BOOK REVIEWS

Climate Change and Human Impact on the Landscape. F. M. Chambers (Editor), 1993, Chapman and Hall, xxi + 303 pp., $97.00 (hardbound).

Climate change and human action have influenced, separately or in concert, the development of vegetation and landscapes worldwide. For the paleoecologist several questions naturally follow: Can we distinguish climatic from anthropogenic effects in the geologic record, and can we determine when they have interacted to create a particular set of conditions? Scientific philosophies and traditions, the tools available to paleoecologists, and site-specific factors all qualify our answers, as the contributions to this volume effectively illustrate. Most of the examples are from Britain, and from the North American viewpoint they clearly illustrate differences in approach between European and North American scientists.

The inspiration for the book is the work of Professor Alan Smith. In a long and distinguished career in Britain and Northern Ireland, he has considered many aspects of how human impact and climatic change influence landscape evolution. He also played a key role in developing applications of radiocarbon and dendrochronological techniques to paleoecological studies. Chapters by a wide range of authors examine the current limits of paleoecology, developments in environmental archaeology, and technique and interpretation in the light of new practical and theoretical developments.

The book has four parts. The first addresses the spatial and temporal limits of paleoecological studies that address human impact. Birks reminds us that, to appreci- ate the historical record of human impact on the environment, we must work a t high levels of spatial and temporal resolution to separate the interacting roles of people, climate, and ecological processes. Chapters by Pilcher and Baillie show how AMS dating and refined tree-ring techniques now allow us to describe various human activities with much greater temporal precision than before; in particular, tree rings can sometimes provide details as to the season, as well as the year, of various human activities. The precision possible in this kind of paleoecology not only affords us reconstructional detail, but it also lends itself to the deductive approach; Oldfield reminds us that, with good control over chronology and data, we are in a position to test hypotheses rather than merely to generate empirical data for post hoc interpretation.

The second part on climatic change is the least convincing. In contrast t o human impact, patterns of climate change emerge a t large geographic scales. At the smaller scales addressed in this book the role of climate is often ambiguous, and local change in the records actually becomes noise that obscures the climate signal. Blackford and Matthews tackle the problems posed by peat bogs and arctic-alpine soils, repectively, as repositories of climatic information; the conclusion is that neither are tractable systems. Lowe demonstrates that even a regional vegetation history for Scotland needs a still larger geographic context in order to extract climatic information reliably. However, Bradshaw provides an interesting set of examples that illustrate the complex interaction of climate, ecological processes, and humans, and shows that in the right context these factors can be distinguished in the record. Bradshaw reminds us that fire is perhaps one of the most important factors that mediates vegetation response to climate; as fire is used by humans in many contexts, its application (or suppression) can alter the climate-vegetation relationship in a

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particular system. Several authors touch on this theme in the following section, which focuses on human impact.

The main approach to studying human impact on the environment has been via pollen analysis and associated chronologic and stratigraphic techniques. The vagaries of pollen representation and the limits to sampling resolution often veil past changes in such factors as species diversity and soil quality, which we would consider important consequences of human impact if we were to observe them today. Improved techniques are allowing us to discern these more subtle effects of past human impact, and a t the same time we are broadening the scope of what we consider human impact to be. The consequence is that we now understand that anthropogenic disturbances affected landscapes earlier than previously thought, and systems considered “natural” may not be-quite. This can have direct relevance to current issues of biodiversity and conservation.

Papers by Simmons, Caseldine and Hatton, K. J. Edwards, Evans, and Wiltshire and K. J. Edwards all address aspects of the British Mesolithic. With varying degrees of conviction they conclude that Mesolithic people did have a detectable effect on their surroundings. This pushes back the accepted time limits on known human impact on the environment from the Neolithic to the Mesolithic.

For example, Caseldine and Hatton demonstrate that fire was used to keep a wooded Mesolithic Dartmoor partially open, prior to a major vegetational transformation to acidic moorland. They also provide evidence of the intermediate stages in this transfor- mation from woodland through grassland to moorland, and suggest that the landscape was predisposed to the change; even if human pressure had been subsequently reduced, the changes were already irreversibly set in motion. Such a pattern is familiar in many parts of the world today where landscape degradation is taking place.

K. J. Edwards provides an interesting review of early farming models. The original landnarn model for the Neolithic, while still undoubtedly valid, has been superceded by models based less on land clearance and more on forest gardening. The underlying assumption is that the forest was a hospitible place for early peoples, not a wilderness to be cut down. Although not explicitly stated, this seems to underscore a change in our own cultural values and perhaps reflects our increased knowledge of the ways some modern human communities relate to their environment. Needless to say, very subtle interpretations of the pollen record are required to “see” the actions of these earlier peoples.

Evans uses fossil molluscs to examine human activity on the chalklands of southern Britain. He describes soil and successional changes and the details of the emplacement of monuments, camps, etc., in relation to the local vegetation-soil mosaic. In a fine example of the detail that can be obtained in this kind of study, Molloy and O’Connell document the recent history of a site in western Ireland that was probably first cleared for ritual use rather than for farming.

In the only paper in this section to address the human impact issue worldwide, Walker and Singh discuss regions such as southeast Asia, which have much longer records of human disturbance than northwest Europe. They challenge North Americans to reexamine their own records (and assumptions) about early human impact on the landscape, and predict that we will find that there was more transformation prior to European settlement than we currently allow.

