also by the prospect of climate change – as ocean currents change course, sea levels rise, and rainfall patterns change. Even the once-common cod is now under threat from the combined effects of over-fishing and a dramatic change-induced decrease in the plankton that cod larvae feed on. Meanwhile, coral reefs remain especially vulnerable to rapid sea-level changes exacerbated by the effects of tourism and disease.This book gathers together a wide range of papers reporting on key research into the biodiversity conservation of these critical and increasingly threatened habitats. Collectively these papers provide a snap-shot of the types of problems they are experiencing, and offer a wealth of topical examples which render this volume especially valuable to teachers of courses in marine, freshwater and wetlands ecology, biological conservation and ecological restoration.

The structure and function of grasslands worldwide have been disrupted by habitat fragmentation, the removal of native grazers and altered ?re frequency (Samson and Knopf 1994). Such changes threaten the integrity of native grassland communities of plants and animals in many ways and at many levels (Janzen 1983; Collins 2000; Cully and Michaels 2000). Habitat fragmentation alters size, spacing and context of habitat patches, which can result in an increase in the local rate of extinction of plant and animal species by reducing fecundity, population size and colonization of species from similar habitats (Noss and Csuti 1992). Compounding the effects of fragm- tation, extirpation of ?re and loss of populations of native grazers can lead to encroachment of woody vegetation and loss of grassland (Leach and Givnish 1996; Collins et al. 1998). In addition to effects on plant communities, the use of prescribed ?re to enhance grasslands is of increasing relevance as regional losses, isolation and fragmentation of grasslands have led to corresponding declines in local population densities of many species of grassland-dependent birds (Askins 1993; Vickery et al. 1994). Ar- sensitive species in grasslands are especially vulnerable to these effects (Herkert 1994a, b) which can create speci?c physical, environmental and ecological changes (Yahner 1988) that lower habitat quality for area-sensitive species that have been historical specialists of grassland habitats.

Non-timber forest products (NTFP) hold economic and cultural signi?cance for millions of people across the globe. For instance, hundreds of millions of rural peoples currently derive a signi?cant portion of both their subsistence needs and cash income from gathered plant and animal products (Iqbal 1993; Vedeld et al. 2004). Thousands of wild NTFP are also harvested for local use in other cultural and religious activities, such as rituals, ceremonies and dances (e. g. FAO 1991). A growing body of literature has illustrated that NTFP harvest can have e- logical consequences at multiple ecological scales, and that demographic responses to harvest are heavily in?uenced by harvesting practices (see review by Ticktin 2004). However, although many NTFP are harvested from disturbed habitats and subject to multiple pressures (Cunningham 2001), few quantitative studies have addressed this issue. For example, a small number of studies have assessed the demographic effects of NTFP management practices in the context of browsing or grazing (Endress et al. 2004b; Ghimire et al. 2005), or human-induced ?re (Ticktin 2005). Nonetheless, the demographic consequences of NTFP harvest and mana- ment in the context of other disturbance factors, such as alien invasive species, have not been addressed to date.