Long-Term Forest Dynamics of the Temperate Zone


Book Description

The synthesis presented in this volume is a direct outgrowth of our ten-year FORMAP Project (Forest Mapping Across Eastern North America from 20,000 yr B.P. to the Present). Many previous research efforts in paleoecology have used plant-fossil evidence as proxy information for primarily geologic or climatic reconstructions or as a bio stratigraphic basis for correlation of regional events. In contrast, in this book, we deal with ecological questions that require a holistic perspective that integrates the interactions of biota with their dynamically changing environments over time scales up to tens of thousands of years. In the FORMAP Project, our major research objective has been to use late-Quaternary plant-ecological data sets to evaluate long-term patterns and processes in forest de velopment. In order to accomplish this objective, we have prepared subcontinent-scale calibrations that quantitatively relate the production and dispersal of arboreal pollen to dominance in the vegetation for the major tree types of eastern North America. Quantification of pollen-vegetation relationships provides a basis for developing quan titative plant-ecological data sets that allow further ecological analysis of both individual taxa and forest communities through time. Application of these calibrations to fossil pollen records for interpreting forest history thus represents a fundamental step beyond traditional summaries based upon pollen percentages.




Forest Dynamics and Disturbance Regimes


Book Description

Lee Frelich provides a major contribution to the study of temperate-zone forest dynamics by considering three important themes: the combined influence of wind, fire, and herbivory on the successional trajectories and structural characteristics of forests; the interaction of deciduous and evergreen tree species to form mosiacs; and the significance of temporal and spatial scale with regard to the overall impact of disturbances. These themes are explored via case studies from the forests in the Lake States of Minnesota, Wisconsin and Michigan, where the presence of large primary forest remnants provides a unique opportunity to study the long-term dynamics of near-boreal, pine, and hardwood-hemlock forests.




Forest Dynamics and Disturbance Regimes


Book Description

Temperate-zone forests are being shaped continuously by wind, fire and grazing. This book considers these disturbances and consequent issues such as recovery from disturbance, the changing composition of tree species within the forest and the formation of mosaics of different forest types across the landscape.







Deforesting the Earth


Book Description

Since humans first appeared on the earth, we've been cutting down trees for fuel and shelter. Indeed, the thinning, changing, and wholesale clearing of forests are among the most important ways humans have transformed the global environment. With the onset of industrialization and colonization the process has accelerated, as agriculture, metal smelting, trade, war, territorial expansion, and even cultural aversion to forests have all taken their toll. Michael Williams surveys ten thousand years of history to trace how, why, and when human-induced deforestation has shaped economies, societies, and landscapes around the world. Beginning with the return of the forests to Europe, North America, and the tropics after the Ice Ages, Williams traces the impact of human-set fires for gathering and hunting, land clearing for agriculture, and other activities from the Paleolithic through the classical world and the Middle Ages. He then continues the story from the 1500s to the early 1900s, focusing on forest clearing both within Europe and by European imperialists and industrialists abroad, in such places as the New World and India, China, Japan, and Latin America. Finally, he covers the present-day and alarming escalation of deforestation, with the ever-increasing human population placing a possibly unsupportable burden on the world's forests. Accessible and nonsensationalist, Deforesting the Earth provides the historical and geographical background we need for a deeper understanding of deforestation's tremendous impact on the environment and the people who inhabit it.




If the Trees Burn, is the Forest Lost?


Book Description

Forest dynamics are driven by top-down changes in climate and bottom-up positive (destabilizing) and negative (stabilizing) biophysical feedbacks involving disturbance and biotic interactions. When positive feedbacks prevail, the resulting self-propagating changes can potentially shift the system into a new state, even in the absence of climate change. Conversely, negative feedbacks help maintain a dynamic equilibrium that allows communities to recover their pre-disturbance characteristics. We examine palaeoenvironmental records from temperate forests to assess the nature of long-term stability and regime shifts under a broader range of environmental forcings than can be observed at present. Forest histories from northwestern USA, Patagonia, Tasmania and New Zealand show long-term trajectories that were governed by (i) the biophysical template, (ii) characteristics of climate and disturbance, (iii) historical legacies that condition the ecological capacity to respond to subsequent disturbances, and (iv) thresholds that act as irreversible barriers. Attention only to current forest conditions overlooks the significance of history in creating path dependency, the importance of individual extreme events, and the inherent feedbacks that force an ecosystem into reorganization. A long-time perspective on ecological resilience helps guide conservation strategies that focus on environmental preservation as well as identify vulnerable species and ecosystems to future climate change. This article is part of the theme issue ?Climate change and ecosystems: threats, opportunities and solutions?.













Oak Seed Dispersal


Book Description

Theimer, an accomplished ecologist.