Biology

Bees play a vital role as pollinators for many agricultural crops. This book discusses the interplay between bees, agriculture, and the environment. Although honey bees are well recognized as pollinators, managed bumble bees and solitary bees are also critical for the successful pollination of certain crops, while wild bees provide a free service. As bees liberally pass pollen from one plant to the next, they also impact the broader ecosystem, and not always to the benefit of humankind. Bees can enhance the unintentional spread of genes from genetically engineered plants, and may increase the spread of invasive weeds. Conversely, genetically engineered plants can impact pollinators, and invasive weeds can supply new sources of food for these insects. Bees' flower-visiting activities also can be exploited to spread biological control agents that help to control crop pests. Bee pollination is important for production of native plants used for restoration of wild lands. Managing bees for pollination is complex and must consider bee natural history, physiology, pathology, and behavior. Furthermore, transporting bees from native ranges to new areas for pollination services can be controversial, and should be done only after assuring that a non-native bee introduction will not disrupt the ecosystem. Even though bees are small, unobtrusive creatures, they play large roles in the ecosystem. The connection between bees and humankind is symbolic of a broader interconnection between humans and the natural world.

Ecologists, both practical and theoretical, now appreciate that to understand biological systems they must consider the spatial dimension. Consequently, dispersal has become one of the hottest topics in plant ecology. However, in the midst of so much research output on dispersal, there is a need for a stock-take to determine the needs of future research: what has been achieved to date, where do current studies fit in, and what still needs to be determined? What are the implications of dispersal for those engaged in managing plant populations and communities? This is the first book for many years to present a synthesis of research on dispersal and its implications for plant population dynamics. The book consists of three sections: Section A reviews information on the biological and environmental processes that determine the path of an individual dispersing propagule, usually a seed, and the theory that has been developed to predict these trajectories; Section B discusses the distributions of seeds resulting from dispersal from an entire plant, theoretical research predicting the shapes of these distributions and design issues for future dispersal studies; Section C explores the implications of dispersal for expansion of populations, structure within existing populations and communities, and the evolution of dispersal traits.

This book aims to provide a critical appraisal of the theory and practice of key methods of forest pest management. The appropriate application of these ‘ecological methods’ in the development of Integrated Pest Management (IPM) programmes depends on a clear understanding of pest biology and population dynamics, and an appreciation of the ecology and economic importance of both semi-natural and plantation forests. These aspects provide a focus for discussion throughout the book. The main themes of the first four chapters are the influence of forest composition and structure on the nature and severity of pest problems, the threat posed by the introduction of exotic pests in global trade, how risk-rating of forests can provide an early warning of outbreaks, and the role that silviculture can play in both contributing to and helping to reduce the impact of pests. The following four chapters discuss in turn the nature of tree resistance and its exploitation, the principles and practice of biological and microbial control, and the use of semiochemicals in manipulating insect populations. The final chapter on IPM includes a discussion of the economic and environmental impact of pests, with practical examples of IPM illustrated in a series of case studies. The potential impact of climate change is briefly discussed. Many of the examples and case studies relate to insect pests, but the term ‘pest’ is used in its widest sense to include fungal pathogens. Brief reference is also made to mammalian herbivores.

Forest conservation has become one of the most important environmental issues currently facing humanity, as a result of widespread deforestation and forest degradation. Pressures on remaining natural forests continue to intensify, leading to high rates of biodiversity loss. Understanding how human activities influence ecological processes within forests is essential for developing effective conservation action. This book describes research methods and techniques relevant to understanding forest ecology, with a particular focus on those that are relevant to practical conservation and sustainable forest management. This information is currently disparate and difficult to locate, and the intention here is to provide a comprehensive synthesis. Methods are presented for assessing forest extent and condition, structure and composition, and forest dynamics at a variety of scales. Techniques for assessing genetic variation and reproductive ecology, and for evaluating the habitat value of forests are also described. Particular emphasis is given to state-of-the-art techniques, such as remote sensing, GIS, computer modelling, and molecular markers. However, traditional methods of forest mensuration and ecological survey are also presented. The methods and techniques described are generally applicable to all forest types, including both temperate and tropical forest ecosystems.

This book provides sampling designs for measuring species richness and diversity, patterns of plant diversity, species-environment relationships, and species distributions in complex landscapes and natural ecosystems. Part I introduces the problem: plant diversity studies are difficult to design and conduct in part because of the history and baggage associated with the evolution of plant ecology into a quantitative science. Issues of scale, resolution, and extent must be effectively commandeered. Part II implores the practitioner to take an experimental approach to sampling plant diversity with a clear understanding of advantages and disadvantages of single-scale and multi-scale techniques. Part III focuses on scaling plant diversity measurements from plots to landscapes. Part IV provides a brief introduction to modeling plant diversity in relation to environmental factors. Examples of common non-spatial (correlative) and spatial analyses are explained. Part V introduces the concept of measuring temporal changes in plant diversity at landscape scales and follows with a case study designed to collect the necessary baseline data to monitor plant diversity. Part VI discusses research needed to understand better changes in plant diversity in space and time. Specific objectives are to: (1) provide a basic understanding of the history of design considerations in past and modern vegetation field studies; (2) demonstrate with real-life case studies the use of single-scale and multi-scale sampling methods, and statistical and spatial analysis techniques that may be particularly helpful in measuring plant diversity at landscape scales; and (3) address several sampling questions typically asked by students and field ecologists.

