Chris S. Duvall

Human settlement ecology and chimpanzee habitat selection in Mali

Customary land-use practices create distinctive cultural landscapes, including landscapes where abandoned settlements host vegetation that attracts wild animals. Understanding how landscape patterns relate to land-use history can help clarify the ecological effects of particular land uses. This study examines relationships between chimpanzee habitat selection and Maninka settlement practice, to determine how settlement history has affected chimpanzee habitat in Mali’s Bafing Biosphere Reserve, where conservation practitioners assume that the characteristic settlement pattern reflects a process of settlement expansion into undisturbed habitat. Three types of data are reported: (1) ethnographic interviews on settlement history and practice; (2) systematic sampling of chimpanzee habitat use; and (3) ground-based mapping of settlement sites, surface water, and fruit-tree patches. These data show that the Maninka have a shifting settlement system, meaning that most sites are occupied for only relatively brief periods; and that some abandoned settlement sites host fruit-tree patches that are seasonally important chimpanzee habitat. Two main conclusions are: (1) settlement expansion has not occurred; instead, historic settlement has created habitat that is both attractive and available to chimpanzees. Anthropogenic habitat does not appear to be vital for chimpanzee survival, but it spatially and temporally supplements natural habitats. (2) Conservation policies meant to reduce the presumed threat of settlement expansion may have initiated an unintended, long-term threat of habitat loss for chimpanzees. While settlement practices may be a component of short-term threats to chimpanzees, such as hunting, when addressing these threats conservation practitioners should consider long-term settlement processes to avoid creating new threats.

Biocomplexity from the Ground Up: Vegetation Patterns in a West African Savanna Landscape

Most studies of vegetation in African savannas have adopted reductionist approaches to research, mostly by looking at only “natural” or “anthropogenic” spaces in focal landscapes. Few have considered how social and biophysical factors interact to create vegetation patterns across landscapes. More holistic understanding of pattern–process relationships across savanna landscapes as wholes is needed to manage the ecological connections of global and local change. To understand how process interactions create vegetation patterns in a savanna landscape, I sampled vegetation in 217 sites in southwestern Mali, where conditions are similar to many parts of West Africa. For each site, I collected site-specific data on several biophysical factors as well as histories of settlement or cultivation, based on ethnographic interviews. Hierarchical clustering, indicator species analysis, multiresponse permutation procedures, and nonmetric multidimensional scaling revealed patterns of floristic variation across the landscape that related to patterns of biophysical variation and disturbance history. The results show complexity in terms of both pattern and process. Patterns evident at different scales of organization are not necessarily congruent, and vegetation heterogeneity is greater than expected based on any subset of biophysical or social processes. Soil moisture, bedrock lithology, and disturbance history are particularly important in shaping vegetation characteristics. Complex patterns arise because vegetation shows three different responses to settlement and cultivation—turnover, homogenization, and resilience—with actual outcomes that depend on site-specific biophysical and social conditions. This research shows that research epistemology can shape physical geographic knowledge and that savanna landscapes must be seen as entities with characteristics that are maintained through human–environment interaction.

Important Habitat for Chimpanzees in Mali

Analysis of botanical data is presented from the standpoint of chimpanzee natural history. The Sudano-Guinean gallery forest type dominated by the tree Gilletiodendron glandulosum appears to be important habitat for chimpanzees due to vegetation structure, presence of permanent surface water, and, particularly, abundance of diverse food plants throughout the year. Based on fecal analysis, observation of feeding remains, observation of sympatric primates, ethnographic research, and literature review, sixty probable chimpanzee food plants have been identified in the Gilletiodendron forest of Mali. Phytogeographical analysis indicates that chimpanzees in Mali’s Sudanian climate zone eat mainly Sudano-Guinean plant species. Heavy reliance on Sudano-Guinean vegetation may indicate that modern chimpanzee populations in savanna areas are relicts, and that the species was originally adapted to mesic Guinean forests. There appears to be niche separation based on topography between humans and chimpanzees which breaks down in times of human food shortage, and the potential for competition is high.

Visualizing nutritional terrain: A geospatial analysis of pedestrian produce accessibility in Lansing, Michigan, USA

This article considers how geospatial analyses can influence cartographic outputs in studies of the spatial structure of food environments. We make two contributions. First, we present a new approach to conceiving and visualizing urban food environments as ‘nutritional terrains’, in which the opportunities and costs of locating (healthful) food vary continuously across space. While other researchers have conceptualized and represented food environments as continuous phenomena, we use detailed data to produce maps of food accessibility that have high resolution both spatially and in terms of food availability. Second, we show that decisions made about measuring and modelling food accessibility can create artifactual patterns independently of actual variation in food-environment characteristics. Although the type of method-driven patterning we identify will not surprise cartographers, we argue that non-geographers using geographic information technologies to visualize food environments must give greater attention to the unintended consequences of choices made in geospatial analyses.