Finally, we come to the section in which climate and humans unite in their effect on vegetation. Huntley is the only author to follow Birks and Oldfield by developing

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working hypotheses and attempting to test them. His question concerns the rapid increase of hazel (Corylus) across Europe in the early post-glacial-a continental-scale question that must be explained by influences operating a t the same scale. In the final analysis human action is considered an unlikely agent for the rapid spread of hazel.

The following three chapters deal with mires. Moore revisits his blanket mire hypothe- sis (that is, human clearance of upland forests changed the hydrologic balance and caused mire development over previously wooded landscapes). Evidence still lines up in favor of the hypothesis, and Moore develops a conceptual model (it would be interest- ing to add some numbers). He points out that pollen evidence from Norway also links cultural activity to formation of some blanket mires; it is possible that such mires form the earliest large-scale anthropogenic landscapes in northwest Europe. Barber et al. look at human activity in northern Britain from Roman times onward as recorded by peat bogs. They find human activity more related to sociohistorical events than climate (if one can really tell anything about climate from peat bogs-see Blackford). Warner, in the one contribution from North America, shows how European settlement activities in Ontario led to changes in hydrology and nutrient supply and the eventual develop- ment of new ecosystems-floating bogs. Previously these had been interpreted as long- lived natural systems supporting glacial relict vegetation.

In the final chapter, the editor faces the challenging task of bringing the different themes of the book together. His summary of recent developments in paleoclimatic studies is a useful addition. However, I must take issue with his perpetuation of the notion of a highly productive Beringia, without periglacial features, at the time of the last glacial maximum. The “mammoth steppe” is only one hypothesis as to the nature of that landscape. Extreme periglacial features occur in the geologic record. The paleo- ecological data (mammalian remains and palynological records) are inconsistent and suggest relatively unproductive conditions overall.

Although this book is primarily about Britain, the two non-European contributions are particularly important as they partly open the door on the global view. The rest of the world can offer models to explain the record in Britain and northwest Europe: the importance of fire and forest gardens, for example. Once we look beyond traditional European agricultural models, we find that human adtivity affects all kinds of land- scapes (indeed, some regions of tropical forest that used to be considered “undisturbed” turn out to have been heavily influenced by human action in recent times). As the editor points out, the better we understand the past interaction of humans and landscapes, the better we can predict possible trajectories in relation to current human action: diversity patterns, soil quality changes, and wetlands dynamics, for example.

One comes away from this book with an appreciation of the different emphases placed on human impact in British and American paleoecology. British studies often reveal a history of vegetation and landscape development in which human impact plays an important role. North American researchers, a t least until recently, have focused on “natural” systems and have assumed that they are dealing mainly with climate-based landscape transformations; vegetation change may form a backdrop against which a cultural story unfolds, but people and landscape are generally not seen to interact-until Europeans arrive. This is a view that may need to be revised, and it will be interesting to follow developments in North America and other regions of the world as new studies in paleoecology and environmental geology evolve.

This book is sometimes fascinating and sometimes frustrating, which is prob- ably inevitable when such diverse material is collated. However, it contains some

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excellent case studies, a good bibliography, and some challenging ideas, and I recommend it to anyone interested in human-impact paleoecology and environmental archaeology.

Mary Edwards Alaska Quaternary Center

University of Alaska-Fairbanks 907 Yukon Drive

Fairbanks, Alaska 99709

Practices of Archaeological Stratigraphy. Edward C. Harris, Marley R. Brown 111, and Gregory J. Brown (Editors), 1993, Academic Press, viii + 296 pp. $64.00 (hardbound).

This is the latest contribution of Edward Harris to the methodology of stratigraphic practice on archaeological sites, in this case aided and abetted by colleagues who have employed the Harris Method in their excavations in the Old and New Worlds. The Harris Method has several components. It is best known for the so-called Harris Matrix, a stratigraphic recording system designed and named by Harris himself, but also in- cludes open-area excavation, single-context planning, and attention to interfaces.

The volume begins with a foreward by Norman Hammond and an introduction to the basic tenets of the Harris Method by the editors. This is followed by a chapter on “Interfaces in Archaeological Stratigraphy” by M. R. Brown I11 and Harris, which they use as a forum for rebutting critics of Harris’s previous publications, the present reviewer included. Their emphasis on interfaces seems exaggerated, although necessary perhaps to encourage proper thinking in stratigraphy. They would encourage the stratigrapher to label or number an interface as an explicit “unit of stratification” along with all the physical deposits (or contexts) in the site rather than leaving its recognition tacit. They wrongly criticize geological stratigraphers for not dealing with interfaces. Every geological deposit (layer, bed, or formation) is properly defined not only by its composi- tion but also by the nature of its interfaces (called contacts or boundaries) with adjacent deposits. In their enthusiasm they state also that “there are generally more interfaces than deposits on most archaeological sites” (p. 161, which may be true for some very complex sites, but not for “most” sites.

The remaining papers are organized according to “Historical Trends,” “Analysis in Excavation,” “Phasing and Structural Analysis,” “Post-Excavation Analysis,” and “Fu- ture Developments.”

Craig Spence presents an interesting, brief history of the recording systems used in the City of London excavations over 200 years, followed by rather detailed description of the “single-context” recording system introduced in the early 1970s. This is a very pragmatic and useful chapter for anyone planning or participating in any kind of excavation.

Isabel Tr6coli reviews archaeology in Spain. In the late 1970s, the Harris Method

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