This book surveys the momentous morphological change in plant evolution that created the terrestrial biosphere as we know it today. It takes as its premise that the study of plant evolution at its grandest is the study of how mutations in genes have changed the way the planet functions. The evolution of the leaf, for instance, change terrestrial carbon cycling and primary productivity, so changing the earth's atmosphere and the distribution of carbon. The book charts the rise to complexity of the three many organs systems of complex land plants, the axis or stem, the leaf, and the root. These organs system are surveyed morphologically in the light of empirical morphology, in which organ concepts are considered as hypotheses to be tested in a developmental, molecular, and phylogenetic framework. It also tackles the evolution of the seed (via heterospory and covering of the megasporangium) and the flower (by complex patterning of sporophylls and sterile phyllomes). All this is placed where possible in its molecular context, with the aim of demonstrating how evolving gene networks have given rise to increasing morphological complexity.

Mushrooms are the most wondrous inventions of the last billion years of evolutionary history on earth. Their overnight appearance is a pneumatic process, with the inflation of millions of preformed cells extending the stem, pushing earth aside, and unfolding a cap above the dewy grass. Once exposed, a mushroom's gills shed an astonishing 30,000 spores per second, delivering billions of microscopic particles into the air in a single day, cells that may be capable of spawning the largest organisms on the planet. Mushroom colonies burrow through soil and rotting wood. Some hook into the roots of forest trees and engage in mutually supportive symbioses; others are pathogens that decorate their food sources with hardened hooves and fleshy shelves. Among the staggering diversity of mushroom-forming fungi we find stranger apparitions including gigantic puffballs, phallic eruptions with revolting aromas, and tiny “bird's nests” whose spore-filled eggs are splashed out by raindrops. But it is the poisonous effects of a handful of fungal metabolites, and the powerful hallucinogenic qualities of others, which account for the central place of mushrooms in mythology and their commonest associations in Western culture. This book explains what mushrooms are (Chapter 1), how they work (Chapter 2), and what their underlying colonies do (Chapter 3); the harvesting and conservation of wild mushrooms and the cultivation of domesticated species are addressed in Chapters 4 and 5, the science of poisonous and hallucinatory fungi in Chapters 6 and 7, and deceptive claims about medicinal mushrooms in Chapter 8.

This book provides an overview of human-plant interactions and their social consequences, from the hunter-gatherers of the Palaeolithic Era to the 21st century molecular manipulation of crops. It links the latest advances in molecular genetics, climate research, and archaeology to give a new perspective on the evolution of agriculture and complex human societies across the world. Even today, our technologically advanced societies still rely on plants for basic food needs, not to mention clothing, shelter, medicines, and tools. This special relationship has tied together people and their chosen plants in mutual dependence for well over 50,000 years. Yet despite these millennia of intimate contact, people have only domesticated and cultivated a few dozen of the tens of thousands of edible plants. Crop domestication and agriculture then led directly to the evolution of the complex urban-based societies that have dominated much of human development over the past ten millennia. Thanks to the latest genomic studies, how, when, and where some of the most important crops came to be domesticated can now be explained, and the crucial roles of plant genetics, climatic change, and social organization in these processes. Indeed, it was their unique genetic organizations that ultimately determined which plants eventually became crops, rather than any conscious decisions by their human cultivators.

This book integrates a diverse and scattered literature to produce a synthetic account of plant evolutionary ecology. The central theme is differentiation, both among and within species, in the contemporary flora of the Mediterranean basin. This theme is developed by linking population processes to species evolution, and by examining the variation and evolution of ecological function in the context of spatial habitat variation and regional history. The Mediterranean is a region with a complex geological and climatic history, and a highly heterogeneous landscape in which human activities have greatly modified local conditions and the spatial configuration of habitats. This book explores the evolutionary processes that have shaped plant evolution in the context of these major influences on vegetation. The book is structured around two central topics in evolutionary ecology: diversity and adaptation. The Mediterranean region is a hotspot of plant biodiversity, a key ingredient of which is its richness in endemic species. A primary question motivating this book concerns the role of historical factors and spatial environmental variation in the evolution of such endemism. The Mediterranean landscape is also characterized by dramatic variations in ecological conditions, often over short distances. A second focus is on the ecological and historical factors that mediate dispersal, reproduction, and adaptive trait variation in the Mediterranean mosaic.

In modern agricultural politics, organic farming and genetic engineering occupy opposite ends of the spectrum. In the Ronald-Adamchak household, the world is not so black and white. Ronald is a professor of plant genetics at the University of California, Davis. Adamchak manages the student-run organic farm. Together, they're exploring the juncture where their methods can meet to ensure ecologically friendly farming. This book roughly chronicles one year in their lives. Through dialogue with friends and family, the authors thoughtfully explore the use of GE crops. The authors discuss the contents of their own pantry, what they choose to feed their children, and criteria for the use of GE in agriculture. From their personal vantage points, Ronald and Adamchak explain what geneticists and organic farmers actually do, and help readers distinguish between fact and fiction in the debate about GE crops. Each section of the book addresses a different issue related to the role of GE and organic farming in food production. Ronald provides a farmer's view of the philosophy and practice of organic farming and how it differs from conventional agriculture; Adamchak describes the tools and processes of genetic engineering, the potential ecological benefit of using GE technology to generate plants, and the associated risks. At the end of the book, they describe one of their typical family dinners, explain their choice to bring both genetically engineered and organic food to their table, and share some of their family's best recipes.