CLASSIFYING PHYSICAL GEOGRAPHIC FEATURES: THE CASE OF MANINKA FARMERS IN SOUTHWESTERN MALI

Abstract. This article argues that understanding how people classify physical geographic features is necessary for identifying fundamental, cross‐cultural geographic concepts that are required for successful communication of geographic knowledge. Academic geographers have not given sufficient attention to systems of local geographic knowledge, even though promising theoretical frameworks exist, particularly in the field of ethnoecology. However, the research approach that has characterized ethnoecology is insufficient to develop ethnogeography as a field of inquiry, because ethnoecologists have overemphasized limited aspects of local knowledge systems, such as soils, which has often led researchers to incompletely sample local knowledge systems. Using ethnographic methods, this article analyses the content and structure of physical geographic knowledge in the Maninka language as spoken in southwestern Mali, and compares Maninka knowledge to that of other cultural groups. The results suggest that broad physical geographic concepts may be shared pan‐environmentally, but that most physical geographic knowledge is contained in culturally specific classifications embedded within a broad cross‐cultural framework. Academic geographers should expect only broad correspondence between their categories of physical geographic variation and those of people who classify biophysical features according to local knowledge systems. Finally, this article also shows that ethnoecological research will be advanced if geographic theories of place are given more prominence in ethnoecological studies.

Apples and oranges? Classifying food retailers in a midwestern US city based on the availability of fresh produce.

Classifying food retailers is an important step in spatial analyses of food environments for public health research, but current classification methods would benefit from refinement. We classified 94 retailers in Lansing, Michigan, based on the availability of 446 produce items. We compare our classification to groupings based on physical characteristics of stores, which provide indirect information on food availability and are widely used to classify food retailers. We found some justification for 3 commonly used categories (supermarket, grocer, and convenience store). However, additional categories of ethnic food specialist and organic specialist grocers are necessary to summarize variation in food availability, which correlates weakly with physical characteristics of stores.

Drug laws, bioprospecting and the agricultural heritage of Cannabis in Africa

For centuries across most of Africa, farmers have valued Cannabis for multiple reasons. Historic crop selection produced genetic diversity that commercial bioprospectors value for marijuana production. African colonial and post-colonial administrations devalued the crop, enacted Cannabis controls earlier than most locations worldwide, and excluded Cannabis from agricultural development initiatives. Public agricultural institutions exclude Cannabis as an extension of drug-control policies. Only private companies conserve crop genetic diversity for psychoactive Cannabis, without recognizing intellectual property rights embedded in landraces. Cannabis decriminalization initiatives should stimulate evaluation of its roles in African agriculture, and of worldwide control and management of its genetic diversity.

The Trouble with Savanna and Other Environmental Categories, Especially in Africa

Environmental categories are simplifications of reality meant to enable generalization, which is necessary to produce predictive physical geographic knowledge. We argue here that these categories are social constructions related to ideas shared broadly in society, including environmental deterministic explanations of human difference. The biophysical, philosophical, and sociocultural problems associated with environmental categories are exemplified by ‘savanna’ in Africa. Examining environmental categorization is an important point of engagement in critical physical geography because it is a social process, explicitly centered on simplification and generalization, and significant broadly across scientific practice and society.

Science, Society, and Knowledge of the Columbian Exchange: The Case of Cannabis

This chapter argues that botanical scientific knowledge of Cannabis has shaped its environmental historiography. This chapter engages the epistemological concerns of science and technology studies (STS) by examining how botanists have conceived biological speciation; it contributes to environmental history by showing that concepts of speciation—at least for domesticated taxa—bear narratives of human history that shape and constrain imperatives for historical research. Dominant concepts of Cannabis taxonomy have enabled biological hypotheses to substitute for historical evidence, thereby reducing imperatives to research the plant’s transatlantic dispersal history. Historiographical neglect has enabled a Eurocentric narrative of Cannabis that is not supported by the documentary record. The chapter proposes a historiography for Cannabis that is more attentive to past social, cultural, and environmental contexts.

African Fire Cultures, Cattle Ranching, and Colonial Landscape Transformations in the Neotropics

Abstract Fire regimes emerge partly from human activities that reflect cultural‐ecological knowledge of the relationships among fire, vegetation, grazing, climate, and other variables, as well as social relations. More knowledge of such “fire cultures,” past and present, therefore remains necessary to better understand the causes and persistent consequences of landscape burning. In the neotropics, people have used fire for centuries to manage livestock pastures. Conventional wisdom has long posited that such practices derived solely from antecedent European and indigenous, Native American fire cultures. Analysis of accounts of rangeland burning from throughout the neotropics during colonial times, however, demonstrates that ranchers incorporated African fire cultures and that the timing of burning shifted from early during the dry season in the sixteenth century to late during the dry season by the nineteenth century.